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Sample records for reaction cell drc

  1. Determination of (90)Sr in soil samples using inductively coupled plasma mass spectrometry equipped with dynamic reaction cell (ICP-DRC-MS).

    Science.gov (United States)

    Feuerstein, J; Boulyga, S F; Galler, P; Stingeder, G; Prohaska, T

    2008-11-01

    A rapid method is reported for the determination of (90)Sr in contaminated soil samples in the vicinity of the Chernobyl Nuclear Power Plant by ICP-DRC-MS. Sample preparation and measurement procedures focus on overcoming the isobaric interference of (90)Zr, which is present in soils at concentrations higher by more than six orders of magnitude than (90)Sr. Zirconium was separated from strontium in two steps to reduce the interference by (90)Zr(+) ions by a factor of more than 10(7): (i) by ion exchange using a Sr-specific resin and (ii) by reaction with oxygen as reaction gas in a dynamic reaction cell (DRC) of a quadrupole ICP-MS. The relative abundance sensitivity of the ICP-MS was studied systematically and the peak tailing originating from (88)Sr on mass 90 u was found to be about 3 x 10(-9). Detection limits of 4 fg g(-1) (0.02 Bq g(-1)) were achieved when measuring Sr solutions containing no Zr. In digested uncontaminated soil samples after matrix separation as well as in a solution of 5 microg g(-1) Sr and 50 ng g(-1) Zr a detection limit of 0.2 pg g(-1) soil (1 Bq g(-1) soil) was determined. (90)Sr concentrations in three soil samples collected in the vicinity of the Chernobyl Nuclear Power Plant were 4.66+/-0.27, 13.48+/-0.68 and 12.9+/-1.5 pg g(-1) corresponding to specific activities of 23.7+/-1.3, 68.6+/-3.5 and 65.6+/-7.8 Bq g(-1), respectively. The ICP-DRC-MS results were compared to the activities measured earlier by radiometry. Although the ICP-DRC-MS is inferior to commonly used radiometric methods with respect to the achievable minimum detectable activity it represents a time- and cost-effective alternative technique for fast monitoring of high-level (90)Sr contamination in environmental or nuclear industrial samples down to activities of about 1 Bq g(-1).

  2. Determination of 90Sr in soil samples using inductively coupled plasma mass spectrometry equipped with dynamic reaction cell (ICP-DRC-MS)

    International Nuclear Information System (INIS)

    Feuerstein, J.; Boulyga, S.F.; Galler, P.; Stingeder, G.; Prohaska, T.

    2008-01-01

    A rapid method is reported for the determination of 90 Sr in contaminated soil samples in the vicinity of the Chernobyl Nuclear Power Plant by ICP-DRC-MS. Sample preparation and measurement procedures focus on overcoming the isobaric interference of 90 Zr, which is present in soils at concentrations higher by more than six orders of magnitude than 90 Sr. Zirconium was separated from strontium in two steps to reduce the interference by 90 Zr + ions by a factor of more than 10 7 : (i) by ion exchange using a Sr-specific resin and (ii) by reaction with oxygen as reaction gas in a dynamic reaction cell (DRC) of a quadrupole ICP-MS. The relative abundance sensitivity of the ICP-MS was studied systematically and the peak tailing originating from 88 Sr on mass 90 u was found to be about 3 x 10 -9 . Detection limits of 4 fg g -1 (0.02 Bq g -1 ) were achieved when measuring Sr solutions containing no Zr. In digested uncontaminated soil samples after matrix separation as well as in a solution of 5 μg g -1 Sr and 50 ng g -1 Zr a detection limit of 0.2 pg g -1 soil (1 Bq g -1 soil) was determined. 90 Sr concentrations in three soil samples collected in the vicinity of the Chernobyl Nuclear Power Plant were 4.66 ± 0.27, 13.48 ± 0.68 and 12.9 ± 1.5 pg g -1 corresponding to specific activities of 23.7 ± 1.3, 68.6 ± 3.5 and 65.6 ± 7.8 Bq g -1 , respectively. The ICP-DRC-MS results were compared to the activities measured earlier by radiometry. Although the ICP-DRC-MS is inferior to commonly used radiometric methods with respect to the achievable minimum detectable activity it represents a time- and cost-effective alternative technique for fast monitoring of high-level 90 Sr contamination in environmental or nuclear industrial samples down to activities of about 1 Bq g -1

  3. Determination of {sup 90}Sr in soil samples using inductively coupled plasma mass spectrometry equipped with dynamic reaction cell (ICP-DRC-MS)

    Energy Technology Data Exchange (ETDEWEB)

    Feuerstein, J.; Boulyga, S.F.; Galler, P.; Stingeder, G. [Department of Chemistry, Division of Analytical Chemistry-VIRIS Laboratory, University of Natural Resources and Applied Life Sciences, Muthgasse 18, A-1190 Vienna (Austria); Prohaska, T. [Department of Chemistry, Division of Analytical Chemistry-VIRIS Laboratory, University of Natural Resources and Applied Life Sciences, Muthgasse 18, A-1190 Vienna (Austria)], E-mail: thomas.prohaska@boku.ac.at

    2008-11-15

    A rapid method is reported for the determination of {sup 90}Sr in contaminated soil samples in the vicinity of the Chernobyl Nuclear Power Plant by ICP-DRC-MS. Sample preparation and measurement procedures focus on overcoming the isobaric interference of {sup 90}Zr, which is present in soils at concentrations higher by more than six orders of magnitude than {sup 90}Sr. Zirconium was separated from strontium in two steps to reduce the interference by {sup 90}Zr{sup +} ions by a factor of more than 10{sup 7}: (i) by ion exchange using a Sr-specific resin and (ii) by reaction with oxygen as reaction gas in a dynamic reaction cell (DRC) of a quadrupole ICP-MS. The relative abundance sensitivity of the ICP-MS was studied systematically and the peak tailing originating from {sup 88}Sr on mass 90 u was found to be about 3 x 10{sup -9}. Detection limits of 4 fg g{sup -1} (0.02 Bq g{sup -1}) were achieved when measuring Sr solutions containing no Zr. In digested uncontaminated soil samples after matrix separation as well as in a solution of 5 {mu}g g{sup -1} Sr and 50 ng g{sup -1} Zr a detection limit of 0.2 pg g{sup -1} soil (1 Bq g{sup -1} soil) was determined. {sup 90}Sr concentrations in three soil samples collected in the vicinity of the Chernobyl Nuclear Power Plant were 4.66 {+-} 0.27, 13.48 {+-} 0.68 and 12.9 {+-} 1.5 pg g{sup -1} corresponding to specific activities of 23.7 {+-} 1.3, 68.6 {+-} 3.5 and 65.6 {+-} 7.8 Bq g{sup -1}, respectively. The ICP-DRC-MS results were compared to the activities measured earlier by radiometry. Although the ICP-DRC-MS is inferior to commonly used radiometric methods with respect to the achievable minimum detectable activity it represents a time- and cost-effective alternative technique for fast monitoring of high-level {sup 90}Sr contamination in environmental or nuclear industrial samples down to activities of about 1 Bq g{sup -1}.

  4. Exploiting dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS) for sequential determination of trace elements in blood using a dilute-and-shoot procedure

    International Nuclear Information System (INIS)

    Lemos Batista, Bruno; Lisboa Rodrigues, Jairo; Andrade Nunes, Juliana; Oliveira Souza, Vanessa Cristina de; Barbosa, Fernando

    2009-01-01

    Inductively coupled plasma mass spectrometry with quadrupole (q-ICP-MS) and dynamic reaction cell (DRC-ICP-MS) were evaluated for sequential determination of As, Cd, Co, Cr, Cu, Mn, Pb, Se, Tl, V and Zn in blood. The method requires as little as 100 μL of blood. Prior to analysis, samples (100 μL) were diluted 1:50 in a solution containing 0.01% (v/v) Triton X-100 and 0.5% (v/v) nitric acid. The use of the DRC was only mandatory for Cr, Cu, V and Zn. For the other elements the equipment may be operated in a standard mode (q-ICP-MS). Ammonia was used as reaction gas. Selection of best flow rate of ammonium gas and optimization of the quadrupole dynamic band-pass tuning parameter (RPq) were carried out, using a ovine base blood for Cr and V and a synthetic matrix solution (SMS) for Zn and Cu diluted 1:50 and spiked to contain 1 μg L -1 of each element. Method detection limits (3 s) for 75 As, 114 Cd, 59 Co, 51 Cr, 63 Cu 55 Mn, 208 Pb, 82 Se, 205 Tl, 51 V, and 64 Zn were 14.0, 3.0, 11.0, 7.0, 280, 9.0, 3.0, 264, 0.7, 6.0 and 800 ng L -1 , respectively. Method validation was accomplished by the analysis of blood Reference Materials produced by the L'Institut National de Sante Publique du Quebec (Canada).

  5. Multi-element analysis of urine using dynamic reaction cell inductively coupled plasma mass spectrometry (ICP-DRC-MS — A practical application

    Directory of Open Access Journals (Sweden)

    Renata Brodzka

    2013-04-01

    Full Text Available Objectives: The method for the determination of As, Al, Cd, Ni, Pb (toxic elements and Cr, Co, Cu, Fe, Mn, Zn (essential elements in human urine by the use of Inductively Coupled Plasma Mass Spectrometry (quadrupole ICP-MS DRCe Elan, Perkin Elmer with the dynamic reaction cell (DRC was developed. Materials and Methods: The method has been applied for multi-element analysis of the urine of 16 non-exposed healthy volunteers and 27 workers employed in a copper smelter. The analysis was conducted after initial 10-fold dilution of the urine samples with 0,1% nitric acid. Rhodium was used as an internal standard. The method validation parameters such as detection limit, sensitivity, precision were described for all elements. Accuracy of the method was checked by the regular use of certified reference materials ClinCheck®-Control Urine (Recipe as well as by participation of the laboratory in the German External Quality Assessment Scheme (G-EQUAS. Results: The detection limits (DL 3s of the applied method were 0.025, 0.007, 0.002, 0.004, 0.004, 0.086, 0.037, 0.009, 0.016, 0.008, 0.064 (μg/l for Al, As, Cd, Cr, Co, Cu, Fe, Mn, Ni, Pb, Zn in urine, respectively. For each element linearity with correlation coefficient of at least 0.999 was determined. Spectral interferences from some of the ions were removed using DRC-e with addition of alternative gas: methane for cobalt, copper, cadmium, chromium, iron, manganese, nickel and rhodium, and oxygen for arsenic. Conclusions: The developed method allows to determine simultaneously eleven elements in the urine with low detection limits, high sensitivity and good accuracy. Moreover, the method is appropriate for the assessment of both environmental and occupational exposure.

  6. Review of EU Conflict Management in DRC

    DEFF Research Database (Denmark)

    Mandrup, Thomas

    2016-01-01

    The report present the backdrop on EU's involvement in the DRC conflict, its history, the nature of the conflict......The report present the backdrop on EU's involvement in the DRC conflict, its history, the nature of the conflict...

  7. Strategies for method development for an inductively coupled plasma mass spectrometer with bandpass reaction cell. Approaches with different reaction gases for the determination of selenium

    International Nuclear Information System (INIS)

    Hattendorf, Bodo; Guenther, Detlef

    2003-01-01

    An inductively coupled plasma mass spectrometer with dynamic reaction cell (DRC) was used to investigate different approaches for chemical resolution of Ar 2 + ions and to improve the determination of Se. Hydrogen, methane, oxygen and nitrous oxide were used as reaction gases. The method development for each approach consists of the acquisition of spectra for blank and spiked samples at different operating parameters, including reaction gas flow and transmission settings, of the DRC. Isotope ratio studies and the analytes signal to background ratio (SBR), were used as criteria to determine the operating conditions of the DRC where spectral interferences from the ion source or from polyatomic ions formed inside the DRC are minimized. Methane was found to provide the highest reaction efficiency for determination of Se. Nitrous oxide and oxygen also very efficiently suppress the Ar 2 + interference but reaction or scattering losses of Se + and SeO + are significant. Hydrogen is the least efficient gas for Ar 2 + reduction but little scattering or reactive loss lead to a good SBR. The determination of Se as SeO + was investigated with oxygen and nitrous oxide as reaction gases. The efficiency when using the oxygenation reaction was found to be similar to the efficiency for the charge transfer reactions but the slow oxygenation of the potentially interfering Mo + renders this approach less useful for analytical purposes. Using a natural water sample it could be shown that very good agreement is obtained using methane or hydrogen for analysis of 80 Se + at the μg/l level. Limits of detection are lowest (2 ng/l) when methane is used to suppress the Ar 2 + ion and when 80 Se + is used for analysis

  8. Ion-neutral gas reactions in a collision/reaction cell in inductively coupled plasma mass spectrometry: Correlation of ion signal decrease to kinetic rate constants

    Energy Technology Data Exchange (ETDEWEB)

    Gray, Patrick J. [Trace Element Research Laboratory, School of Earth Sciences, The Ohio State University, 125 S. Oval Mall, Columbus, OH 43210 (United States); Department of Chemistry, The Ohio State University, 120 18th Avenue, Columbus, OH 43210 (United States); Olesik, John W., E-mail: olesik.2@osu.edu [Trace Element Research Laboratory, School of Earth Sciences, The Ohio State University, 125 S. Oval Mall, Columbus, OH 43210 (United States)

    2015-03-01

    Reaction gas flow rate dependent Ar{sub 2}{sup +} and Ar{sup +} signals are correlated to fundamental kinetic rate coefficients. A simple calculation, assuming that gas exits the reaction cell due only to effusion, is described to estimate the gas pressure in the reaction cell. The value of the product of the kinetic rate constant and the ion residence time in the reaction cell can be determined from experimental measurement of the decrease in an ion signal as a function of reaction gas flow rate. New kinetic rate constants are determined for the reaction of CH{sub 3}F with Ar{sup +} and Ar{sub 2}{sup +}. - Highlights: • How to determine pressure and the product of the kinetic rate constant times the ion residence time in reaction cell • Relate measured ICP-DRC-MS signals versus gas flow rate to kinetic rate constants measured previously using SIFT-MS • Describe how to determine previously unmeasured kinetic rate constants using ICP-DRC-MS.

  9. Optimization and application of ICPMS with dynamic reaction cell for precise determination of 44Ca/40Ca isotope ratios.

    Science.gov (United States)

    Boulyga, Sergei F; Klötzli, Urs; Stingeder, Gerhard; Prohaska, Thomas

    2007-10-15

    An inductively coupled plasma mass spectrometer with dynamic reaction cell (ICP-DRC-MS) was optimized for determining (44)Ca/(40)Ca isotope ratios in aqueous solutions with respect to (i) repeatability, (ii) robustness, and (iii) stability. Ammonia as reaction gas allowed both the removal of (40)Ar+ interference on (40)Ca+ and collisional damping of ion density fluctuations of an ion beam extracted from an ICP. The effect of laboratory conditions as well as ICP-DRC-MS parameters such a nebulizer gas flow rate, rf power, lens potential, dwell time, or DRC parameters on precision and mass bias was studied. Precision (calculated using the "unbiased" or "n - 1" method) of a single isotope ratio measurement of a 60 ng g(-1) calcium solution (analysis time of 6 min) is routinely achievable in the range of 0.03-0.05%, which corresponded to the standard error of the mean value (n = 6) of 0.012-0.020%. These experimentally observed RSDs were close to theoretical precision values given by counting statistics. Accuracy of measured isotope ratios was assessed by comparative measurements of the same samples by ICP-DRC-MS and thermal ionization mass spectrometry (TIMS) by using isotope dilution with a (43)Ca-(48)Ca double spike. The analysis time in both cases was 1 h per analysis (10 blocks, each 6 min). The delta(44)Ca values measured by TIMS and ICP-DRC-MS with double-spike calibration in two samples (Ca ICP standard solution and digested NIST 1486 bone meal) coincided within the obtained precision. Although the applied isotope dilution with (43)Ca-(48)Ca double-spike compensates for time-dependent deviations of mass bias and allows achieving accurate results, this approach makes it necessary to measure an additional isotope pair, reducing the overall analysis time per isotope or increasing the total analysis time. Further development of external calibration by using a bracketing method would allow a wider use of ICP-DRC-MS for routine calcium isotopic measurements, but it

  10. Congolese women activists in DRC and Belgium

    Directory of Open Access Journals (Sweden)

    Marie Godin

    2010-11-01

    Full Text Available Congolese women are energetically engaged in peacebuilding, both in DRC and abroad.Their voices – inspired by different experiences and presenting different perspectives – deserve greater recognition.

  11. Accelerated thermal and radiative ageing of hydrogenated NBR for DRC

    International Nuclear Information System (INIS)

    Mares, G.; Notingher, P.

    1996-01-01

    The accelerated thermal and gamma radiation ageing of HNBR carbon black-T80 has been studied by measuring the residual deformation under constant deflection -- DRC, in air, using a relevant equation for the relaxation phenomena. The residual deformation under constant deflection during the process of accelerated ageing is increasing but the structure of polymer answers in the proper manner to the mechanical stress. The degradation equations were obtained, using Alfrey model for the relaxation polymer subject to compression and an Arrhenius dependence for the chemical reaction rate. The inverted relaxation time for the thermal degradation is depending on the chemical reaction rate and the dose rate of gamma radiation

  12. Analysis of whole human blood for Pb, Cd, Hg, Se, and Mn by ICP-DRC-MS for biomonitoring and acute exposures.

    Science.gov (United States)

    Jones, Deanna R; Jarrett, Jeffery M; Tevis, Denise S; Franklin, Melanie; Mullinix, Neva J; Wallon, Kristen L; Derrick Quarles, C; Caldwell, Kathleen L; Jones, Robert L

    2017-01-01

    We improved our inductively coupled plasma mass spectrometry (ICP-MS) whole blood method [1] for determination of lead (Pb), cadmium (Cd), and mercury (Hg) by including manganese (Mn) and selenium (Se), and expanding the calibration range of all analytes. The method is validated on a PerkinElmer (PE) ELAN® DRC II ICP-MS (ICP-DRC-MS) and uses the Dynamic Reaction Cell (DRC) technology to attenuate interfering background ion signals via ion-molecule reactions. Methane gas (CH 4 ) eliminates background signal from 40 Ar 2 + to permit determination of 80 Se + , and oxygen gas (O 2 ) eliminates several polyatomic interferences (e.g. 40 Ar 15 N + , 54 Fe 1 H + ) on 55 Mn + . Hg sensitivity in DRC mode is a factor of two higher than vented mode when measured under the same DRC conditions as Mn due to collisional focusing of the ion beam. To compensate for the expanded method's longer analysis time (due to DRC mode pause delays), we implemented an SC4-FAST autosampler (ESI Scientific, Omaha, NE), which vacuum loads the sample onto a loop, to keep the sample-to-sample measurement time to less than 5min, allowing for preparation and analysis of 60 samples in an 8-h work shift. The longer analysis time also resulted in faster breakdown of the hydrocarbon oil in the interface roughing pump. The replacement of the standard roughing pump with a pump using a fluorinated lubricant, Fomblin®, extended the time between pump maintenance. We optimized the diluent and rinse solution components to reduce carryover from high concentration samples and prevent the formation of precipitates. We performed a robust calculation to determine the following limits of detection (LOD) in whole blood: 0.07µgdL -1 for Pb, 0.10µgL -1 for Cd, 0.28μgL -1 for Hg, 0.99µgL -1 for Mn, and 24.5µgL -1 for Se. Published by Elsevier B.V.

  13. Optimization of LC-DRC-ICP-MS for the speciation of selenotrisulfides with simultaneous detection of sulfur and selenium as oxides combined with determination of elemental and isotope ratios

    DEFF Research Database (Denmark)

    Sturup, S.; Bendahl, L.; Gammelgaard, B.

    2006-01-01

    A LC-DRC-ICP-MS method for the simultaneous detection of selenium and Sulfur in the selenotrisulfides selenocysteineglutathione (Cys-Se-SG) and selenodiglutathione (GS-Se-SG) is described. Both sulfur and selenium are reacted with oxygen in the dynamic reaction cell (DRC) and detected as oxides....... The selenotrisulfides were separated applying a 30 rnin gradient liquid chromatographic (LC) method with a formic acid/methanol eluent. The detection limits for sulfur (as (SO+)-S-32-O-16) and selenium (as (SeO+)-Se-80-O-16) in the chromatographic system were 4.0 and 0.2 mu g L-1 (100 and 5 ng in absolute mass units...

  14. Poverty, population growth, and youth violence in DRC's cities ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2016-04-28

    Apr 28, 2016 ... Poverty, population growth, and youth violence in DRC's cities ... Learn more about what drives DRC's urban violence and how it is linked to poverty ... ​Youth violence and the shift of land disputes from rural communities into ...

  15. Beyond the silence: sexual violence in eastern DRC

    Directory of Open Access Journals (Sweden)

    Jessica Keralis

    2010-11-01

    Full Text Available The sexual violence laws introduced in DRC in 2006 have had only limited impact. A much louder condemnation of rape and a far more proactive approach to prevention are urgently needed.

  16. Uranium analysis in urine by inductively coupled plasma dynamic reaction cell mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ejnik, John W. [Northern Michigan University, Chemistry Department, Marquette, MI (United States); Todorov, Todor I.; Mullick, Florabel G.; Centeno, Jose A. [Armed Forces Institute of Pathology (AFIP), Division of Biophysical Toxicology, Washington, DC (United States); Squibb, Katherine; McDiarmid, Melissa A. [University of Maryland, School of Medicine, Baltimore, MD (United States)

    2005-05-01

    Urine uranium concentrations are the best biological indicator for identifying exposure to depleted uranium (DU). Internal exposure to DU causes an increased amount of urine uranium and a decreased ratio of {sup 235}U/{sup 238}U in urine samples, resulting in measurements that vary between 0.00725 and 0.002 (i.e., natural and depleted uranium's {sup 235}U/{sup 238}U ratios, respectively). A method based on inductively coupled plasma dynamic reaction cell mass spectrometry (ICP-DRC-MS) was utilized to identify DU in urine by measuring the quantity of total U and the {sup 235}U/{sup 238}U ratio. The quantitative analysis was achieved using {sup 233}U as an internal standard. The analysis was performed both with and without the reaction gas oxygen. The reaction gas converted ionized {sup 235}U{sup +} and {sup 238}U{sup +} into {sup 235}UO{sub 2}{sup +} (m/z=267) and {sup 238}UO{sub 2}{sup +} (m/z=270). This conversion was determined to be over 90% efficient. A polyatomic interference at m/z 234.8 was successfully removed from the {sup 235}U signal under either DRC operating conditions (with or without oxygen as a reaction gas). The method was validated with 15 urine samples of known uranium compositions. The method detection limit for quantification was determined to be 0.1 pg U mL{sup -1} urine and an average coefficient of variation (CV) of 1-2% within the sample measurements. The method detection limit for determining {sup 235}U/{sup 238}U ratio was 3.0 pg U mL{sup -1} urine. An additional 21 patient samples were analyzed with no information about medical history. The measured {sup 235}U/{sup 238}U ratio within the urine samples correctly identified the presence or absence of internal DU exposure in all 21 patients. (orig.)

  17. Insecurity in the DRC: The Obstacle to Peace and Stability

    Science.gov (United States)

    2016-12-01

    Mouvement de Liberation du Congo, (MLC), Including Leadership and Treatment of Party Members (2009-2012),” refworld: Democratic Republic of Congo, March...DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) The Democratic Republic of Congo (DRC) has experienced complex warfare that has involved various...economy, and better relations with neighboring countries. 14. SUBJECT TERMS Democratic Republic of Congo, disarmament, demobilization

  18. Performance evaluation of cellular layouts : extension to DRC system contexts

    NARCIS (Netherlands)

    Suresh, NC; Gaalman, GJC

    This study involves a comparison of the performance of functional layouts (FL) and cellular manufacturing (CM) systems in a dual-resource-constrained( DRC) system context. Past studies of FL and CM have been based mostly on single-resource-constrained( SRC) systems. Recent studies have included

  19. Onchocerciasis control in the Democratic Republic of Congo (DRC): challenges in a post-war environment.

    Science.gov (United States)

    Makenga Bof, J-C; Maketa, V; Bakajika, D K; Ntumba, F; Mpunga, D; Murdoch, M E; Hopkins, A; Noma, M M; Zouré, H; Tekle, A H; Katabarwa, M N; Lutumba, P

    2015-01-01

    To evaluate onchocerciasis control activities in the Democratic Republic of Congo (DRC) in the first 12 years of community-directed treatment with ivermectin (CDTI). Data from the National Programme for Onchocerciasis (NPO) provided by the National Onchocerciasis Task Force (NOTF) through the annual reports of the 21 CDTI projects for the years 2001-2012 were reviewed retrospectively. A hypothetical-inputs-process-outputs-outcomes table was constructed. Community-directed treatment with ivermectin expanded from 1968 communities in 2001 to 39 100 communities by 2012 while the number of community-directed distributors (CDD) and health workers (HW) multiplied. By 2012, there were ratios of 1 CDD per 262 persons and 1 HW per 2318 persons at risk. More than 80% of the funding came from the fiduciary funds of the African Programme for Onchocerciasis Control. The cost of treatment per person treated fell from US$ 1.1 in 2001 to US$ 0.1 in 2012. The therapeutic coverage increased from 2.7% (2001) to 74.2% (2012); the geographical coverage, from 4.7% (2001) to 93.9% (2012). Geographical coverage fell in 2005 due to deaths in loiasis co-endemic areas, and the therapeutic coverage fell in 2008 due to insecurity. Challenges to CDTI in DRC have been serious adverse reactions to ivermectin in loiasis co-endemic areas and political conflict. Targets for personnel or therapeutic and geographical coverages were not met. Longer term funding and renewed efforts are required to achieve control and elimination of onchocerciasis in DRC. © 2014 John Wiley & Sons Ltd.

  20. Cell reactions with biomaterials: the microscopies

    Directory of Open Access Journals (Sweden)

    Curtis A. S.G.

    2001-01-01

    Full Text Available The methods and results of optical microscopy that can be used to observe cell reactions to biomaterials are Interference Reflection Microscopy (IRM, Total Internal Reflection Fluorescence Microscopy (TIRFM, Surface Plasmon Resonance Microscopy (SPRM and Forster Resonance Energy Transfer Microscopy (FRETM and Standing Wave Fluorescence Microscopy. The last three are new developments, which have not yet been fully perfected. TIRFM and SPRM are evanescent wave methods. The physics of these methods depend upon optical phenomena at interfaces. All these methods give information on the dimensions of the gap between cell and the substratum to which it is adhering and thus are especially suited to work with biomaterials. IRM and FRETM can be used on opaque surfaces though image interpretation is especially difficult for IRM on a reflecting opaque surface. These methods are compared with several electron microscopical methods for studying cell adhesion to substrata. These methods all yield fairly consistent results and show that the cell to substratum distance on many materials is in the range 5 to 30 nm. The area of contact relative to the total projected area of the cell may vary from a few per cent to close to 100% depending on the cell type and substratum. These methods show that those discrete contact areas well known as focal contacts are frequently present. The results of FRETM suggest that the separation from the substratum even in a focal contact is about 5 nm.

  1. Contribution to the understanding of ion-gas reactions in ICP-MS collision reaction cells: application to the resolution of isobaric and polyatomic interferences

    International Nuclear Information System (INIS)

    Quemet, A.

    2012-01-01

    Inductively Coupled Plasma Mass Spectrometry (ICP-MS) emerged as the most essential technique in inorganic analytical chemistry thanks to its numerous assets, particularly its flexibility, its sensitivity and its reproducibility. As part of the elementary and isotopic analysis of irradiated fuel and transmutation target, the analyst is faced with a complex mass spectrum, due to the presence of many radionuclides. ICP-MS can not differentiate ions with the same mass, which induces isobaric and polyatomic interferences when the ions at the same mass are different chemical species. Last generations of ICP-MS have introduced collision reaction cells. It can in situ reduce these isobaric or polyatomic interferences. The cell is a multipole (quadrupole, hexapole or octupole) device filled with a collision and/or reaction gas. The gas molecules collide or possibly react with the ion beam, which eliminates or reduces interferences. Such resolution of interferences is based on the difference of chemical behaviours between the analyte and the interfering species: the choice of the gas is crucial. A better understanding of the 'ion - gas' reaction should help choosing the reacting gases. Three ICP-MS, with the different cell geometries, were used for this study: Perkin Elmer Elan DRC e (quadrupole), Thermo Fischer X serie II (hexapole) and Agilent Technologies 7700x (octupole). The effects of the cell geometry on different experimental parameters and on the resolution of the 56 Fe + / 40 Ar 16 O + polyatomic interferences were examined to measure iron at trace or ultra-trace level. This preliminary study was applied to measure iron as impurities in uranium oxide, the method was then validated with a Certified Reference Material. The reactivities of transition metals (Zr, Ru, Pd, Ag, Cd, Sn), lanthanides (La, Ce, Nd, Sm, Eu, Gd, Dy, Er and Yb) and actinides (U, Np, Pu, Am and Cm), elements of interest in the nuclear field, are studied with numerous gases (O 2 , CO, CO 2 , N 2

  2. Assessing fistula and obstetrical surgical capacity in South Kivu, DRC

    Directory of Open Access Journals (Sweden)

    Stephen C. Morris

    2013-01-01

    Full Text Available The Democratic Republic of Congo has suffered from decades of conflict and poverty. The Eastern DRC, in particular, continues to be a region dominated by instability, resulting in a fragmented health system. Governments and agencies interested in working towards improving health in the region are often challenged by an absence of knowledge of health metrics, limited capacity for health care delivery and overwhelming needs. The Harvard Humanitarian Initiative and Engender Health needs assessment, outlined in this report, demonstrates an effort to better understand the current state of surgical capacity in the region with an emphasis on needs and opportunities related to fistula repair.

  3. Simultaneous determination of Cr(iii) and Cr(vi) using reversed-phased ion-pairing liquid chromatography with dynamic reaction cell inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Wolf, R.E.; Morrison, J.M.; Goldhaber, M.B.

    2007-01-01

    A method for the simultaneous determination of Cr(iii) and Cr(vi) species in waters, soil leachates and synthetic bio-fluids is described. The method uses reversed-phase ion-pairing liquid chromatography to separate the chromium species and a dynamic reaction cell (DRC??) equipped ICP-MS for detection of chromium. Separation of the chromium species is carried out in less than 2 min. Cr(iii) is complexed with ethylenediaminetetraacetic acid (EDTA) prior to separation by mixing samples with the mobile phase containing 2.0 mM tetrabutylammonium hydroxide (TBAOH), 0.5 mM EDTA (dipotassium salt), and 5% (vol/vol) methanol, adjusted to pH 7.6. The interfering 40Ar 12C+ background peak at mass 52 was reduced by over four orders of magnitude to less than 200 cps by using 0.65 mL min-1 ammonia as a reaction gas and an RPq setting on the DRC of 0.75. Method detection limits (MDLs) of 0.09 ??g L-1 for Cr(iii) and 0.06 ??g L-1 for Cr(vi) were obtained based on peak areas at mass 52 for 50 ??L injections of low level spikes. Reproducibility at 2 ??g L-1 was 3% RSD for 5 replicate injections. The tolerance of the method to various levels of common cations and anions found in natural waters and to matrix constituents found in soil leachates and simulated gastric and lung fluids was tested by performing spike recovery calculations for a variety of samples. ?? The Royal Society of Chemistry.

  4. Barriers to modern contraceptive use in rural areas in DRC.

    Science.gov (United States)

    Muanda, Mbadu Fidèle; Ndongo, Gahungu Parfait; Messina, Lauren J; Bertrand, Jane T

    2017-09-01

    Recent research in the Democratic Republic of Congo (DRC) has shown that over a quarter of women have an unmet need for family planning and that modern contraceptive use is three times higher among urban than rural women. This study focuses on the reasons behind the choices of married men and women to use contraception or not. What are the barriers that have led to low levels of modern contraceptive use among women and men in DRC rural areas? The research team conducted 24 focus groups among women (non-users of any method, users of traditional methods and users of modern methods) and husbands (of non-users or users of traditional methods) in six health zones of three geographically dispersed provinces. The key barriers that emerged were poor spousal communication, sociocultural norms (especially the husband's role as primary decision-maker and the desire for a large family), fear of side-effects and a lack of knowledge. Despite these barriers, many women in the study indicated that they were open to adopting a modern family planning method in the future. These findings imply that programming must address mutual comprehension and decision-making among rural men and women alike in order to trigger positive changes in behaviour and perceptions relating to contraceptive use.

  5. FISCAL DECENTRALIZATION IN THE DRC: EVIDENCE OFREVENUE ASSIGNMENT

    Directory of Open Access Journals (Sweden)

    Angelita Kithatu-Kiwekete

    2017-07-01

    Full Text Available The rationalefor central government to devolve resources for service provisionhas been debated in decentralization literature. Decentralization enhancesdemocracy,encouragesparticipation in local development initiativesandpromotes local political accountability.This discourse has been complemented bythe implementation of fiscal decentralization to increase the ability of sub-nationalgovernment in financing municipal service delivery. Fiscal decentralization hasoften been adopted by African statessince the onset ofthe New PublicManagement erain an effortto improvethe standard ofgovernance. The concernis that African states have taken minimal steps to adopt fiscal devolution thatpromotes revenue assignment which in turn limits sub-nationalgovernments’ability to generate own source revenues.This article examines the revenue assignment function of fiscal decentralization inthe Democratic Republic of Congo(DRCinthelight of decentralizationconcerns that have been raised by civil society, as the country charts its course todemocracy. The article is a desktop study that will consider documents andpoliciesin theDRCon thenational, provincialand locallevel as far asstaterevenue sourcesare concerned. Revenue assignment should enable DRC’sprovinces and local authoritiestogeneratesignificantrevenueindependently.However, post-conflict reconstruction and development efforts in the Great Lakesregion and in the DRC have largely isolated decentralization which wouldotherwise entrench local fiscalautonomy infinancing for local services anddevelopment. The article concludes that revenue generation for local authoritiesandtheprovinces in the DRC is still very centralised by the national government.Thearticleproposes policy recommendations that will be useful for the country toensurethatdecentralization effortsinclude fiscal devolution toenhance thefinancing for local development initiatives.

  6. Incidents of chemical reactions in cell equipment

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, N.M.; Barlow, C.R. [Uranium Enrichment Organization, Oak Ridge, TN (United States)

    1991-12-31

    Strongly exothermic reactions can occur between equipment structural components and process gases under certain accident conditions in the diffusion enrichment cascades. This paper describes the conditions required for initiation of these reactions, and describes the range of such reactions experienced over nearly 50 years of equipment operation in the US uranium enrichment program. Factors are cited which can promote or limit the destructive extent of these reactions, and process operations are described which are designed to control the reactions to minimize equipment damage, downtime, and the possibility of material releases.

  7. The application of inductively coupled plasma dynamic reaction cell mass spectrometry for measurement of selenium isotopes, isotope ratios and chromatographic detection of selenoamino acids

    DEFF Research Database (Denmark)

    Sloth, Jens Jørgen; Larsen, Erik Huusfeldt

    2000-01-01

    orders of magnitude by using methane as reactive cell gas in the DRC. By using 3% v/v methanol in water for carbon-enhanced ionisation of selenium, the sensitivity of Se-80 was 10(4) counts s(-1) per ng ml(-1) of selenium, and the estimated limit of detection was 6 pg ml(-1). The precision of the isotope...

  8. Mast cell subsets and neuropeptides in leprosy reactions

    Directory of Open Access Journals (Sweden)

    Antunes Sérgio Luiz Gomes

    2003-01-01

    Full Text Available The immunohistochemical identification of neuropeptides (calcitonin gene-related peptide, vasoactive intestinal polypeptide, substance P, alpha-melanocyte stimulating hormone and gamma-melanocyte stimulating hormone quantification of mast cells and their subsets (tryptase/chymase-immunoreactive mast cells = TCMC and tryptase-immunoreactive mast cells = TMC were determined in biopsies of six patients with leprosy reactions (three patients with type I reaction and three with type II. Biopsies were compared with those taken from the same body site in the remission stage of the same patient. We found a relative increase of TMC in the inflammatory infiltrate of the reactional biopsies compared to the post-reactional biopsy. Also, the total number of mast cells and the TMC/TCMC ratio in the inflammatory infiltrate was significantly higher than in the intervening dermis of the biopsies of both periods. No significant difference was found regarding neuroptide expression in the reactional and post-reactional biopsies. The relative increase of TMC in the reactional infiltrates could implicate this mast cell subset in the reported increase of the immune response in leprosy reactions.

  9. Leukemoid reaction associated with transitional cell carcinoma: A ...

    African Journals Online (AJOL)

    Leukemoid reaction associated with transitional cell carcinoma: A case report ... Nigerian Journal of Clinical Practice ... At 3 months later, patient was admitted to our 21 22 hospital with the complaints of the left leg edema, diagnosed as pelvic

  10. Regulation of Germinal Center Reactions by B and T Cells

    Directory of Open Access Journals (Sweden)

    Yeonseok Chung

    2013-10-01

    Full Text Available Break of B cell tolerance to self-antigens results in the development of autoantibodies and, thus, leads to autoimmunity. How B cell tolerance is maintained during active germinal center (GC reactions is yet to be fully understood. Recent advances revealed several subsets of T cells and B cells that can positively or negatively regulate GC B cell responses in vivo. IL-21-producing CXCR5+ CD4+ T cells comprise a distinct lineage of helper T cells—termed follicular helper T cells (TFH—that can provide help for the development of GC reactions where somatic hypermutation and affinity maturation take place. Although the function of TFH cells is beneficial in generating high affinity antibodies against infectious agents, aberrant activation of TFH cell or B cell to self-antigens results in autoimmunity. At least three subsets of immune cells have been proposed as regulatory cells that can limit such antibody-mediated autoimmunity, including follicular regulatory T cells (TFR, Qa-1 restricted CD8+ regulatory T cells (CD8+TREG, and regulatory B cells (BREG. In this review, we will discuss our current understanding of GC B cell regulation with specific emphasis on the newly identified immune cell subsets involved in this process.

  11. Quantification of DNA repair capacity (DRC) in peripheral blood lymphocytes of individuals from natural high background radiation areas of Kerala, India

    International Nuclear Information System (INIS)

    Vivek Kumar, P.R.; Seshadri, M.

    2011-01-01

    Human populations residing in the coastal areas of Kerala from Neendakara in south to Purakkad in north receive high level natural background radiation primarily due to the presence of thorium ( 232 Th) in the monazite containing beach sand. This provides a unique opportunity to investigate the health effects of natural high level radiation on humans. Earlier studies from our laboratory in newborns for incidence of congenital malformations, structural and numerical chromosome aberrations failed to show any significant health or biological effects due to high level natural radiation exposure. The current study used alkaline single cell gel electrophoresis (comet) assay due to its sensitivity, speed, flexibility and low cost. Biological effects of low level natural radiation was studied by assessing individual's DNA Repair Capacity (DRC), which is essential for maintaining the genome integrity. DNA damage was estimated in terms of DNA strand breaks per million base pairs (SB/106 bp). In our earlier study using comet assay, DNA SBs increased with age in subjects from normal background radiation area (NBRA). However, significant inverse correlation was observed in subjects from high background radiation area (HBRA). Further, spontaneous DNA SBs in elderly subjects (? 41 years) from HBRA was significantly lower compared to the subjects from NBRA. The present study was carried out in 90 healthy adult male subjects of which, 63 subjects belonged to HBRA and 27 subjects from NBRA. The annual effective dose in HBRA subjects was 5.87 ± 4.17 mSv year-1 (Mean ± S.D., range 1.07-17.41) and in NBRA subjects was ? 1mSv year-1. Peripheral blood lymphocytes from these individuals were irradiated with 4Gy of 60 Co gamma rays (1.4Gy/minute, Low dose irradiator 2000, BRIT, India) and DNA repair was assessed at 30 minutes. As the results were not normally distributed, the data were log transformed to normalize variance. Regression analysis was carried out to determine the relative

  12. Hemoglobin redox reactions and red blood cell aging.

    Science.gov (United States)

    Rifkind, Joseph M; Nagababu, Enika

    2013-06-10

    The physiological mechanism(s) for recognition and removal of red blood cells (RBCs) from circulation after 120 days of its lifespan is not fully understood. Many of the processes thought to be associated with the removal of RBCs involve oxidative stress. We have focused on hemoglobin (Hb) redox reactions, which is the major source of RBC oxidative stress. The importance of Hb redox reactions have been shown to originate in large parts from the continuous slow autoxidation of Hb producing superoxide and its dramatic increase under hypoxic conditions. In addition, oxidative stress has been shown to be associated with redox reactions that originate from Hb reactions with nitrite and nitric oxide (NO) and the resultant formation of highly toxic peroxynitrite when NO reacts with superoxide released during Hb autoxidation. The interaction of Hb, particularly under hypoxic conditions with band 3 of the RBC membrane is critical for the generating the RBC membrane changes that trigger the removal of cells from circulation. These changes include exposure of antigenic sites, increased calcium leakage into the RBC, and the resultant leakage of potassium out of the RBC causing cell shrinkage and impaired deformability. The need to understand the oxidative damage to specific membrane proteins that result from redox reactions occurring when Hb is bound to the membrane. Proteomic studies that can pinpoint the specific proteins damaged under different conditions will help elucidate the cellular aging processes that result in cells being removed from circulation.

  13. Contributions of cell growth and biochemical reactions to nongenetic variability of cells.

    NARCIS (Netherlands)

    Schwabe, A.; Bruggeman, F.J.

    2014-01-01

    Cell-to-cell variability in the molecular composition of isogenic, steady-state growing cells arises spontaneously from the inherent stochasticity of intracellular biochemical reactions and cell growth. Here, we present a general decomposition of the total variance in the copy number per cell of a

  14. Local cell-mediated immune reactions in cancer patients

    International Nuclear Information System (INIS)

    Bilynskij, B.T.; Vasil'ev, N.V.; Volod'ko, N.A.; Akademiya Meditsinskikh Nauk SSSR, Tomsk. Onkologicheskij Nauchnyj Tsentr)

    1988-01-01

    The analysis of 178 cases of stage I-II breast cancer showed morphological features of local cell-mediated immune reactions to be of limited prognostic value. A comparative evaluation of some characteristics of cell surface receptors, such as ability to spontaneous rosette formation with sheep erythrocytes and sensitivty to theophylline, was carried out in lymphocyte samples obtained from tumor tissue and peripheral blood of 76 cancer patients subjected to preoperative radiotherapy. The said parameters were studied in breast cancer patients of rosette-forming cell reaction to theophylline were identified, the incidence of some of them being determined by the presence or absence of regional metastases. The level and functional activity of surface receptors of tumor mononuclear cells proved to influence prognosis

  15. Sexual violence in the protracted conflict of DRC programming for rape survivors in South Kivu

    Directory of Open Access Journals (Sweden)

    Schmitz K Peter

    2009-03-01

    Full Text Available Abstract Background Despite international acknowledgement of the linkages between sexual violence and conflict, reliable data on its prevalence, the circumstances, characteristics of perpetrators, and physical or mental health impacts is rare. Among the conflicts that have been associated with widespread sexual violence has been the one in the Democratic Republic of the Congo (DRC. Methods From 2003 till to date Malteser International has run a medico-social support programme for rape survivors in South Kivu province, DRC. In the context of this programme, a host of data was collected. We present these data and discuss the findings within the frame of available literature. Results Malteser International registered 20,517 female rape survivors in the three year period 2005–2007. Women of all ages have been targeted by sexual violence and only few of those – and many of them only after several years – sought medical care and psychological help. Sexual violence in the DRC frequently led to social, especially familial, exclusion. Members of military and paramilitary groups were identified as the main perpetrators of sexual violence. Conclusion We have documented that in the DRC conflict sexual violence has been – and continues to be – highly prevalent in a wide area in the East of the country. Humanitarian programming in this field is challenging due to the multiple needs of rape survivors. The easily accessible, integrated medical and psycho-social care that the programme offered apparently responded to the needs of many rape survivors in this area.

  16. Sexual violence in the protracted conflict of DRC programming for rape survivors in South Kivu

    Science.gov (United States)

    Steiner, Birthe; Benner, Marie T; Sondorp, Egbert; Schmitz, K Peter; Mesmer, Ursula; Rosenberger, Sandrine

    2009-01-01

    Background Despite international acknowledgement of the linkages between sexual violence and conflict, reliable data on its prevalence, the circumstances, characteristics of perpetrators, and physical or mental health impacts is rare. Among the conflicts that have been associated with widespread sexual violence has been the one in the Democratic Republic of the Congo (DRC). Methods From 2003 till to date Malteser International has run a medico-social support programme for rape survivors in South Kivu province, DRC. In the context of this programme, a host of data was collected. We present these data and discuss the findings within the frame of available literature. Results Malteser International registered 20,517 female rape survivors in the three year period 2005–2007. Women of all ages have been targeted by sexual violence and only few of those – and many of them only after several years – sought medical care and psychological help. Sexual violence in the DRC frequently led to social, especially familial, exclusion. Members of military and paramilitary groups were identified as the main perpetrators of sexual violence. Conclusion We have documented that in the DRC conflict sexual violence has been – and continues to be – highly prevalent in a wide area in the East of the country. Humanitarian programming in this field is challenging due to the multiple needs of rape survivors. The easily accessible, integrated medical and psycho-social care that the programme offered apparently responded to the needs of many rape survivors in this area. PMID:19284879

  17. Agrobacterium -induced hypersensitive necrotic reaction in plant cells

    African Journals Online (AJOL)

    High necrosis and poor survival rate of target plant tissues are some of the major factors that affect the efficiency of Agrobacterium-mediated T-DNA transfer into plant cells. These factors may be the result of, or linked to, hypersensitive defense reaction in plants to Agrobacterium infection, which may involve the recognition ...

  18. Studying reaction products in a lithium thionyl chloride cell

    International Nuclear Information System (INIS)

    Vol'fkovich, Yu.M.; Sosenkin, V.E.; Nikol'skaya, N.F.; Blinov, I.A.

    1999-01-01

    Change in the mass, volume and chemical composition of reaction insoluble products (RIP) formed in the course of discharge of thionyl chloride lithium cells under different conditions has been studied by the methods of gravimetry, volumetry and element analysis. It has been ascertained that the measured volume and mass of RIP essentially (by a factor of 1.1-1.8) exceed the calculated values, proceeding from the reaction stoichiometry. Besides lithium chloride and sulfur during discharge additional RIP is formed as LiAlCl 4 · SOCl 2 solvate, its share increasing with temperature decrease, increase in current density and electrolyte concentration [ru

  19. Lithium cell reactions. Interim report, December 1981-May 1983. [Lithium-thionyl chloride cell

    Energy Technology Data Exchange (ETDEWEB)

    Clark, W.; Dampier, F.; Lombardi, A.; Cole, T.

    1983-12-01

    This report presents the results of a program that investigated reactions occurring in lithium-thionyl chloride cells for a range of specified test conditions and also performed detailed analyses for impurities present in cell components, assessed the impact of each impurity on cell performance and safety, and recommended concentration limits for detrimental impurities. Methods used in the program included linear sweep voltammetry, constant current coulometry, infrared spectroscopy, chemical analysis of the reagents and cell components, and cell discharge tests.

  20. Electrocatalysis of fuel cell reactions: Investigation of alternate electrolytes

    Science.gov (United States)

    Chin, D. T.; Hsueh, K. L.; Chang, H. H.

    1984-01-01

    Oxygen reduction and transport properties of the electrolyte in the phosphoric acid fuel cell are studied. The areas covered were: (1) development of a theoretical expression for the rotating ring disk electrode technique; (2) determination of the intermediate reaction rate constants for oxygen reduction on platinum in phosphoric acid electrolyte; (3) determination of oxygen reduction mechanism in trifluoreomethanesulfonic acid (TFMSA) which was considered as an alternate electrolyte for the acid fuel cells; and (4) the measurement of transport properties of the phosphoric acid electrolyte at high concentrations and temperatures.

  1. Determination of As and Se in crude oil diluted in xylene by inductively coupled plasma mass spectrometry using a dynamic reaction cell for interference correction on {sup 80}Se

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, Fernanda Inda de [Departamento de Quimica, Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), Rua Marques de Sao Vicente 225, 22451-900 Rio de Janeiro, RJ (Brazil); Duyck, Christiane B., E-mail: cbduyck@vm.uff.br [Departamento de Quimica, Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), Rua Marques de Sao Vicente 225, 22451-900 Rio de Janeiro, RJ (Brazil); Departamento de Quimica, Universidade Federal Fluminense (UFF), Outeiro Sao Joao Batista s/n, Centro, 24020-150, Niteroi, RJ (Brazil); Fonseca, Teresa Cristina O. [Centro de Pesquisas Leopoldo A. Miguez de Mello da Petrobras (CENPES) (Brazil); Saint' Pierre, Tatiana D. [Departamento de Quimica, Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), Rua Marques de Sao Vicente 225, 22451-900 Rio de Janeiro, RJ (Brazil)

    2012-05-15

    Arsenic and selenium can be found in crude oils and represent an important source of pollution when released to the environment during any stage of extraction or refinery. These elements present low sensitivity in the direct determination by inductively coupled plasma mass spectrometry (ICP-MS), due to their high ionization potential, and are also prone to spectral interferences. Hydride generation (HG) can be alternatively employed for the separation of these analytes from the sample matrix and introduction into the instrument. However, the required sample preparation usually increases the analysis time. In this work, a method was developed for the determination of As and Se in crude oil by ICP-MS, after sample dilution in xylene. The use of a dynamic reaction cell (DRC) allowed for the overcoming of Ar{sub 2}{sup +} interference on {sup 80}Se, but was not necessary for As, since interference on m/z 75 was not observed. The optimized operational conditions for {sup 75}As and {sup 80}Se were: 1350 W of RF power, 0.4 L min{sup -1} of Ar nebulizer and 0.7 L min{sup -1} of Ar auxiliary flow rates. The DRC conditions for {sup 80}Se were 0.5 L min{sup -1} of methane and rejection parameter q (Rpq) of 0.2. The analyses were carried out by analyte addition and the limits of detection (LOD) were 0.04 {mu}g kg{sup -1} for As and 0.1 {mu}g kg{sup -1} for Se. The accuracy was verified by the analysis of residual fuel oil certified material, with agreement at a 95% confidence level. Nine Brazilian crude oil samples were analyzed and the results compared to those obtained by hydride generation ICP-MS. In this case, samples were decomposed with nitric acid in a digester block, the analytes pre-reduced with HCl 6 mol L{sup -1} and the determination carried out by external calibration. Although better instrumental LODs were obtained by HG (0.002 {mu}g kg{sup -1} of As and 0.04 {mu}g kg{sup -1} of Se), the direct determination of As and Se in crude oil diluted in xylene by DRC

  2. Development of a method based on inductively coupled plasma-dynamic reaction cell-mass spectrometry for the simultaneous determination of phosphorus, calcium and strontium in bone and dental tissue

    International Nuclear Information System (INIS)

    De Muynck, David; Vanhaecke, Frank

    2009-01-01

    A method, based on the use of a quadrupole-based inductively coupled plasma-mass spectrometry instrument equipped with a quadrupole-based collision/reaction cell (dynamic reaction cell, DRC), was developed for the simultaneous determination of phosphorus, calcium and strontium in bone and dental (enamel and dentine) tissue. The use of NH 3 , introduced at a gas flow rate of 0.8 mL min -1 in the dynamic reaction cell, combined with a rejection parameter q (RPq) setting of 0.65, allows interference-free determination of calcium via its low-abundant isotopes 42 Ca, 43 Ca and 44 Ca, and of strontium via its isotopes 86 Sr and 88 Sr that are freed from overlap due to the occurrence of ArCa + and/or Ca 2 + ions. Also the determination of phosphorus ( 31 P, mono-isotopic) was shown to be achievable using the same dynamic reaction cell operating conditions. The bone certified reference materials NIST SRM 1400 Bone Ash and NIST SRM 1486 Bone Meal were used for validation of the measurement protocol that was shown capable of providing accurate and reproducible results. Detection limits of P, Ca and Sr in dental tissue digests were established as 3 μg L -1 for P, 2 μg L -1 for Ca and 0.2 μg L -1 for Sr. This method can be used to simultaneously (i) evaluate the impact of diagenesis on the elemental and isotopic composition of buried skeletal tissue via its Ca/P ratio and (ii) determine its Sr concentration. The measurement protocol was demonstrated as fit-for-purpose by the analysis of a set of teeth of archaeological interest for their Ca/P ratio and Sr concentration.

  3. Humanitarian presence and urban development: new opportunities and contrasts in Goma, DRC.

    Science.gov (United States)

    Büscher, Karen; Vlassenroot, Koen

    2010-04-01

    This paper examines the impact of the presence of international humanitarian organisations on local urban transformation processes in the city of Goma, Democratic Republic of the Congo (DRC). Rather than evaluating the direct effects of humanitarian interventions and strategies, it focuses on the indirect but profound effects of the presence of this 'humanitarian sector'. It argues that the international humanitarian presence became a significant factor in the recent shaping and reshaping of the city's profile and has reinforced competition over the urban political and socioeconomic space. The paper evaluates the direct and indirect impact of the international humanitarian presence on the local urban economy and the larger political economy of war in eastern DRC. It analyses how this presence has reinforced processes of spatial reconfiguration, how it has influenced urban planning, and how it has affected dynamics of gentrification and marginalisation on the urban spatial level.

  4. The Clones of 'Mr Kurtz': Violence, War and Plunder in the DRC ...

    African Journals Online (AJOL)

    The Clones of 'Mr Kurtz': Violence, War and Plunder in the DRC. Mwesiga Baregu. Abstract. (Af. J. Political Science: 2002 7(2): 11-38). Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/ajps.v7i2.27329 · AJOL African Journals Online. HOW TO ...

  5. Civilian Protection in the Eastern DRC: Evaluation of the MONUSCO Peacekeeping Operation

    Science.gov (United States)

    2012-03-01

    Richard Shelly Hartigan, Civilian Victims in War: A Political History (Chicago: Precedent Publishers, 2010), 5–6. 32 Ibid., 7. 33 Martha Finnemore...in the DRC, and also because it casts light on the convoluted reality of violence in the eastern Congo. That is, it presents a visceral example of how...be Anonymous,’” National Public Radio World News, 6 April 2011. Hartigan, Richard Shelly . Civilian Victims in War: A Political History. Chicago

  6. Bendamustine and rituximab (BR) versus dexamethasone, rituximab, and cyclophosphamide (DRC) in patients with Waldenström macroglobulinemia.

    Science.gov (United States)

    Paludo, Jonas; Abeykoon, Jithma P; Shreders, Amanda; Ansell, Stephen M; Kumar, Shaji; Ailawadhi, Sikander; King, Rebecca L; Koehler, Amber B; Reeder, Craig B; Buadi, Francis K; Dispenzieri, Angela; Lacy, Martha Q; Dingli, David; Witzig, Thomas E; Go, Ronald S; Gonsalves, Wilson I; Kourelis, Taxiarchis; Warsame, Rahma; Leung, Nelson; Habermann, Thomas M; Hayman, Suzanne; Lin, Yi; Kyle, Robert A; Rajkumar, S Vincent; Gertz, Morie A; Kapoor, Prashant

    2018-04-03

    The treatment approaches for Waldenstrom macroglobulinemia (WM) are largely based upon information from single-arm phase II trials, without comparative data. We compared the efficacy of two commonly used regimens in routine practice (bendamustine-rituximab (BR) and dexamethasone, rituximab plus cyclophosphamide (DRC)) and evaluated their activity with respect to the patients' MYD88 L265P mutation status. Of 160 consecutive patients, 60 received BR (43 with relapsed/refractory WM) and 100 received DRC (50 had relapsed/refractory WM). In the treatment-naïve setting, overall response rate (ORR) was 93% with BR versus 96% with DRC (p = 0.55). Two-year progression-free survival (PFS) with BR and DRC was 88 and 61%, respectively (p = 0.07). In salvage setting, ORR was 95% with BR versus 87% with DRC, p = 0.45; median PFS with BR was 58 versus 32 months with DRC (2-year PFS was 66 versus 53%; p = 0.08). Median disease-specific survival was not reached with BR versus 166 months with DRC (p = 0.51). The time-to-event endpoints and depth of response were independent of the MYD88 mutation status. Grade ≥ 3 adverse events of both regimens were comparable. A trend for longer PFS was observed with BR although the regimens have comparable toxicities. The activity of BR and DRC appears to be unaffected by patients' MYD88 mutation status.

  7. Low Energy Reaction cell for advanced space power applications

    International Nuclear Information System (INIS)

    Miley, George H.; Rice, Eric

    2001-01-01

    Power units using Low Energy Reactions (LENRs) are under study as a radical new approach to power units that could potentially replace nuclear and chemical power sources for a number of space applications. These cells employ thin metallic films (order of 500 deg., using variously Ni, Pd and Ti) as cathodes with various electrolytes such as 0.5-1 molar lithium sulfate in light water. Power densities exceeding 10 W/cm3 in the thin-films have been achieved. An ultimate goal is to incorporate this thin-film technology into a 'tightly packed' cell design where the film material occupies ∼20% of the total cell volume. If this is achieved, overall power densities of ∼20 W/cm3 appear feasible, opening the way to a number of potential applications ranging from distributed power units in spacecraft to advanced propulsion

  8. Study of charge transfer reactions in a microbial fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Martin, E.; Savadogo, O. [Ecole Polytechnique, Montreal, PQ (Canada). Dept. de Genie Chimique; National Research Council of Canada, Montreal, PQ (Canada). Biotechnology Research Inst.; Tartakovsky, B. [National Research Council of Canada, Montreal, PQ (Canada). Biotechnology Research Inst.

    2008-07-01

    Electron transfer reactions in a microbial fuel cell (MFC) were evaluated. The MFC was inoculated with anaerobic mesophilic sludge and operated with carbon felt, carbon cloth, and platinum (Pt) coated carbon cloth. The MFC was then fed with either acetate or glucose as a source of fuel and operated at a temperature of 25 degrees C and a pH of 7. Scanning electron microscopy (SEM) micrographs demonstrated that the micro-organisms colonized the anodes. Cyclic voltammetry and polarization tests were conducted using different fractions of the anodophilic biofilm in order to determine charge transfer routes. The study characterized the electron transfer mechanisms used by the exoelectrogenic micro-organisms to produce electricity. It was concluded that further research is needed to characterize reaction transfer routes. 2 refs., 1 fig.

  9. RFQ Reaction Cells for AMS: Developments and Applications

    Directory of Open Access Journals (Sweden)

    Kieser William E.

    2013-12-01

    Full Text Available The use of anion-gas interactions in Radiofrequency Quadrupole (RFQ ion guide reaction cells has been shown to be very effective in the elimination of a number of atomic and molecular isobars which have caused difficulties for Accelerator Mass Spectrometry (AMS measurements [1,2]. This presentation begins with a review of the early work leading to the use of ion-gas reactions and continues with a discussion the recent measurements of the efficacy of this technique, some of which involve fluoride molecular anions. However, the transformation of the equipment used for these proof-of-principle measurements into a system suitable for routine analysis has required attention to aspects of the ion beam transport and gas handling subsystems. For example, the cross sections of the ion-gas reactions, involving both the analyte ion as well as the isobar, are critically dependent on the ion energy which has to be reduced from the ion source energy, usually between 20 and 80 keV, to energies typically in the range of several eV, a task complicated by the energy spread and divergence of beams from AMS sputter sources. With simulations using SIMION 8.1 [3] and tests of promising configurations in a laboratory system, principles for the design of the retarder optics have been developed. These are discussed, along with their planned implementation in a next generation analytical system.

  10. Recent development of active nanoparticle catalysts for fuel cell reactions

    Energy Technology Data Exchange (ETDEWEB)

    Mazumder, Vismadeb; Lee, Youngmin; Sun, Shouheng [Department of Chemistry Brown University Providence, RI (United States)

    2010-04-23

    This review focuses on the recent advances in the synthesis of nanoparticle (NP) catalysts of Pt-, Pd- and Au-based NPs as well as composite NPs. First, new developments in the synthesis of single-component Pt, Pd and Au NPs are summarized. Then the chemistry used to make alloy and composite NP catalysts aiming to enhance their activity and durability for fuel cell reactions is outlined. The review next introduces the exciting new research push in developing CoN/C and FeN/C as non-Pt catalysts. Examples of size-, shape- and composition-dependent catalyses for oxygen reduction at cathode and formic acid oxidation at anode are highlighted to illustrate the potentials of the newly developed NP catalysts for fuel cell applications. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  11. Claustral single cell reactions to tooth pulp stimulation in cats.

    Science.gov (United States)

    Jastreboff, P; Sikora, M; Frydrychowski, A; Słoniewski, P

    1983-01-01

    Single unit activity in the central region of the claustrum, evoked by electrical stimulation of tooth pulp or paws was studied on cats under chloralose anesthesia. The majority of cells responded in similar manner to stimulation of tooth pulp or paws, but there were cells with clear preference to a given type of stimulation. Latencies of reactions evoked by tooth pulp stimulation were significantly shorter than those for limb stimulation. In the former case latencies as short as 8 rns were observed. It is postulated that the central region of the claustrum receives a projection from the tooth pulp, and that in those cases with very short latency the projection is direct and does not involve the cerebral cortex.

  12. Reaction and Aggregation Dynamics of Cell Surface Receptors

    Science.gov (United States)

    Wang, Michelle Dong

    This dissertation is composed of both theoretical and experimental studies of cell surface receptor reaction and aggregation. Project I studies the reaction rate enhancement due to surface diffusion of a bulk dissolved ligand with its membrane embedded target, using numerical calculations. The results show that the reaction rate enhancement is determined by ligand surface adsorption and desorption kinetic rates, surface and bulk diffusion coefficients, and geometry. In particular, we demonstrate that the ligand surface adsorption and desorption kinetic rates, rather than their ratio (the equilibrium constant), are important in rate enhancement. The second and third projects are studies of acetylcholine receptor clusters on cultured rat myotubes using fluorescence techniques after labeling the receptors with tetramethylrhodamine -alpha-bungarotoxin. The second project studies when and where the clusters form by making time-lapse movies. The movies are made from overlay of the pseudocolored total internal reflection fluorescence (TIRF) images of the cluster, and the schlieren images of the cell cultures. These movies are the first movies made using TIRF, and they clearly show the cluster formation from the myoblast fusion, the first appearance of clusters, and the eventual disappearance of clusters. The third project studies the fine structural features of individual clusters observed under TIRF. The features were characterized with six parameters by developing a novel fluorescence technique: spatial fluorescence autocorrelation. These parameters were then used to study the feature variations with age, and with treatments of drugs (oligomycin and carbachol). The results show little variation with age. However, drug treatment induced significant changes in some parameters. These changes were different for oligomycin and carbachol, which indicates that the two drugs may eliminate clusters through different mechanisms.

  13. Hierarchical feedback modules and reaction hubs in cell signaling networks.

    Science.gov (United States)

    Xu, Jianfeng; Lan, Yueheng

    2015-01-01

    Despite much effort, identification of modular structures and study of their organizing and functional roles remain a formidable challenge in molecular systems biology, which, however, is essential in reaching a systematic understanding of large-scale cell regulation networks and hence gaining capacity of exerting effective interference to cell activity. Combining graph theoretic methods with available dynamics information, we successfully retrieved multiple feedback modules of three important signaling networks. These feedbacks are structurally arranged in a hierarchical way and dynamically produce layered temporal profiles of output signals. We found that global and local feedbacks act in very different ways and on distinct features of the information flow conveyed by signal transduction but work highly coordinately to implement specific biological functions. The redundancy embodied with multiple signal-relaying channels and feedback controls bestow great robustness and the reaction hubs seated at junctions of different paths announce their paramount importance through exquisite parameter management. The current investigation reveals intriguing general features of the organization of cell signaling networks and their relevance to biological function, which may find interesting applications in analysis, design and control of bio-networks.

  14. Hierarchical feedback modules and reaction hubs in cell signaling networks.

    Directory of Open Access Journals (Sweden)

    Jianfeng Xu

    Full Text Available Despite much effort, identification of modular structures and study of their organizing and functional roles remain a formidable challenge in molecular systems biology, which, however, is essential in reaching a systematic understanding of large-scale cell regulation networks and hence gaining capacity of exerting effective interference to cell activity. Combining graph theoretic methods with available dynamics information, we successfully retrieved multiple feedback modules of three important signaling networks. These feedbacks are structurally arranged in a hierarchical way and dynamically produce layered temporal profiles of output signals. We found that global and local feedbacks act in very different ways and on distinct features of the information flow conveyed by signal transduction but work highly coordinately to implement specific biological functions. The redundancy embodied with multiple signal-relaying channels and feedback controls bestow great robustness and the reaction hubs seated at junctions of different paths announce their paramount importance through exquisite parameter management. The current investigation reveals intriguing general features of the organization of cell signaling networks and their relevance to biological function, which may find interesting applications in analysis, design and control of bio-networks.

  15. Hierarchical Feedback Modules and Reaction Hubs in Cell Signaling Networks

    Science.gov (United States)

    Xu, Jianfeng; Lan, Yueheng

    2015-01-01

    Despite much effort, identification of modular structures and study of their organizing and functional roles remain a formidable challenge in molecular systems biology, which, however, is essential in reaching a systematic understanding of large-scale cell regulation networks and hence gaining capacity of exerting effective interference to cell activity. Combining graph theoretic methods with available dynamics information, we successfully retrieved multiple feedback modules of three important signaling networks. These feedbacks are structurally arranged in a hierarchical way and dynamically produce layered temporal profiles of output signals. We found that global and local feedbacks act in very different ways and on distinct features of the information flow conveyed by signal transduction but work highly coordinately to implement specific biological functions. The redundancy embodied with multiple signal-relaying channels and feedback controls bestow great robustness and the reaction hubs seated at junctions of different paths announce their paramount importance through exquisite parameter management. The current investigation reveals intriguing general features of the organization of cell signaling networks and their relevance to biological function, which may find interesting applications in analysis, design and control of bio-networks. PMID:25951347

  16. MONITORING REACTIONS IN ALKALINE DIRECT ETHANOL FUEL CELLS ASSEMBLED WITH NON-PT-CATALYST

    OpenAIRE

    Gülzow, Erich; Beyer, Monique; Friedrich, K. Andreas; Pengel, Stefanie; Fischer, Peter; Bettermann, Hans

    2011-01-01

    This contribution shows how Raman spectroscopy can be used to pursue chemical reactions within fuel cells. For this, the oxidation of ethanol occurring in an alkaline direct ethanolic fuel cell was investigated. The analysis of a sequence of Raman spectra recorded during the reaction shows that ethanol was solely oxidized to acetate in a unique reaction.

  17. Functional changes of dendritic cells in hypersensivity reactions to amoxicillin

    Directory of Open Access Journals (Sweden)

    C.M.F. Lima

    2010-10-01

    Full Text Available A better understanding of dendritic cell (DC involvement in responses to haptenic drugs is needed, because it represents a possible approach to the development of an in vitro test, which could identify patients prone to drug allergies. There are two main DC subsets: plasmacytoid DC (pDC and myeloid DC (mDC. β-lactams form hapten-carrier conjugates and may provide a suitable model to study DC behavior in drug allergy reactions. It has been demonstrated that drugs interact differently with DC in drug allergic and non-allergic patients, but there are no studies regarding these subsets. Our aim was to assess the functional changes of mDC and pDC harvested from an amoxicillin-hypersensitive 32-year-old woman who experienced a severe maculopapular exanthema as reflected in interleukin-6 (IL-6 production after stimulation with this drug and penicillin. We also aim to demonstrate, for the first time, the feasibility of this method for dendritic cell isolation followed by in vitro stimulation for studies of drug allergy physiopathology. DC were harvested using a double Percoll density gradient, which generates a basophil-depleted cell (BDC suspension. Further, pDC were isolated by blood DC antigen 4-positive magnetic selection and gravity filtration through magnetized columns. After stimulation with amoxicillin, penicillin and positive and negative controls, IL-6 production was measured by ELISA. A positive dose-response curve for IL-6 after stimulation with amoxicillin and penicillin was observed for pDC, but not for mDC or BDC suspension. These preliminary results demonstrate the feasibility of this methodology to expand the knowledge of the effect of dendritic cell activation by drug allergens.

  18. Compact reaction cell for homogenizing and down-blending highly enriched uranium metal

    Science.gov (United States)

    McLean, W. II; Miller, P.E.; Horton, J.A.

    1995-05-02

    The invention is a specialized reaction cell for converting uranium metal to uranium oxide. In a preferred form, the reaction cell comprises a reaction chamber with increasing diameter along its length (e.g. a cylindrical chamber having a diameter of about 2 inches in a lower portion and having a diameter of from about 4 to about 12 inches in an upper portion). Such dimensions are important to achieve the necessary conversion while at the same time affording criticality control and transportability of the cell and product. The reaction chamber further comprises an upper port and a lower port, the lower port allowing for the entry of reactant gases into the reaction chamber, the upper port allowing for the exit of gases from the reaction chamber. A diffuser plate is attached to the lower port of the reaction chamber and serves to shape the flow of gas into the reaction chamber. The reaction cell further comprises means for introducing gases into the reaction chamber and a heating means capable of heating the contents of the reaction chamber. The present invention also relates to a method for converting uranium metal to uranium oxide in the reaction cell of the present invention. The invention is useful for down-blending highly enriched uranium metal by the simultaneous conversion of highly enriched uranium metal and natural or depleted uranium metal to uranium oxide within the reaction cell. 4 figs.

  19. Compact reaction cell for homogenizing and down-blanding highly enriched uranium metal

    Science.gov (United States)

    McLean, II, William; Miller, Philip E.; Horton, James A.

    1995-01-01

    The invention is a specialized reaction cell for converting uranium metal to uranium oxide. In a preferred form, the reaction cell comprises a reaction chamber with increasing diameter along its length (e.g. a cylindrical chamber having a diameter of about 2 inches in a lower portion and having a diameter of from about 4 to about 12 inches in an upper portion). Such dimensions are important to achieve the necessary conversion while at the same time affording criticality control and transportability of the cell and product. The reaction chamber further comprises an upper port and a lower port, the lower port allowing for the entry of reactant gasses into the reaction chamber, the upper port allowing for the exit of gasses from the reaction chamber. A diffuser plate is attached to the lower port of the reaction chamber and serves to shape the flow of gas into the reaction chamber. The reaction cell further comprises means for introducing gasses into the reaction chamber and a heating means capable of heating the contents of the reaction chamber. The present invention also relates to a method for converting uranium metal to uranium oxide in the reaction cell of the present invention. The invention is useful for down-blending highly enriched uranium metal by the simultaneous conversion of highly enriched uranium metal and natural or depleted uranium metal to uranium oxide within the reaction cell.

  20. Getting to FP2020: Harnessing the private sector to increase modern contraceptive access and choice in Ethiopia, Nigeria, and DRC.

    Science.gov (United States)

    Riley, Christina; Garfinkel, Danielle; Thanel, Katherine; Esch, Keith; Workalemahu, Endale; Anyanti, Jennifer; Mpanya, Godéfroid; Binanga, Arsène; Pope, Jen; Longfield, Kim; Bertrand, Jane; Shaw, Bryan

    2018-01-01

    An estimated 214 million women have unmet need for family planning in developing regions. Improved utilization of the private sector is key to achieving universal access to a range of safe and effective modern contraceptive methods stipulated by FP2020 and SDG commitments. Until now, a lack of market data has limited understanding of the private sector's role in increasing contraceptive coverage and choice. In 2015, the FPwatch Project conducted representative outlet surveys in Ethiopia, Nigeria, and DRC using a full census approach in selected administrative areas. Every public and private sector outlet with the potential to sell or distribute modern contraceptives was approached. In outlets with modern contraceptives, product audits and provider interviews assessed contraceptive market composition, availability, and price. Excluding general retailers, 96% of potential outlets in Ethiopia, 55% in Nigeria, and 41% in DRC had modern contraceptive methods available. In Ethiopia, 41% of modern contraceptive stocking outlets were in the private sector compared with approximately 80% in Nigeria and DRC where drug shops were dominant. Ninety-five percent of private sector outlets in Ethiopia had modern contraceptive methods available; 37% had three or more methods. In Nigeria and DRC, only 54% and 42% of private sector outlets stocked modern contraceptives with 5% and 4% stocking three or more methods, respectively. High prices in Nigeria and DRC create barriers to consumer access and choice. There is a missed opportunity to provide modern contraception through the private sector, particularly drug shops. Subsidies and interventions, like social marketing and social franchising, could leverage the private sector's role in increasing access to a range of contraceptives. Achieving global FP2020 commitments depends on the expansion of national contraceptive policies that promote greater partnership and cooperation with the private sector and improvement of decisions around

  1. Getting to FP2020: Harnessing the private sector to increase modern contraceptive access and choice in Ethiopia, Nigeria, and DRC.

    Directory of Open Access Journals (Sweden)

    Christina Riley

    Full Text Available An estimated 214 million women have unmet need for family planning in developing regions. Improved utilization of the private sector is key to achieving universal access to a range of safe and effective modern contraceptive methods stipulated by FP2020 and SDG commitments. Until now, a lack of market data has limited understanding of the private sector's role in increasing contraceptive coverage and choice.In 2015, the FPwatch Project conducted representative outlet surveys in Ethiopia, Nigeria, and DRC using a full census approach in selected administrative areas. Every public and private sector outlet with the potential to sell or distribute modern contraceptives was approached. In outlets with modern contraceptives, product audits and provider interviews assessed contraceptive market composition, availability, and price.Excluding general retailers, 96% of potential outlets in Ethiopia, 55% in Nigeria, and 41% in DRC had modern contraceptive methods available. In Ethiopia, 41% of modern contraceptive stocking outlets were in the private sector compared with approximately 80% in Nigeria and DRC where drug shops were dominant. Ninety-five percent of private sector outlets in Ethiopia had modern contraceptive methods available; 37% had three or more methods. In Nigeria and DRC, only 54% and 42% of private sector outlets stocked modern contraceptives with 5% and 4% stocking three or more methods, respectively. High prices in Nigeria and DRC create barriers to consumer access and choice.There is a missed opportunity to provide modern contraception through the private sector, particularly drug shops. Subsidies and interventions, like social marketing and social franchising, could leverage the private sector's role in increasing access to a range of contraceptives. Achieving global FP2020 commitments depends on the expansion of national contraceptive policies that promote greater partnership and cooperation with the private sector and improvement of

  2. Getting to FP2020: Harnessing the private sector to increase modern contraceptive access and choice in Ethiopia, Nigeria, and DRC

    Science.gov (United States)

    Garfinkel, Danielle; Thanel, Katherine; Esch, Keith; Workalemahu, Endale; Anyanti, Jennifer; Mpanya, Godéfroid; Binanga, Arsène; Pope, Jen; Longfield, Kim; Bertrand, Jane; Shaw, Bryan

    2018-01-01

    Background An estimated 214 million women have unmet need for family planning in developing regions. Improved utilization of the private sector is key to achieving universal access to a range of safe and effective modern contraceptive methods stipulated by FP2020 and SDG commitments. Until now, a lack of market data has limited understanding of the private sector’s role in increasing contraceptive coverage and choice. Methods In 2015, the FPwatch Project conducted representative outlet surveys in Ethiopia, Nigeria, and DRC using a full census approach in selected administrative areas. Every public and private sector outlet with the potential to sell or distribute modern contraceptives was approached. In outlets with modern contraceptives, product audits and provider interviews assessed contraceptive market composition, availability, and price. Findings Excluding general retailers, 96% of potential outlets in Ethiopia, 55% in Nigeria, and 41% in DRC had modern contraceptive methods available. In Ethiopia, 41% of modern contraceptive stocking outlets were in the private sector compared with approximately 80% in Nigeria and DRC where drug shops were dominant. Ninety-five percent of private sector outlets in Ethiopia had modern contraceptive methods available; 37% had three or more methods. In Nigeria and DRC, only 54% and 42% of private sector outlets stocked modern contraceptives with 5% and 4% stocking three or more methods, respectively. High prices in Nigeria and DRC create barriers to consumer access and choice. Discussion There is a missed opportunity to provide modern contraception through the private sector, particularly drug shops. Subsidies and interventions, like social marketing and social franchising, could leverage the private sector’s role in increasing access to a range of contraceptives. Achieving global FP2020 commitments depends on the expansion of national contraceptive policies that promote greater partnership and cooperation with the private

  3. Bio-Photoelectrochemical Solar Cells Incorporating Reaction Center and Reaction Center Plus Light Harvesting Complexes

    Science.gov (United States)

    Yaghoubi, Houman

    Harvesting solar energy can potentially be a promising solution to the energy crisis now and in the future. However, material and processing costs continue to be the most important limitations for the commercial devices. A key solution to these problems might lie within the development of bio-hybrid solar cells that seeks to mimic photosynthesis to harvest solar energy and to take advantage of the low material costs, negative carbon footprint, and material abundance. The bio-photoelectrochemical cell technologies exploit biomimetic means of energy conversion by utilizing plant-derived photosystems which can be inexpensive and ultimately the most sustainable alternative. Plants and photosynthetic bacteria harvest light, through special proteins called reaction centers (RCs), with high efficiency and convert it into electrochemical energy. In theory, photosynthetic RCs can be used in a device to harvest solar energy and generate 1.1 V open circuit voltage and ~1 mA cm-2 short circuit photocurrent. Considering the nearly perfect quantum yield of photo-induced charge separation, efficiency of a protein-based solar cell might exceed 20%. In practice, the efficiency of fabricated devices has been limited mainly due to the challenges in the electron transfer between the protein complex and the device electrodes as well as limited light absorption. The overarching goal of this work is to increase the power conversion efficiency in protein-based solar cells by addressing those issues (i.e. electron transfer and light absorption). This work presents several approaches to increase the charge transfer rate between the photosynthetic RC and underlying electrode as well as increasing the light absorption to eventually enhance the external quantum efficiency (EQE) of bio-hybrid solar cells. The first approach is to decrease the electron transfer distance between one of the redox active sites in the RC and the underlying electrode by direct attachment of the of protein complex

  4. Combined effect of x irradiation and cell-mediated immune reaction

    International Nuclear Information System (INIS)

    Song, C.W.; Guertin, D.P.

    1978-01-01

    The combined effect of radiation and cell-mediated immune reaction on tumor cells was investigated in vitro. Mastocytoma P815-X2 cells of DBA mice either were irradiated first and subjected to immune lysis by immune splenic lymphocytes of C57Bl mice, or the tumor cells were subjected to immune reaction first and then irradiated. Cell survival was quantitated by colony formation in soft agar medium. It was observed that cellular immune damage to tumor cells did not influence the response of tumor cells to subsequent radiation. Irradiation of tumor cells first, followed by subjection of the cells to cellular immune reaction, slightly enhanced the death of the tumor cells. It appears that this enhanced death might have resulted from a relative increase in the ratio of the number of cytotoxic immune cells to the number of target tumor cells in the incubation mixture as a consequence of the decrease in the number of viable tumor cells by radiation

  5. Reaction

    African Journals Online (AJOL)

    abp

    19 oct. 2017 ... Reaction to Mohamed Said Nakhli et al. concerning the article: "When the axillary block remains the only alternative in a 5 year old child". .... Bertini L1, Savoia G, De Nicola A, Ivani G, Gravino E, Albani A et al ... 2010;7(2):101-.

  6. Navigating obstacles, opportunities and reforms: women’s lives and livelihoods in artisanal mining communities in eastern DRC

    NARCIS (Netherlands)

    Bashwira Nyenyezi, Marie Rose

    2017-01-01

    For more than two decades, the exploitation and trade of minerals has fuelled armed conflict and fostered a climate of insecurity that has led to the deaths of thousands of people in eastern Democratic Republic of the Congo (DRC) (Katanga, Ituri, Maniema, North and South Kivu). This has been seen

  7. Budget process bottlenecks for immunization financing in the Democratic Republic of the Congo (DRC).

    Science.gov (United States)

    Le Gargasson, Jean-Bernard; Mibulumukini, Benoît; Gessner, Bradford D; Colombini, Anaïs

    2014-02-19

    In Democratic Republic of the Congo (DRC), the availability of domestic resources for the immunization program is limited and relies mostly on external donor support. DRC has introduced a series of reforms to move the country toward performance-based management and program budgets. The objectives of the study were to: (i) describe the budget process norm, (ii) analyze the budget process in practice and associated bottlenecks at each of its phases, and (iii) collect suggestions made by the actors involved to improve the situation. Quantitative and qualitative data were collected through: a review of published and gray literature, and individual interviews. Bottlenecks in the budget process and disbursement of funds for immunization are one of the causes of limited domestic resources for the program. Critical bottlenecks include: excessive use of off-budget procedures; limited human resources and capacity; lack of motivation; interference from ministries with the standard budget process; dependency toward the development partner's disbursements schedule; and lack of budget implementation tracking. Results show that the health sector's mobilization rate was 59% in 2011. For the credit line specific to immunization program activities, the mobilization rate for the national Expanded Program for Immunization (EPI) was 26% in 2011 and 43% for vaccines (2010). The main bottleneck for the EPI budget line (2011) and vaccine budget line (2011) occurs at the authorization phase. Budget process bottlenecks identified in the analysis lead to a low mobilization rate for the immunization program. The bottlenecks identified show that a poor flow of funds causes an insufficient percentage of already allocated resources to reach various health system levels. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Distribution of Electrochemical Reaction Components in Crevice Corrosion Cell

    Directory of Open Access Journals (Sweden)

    Eugeniusz Kurgan

    2004-01-01

    Full Text Available In this paper numerical model of the crevice corrosion is developed. The model considers electrochemical reactions for the iron on the metal electrolyte boundary and chemical reactions which take place in the crevice electrolyte. Mass transfer of ionic species is describes ny Nerst-Plank equation and is solved with the finite element method in two dimensions. On the problem boundary adequate boundary conditions are defined. Distribution of all chemical speciaes, potential and current density in the crevice and on the crevice wall are computed. In mass balance for particular chemical species the speed of the chemical reactions is taken into account. At the end some illustrative example is given.

  9. Note: CO₂-mineral dissolution experiments using a rocking autoclave and a novel titanium reaction cell.

    Science.gov (United States)

    Purser, Gemma; Rochelle, Christopher A; Wallis, Humphrey C; Rosenqvist, Jörgen; Kilpatrick, Andrew D; Yardley, Bruce W D

    2014-08-01

    A novel titanium reaction cell has been constructed for the study of water-rock-CO2 reactions. The reaction cell has been used within a direct-sampling rocking autoclave and offers certain advantages over traditional "flexible gold/titanium cell" approaches. The main advantage is robustness, as flexible cells are prone to rupture on depressurisation during gas-rich experiments. The reaction cell was tested in experiments during an inter-laboratory comparison study, in which mineral kinetic data were determined. The cell performed well during experiments up to 130 °C and 300 bars pressure. The data obtained were similar to those of other laboratories participating in the study, and also to previously published data.

  10. Oral epithelial cell reaction after exposure to Invisalign plastic material.

    Science.gov (United States)

    Premaraj, Thyagaseely; Simet, Samantha; Beatty, Mark; Premaraj, Sundaralingam

    2014-01-01

    Invisalign plastic aligners (Align Technology, Santa Clara, Calif) are used to correct malocclusions. The aligners wrap around the teeth and are in contact with gingival epithelium during treatment. The purpose of this study was to evaluate the cellular responses of oral epithelium exposed to Invisalign plastic in vitro. Oral epithelial cells were exposed to eluate obtained by soaking Invisalign plastic in either saline solution or artificial saliva for 2, 4, and 8 weeks. Cells grown in media containing saline solution or saliva served as controls. Morphologic changes were assessed by light microscopy. The 3-[4, 5-dimethythiazol- 2-yl]-2, 5-diphenyl tetrazolium bromide assay and flow cytometry were used to determine cell viability and membrane integrity, respectively. Cellular adhesion and micromotion of epithelial cells were measured in real time by electrical cell-substrate impedance sensing. Cells exposed to saline-solution eluate appeared rounded, were lifted from the culture plates, and demonstrated significantly increased metabolic inactivity or cell death (P <0.05). Saliva eluates did not induce significant changes in cell viability compared with untreated cells. Flow cytometry and electric cell-substrate impedance sensing showed that cells treated with saline-solution eluate exhibited compromised membrane integrity, and reduced cell-to-cell contact and mobility when compared with saliva-eluate treatment. Exposure to Invisalign plastic caused changes in viability, membrane permeability, and adhesion of epithelial cells in a saline-solution environment. Microleakage and hapten formation secondary to compromised epithelial integrity might lead to isocyanate allergy, which could be systemic or localized to gingiva. However, these results suggest that saliva might offer protection. Copyright © 2014 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  11. Hysteresis in the solid oxide fuel cell cathode reaction

    DEFF Research Database (Denmark)

    Jacobsen, Torben; Zachau-Christiansen, Birgit; Bay, Lasse

    2001-01-01

    The oxygen electrode reaction at the Pt/yttria-stabilised zirconia (YSZ) interface is investigated at 1000degreesC on Pt point electrodes on YSZ and YSZ point contacts on Pt. Linear potential sweeps show a pronounced non-linear current-voltage relation and inductive hysteresis, in particular at l...

  12. Benchmarking Pt-based electrocatalysts for low temperature fuel cell reactions with the rotating disk electrode

    DEFF Research Database (Denmark)

    Pedersen, Christoffer Mølleskov; Escribano, Maria Escudero; Velazquez-Palenzuela, Amado Andres

    2015-01-01

    We present up-to-date benchmarking methods for testing electrocatalysts for polymer exchange membrane fuel cells (PEMFC), using the rotating disk electrode (RDE) method. We focus on the oxygen reduction reaction (ORR) and the hydrogen oxidation reaction (HOR) in the presence of CO. We have chosen...

  13. The oxidative burst reaction in mammalian cells depends on gravity.

    Science.gov (United States)

    Adrian, Astrid; Schoppmann, Kathrin; Sromicki, Juri; Brungs, Sonja; von der Wiesche, Melanie; Hock, Bertold; Kolanus, Waldemar; Hemmersbach, Ruth; Ullrich, Oliver

    2013-12-20

    Gravity has been a constant force throughout the Earth's evolutionary history. Thus, one of the fundamental biological questions is if and how complex cellular and molecular functions of life on Earth require gravity. In this study, we investigated the influence of gravity on the oxidative burst reaction in macrophages, one of the key elements in innate immune response and cellular signaling. An important step is the production of superoxide by the NADPH oxidase, which is rapidly converted to H2O2 by spontaneous and enzymatic dismutation. The phagozytosis-mediated oxidative burst under altered gravity conditions was studied in NR8383 rat alveolar macrophages by means of a luminol assay. Ground-based experiments in "functional weightlessness" were performed using a 2 D clinostat combined with a photomultiplier (PMT clinostat). The same technical set-up was used during the 13th DLR and 51st ESA parabolic flight campaign. Furthermore, hypergravity conditions were provided by using the Multi-Sample Incubation Centrifuge (MuSIC) and the Short Arm Human Centrifuge (SAHC). The results demonstrate that release of reactive oxygen species (ROS) during the oxidative burst reaction depends greatly on gravity conditions. ROS release is 1.) reduced in microgravity, 2.) enhanced in hypergravity and 3.) responds rapidly and reversible to altered gravity within seconds. We substantiated the effect of altered gravity on oxidative burst reaction in two independent experimental systems, parabolic flights and 2D clinostat / centrifuge experiments. Furthermore, the results obtained in simulated microgravity (2D clinorotation experiments) were proven by experiments in real microgravity as in both cases a pronounced reduction in ROS was observed. Our experiments indicate that gravity-sensitive steps are located both in the initial activation pathways and in the final oxidative burst reaction itself, which could be explained by the role of cytoskeletal dynamics in the assembly and function

  14. The oxidative burst reaction in mammalian cells depends on gravity

    OpenAIRE

    Adrian, A; Schoppmann, K; Sromicki, J; Brungs, S; von der Wiesche, M; Hock, B; Kolanus, W; Hemmersbach, R; Ullrich, O

    2013-01-01

    Gravity has been a constant force throughout the Earth's evolutionary history. Thus, one of the fundamental biological questions is if and how complex cellular and molecular functions of life on Earth require gravity. In this study, we investigated the influence of gravity on the oxidative burst reaction in macrophages, one of the key elements in innate immune response and cellular signaling. An important step is the production of superoxide by the NADPH oxidase, which is rapidly converted to...

  15. Multicompartment Artificial Organelles Conducting Enzymatic Cascade Reactions inside Cells

    DEFF Research Database (Denmark)

    Gallardo, Maria Godoy; Labay, Cédric Pierre; Trikalitis, Vasileios

    2017-01-01

    Cell organelles are subcellular structures entrapping a set of enzymes to achieve a specific functionality. The incorporation of artificial organelles into cells is a novel medical paradigm which might contribute to the treatment of various cell disorders by replacing malfunctioning organelles....... In particular, artificial organelles are expected to be a powerful solution in the context of enzyme replacement therapy since enzymatic malfunction is the primary cause of organelle dysfunction. Although several attempts have been made to encapsulate enzymes within a carrier vehicle, only few intracellularly...

  16. The reaction environment in a filter-press laboratory reactor: the FM01-LC flow cell

    International Nuclear Information System (INIS)

    Rivera, Fernando F.; León, Carlos Ponce de; Walsh, Frank C.; Nava, José L.

    2015-01-01

    A parallel plate cell facilitating controlled flow in a rectangular channel and capable of incorporating a wide range of electrode materials is important in studies of electrode reactions prior to process development and scale-up. The FM01-LC, a versatile laboratory-scale, plane parallel filter-press type electrochemical cell (having a projected electrode area of 64 cm 2 ) which is based on the larger FM21-SP electrolyser (2100 cm 2 area). Many laboratories have used this type of reactor to quantify the importance of reaction environment in fundamental studies and to prepare for industrial applications. A number of papers have concerned the experimental characterization and computational modelling of its reaction environment but the experimental and computational data has become dispersed. The cell has been used in a diverse range of synthesis and processing applications which require controlled flow and known reaction environment. In a previous review, the cell construction and reaction environment was summarised followed by the illustration of its use for a range of applications that include organic and inorganic electrosynthesis, metal ion removal, energy storage, environmental remediation (e.g., metal recycling or anodic destruction of organics) and drinking water treatment. This complementary review considers the characteristics of the FM01-LC electrolyser as an example of a well-engineered flow cell facilitating cell scale-up and provides a rigorous analysis of its reaction environment. Particular aspects include the influence of electrolyte velocity on mass transport rates, flow dispersion and current distribution

  17. Core-shell rhodium sulfide catalyst for hydrogen evolution reaction / hydrogen oxidation reaction in hydrogen-bromine reversible fuel cell

    Science.gov (United States)

    Li, Yuanchao; Nguyen, Trung Van

    2018-04-01

    Synthesis and characterization of high electrochemical active surface area (ECSA) core-shell RhxSy catalysts for hydrogen evolution oxidation (HER)/hydrogen oxidation reaction (HOR) in H2-Br2 fuel cell are discussed. Catalysts with RhxSy as shell and different percentages (5%, 10%, and 20%) of platinum on carbon as core materials are synthesized. Cyclic voltammetry is used to evaluate the Pt-equivalent mass specific ECSA and durability of these catalysts. Transmission electron microscopy (TEM), X-ray Photoelectron spectroscopy (XPS) and Energy-dispersive X-ray spectroscopy (EDX) techniques are utilized to characterize the bulk and surface compositions and to confirm the core-shell structure of the catalysts, respectively. Cycling test and polarization curve measurements in the H2-Br2 fuel cell are used to assess the catalyst stability and performance in a fuel cell. The results show that the catalysts with core-shell structure have higher mass specific ECSA (50 m2 gm-Rh-1) compared to a commercial catalyst (RhxSy/C catalyst from BASF, 6.9 m2 gm-Rh-1). It also shows better HOR/HER performance in the fuel cell. Compared to the platinum catalyst, the core-shell catalysts show more stable performance in the fuel cell cycling test.

  18. Development of a reaction cell for in-situ/operando studies of surface of a catalyst under a reaction condition and during catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Luan; Tao, Franklin, E-mail: franklin.tao.2011@gmail.com [Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Department of Chemical and Petroleum Engineering, University of Kansas, Lawrence, Kansas 66045 (United States)

    2016-06-15

    Tracking surface chemistry of a catalyst during catalysis is significant for fundamental understanding of catalytic performance of the catalyst since it allows for establishing an intrinsic correlation between surface chemistry of a catalyst at its working status and its corresponding catalytic performance. Ambient pressure X-ray photoelectron spectroscopy can be used for in-situ studies of surfaces of different materials or devices in a gas. To simulate the gaseous environment of a catalyst in a fixed-bed a flowing gaseous environment of reactants around the catalyst is necessary. Here, we report the development of a new flowing reaction cell for simulating in-situ study of a catalyst surface under a reaction condition in gas of one reactant or during catalysis in a mixture of reactants of a catalytic reaction. The homemade reaction cell is installed in a high vacuum (HV) or ultrahigh vacuum (UHV) environment of a chamber. The flowing gas in the reaction cell is separated from the HV or UHV environment through well sealings at three interfaces between the reaction cell and X-ray window, sample door and aperture of front cone of an energy analyzer. Catalyst in the cell is heated through infrared laser beam introduced through a fiber optics interfaced with the reaction cell through a homemade feedthrough. The highly localized heating on the sample holder and Au-passivated internal surface of the reaction cell effectively minimizes any unwanted reactions potentially catalyzed by the reaction cell. The incorporated laser heating allows a fast heating and a high thermal stability of the sample at a high temperature. With this cell, a catalyst at 800 °C in a flowing gas can be tracked readily.

  19. Development of a reaction cell for in-situ/operando studies of surface of a catalyst under a reaction condition and during catalysis

    International Nuclear Information System (INIS)

    Nguyen, Luan; Tao, Franklin

    2016-01-01

    Tracking surface chemistry of a catalyst during catalysis is significant for fundamental understanding of catalytic performance of the catalyst since it allows for establishing an intrinsic correlation between surface chemistry of a catalyst at its working status and its corresponding catalytic performance. Ambient pressure X-ray photoelectron spectroscopy can be used for in-situ studies of surfaces of different materials or devices in a gas. To simulate the gaseous environment of a catalyst in a fixed-bed a flowing gaseous environment of reactants around the catalyst is necessary. Here, we report the development of a new flowing reaction cell for simulating in-situ study of a catalyst surface under a reaction condition in gas of one reactant or during catalysis in a mixture of reactants of a catalytic reaction. The homemade reaction cell is installed in a high vacuum (HV) or ultrahigh vacuum (UHV) environment of a chamber. The flowing gas in the reaction cell is separated from the HV or UHV environment through well sealings at three interfaces between the reaction cell and X-ray window, sample door and aperture of front cone of an energy analyzer. Catalyst in the cell is heated through infrared laser beam introduced through a fiber optics interfaced with the reaction cell through a homemade feedthrough. The highly localized heating on the sample holder and Au-passivated internal surface of the reaction cell effectively minimizes any unwanted reactions potentially catalyzed by the reaction cell. The incorporated laser heating allows a fast heating and a high thermal stability of the sample at a high temperature. With this cell, a catalyst at 800 °C in a flowing gas can be tracked readily.

  20. High-performance Platinum-free oxygen reduction reaction and hydrogen oxidation reaction catalyst in polymer electrolyte membrane fuel cell.

    Science.gov (United States)

    Chandran, Priji; Ghosh, Arpita; Ramaprabhu, Sundara

    2018-02-26

    The integration of polymer electrolyte membrane fuel cell (PEMFC) stack into vehicles necessitates the replacement of high-priced platinum (Pt)-based electrocatalyst, which contributes to about 45% of the cost of the stack. The implementation of high-performance and durable Pt metal-free catalyst for both oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR) could significantly enable large-scale commercialization of fuel cell-powered vehicles. Towards this goal, a simple, scalable, single-step synthesis method was adopted to develop palladium-cobalt alloy supported on nitrogen-doped reduced graphene oxide (Pd 3 Co/NG) nanocomposite. Rotating ring-disk electrode (RRDE) studies for the electrochemical activity towards ORR indicates that ORR proceeds via nearly four-electron mechanism. Besides, the mass activity of Pd 3 Co/NG shows an enhancement of 1.6 times compared to that of Pd/NG. The full fuel cell measurements were carried out using Pd 3 Co/NG at the anode, cathode in conjunction with Pt/C and simultaneously at both anode and cathode. A maximum power density of 68 mW/cm 2 is accomplished from the simultaneous use of Pd 3 Co/NG as both anode and cathode electrocatalyst with individual loading of 0.5 mg/cm 2 at 60 °C without any backpressure. To the best of our knowledge, the present study is the first of its kind of a fully non-Pt based PEM full cell.

  1. A modelling approach to estimate carbon emissions from D.R.C. deforestation

    Science.gov (United States)

    Najdovski, Nicolas; Poulter, Benjamin; Defourny, Pierre; Moreau, Inès; Maignan, Fabienne; Ciais, Philippe; Verhegghen, Astrid; Kibambe Lubamba, Jean-Paul; Jungers, Quentin; De Weirdt, Marjolein; Verbeeck, Hans; MacBean, Natasha; Peylin, Philippe

    2014-05-01

    With its 1.8 million squared kilometres, the Congo basin dense forest represents the second largest contiguous forest of the world. These extensive forest ecosystems play a significant role in the regulation of global climate by their potential carbon dioxide emissions and carbon storage. Under a stable climate, the vegetation, assumed to be at the equilibrium, is known to present neutral emissions over a year with seasonal variations. However, modifications in temperatures, precipitations, CO2 atmospheric concentrations have the potential to modify this balance leading to higher or lower biomass storage. In addition, deforestation and forest degradation have played a significant role over the past several decades and are expected to become increasingly important in the future. Here, we quantify the relative effects of deforestation and 21st century climate change on carbon emissions in Congo Basin over the next three decades (2005-2035). Carbon dioxide emissions are estimated using a series of moderate resolution (10 km) vegetation maps merged with spatially explicit deforestation projections and developed to work with a prognostic carbon cycle model. The inversion of the deforestation model allowed hindcast land-use patterns back to 1800 by using land cover change rates based on the HYDE database. Simulations were made over the Democratic Republic of Congo (DRC) using the ORCHIDEE dynamic global vegetation model with climate forcing from the CMIP5 Representative Concentration Pathway 8.5 scenario for the HadGEM2. Two simulations were made, a reference simulation with land cover fixed at 2005 and a land cover change simulation with changing climate and CO2, to quantify the net land cover change emissions and climate emissions directly. Because of the relatively high resolution of the model simulations, the spatial patterns of human-driven carbon losses can be tracked in the context of climate change, providing information for mitigation and vulnerability

  2. Mixed Lichenoid and Follicular T- and B-Cell Lymphoid Reaction to Red Tattoos With Monoclonal T Cells.

    Science.gov (United States)

    Zaaroura, Hiba; Bergman, Reuven

    2017-09-28

    Pseudolymphomatous reactions have been described to occur in tattoos. Most cases have exhibited T-cell predominance and polyclonal T-cell receptor gene rearrangements. One case with monoclonal IgH gene rearrangements progressed into B-cell lymphoma. Lichenoid infiltrates are commonly described but lymphoid follicles much less frequently. We report a case with mixed lichenoid and follicular T- and B-cell reaction to red tattoos. The histopathology and the immunohistochemical studies were constant with a mixed T- and B-cell pseudolymphoma, the IgH gene rearrangement study was polyclonal, but the T-cell receptor gene rearrangement study was monoclonal. The patient who responded to intralesional corticosteroid injections remains under close scrutiny.

  3. Following Drug Uptake and Reactions inside Escherichia coli Cells by Raman Microspectroscopy

    Science.gov (United States)

    2015-01-01

    Raman microspectroscopy combined with Raman difference spectroscopy reveals the details of chemical reactions within bacterial cells. The method provides direct quantitative data on penetration of druglike molecules into Escherichia coli cells in situ along with the details of drug–target reactions. With this label-free technique, clavulanic acid and tazobactam can be observed as they penetrate into E. coli cells and subsequently inhibit β-lactamase enzymes produced within these cells. When E. coli cells contain a β-lactamase that forms a stable complex with an inhibitor, the Raman signature of the known enamine acyl–enzyme complex is detected. From Raman intensities it is facile to measure semiquantitatively the number of clavulanic acid molecules taken up by the lactamase-free cells during growth. PMID:24901294

  4. Proanthocyanidin-rich Pinus radiata bark extract inhibits mast cell-mediated anaphylaxis-like reactions.

    Science.gov (United States)

    Choi, Yun Ho; Song, Chang Ho; Mun, Sung Phil

    2018-02-01

    Mast cells play a critical role in the effector phase of immediate hypersensitivity and allergic reactions. Pinus radiata bark extract exerts multiple biological effects and exhibits immunomodulatory and antioxidant properties. However, its role in mast cell-mediated anaphylactic reactions has not been thoroughly investigated. In this study, we examined the effects of proanthocyanidin-rich water extract (PAWE) isolated from P. radiata bark on compound 48/80-induced or antidinitrophenyl (DNP) immunoglobulin E (IgE)-mediated anaphylaxis-like reactions in vivo. In addition, we evaluated the mechanism underlying the inhibitory effect of PAWE on mast cell activation, with a specific focus on histamine release, using rat peritoneal mast cells. PAWE attenuated compound 48/80-induced or anti-DNP IgE-mediated passive cutaneous anaphylaxis-like reactions in mice, and it inhibited histamine release triggered by compound 48/80, ionophore A23187, or anti-DNP IgE in rat peritoneal mast cells in vitro. Moreover, PAWE suppressed compound 48/80-elicited calcium uptake in a concentration-dependent manner and promoted a transient increase in intracellular cyclic adenosine-3',5'-monophosphate levels. Together, these results suggest that proanthocyanidin-rich P. radiata bark extract effectively inhibits anaphylaxis-like reactions. Copyright © 2017 John Wiley & Sons, Ltd.

  5. Solutes and cells - aspects of advection-diffusion-reaction phenomena in biochips

    DEFF Research Database (Denmark)

    Vedel, Søren

    2012-01-01

    the dependencies on density. This shows that the varied single-cell behavior including the overall modulations imposed by density arise as a natural consequence of pseudopod-driven motility in a social context. The final subproject concerns the combined effects of advection, diffusion and reaction of several......Cell’), and the overall title of the project is Solutes and cells — aspects of advection-diffusion-reaction phenomena in biochips. The work has consisted of several projects focusing on theory, and to some extend analysis of experimental data, with advection-diffusion-reaction phenomena of solutes as the recurring theme...... quantitatively interpret the proximal concentration of specific solutes, and integrate this to achieve biological functions. In three specific examples, the author and co-workers have investigated different aspects of the influence of advection, diffusion and reaction on solute distributions, as well...

  6. Progress in biocatalysis with immobilized viable whole cells: systems development, reaction engineering and applications

    Czech Academy of Sciences Publication Activity Database

    Polakovič, M.; Švitel, J.; Bučko, M.; Filip, J.; Neděla, Vilém; Ansorge-Schumacher, M.B.; Gemeiner, P.

    2017-01-01

    Roč. 39, č. 5 (2017), s. 667-683 ISSN 0141-5492 Institutional support: RVO:68081731 Keywords : biocatalysis * immobilization methods * immobilized whole-cell biocatalyst * multienzyme cascade reactions * process economics * reaction engineering Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering OBOR OECD: Bioprocessing technologies (industrial processes relying on biological agents to drive the process) biocatalysis, fermentation Impact factor: 1.730, year: 2016

  7. [The reaction of the neuroblastoma cells in the culture on the influence of tretionine and neurotoxine].

    Science.gov (United States)

    Magakian, Iu A; Karalian, Z A; Karalova, E M; Abroian, L O; Akopian, L A; Avetisian, A C; Semerdzhian, Z B

    2011-01-01

    Effect of the tretionine (retinoid) and aluminum chloride (neurotoxin) on the growth and differentiation of neuroblastoma cells in culture after their introduction into the medium separately and in combination was studied. The introduction of these substances creates a new information field in the medium, which becomes apparent by the reactions of neuroblastoma found on the populational and cellular levels of its organization. The presence of tretionine stimulates proliferation and induces differentiation of the cells into astrocytes. Aluminum chloride inhibits cell proliferation and enhances the process of their destruction in the monolayer. The variety of the reactions of neuroblastoma cells to the presence of these substances in the medium indicates the existence and functioning of a mechanism that selects from the information introduced only the portion which may contribute to adaptation of neuroblastoma cells to the changed culture conditions.

  8. Role of Mast Cells in Oral Lichen Planus and Oral Lichenoid Reactions.

    Science.gov (United States)

    Ramalingam, Suganya; Malathi, Narasimhan; Thamizhchelvan, Harikrishnan; Sangeetha, Narasimhan; Rajan, Sharada T

    2018-01-01

    Oral lichen planus (OLP) is a chronic T cell mediated disease of oral mucosa, skin, and its appendages with a prevalence of 0.5 to 2.6% worldwide. Oral lichenoid reactions (OLR) are a group of lesions with diverse aetiologies but have clinical and histological features similar to OLP, thereby posing a great challenge in differentiating both lesions. Mast cells are multifunctional immune cells that play a major role in the pathogenesis of lichen planus by release of certain chemical mediators. Increased mast cell densities with significant percentage of degranulation have been observed as a consistent finding in pathogenesis of oral lichen planus. The current study was aimed at quantifying the mast cells in histopathological sections of OLP and OLR thereby aiding a means of distinguishing these lesions. The study group involved 21 cases of oral lichen planus, 21 cases of oral lichenoid reactions, and 10 control specimens of normal buccal mucosa. All the cases were stained with Toluidine Blue and routine haematoxylin and eosin and the mast cells were quantified. The results were analyzed using the Kruskal-Wallis test and an intergroup analysis was performed using Mann-Whitney U test. The number of mast cells showed an increased value in oral lichen planus when compared to oral lichenoid reaction and thus an estimation of mast cells count could aid in distinguishing OLP from OLR histopathologically.

  9. Family Planning Supply Environment in Kinshasa, DRC: Survey Findings and Their Value in Advancing Family Planning Programming

    Science.gov (United States)

    Kayembe, Patrick; Babazadeh, Saleh; Dikamba, Nelly; Akilimali, Pierre; Hernandez, Julie; Binanga, Arsene; Bertrand, Jane T

    2015-01-01

    Background: Modern contraceptive prevalence was 14.1% in 2007 in Kinshasa, the capital city of the Democratic Republic of the Congo (DRC). Yet virtually nothing was known about the family planning supply environment. Methods: Three surveys of health facilities were conducted in 2012, 2013, and 2014 to determine the number, spatial distribution, and attributes of sites providing family planning services. The 2012 and 2013 surveys aimed to identify the universe of family planning facilities while obtaining a limited set of data on “readiness” to provide family planning services (defined as having at least 3 modern methods, at least 1 person training in family planning in the last 3 years, and an information system to track distribution of products to clients) and output (measured by couple-years of protection, or CYP). In contrast, the 2014 survey, conducted under the umbrella of the Performance Monitoring and Accountability 2020 (PMA2020) project, was based on 2-stage cluster sampling. This article provides detailed analysis of the 2012 and 2013 surveys, including bivariate and multivariate analysis of correlates of readiness to provide services and of output. Results: We identified 184 health facilities that reported providing at least 1 contraceptive method in 2012 and 395 facilities in 2013. The percentage of sites defined as “ready” to provide services increased from 44.1% in 2012 to 63.3% in 2013. For the 3-month period between January and March 2013, facilities distributed between 0 and 879.2 CYP (mean, 39.7). Nearly half (49%) of the CYP was attributable to implants, followed by IUDs (24%), CycleBeads (11%), and injectables (8%). In 2013, facilities supported by PEPFAR (n = 121) were more likely than other facilities to be rated as ready to provide services (Pplanning implementing agencies (Pplanning in the DRC in many ways, including mobilizing partners to increase contraceptive access and increasing donor investment in family planning in the DRC

  10. Malnutrition among children under the age of five in the Democratic Republic of Congo (DRC): does geographic location matter?

    Science.gov (United States)

    Kandala, Ngianga-Bakwin; Madungu, Tumwaka P; Emina, Jacques B O; Nzita, Kikhela P D; Cappuccio, Francesco P

    2011-04-25

    Although there are inequalities in child health and survival in the Democratic Republic of Congo (DRC), the influence of distal determinants such as geographic location on children's nutritional status is still unclear. We investigate the impact of geographic location on child nutritional status by mapping the residual net effect of malnutrition while accounting for important risk factors. We examine spatial variation in under-five malnutrition with flexible geo-additive semi-parametric mixed model while simultaneously controlling for spatial dependence and possibly nonlinear effects of covariates within a simultaneous, coherent regression framework based on Markov Chain Monte Carlo techniques. Individual data records were constructed for children. Each record represents a child and consists of nutritional status information and a list of covariates. For the 8,992 children born within the last five years before the survey, 3,663 children have information on anthropometric measures.Our novel empirical approach is able to flexibly determine to what extent the substantial spatial pattern of malnutrition is driven by detectable factors such as socioeconomic factors and can be attributable to unmeasured factors such as conflicts, political, environmental and cultural factors. Although childhood malnutrition was more pronounced in all provinces of the DRC, after accounting for the location's effects, geographic differences were significant: malnutrition was significantly higher in rural areas compared to urban centres and this difference persisted after multiple adjustments. The findings suggest that models of nutritional intervention must be carefully specified with regard to residential location. Childhood malnutrition is spatially structured and rates remain very high in the provinces that rely on the mining industry and comparable to the level seen in Eastern provinces under conflicts. Even in provinces such as Bas-Congo that produce foods, childhood malnutrition is

  11. Malnutrition among children under the age of five in the Democratic Republic of Congo (DRC: does geographic location matter?

    Directory of Open Access Journals (Sweden)

    Nzita Kikhela PD

    2011-04-01

    Full Text Available Abstract Background Although there are inequalities in child health and survival in the Democratic Republic of Congo (DRC, the influence of distal determinants such as geographic location on children's nutritional status is still unclear. We investigate the impact of geographic location on child nutritional status by mapping the residual net effect of malnutrition while accounting for important risk factors. Methods We examine spatial variation in under-five malnutrition with flexible geo-additive semi-parametric mixed model while simultaneously controlling for spatial dependence and possibly nonlinear effects of covariates within a simultaneous, coherent regression framework based on Markov Chain Monte Carlo techniques. Individual data records were constructed for children. Each record represents a child and consists of nutritional status information and a list of covariates. For the 8,992 children born within the last five years before the survey, 3,663 children have information on anthropometric measures. Our novel empirical approach is able to flexibly determine to what extent the substantial spatial pattern of malnutrition is driven by detectable factors such as socioeconomic factors and can be attributable to unmeasured factors such as conflicts, political, environmental and cultural factors. Results Although childhood malnutrition was more pronounced in all provinces of the DRC, after accounting for the location's effects, geographic differences were significant: malnutrition was significantly higher in rural areas compared to urban centres and this difference persisted after multiple adjustments. The findings suggest that models of nutritional intervention must be carefully specified with regard to residential location. Conclusion Childhood malnutrition is spatially structured and rates remain very high in the provinces that rely on the mining industry and comparable to the level seen in Eastern provinces under conflicts. Even in

  12. Navigating obstacles, opportunities and reforms: women’s lives and livelihoods in artisanal mining communities in eastern DRC

    OpenAIRE

    Bashwira Nyenyezi, Marie Rose

    2017-01-01

    For more than two decades, the exploitation and trade of minerals has fuelled armed conflict and fostered a climate of insecurity that has led to the deaths of thousands of people in eastern Democratic Republic of the Congo (DRC) (Katanga, Ituri, Maniema, North and South Kivu). This has been seen as a consequence of prolonged socioeconomic and political instability since the late 1980s and 1990s, when a civil war led to the collapse of the Zairian state and there were civil wars in neighbouri...

  13. Regularities of development of unspecific reaction of cells, and modification of chemical protection

    International Nuclear Information System (INIS)

    Veksler, A.M.; Korystov, Yu.N.; Kublik, L.N.; Ehjdus, L.Kh.

    1979-01-01

    Regularities of development of a unspecific reaction of cells under the effect of different substances belonging to weak electrolytes have been studied. It was demonstrated that the rate of the unspecific reaction development under the effect of cysteamine and caffeine-benzoate depends on the agent concentration, temperature and pH of a medium. It was established that the response of a cell is determined by the overall intracellular concentration of the agent rather than by its specific character. The total concentration of the substance inside the cell depends on its physico-chemical characteristics and, with a pH gradient between cell and medium, can markedly vary from that in the medium. With similar intracellular content, both substances proved to be virtually equally effective. This suggests that it is possible to assess the effectiveness of some other biologically active substances many of which are weak electrolytes

  14. Determination of total selenium and Se-77 in isotopically enriched human samples by ICP-dynamic reaction cell-MS

    DEFF Research Database (Denmark)

    Sloth, Jens Jørgen; Larsen, Erik Huusfeldt; Bügel, Susanne H.

    2003-01-01

    and the digested faecal samples were diluted using an aqueous diluent containing 0.5% Triton X-100, 2% nitric acid and 3% methanol. Selenium was detected as Se-76, Se-77 and Se-80 by ICP- DRC- MS. Selenium originating from the natural isotope abundance yeast and other selenium sources from the diet was determined...

  15. Electrochemical reaction rates in a dye sentisised solar cell - the iodide/tri-iodide redox system

    DEFF Research Database (Denmark)

    Bay, Lasse; West, Keld; Winter-Jensen, Bjørn

    2006-01-01

    The electrochemical reaction rate of the redox couple iodide / tri-iodide in acetonitrile is characterised by impedance spectroscopy. Different electrode materials relevant for the function of dye-sensitised solar cells (DSSC) are investigated. Preferably, the reaction with the iodide / tri......-iodide couple should be fast at the counter electrode, i.e. this electrode must have a high catalytic activity towards the redox couple, and the same reaction must be slow on the photo electrode. The catalytic activity is investigated for platinum, poly(3,4-ethylenedioxythiophene) (PEDOT), polypyrrole (PPy......), and polyaniline (PANI) - all deposited onto fluorine doped tin oxide (FTO) glass. Both Pt and PEDOT are found to have sufficiently high catalytic activities for practical use as counter electrode in DSSC. The reaction resistance on FTO and anatase confirmed the beneficial effect of a compact anatase layer on top...

  16. Electrochemical characteristics of vanadium redox reactions on porous carbon electrodes for microfluidic fuel cell applications

    International Nuclear Information System (INIS)

    Lee, Jin Wook; Hong, Jun Ki; Kjeang, Erik

    2012-01-01

    Microfluidic vanadium redox fuel cells are membraneless and catalyst-free fuel cells comprising a microfluidic channel network with two porous carbon electrodes. The anolyte and catholyte for fuel cell operation are V(II) and V(V) in sulfuric acid based aqueous solution. In the present work, the electrochemical characteristics of the vanadium redox reactions are investigated on commonly used porous carbon paper electrodes and compared to a standard solid graphite electrode as baseline. Half-cell electrochemical impedance spectroscopy is applied to measure the overall ohmic resistance and resistivity of the electrodes. Kinetic parameters for both V(II) and V(V) discharging reactions are extracted from Tafel plots and compared for the different electrodes. Cyclic voltammetry techniques reveal that the redox reactions are irreversible and that the magnitudes of peak current density vary significantly for each electrode. The obtained kinetic parameters for the carbon paper are implemented into a numerical simulation and the results show a good agreement with measured polarization curves from operation of a microfluidic vanadium redox fuel cell employing the same material as flow-through porous electrodes. Recommendations for microfluidic fuel cell design and operation are provided based on the measured trends.

  17. Anaphylactic Reactions After Discontinuation of Hymenoptera Venom Immunotherapy: A Clonal Mast Cell Disorder Should Be Suspected.

    Science.gov (United States)

    Bonadonna, Patrizia; Zanotti, Roberta; Pagani, Mauro; Bonifacio, Massimiliano; Scaffidi, Luigi; Olivieri, Elisa; Franchini, Maurizio; Reccardini, Federico; Costantino, Maria Teresa; Roncallo, Chiara; Mauro, Marina; Boni, Elisa; Rizzini, Fabio Lodi; Bilò, Maria Beatrice; Marcarelli, Anna Rosaria; Passalacqua, Giovanni

    2017-12-16

    Up to 75% of patients with severe anaphylactic reactions after Hymenoptera sting are at risk of further severe reactions if re-stung. Venom immunotherapy (VIT) is highly effective in protecting individuals with ascertained Hymenoptera venom allergy (HVA) and previous severe reactions. After a 3- to 5-year VIT course, most patients remain protected after VIT discontinuation. Otherwise, a lifelong treatment should be considered in high-risk patients (eg, in mastocytosis). Several case reports evidenced that patients with mastocytosis and HVA, although protected during VIT, can re-experience severe and sometimes fatal reactions after VIT discontinuation. To evaluate whether patients who lost protection after VIT discontinuation may suffer from clonal mast cell disorders. The survey describes the characteristics of patients who received a full course of VIT for previous severe reactions and who experienced another severe reaction at re-sting after VIT discontinuation. Those with a Red Española de Mastocitosis score of 2 or more or a serum basal tryptase level of more than 25 ng/mL underwent a hematological workup (bone marrow biopsy, KIT mutation, expression of aberrant CD25) and/or skin biopsy. Nineteen patients (mean age, 56.3 years; 89.5% males) were evaluated. All of them had received at least 4 years of VIT and were protected. After VIT discontinuation they were re-stung and developed, in all but 1 case, severe anaphylactic reactions (12 with loss of consciousness, in the absence of urticaria/angioedema). Eighteen patients (94.7%) had a clonal mast cell disorder, 8 of them with normal tryptase. Looking at this selected population, we suggest that mastocytosis should be considered in patients developing severe reactions at re-sting after VIT discontinuation and, as a speculation, patients with mastocytosis and HVA should be VIT-treated lifelong. Copyright © 2017. Published by Elsevier Inc.

  18. Hybrid direct carbon fuel cells and their reaction mechanisms - a review

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Kammer Hansen, Kent

    2014-01-01

    with carbon capture and storage (CCS) due to the high purity of CO2 emitted in the exhaust gas. Direct carbon (or coal) fuel cells (DCFCs) are directly fed with solid carbon to the anode chamber. The fuel cell converts the carbon at the anode and the oxygen at the cathode into electricity, heat and reaction......As coal is expected to continue to dominate power generation demands worldwide, it is advisable to pursue the development of more efficient coal power generation technologies. Fuel cells show a much higher fuel utilization efficiency, emit fewer pollutants (NOx, SOx), and are more easily combined...

  19. Predicting the diagenetic evolution of argillite repositories: application of flow-through reaction cells

    International Nuclear Information System (INIS)

    Warr, L.; Clatter, N.; Liewig, N.

    2005-01-01

    In order to successfully predict the diagenetic evolution of argillite repositories we need to know i) which reactions occur under a defined set of conditions, ii) how these reactions modify the material properties of the argillite seal, and iii) how fast these chemical reactions take place. Based on the application of thermodynamics, and the construction of activity diagrams for low temperature mineral phases (e.g. Velde 1992), fair predictions of mineral stability can be made under a given set of physical and chemical conditions. Such predictions are strengthened by examining natural mineral reactions preserved in the geological record, in combination with results obtained from controlled laboratory experiments. Changes in the material behavior can also be reasonably assessed, as the basic physical and chemical properties of argillaceous rocks of varying mineralogy are well documented in the petrophysical and engineering literature (e.g. Bell, 1999). Probably the most difficult task, however, is to assess the rates of the chemical reactions involved. This difficulty reflects our poor knowledge of the reaction kinetics for these low-temperature, fine-grained mineral materials, and apparent differences between rates estimated from natural and experimental systems. A new approach to monitoring the reaction kinetics of fine-grained minerals in percolating solution has been developed using flow-through reaction (wet-cell) chambers. These devices can be routinely mounted onto the X-ray diffractometer for in-situ measurements of the sample. With the aid of a cap to maintain constant volume, the device can be subjected to diagenetic or hydrothermal conditions (<150 C). First results are here presented for the alteration of Callovo-Oxfordian shales in a reactive simple young fluid (strongly alkaline, pH ca. 13) at 90 C, designed to simulate the alteration of concrete at the repository site. (authors)

  20. Reactivity of inducer cell subsets and T8-cell activation during the human autologous mixed lymphocyte reaction.

    Science.gov (United States)

    Romain, P L; Morimoto, C; Daley, J F; Palley, L S; Reinherz, E L; Schlossman, S F

    1984-01-01

    To characterize the responding T cells in the autologous mixed lymphocyte reaction (AMLR), T cells were fractionated into purified subpopulations employing monoclonal antibodies and a variety of separation techniques including fluorescence-activated cell sorting. It was found that isolated T4 cells, but not T8 cells, proliferated in response to autologous non-T cells. More importantly, within the T4 subset, the autoreactive population was greatly enriched in a fraction reactive with an autoantibody from patients with juvenile chronic arthritis (JRA) or the monoclonal antibody anti-TQ1. Although T8 cells themselves were unable to proliferate in the AMLR, they could be induced to respond in the presence of either T4 cells or exogenous IL-2 containing medium. This was demonstrated by direct measurement of tritiated thymidine uptake by T8 cells during the course of the AMLR as well as by analysis of their relative DNA content. Taken together, these data indicate that the AMLR represents a complex pattern of immune responsiveness distinct from that observed in response to soluble antigen or alloantigen. The precise function of this T-cell circuit remains to be determined.

  1. Rational design of competitive electrocatalysts for the oxygen reduction reaction in hydrogen fuel cells

    Science.gov (United States)

    Stolbov, Sergey; Alcántara Ortigoza, Marisol

    2012-02-01

    The large-scale application of one of the most promising clean and renewable sources of energy, hydrogen fuel cells, still awaits efficient and cost-effective electrocatalysts for the oxygen reduction reaction (ORR) occurring on the cathode. We demonstrate that truly rational design renders electrocatalysts possessing both qualities. By unifying the knowledge on surface morphology, composition, electronic structure and reactivity, we solve that sandwich-like structures are an excellent choice for optimization. Their constituting species couple synergistically yielding reaction-environment stability, cost-effectiveness and tunable reactivity. This cooperative-action concept enabled us to predict two advantageous ORR electrocatalysts. Density functional theory calculations of the reaction free-energy diagrams confirm that these materials are more active toward ORR than the so far best Pt-based catalysts. Our designing concept advances also a general approach for engineering materials in heterogeneous catalysis.

  2. Reaction of long-lived radicals and vitamin C in γ-irradiated mammalian cells and their model system at 295 K. Tunneling reaction in biological system

    International Nuclear Information System (INIS)

    Matsumoto, Takuro; Miyazaki, Tetsuo; Kosugi, Yoshio; Kumada, Takayuki; Koyama, Sinji; Kodama, Seiji; Watanabe, Masami.

    1996-01-01

    When golden hamster embryo (GHE) cells or concentrated albumin solution (0.1 kg dm -3 ) that is a model system of cells is irradiated with γ-rays at 295 K, organic radicals produced can be observed by ESR. The organic radicals survive at both 295 K and 310 K for such a long time as 20 hr. The long-lived radicals in GHE cells and the albumin solution react with vitamin C by the rate constants of 0.007 dm 3 mol -1 s -1 and 0.014 dm 3 mol -1 s -1 , respectively. The long-lived radicals in human cells cause gene mutation, which is suppressed by addition of vitamin C. The isotope effect on the rate constant (k) for the reaction of the long-lived radicals and vitamin C has been studied in the albumin solution by use of protonated vitamin C and deuterated vitamin C. The isotope effect (k H /k D ) was more than 20-50 and was interpreted in terms of tunneling reaction. When GHE cells or the aqueous albumin solution (0.1 kg dm -3 ) is irradiated with γ-rays at 295 K, organic radicals produced survive for more than 24 hr at room temperature. Very recently we have found that vitamin C reacts with the long-lived organic radicals in the γ-irradiated albumin solution at high concentration of 0.1 kg dm -3 by the rate constant of 0.014 dm 3 mol -1 s -1 . Since most of reactions in biological systems including the reaction of vitamin C are a transfer of a hydrogen atom or a proton that has a large wave character, it is generally expected that the tunneling reaction may play an important role in biological systems at room temperature. The studies of isotope effects on reactions will give an information on the contribution of tunneling reaction. (J.P.N.)

  3. The limits of corporate social responsibility and the possibilities for harnessing mining to reinstitute processes of state-led local development in the DRC

    NARCIS (Netherlands)

    B. Radley (Ben)

    2016-01-01

    textabstractParallel with the increasing liberalisation of the Congolese economy since the turn of the century has been the increasing delegation of previously state-held functions in the Democratic Republic of the Congo (DRC) to corporate actors, and in particular transnational mining corporations

  4. Min(d)ing the land: The relationship between artisanal and small-scale mining and surface land arrangements in the southern Philippines, eastern DRC and Liberia

    NARCIS (Netherlands)

    Verbrugge, B.L.P.; Cuvelier, J.; Bockstael, S. van

    2015-01-01

    This article examines the relationship between artisanal and small-scale mining (ASM) and surface land tenure arrangements, through a comparison of mining areas in the southern Philippines, the eastern DRC and Liberia. In all three cases, ASM takes place in peripheral regions outside central state

  5. Modeling the reaction kinetics of a hydrogen generator onboard a fuel cell -- Electric hybrid motorcycle

    Science.gov (United States)

    Ganesh, Karthik

    Owing to the perceived decline of the fossil fuel reserves in the world and environmental issues like pollution, conventional fuels may be replaced by cleaner alternative fuels. The potential of hydrogen as a fuel in vehicular applications is being explored. Hydrogen as an energy carrier potentially finds applications in internal combustion engines and fuel cells because it is considered a clean fuel and has high specific energy. However, at 6 to 8 per kilogram, not only is hydrogen produced from conventional methods like steam reforming expensive, but also there are storage and handling issues, safety concerns and lack of hydrogen refilling stations across the country. The purpose of this research is to suggest a cheap and viable system that generates hydrogen on demand through a chemical reaction between an aluminum-water slurry and an aqueous sodium hydroxide solution to power a 2 kW fuel cell on a fuel cell hybrid motorcycle. This reaction is essentially an aluminum-water reaction where sodium hydroxide acts as a reaction promoter or catalyst. The Horizon 2000 fuel cell used for this purpose has a maximum hydrogen intake rate of 28 lpm. The study focuses on studying the exothermic reaction between the reactants and proposes a rate law that best describes the rate of generation of hydrogen in connection to the surface area of aluminum available for the certain reaction and the concentration of the sodium hydroxide solution. Further, the proposed rate law is used in the simulation model of the chemical reactor onboard the hybrid motorcycle to determine the hydrogen flow rate to the fuel cell with time. Based on the simulated rate of production of hydrogen from the chemical system, its feasibility of use on different drive cycles is analyzed. The rate of production of hydrogen with a higher concentration of sodium hydroxide and smaller aluminum powder size was found to enable the installation of the chemical reactor on urban cycles with frequent stops and starts

  6. Oxygen consumption through metabolism and photodynamic reactions in cells cultured on microbeads

    International Nuclear Information System (INIS)

    Schunck, T.; Poulet, P.

    2000-01-01

    Oxygen consumption by cultured cells, through metabolism and photosensitization reactions, has been calculated theoretically. From this result, we have derived the partial oxygen pressure P O 2 in the perfusion medium flowing across sensitized cultured cells during photodynamic experiments. The P O 2 variations in the perfusate during light irradiation are related to the rate of oxygen consumption through photoreactions, and to the number of cells killed per mole of oxygen consumed through metabolic processes. After irradiation, the reduced metabolic oxygen consumption yields information on the cell death rate, and on the photodynamic cell killing efficiency. The aim of this paper is to present an experimental set-up and the corresponding theoretical model that allows us to control the photodynamic efficiency for a given cell-sensitizer pair, under well defined and controlled conditions of irradiation and oxygen supply. To demonstrate the usefulness of the methodology described, CHO cells cultured on microbeads were sensitized with pheophorbide a and irradiated with different light fluence rates. The results obtained, i.e. oxygen consumption of about 0.1 μMs -1 m -3 under a light fluence rate of 1 W m -2 , 10 5 cells killed per mole of oxygen consumed and a decay rate of about 1 h -1 of living cells after irradiation, are in good agreement with the theoretical predictions and with previously published data. (author)

  7. Aborted germinal center reactions and B cell memory by follicular T cells specific for a B cell receptor V region peptide.

    Science.gov (United States)

    Heiser, Ryan A; Snyder, Christopher M; St Clair, James; Wysocki, Lawrence J

    2011-07-01

    A fundamental problem in immunoregulation is how CD4(+) T cells react to immunogenic peptides derived from the V region of the BCR that are created by somatic mechanisms, presented in MHC II, and amplified to abundance by B cell clonal expansion during immunity. BCR neo Ags open a potentially dangerous avenue of T cell help in violation of the principle of linked Ag recognition. To analyze this issue, we developed a murine adoptive transfer model using paired donor B cells and CD4 T cells specific for a BCR-derived peptide. BCR peptide-specific T cells aborted ongoing germinal center reactions and impeded the secondary immune response. Instead, they induced the B cells to differentiate into short-lived extrafollicular plasmablasts that secreted modest quantities of Ig. These results uncover an immunoregulatory process that restricts the memory pathway to B cells that communicate with CD4 T cells via exogenous foreign Ag.

  8. Direct Light-up of cAMP Derivatives in Living Cells by Click Reactions

    Directory of Open Access Journals (Sweden)

    Yan Xu

    2013-10-01

    Full Text Available 8-Azidoadenosine 3′,5′-cyclic monophosphate (8-azido cAMP was directly detected in living cells, by applying Cu-free azide-alkyne cycloaddition to probe cAMP derivatives by fluorescence light-up. Fluorescence emission was generated by two non-fluorescent molecules, 8-azido cAMP as a model target and difluorinated cyclooctyne (DIFO reagent as a probe. The azide-alkyne cycloaddition reaction between 8-azido cAMP and DIFO induces fluorescence in 8-azido cAMP. The fluorescence emission serves as a way to probe 8-azido cAMP in cells.

  9. Pyridine nucleotides in regulation of cell death and survival by redox and non-redox reactions.

    Science.gov (United States)

    Novak Kujundžić, Renata; Žarković, Neven; Gall Trošelj, Koraljka

    2014-01-01

    Changes of the level and ratios of pyridine nucleotides determine metabolism- dependent cellular redox status and the activity of poly(ADP-ribose) polymerases (PARPs) and sirtuins, thereby influencing several processes closely related to cell survival and death. Pyridine nucleotides participate in numerous metabolic reactions whereby their net cellular level remains constant, but the ratios of NAD+/NADP+ and NADH/NADPH oscillate according to metabolic changes in response to diverse stress signals. In non-redox reactions, NAD+ is degraded and quickly, afterward, resynthesized in the NAD+ salvage pathway, unless overwhelming activation of PARP-1 consumes NAD+ to the point of no return, when the cell can no longer generate enough ATP to accommodate NAD+ resynthesis. The activity of PARP-1 is mandatory for the onset of cytoprotective autophagy on sublethal stress signals. It has become increasingly clear that redox status, largely influenced by the metabolism-dependent composition of the pyridine nucleotides pool, plays an important role in the synthesis of pro-apoptotic and anti-apoptotic sphingolipids. Awareness of the involvement of the prosurvival sphingolipid, sphingosine-1-phosphate, in transition from inflammation to malignant transformation has recently emerged. Here, the participation of pyridine nucleotides in redox and non-redox reactions, sphingolipid metabolism, and their role in cell fate decisions is reviewed.

  10. Study of the kinetics and morphology of immune reaction spleen cells by immunocytoadherence method. IV

    International Nuclear Information System (INIS)

    Blazek, J.

    1976-01-01

    The course of immunocytoadherence was followed in the mouse spleen during primary immune response to intraperitoneal administration of sheep erythrocytes at 24 hours, 72 hours and 6 days following whole-body irradiation with a dose of 450 R after antigen administration. The number of RFC becomes reduced immediately after irradiation. The reduction thereof always correlates with a relative increase of macrophages. Small and medium-sized lymphocytes rapidly disappear from the population of rosette-forming cells. If the irradiation had been carried out before the radiation-uninfluenced reaction reached its maximum, the large lymphocytes relatively increase in number. In other cases their immunocytoadherent activity also shows a steadily decreasing tendency. During the primary reaction, irradiation always increases the total relative plasma cell count as related to the other RFC. In such cases the proportion of mature forms is larger than of blastic forms. The values observed at the end of the studied postirradiation period in the course of the primary reaction are always characterized by a higher proportion of the plasma cell line after about 20 to 25 days. (author)

  11. Reaction between nitracrine and glutathione: implications for hypoxic cell radiosensitization and cytotoxicity

    International Nuclear Information System (INIS)

    Wilson, W.R.; Anderson, R.F.

    1989-01-01

    Nitracrine (NC) is an electron affinic DNA intercalating agent and a potent hypoxia-selective cytotoxin and radiosensitizer in cell culture. Although NC is too cytotoxic and too rapidly metabolized to provide hypoxic cell radiosensitization in tumors, it is of mechanistic interest as an example of a DNA affinic radiosensitizer. We have observed a rapid chemical reaction between NC and reduced glutathione (GSH), which suggests that the observed potent in vitro cytotoxicity and radiosensitization might be dependent on thiol depletion by the large extracellular reservoir of drug. However, no GSH depletion was observed under conditions providing radiosensitization or rapid cell killing, and prior depletion of GSH by buthionine sulphoximine had no effect on cytotoxicity or formation of macromolecular adducts. Further, the intracellular reaction of NC with GSH is slower than predicted on the basis of the measured second order rate constant and the total intracellular concentrations of both species. The results are consistent with a role for DNA binding in protecting NC from reaction with GSH, and in improving the efficiency with which reduced electrophilic metabolites react with DNA in preference to GSH

  12. Amorphous metallic alloys for oxygen reduction reaction in a polymer electrolyte membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Huerta, R.; Guerra-Martinez, I.; Lopez, J.S. [Inst. Politecnico Nacional, ESIQIE, Mexico City (Mexico). Lab. de Electroquimica; Pierna, A.R. [Basque Country Univ., San Sebastian (Spain). Dept. of Chemical Engineering and Environment; Solorza-Feria, O. [Inst. Politenico Nacional, Centro de Investigacion y de Estudios Avanzados, Mexico City (Mexico). Dept. de Quimica

    2010-07-15

    Direct methanol fuel cells (DMFC) and polymer electrolyte membrane fuel cells (PEMFC) represent an important, environmentally clean energy source. This has motivated extensive research on the synthesis, characterization and evaluation of novel and stable oxygen reduction electrocatalysts for the direct four-electron transfer process to water formation. Studies have shown that amorphous alloyed compounds can be used as electrode materials in electrochemical energy conversion devices. Their use in PEMFCs can optimize the electrocatalyst loading in the membrane electrode assembly (MEA). In this study, amorphous metallic PtSn, PtRu and PtRuSn alloys were synthesized by mechanical milling and used as cathodes for the oxygen reduction reaction (ORR) in sulphuric acid and in a single PEM fuel cell. Two different powder morphologies were observed before and after the chemical activation in a hydrofluoric acid (HF) solution at 25 degrees C. The kinetics of the ORR on the amorphous catalysts were investigated. The study showed that the amorphous metallic PtSn electrocatalyst was the most active of the 3 electrodes for the cathodic reaction. Fuel cell experiments were conducted at various temperatures at 30 psi for hydrogen (H{sub 2}) and at 34 psi for oxygen (O{sub 2}). MEAs made of Nafion 115 and amorphous metallic PtSn dispersed on carbon powder in a PEMFC had a power density of 156 mW per cm{sup 2} at 0.43V and 80 degrees C. 12 refs., 1 tab., 5 figs.

  13. Li plating as unwanted side reaction in commercial Li-ion cells - A review

    Science.gov (United States)

    Waldmann, Thomas; Hogg, Björn-Ingo; Wohlfahrt-Mehrens, Margret

    2018-04-01

    Deposition of Lithium metal on anodes contributes significantly to ageing of Li-ion cells. Lithium deposition is connected not only to a drastic limitation of life-time, but also to fast-charging capability and safety issues. Lithium deposition in commercial Li-ion cells is not limited to operation conditions at low temperatures. In recent publications various types of commercial cells were investigated using complimentary analysis methods. Five cell types studied in literature (18650, 26650, pouch) serve as a basis for comparison when and why Li deposition happens in commercial Li-ion cells. In the present paper, we reviewed literature on (i) causes, (ii) hints and evidences for Li deposition, (iii) macroscopic morphology of Li deposition/plating, (iv) ageing mechanisms and shapes of capacity fade curves involving Li deposition, and (v) influences of Li deposition on safety. Although often discussed, safety issues regarding Li deposition are not only limited to dendrite growth and internal short circuits, but also to exothermic reactions in the presence of Lithium metal. Furthermore, we tried to connect knowledge from different length scales including the macroscopic level (Li-ion cells, operating conditions, gradients in cells, electrochemical tests, safety tests), the microscopic level (electrodes, particles, microstructure), and the atomic level (atoms, ions, molecules, energy barriers).

  14. Mechanism and kinetics of the electrocatalytic reaction responsible for the high cost of hydrogen fuel cells.

    Science.gov (United States)

    Cheng, Tao; Goddard, William A; An, Qi; Xiao, Hai; Merinov, Boris; Morozov, Sergey

    2017-01-25

    The sluggish oxygen reduction reaction (ORR) is a major impediment to the economic use of hydrogen fuel cells in transportation. In this work, we report the full ORR reaction mechanism for Pt(111) based on Quantum Mechanics (QM) based Reactive metadynamics (RμD) simulations including explicit water to obtain free energy reaction barriers at 298 K. The lowest energy pathway for 4 e - water formation is: first, *OOH formation; second, *OOH reduction to H 2 O and O*; third, O* hydrolysis using surface water to produce two *OH and finally *OH hydration to water. Water formation is the rate-determining step (RDS) for potentials above 0.87 Volt, the normal operating range. Considering the Eley-Rideal (ER) mechanism involving protons from the solvent, we predict the free energy reaction barrier at 298 K for water formation to be 0.25 eV for an external potential below U = 0.87 V and 0.41 eV at U = 1.23 V, in good agreement with experimental values of 0.22 eV and 0.44 eV, respectively. With the mechanism now fully understood, we can use this now validated methodology to examine the changes upon alloying and surface modifications to increase the rate by reducing the barrier for water formation.

  15. Separate effects of irradiation and of graft-versus-host reaction on rat mucosal mast cells

    International Nuclear Information System (INIS)

    Cummins, A.G.; Munro, G.H.; Huntley, J.F.; Miller, H.R.P.; Ferguson, A.

    1989-01-01

    T cell mediated immune responses in the gut can produce enteropathy and malabsorption. The authors investigated the relevance of mucosal mast cells (MMC) to the mechanisms of this enteropathy by using graft-versus-host reaction (GvHR) in the rat as a model of mucosal delayed type hypersensitivity. x-irradiation, with or without GvHR, led to the virtual disappearance of jejunal MMC, undetectable jejunal rat mast cell protease (RMCPII) and very low levels of RMCPII in serum (all p<0.01 when compared with unirradiated controls). These experiments show that there is a modest expansion in jejunal MMC in unirradiated rats with semiallogeneic GvHR, whereas irradiation, alone or associated with GvHR, profoundly depletes MMC for at least two weeks. The enteropathy of GvHR can evolve in the virtual absence of MMC. (author)

  16. Multi-elemental characterization of tunnel and road dusts in Houston, Texas using dynamic reaction cell-quadrupole-inductively coupled plasma–mass spectrometry: Evidence for the release of platinum group and anthropogenic metals from motor vehicles

    International Nuclear Information System (INIS)

    Spada, Nicholas; Bozlaker, Ayse; Chellam, Shankararaman

    2012-01-01

    Highlights: ► Analytical method for PGEs, main group, transition and rare earth metals developed. ► Comprehensive characterization of road and tunnel dust samples was accomplished. ► PGEs in dusts arise from autocatalyst attrition. ► Mobile sources also contributed to Cu, Zn, Ga, As, Mo, Cd, Sn, Sb, Ba, W and Pb. ► All other elements, including rare earths arose from crustal sources. - Abstract: Platinum group elements (PGEs) including Rh, Pd, and Pt are important tracers for vehicular emissions, though their measurement is often challenging and difficult to replicate in environmental campaigns. These challenges arise from sample preparation steps required for PGE quantitation, which often cause severe isobaric interferences and spectral overlaps from polyatomic species of other anthropogenically emitted metals. Consequently, most previous road dust studies have either only quantified PGEs or included a small number of anthropogenic elements. Therefore a novel analytical method was developed to simultaneously measure PGEs, lanthanoids, transition and main group elements to comprehensively characterize the elemental composition of urban road and tunnel dusts. Dust samples collected from the vicinity of high-traffic roadways and a busy underwater tunnel restricted to single-axle (predominantly gasoline-driven) vehicles in Houston, TX were analyzed for 45 metals with the newly developed method using dynamic reaction cell-quadrupole-inductively coupled plasma–mass spectrometry (DRC-q-ICP–MS). Average Rh, Pd and Pt concentrations were 152 ± 52, 770 ± 208 and 529 ± 130 ng g −1 respectively in tunnel dusts while they varied between 6 and 8 ng g −1 , 10 and 88 ng g −1 and 35 and 131 ng g −1 in surface road dusts. Elemental ratios and enrichment factors demonstrated that PGEs in dusts originated from autocatalyst attrition/abrasion. Strong evidence is also presented for mobile source emissions of Cu, Zn, Ga, As, Mo, Cd, Sn, Sb, Ba, W and Pb. However

  17. A Monte Carlo simulation of boron neutron capture reactions in cells - Microdosimetric aspects

    International Nuclear Information System (INIS)

    Nguyen, T.; Brownell, G.L.

    1992-01-01

    The neutron capture reaction in boron ( 10 B(n,α) 7 Li) generates two short-range particles with high LET. The effect of neutron capture therapy (NCT) depends on the microscopic distribution of 10 B atoms in target cells. Due to the short ranges of the charged particles, an intracellular localization of 10 B in one region may produce a different effect to the cell than the same concentration of 10 B localized in other regions. Monte Carlo calculations of the energy deposition produced by 10 B disintegrations were performed to compare the effectiveness of 10 B localized in five separate source regions of the modeled cells: nucleus, nuclear membrane, cytoplasm, plasma membrane, and extracellular space. Two regions (nucleus and the whole cell) were independently considered the sensitive targets for the radiation therapy. An effectiveness factor (EF), defined by combining the radiation dose resulting from the 10 B disintegrations with the distribution of 10 B in a cell population, was used to determine the effectiveness of 10 B(n,α) 7 Li reactions in different source regions. When an RBE and LET relationship was obtained from experimental data, the RBE values of the α and 7 Li radiations originating in different source regions were calculated, taking into account the stochastic nature of the origins of the 10 B disintegrations in these regions. The computations indicate that if the nucleus was the only radiation sensitive region, the nuclear 10 B disintegrations would be most effective for NCT, followed by 10 B disintegrations in the nuclear membrane (48% as effective). 10 B disintegrations in the cytoplasm, cell membrane, and extracellular space were about 10%, 5%, and 2%, respectively, as effective as nuclear 10 B

  18. Proteomic analysis of cellular response induced by boron neutron capture reaction in human squamous cell carcinoma SAS cells

    International Nuclear Information System (INIS)

    Sato, Akira; Itoh, Tasuku; Imamichi, Shoji; Kikuhara, Sota; Fujimori, Hiroaki; Hirai, Takahisa; Saito, Soichiro; Sakurai, Yoshinori; Tanaka, Hiroki; Nakamura, Hiroyuki; Suzuki, Minoru

    2015-01-01

    To understand the mechanism of cell death induced by boron neutron capture reaction (BNCR), we performed proteome analyses of human squamous tumor SAS cells after BNCR. Cells were irradiated with thermal neutron beam at KUR after incubation under boronophenylalanine (BPA)(+) and BPA(−) conditions. BNCR mainly induced typical apoptosis in SAS cells 24 h post-irradiation. Proteomic analysis in SAS cells suggested that proteins functioning in endoplasmic reticulum, DNA repair, and RNA processing showed dynamic changes at early phase after BNCR and could be involved in the regulation of cellular response to BNCR. We found that the BNCR induces fragments of endoplasmic reticulum-localized lymphoid-restricted protein (LRMP). The fragmentation of LRMP was also observed in the rat tumor graft model 20 hours after BNCT treatment carried out at the National Nuclear Center of the Republic of Kazakhstan. These data suggest that dynamic changes of LRMP could be involved during cellular response to BNCR. - Highlights: • BNCR in human squamous carcinoma cells caused typical apoptotic features. • BNCR induced fragments of LRMP, in human squamous carcinoma and rat tumor model. • The fragmentation of LRMP could be involved in cellular response to BNCR.

  19. Effect of washing on the plasma membrane and on stress reactions of cultured rose cells

    International Nuclear Information System (INIS)

    Qian, Y.C.; Nguyen, T.; Murphy, T.M.

    1993-01-01

    Cultured cells of Rosa damascena have been used as a model for studies of responses of plant cells to various stresses, including UV radiation, protein-synthesis inhibitors, and elicitors from pathogens. Many of the responses involve reactions at the plasma membrane: efflux of K + , changes in the acid balance between cytoplasm and external medium, synthesis of H 2 O 2 , and inhibition of ferricyanide reduction. In previous studies, the cells have typically been washed with a solution of low ionic strength. We now show that this washing procedure results in changes in the protein composition of the plasma membrane, in the labeling of the proteins in the plasma membrane, and in the specific activity of ATPase in purified plasma membrane vesicles. Also, compared to the unwashed cells, the washed cells show less net K + efflux after UV-C and Phytophthora elicitor treatments; more synthesis of H 2 O 2 after UV-C and a pattern of accumulation of H 2 O 2 after elicitor treatment that shows a delayed but higher peak; and more inhibition of ferricyanide reduction after UV-C, but not after elicitor treatment. The results suggest that washing has differential effects on the mechanisms by which cultured plant cells perceive or respond to two stresses, UV-C and elicitor

  20. Expanded adipose-derived stem cells suppress mixed lymphocyte reaction by secretion of prostaglandin E2.

    Science.gov (United States)

    Cui, Lei; Yin, Shuo; Liu, Wei; Li, Ningli; Zhang, Wenjie; Cao, Yilin

    2007-06-01

    Multipotent mesenchymal stem cells (MSCs) in adult tissue are known to be less immunogenic and immunosuppressive. Previous study showed that primary cultures of human adipose-derived stem cells (ADSCs) shared their immunomodulatory properties with other MSCs. However, whether passaged human ADSCs can retain their immunomodulatory effect after in vitro expansion remains unknown. In addition, the mechanism of ADSC-mediated immunomodulatory effect remains to be elucidated. This study aimed to investigate these issues by using passaged human ADSCs as an in vitro study model. Flow cytometry showed that passaged ADSCs expressed human leukocyte antigen (HLA) class I but not class II molecules, which could be induced to express to a high level with interferon-gamma (IFN-gamma) treatment. The study found that passaged ADSCs could not elicit lymphocyte proliferation after co-culturing with them, even after IFN-gamma treatment. In addition, either IFN-gamma-treated or non-treated ADSCs could inhibit phytohemagglutinin (PHA)-stimulated lymphocyte proliferation. Moreover, passaged ADSCs could serve as the third-party cells to inhibited two-way mixed lymphocyte reaction (MLR). Further study using a transwell system also showed that this type of immunosuppressive effect was not cell-cell contact dependent. In defining possible soluble factors, we found that passaged ADSCs significantly increased their secretion of prostaglandin E2 (PGE2), but not transforming growth factor-beta (TGF-beta) and hepatocyte growth factor (HGF), when they were co-cultured with MLR. Furthermore, the result demonstrated that only PGE2 production inhibitor indomethacine, but not TGF-beta- and HGF-neutralizing antibodies, could significantly counteract ADSC-mediated suppression on allogeneic lymphocyte proliferation. These results indicated that in vitro expanded ADSCs retain low immunogenicity and immunosuppressive effect, and PGE2 might be the major soluble factor involved in the in vitro inhibition of

  1. Patterns of development of unspecific reaction of cells and modification of chemical protection

    International Nuclear Information System (INIS)

    Veksler, A.M.; Korystov, Yu.N.; Kublik, L.N.; Ehjdus, L.Kh.

    1980-01-01

    A study was made of a correlation between radioprotective efficiency of different chemical agents (weak electrolytes) and conditions of treatment. It was demonstrated that the pattern of changes in the protection efficiency, with modification thereof, is similar to that of the development of unspecific reaction and determined by the intracellular concentration of the chemical agents, which, in turn, is function of physicochemical parameters of the substance and pH gradient between cell and medium. With similar intracellular concentration, caffeine-benzoate, thioglicolic acid and caffeine proved to be equally effective, while the protective effect of cysteamine was appreciably higher

  2. Raman Spectroscopy of Serpentine and Reaction Products at High Pressure Using a Diamond Anvil Cell

    Science.gov (United States)

    Burgess, K.; Zinin, P.; Odake, S.; Fryer, P.; Hellebrand, E.

    2012-12-01

    Serpentine is one of the most abundant hydrous phases in the altered subducting plate, and contributes a large portion of the water flux in subduction zones. Measuring and understanding the structural changes in serpentine with pressure aids our understanding of the processes ongoing in oceanic crust and subduction zones. We have conducted high-pressure/high-temperature experiments on serpentine and its dehydration reaction products using a diamond anvil cell. We used the multifunctional in-situ measurement system equipped with a Raman device and laser heating system at the University of Hawaii. Well-characterized natural serpentinite was used in the study. Pressure was determined using the shift of the fluorescence line of a ruby placed next to the sample. Raman spectra of serpentine were obtained at higher pressures than previously published, up to 15 GPa; the peak shift with pressure fits the model determined by Auzende et al. [2004] at lower pressures. Heating was done at several different pressures up to 20 GPa, and reaction products were identified using Raman. Micro-Raman techniques allow us to determine reaction progress and heterogeneity within natural samples containing olivine and serpentine. Auzende, A-L., I. Daniel, B. Reynard, C. Lemaire, F. Guyot (2004). High-pressure behavior of serpentine minerals: a Raman spectroscopic study. Phys. Chem. Minerals 31 269-277.

  3. Semi-analytical solutions of the Schnakenberg model of a reaction-diffusion cell with feedback

    Science.gov (United States)

    Al Noufaey, K. S.

    2018-06-01

    This paper considers the application of a semi-analytical method to the Schnakenberg model of a reaction-diffusion cell. The semi-analytical method is based on the Galerkin method which approximates the original governing partial differential equations as a system of ordinary differential equations. Steady-state curves, bifurcation diagrams and the region of parameter space in which Hopf bifurcations occur are presented for semi-analytical solutions and the numerical solution. The effect of feedback control, via altering various concentrations in the boundary reservoirs in response to concentrations in the cell centre, is examined. It is shown that increasing the magnitude of feedback leads to destabilization of the system, whereas decreasing this parameter to negative values of large magnitude stabilizes the system. The semi-analytical solutions agree well with numerical solutions of the governing equations.

  4. Transport phenomena in solid oxide fuel cell electrodes focusing on heat transfer related to chemical reactions

    International Nuclear Information System (INIS)

    Navasa, M; Andersson, M; Yuan, J; Sundén, B

    2012-01-01

    Solid oxide fuel cells (SOFCs) are widely studied for their advantages especially at high temperatures. However, operating at high temperatures represents a high cost due to the strict requirements the materials are expected to fulfill. Thus, the main goal in SOFC research has been to decrease the operating temperature so that the range of available materials is widened and hence, the operating cost can be reduced. In this paper, the different heat sources that contribute to the cell energy balance are presented with strong emphasis on the chemical reactions that take place in SOFCs. The knowledge of which heat sources or sinks taking place and their locations within the SOFC can provide useful information for further design and efficiency improvements.

  5. Mesothelial cell proliferation in the scala tympani: a reaction to the rupture of the round window membrane.

    Science.gov (United States)

    Sone, M

    1998-10-01

    The inner layer of the round window membrane is composed of mesothelial cells and this mesothelial cell layer extends to the scala tympani. This study describes the histopathologic findings of temporal bone analysis from a patient with bilateral perilymphatic fistula of the round window membrane. The left ear showed proliferation of mesothelial cells in the scala tympani of the basal turn adjoining the round window membrane. This cell proliferation is thought to be a reaction to the rupture of the round window membrane.

  6. Evaluation of urogenital Chlamydia trachomatis infections by cell culture and the polymerase chain reaction using a closed system

    DEFF Research Database (Denmark)

    Østergaard, Lars; Traulsen, J; Birkelund, Svend

    1991-01-01

    the two test systems were compared, the overall sensitivity of the polymerase chain reaction was 96% and the specificity 94% when compared to the cell culture technique. By use of a closed system for DNA extraction and sample transfer for the polymerase chain reaction, contamination of the samples......Two hundred and fifty-four specimens from males and females consulting a clinic for sexually transmitted diseases were analyzed for genital Chlamydia trachomatis infection. Each clinical sample was tested by the cell culture technique and the polymerase chain reaction using a closed system. When...... not detect Chlamydia trachomatis after sufficient antibiotic treatment of the chlamydial infections....

  7. Evaluation of urogenital Chlamydia trachomatis infections by cell culture and the polymerase chain reaction using a closed system

    DEFF Research Database (Denmark)

    Østergaard, Lars; Traulsen, J; Birkelund, Svend

    1993-01-01

    the two test systems were compared, the overall sensitivity of the polymerase chain reaction was 96% and the specificity 94% when compared to the cell culture technique. By use of a closed system for DNA extraction and sample transfer for the polymerase chain reaction, contamination of the samples......Two hundred and fifty-four specimens from males and females consulting a clinic for sexually transmitted diseases were analyzed for genital Chlamydia trachomatis infection. Each clinical sample was tested by the cell culture technique and the polymerase chain reaction using a closed system. When...... not detect Chlamydia trachomatis after sufficient antibiotic treatment of the chlamydial infections....

  8. Atmospheric pressure reaction cell for operando sum frequency generation spectroscopy of ultrahigh vacuum grown model catalysts

    Science.gov (United States)

    Roiaz, Matteo; Pramhaas, Verena; Li, Xia; Rameshan, Christoph; Rupprechter, Günther

    2018-04-01

    A new custom-designed ultrahigh vacuum (UHV) chamber coupled to a UHV and atmospheric-pressure-compatible spectroscopic and catalytic reaction cell is described, which allows us to perform IR-vis sum frequency generation (SFG) vibrational spectroscopy during catalytic (kinetic) measurements. SFG spectroscopy is an exceptional tool to study vibrational properties of surface adsorbates under operando conditions, close to those of technical catalysis. This versatile setup allows performing surface science, SFG spectroscopy, catalysis, and electrochemical investigations on model systems, including single crystals, thin films, and deposited metal nanoparticles, under well-controlled conditions of gas composition, pressure, temperature, and potential. The UHV chamber enables us to prepare the model catalysts and to analyze their surface structure and composition by low energy electron diffraction and Auger electron spectroscopy, respectively. Thereafter, a sample transfer mechanism moves samples under UHV to the spectroscopic cell, avoiding air exposure. In the catalytic cell, SFG spectroscopy and catalytic tests (reactant/product analysis by mass spectrometry or gas chromatography) are performed simultaneously. A dedicated sample manipulation stage allows the model catalysts to be examined from LN2 temperature to 1273 K, with gaseous reactants in a pressure range from UHV to atmospheric. For post-reaction analysis, the SFG cell is rapidly evacuated and samples are transferred back to the UHV chamber. The capabilities of this new setup are demonstrated by benchmark results of CO adsorption on Pt and Pd(111) single crystal surfaces and of CO adsorption and oxidation on a ZrO2 supported Pt nanoparticle model catalyst grown by atomic layer deposition.

  9. Study of ions - molecules reactions in the gas phase with collision reaction cell devices: Applications to the direct resolution of spectroscopic interferences in ICP-MS

    International Nuclear Information System (INIS)

    Favre, G.

    2008-12-01

    Inductively Coupled Plasma Mass Spectrometry emerged as the most widespread mass spectrometry technique in inorganic analytical chemistry for determining the concentration of a given isotope or an isotope ratio. The problem of spectroscopic interferences, inherent to this technique, finds a solution through the use of reaction cell devices. An in situ interference removal is feasible with the addition of a well selected gas in the cell. The understanding of the chemistry of ions-molecules interactions in the gas phase is however fundamental to optimize the efficiency of such devices. An accurate knowledge of experimental conditions in the reaction zone according to instrumental parameters appears crucial in order to interpret observed reactivities. This preliminary study is then used for the resolution of two nuclear field characteristic interferences. (author)

  10. Synthesis and characterization of Pd-Ni nanoalloy electrocatalysts for oxygen reduction reaction in fuel cells

    International Nuclear Information System (INIS)

    Zhao, Juan; Sarkar, Arindam; Manthiram, Arumugam

    2010-01-01

    Carbon-supported Pd-Ni nanoalloy electrocatalysts with different Pd/Ni atomic ratios have been synthesized by a modified polyol method, followed by heat treatment in a reducing atmosphere at 500-900 deg. C. The samples have been characterized by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), rotating disk electrode (RDE) measurements, and single-cell proton exchange membrane fuel cell (PEMFC) tests for oxygen reduction reaction (ORR). XRD and TEM data reveal an increase in the degree of alloying and particle size with increasing heat-treatment temperature. XPS data indicate surface segregation with Pd enrichment on the surface of Pd 80 Ni 20 after heat treatment at ≥500 deg. C, suggesting possible lattice strains in the outermost layers. Electrochemical data based on CV, RDE, and single-cell PEMFC measurement show that Pd 80 Ni 20 heated at 500 deg. C has the highest mass catalytic activity for ORR among the Pd-Ni samples investigated, with stability and catalytic activity significantly higher than that found with Pd. With a lower cost, the Pd-Ni catalysts exhibit higher tolerance to methanol than Pt, offering an added advantage in direct methanol fuel cells (DMFC).

  11. Rapid bioelectric reaction of elodea leaf cells to the UV radiation

    International Nuclear Information System (INIS)

    Aliev, D.A.; Mamedov, T.G.; Akhmedov, I.S.; Khalilov, R.I.

    1984-01-01

    It has been established that changes of membrane potential (MP) of elodea leaf cells in the UV radiation are manifested in a form of rapid response reaction, which is similar to an action potential. At present a lot of new data confirming the existence of electrogenic proton pump on plasmalemma plant cells is making their appearance. The plant cell membrane potential consists of two components: equilibrium( passive) potential and potential created by an electrogenic proton pump. A contribution of the second component to the elodea leaf cell MP is considerable and constitutes more than a half of the total MP. Constant values of membrane conductivity and intracell electric bonds in the process of depolarization development and after MP recovery testify to the fact, that UV radiation does not effect upon the MP passive component. High degree of depolarization and its strong dependence on medium pH and also the observed effect independence on potassium and sodium ions presence in the external medium testify to the fact that UV radiation ingenuously inactivates electrogenic proton pumps

  12. Mapping the above and belowground biomass in three landscapes in Cameroon, Rwanda and DRC: pilot cases in REDD+ pilot project.

    Science.gov (United States)

    Sufo Kankeu, R.

    2017-12-01

    A number of biomass/carbon maps have been recently produced using different approaches and despite their comparison there is still a gap. To fill this gap there is a need to provide accurate maps based on the field data on all types of land use and land cover. Based on the field data from plots established in three pilot projects around Virunga National park in Rwanda, Tri-national Sangha landscape in Cameroon and lac Télé-Lac Tumba landscape in DRC, this paper intend to analyse the relationship between land use change and biomass and present the variability through biomass/carbon maps. The above and belowground biomass was calculated from 95 nested plots of 20 meters radius. The value of biomass/carbon per plot were thus used to elaborate carbon maps of each study site. In the same the way the correlation between the land use and underground and above ground carbon stock were analysed using geographically weighted regression. These data have been joint with classified Spot 5 image and aggregated to come out will acceptable result. Results show that there is a strong relationship between land use in various project sites and the carbon stock related, the change of a forest cover directly impact on carbon stock/biomass.in the same way carbon map realized base on field data and IDW, Kriging or spline module show an idea on the carbon distribution but the maps are not accurate giving the distance between plots,

  13. Design of a low energy reaction cell for distributed power applications

    International Nuclear Information System (INIS)

    Miley, G.H.; Castano, C.; Okuniewski, M.; Selvaggi, G.; Lipson, A.

    2001-01-01

    Power units using Low Energy Nuclear Reactions (LENRs) potentially offer a radical new approach to power units that could provide distributed power units in the 1- 50 kW range. As described in an ICONE-8 paper (Miley, et al. 2000-c), these cells employ thin metallic film cathodes (order of 500.10 -10 m, using variously Ni, Pd and Ti) with electrolytes such as 0.5-1 molar lithium sulfate in light water. Power densities exceeding 10 W/cc in the films have been achieved. An ultimate goal is to incorporate this thin-film technology into a 'tightly packed' cell design where the film material occupies ∼20% of the total volume. If this is achieved, power densities of ∼20 W/cm 3 appear feasible, opening the way to a number of potential applications involving distributed power. In the present paper, prior work is briefly reviewed, and the design of a cell employing integrated electrode and solid-state electrical-conversion systems is described along with some recent experimental results. (authors)

  14. Design of a low energy reaction cell for distributed power applications

    Energy Technology Data Exchange (ETDEWEB)

    Miley, G.H.; Castano, C.; Okuniewski, M.; Selvaggi, G.; Lipson, A. [Illinois Univ., Dept. of Nuclear, Plasma and Radiological Engineering, Urbana, IL (United States)

    2001-07-01

    Power units using Low Energy Nuclear Reactions (LENRs) potentially offer a radical new approach to power units that could provide distributed power units in the 1- 50 kW range. As described in an ICONE-8 paper (Miley, et al. 2000-c), these cells employ thin metallic film cathodes (order of 500.10{sup -10} m, using variously Ni, Pd and Ti) with electrolytes such as 0.5-1 molar lithium sulfate in light water. Power densities exceeding 10 W/cc in the films have been achieved. An ultimate goal is to incorporate this thin-film technology into a 'tightly packed' cell design where the film material occupies {approx}20% of the total volume. If this is achieved, power densities of {approx}20 W/cm{sup 3} appear feasible, opening the way to a number of potential applications involving distributed power. In the present paper, prior work is briefly reviewed, and the design of a cell employing integrated electrode and solid-state electrical-conversion systems is described along with some recent experimental results. (authors)

  15. Reaction of long-lived radicals and vitamin C in γ-irradiated mammalian cells and their model system at 295 K. Tunneling reaction in biological system

    International Nuclear Information System (INIS)

    Matsumoto, Takuro; Kumada, Takayuki; Kodama, Seiji; Watanabe, Masami

    1997-01-01

    When golden hamster embryo (GHE) cells or concentrated albumin solution (0.1 kg dm -3 ), that is a model system of cells, is irradiated with γ-rays at 295 K, organic radicals produced can be observed by ESR. The organic radicals survive at both 295 and 310 K for as long as 20 h. The long-lived radicals in GHE cells and the albumin solution react with vitamin C by the rate constants of 0.007 dm 3 mol -1 s -1 and 0.014 dm 3 mol -1 s -1 , respectively. The long-lived radicals in human cells cause gene mutation, which is suppressed by the addition of vitamin C. The isotope effect on the rate constant (κ) for the reaction of the long-lived radicals and vitamin C has been studied in the albumin solution by use of protonated vitamin C and deuterated vitamin C. The isotope effect (κ H /κ D ) was more than 20 ∼ 50 and was interpreted in terms of tunnelling reaction. (author)

  16. Microbial catalysis of redox reactions in concrete cells of nuclear waste repositories: a review and introduction

    International Nuclear Information System (INIS)

    Albrecht, A.; Bertron, A.; Libert, M.

    2012-01-01

    In this paper, we will review the importance of oxy anions in the nuclear industry; their impact together with concrete, steel and organic matter on the redox state in the near field of a waste storage. Particular consideration will be given to the knowledge in relation to alcaliphilic microbial activity in some cases derived from existing natural analogues. Case studies will consider specific redox-sensitive radionuclides in both near surface and deep storage settings. This information will serve as input to two ongoing experimental endeavour dealing with the specific reaction of nitrate reduction by organic matter and/or H 2 in the concrete cells for bituminous waste disposal. It is not possible to predict the evolution in space and time of the various microbial species capable of influencing key processes occurring in concrete-dominated repository systems. It is thus not really possible to predict reaction kinetics controlled by microbial activity. Two approaches are none-the-less useful; a biogeochemical simulation exercise will help tracing the reactionary paths and a mass balance approach reducing uncertainties in regard to the final, possibly equilibrium situation. Both are described here with the goal in mind to syntheses and conclude a subject matter which is at full scientific swing

  17. PTFE effect on the electrocatalysis of the oxygen reduction reaction in membraneless microbial fuel cells.

    Science.gov (United States)

    Guerrini, Edoardo; Grattieri, Matteo; Faggianelli, Alessio; Cristiani, Pierangela; Trasatti, Stefano

    2015-12-01

    Influence of PTFE in the external Gas Diffusion Layer (GDL) of open-air cathodes applied to membraneless microbial fuel cells (MFCs) is investigated in this work. Electrochemical measurements on cathodes with different PTFE contents (200%, 100%, 80% and 60%) were carried out to characterize cathodic oxygen reduction reaction, to study the reaction kinetics. It is demonstrated that ORR is not under diffusion-limiting conditions in the tested systems. Based on cyclic voltammetry, an increase of the cathodic electrochemical active area took place with the decrease of PTFE content. This was not directly related to MFC productivity, but to the cathode wettability and the biocathode development. Low electrodic interface resistances (from 1 to 1.5 Ω at the start, to near 0.1 Ω at day 61) indicated a negligible ohmic drop. A decrease of the Tafel slopes from 120 to 80 mV during productive periods of MFCs followed the biological activity in the whole MFC system. A high PTFE content in the cathode showed a detrimental effect on the MFC productivity, acting as an inhibitor of ORR electrocatalysis in the triple contact zone.

  18. Phase transformations in the reaction cell of TiNi-based sintered systems

    Science.gov (United States)

    Artyukhova, Nadezhda; Anikeev, Sergey; Yasenchuk, Yuriy; Chekalkin, Timofey; Gunther, Victor; Kaftaranova, Maria; Kang, Ji-Hoon; Kim, Ji-Soon

    2018-05-01

    The present work addresses the structural-phase state changes of porous TiNi-based compounds fabricated by reaction sintering (RS) of Ti and Ni powders with Co, Mo, and no additives introduced. The study also emphasizes the features of a reaction cell (RC) during the transition from the solid- to liquid-phase sintering. Mechanisms of phase transformations occurring in the solid phase, involving the low-melting Ti2Ni phase within the RC, have been highlighted. Also, the intermediate Ti2Ni phase had a crucial role to provide both the required RS behavior and modified phase composition of RS samples, and besides, it is found to be responsible for the near-equiatomic TiNi saturation of the melt. Both cobalt and molybdenum additives are shown to cause additional structuring of the transition zone (TZ) at the Ti2Ni‑TiNi interface and broadening of this zone. The impact of Co and Mo on the Ti2Ni phase is evident through fissuring of this phase layer, which is referred to solidified stresses increased in the layer due to post-alloying defects in the structure.

  19. Review on modeling development for multiscale chemical reactions coupled transport phenomena in solid oxide fuel cells

    International Nuclear Information System (INIS)

    Andersson, Martin; Yuan, Jinliang; Sunden, Bengt

    2010-01-01

    A literature study is performed to compile the state-of-the-art, as well as future potential, in SOFC modeling. Principles behind various transport processes such as mass, heat, momentum and charge as well as for electrochemical and internal reforming reactions are described. A deeper investigation is made to find out potentials and challenges using a multiscale approach to model solid oxide fuel cells (SOFCs) and combine the accuracy at microscale with the calculation speed at macroscale to design SOFCs, based on a clear understanding of transport phenomena, chemical reactions and functional requirements. Suitable methods are studied to model SOFCs covering various length scales. Coupling methods between different approaches and length scales by multiscale models are outlined. Multiscale modeling increases the understanding for detailed transport phenomena, and can be used to make a correct decision on the specific design and control of operating conditions. It is expected that the development and production costs will be decreased and the energy efficiency be increased (reducing running cost) as the understanding of complex physical phenomena increases. It is concluded that the connection between numerical modeling and experiments is too rare and also that material parameters in most cases are valid only for standard materials and not for the actual SOFC component microstructures.

  20. Exothermic reactions among components of lithium-sulfur dioxide and lithium-thionyl chloride cells

    Science.gov (United States)

    Dallek, S.; James, S. D.; Kilroy, W. P.

    1981-03-01

    Differential scanning calorimetry measurements were made on various components of Li-SOCl2 cells to identify those combinations that react exothermically and might cause batteries to explode. The passivation of Li by SO2 in acetonitrile (AN) was characterized over a wide range of SO2 concentration (0.1-14M). In the absence of SO2, trace additions of water greatly lower the exothermicity of the Li-AN reaction. The Li-SOCl2-LiAlCl4 mixture is inert over a wide range of temperature well above the melting point of Li. However, adding carbon black converts this inert mixture into one which is highly and consistently reactive. The addition of copper powder enhances carbon's catalytic effect on the reactivity of the Li-SOCl2-LiAlCl4 mixture while trace additions of water have the opposite effect.

  1. Electrocatalytic performance of fuel cell reactions at low catalyst loading and high mass transport.

    Science.gov (United States)

    Zalitis, Christopher M; Kramer, Denis; Kucernak, Anthony R

    2013-03-28

    An alternative approach to the rotating disk electrode (RDE) for characterising fuel cell electrocatalysts is presented. The approach combines high mass transport with a flat, uniform, and homogeneous catalyst deposition process, well suited for studying intrinsic catalyst properties at realistic operating conditions of a polymer electrolyte fuel cell (PEFC). Uniform catalyst layers were produced with loadings as low as 0.16 μgPt cm(-2) and thicknesses as low as 200 nm. Such ultra thin catalyst layers are considered advantageous to minimize internal resistances and mass transport limitations. Geometric current densities as high as 5.7 A cm(-2)Geo were experimentally achieved at a loading of 10.15 μgPt cm(-2) for the hydrogen oxidation reaction (HOR) at room temperature, which is three orders of magnitude higher than current densities achievable with the RDE. Modelling of the associated diffusion field suggests that such high performance is enabled by fast lateral diffusion within the electrode. The electrodes operate over a wide potential range with insignificant mass transport losses, allowing the study of the ORR at high overpotentials. Electrodes produced a specific current density of 31 ± 9 mA cm(-2)Spec at a potential of 0.65 V vs. RHE for the oxygen reduction reaction (ORR) and 600 ± 60 mA cm(-2)Spec for the peak potential of the HOR. The mass activity of a commercial 60 wt% Pt/C catalyst towards the ORR was found to exceed a range of literature PEFC mass activities across the entire potential range. The HOR also revealed fine structure in the limiting current range and an asymptotic current decay for potentials above 0.36 V. These characteristics are not visible with techniques limited by mass transport in aqueous media such as the RDE.

  2. Bacteriological assessment of smoked game meat in Lubumbashi, D.R.C.

    Directory of Open Access Journals (Sweden)

    Kabwang a Mpalang, R.

    2013-01-01

    Full Text Available The bacteriological quality of smoked game meat in Lubumbashi has not been studied much to date. The present study focused on the analysis of 182 samples of smoked game meat from three species, Syncerus caffer (n = 63, Phacochoerus aethiopicus (n = 60 and Sylvicapra grimmia (n = 59, sold at retail outlets in Lubumbashi. The isolation of Escherichia coli from 81.3% of samples (mean 4.87 ± 0.6 log10 CFU·g-1 of sample confirms significant faecal contamination of smoked game meat. The study has determined by culture prevalences of 0.0%, 4.3% [CI95% 1.4-7.4], 3.8% [CI95% 1.1-6.6] and 14.2% [CI95% 9.2-19.4] respectively for Shiga toxigenic Escherichia coli (STEC, Salmonella spp., Campylobacter jejuni and Campylobacter coli. Using Polymerase Chain Reaction, these prevalences were of 2.2% [IC95% 0.1-4.3], 6.0% [IC95% 2.6-9.5], 3.8% [IC95% 1.1-6.6] and 15.9% [IC95% 10.6-21.3] respectively for STEC, Salmonella spp., C. jejuni and C. coli. Syncerus caffer was established as a potential vehicle of STEC carrying stx1 gene (3.2%, stx2 gene (1.6% and the combination of stx2 and eae genes (1.6%. On the basis of these data, we suggested the need for developing monitoring plans of the production, preparation, handling and distribution of smoked game meat in Lubumbashi.

  3. ¹⁹F magnetic resonance probes for live-cell detection of peroxynitrite using an oxidative decarbonylation reaction.

    Science.gov (United States)

    Bruemmer, Kevin J; Merrikhihaghi, Sara; Lollar, Christina T; Morris, Siti Nur Sarah; Bauer, Johannes H; Lippert, Alexander R

    2014-10-21

    We report a newly discovered oxidative decarbonylation reaction of isatins that is selectively mediated by peroxynitrite (ONOO(-)) to provide anthranilic acid derivatives. We have harnessed this rapid and selective transformation to develop two reaction-based probes, 5-fluoroisatin and 6-fluoroisatin, for the low-background readout of ONOO(-) using (19)F magnetic resonance spectroscopy. 5-fluoroisatin was used to non-invasively detect ONOO(-) formation in living lung epithelial cells stimulated with interferon-γ (IFN-γ).

  4. Human bone marrow-derived mesenchymal cell reactions to 316L stainless steel : An in vitro study on cell viability and interleukin-6 expression

    NARCIS (Netherlands)

    Anwar, I.B.; Santoso, A.; Saputra, E.; Ismail, R.; Jamari, J.; van der Heide, E.

    2017-01-01

    Purpose: Human bone marrow-derived mesenchymal cell (hBMC) reactions to 316L stainless steel (316L-SS) have never been evaluated. The objective of this study was to assess cell viability and interleukin-6 expression of hBMC cultures upon treatment with a 316L-SS implant. Methods: A cytotoxicity

  5. Delayed hemolytic transfusion reaction/hyperhemolysis syndrome in children with sickle cell disease.

    Science.gov (United States)

    Talano, Julie-An M; Hillery, Cheryl A; Gottschall, Jerome L; Baylerian, Diane M; Scott, J Paul

    2003-06-01

    Alloimmunization in patients with sickle cell disease (SCD) has a reported incidence of 5% to 36%. One complication of alloimmunization is delayed hemolytic transfusion reaction/hyperhemolysis (DHTR/H) syndrome, which has a reported incidence of 11%. In patients with SCD, clinical findings in DHTR/H syndrome occur approximately 1 week after the red blood cell (RBC) transfusion and include the onset of increased hemolysis associated with pain and profound anemia. The hemoglobin (Hb) often drops below pretransfusion levels. In many reported adult cases, the direct antiglobulin test (DAT) remains negative and no new alloantibody is detected as the cause for these transfusion reactions. To date, few pediatric cases have been reported with this phenomenon. The objective of this study was to describe the clinical and laboratory findings of a case series in children who had SCD and experienced a DHTR/H syndrome at our institution. An 11-year retrospective chart review of patients with discharge diagnosis of SCD and transfusion reaction was performed. DHTR/H syndrome was defined as the abrupt onset of signs and symptoms of accelerated hemolysis evidenced by an unexplained fall in Hb, elevated lactic dehydrogenase, elevated bilirubin above baseline, and hemoglobinuria, all occurring between 4 and 10 days after an RBC transfusion. Patient characteristics, time from transfusion, symptoms, reported DAT, new autoantibody or alloantibody formation, laboratory abnormalities, and complications were recorded. Patients with acute transfusion reactions were excluded. We encountered 7 patients who developed 9 episodes of DHTR/H syndrome occurring 6 to 10 days after RBC transfusion. Each presented with fever and hemoglobinuria. All but 1 patient experienced pain initially ascribed to vaso-occlusive crisis. The DAT was positive in only 2 of the 9 episodes. The presenting Hb was lower than pretransfusion levels in 8 of the 9 events. Severe complications were observed after the onset of

  6. Electrode Reaction Pathway in Oxide Anode for Solid Oxide Fuel Cells

    Science.gov (United States)

    Li, Wenyuan

    Oxide anodes for solid oxide fuel cells (SOFC) with the advantage of fuel flexibility, resistance to coarsening, small chemical expansion and etc. have been attracting increasing interest. Good performance has been reported with a few of perovskite structure anodes, such as (LaSr)(CrMn)O3. However, more improvements need to be made before meeting the application requirement. Understanding the oxidation mechanism is crucial for a directed optimization, but it is still on the early stage of investigation. In this study, reaction mechanism of oxide anodes is investigated on doped YCrO 3 with H2 fuel, in terms of the origin of electrochemical activity, rate-determining steps (RDS), extension of reactive zone, and the impact from overpotential under service condition to those properties. H2 oxidation on the YCs anodes is found to be limited by charge transfer and H surface diffusion. A model is presented to describe the elementary steps in H2 oxidation. From the reaction order results, it is suggested that any models without taking H into the charge transfer step are invalid. The nature of B site element determines the H2 oxidation kinetics primarily. Ni displays better adsorption ability than Co. However, H adsorption ability of such oxide anode is inferior to that of Ni metal anode. In addition, the charge transfer step is directly associated with the activity of electrons in the anode; therefore it can be significantly promoted by enhancement of the electron activity. It is found that A site Ca doping improves the polarization resistance about 10 times, by increasing the activity of electrons to promote the charge transfer process. For the active area in the oxide anode, besides the traditional three-phase boundary (3PB), the internal anode surface as two-phase boundary (2PB) is proven to be capable of catalytically oxidizing the H2 fuel also when the bulk lattice is activated depending on the B site elements. The contribution from each part is estimated by switching

  7. Progress in Development of a Low Energy Reaction Cell for Distributed Power Applications

    International Nuclear Information System (INIS)

    Miley, G.H.; Castano, C.; Lipson, A.; Kim, S.O.; Luo, N.

    2002-01-01

    Power units using Low Energy Nuclear Reactions (LENRs) potentially offer a radical new approach to power units that could provide distributed power units in the 1-50 kW range. As described in prior ICONE papers [9, 23] these cells employ thin metallic film cathodes (order of 500 Angstrom, using variously Ni, Pd and Ti) with electrolytes such as 0.5-1 molar lithium sulfates in light water. Power densities exceeding 10 W/cc in the films have been achieved. An ultimate goal is to incorporate this thin-film technology into a 'tightly packed' cell design where the film material occupies ∼20% of the total volume. If this is achieved, power densities of ∼20 W/cm 3 appear feasible, opening the way to a number of potential applications involving distributed power. Recent studies reported here have concentrated on new electrode designs intended to maximize the proton loading in the films while maintaining the required proton and electron current densities. (authors)

  8. A reaction cell with sample laser heating for in situ soft X-ray absorption spectroscopy studies under environmental conditions.

    Science.gov (United States)

    Escudero, Carlos; Jiang, Peng; Pach, Elzbieta; Borondics, Ferenc; West, Mark W; Tuxen, Anders; Chintapalli, Mahati; Carenco, Sophie; Guo, Jinghua; Salmeron, Miquel

    2013-05-01

    A miniature (1 ml volume) reaction cell with transparent X-ray windows and laser heating of the sample has been designed to conduct X-ray absorption spectroscopy studies of materials in the presence of gases at atmospheric pressures. Heating by laser solves the problems associated with the presence of reactive gases interacting with hot filaments used in resistive heating methods. It also facilitates collection of a small total electron yield signal by eliminating interference with heating current leakage and ground loops. The excellent operation of the cell is demonstrated with examples of CO and H2 Fischer-Tropsch reactions on Co nanoparticles.

  9. An integrated high temperature environmental cell for atom probe tomography studies of gas-surface reactions: Instrumentation and results

    International Nuclear Information System (INIS)

    Dumpala, S.; Broderick, S.R.; Bagot, P.A.J.; Rajan, K.

    2014-01-01

    An integrated environmental cell has been designed and developed for the latest generation of Atom Probe Tomography LEAP™ instruments, allowing controlled exposure of samples to gases at high temperatures. Following treatment, samples can be transferred through the LEAP vacuum system for subsequent APT analysis, which provides detailed information on changes to chemical microstructures following the reactions with near-atomic resolution. A full description of the cell is presented, along with some sample results on the oxidation of aluminum and two platinum-group alloys, demonstrating the capability of combining exposure/characterization functionality in a single instrument. - Highlights: • Designed and built atom probe environmental cell for in situ reactions. • Investigated Al oxidation, and demonstrated improvement with new cell. • in situ APT analysis of Pt-alloys showed surface segregation of Rh and Ir

  10. Effect of cell density and HLA-DR incompatibility on T-cell proliferation and forkhead box P3 expression in human mixed lymphocyte reaction.

    Science.gov (United States)

    Song, E Y; Han, S; Yang, B; Morris, G P; Bui, J D

    2015-04-01

    The proliferation rates of human T cells in vitro are affected by some factors such as initial T-cell number, dose of stimulating cells, and duration of culture. The transcription factor forkhead box P3 (FoxP3) has been used to identify regulatory T cells in humans and is thought to correlate with tolerance to allogeneic organ transplant. Thus, it is important to optimize conditions to expand FoxP3 cell proliferation to improve engraftment of allogeneic organ transplants. We studied proliferative responses and FoxP3 expression in divided T cells with the use of flow cytometric analysis of Ki-67 in culture of different concentrations of responding cells (6 × 10(6), 4 × 10(6), 2 × 10(6), 1 × 10(6), and 0.5 × 10(6)cells/mL), different types of stimulating cells (lymphocytes and low density cells), and different numbers of HLA mismatches. The proportion of CD3(+) cells, CD4(+)CD25(+) cells, and CD4(+)CD25(+)FoxP3(+) cells among mononuclear cells were highest at initial cell concentration of 2 × 10(6) responder cells/mL with lymphocytes as stimulators at day-5 mixed lymphocyte reaction (MLR). They were highest at a concentration of 4 × 10(6) responder cells/mL with low density cells as stimulators. The recovery (%), proportion of CD3(+) cells, CD4(+)CD25(+) cells, and CD4(+)CD25(+)FoxP3(+) cells with 2 HLA-DR incompatibility were significantly higher than those of 1 HLA-DR incompatibility at day-5 MLR. Initial cell concentration and HLA-DR incompatibility can affect the generation of FoxP3+ T cells in human MLR. These factors could be considered for efficient generation of Tregs for clinical trials in the future. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Electrochemical reaction rates in a dye-sensitised solar cell - the iodide/tri-iodide redox system

    DEFF Research Database (Denmark)

    Bay, L.; West, K.; Winther-Jensen, B.

    2006-01-01

    The electrochemical reaction rate of the redox couple iodide/tri-iodide in acetonitrile is characterised by impedance spectroscopy. Different electrode materials relevant for the function of dye-sensitised solar cells (DSSC) are investigated. Preferably, the reaction with the iodide....../tri-iodide couple should be fast at the counter electrode, i.e. this electrode must have a high catalytic activity towards the redox couple, and the same reaction must be slow on the photo electrode. The catalytic activity is investigated for platinum, poly(3,4-ethylenedioxythiophene) (PEDOT), polypyrrole (PPy......), and polyaniline (PANI)-all deposited onto fluorine-doped tin oxide (FTO) glass. Both Pt and PEDOT are found to have sufficiently high catalytic activities for practical use as counter electrodes in DSSC. The reaction resistance on FTO and anatase confirmed the beneficial effect of a compact anatase layer on top...

  12. Delayed hemolytic transfusion reaction presenting as a painful crisis in a patient with sickle cell anemia.

    Science.gov (United States)

    Fabron, A; Moreira, G; Bordin, J O

    1999-01-07

    Patients with sickle cell anemia (SCA) are frequently transfused with red blood cells (RBC). Recently we reported that the calculated risk of RBC alloimmunization per transfussed unit in Brazilian patients with SCA is 1.15%. We describe a delayed hemolytic transfusion reaction (DHTR) presenting as a painful crisis in a patient with SCA. A 35-year-old Brazilian female with homozygous SCA was admitted for a program of partial exchange transfusion prior to cholecystectomy. Her blood group was O RhD positive and no atypical RBC alloantibody was detected using the indirect antiglobulin technique. Pre-transfusional hemoglobin (Hb) was 8.7 g/dL and isovolumic partial exchange transfusion was performed using 4 units of ABO compatible packed RBC. Five days after the last transfusion she developed generalized joint pain and fever of 39 degrees C. Her Hb level dropped from 12.0 g/dL to 9.3 g/dL and the unconjugated bilirrubin level rose to 27 mmol/L. She was jaundiced and had hemoglobinuria. Hemoglobin electrophoresis showed 48.7% HbS, 46.6% HbA1, 2.7% HbA2, and 2.0% HbF. The patient's extended RBC phenotype was CDe, K-k+, Kp(a-b+), Fy(a-b-), M+N+s+, Le(a+b-), Di(a-). An RBC alloantibody with specificity to the Rh system (anti-c, titer 1:16.384) was identified by the indirect antiglobulin test. The Rh phenotype of the RBC used in the last packed RBC transfusion was CcDEe. The patient was discharged, asymptomatic, 7 days after admission.

  13. Skin Reactions and Quality of Life after X-Ray Therapy of Basal Cell Carcinoma

    International Nuclear Information System (INIS)

    Skiveren, J.; Daugbjerg, H.; Wulf, H. C.; Mikkelsen, M. R.

    2012-01-01

    Background. Advanced basal cell carcinoma (BCC) is often treated by surgery or X-ray therapy. The consequences of X-ray therapy on the patients health-related quality-of-life (HRQOL) have so far not been described. Objectives. To quantify quality of life in BCC patients before and after X-ray therapy compared with matched healthy controls. Materials. Twenty-five patients (mean age 69) with BCC completed the Dermatology Life Quality Index (DLQI) before and two weeks and three months after X-ray therapy and their results were compared with the DLQI scores for 25 matched controls. Results. Compared to the healthy controls the patients' DLQI score was significantly higher before and 2 weeks after X-ray therapy ( ρ=0.005;ρ=0.000). The patients' DLQI score decreased significantly from baseline to three months after X-ray therapy (ρ=0.024), when it became similar to that of the healthy controls (ρ=0.819). Three months after X-ray therapy eight patients had no skin reactions, 11 had slight atrophy, pigmentation change, and/or some hair loss, four had patch atrophy, moderate telangiectasia, and/or total hair loss. Conclusions. BCC has a negative effect on patients' quality of life. The study shows that HRQOL normalises shortly after X-ray therapy, despite minor skin manifestations.

  14. Platinum Group Metal-free Catalysts for Hydrogen Evolution Reaction in Microbial Electrolysis Cells.

    Science.gov (United States)

    Yuan, Heyang; He, Zhen

    2017-07-01

    Hydrogen gas is a green energy carrier with great environmental benefits. Microbial electrolysis cells (MECs) can convert low-grade organic matter to hydrogen gas with low energy consumption and have gained a growing interest in the past decade. Cathode catalysts for the hydrogen evolution reaction (HER) present a major challenge for the development and future applications of MECs. An ideal cathode catalyst should be catalytically active, simple to synthesize, durable in a complex environment, and cost-effective. A variety of noble-metal free catalysts have been developed and investigated for HER in MECs, including Nickel and its alloys, MoS 2 , carbon-based catalysts and biocatalysts. MECs in turn can serve as a research platform to study the durability of the HER catalysts. This personal account has reviewed, analyzed, and discussed those catalysts with an emphasis on synthesis and modification, system performance and potential for practical applications. It is expected to provide insights into the development of HER catalysts towards MEC applications. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. A reaction cell for ambient pressure soft x-ray absorption spectroscopy

    Science.gov (United States)

    Castán-Guerrero, C.; Krizmancic, D.; Bonanni, V.; Edla, R.; Deluisa, A.; Salvador, F.; Rossi, G.; Panaccione, G.; Torelli, P.

    2018-05-01

    We present a new experimental setup for performing X-ray Absorption Spectroscopy (XAS) in the soft X-ray range at ambient pressure. The ambient pressure XAS setup is fully compatible with the ultra high vacuum environment of a synchrotron radiation spectroscopy beamline end station by means of ultrathin Si3N4 membranes acting as windows for the X-ray beam and seal of the atmospheric sample environment. The XAS detection is performed in total electron yield (TEY) mode by probing the drain current from the sample with a picoammeter. The high signal/noise ratio achievable in the TEY mode, combined with a continuous scanning of the X-ray energies, makes it possible recording XAS spectra in a few seconds. The first results show the performance of this setup to record fast XAS spectra from sample surfaces exposed at atmospheric pressure, even in the case of highly insulating samples. The use of a permanent magnet inside the reaction cell enables the measurement of X-ray magnetic circular dichroism at ambient pressure.

  16. Membrane Nanotubes between peritoneal mesothelial cells: functional connectivity and crucial participation during inflammatory reactions

    Directory of Open Access Journals (Sweden)

    Julia eRanzinger

    2014-10-01

    Full Text Available Peritoneal dialysis (PD has attained increased relevance as continuous renal replacement therapy over the past years. During this treatment, the peritoneum functions as dialysis membrane to eliminate diffusible waste products from the blood-stream. Success and efficacy of this treatment is dependent on the integrity of the peritoneal membrane. Chronic inflammatory conditions within the peritoneal cavity coincide with elevated levels of proinflammatory cytokines leading to the impairment of tissue integrity. High glucose concentrations and glucose metabolites in PD solutions contribute to structural and functional reorganization processes of the peritoneal membrane during long-term PD. The subsequent loss of ultrafiltration is causal for the treatment failure over time. It was shown that peritoneal mesothelial cells are functionally connected via Nanotubes (NTs and that a correlation of NT-occurrence and defined pathophysiological conditions exists. Additionally, an important participation of NTs during inflammatory reactions was shown. Here, we will summarize recent developments of NT-related research and provide new insights into NT-mediated cellular interactions under physiological as well as pathophysiological conditions.

  17. Maillard reaction products from highly heated food prevent mast cell number increase and inflammation in a mouse model of colitis.

    Science.gov (United States)

    Al Amir, Issam; Dubayle, David; Héron, Anne; Delayre-Orthez, Carine; Anton, Pauline M

    2017-12-01

    Links between food and inflammatory bowel diseases (IBDs) are often suggested, but the role of food processing has not been extensively studied. Heat treatment is known to cause the loss of nutrients and the appearance of neoformed compounds such as Maillard reaction products. Their involvement in gut inflammation is equivocal, as some may have proinflammatory effects, whereas other seem to be protective. As IBDs are associated with the recruitment of immune cells, including mast cells, we raised the hypothesis that dietary Maillard reaction products generated through heat treatment of food may limit the colitic response and its associated recruitment of mast cells. An experimental model of colitis was used in mice submitted to mildly and highly heated rodent food. Adult male mice were divided in 3 groups and received nonheated, mildly heated, or highly heated chow during 21 days. In the last week of the study, each group was split into 2 subgroups, submitted or not (controls) to dextran sulfate sodium (DSS) colitis. Weight variations, macroscopic lesions, colonic myeloperoxidase activity, and mucosal mast cell number were evaluated at the end of the experiment. Only highly heated chow significantly prevented DSS-induced weight loss, myeloperoxidase activity, and mast cell number increase in the colonic mucosa of DSS-colitic mice. We suggest that Maillard reaction products from highly heated food may limit the occurrence of inflammatory phases in IBD patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. A cell for extended x-ray absorption fine structure studies of oxygen sensitive products of redox reactions

    International Nuclear Information System (INIS)

    Furenlid, L.R.; Renner, M.W.; Fajer, J.

    1990-01-01

    We describe a cell suitable for extended x-ray absorption fine structure (EXAFS) studies of oxygen and/or water sensitive products of redox reactions. The cell utilizes aluminized Mylar windows that are transparent to x rays, provide low gas permeability, and allow vacuum to be maintained in the cell. The windows are attached to the glassware with an epoxy that resists attack by common organic solvents. Additional side arms allow multiple spectroscopic probes of the same sample under anaerobic and anhydrous conditions

  19. Modelling and simulation of a direct ethanol fuel cell considering multistep electrochemical reactions, transport processes and mixed potentials

    International Nuclear Information System (INIS)

    Meyer, Marco; Melke, Julia; Gerteisen, Dietmar

    2011-01-01

    Highlights: → A DEFC model considering the mixed potential formation at cathode and anode. → The low cell voltage at open circuit is due to the parasitic reaction of ethanol and oxygen. → Under load, only the parasitic oxidation of ethanol is significant. → Inhibiting the parasitic reactions can approximately double the current density. - Abstract: In this work a one-dimensional mathematical model of a direct ethanol fuel cell (DEFC) is presented. The electrochemical oxidation of ethanol in the catalyst layers is described by several reaction steps leading to surface coverage with adsorbed intermediates (CH 3 CO, CO, CH 3 and OH) and to the final products acetaldehyde, acetic acid and CO 2 . A bifunctional reaction mechanism is assumed for the activation of water on a binary catalyst favouring the further oxidation of adsorbates blocking active catalyst sites. The chemical reactions are highly coupled with the charge and reactant transport. The model accounts for crossover of the reactants through the membrane leading to the phenomenon of cathode and anode mixed potentials due to the parasitic oxidation and reduction of ethanol and oxygen, respectively. Polarisation curves of a DEFC were recorded for various ethanol feed concentrations and were used as reference data for the simulation. Based on one set of model parameters the characteristic of electronic and protonic potential, the relative surface coverage and the parasitic current densities in the catalyst layers were studied.

  20. Allosuppression of B cells in vitro by graft-vs.-host reaction-derived T cells is caused by cytotoxic T lymphocytes

    NARCIS (Netherlands)

    Rozendaal, L.; Pals, S. T.; Schilham, M.; Melief, C. J.; Gleichmann, E.

    1989-01-01

    An acute graft-vs.-host reaction (GVHR) was induced by i.v. injection of 10(8) lymphoid cells from C57BL/10 (B10) donors (H-2b/b) into adult non-irradiated (B10 X DBA/2)F1 mice (H-2b/d). Previous experiments have established that spleen cells obtained from such GVHF1 mice suppress the primary

  1. Paraneoplastic scleroderma-like tissue reactions in the setting of an underlying plasma cell dyscrasia: a report of 10 cases.

    Science.gov (United States)

    Magro, Cynthia M; Iwenofu, Hans; Nuovo, Gerard J

    2013-07-01

    Systemic plasma cell dyscrasias have diverse manifestations in the skin and include an inflammatory paraneoplastic process. We encountered cases of scleroderma and eosinophilic fasciitis in the setting of an underlying plasma cell dyscrasia. Ten cases of scleroderma-like tissue reactions in the setting of an underlying plasma cell dyscrasia were encountered. The biopsies were stained for Transforming growth factor (Transforming growth factor) beta, IgG4, kappa, and lambda. Patients presented with a sclerodermoid reaction represented by eosinophilic fasciitis (5 cases), morphea (3 cases), and systemic scleroderma (2 cases). The mean age of presentation was 70 years with a striking female predominance (4:1). Acral accentuation was noted in 8 cases. In 6 of the cases, the cutaneous sclerosis antedated (4 cases) by weeks to 2 years or occurred concurrently (2 cases) with the initial diagnosis of the plasma cell. The biopsies showed changes typical of eosinophilic fasciitis and/or scleroderma. In 5 cases, light chain-restricted plasma cells were present on the biopsy. There was staining of the plasma cells for Transforming growth factor beta in 3 out of 5 cases tested. In any older patient presenting with a sudden onset of eosinophilic fasciitis or scleroderma especially with acral accentuation, investigations should be conducted in regards to an underlying plasma cell dyscrasia.

  2. The Oxford-Diamond In Situ Cell for studying chemical reactions using time-resolved X-ray diffraction

    Science.gov (United States)

    Moorhouse, Saul J.; Vranješ, Nenad; Jupe, Andrew; Drakopoulos, Michael; O'Hare, Dermot

    2012-08-01

    A versatile, infrared-heated, chemical reaction cell has been assembled and commissioned for the in situ study of a range of chemical syntheses using time-resolved energy-dispersive X-ray diffraction (EDXRD) on Beamline I12 at the Diamond Light Source. Specialized reactor configurations have been constructed to enable in situ EDXRD investigation of samples under non-ambient conditions. Chemical reactions can be studied using a range of sample vessels such as alumina crucibles, steel hydrothermal autoclaves, and glassy carbon tubes, at temperatures up to 1200 °C.

  3. Implementing DDR in Settings of Ongoing Conflict: The Organization and Fragmentation of Armed Groups in the Democratic Republic of Congo (DRC

    Directory of Open Access Journals (Sweden)

    Joanne Richards

    2016-09-01

    Full Text Available Although it is common for armed groups to splinter (or “fragment” during contexts of multi-party civil war, current guidance on Disarmament, Demobilization, and Reintegration (DDR does not address the challenges that arise when recalcitrant fighters, unwilling to report to DDR, break ranks and form new armed groups. This Practice Note addresses this issue, drawing lessons from the multi-party context of the DRC and from the experiences of former members of three armed groups: the Rally for Congolese Democracy-Goma (RCD-Goma, the National Congress for the Defense of the People (CNDP, and the DRC national army (FARDC. While the findings indicate that the fragmentation of armed groups may encourage desertion and subsequent participation in DDR, they also show that active armed groups may monitor DDR programs and track those who demobilize. Remobilization may follow, either as active armed groups target ex-combatants for forced re-recruitment or as ex-combatants remobilize in armed groups of their own choice. Given these dynamics, practitioners in settings of partial peace may find it useful to consider non-traditional methods of DDR such as the use of mobile patrols and mobile disarmament units. The temporary relocation of ex-combatants to safe areas free from armed groups, or to protected transitional assistance camps, may also help to minimize remobilization during the reintegration phase.

  4. Field and laboratory emission cell automation and control system for investigating surface chemistry reactions

    Science.gov (United States)

    Flemmer, Michael M.; Ham, Jason E.; Wells, J. R.

    2007-01-01

    A novel system [field and laboratory emission cell (FLEC) automation and control system] has been developed to deliver ozone to a surface utilizing the FLEC to simulate indoor surface chemistry. Ozone, humidity, and air flow rate to the surface were continuously monitored using an ultraviolet ozone monitor, humidity, and flow sensors. Data from these sensors were used as feedback for system control to maintain predetermined experimental parameters. The system was used to investigate the chemistry of ozone with α-terpineol on a vinyl surface over 72h. Keeping all other experimental parameters the same, volatile organic compound emissions from the vinyl tile with α-terpineol were collected from both zero and 100ppb(partsper109) ozone exposures. System stability profiles collected from sensor data indicated experimental parameters were maintained to within a few percent of initial settings. Ozone data from eight experiments at 100ppb (over 339h) provided a pooled standard deviation of 1.65ppb and a 95% tolerance of 3.3ppb. Humidity data from 17 experiments at 50% relative humidity (over 664h) provided a pooled standard deviation of 1.38% and a 95% tolerance of 2.77%. Data of the flow rate of air flowing through the FLEC from 14 experiments at 300ml/min (over 548h) provided a pooled standard deviation of 3.02ml/min and a 95% tolerance range of 6.03ml/min. Initial experimental results yielded long term emissions of ozone/α-terpineol reaction products, suggesting that surface chemistry could play an important role in indoor environments.

  5. Human atopic dermatitis skin-derived T cells can induce a reaction in mouse keratinocytes in vivo

    DEFF Research Database (Denmark)

    Martel, Britta C; Blom, Lars; Dyring-Andersen, Beatrice

    2015-01-01

    . In comparison, blood -derived in vitro differentiated Th2 cells only induced a weak response in a few of the mice. Thus, we conclude that human AD skin-derived T cells can induce a reaction in mouse skin through induction of a proliferative response in the mouse keratinocytes. This article is protected......In atopic dermatitis (AD), the inflammatory response between skin infiltrating T cells and keratinocytes is fundamental to the development of chronic lesional eczema. The aim of this study was to investigate whether skin-derived T cells from AD patients could induce an inflammatory response in mice...... through keratinocyte activation and consequently cause development of eczematous lesions. Punch biopsies of lesional skin from AD patients were used to establish skin-derived T cell cultures and which were transferred into NOD.Cg-Prkd(scid) Il2rg(tm1Sug) /JicTac (NOG) mice. We found that subcutaneous...

  6. Comparison of reverse transcription-quantitative polymerase chain reaction methods and platforms for single cell gene expression analysis.

    Science.gov (United States)

    Fox, Bridget C; Devonshire, Alison S; Baradez, Marc-Olivier; Marshall, Damian; Foy, Carole A

    2012-08-15

    Single cell gene expression analysis can provide insights into development and disease progression by profiling individual cellular responses as opposed to reporting the global average of a population. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) is the "gold standard" for the quantification of gene expression levels; however, the technical performance of kits and platforms aimed at single cell analysis has not been fully defined in terms of sensitivity and assay comparability. We compared three kits using purification columns (PicoPure) or direct lysis (CellsDirect and Cells-to-CT) combined with a one- or two-step RT-qPCR approach using dilutions of cells and RNA standards to the single cell level. Single cell-level messenger RNA (mRNA) analysis was possible using all three methods, although the precision, linearity, and effect of lysis buffer and cell background differed depending on the approach used. The impact of using a microfluidic qPCR platform versus a standard instrument was investigated for potential variability introduced by preamplification of template or scaling down of the qPCR to nanoliter volumes using laser-dissected single cell samples. The two approaches were found to be comparable. These studies show that accurate gene expression analysis is achievable at the single cell level and highlight the importance of well-validated experimental procedures for low-level mRNA analysis. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Advanced Precursor Reaction Processing for Cu(InGa)(SeS)2 Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Shafarman, William N. [Univ. of Delaware, Newark, DE (United States)

    2015-10-12

    This project “Advanced Precursor Reaction Processing for Cu(InGa)(SeS)2 Solar Cells”, completed by the Institute of Energy Conversion (IEC) at the University of Delaware in collaboration with the Department of Chemical Engineering at the University of Florida, developed the fundamental understanding and technology to increase module efficiency and improve the manufacturability of Cu(InGa)(SeS)2 films using the precursor reaction approach currently being developed by a number of companies. Key results included: (1) development of a three-step H2Se/Ar/H2S reaction process to control Ga distribution through the film and minimizes back contact MoSe2 formation; (2) Ag-alloying to improve precursor homogeneity by avoiding In phase agglomeration, faster reaction and improved adhesion to allow wider reaction process window; (3) addition of Sb, Bi, and Te interlayers at the Mo/precursor junction to produce more uniform precursor morphology and improve adhesion with reduced void formation in reacted films; (4) a precursor structure containing Se and a reaction process to reduce processing time to 5 minutes and eliminate H2Se usage, thereby increasing throughput and reducing costs. All these results were supported by detailed characterization of the film growth, reaction pathways, thermodynamic assessment and device behavior.

  8. Rapid acquisition and model-based analysis of cell-free transcription–translation reactions from nonmodel bacteria

    Science.gov (United States)

    Wienecke, Sarah; Ishwarbhai, Alka; Tsipa, Argyro; Aw, Rochelle; Kylilis, Nicolas; Bell, David J.; McClymont, David W.; Jensen, Kirsten; Biedendieck, Rebekka

    2018-01-01

    Native cell-free transcription–translation systems offer a rapid route to characterize the regulatory elements (promoters, transcription factors) for gene expression from nonmodel microbial hosts, which can be difficult to assess through traditional in vivo approaches. One such host, Bacillus megaterium, is a giant Gram-positive bacterium with potential biotechnology applications, although many of its regulatory elements remain uncharacterized. Here, we have developed a rapid automated platform for measuring and modeling in vitro cell-free reactions and have applied this to B. megaterium to quantify a range of ribosome binding site variants and previously uncharacterized endogenous constitutive and inducible promoters. To provide quantitative models for cell-free systems, we have also applied a Bayesian approach to infer ordinary differential equation model parameters by simultaneously using time-course data from multiple experimental conditions. Using this modeling framework, we were able to infer previously unknown transcription factor binding affinities and quantify the sharing of cell-free transcription–translation resources (energy, ribosomes, RNA polymerases, nucleotides, and amino acids) using a promoter competition experiment. This allows insights into resource limiting-factors in batch cell-free synthesis mode. Our combined automated and modeling platform allows for the rapid acquisition and model-based analysis of cell-free transcription–translation data from uncharacterized microbial cell hosts, as well as resource competition within cell-free systems, which potentially can be applied to a range of cell-free synthetic biology and biotechnology applications. PMID:29666238

  9. Investigation of chemical and electrochemical reactions mechanisms in a direct carbon fuel cell using olive wood charcoal as sustainable fuel

    Science.gov (United States)

    Elleuch, Amal; Halouani, Kamel; Li, Yongdan

    2015-05-01

    Direct carbon fuel cell (DCFC) is a high temperature fuel cell using solid carbon as fuel. The use of environmentally friendly carbon material constitutes a promising option for the DCFC future. In this context, this paper focuses on the use of biomass-derived charcoal renewable fuel. A practical investigation of Tunisian olive wood charcoal (OW-C) in planar DCFCs is conducted and good power density (105 mW cm-2) and higher current density (550 mA cm-2) are obtained at 700 °C. Analytical and predictive techniques are performed to explore the relationships between fuel properties and DCFC chemical and electrochemical mechanisms. High carbon content, carbon-oxygen groups and disordered structure, are the key parameters allowing the achieved good performance. Relatively complex chain reactions are predicted to explain the gas evolution within the anode. CO, H2 and CH4 participation in the anodic reaction is proved.

  10. Reversible logic gates based on enzyme-biocatalyzed reactions and realized in flow cells: a modular approach.

    Science.gov (United States)

    Fratto, Brian E; Katz, Evgeny

    2015-05-18

    Reversible logic gates, such as the double Feynman gate, Toffoli gate and Peres gate, with 3-input/3-output channels are realized using reactions biocatalyzed with enzymes and performed in flow systems. The flow devices are constructed using a modular approach, where each flow cell is modified with one enzyme that biocatalyzes one chemical reaction. The multi-step processes mimicking the reversible logic gates are organized by combining the biocatalytic cells in different networks. This work emphasizes logical but not physical reversibility of the constructed systems. Their advantages and disadvantages are discussed and potential use in biosensing systems, rather than in computing devices, is suggested. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Hydrogen Oxidation Reaction at the Ni/YSZ Anode of Solid Oxide Fuel Cells from First Principles

    Science.gov (United States)

    Cucinotta, Clotilde S.; Bernasconi, Marco; Parrinello, Michele

    2011-11-01

    By means of ab initio simulations we here provide a comprehensive scenario for hydrogen oxidation reactions at the Ni/zirconia anode of solid oxide fuel cells. The simulations have also revealed that in the presence of water chemisorbed at the oxide surface, the active region for H oxidation actually extends beyond the metal/zirconia interface unraveling the role of water partial pressure in the decrease of the polarization resistance observed experimentally.

  12. A Finite Strain Model of Stress, Diffusion, Plastic Flow and Electrochemical Reactions in a Lithium-ion Half-cell

    OpenAIRE

    Bower, Allan F.; Guduru, Pradeep R.; Sethuraman, Vijay A.

    2011-01-01

    We formulate the continuum field equations and constitutive equations that govern deformation, stress, and electric current flow in a Li-ion half-cell. The model considers mass transport through the system, deformation and stress in the anode and cathode, electrostatic fields, as well as the electrochemical reactions at the electrode/electrolyte interfaces. It extends existing analyses by accounting for the effects of finite strains and plastic flow in the electrodes, and by exploring in deta...

  13. Quantitative imaging of glutathione in live cells using a reversible reaction-based ratiometric fluorescent probe

    Science.gov (United States)

    Glutathione (GSH) plays an important role in maintaining redox homeostasis inside cells. Currently, there are no methods available to quantitatively assess the GSH concentration in live cells. Live cell fluorescence imaging revolutionized the understanding of cell biology and has become an indispens...

  14. Detection of Clostridium botulinum type C cells in the gastrointestinal tracts of Mozambique tilapia (Oreochromis mossambicus) by polymerase chain reaction

    Science.gov (United States)

    Nol, P.; Williamson, J.L.; Rocke, T.E.; Yuill, Thomas M.

    2004-01-01

    We established a method of directly detecting Clostridium botulinum type C cells, while minimizing spore detection, in the intestinal contents of Mozambique tilapia (Oreochromis mossambicus). This technique involved extraction of predominantly cellular DNA from tilapia intestinal tracts and used a polymerase chain reaction assay to detect presence of type C1 toxin gene. We consistently detected C. botulinum type C cells in tilapia gastrointestinal contents at a level of 7.5×104 cells per 0.25 g material or 1.9×103 cells. This technique is useful for determining prevalence of the potentially active organisms within a given population of fish and may be adapted to other types of C. botulinum and vertebrate populations as well.

  15. Spermatozoa of the shrew, Suncus murinus, undergo the acrosome reaction and then selectively kill cells in penetrating the cumulus oophorus.

    Science.gov (United States)

    Kaneko, T; Iida, H; Bedford, J M; Mōri, T

    2001-08-01

    In the musk shrew, Suncus murinus (and other shrews), the cumulus oophorus is ovulated as a discrete, compact, matrix-free ball of cells linked by specialized junctions. In examining how they penetrate the cumulus, Suncus spermatozoa were observed to first bind consistently by the ventral face over the acrosomal region to the exposed smooth surface of a peripheral cumulus cell. This was apparently followed by point fusions between the plasma and outer acrosomal membranes. Thereafter, spermatozoa without acrosomes were observed within cumulus cells that displayed signs of necrosis, as did some radially neighboring cumulus cells linked by zona adherens and gap junctions. Eventually, penetration of spermatozoa as far as the perizonal space around the zona pellucida left linear tracks of locally necrotic cells flanked by normal cumulus cells. Based on these and previous observations, we conclude that the acrosome reaction in Suncus is always induced by cumulus cells, and that reacted spermatozoa penetrate the cumulus by selective invasion and killing of cumulus cells along a linear track. Loss of the acrosome also exposes an apical body/perforatorium that is covered with barbs that appear to assist reacted fertilizing spermatozoa in binding to the zona pellucida. Because fertilized eggs displayed no other spermatozoa within or bound to the zona, an efficient block to polyspermy must prevent such binding of additional spermatozoa.

  16. Tibial stress reaction presenting as bilateral shin pain in a man taking denosumab for giant cell tumor of the bone.

    Science.gov (United States)

    Lim, Sian Yik; Rastalsky, Naina; Choy, Edwin; Bolster, Marcy B

    2015-12-01

    Prolonged bisphosphonate use has been associated with increased risk of atypical femoral fractures. Very few cases of atypical femoral fractures have been reported with denosumab. We report a case of bilateral tibial stress reactions in a 60-year-old man with no history of osteoporosis who was on prolonged high-dose denosumab for the treatment of giant cell tumor of bone. He presented with a 3-month history of pain in his bilateral shins worsening with activity and improving with rest. Although initial radiographs were unremarkable, he was found to have changes consistent with a stress reaction on magnetic resonance imaging of the distal tibia. To our knowledge, bilateral tibial stress reactions have not been previously reported with anti-resorptive therapies (neither bisphosphonates nor denosumab). Our case is intriguing in terms of the development of stress reactions as a precursor to stress fractures which may also relate to atypical fractures. Our case suggests a possible association between denosumab use and stress reactions. Of note the indication for denosumab in our case was for the treatment of giant cell tumor of bone where the Food and Drug Administration (FDA) approved dose is substantially higher than the FDA approved dose for osteoporosis treatment. Although rare, clinicians should consider the possibility of stress fractures in patients on anti-resorptive medications such as denosumab, especially when a patient presents with new onset thigh pain, hip pain or pain over an area affecting the long bones. Evaluation by imaging of affected areas should be pursued to enable early detection and intervention, as well as prevention of morbidity and associated ongoing risk to the patient. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Analysis of transport phenomena and electrochemical reactions in a micro PEM fuel cell

    OpenAIRE

    Maher A.R. Sadiq Al-Baghdadi

    2014-01-01

    Micro-fuel cells are considered as promising electrochemical power sources in portable electronic devices. The presence of microelectromechanical system (MEMS) technology makes it possible to manufacture the miniaturized fuel cell systems. The majority of research on micro-scale fuel cells is aimed at micro-power applications. Performance of micro-fuel cells are closely related to many factors, such as designs and operating conditions. CFD modeling and simulation for heat and mass transport i...

  18. Monodisperse Picoliter Droplets for Low-Bias and Contamination-Free Reactions in Single-Cell Whole Genome Amplification.

    Directory of Open Access Journals (Sweden)

    Yohei Nishikawa

    Full Text Available Whole genome amplification (WGA is essential for obtaining genome sequences from single bacterial cells because the quantity of template DNA contained in a single cell is very low. Multiple displacement amplification (MDA, using Phi29 DNA polymerase and random primers, is the most widely used method for single-cell WGA. However, single-cell MDA usually results in uneven genome coverage because of amplification bias, background amplification of contaminating DNA, and formation of chimeras by linking of non-contiguous chromosomal regions. Here, we present a novel MDA method, termed droplet MDA, that minimizes amplification bias and amplification of contaminants by using picoliter-sized droplets for compartmentalized WGA reactions. Extracted DNA fragments from a lysed cell in MDA mixture are divided into 105 droplets (67 pL within minutes via flow through simple microfluidic channels. Compartmentalized genome fragments can be individually amplified in these droplets without the risk of encounter with reagent-borne or environmental contaminants. Following quality assessment of WGA products from single Escherichia coli cells, we showed that droplet MDA minimized unexpected amplification and improved the percentage of genome recovery from 59% to 89%. Our results demonstrate that microfluidic-generated droplets show potential as an efficient tool for effective amplification of low-input DNA for single-cell genomics and greatly reduce the cost and labor investment required for determination of nearly complete genome sequences of uncultured bacteria from environmental samples.

  19. Nestin- and doublecortin-positive cells reside in adult spinal cord meninges and participate in injury-induced parenchymal reaction.

    Science.gov (United States)

    Decimo, Ilaria; Bifari, Francesco; Rodriguez, Francisco Javier; Malpeli, Giorgio; Dolci, Sissi; Lavarini, Valentina; Pretto, Silvia; Vasquez, Sandra; Sciancalepore, Marina; Montalbano, Alberto; Berton, Valeria; Krampera, Mauro; Fumagalli, Guido

    2011-12-01

    Adult spinal cord has little regenerative potential, thus limiting patient recovery following injury. In this study, we describe a new population of cells resident in the adult rat spinal cord meninges that express the neural stem/precursor markers nestin and doublecortin. Furthermore, from dissociated meningeal tissue a neural stem cell population was cultured in vitro and subsequently shown to differentiate into functional neurons or mature oligodendrocytes. Proliferation rate and number of nestin- and doublecortin-positive cells increased in vivo in meninges following spinal cord injury. By using a lentivirus-labeling approach, we show that meningeal cells, including nestin- and doublecortin-positive cells, migrate in the spinal cord parenchyma and contribute to the glial scar formation. Our data emphasize the multiple roles of meninges in the reaction of the parenchyma to trauma and indicate for the first time that spinal cord meninges are potential niches harboring stem/precursor cells that can be activated by injury. Meninges may be considered as a new source of adult stem/precursor cells to be further tested for use in regenerative medicine applied to neurological disorders, including repair from spinal cord injury. Copyright © 2011 AlphaMed Press.

  20. Reactions of human dental pulp cells to capping agents in the presence or absence of bacterial exposure.

    Science.gov (United States)

    Cai, Shiwei; Zhang, Wenjian; Tribble, Gena; Chen, Wei

    2017-01-01

    An ideal pulp-capping agent needs to have good biocompatibility and promote reparative dentinogenesis. Although the effects of capping agents on healthy pulp are known, limited data regarding their effects on bacterial contaminated pulp are available. This study aimed to evaluate the reaction of contaminated pulps to various capping agents to assist clinicians in making informed decisions. Human dental pulp (HDP) cell cultures were developed from extracted human molars. The cells were exposed to a bacterial cocktail comprising Porphyromonas gingivalis, Prevotella intermedia, and Streptococcus gordonii before being cocultured with capping agents such as mineral trioxide aggregate (MTA) Portland cement (PC), and Dycal. HDP cell proliferation was assayed by MTS colorimetric cell proliferation assay, and its differentiation was evaluated by real-time PCR for detecting alkaline phosphatase, dentin sialophosphoprotein, and osteocalcin expressions. MTA and PC had no apparent effect, whereas Dycal inhibited HDP cell proliferation. PC stimulated HDP cell differentiation, particularly when they were exposed to bacteria. MTA and Dycal inhibited differentiation, regardless of bacterial infection. In conclusion, PC was the most favorable agent, followed by MTA, and Dycal was the least favorable agent for supporting the functions of bacterial compromised pulp cells.

  1. Dr.C. Guillermo Amaro Ivonet: modelo de profesional entregado al ejercicio de la pediatría en Santiago de Cuba

    Directory of Open Access Journals (Sweden)

    María Antonia Peña Sánchez

    2014-12-01

    Full Text Available En el presente trabajo se mencionan importantes aspectos de la vida y obra del Dr.C. Guillermo Amaro Ivonet; personalidad científica consagrada a la asistencia médica de la población infantil. La influencia de este ilustre pediatra en la formación de los médicos de niños de Santiago de Cuba ha sido encomiable. Su querida ciudad natal y su patria toda, se enorgullecen de haber podido contar con su prodigiosa sapiencia, caballerosidad, humanismo, ética profesional y ayuda médica para los más débiles, por más de 50 años

  2. Autologous hematopoietic stem cell transplantation in lymphoma patients is associated with a decrease in the double strand break repair capacity of peripheral blood lymphocytes.

    Science.gov (United States)

    Lacoste, Sandrine; Bhatia, Smita; Chen, Yanjun; Bhatia, Ravi; O'Connor, Timothy R

    2017-01-01

    Patients who undergo autologous hematopoietic stem cell transplantation (aHCT) for treatment of a relapsed or refractory lymphoma are at risk of developing therapy related- myelodysplasia/acute myeloid leukemia (t-MDS/AML). Part of the risk likely resides in inherent interindividual differences in their DNA repair capacity (DRC), which is thought to influence the effect chemotherapeutic treatments have on the patient's stem cells prior to aHCT. Measuring DRC involves identifying small differences in repair proficiency among individuals. Initially, we investigated the cell model in healthy individuals (primary lymphocytes and/or lymphoblastoid cell lines) that would be appropriate to measure genetically determined DRC using host-cell reactivation assays. We present evidence that interindividual differences in DRC double-strand break repair (by non-homologous end-joining [NHEJ] or single-strand annealing [SSA]) are better preserved in non-induced primary lymphocytes. In contrast, lymphocytes induced to proliferate are required to assay base excision (BER) or nucleotide excision repair (NER). We established that both NHEJ and SSA DRCs in lymphocytes of healthy individuals were inversely correlated with the age of the donor, indicating that DSB repair in lymphocytes is likely not a constant feature but rather something that decreases with age (~0.37% NHEJ DRC/year). To investigate the predictive value of pre-aHCT DRC on outcome in patients, we then applied the optimized assays to the analysis of primary lymphocytes from lymphoma patients and found that individuals who later developed t-MDS/AML (cases) were indistinguishable in their DRC from controls who never developed t-MDS/AML. However, when DRC was investigated shortly after aHCT in the same individuals (21.6 months later on average), aHCT patients (both cases and controls) showed a significant decrease in DSB repair measurements. The average decrease of 6.9% in NHEJ DRC observed among aHCT patients was much higher

  3. Autologous hematopoietic stem cell transplantation in lymphoma patients is associated with a decrease in the double strand break repair capacity of peripheral blood lymphocytes.

    Directory of Open Access Journals (Sweden)

    Sandrine Lacoste

    Full Text Available Patients who undergo autologous hematopoietic stem cell transplantation (aHCT for treatment of a relapsed or refractory lymphoma are at risk of developing therapy related- myelodysplasia/acute myeloid leukemia (t-MDS/AML. Part of the risk likely resides in inherent interindividual differences in their DNA repair capacity (DRC, which is thought to influence the effect chemotherapeutic treatments have on the patient's stem cells prior to aHCT. Measuring DRC involves identifying small differences in repair proficiency among individuals. Initially, we investigated the cell model in healthy individuals (primary lymphocytes and/or lymphoblastoid cell lines that would be appropriate to measure genetically determined DRC using host-cell reactivation assays. We present evidence that interindividual differences in DRC double-strand break repair (by non-homologous end-joining [NHEJ] or single-strand annealing [SSA] are better preserved in non-induced primary lymphocytes. In contrast, lymphocytes induced to proliferate are required to assay base excision (BER or nucleotide excision repair (NER. We established that both NHEJ and SSA DRCs in lymphocytes of healthy individuals were inversely correlated with the age of the donor, indicating that DSB repair in lymphocytes is likely not a constant feature but rather something that decreases with age (~0.37% NHEJ DRC/year. To investigate the predictive value of pre-aHCT DRC on outcome in patients, we then applied the optimized assays to the analysis of primary lymphocytes from lymphoma patients and found that individuals who later developed t-MDS/AML (cases were indistinguishable in their DRC from controls who never developed t-MDS/AML. However, when DRC was investigated shortly after aHCT in the same individuals (21.6 months later on average, aHCT patients (both cases and controls showed a significant decrease in DSB repair measurements. The average decrease of 6.9% in NHEJ DRC observed among aHCT patients was

  4. Accounting for recent trends in the prevalence of diarrhoea in the Democratic Republic of Congo (DRC): results from consecutive cross-sectional surveys.

    Science.gov (United States)

    Emina, Jacques B O; Kandala, Ngianga-Bakwin

    2012-01-01

    To analyse trends in diarrhoea prevalence by maternal education, access to clean water and improved sanitation, household wealth index; to identify the sources of variation and assess contribution of changes in socioeconomic characteristics in the Democratic Republic of Congo (DRC). Consecutive cross-sectional surveys. DRC. The databases contain information on 9748 children from the 2001 Multiple Indicators Cluster Survey and 7987 children from the 2007 Demographic and Health Survey. N/A. Whether the child had diarrhoea 14 days preceding the survey. The overall prevalence of diarrhoea decreased by 26 percent (from 22.1% in 2001 to 16.4% in 2007). Findings from the three complementary statistical methods are consistent and confirm a significant decrease in diarrhoea regardless of socioeconomic characteristics. Changes in behaviour and/or in public health policy seem to be the likely main source of the change. There were no significant changes in diarrhoea prevalence associated with variation of the population structure. It is worth mentioning that the decrease in diarrhoea prevalence is in contrast to the generalised poor living conditions of the population. Therefore, it is difficult to ascertain whether the decline in diarrhoea prevalence was due to real improvement in public-health policy or to data quality issues. The decline of diarrhoea prevalence in our study need to be further investigated by conducting district-based or provincial-based studies to validate findings from household surveys such as Demographic and Health Surveys and Multiple Indicators Cluster Survey taking into account the current context of the country: ongoing conflict, poor socioeconomic and poor health infrastructure. However, improvement in living conditions such as access to clean water and improved sanitation will contribute to accelerate the reduction of diarrhoea prevalence as well as reduction of child mortality.

  5. Abducted children and youth in Lord's Resistance Army in Northeastern Democratic Republic of the Congo (DRC): mechanisms of indoctrination and control.

    Science.gov (United States)

    Kelly, Jocelyn Td; Branham, Lindsay; Decker, Michele R

    2016-01-01

    Globally, an estimated 300,000 children under the age of 18 participate in combat situations; those in armed groups in particular suffer prolonged exposure to psychological and physical abuse. The Lord's Resistance Army (LRA) is a rebel movement known for its widespread conscription of children; yet little is known about this process once the group moved beyond northern Uganda. In this paper, we describe the processes related to abduction and indoctrination of youth by the LRA in northeastern Democratic Republic of the Congo ( DRC). In-depth interviews were conducted with formerly abducted children, their family members, community leaders, and service providers (total n = 34) in four communities in LRA-affected areas of northeastern DRC. Inductive coding of transcripts was undertaken to identify salient themes. Informants articulated a range of practices by the LRA to exert high levels of control over new recruits, including strict social isolation from recent abductees; control of communication; promoting new identity formation; and compelling children to act out strictly defined gendered roles. Witchcraft and secrecy are used to intimidate recruits and to magnify perception of the group's power. These methods promote de-identification with one's civilian and family life; and eventually the assimilation of a new language and identity. Indoctrination of newly abducted children into the LRA occurs via a complex system of control. This study provides one of the first detailed explorations of social and psychological mechanisms through which this is achieved, and focuses particularly on the gendered differences in the indoctrination process. Results support past findings that the LRA is a strategic and well-organized organization in its approach to enlisting child soldiers. Understanding some of the ways in which the LRA controls its recruits and the psychological impact of indoctrination enables reintegration programs to more effectively address these issues

  6. Determination of redox reaction rates and orders by in situ liquid cell electron microscopy of Pd and Au solution growth.

    Science.gov (United States)

    Sutter, Eli A; Sutter, Peter W

    2014-12-03

    In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important, as they provide direct insight into processes in liquids, such as solution growth of nanoparticles, among others. In liquid cell TEM/STEM redox reaction experiments, the hydrated electrons e(-)aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e(-)aq generated by the electron beam during in situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pd deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e(-)aq]. By comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e(-)aq] but also the rate of reduction of a metal-ion complex to zerovalent metal atoms in solution.

  7. Plasma Deposited Thin Iron Oxide Films as Electrocatalyst for Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Lukasz JOZWIAK

    2017-02-01

    Full Text Available The possibility of using plasma deposited thin films of iron oxides as electrocatalyst for oxygen reduction reaction (ORR in proton exchange membrane fuel cells (PEMFC was examined. Results of energy-dispersive X-ray spectroscopy (EDX and X-ray photoelectron spectroscopy (XPS analysis indicated that the plasma deposit consisted mainly of FeOX structures with the X parameter close to 1.5. For as deposited material iron atoms are almost exclusively in the Fe3+ oxidation state without annealing in oxygen containing atmosphere. However, the annealing procedure can be used to remove the remains of carbon deposit from surface. The single cell test (SCT was performed to determine the suitability of the produced material for ORR. Preliminary results showed that power density of 0.23 mW/cm2 could be reached in the tested cell.DOI: http://dx.doi.org/10.5755/j01.ms.23.1.14406

  8. Changes in circulating inflammatory markers following febrile non-haemolytic transfusion reactions to leucoreduced red cells

    DEFF Research Database (Denmark)

    Larsen, R; Sandhu, N; Heegaard, N H H

    2018-01-01

    It would be desirable to be able to distinguish fever as a result of febrile non-haemolytic transfusion reactions (FNHTR) from other febrile conditions. To further characterize the inflammatory feature of FNHTR, we measured a large panel of inflammatory markers in pre- and posttransfusion plasma...

  9. Sulfur Poisoning of the Water Gas Shift Reaction on Anode Supported Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Hagen, Anke

    2013-01-01

    resistance increased both in the high and low frequency region, which indicates a strong poisoning of the water gas shift reaction and thus a lack of hydrogen fuel in addition to the poisoning of the electrochemical hydrogen oxidation. All poisoning effects are reversible under the applied operating...

  10. Skin reactions and quality of life after x-ray therapy of Basal cell carcinoma

    DEFF Research Database (Denmark)

    Skiveren, Jette; Mikkelsen, Maria Rudkjaer; Daugbjerg, Helle

    2012-01-01

    controls (P = 0.819). Three months after X-ray therapy eight patients had no skin reactions, 11 had slight atrophy, pigmentation change, and/or some hair loss, four had patch atrophy, moderate telangiectasia, and/or total hair loss. Conclusions. BCC has a negative effect on patients' quality of life...

  11. Multi-element Analysis of variable sample matrices using collision/reaction cell inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Zahran, N.F.; Helal, A.I.; Amr, M.A.; Amr, M.A.; Al-saad, K.A.

    2008-01-01

    An ICP-MS with an octopole reaction/collision cell is used for the multielement determination of trace elements in water, plants, and soil samples. The use of a reaction or collision gas reduces serious spectral interferences from matrix elements such as Ar Cl or Ar Na. The background equivalent concentration (BEC) is reduced one order of magnitude at helium flow rate of 1 mL/min. Certified reference material namely , NIST Water-1643d, Tomato leaves 1573a, and Montana soil 2711 are used. The trace elements Mn, Fe, Co, Ni, Cu, Zn, As, Mo, Cd and Pb are determined in the different matrices with a accuracy better than 8% to the certified values

  12. A rare case of sarcoid-like reaction of lymph nodes associated with squamous cell carcinoma of alveolar mucosa

    Directory of Open Access Journals (Sweden)

    Nag Shweta

    2009-01-01

    Full Text Available Non-necrotizing granulomas are occasionally seen in patients with certain malignant disorders and are termed as "sarcoid-like reaction," which have many similarities with sarcoidosis. Sarcoidosis is a multisystem granulomatous disease of unknown etiology characterized by organ involvement and interference of organ function by granuloma or fibrosis. Sarcoidosis is occasionally found in a variety of malignant diseases with an overall incidence of 4.4% in carcinoma patients. We present here a rare case of moderately differentiated squamous cell carcinoma of alveolar mucosa with regard to mandible associated with sarcoid-like reaction of cervical lymph nodes in a female patient in the absence of clinical evidence of systemic sarcoidosis. The relevant literature including pathogenesis is also discussed.

  13. Electrochemical characterization of Pt-Ru-Pd catalysts for methanol oxidation reaction in direct methanol fuel cells.

    Science.gov (United States)

    Choi, M; Han, C; Kim, I T; An, J C; Lee, J J; Lee, H K; Shim, J

    2011-01-01

    PtRuPd nanoparticles on carbon black were prepared and characterized as electrocatalysts for methanol oxidation reaction in direct methanol fuel cells. Nano-sized Pd (2-4 nm) particles were deposited on Pt/C and PtRu/C (commercial products) by a simple chemical reduction process. The structural and physical information of the PtRuPd/C were confirmed by TEM and XRD, and their electrocatalytic activities were measured by cyclic voltammetry and linear sweep voltammetry. The catalysts containing Pd showed higher electrocatalytic activity for methanol oxidation reaction than the other catalysts. This might be attributed to an increase in the electrochemical surface area of Pt, which is caused by the addition of Pd; this results in increased catalyst utilization.

  14. Reflection-mode x-ray powder diffraction cell for in situ studies of electrochemical reactions

    International Nuclear Information System (INIS)

    Roberts, G.A.; Stewart, K.D.

    2004-01-01

    The design and operation of an electrochemical cell for reflection-mode powder x-ray diffraction experiments are discussed. The cell is designed for the study of electrodes that are used in rechargeable lithium batteries. It is designed for assembly in a glove box so that air-sensitive materials, such as lithium foil electrodes and carbonate-based electrolytes with lithium salts, can be used. The cell uses a beryllium window for x-ray transmission and electrical contact. A simple mechanism for compressing the electrodes is included in the design. Sample results for the cell are shown with a Cu Kα source and a position-sensitive detector

  15. An Immunofluorescence-assisted Microfluidic Single Cell Quantitative Reverse Transcription Polymerase Chain Reaction Analysis of Tumour Cells Separated from Blood

    Directory of Open Access Journals (Sweden)

    Kazunori Hoshino

    2015-11-01

    matched the results from a few thousand cells. Some markers (e.g., ER, HER2 that are commonly used for cancer identification showed relatively large deviations in expres‐ sion levels. However, others (e.g., GRB7 showed devia‐ tions that are small enough to supplement single cell disease profiling.

  16. Analysis of transport phenomena and electrochemical reactions in a micro PEM fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Sadiq Al-Baghdadi, Maher A.R. [Fuel Cell Research Center, International Energy and Environment Foundation, Najaf, P.O.Box 39 (Iraq)

    2013-07-01

    Micro-fuel cells are considered as promising electrochemical power sources in portable electronic devices. The presence of microelectromechanical system (MEMS) technology makes it possible to manufacture the miniaturized fuel cell systems. The majority of research on micro-scale fuel cells is aimed at micro-power applications. Performance of micro-fuel cells are closely related to many factors, such as designs and operating conditions. CFD modeling and simulation for heat and mass transport in micro PEM fuel cells are being used extensively in researches and industrial applications to gain better understanding of the fundamental processes and to optimize the micro fuel cell designs before building a prototype for engineering application. In this research, full three-dimensional, non-isothermal computational fluid dynamics model of a micro proton exchange membrane (PEM) fuel cell has been developed. This comprehensive model accounts for the major transport phenomena such as convective and diffusive heat and mass transfer, electrode kinetics, transport and phase-change mechanism of water, and potential fields in a micro PEM fuel cell. The model explains many interacting, complex electrochemical, and transport phenomena that cannot be studied experimentally. Three-dimensional results of the species profiles, temperature distribution, potential distribution, and local current density distribution are presented and analysed, with the focus on the physical insight and fundamental understanding.

  17. Reaction and catalyst engineering to exploit kinetically controlled whole-cell multistep biocatalysis for terminal FAME oxyfunctionalization.

    Science.gov (United States)

    Schrewe, Manfred; Julsing, Mattijs K; Lange, Kerstin; Czarnotta, Eik; Schmid, Andreas; Bühler, Bruno

    2014-09-01

    The oxyfunctionalization of unactivated C−H bonds can selectively and efficiently be catalyzed by oxygenase-containing whole-cell biocatalysts. Recombinant Escherichia coli W3110 containing the alkane monooxygenase AlkBGT and the outer membrane protein AlkL from Pseudomonas putida GPo1 have been shown to efficiently catalyze the terminal oxyfunctionalization of renewable fatty acid methyl esters yielding bifunctional products of interest for polymer synthesis. In this study, AlkBGTL-containing E. coli W3110 is shown to catalyze the multistep conversion of dodecanoic acid methyl ester (DAME) via terminal alcohol and aldehyde to the acid, exhibiting Michaelis-Menten-type kinetics for each reaction step. In two-liquid phase biotransformations, the product formation pattern was found to be controlled by DAME availability. Supplying DAME as bulk organic phase led to accumulation of the terminal alcohol as the predominant product. Limiting DAME availability via application of bis(2-ethylhexyl)phthalate (BEHP) as organic carrier solvent enabled almost exclusive acid accumulation. Furthermore, utilization of BEHP enhanced catalyst stability by reducing toxic effects of substrate and products. A further shift towards the overoxidized products was achieved by co-expression of the gene encoding the alcohol dehydrogenase AlkJ, which was shown to catalyze efficient and irreversible alcohol to aldehyde oxidation in vivo. With DAME as organic phase, the aldehyde accumulated as main product using resting cells containing AlkBGT, AlkL, as well as AlkJ. This study highlights the versatility of whole-cell biocatalysis for synthesis of industrially relevant bifunctional building blocks and demonstrates how integrated reaction and catalyst engineering can be implemented to control product formation patterns in biocatalytic multistep reactions. © 2014 Wiley Periodicals, Inc.

  18. Analysis of a Mathematical Model of Lithium-Sulfur Cells Part III: Electrochemical Reaction Kinetics, Transport Properties and Charging

    International Nuclear Information System (INIS)

    Ghaznavi, Mahmoudreza; Chen, P.

    2014-01-01

    Highlights: • The discharge behavior of Li-S cells in wide range of exchange current densities of electrochemical reactions is studied. • Among all reduction reactions, 1/2 S 8(l) +e − ⇌1/2 S 8 2− and 1/2 S 2 2− +e − ⇌2S 2− play the most important role in capacity performance. • Low diffusion increases the precipitation of polysulfides in separator which may block the anode surface. • Large solubility of Li 2 S is needed for the model to be able to simulate the charging process. - Abstract: Sensitivity analysis of a mathematical model of a lithium-sulfur (Li-S) battery was performed by investigating the response of the model to variation of the exchange current densities, diffusion coefficients, and cathode thickness over a wide range; the results of the analysis were used to explain the some aspects of the behavior of the system which may be seen in experiments. In particular, among all the exchange current densities, the exchange current density of the elemental sulfur reduction has the most significant effect on the discharge capacity of the cell. The variation of the diffusion coefficients was also analyzed, providing information on the non-uniformity of precipitants in the cell after discharge. An optimum cathode thickness was presented to gain the highest capacity of the cell. Finally, the simulation of charging was studied, showing that the model needs a large solubility product of di-lithium sulfide to be able to simulate the charge process of a cell

  19. Cell phone ringtone, but not landline phone ringtone, affects complex reaction time

    OpenAIRE

    Radosław Zajdel; Justyna Zajdel; Janusz Śmigielski; Dariusz Nowak

    2013-01-01

    Introduction: Legislation systems of most countries prohibited using the handheld mobile phone while driving due to the fact that it disturbs concentration and causes hand involvement. Every phone owner is accustomed to the ringtone of his phone and almost involuntarily endeavors to pick it up or check who calls. This engages one’s psychomotor skills, which in our opinion contributes to the attenuation of reaction time needed for performing other crucial functions. Objectives: The aim of the ...

  20. Multiple reaction monitoring targeted LC-MS analysis of potential cell death marker proteins for increased bioprocess control.

    Science.gov (United States)

    Albrecht, Simone; Kaisermayer, Christian; Reinhart, David; Ambrose, Monica; Kunert, Renate; Lindeberg, Anna; Bones, Jonathan

    2018-05-01

    The monitoring of protein biomarkers for the early prediction of cell stress and death is a valuable tool for process characterization and efficient biomanufacturing control. A representative set of six proteins, namely GPDH, PRDX1, LGALS1, CFL1, TAGLN2 and MDH, which were identified in a previous CHO-K1 cell death model using discovery LC-MS E was translated into a targeted liquid chromatography multiple reaction monitoring mass spectrometry (LC-MRM-MS) platform and verified. The universality of the markers was confirmed in a cell growth model for which three Chinese hamster ovary host cell lines (CHO-K1, CHO-S, CHO-DG44) were grown in batch culture in two different types of basal media. LC-MRM-MS was also applied to spent media (n = 39) from four perfusion biomanufacturing series. Stable isotope-labelled peptide analogues and a stable isotope-labelled monoclonal antibody were used for improved protein quantitation and simultaneous monitoring of the workflow reproducibility. Significant increases in protein concentrations were observed for all viability marker proteins upon increased dead cell numbers and allowed for discrimination of spent media with dead cell densities below and above 1 × 10 6  dead cells/mL which highlights the potential of the selected viability marker proteins in bioprocess control. Graphical abstract Overview of the LC-MRM-MS workflow for the determination of proteomic markers in conditioned media from the bioreactor that correlate with CHO cell death.

  1. Reaction of oxygen with the respiratory chain in cells and tissues.

    Science.gov (United States)

    Chance, B

    1965-09-01

    This paper considers the way in which the oxygen reaction described by Dr. Nicholls and the ADP control reactions described by Dr. Racker could cooperate to establish a purposeful metabolic control phenomenon in vivo. This has required an examination of the kinetic properties of the respiratory chain with particular reference to methods for determinations of oxygen affinity (K(m)). The constant parameter for tissue respiration is k(1), the velocity constant for the reaction of oxygen with cytochrome oxidase. Not only is this quantity a constant for a particular tissue or mitochondria; it appears to vary little over a wide range of biological material, and for practical purposes a value of 5 x 10(7) at 25 degrees close to our original value (20) is found to apply with adequate accuracy for calculation of K(m) for mammalia. The quantity which will depend upon the tissue and its metabolic state is the value of K(m) itself, and K(m) may be as large as 0.5 microM and may fall to 0.05 microM or less in resting, controlled, or inhibited states. The control characteristic for ADP may depend upon the electron flux due to the cytochrome chain (40); less ADP is required to activate the slower electron transport at lower temperatures than at higher temperatures. The affinity constants for ADP control appear to be less dependent upon substrate supplied to the system. The balance of ADP and oxygen control in vivo is amply demonstrated experimentally and is dependent on the oxygen concentration as follows. In the presence of excess oxygen, control may be due to the ADP or phosphate (or substrate), and the kinetics of oxygen utilization will be independent of the oxygen concentration. As the oxygen concentration is diminished, hemoglobin becomes disoxygenated, deep gradients of oxygen concentration develop in the tissue, and eventually cytochrome oxidase becomes partially and then completely reduced. DPN at this point will become reduced and the electron flow diminished. The rate

  2. Monitoring dynamic reactions of red blood cells to UHF electromagnetic waves radiation using a novel micro-imaging technology.

    Science.gov (United States)

    Ruan, Ping; Yong, Junguang; Shen, Hongtao; Zheng, Xianrong

    2012-12-01

    Multiple state-of-the-art techniques, such as multi-dimensional micro-imaging, fast multi-channel micro-spetrophotometry, and dynamic micro-imaging analysis, were used to dynamically investigate various effects of cell under the 900 MHz electromagnetic radiation. Cell changes in shape, size, and parameters of Hb absorption spectrum under different power density electromagnetic waves radiation were presented in this article. Experimental results indicated that the isolated human red blood cells (RBCs) do not have obviously real-time responses to the ultra-low density (15 μW/cm(2), 31 μW/cm(2)) electromagnetic wave radiation when the radiation time is not more than 30 min; however, the cells do have significant reactions in shape, size, and the like, to the electromagnetic waves radiation with power densities of 1 mW/cm(2) and 5 mW/cm(2). The data also reveal the possible influences and statistical relationships among living human cell functions, radiation amount, and exposure time with high-frequency electromagnetic waves. The results of this study may be significant on protection of human being and other living organisms against possible radiation affections of the high-frequency electromagnetic waves.

  3. Increased expression of TACI on NOD B cells results in germinal centre reaction anomalies, enhanced plasma cell differentiation and immunoglobulin production.

    Science.gov (United States)

    Banday, Viqar S; Thyagarajan, Radha; Sundström, Mia; Lejon, Kristina

    2016-11-01

    B cells have an important pathogenic role in the development of type 1 diabetes in the non-obese diabetic (NOD) mouse. We have previously reported that NOD mice display an increased percentage of TACI high -expressing B cells compared with C57BL/6 mice and this trait is linked to chromosomes 1 and 8. In this paper the genetic association of the transmembrane activator, calcium modulator and cyclophilin ligand interactor (TACI) trait was confirmed using double congenic NOD.B6C1/Idd22 mice. TACI ligation by a proliferation-inducing ligand (APRIL) has been shown to influence plasma cell differentiation, immunoglobulin production and isotype switch. Hence, the functional consequence of the up-regulation of TACI on NOD B cells was analysed both in vitro and in vivo. NOD B cells stimulated with APRIL showed an enhanced plasma cell differentiation and class switch to IgG and IgA compared with B cells from C57BL/6 mice. Moreover, flow cytometry analyses revealed that germinal centre B cells in NOD failed to down-regulate TACI. Availability of the TACI ligand B-cell activating factor (BAFF) has been shown to be a limiting factor in the germinal centre reaction. In line with this, upon immunization with 4-hydroxy-3-nitrophenylacetyl hapten-conjugated hen egg lysozyme, NOD mice produced higher titres of low-affinity antibodies compared with C57BL/6 mice. This observation was supported by the detection of increased levels of BAFF in NOD germinal centres after immunization compared with C57BL/6 by immunofluorescence. Our results support the hypothesis that increased TACI expression on NOD B cells contributes to the pathogenesis of type 1 diabetes in the NOD mouse. © 2016 John Wiley & Sons Ltd.

  4. Reactional Plasmacytosis In Plasma Cell Orificial mucositis In A Patient Of Pulmonary Tuberculosis

    Directory of Open Access Journals (Sweden)

    Bose Sumit Kumar

    1997-01-01

    Full Text Available Skin biopsy of a 50 year old Moroccan male patient with labial and oro-pharyngeal plasmocytosis showed hyperplastic, with papillomatous eroded epithelium. Dense infiltrates of plasma cells were seen in the dermis, with perivascular prominence. Hypopharynx, epiglottis, adenoids, and tonsils showed the same type of infiltration. Immunofluorescence (IF and peroxidase antiperoxidase (PAP techniques demonstrated the presence of mostly and infiltrate of plasma cells showing IgA (30 â€" 40%, IgM (20-30%, IgG(10-20% after staining with polyclonal antibodies along with T4 & T8 Iymphocytes with monoclonal staining. Electron microscopy showed absence of atypical plasma cells with abundant endoplasmic reticulum. Patient’s symptoms of stomtitis, dysphonia and pharyngitis were temporarily relieved by systemic corticosteroids of plasma cells suggesting a reactive type of benign plasmocytosis.

  5. Enhancing the methanol tolerance of platinum nanoparticles for the cathode reaction of direct methanol fuel cells through a geometric design.

    Science.gov (United States)

    Feng, Yan; Ye, Feng; Liu, Hui; Yang, Jun

    2015-11-18

    Mastery over the structure of nanoparticles might be an effective way to enhance their performance for a given application. Herein we demonstrate the design of cage-bell nanostructures to enhance the methanol tolerance of platinum (Pt) nanoparticles while remaining their catalytic activity for oxygen reduction reaction. This strategy starts with the synthesis of core-shell-shell nanoparticles with Pt and silver (Ag) residing respectively in the core and inner shell regions, which are then agitated with saturated sodium chloride (NaCl) solution to eliminate the Ag component from the inner shell region, leading to the formation of bimetallic nanoparticles with a cage-bell structure, defined as a movable Pt core enclosed by a metal shell with nano-channels, which exhibit superior methanol-tolerant property in catalyzing oxygen reduction reaction due to the different diffusion behaviour of methanol and oxygen in the porous metal shell of cage-bell structured nanoparticles. In particular, the use of remarkably inexpensive chemical agent (NaCl) to promote the formation of cage-bell structured particles containing a wide spectrum of metal shells highlights its engineering merit to produce highly selective electrocatalysts on a large scale for the cathode reaction of direct methanol fuel cells.

  6. Cellular reactions of osteoblast-like cells to a novel nanocomposite membrane for guided bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Meng Yao [State Key Laboratory of Oral Diseases, West China Stomatology Hospital, Sichuan University, Chengdu 610041 (China); Department of Orthodontics, West China Stomatology Hospital, Sichuan University, Chengdu 610041 (China); Liu Man [State Key Laboratory of Oral Diseases, West China Stomatology Hospital, Sichuan University, Chengdu 610041 (China); Stomatology Health Care Center, Shenzhen Maternity and Child Healthcare Hospital, Shenzhen 518048 (China); Wang Shaoan [State Key Laboratory of Oral Diseases, West China Stomatology Hospital, Sichuan University, Chengdu 610041 (China); Mo Anchun [State Key Laboratory of Oral Diseases, West China Stomatology Hospital, Sichuan University, Chengdu 610041 (China)], E-mail: moanchun@163.com; Huang, Cui [State Key Laboratory of Oral Diseases, West China Stomatology Hospital, Sichuan University, Chengdu 610041 (China); Zuo Yi; Li Jidong [Research Center for Nano-biomaterials, Sichuan University, Chengdu 610041 (China)

    2008-11-15

    This study investigated the bioactivity and biocompatibility of hydroxyapatite nanoparticles (n-HA)/Polyamide-66 (PA66) nanocomposite membrane and expanded-polytetrafluoroethylene (e-PTFE) membrane (as control) to MG63 osteoblast-like cells. The attachment and proliferation of the cells on the porous surface of nHA/PA66 membrane and the surface of e-PTFE membrane were evaluated by scanning electron microscope (SEM) observation and the MTT assay. The bioactivity of the cells on the surface of the two membranes was evaluated by testing cell viability and alkaline phosphatase (ALP) activities. The results suggested that the bioresponse of MG63 osteoblast-like cells on the porous surface of nHA/PA66 membrane was better than the bioresponse on the opposite surface of e-PTFE membrane. Because of a better cell attachment manner, there is a potential utilization of the guided bone regeneration (GBR) membrane to substitute nHA/PA66 membrane for e-PTFE membra0008.

  7. Cellular reactions of osteoblast-like cells to a novel nanocomposite membrane for guided bone regeneration

    International Nuclear Information System (INIS)

    Meng Yao; Liu Man; Wang Shaoan; Mo Anchun; Huang, Cui; Zuo Yi; Li Jidong

    2008-01-01

    This study investigated the bioactivity and biocompatibility of hydroxyapatite nanoparticles (n-HA)/Polyamide-66 (PA66) nanocomposite membrane and expanded-polytetrafluoroethylene (e-PTFE) membrane (as control) to MG63 osteoblast-like cells. The attachment and proliferation of the cells on the porous surface of nHA/PA66 membrane and the surface of e-PTFE membrane were evaluated by scanning electron microscope (SEM) observation and the MTT assay. The bioactivity of the cells on the surface of the two membranes was evaluated by testing cell viability and alkaline phosphatase (ALP) activities. The results suggested that the bioresponse of MG63 osteoblast-like cells on the porous surface of nHA/PA66 membrane was better than the bioresponse on the opposite surface of e-PTFE membrane. Because of a better cell attachment manner, there is a potential utilization of the guided bone regeneration (GBR) membrane to substitute nHA/PA66 membrane for e-PTFE membrane

  8. Effect of Green Tea Extract on T cell Mediated Hypersensitivity Reaction in BALB/c Mice Exposed to Gamma Irradiation

    International Nuclear Information System (INIS)

    Hashim, A.M.; Ismail Al-kadey, M.M.I.; Shabon, M.H.; Hussien, S.M.

    2010-01-01

    Gamma radiation is widely used in the treatment of malignant neoplasms. However, it deprives the host immune function which may retard tumor rejection by the immune response. The main purpose of the present study is to test the ability of green tea dry extract to restore the T cell hypersensitivity reaction in gamma irradiated BALB/c mice. It aims also to elucidate the possible mechanism of action of ionizing radiation and green tea dry extract in the immune function. Four groups of BALB/c mice, each of ten, have been used in each experiment. The first group served as a control, the second group received green tea dry extract and the third group was exposed to 2 Gy gamma irradiation, while the fourth group received green tea dry extract before and after gamma irradiation. The following parameters were determined, the contact sensitivity reaction by the mouse ear swelling response, local dendritic cell migration, local lymph node weight, lymphocyte proliferation, spleen and thymus weight with their lymphocyte count. The effect of gamma irradiation and green tea dry extract on the elicitation phase of contact sensitivity was also determined. Data from the present study showed that gamma irradiation caused a significant decrease of the mouse ear swelling response and retarded dendritic cell migration. They also showed a significant decline in the lymphocytes proliferation in lymph node draining the contact sensitizer application. Total body exposure to 2 Gy gamma irradiation induced marked decline of thymus weight and thymocyte count, while it reduced spleen weight and spleenocyte count to a lesser extent. Exposure to gamma irradiation enhanced the elicitation phase of contact sensitivity. Administration of green tea dry extract partially preserved the contact sensitivity response to oxazolone in gamma irradiated BALB/c mice. It markedly minimized the enhancement of the elicitation phase of ear swelling. In conclusion, the present study heralds a beneficial role of

  9. Montreal Cognitive Assessment (MoCA no rastreio de comprometimento cognitivo leve (CCL em pacientes com doença renal crônica (DRC pré-dialítica

    Directory of Open Access Journals (Sweden)

    Marilise de Andrade Paraizo

    2016-03-01

    Full Text Available Resumo Introdução: Indivíduos com doença renal crônica (DRC têm grande risco de desenvolver comprometimento cognitivo (CC, inicialmente leve (CCL, passível de identificação, mas ainda subdiagnosticado e subtratado. O Montreal Cognitive Assessment (MoCA vem sendo indicado para rastreio de CCL na DRC. Objetivo: Avaliar o CCL em indivíduos com DRC pré-dialítica. Métodos: O estudo foi realizado em 72 indivíduos, não idosos, com DRC nos estágios pré-dialíticos. A avaliação neuropsicológica incluiu: o teste de cognição global MoCA; o teste do relógio (TDR; o Digit Span ordem direta (DOD e inversa (DOI; o teste de fluência verbal (FV, fonêmica (FAS e semântica (animais; o punho-borda-mão (PBM; e de memória 10 figuras. Resultados: A média de idade dos participantes foi de 56,74 ± 7,63 anos, com predominância de homens (55,6%, com escolaridade ≥ 4 anos (84,3%, a maioria com DRC 1, 2 e 3a e 3b (67,6%, hipertensa (93,1% e diabética (52,1%. O CC (MoCA ≤ 24 foi observado em 73,6% dos usuários. Não encontramos associação das variáveis demográficas e clínicas com CC, mas tendência de associação com a idade (p = 0,07, com a escolaridade (p = 0,06 e com o DM (0,06. Os testes de função executiva, TDR, DOI e PBM, isoladamente, apresentaram boa sensibilidade e valor preditivo negativo comparados ao MoCA para a identificação de CC e, em conjunto, foram capazes de predizer o resultado do MoCA. Conclusão: O CCL é frequente em usuários não idosos com DRC pré-dialítica. O TDR, DOI e PBM associados são equivalentes ao MoCA na identificação do CC nessa população, sugerindo comprometimento de funções executivas.

  10. Cross-flow electrochemical reactor cells, cross-flow reactors, and use of cross-flow reactors for oxidation reactions

    Science.gov (United States)

    Balachandran, Uthamalingam; Poeppel, Roger B.; Kleefisch, Mark S.; Kobylinski, Thaddeus P.; Udovich, Carl A.

    1994-01-01

    This invention discloses cross-flow electrochemical reactor cells containing oxygen permeable materials which have both electron conductivity and oxygen ion conductivity, cross-flow reactors, and electrochemical processes using cross-flow reactor cells having oxygen permeable monolithic cores to control and facilitate transport of oxygen from an oxygen-containing gas stream to oxidation reactions of organic compounds in another gas stream. These cross-flow electrochemical reactors comprise a hollow ceramic blade positioned across a gas stream flow or a stack of crossed hollow ceramic blades containing a channel or channels for flow of gas streams. Each channel has at least one channel wall disposed between a channel and a portion of an outer surface of the ceramic blade, or a common wall with adjacent blades in a stack comprising a gas-impervious mixed metal oxide material of a perovskite structure having electron conductivity and oxygen ion conductivity. The invention includes reactors comprising first and second zones seprated by gas-impervious mixed metal oxide material material having electron conductivity and oxygen ion conductivity. Prefered gas-impervious materials comprise at least one mixed metal oxide having a perovskite structure or perovskite-like structure. The invention includes, also, oxidation processes controlled by using these electrochemical reactors, and these reactions do not require an external source of electrical potential or any external electric circuit for oxidation to proceed.

  11. DNA damage and radical reactions: Mechanistic aspects, formation in cells and repair studies

    International Nuclear Information System (INIS)

    Cadet, J.; Ravanat, J.L.; Carell, T.; Cellai, L.; Chatgilialoglu, Ch.; Gimisis, Th.; Miranda, M.; O'Neill, P.; Robert, M.

    2008-01-01

    Several examples of oxidative and reductive reactions of DNA components that lead to single and tandem modifications are discussed in this review. These include nucleophilic addition reactions of the one-electron oxidation-mediated guanine radical cation and the one-electron reduced intermediate of 8-bromo-purine 2'-de-oxy-ribo-nucleosides that give rise to either an oxidizing guanine radical or related 5',8-cyclo-purine nucleosides. In addition, mechanistic insights into the reductive pathways involved in the photolyase induced reversal of cyclo-buta-cli-pyrimidine and pyrimidine (6-4) pyrimidone photoproducts are provided. Evidence for the occurrence and validation in cellular DNA of (OH) · radical degradation pathways of guanine that have been established in model systems has been gained from the accurate measurement of degradation products. Relevant information on biochemical aspects of the repair of single and clustered oxidatively generated damage to DNA has been gained from detailed investigations that rely on the synthesis of suitable modified probes. Thus the preparation of stable carbocyclic derivatives of purine nucleoside containing defined sequence oligonucleotides has allowed detailed crystallographic studies of the recognition step of the base damage by enzymes implicated in the base excision repair (BER) pathway. Detailed insights are provided on the BER processing of non-double strand break bi-stranded clustered damage that may consist of base lesions, a single strand break or abasic sites and represent one of the main deleterious classes of radiation-induced DNA damage. (authors)

  12. Dose rate effect models for biological reaction to ionizing radiation in human cell lines

    International Nuclear Information System (INIS)

    Magae, Junji; Ogata, Hiromitsu

    2008-01-01

    Full text: Because of biological responses to ionizing radiation are dependent on irradiation time or dose rate as well as dose, simultaneous inclusion of dose and dose rate is required to evaluate the risk of long term irradiation at low dose rates. We previously published a novel statistical model for dose rate effect, modified exponential (MOE) model, which predicts irradiation time-dependent biological response to low dose rate ionizing radiation, by analyzing micronucleus formation and growth inhibition in a human osteosarcoma cell line, exposed to wide range of doses and dose rates of gamma-rays. MOE model demonstrates that logarithm of median effective dose exponentially increases in low dose rates, and thus suggests that the risk approaches to zero at infinitely low dose rate. In this paper, we extend the analysis in various kinds of human cell lines exposed to ionizing radiation for more than a year. We measured micronucleus formation and [ 3 H]thymidine uptake in human cell lines including an osteosarcoma, a DNA-dependent protein kinase-deficient glioma, a SV40-transformed fibroblast derived from an ataxia telangiectasia patient, a normal fibroblast, and leukemia cell lines. Cells were exposed to gamma-rays in irradiation room bearing 50,000 Ci of cobalt-60. After the irradiation, they were cultured for 24 h in the presence of cytochalasin B to block cytokinesis, and cytoplasm and nucleus were stained with DAPI and prospidium iodide. The number of binuclear cells bearing a micronucleus was counted under a fluorescence microscope. For proliferation inhibition, cells were cultured for 48 h after the irradiation and [ 3 H] thymidine was pulsed for 4 h before harvesting. We statistically analyzed the data for quantitative evaluation of radiation risk. While dose and dose rate relationship cultured within one month followed MOE model in cell lines holding wild-type DNA repair system, dose rate effect was greatly impaired in DNA repair-deficient cell lines

  13. Cell survival curves deduced from non-quantitative reactions of skin, intestinal mucosa and lung

    International Nuclear Information System (INIS)

    Dutreix, J.; Wambersie, A.

    1975-01-01

    The shape of the cell survival curve for the cell population relevant to some biological effects has been derived from the comparison of the total doses which result in the same biological effect for two irradiations delivered with N and 2N fractions in the same overall time. They show an initial slope which is interpreted as related to directly lethal, i.e. 'one-hit' or 'irreparable' events. The ratio of the initial slope and the slope at a dose D gives the contribution of the cell killing by directly lethal events relative to cell killing by accumulation of sublethal events. The bioligical effects which have been studied are: (i) dry desquamation of the skin of C 3 H mice and patients; (ii) intestinal death of BALB/c mice; and (iii) lung death of C 3 H mice. The shape of the cell survival curve has been found to be similar for skin desquamation and for intestinal death with a large contribution of lethal events, at single doses of 1000 rad. For lung death the initial tangent has a smaller slope and the shoulder is broader; this is interpreted as a relatively smaller contribution of lethal events with respect to accumulation of sublethal events. (author)

  14. A Biphasic Ligand Exchange Reaction on Cdse Nanoparticles: Introducing Undergraduates to Functionalizing Nanoparticles for Solar Cells

    Science.gov (United States)

    Zemke, Jennifer M.; Franz, Justin

    2016-01-01

    Semiconductor nanoparticles, including cadmium selenide (CdSe) particles, are attractive as light harvesting materials for solar cells. In the undergraduate laboratory, the size-tunable optical and electronic properties can be easily investigated; however, these nanoparticles (NPs) offer another platform for application-based tunability--the NP…

  15. "Hold the Phone!": Cell Phone Use and Partner Reaction among University Students

    Science.gov (United States)

    Beaver, Tiffany; Knox, David; Zusman, Marty E.

    2010-01-01

    Analysis of survey data from 995 undergraduates at a large southeastern university revealed that 93% reported owning a cell phone and a statistically significant difference between women and men (95% versus 91.2%) and between Whites (95.1%) and Blacks (87.7%). In addition, Blacks were twice as likely as Whites to be bothered by their partner's use…

  16. Adaptive and innate immune reactions regulating mast cell activation: from receptor-mediated signaling to responses

    DEFF Research Database (Denmark)

    Tkaczyk, Christine; Jensen, Bettina M; Iwaki, Shoko

    2006-01-01

    differentially activate multiple signaling pathways within the mast cells required for the generation and/or release of inflammatory mediators. Thus, the composition of the suite of mediators released and the physiologic ramifications of these responses are dependent on the stimuli and the microenvironment...

  17. Modified Graphene as Electrocatalyst towards Oxygen Reduction Reaction for Fuel Cells

    International Nuclear Information System (INIS)

    Qazzazie, D; Yurchenko, O; Beckert, M; Mülhaupt, R; Urban, G

    2014-01-01

    This paper reports modified graphene-based materials as metal-free electrocatalysts for oxygen reduction reaction (ORR) with outstanding electrocatalytic activity in alkaline conditions. Nitrogen-doped graphene samples are synthesized by a novel procedure. The defect density in the structure of the prepared materials is investigated by Raman spectroscopy. Further structural characterization by X-ray photoelectron spectroscopy reveals the successful nitrogen doping of graphene. The electrochemical characterization of graphene and nitrogen-doped graphene in 0.1 M KOH solution demonstrates the material's electrocatalytic activity towards ORR. For graphene an onset potential of – 0.175 V vs. Ag/AgCl reference electrode is determined, while for nitrogen-doped graphene the determined onset potential is – 0.160 V. Thus, the electrocatalytic activity of nitrogen-doped graphene towards ORR is enhanced which can be ascribed to the effect of nitrogen doping

  18. Modified Graphene as Electrocatalyst towards Oxygen Reduction Reaction for Fuel Cells

    Science.gov (United States)

    Qazzazie, D.; Beckert, M.; Mülhaupt, R.; Yurchenko, O.; Urban, G.

    2014-11-01

    This paper reports modified graphene-based materials as metal-free electrocatalysts for oxygen reduction reaction (ORR) with outstanding electrocatalytic activity in alkaline conditions. Nitrogen-doped graphene samples are synthesized by a novel procedure. The defect density in the structure of the prepared materials is investigated by Raman spectroscopy. Further structural characterization by X-ray photoelectron spectroscopy reveals the successful nitrogen doping of graphene. The electrochemical characterization of graphene and nitrogen-doped graphene in 0.1 M KOH solution demonstrates the material's electrocatalytic activity towards ORR. For graphene an onset potential of - 0.175 V vs. Ag/AgCl reference electrode is determined, while for nitrogen-doped graphene the determined onset potential is - 0.160 V. Thus, the electrocatalytic activity of nitrogen-doped graphene towards ORR is enhanced which can be ascribed to the effect of nitrogen doping.

  19. Applications of Transport/Reaction Codes to Problems in Cell Modeling; TOPICAL

    International Nuclear Information System (INIS)

    MEANS, SHAWN A.; RINTOUL, MARK DANIEL; SHADID, JOHN N.

    2001-01-01

    We demonstrate two specific examples that show how our exiting capabilities in solving large systems of partial differential equations associated with transport/reaction systems can be easily applied to outstanding problems in computational biology. First, we examine a three-dimensional model for calcium wave propagation in a Xenopus Laevis frog egg and verify that a proposed model for the distribution of calcium release sites agrees with experimental results as a function of both space and time. Next, we create a model of the neuron's terminus based on experimental observations and show that the sodium-calcium exchanger is not the route of sodium's modulation of neurotransmitter release. These state-of-the-art simulations were performed on massively parallel platforms and required almost no modification of existing Sandia codes

  20. Cell phone ringtone, but not landline phone ringtone, affects complex reaction time

    Directory of Open Access Journals (Sweden)

    Radosław Zajdel

    2013-02-01

    Full Text Available Introduction: Legislation systems of most countries prohibited using the handheld mobile phone while driving due to the fact that it disturbs concentration and causes hand involvement. Every phone owner is accustomed to the ringtone of his phone and almost involuntarily endeavors to pick it up or check who calls. This engages one’s psychomotor skills, which in our opinion contributes to the attenuation of reaction time needed for performing other crucial functions. Objectives: The aim of the study was: (1 to evaluate the infl uence of the sound of a ringing mobile phone on the complex reaction time (RT score in healthy subjects (owners, and (2 to check if there are any differences in RT when a landline phone and mobile phone ring. Methods: To assess RT we used our system and protocol of examination, previously validated. The examination conditions were standardized. All tests were performed in the same room with the same light and general acoustic conditions. The test group consisted of 23 women and 24 men, aged 19–24 years. The examination comprised 4 sessions: Training Session (TS during which the subjects were accustomed with the application and sample stimuli, Control Session (CS with no telephone ringing, Landline Session (LS with landline phone ringing, Mobile Session (MS with mobile phone ringing. Results: The median RT in the study population was signifi cantly elongated (p 0.05. Conclusions: We think that the specifi c ‘bond’ between a person and their private phone can signifi cantly disrupt their attention and thus affect the attention-demanding activities.

  1. Ageing, exposure to pollution, and interactions between climate change and local seasons as oxidant conditions predicting incident hematologic malignancy at KINSHASA University clinics, Democratic Republic of CONGO (DRC).

    Science.gov (United States)

    Nkanga, Mireille Solange Nganga; Longo-Mbenza, Benjamin; Adeniyi, Oladele Vincent; Ngwidiwo, Jacques Bikaula; Katawandja, Antoine Lufimbo; Kazadi, Paul Roger Beia; Nzonzila, Alain Nganga

    2017-08-23

    The global burden of hematologic malignancy (HM) is rapidly rising with aging, exposure to polluted environments, and global and local climate variability all being well-established conditions of oxidative stress. However, there is currently no information on the extent and predictors of HM at Kinshasa University Clinics (KUC), DR Congo (DRC). This study evaluated the impact of bio-clinical factors, exposure to polluted environments, and interactions between global climate changes (EL Nino and La Nina) and local climate (dry and rainy seasons) on the incidence of HM. This hospital-based prospective cohort study was conducted at Kinshasa University Clinics in DR Congo. A total of 105 black African adult patients with anaemia between 2009 and 2016 were included. HM was confirmed by morphological typing according to the French-American-British (FAB) Classification System. Gender, age, exposure to traffic pollution and garages/stations, global climate variability (El Nino and La Nina), and local climate (dry and rainy seasons) were potential independent variables to predict incident HM using Cox regression analysis and Kaplan Meier curves. Out of the total 105 patients, 63 experienced incident HM, with an incidence rate of 60%. After adjusting for gender, HIV/AIDS, and other bio-clinical factors, the most significant independent predictors of HM were age ≥ 55 years (HR = 2.4; 95% CI 1.4-4.3; P = 0.003), exposure to pollution and garages or stations (HR = 4.9; 95% CI 2-12.1; P pollution, combined local dry season + La Nina and combined local dry season + El Nino were the most significant predictors of incident hematologic malignancy. These findings highlight the importance of aging, pollution, the dry season, El Nino and La Nina as related to global warming as determinants of hematologic malignancies among African patients from Kinshasa, DR Congo. Cancer registries in DRC and other African countries will provide more robust database for future researches on

  2. Determination of Se at low concentration in coal by collision/reaction cell technology inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Henn, Alessandra S.; Rondan, Filipe S.; Mesko, Marcia F.; Mello, Paola A.; Perez, Magali; Armstrong, Joseph; Bullock, Liam A.; Parnell, John; Feldmann, Joerg; Flores, Erico M. M.

    2018-05-01

    A method is proposed for the determination of selenium at low concentration in coal by collision/reaction cell technology inductively coupled plasma mass spectrometry (CRC-ICP-MS). Samples were decomposed by high pressure microwave-assisted wet digestion (MAWD) using 250 mg of coal, a mixture of 5 mL of 14.4 mol L-1 HNO3 and 1 mL of 40% HF and 70 min of heating program (200 °C and 40 bar). Hydrogen gas used in the collision/reaction cell was investigated to minimize the argon-based interferences at m/z 77, 78 and 80. The rejection parameter (RPq) and the H2 gas flow rate were set to 0.45 and 4.8 mL min-1, respectively. The use of H2 in the cell resulted in other polyatomic interferences, such as 76Ge1H+, 79Br1H+ and 81Br1H+, which impaired Se determination using 77Se, 80Se and 82Se isotopes, thus Se determination was carried out by monitoring only 78Se isotope. Selenium was determined in certified reference materials of coal (NIST 1635 and SARM 20) and an agreement better than 95% was observed between the results obtained by CRC-ICP-MS and the certified values. Under optimized conditions, the instrumental limit of detection was 0.01 μg L-1 and the method limit of detection was 0.01 μg g-1, which was suitable for Se determination at very low concentration in coal.

  3. Powerful strategy for polymerase chain reaction-based clonality assessment in T-cell malignancies Report of the BIOMED-2 Concerted Action BHM4 CT98-3936

    NARCIS (Netherlands)

    Brüggemann, M.; White, H.; Gaulard, P.; Garcia-Sanz, R.; Gameiro, P.; Oeschger, S.; Jasani, B.; Ott, M.; Delsol, G.; Orfao, A.; Tiemann, M.; Herbst, H.; Langerak, A. W.; Spaargaren, M.; Moreau, E.; Groenen, P. J. T. A.; Sambade, C.; Foroni, L.; Carter, G. I.; Hummel, M.; Bastard, C.; Davi, F.; Delfau-Larue, M.-H.; Kneba, M.; van Dongen, J. J. M.; Beldjord, K.; Molina, T. J.

    2007-01-01

    Polymerase chain reaction (PCR) assessment of clonal T-cell receptor (TCR) and immunoglobulin (Ig) gene rearrangements is an important diagnostic tool in mature T-cell neoplasms. However, lack of standardized primers and PCR protocols has hampered comparability of data in previous clonality studies.

  4. Histopathology and immune histochemistry of red tattoo reactions. Interface dermatitis is the lead pathology, with increase in T-lymphocytes and Langerhans cells suggesting an allergic pathomechanism.

    Science.gov (United States)

    Høgsberg, T; Thomsen, B M; Serup, J

    2015-11-01

    The majority of tattoo reactions are affiliated to red pigmented areas and often suspected to be allergic in nature. A sizeable series of biopsies of such reactions has not previously been performed. The aim of this study was to type and grade epidermal and dermal changes in tattoo reactions to red/red nuances by microscopy and immunochemistry relevant for the assessment of a possible allergic pathomechanism. Skin biopsies were taken from red tattoo reactions, graded by conventional microscopy and stained for T and B-lymphocytes, Langerhans cells, macrophages and tumour necrosis factor (TNF)-α. The study included 19 biopsies from 19 patients. The culprit colours were red/pink (n = 15) and purple/bordeaux (n = 4). Interface dermatitis was clearly the lead pathology found in 78% of samples, overlapped with granulomatous (in 32%) and pseudolymphomatous reaction patterns (in 32%). Epidermal hyperkeratosis (in 89%) was common as was leakage of red pigment across the dermo-epidermal junction, with transepidermal elimination (in 28%). The dermal cellular infiltration was dominated by T-lymphocytes (in 100%), Langerhans cells (in 95%) and macrophages (in 100%). TNF-α was common. The predominant histological pattern of chronic tattoo reactions in red/red nuances is interface dermatitis. T-lymphocytes and Langerhans cells are increased suggesting an allergic pathomechanism. TNF-α may contribute to reactions. In many cases, overlapping reactive patterns were identified. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Synthesis of Chitin Oligosaccharides Using Dried Stenotrophomonas maltophilia Cells Containing a Transglycosylation Reaction-Catalyzing β-N-Acetylhexosaminidase as a Whole-Cell Catalyst.

    Science.gov (United States)

    Uehara, Asaki; Takahashi, Narumi; Moriyama, Mei; Hirano, Takako; Hakamata, Wataru; Nishio, Toshiyuki

    2018-02-01

    Bacterial strain NYT501, which we previously isolated from soil, was identified as Stenotrophomonas maltophilia, and it was confirmed that this strain produces an intracellular β-N-acetylhexosaminidase exhibiting transglycosylation activity. Several properties of this enzyme were characterized using a partially purified enzyme preparation. Using N,N'-diacetylchitobiose (GlcNAc) 2 and N,N',N″-triacetylchitotriose (GlcNAc) 3 as substrates and dried cells of this bacterium as a whole-cell catalyst, chitin oligosaccharides of higher degrees of polymerization were synthesized. (GlcNAc) 3 was generated from (GlcNAc) 2 as the major transglycosylation product, and a certain amount of purified sample of the trisaccharide was obtained. By contrast, in the case of the reaction using (GlcNAc) 3 as a substrate, the yield of higher-degree polymerization oligosaccharides was comparatively low.

  6. Graft-versus-host reaction and immune function. III. Functional pre-T cells in the bone marrow of graft-versus-host-reactive mice displaying T cell immunodeficiency

    International Nuclear Information System (INIS)

    Seddik, M.; Seemayer, T.A.; Lapp, W.S.

    1986-01-01

    Studies were performed to determine whether pre-T cells develop normally in the bone marrow of mice displaying thymic dysplasia and T cell immunodeficiency as a consequence of a graft-versus-host (GVH) reaction. GVH reactions were induced in CBAxAF1 mice by the injection of A strain lymphoid cells. To test for the presence of pre-T cells in GVH-reactive mice, bone marrow from GVH-reactive mice (GVHBM) was injected into irradiated syngeneic F1 mice and 30-40 days later thymic morphology and function were studied. Morphology studies showed nearly normal thymic architectural restoration; moreover, such glands contained normal numbers of Thy-1-positive cells. Functional pre-T cells were evaluated by transferring thymocytes from the irradiated GVHBM-reconstituted mice into T-cell-deprived mice. These thymocytes reconstituted allograft reactivity, T helper cell function and Con A and PHA mitogen responses of T-cell-deprived mice. These results suggest that the pre-T cell population in the bone marrow is not affected by the GVH reaction. Therefore, the T cell immunodeficiency associated with the GVH reaction is not due to a deficiency of pre-T cells in the bone marrow but is more likely associated with GVH-induced thymic dysplasia

  7. Electrochemically Promoted Organic Isomerization Reactions at Polymer Electrolyte Fuel Cell Cathodes

    Science.gov (United States)

    2011-01-04

    fuel cells ( PEMFCs ) incorporate an ionomer membrane (e.g., Nafion 117) for support of electro- catalytic layers and proton conduction between the...central to PEMFC electrocatalysis. For example, a spin coated Nafion layer on polycrystalline Pt enhances electrocatalysis.7,8 Little is known about...CO Poisoning Effect in PEMFCs Operational at Temperatures up to 200°C. Journal of the Electrochemical Society, 2003. 150(12): p. A1599-A1605. 21

  8. The reaction of Lupinus angustifolius L. root meristematic cell nucleoli to lead.

    Science.gov (United States)

    Balcerzak, Lucja; Glińska, Sława; Godlewski, Mirosław

    2011-04-01

    The effect of 2-48 h treatment of Lupinus angustifolius L. roots with lead nitrate at the concentration of 10(-4) M on the nucleoli in meristematic cells was investigated. In the lead presence the number of ring-shaped as well as segregated nucleoli increased especially after 12-48 h of treatment, while spindle-shaped nucleoli appeared after 24 h and 48 h. Lead presence also increased the frequency of cells with silver-stained particles in the nucleus and the number of these particles especially from the 12th hour of treatment. It was accompanied by significant decline of nucleolar area. Analysis of these cells in transmission electron microscope confirmed the presence of ring-shaped and segregated nucleoli. Moreover, electron microscopy revealed compact structure nucleoli without granular component. Additionally, one to three oval-shaped fibrillar structures attached to nucleolus or lying free in the nucleoplasm were visible. The possible mechanism of lead toxicity to the nucleolus is briefly discussed.

  9. Differential cell reaction upon Toll-like receptor 4 and 9 activation in human alveolar and lung interstitial macrophages

    Directory of Open Access Journals (Sweden)

    Meyerhans Andreas

    2010-09-01

    Full Text Available Abstract Background Investigations on pulmonary macrophages (MΦ mostly focus on alveolar MΦ (AM as a well-defined cell population. Characteristics of MΦ in the interstitium, referred to as lung interstitial MΦ (IM, are rather ill-defined. In this study we therefore aimed to elucidate differences between AM and IM obtained from human lung tissue. Methods Human AM and IM were isolated from human non-tumor lung tissue from patients undergoing lung resection. Cell morphology was visualized using either light, electron or confocal microscopy. Phagocytic activity was analyzed by flow cytometry as well as confocal microscopy. Surface marker expression was measured by flow cytometry. Toll-like receptor (TLR expression patterns as well as cytokine expression upon TLR4 or TLR9 stimulation were assessed by real time RT-PCR and cytokine protein production was measured using a fluorescent bead-based immunoassay. Results IM were found to be smaller and morphologically more heterogeneous than AM, whereas phagocytic activity was similar in both cell types. HLA-DR expression was markedly higher in IM compared to AM. Although analysis of TLR expression profiles revealed no differences between the two cell populations, AM and IM clearly varied in cell reaction upon activation. Both MΦ populations were markedly activated by LPS as well as DNA isolated from attenuated mycobacterial strains (M. bovis H37Ra and BCG. Whereas AM expressed higher amounts of inflammatory cytokines upon activation, IM were more efficient in producing immunoregulatory cytokines, such as IL10, IL1ra, and IL6. Conclusion AM appear to be more effective as a non-specific first line of defence against inhaled pathogens, whereas IM show a more pronounced regulatory function. These dissimilarities should be taken into consideration in future studies on the role of human lung MΦ in the inflammatory response.

  10. Large-scale multiplex polymerase chain reaction assay for diagnosis of viral reactivations after allogeneic hematopoietic stem cell transplantation.

    Science.gov (United States)

    Inazawa, Natsuko; Hori, Tsukasa; Hatakeyama, Naoki; Yamamoto, Masaki; Yoto, Yuko; Nojima, Masanori; Suzuki, Nobuhiro; Shimizu, Norio; Tsutsumi, Hiroyuki

    2015-08-01

    Viral reactivations following hematopoietic stem cell transplantation are thought to result from the breakdown of both cell-mediated and humoral immunity. As a result, many viruses could be reactivated individually or simultaneously. Using a multiplex polymerase chain reaction (PCR), we prospectively examined many kinds of viral DNAs at a time in 105 patients who underwent allogeneic hematopoietic stem cell transplantation. In total, 591 whole blood samples were collected weekly from pre- to 42 days post-transplantation and the following 13 viruses were tested; herpes simplex virus 1 (HSV-1), HSV-2, varicella-zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpes virus 6 (HHV-6), HHV-7, HHV-8, adenovirus, BK virus (BKV), JC virus (JCV), parvovirus B19, and hepatitis B virus (HBV). Several viral DNAs were detected in 12 patients before hematopoietic stem cell transplantation. The detection rate gradually increased after transplantation and peaked at 21 days. The most frequently detected virus was HHV-6 (n = 63; 60.0%), followed by EBV (n = 11; 10.5%), CMV (n = 11; 10.5%), and HHV-7 (n = 9; 8.6%). Adenovirus and HBV were each detected in one patient (1.0%). Detection of HHV-6 DNA was significantly more common among patients undergoing cord blood transplantation or with steroid treatment. EBV DNA tended to be more common in patients treated with anti-thymocyte globulin. Multiplex PCR was useful for detecting many viral reactivations after hematopoietic stem cell transplantation, simultaneously. Cord blood transplantation, steroid treatment, or anti-thymocyte globulin use was confirmed to be risk factors after transplantation. © 2015 Wiley Periodicals, Inc.

  11. Fluoride sample matrices and reaction cells — new capabilities for isotope measurements in accelerator mass spectrometry

    Directory of Open Access Journals (Sweden)

    Eliades J.

    2012-04-01

    Full Text Available Two new techniques, which extend the range of elements that can be analyzed by Accelerator Mass Spectrometry (AMS, and which increase its isobar selection capabilities, have been recently introduced. The first consists of embedding the sample material in a fluoride matrix (e.g. PbF2, which facilitates the production, in the ion source, of fluoride molecular anions that include the isotope of interest. In addition to forming anions with large electron binding energies and thereby increasing the range of analysable elements, in many cases by selection of a molecular form with a particular number of fluorine atoms, some isobar discrimination can be obtained. The second technique, for the significant reduction of atomic isobar interferences, is used following mass selection of the rare isotope. It consists of the deceleration, cooling and reaction of the rare mass beam with a gas, selected so that unwanted isobars are greatly attenuated in comparison with the isotope of interest. Proof of principle measurements for the analysis of 36C1 and 41Ca have provided encouraging results and work is proceeding on the integration of these techniques in a new AMS system planned for installation in late 2012 at the University of Ottawa.

  12. Optimization of the Pd-Fe-Mo Catalysts for Oxygen Reduction Reaction in Proton-Exchange Membrane Fuel Cells

    International Nuclear Information System (INIS)

    Lee, Yeayeon; Jang, Jeongseok; Lee, Jin Goo; Jeon, Ok Sung; Kim, Hyeong Su; Hwang, Ho Jung; Shul, Yong Gun

    2016-01-01

    Highlights: • Pd-Mo-Fe catalysts show high catalytic activity and stability for oxygen-reduction reactions in acid media. • The optimum compositions were 7.5:1.5:1.0 for Pd-Fe-Mo, and the optimum temperatures were 500 °C. • The Pd-Fe-Mo catalysts were successfully applied to the PEMFC cathode, showing ∼500 mA cm −1 at 0.6 V. • The lattice constant was strongly related to the activity and stability of the catalysts for oxygen-reduction reactions. - Abstract: Highly active and durable non-platinum catalysts for oxygen-reduction reaction (ORR) have been developed for energy conversion devices such as proton-exchange membrane fuel cells (PEMFCs). In this study, Pd-Fe-Mo catalyst is reported as a non-platinum catalyst for ORR. The atomic ratio and annealing temperatures are controlled on the catalysts to understand interplay between their physical and chemical properties and electrochemical activities. The Pd-Fe-Mo catalyst optimized with 7.5:1.5:1.0 of the atomic ratio and 500 °C of the annealing temperature shows 32.18 mA mg −1 PGM (PGM: platinum group metal) of the kinetic current density at 0.9 V for ORR, which is comparable to that of commercial Pt/C catalyst. The current density is degraded to 6.20 mA mg −1 PGM after 3000 cycling of cyclic voltammetry, but it is greatly enhanced value compared to other non-platinum catalysts. In actual application to PEMFCs, the 20% Pd-Fe-Mo catalyst supported on carbons exhibits a high performance of 506 mA cm −2 at 0.6 V. The results suggest that the Pd-Fe-Mo catalyst can be a good candidate for non-platinum ORR catalysts.

  13. A chip-type thin-layer electrochemical cell coupled with capillary electrophoresis for online separation of electrode reaction products

    Energy Technology Data Exchange (ETDEWEB)

    He, Jian-Bo, E-mail: jbhe@hfut.edu.cn; Cui, Ting; Zhang, Wen-Wen; Deng, Ning

    2013-07-05

    Graphical abstract: -- Highlights: •A new coupling of thin-layer electrolysis with capillary electrophoresis (CE). •Rapid electrolysis, direct sampling followed by online CE separation. •At least 13 products of quercetin oxidation were separated. •Thermodynamic and kinetic parameters were determined from CE peak areas. -- Abstract: A coupling technique of thin-layer electrolysis with high-performance capillary electrophoresis/UV–vis technique(EC/HPCE/UV–vis) is developed for online separation and determination of electrode reaction products. A chip-type thin-layer electrolytic (CTE) cell was designed and fabricated, which contains a capillary channel and a background electrolyte reservoir, allowing rapid electrolysis, direct sampling and online electrophoretic separation. This chip-type setup was characterized based on an electrophoresis expression of Nernst equation that was applied to the redox equilibrium of o-tolidine at different potentials. The utility of the method was demonstrated by separating and determining the electro-oxidation products of quercetin in different pH media. Two main products were always found in the studied time, potential and pH ranges. The variety of products increased not only with increasing potential but also with increasing pH value, and in total, at least 13 products were observed in the electropherograms. This work illustrates a novel example of capillary electrophoresis used online with thin-layer electrolysis to separate and detect electrode reaction products.

  14. A chip-type thin-layer electrochemical cell coupled with capillary electrophoresis for online separation of electrode reaction products

    International Nuclear Information System (INIS)

    He, Jian-Bo; Cui, Ting; Zhang, Wen-Wen; Deng, Ning

    2013-01-01

    Graphical abstract: -- Highlights: •A new coupling of thin-layer electrolysis with capillary electrophoresis (CE). •Rapid electrolysis, direct sampling followed by online CE separation. •At least 13 products of quercetin oxidation were separated. •Thermodynamic and kinetic parameters were determined from CE peak areas. -- Abstract: A coupling technique of thin-layer electrolysis with high-performance capillary electrophoresis/UV–vis technique(EC/HPCE/UV–vis) is developed for online separation and determination of electrode reaction products. A chip-type thin-layer electrolytic (CTE) cell was designed and fabricated, which contains a capillary channel and a background electrolyte reservoir, allowing rapid electrolysis, direct sampling and online electrophoretic separation. This chip-type setup was characterized based on an electrophoresis expression of Nernst equation that was applied to the redox equilibrium of o-tolidine at different potentials. The utility of the method was demonstrated by separating and determining the electro-oxidation products of quercetin in different pH media. Two main products were always found in the studied time, potential and pH ranges. The variety of products increased not only with increasing potential but also with increasing pH value, and in total, at least 13 products were observed in the electropherograms. This work illustrates a novel example of capillary electrophoresis used online with thin-layer electrolysis to separate and detect electrode reaction products

  15. Bed net ownership, use and perceptions among women seeking antenatal care in Kinshasa, Democratic Republic of the Congo (DRC: Opportunities for improved maternal and child health

    Directory of Open Access Journals (Sweden)

    Tabala Martine

    2008-09-01

    Full Text Available Abstract Background To describe malaria knowledge, attitudes toward malaria and bed net use, levels of ownership and use of bed nets, and factors associated with ownership and use among pregnant women attending their first antenatal care (ANC visit in Kinshasa, DRC. Methods Women attending their first ANC visit at one maternity in Kinshasa were recruited to take part in a study where they were given free insecticide treated bed nets (ITNs and then followed up at delivery and 6 months post delivery to assess ITN use. This study describes the baseline levels of bed net ownership and use, attitudes towards net use and factors associated with net use Results Among 351 women interviewed at baseline, 115 (33% already owned a bed net and 86 (25% reported to have slept under the net the previous night. Cost was reported as the reason for not owning a net by 48% of the 236 women who did not own one. In multivariable analyses, women who had secondary school or higher education were 3.4 times more likely to own a net (95% CI 1.6–7.3 and 2.8 times more likely to have used a net (95% CI 1.3–6.0 compared to women with less education Conclusion Distribution of ITNs in antenatal clinics in this setting is needed and feasible. The potential for ITN use by this target population is high.

  16. Human Bone Marrow-Derived Mesenchymal Cell Reactions to 316L Stainless Steel: An in Vitro Study on Cell Viability and Interleukin-6 Expression

    Science.gov (United States)

    Anwar, Iwan Budiwan; Santoso, Asep; Saputra, Eko; Ismail, Rifky; Jamari, J.; Van der Heide, Emile

    2017-01-01

    Purpose: Human bone marrow-derived mesenchymal cell (hBMC) reactions to 316L stainless steel (316L-SS) have never been evaluated. The objective of this study was to assess cell viability and interleukin-6 expression of hBMC cultures upon treatment with a 316L-SS implant. Methods: A cytotoxicity analysis was conducted with a 3-(4,5-dimethylthiazol 2-yl)-2,5-diphenyltetrazolium (MTT) assay after a period of 24, 48 and 72 hours of incubation. Expression of interleukin-6 was measured using enzyme-linked immunosorbent assay (ELISA). Results: Cell viability measurement was performed via IC50 formula. All treatment group showed a > 50 % cell viability with a range of 56,5 - 96,9 % at 24 hours, 51,8-77,3% at 48 hours and 70,1- 120 % at 72 hours. Interleukin-6 expression was downregulated subsequent to treatment with 316L-SS compared to the control group. Conclusion: We found that 316L-SS did not exhibit toxicity towards hBMC culture. PMID:28761837

  17. SOS reaction kinetics of bacterial cells induced by ultraviolet radiation and α particles

    International Nuclear Information System (INIS)

    Bonev, M.; Kolev, S.

    2000-01-01

    It is the purpose of the work to apply the SOS lux test for detecting α particles, as well as to study the SOS system kinetics. Two strains with plasmid pPLS-1 are used: wild type C600 lux and its isogen lysogen with α prophage one. Irradiation is done on dacron nuclear filters. The source of α particles is Am 241 with power 5 Gy/min, and the ultraviolet source - a lamp emitting rays with wave length 254 nm. The light yield is measured by installations made up of scintilometer VA-S-968, High-voltage electric power, and one channel analyzer Strahlugsmessgerat 20046. The SOS lux text is based on the recombinant plasmid pPLS-1 which is a derivative of pBR322 where the lux gene is set under the control of an SOS promoter. E coly recA + strains containing the construction produce considerable amount of photons in the visible zone following treatment with agents damaging the DNA of cells. The kinetic curves of SOS response are obtained after irradiation with α particles and UV rays. DNA damaging agents cause an increase in the initial SOS response rate in the range od smaller doses, and a decrease reaching to block of the one in the high doses range. The light yield of lysogenic cells is lower. As compared to nonelysogene ones. DNA damage caused by α particles are more difficult to repair as compared to pyrimidine dimers. (author)

  18. Comparison of cathode catalyst binders for the hydrogen evolution reaction in microbial electrolysis cells

    KAUST Repository

    Ivanov, Ivan

    2017-06-02

    Nafion is commonly used as a catalyst binder in many types of electrochemical cells, but less expensive binders are needed for the cathodes in microbial electrolysis cells (MECs) which are operated in neutral pH buffers, and reverse electrodialysis stacks (RED),which use thermolytic solutions such as ammonium bicarbonate. Six different binders were examined based on differences in ion exchange properties (anionic: Nafion, BPSH20, BPSH40, S-Radel; cationic: Q-Radel; and neutral: Radel, BAEH) and hydrophobicity based on water uptake (0%, Radel; 17–56% for the other binders). BPSH40 had similar performance to Nafion based on steady-state polarization single electrode experiments in a neutral pH phosphate buffer, and slightly better performance in ammonium bicarbonate. Three different Mo-based catalysts were examined as alternatives to Pt, with MoB showing the best performance under steady-state polarization. In MECs, MoB/BPSH40 performed similarly to Pt with Nafion or Radel binders. The main distinguishing feature of the BPSH40 was that it is very hydrophilic, and thus it had a greater water content (56%) than the other binders (0–44%). These results suggest the binders for hydrogen evolution in MECs should be designed to have a high water content without sacrificing ionic or electronic conductivity in the electrode.

  19. Gas driven displacement in a Hele-Shaw cell with chemical reaction

    Science.gov (United States)

    White, Andrew; Ward, Thomas

    2011-11-01

    Injecting a less viscous fluid into a more viscous fluid produces instabilities in the form of fingering which grow radially from the less viscous injection point (Saffman & Taylor, Proc. R. Soc. Lon. A, 1958). For two non-reacting fluids in a radial Hele-Shaw cell the ability of the gas phase to penetrate the liquid phase is largely dependent on the gap height, liquid viscosity and gas pressure. In contrast combining two reactive fluids such as aqueous calcium hydroxide and carbon dioxide, which form a precipitate, presents a more complex but technically relevant system. As the two species react calcium carbonate precipitates and increases the aqueous phase visocosity. This change in viscosity may have a significant impact on how the gas phase penetrates the liquid phase. Experimental are performed in a radial Hele-Shaw cell with gap heights O(10-100) microns by loading a single drop of aqueous calcium hydroxide and injecting carbon dioxide into the drop. The calcium hydroxide concentration, carbon dioxide pressure and gap height are varied and images of the gas penetration are analyzed to determine residual film thickness and bursting times.

  20. Comparison of cathode catalyst binders for the hydrogen evolution reaction in microbial electrolysis cells

    KAUST Repository

    Ivanov, Ivan; Ahn, YongTae; Poirson, Thibault; Hickner, Michael A.; Logan, Bruce

    2017-01-01

    Nafion is commonly used as a catalyst binder in many types of electrochemical cells, but less expensive binders are needed for the cathodes in microbial electrolysis cells (MECs) which are operated in neutral pH buffers, and reverse electrodialysis stacks (RED),which use thermolytic solutions such as ammonium bicarbonate. Six different binders were examined based on differences in ion exchange properties (anionic: Nafion, BPSH20, BPSH40, S-Radel; cationic: Q-Radel; and neutral: Radel, BAEH) and hydrophobicity based on water uptake (0%, Radel; 17–56% for the other binders). BPSH40 had similar performance to Nafion based on steady-state polarization single electrode experiments in a neutral pH phosphate buffer, and slightly better performance in ammonium bicarbonate. Three different Mo-based catalysts were examined as alternatives to Pt, with MoB showing the best performance under steady-state polarization. In MECs, MoB/BPSH40 performed similarly to Pt with Nafion or Radel binders. The main distinguishing feature of the BPSH40 was that it is very hydrophilic, and thus it had a greater water content (56%) than the other binders (0–44%). These results suggest the binders for hydrogen evolution in MECs should be designed to have a high water content without sacrificing ionic or electronic conductivity in the electrode.

  1. Reference genes for gene expression analysis by real-time reverse transcription polymerase chain reaction of renal cell carcinoma.

    Science.gov (United States)

    Bjerregaard, Henriette; Pedersen, Shona; Kristensen, Søren Risom; Marcussen, Niels

    2011-12-01

    Differentiation between malignant renal cell carcinoma and benign oncocytoma is of great importance to choose the optimal treatment. Accurate preoperative diagnosis of renal tumor is therefore crucial; however, existing imaging techniques and histologic examinations are incapable of providing an optimal differentiation profile. Analysis of gene expression of molecular markers is a new possibility but relies on appropriate standardization to compare different samples. The aim of this study was to identify stably expressed reference genes suitable for the normalization of results extracted from gene expression analysis of renal tumors. Expression levels of 8 potential reference genes (ATP5J, HMBS, HPRT1, PPIA, TBP, 18S, GAPDH, and POLR2A) were examined by real-time reverse transcription polymerase chain reaction in tumor and normal tissue from removed kidneys from 13 patients with renal cell carcinoma and 5 patients with oncocytoma. The expression levels of genes were compared by gene stability value M, average gene stability M, pairwise variation V, and coefficient of variation CV. More candidates were not suitable for the purpose, but a combination of HMBS, PPIA, ATP5J, and TBP was found to be the best combination with an average gene stability value M of 0.9 and a CV of 0.4 in the 18 tumors and normal tissues. A combination of 4 genes, HMBS, PPIA, ATP5J, and TBP, is a possible reference in renal tumor gene expression analysis by reverse transcription polymerase chain reaction. A combination of four genes, HMBS, PPIA, ATP5J and TBP, being stably expressed in tissues from RCC is possible reference genes for gene expression analysis.

  2. Different DNA methylation patterns detected by the Amplified Methylation Polymorphism Polymerase Chain Reaction (AMP PCR) technique among various cell types of bulls

    OpenAIRE

    Phutikanit, Nawapen; Suwimonteerabutr, Junpen; Harrison, Dion; D'Occhio, Michael; Carroll, Bernie; Techakumphu, Mongkol

    2010-01-01

    Abstract Background The purpose of this study was to apply an arbitrarily primed methylation sensitive polymerase chain reaction (PCR) assay called Amplified Methylation Polymorphism Polymerase Chain Reaction (AMP PCR) to investigate the methylation profiles of somatic and germ cells obtained from Holstein bulls. Methods Genomic DNA was extracted from sperm, leukocytes and fibroblasts obtained from three bulls and digested with a methylation sensitive endonuclease (HpaII). The native genomic ...

  3. Polymerase chain reaction assay for the detection of Bacillus cereus group cells

    DEFF Research Database (Denmark)

    Hansen, Bjarne Munk; Leser, Thomas D.; Hendriksen, Niels Bohse

    2001-01-01

    of the B. cereus group in food and in the environment. Using 16S rDNA as target, a PCR assay for the detection of B. cereus group cells has been developed. Primers specific for the 16S rDNA of the B. cereus group bacteria were selected and used in combination with consensus primers for 165 rDNA as internal...... PCR procedure control. The PCR procedure was optimized with respect to annealing temperature. When DNA from the B. cereus group bacteria was present, the PCR assay yielded a B. cereus specific fragment, while when non-B. cereus prokaryotic DNA was present, the consensus 165 rDNA primers directed...

  4. Palladium-based electrocatalysts for ethanol oxidation reaction in alkaline direct ethanol fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Leticia Poras Reis de; Amico, Sandro Campos; Malfatti, Celia de Fraga, E-mail: leticiamoraes@usp.br [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre (Brazil); Matos, Bruno R.; Santiago, Elisabete Inacio; Fonseca, Fabio Coral [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2016-07-01

    Full text: Direct ethanol fuel cells require adequate electrocatalysts to promote the carbon carbon cleavage of ethanol molecule. Typical electrocatalysts are based on platinum, which have shown improved activity in acidic media. However, Pt-based catalysts have high cost and are easily deactivated by CO poisoning. Therefore, novel catalysts have been developed, and among then, palladium-based materials have shown promising results for the oxidation of ethanol in alkaline media. The present study reports on the performance of alkaline direct ethanol fuel cell (ADEFC) by using carbon-supported Pd, PdSn, PdNi, and PdNiSn produced by impregnation-reduction of the metallic precursors. The effect of chemical functionalization by acid treatment of the carbon support (Vulcan) was investigated. The electrocatalysts were studied by thermogravimetric analysis (TGA), X-rays diffraction (XRD), transmission electron microscopy (TEM), cyclic voltammetry (CV), and ADEFC tests. TGA measurements of functionalized Vulcan evidenced the characteristic weight losses attributed to the presence of surface functional groups due to the acid treatment. A high degree of alloying between Pd and Sn was inferred from XRD data, whereas in both PdNi and PdNiSn, Ni occurs mostly segregated in the oxide form. TEM analyses indicated agglomeration of Pd and PdSn particles, whereas a more uniform particle distribution was observed for PdNi and PdNiSn samples. CV curves showed that the peak potential for the oxidation of ethanol shifts towards negative values for all samples supported on functionalized Vulcan indicating that ethanol oxidation is facilitated. Microstructural and electrochemical features were confirmed by ADEFC tests, which revealed that the highest open circuit voltage and maximum power density were achieved for PdNiSn electrocatalysts supported on functionalized Vulcan with uniform particle distribution and improved triple phase boundaries. (author)

  5. Palladium-based electrocatalysts for ethanol oxidation reaction in alkaline direct ethanol fuel cell

    International Nuclear Information System (INIS)

    Moraes, Leticia Poras Reis de; Amico, Sandro Campos; Malfatti, Celia de Fraga; Matos, Bruno R.; Santiago, Elisabete Inacio; Fonseca, Fabio Coral

    2016-01-01

    Full text: Direct ethanol fuel cells require adequate electrocatalysts to promote the carbon carbon cleavage of ethanol molecule. Typical electrocatalysts are based on platinum, which have shown improved activity in acidic media. However, Pt-based catalysts have high cost and are easily deactivated by CO poisoning. Therefore, novel catalysts have been developed, and among then, palladium-based materials have shown promising results for the oxidation of ethanol in alkaline media. The present study reports on the performance of alkaline direct ethanol fuel cell (ADEFC) by using carbon-supported Pd, PdSn, PdNi, and PdNiSn produced by impregnation-reduction of the metallic precursors. The effect of chemical functionalization by acid treatment of the carbon support (Vulcan) was investigated. The electrocatalysts were studied by thermogravimetric analysis (TGA), X-rays diffraction (XRD), transmission electron microscopy (TEM), cyclic voltammetry (CV), and ADEFC tests. TGA measurements of functionalized Vulcan evidenced the characteristic weight losses attributed to the presence of surface functional groups due to the acid treatment. A high degree of alloying between Pd and Sn was inferred from XRD data, whereas in both PdNi and PdNiSn, Ni occurs mostly segregated in the oxide form. TEM analyses indicated agglomeration of Pd and PdSn particles, whereas a more uniform particle distribution was observed for PdNi and PdNiSn samples. CV curves showed that the peak potential for the oxidation of ethanol shifts towards negative values for all samples supported on functionalized Vulcan indicating that ethanol oxidation is facilitated. Microstructural and electrochemical features were confirmed by ADEFC tests, which revealed that the highest open circuit voltage and maximum power density were achieved for PdNiSn electrocatalysts supported on functionalized Vulcan with uniform particle distribution and improved triple phase boundaries. (author)

  6. Betalactam antibiotics affect human dendritic cells maturation through MAPK/NF-kB systems. Role in allergic reactions to drugs

    International Nuclear Information System (INIS)

    Lopez, Soledad; Gomez, Enrique; Torres, Maria J.; Pozo, David; Fernandez, Tahia D.; Ariza, Adriana; Sanz, Maria L.; Blanca, Miguel; Mayorga, Cristobalina

    2015-01-01

    The mechanisms leading to drug allergy in predisposed patients, especially those related to T-cell-mediated drug hypersensitivity, are not well understood. A key event in allergic reactions to drugs is the maturation process undergone by dendritic cells (DCs). Although amoxicillin (AX) has been reported to interact and maturate DCs from patients with AX-induced delayed-type hypersensitivity, the cell signaling pathways related to AX-mediated DC maturation have not been elucidated. We sought to determine the role of the MAPK and NF-κΒ pathways on AX-induced DC maturation and functional status. For that purpose, in monocyte-derived-DCs from AX-delayed allergic patients and tolerant subjects, we analyzed the activation pattern of p38MAPK, JNK, and ERK signaling and the NF-κB, maturation markers as well as endocytosis and allostimulatory capacities driven by AX-stimulated-DCs. Our data reveal that AX induces an increase in the phosphorylation levels of the three MAPKsand activated NF-κB in DCs from allergic patients. Moreover, the inhibition of these pathways prevents the up-regulation of surface molecules induced by AX. Additionally, we observed that the allostimulatory capacity and the endocytosis down-regulation in AX-stimulated-DCs from allergic patients depend on JNK and NF-κB activities. Taken together, our data shed light for the first time on the main signaling pathways involved in DC maturation from AX-delayed allergic patient. - Highlights: • The cell signaling pathways related to drug-mediated DC maturation were tested. • Amoxicillin induces activation of MAPK and NF-κB in DCs from allergic patients. • The inhibition of these pathways prevents the up-regulation of DC surface molecules. • Their allostimulatory and endocytosis capacities depend on JNK and NF-κB activities. • The low involvement of p38-MAPK could be the cause of an incomplete DC maturation.

  7. Betalactam antibiotics affect human dendritic cells maturation through MAPK/NF-kB systems. Role in allergic reactions to drugs

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Soledad [CABIMER-Andalusian Center for Molecular Biology and Regenerative Medicine, Seville (Spain); Department of Medical Biochemistry, Molecular Biology and Immunology, The University of Seville Medical School, Seville (Spain); Gomez, Enrique [Research Laboratory, IBIMA-Regional University Hospital of Malaga, UMA, Málaga (Spain); Torres, Maria J. [Allergy Service, IBIMA-Regional University Hospital of Malaga, UMA, Málaga (Spain); Pozo, David [CABIMER-Andalusian Center for Molecular Biology and Regenerative Medicine, Seville (Spain); Department of Medical Biochemistry, Molecular Biology and Immunology, The University of Seville Medical School, Seville (Spain); Fernandez, Tahia D.; Ariza, Adriana [Research Laboratory, IBIMA-Regional University Hospital of Malaga, UMA, Málaga (Spain); Sanz, Maria L. [Department of Allergology and Clinical Immunology, University Clinic of Navarra, Pamplona (Spain); Blanca, Miguel [Allergy Service, IBIMA-Regional University Hospital of Malaga, UMA, Málaga (Spain); Mayorga, Cristobalina, E-mail: lina.mayorga@ibima.eu [Research Laboratory, IBIMA-Regional University Hospital of Malaga, UMA, Málaga (Spain); Allergy Service, IBIMA-Regional University Hospital of Malaga, UMA, Málaga (Spain)

    2015-11-01

    The mechanisms leading to drug allergy in predisposed patients, especially those related to T-cell-mediated drug hypersensitivity, are not well understood. A key event in allergic reactions to drugs is the maturation process undergone by dendritic cells (DCs). Although amoxicillin (AX) has been reported to interact and maturate DCs from patients with AX-induced delayed-type hypersensitivity, the cell signaling pathways related to AX-mediated DC maturation have not been elucidated. We sought to determine the role of the MAPK and NF-κΒ pathways on AX-induced DC maturation and functional status. For that purpose, in monocyte-derived-DCs from AX-delayed allergic patients and tolerant subjects, we analyzed the activation pattern of p38MAPK, JNK, and ERK signaling and the NF-κB, maturation markers as well as endocytosis and allostimulatory capacities driven by AX-stimulated-DCs. Our data reveal that AX induces an increase in the phosphorylation levels of the three MAPKsand activated NF-κB in DCs from allergic patients. Moreover, the inhibition of these pathways prevents the up-regulation of surface molecules induced by AX. Additionally, we observed that the allostimulatory capacity and the endocytosis down-regulation in AX-stimulated-DCs from allergic patients depend on JNK and NF-κB activities. Taken together, our data shed light for the first time on the main signaling pathways involved in DC maturation from AX-delayed allergic patient. - Highlights: • The cell signaling pathways related to drug-mediated DC maturation were tested. • Amoxicillin induces activation of MAPK and NF-κB in DCs from allergic patients. • The inhibition of these pathways prevents the up-regulation of DC surface molecules. • Their allostimulatory and endocytosis capacities depend on JNK and NF-κB activities. • The low involvement of p38-MAPK could be the cause of an incomplete DC maturation.

  8. Immunoregulatory effects of human dental pulp-derived stem cells on T cells: comparison of transwell co-culture and mixed lymphocyte reaction systems.

    Science.gov (United States)

    Demircan, Pinar Cetinalp; Sariboyaci, Ayla Eker; Unal, Zehra Seda; Gacar, Gulcin; Subasi, Cansu; Karaoz, Erdal

    2011-11-01

    BACKGROUND AIMS. Studies performed using human and animal models have indicated the immunoregulatory capability of mesenchymal stromal cells in several lineages. We investigated whether human dental pulp-derived stem cells (hDP-SC) have regulatory effects on phytohemagglutinin (PHA)-activated CD3(+) T cells. We aimed to define the regulatory mechanisms associated with hDP-SC that occur in mixed lymphocyte reaction (MLR) and transwell systems with PHA-CD3(+) T cells and hDP-SC at a ratio of 1:1. METHODS. Proliferation, apoptosis and pro- and anti-inflammatory cytokines of PHA-CD3(+)T cells, the expression of Regulatory T cells (Treg) markers and some regulatory factors related to hDP-SC, were studied in Both transwell and MLR are co-cultures systems. RESULTS. Anti-proliferative and apoptotic effects of hDP-SC were determined in co-culture systems. Elevated expression levels of human leukocyte antigen (HLA)-G, hepatocyte growth factor (HGF)-β1, intracellular adhesion molecule (ICAM-1)-1, interleukin (IL)-6, IL-10, transforming growth factor (TGF)-β1, vascular adhesion molecule (VCAM)-1 and vascular endothelial growth factor (VEGF) by hDP-SC were detected in the co-culture systems. We observed decreased expression levels of pro-inflammatory cytokines [interferon (IFN)-γ, IL-2, IL-6 receptor (R), IL-12, Interleukin-17A (IL-17A), tumor necrosis factor (TNF)-α] and increased expression levels of anti-inflammatory cytokine [inducible protein (IP)-10] from PHA-CD3(+) T cells in the transwell system. Expression of Treg (CD4(+) CD25(+) Foxp3(+)) markers was significantly induced by hDP-SC in both co-culture systems. We observed apoptosis of PHA-CD3(+) T cells with 24 h using time-lapse camera photographs and active caspase labeling; it is likely that paracrine soluble factors and molecular signals secreted by hDP-SC led this apoptosis. CONCLUSIONS. We suggest that hDP-SC have potent immunoregulatory functions because of their soluble factors and cytokines via paracrine

  9. A critical review of cell culture strategies for modelling intracortical brain implant material reactions.

    Science.gov (United States)

    Gilmour, A D; Woolley, A J; Poole-Warren, L A; Thomson, C E; Green, R A

    2016-06-01

    The capacity to predict in vivo responses to medical devices in humans currently relies greatly on implantation in animal models. Researchers have been striving to develop in vitro techniques that can overcome the limitations associated with in vivo approaches. This review focuses on a critical analysis of the major in vitro strategies being utilized in laboratories around the world to improve understanding of the biological performance of intracortical, brain-implanted microdevices. Of particular interest to the current review are in vitro models for studying cell responses to penetrating intracortical devices and their materials, such as electrode arrays used for brain computer interface (BCI) and deep brain stimulation electrode probes implanted through the cortex. A background on the neural interface challenge is presented, followed by discussion of relevant in vitro culture strategies and their advantages and disadvantages. Future development of 2D culture models that exhibit developmental changes capable of mimicking normal, postnatal development will form the basis for more complex accurate predictive models in the future. Although not within the scope of this review, innovations in 3D scaffold technologies and microfluidic constructs will further improve the utility of in vitro approaches. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Anti-HI can cause a severe delayed hemolytic transfusion reaction with hyperhemolysis in sickle cell disease patients.

    Science.gov (United States)

    Ibanez, Clara; Habibi, Anoosha; Mekontso-Dessap, Armand; Chadebech, Philippe; Chami, Btissam; Bierling, Philippe; Galactéros, Frédéric; Rieux, Claire; Nataf, Joëlle; Bartolucci, Pablo; Peyrard, Thierry; Pirenne, France

    2016-07-01

    Delayed hemolytic transfusion reaction (DHTR) is a life-threatening condition in sickle cell disease (SCD) patients that is frequently complicated by hyperhemolysis. Antibodies resulting from antigen disparity between donors of European ancestry and patients of African ancestry are common, but situations involving antibodies not classically of clinical significance are also encountered. Anti-HI is generally considered to be an innocuous naturally occurring antibody. We describe two cases of hyperhemolysis with anti-HI and provide details of the reported cases. Both SCD patients were polyimmunized and belonged to blood group B. They developed anti-HI that was reactive at 37°C, after the transfusion of group O red blood cell units matched for all known and produced antibodies classically considered to be clinically significant. Both patients developed DHTR with hyperhemolysis. In the first case, a pregnant woman, a second transfusion was unavoidable and the patient died from cardiac arrest. The state of the second patient improved without the need for further transfusion. Three other cases of DHTR with anti-HI have been described in the literature in SCD patients. The two additional cases reported here definitively demonstrate that anti-HI is dangerous in SCD patients. As a result, ABO-identical matching (including A1 status) must be considered in SCD patients with anti-HI. © 2016 AABB.

  11. Investigation of a Pt-Fe/C catalyst for oxygen reduction reaction in direct ethanol fuel cells

    International Nuclear Information System (INIS)

    Castro Luna, A. M.; Bonesi, A.; Triaca, W. E.; Blasi, A. Di; Stassi, A.; Baglio, V.; Antonucci, V.; Arico, A. S.

    2010-01-01

    Three cathode catalysts (60% Pt/C, 30% Pt/C and 60% Pt-Fe/C), with a particle size of about 2-3 nm, were prepared to investigate the effect of ethanol cross-over on cathode surfaces. All samples were studied in terms of structure and morphology by using X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses. Their electrocatalytic behavior in terms of oxygen reduction reaction (ORR) was investigated and compared using a rotating disk electrode (RDE). The tolerance of cathode catalysts in the presence of ethanol was evaluated. The Pt-Fe/C catalyst showed both higher ORR activity and tolerance to ethanol cross-over than Pt/C catalysts. Moreover, the more promising catalysts were tested in 5 cm 2 DEFC single cells at 60 and 80 o C. An improvement in single cell performance was observed in the presence of the Pt-Fe catalyst, due to an enhancement in the oxygen reduction kinetics. The maximum power density was 53 mW cm -2 at 2 bar rel. cathode pressure and 80 o C.

  12. Capillary zone electrophoresis-multiple reaction monitoring from 100 pg of RAW 264.7 cell lysate digest.

    Science.gov (United States)

    Sun, Liangliang; Li, Yihan; Champion, Matthew M; Zhu, Guijie; Wojcik, Roza; Dovichi, Norman J

    2013-06-07

    Capillary zone electrophoresis-multiple/single reaction monitoring (CZE-MRM/SRM), which employed an electrokinetically driven sheath-flow electrospray interface, was used for the rapid and highly sensitive detection of protein analytes in complex tryptic digests. MRM channels were developed against a commercial exponential mixture of bovine proteins. Five proteins spanning four orders of magnitude concentration range were confidently detected from only 2.5 ng of the digest mixture; the mass detection limits (S/N = 3) of two detected proteins, alpha-casein and glutamate dehydrogenase were about 600 zmol and 30 amol, respectively. This technique was then applied to a RAW 264.7 cell lysate digest. Three proteins were confidently and reproducibly detected from 100 pg of this digest. The sample amount corresponds to the approximate protein content from a single cell, which suggests that CZE-MRM may be a useful analytical tool in chemical cytometry. In addition to providing highly sensitive detection of proteins in complex mixtures, this system is highly rapid; migration time of the protein digests was less than 10 min.

  13. Radiation enteropathy and leucocyte-endothelial cell reactions in a refined small bowel model

    Directory of Open Access Journals (Sweden)

    Osman Nadia

    2004-09-01

    Full Text Available Abstract Background Leucocyte recruitment and inflammation are key features of high dose radiation-induced tissue injury. The inflammatory response in the gut may be more pronounced following radiotherapy due to its high bacterial load in comparison to the response in other organs. We designed a model to enable us to study the effects of radiation on leucocyte-endothelium interactions and on intestinal microflora in the murine ileum. This model enables us to study specifically the local effects of radiation therapy. Method A midline laparotomy was performed in male C57/Bl6 mice and a five-centimetre segment of ileum is irradiated using the chamber. Leucocyte responses (rolling and adhesion were then analysed in ileal venules 2 – 48 hours after high dose irradiation, made possible by an inverted approach using intravital fluorescence microscopy. Furthermore, intestinal microflora, myeloperoxidase (MPO and cell histology were analysed. Results The highest and most reproducible increase in leucocyte rolling was exhibited 2 hours after high dose irradiation whereas leucocyte adhesion was greatest after 16 hours. Radiation reduced the intestinal microflora count compared to sham animals with a significant decrease in the aerobic count after 2 hours of radiation. Further, the total aerobic counts, Enterobacteriaceae and Lactobacillus decreased significantly after 16 hours. In the radiation groups, the bacterial count showed a progressive increase from 2 to 24 hours after radiation. Conclusion This study presents a refinement of a previous method of examining mechanisms of radiation enteropathy, and a new approach at investigating radiation induced leucocyte responses in the ileal microcirculation. Radiation induced maximum leucocyte rolling at 2 hours and adhesion peaked at 16 hours. It also reduces the microflora count, which then starts to increase steadily afterwards. This model may be instrumental in developing strategies against pathological

  14. Acyl chains of phospholipase D transphosphatidylation products in Arabidopsis cells: a study using multiple reaction monitoring mass spectrometry.

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    Dominique Rainteau

    Full Text Available BACKGROUND: Phospholipases D (PLD are major components of signalling pathways in plant responses to some stresses and hormones. The product of PLD activity is phosphatidic acid (PA. PAs with different acyl chains do not have the same protein targets, so to understand the signalling role of PLD it is essential to analyze the composition of its PA products in the presence and absence of an elicitor. METHODOLOGY/PRINCIPAL FINDINGS: Potential PLD substrates and products were studied in Arabidopsis thaliana suspension cells treated with or without the hormone salicylic acid (SA. As PA can be produced by enzymes other than PLD, we analyzed phosphatidylbutanol (PBut, which is specifically produced by PLD in the presence of n-butanol. The acyl chain compositions of PBut and the major glycerophospholipids were determined by multiple reaction monitoring (MRM mass spectrometry. PBut profiles of untreated cells or cells treated with SA show an over-representation of 160/18:2- and 16:0/18:3-species compared to those of phosphatidylcholine and phosphatidylethanolamine either from bulk lipid extracts or from purified membrane fractions. When microsomal PLDs were used in in vitro assays, the resulting PBut profile matched exactly that of the substrate provided. Therefore there is a mismatch between the acyl chain compositions of putative substrates and the in vivo products of PLDs that is unlikely to reflect any selectivity of PLDs for the acyl chains of substrates. CONCLUSIONS: MRM mass spectrometry is a reliable technique to analyze PLD products. Our results suggest that PLD action in response to SA is not due to the production of a stress-specific molecular species, but that the level of PLD products per se is important. The over-representation of 160/18:2- and 16:0/18:3-species in PLD products when compared to putative substrates might be related to a regulatory role of the heterogeneous distribution of glycerophospholipids in membrane sub-domains.

  15. Factors associated with acute oral mucosal reaction induced by radiotherapy in head and neck squamous cell carcinoma: A retrospective single-center experience.

    Science.gov (United States)

    Tao, Zhenchao; Gao, Jin; Qian, Liting; Huang, Yifan; Zhou, Yan; Yang, Liping; He, Jian; Yang, Jing; Wang, Ru; Zhang, Yangyang

    2017-12-01

    To investigate risk factors for acute oral mucosal reaction during head and neck squamous cell carcinoma radiotherapy.A retrospective study of patients with head and neck squamous cell carcinoma who underwent radiotherapy from November 2013 to May 2016 in Anhui Provincial Cancer Hospital was conducted. Data on the occurrence and severity of acute oral mucositis were extracted from clinical records. Based on the Radiation Therapy Oncology Group (RTOG) grading of acute radiation mucosal injury, the patients were assigned into acute reaction (grades 2-4) and minimum reaction (grades 0-1) groups. Preradiotherapy characteristics and treatment factors were compared between the 2 groups. Multivariate logistic regression analysis was used to detect the independent factors associated with acute oral mucosal reactions.Eighty patients completed radiotherapy during the study period. Oral mucosal reactions were recorded as 25, 31, and 24 cases of grades 1, 2, and 3 injuries, respectively. Significant differences between acute reaction and minimum reaction groups were detected in cancer lymph node (N) staging, smoking and diabetes history, pretreatment platelet count and T-Helper/T-Suppressor lymphocyte (Th/Ts) ratio, concurrent chemotherapy, and total and single irradiation doses.Multivariate analysis showed that N stage, smoking history, single dose parapharyngeal irradiation, and pretreatment platelet count were independent risk factors for acute radiation induced oral mucosal reaction. Smoking history, higher grading of N stage, higher single dose irradiation, and lower preirradiation platelet count may increase the risk and severity of acute radiation oral mucosal reaction in radiotherapy of head and neck cancer patients. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

  16. Distinct Roles of Th17 and Th1 Cells in Inflammatory Responses Associated with the Presentation of Paucibacillary Leprosy and Leprosy Reactions.

    Science.gov (United States)

    Santos, M B; de Oliveira, D T; Cazzaniga, R A; Varjão, C S; Dos Santos, P L; Santos, M L B; Correia, C B; Faria, D R; Simon, M do V; Silva, J S; Dutra, W O; Reed, S G; Duthie, M S; de Almeida, R P; de Jesus, A R

    2017-07-01

    It is well established that helper T cell responses influence resistance or susceptibility to Mycobacterium leprae infection, but the role of more recently described helper T cell subsets in determining severity is less clear. To investigate the involvement of Th17 cells in the pathogenesis of leprosy, we determined the immune profile with variant presentations of leprosy. Firstly, IL-17A, IFN-γ and IL-10 were evaluated in conjunction with CD4 + T cell staining by confocal microscopy of lesion biopsies from tuberculoid (TT) and lepromatous leprosy (LL) patients. Secondly, inflammatory cytokines were measured by multiplex assay of serum samples from Multibacillary (MB, n = 28) and Paucibacillary (PB, n = 23) patients and household contacts (HHC, n = 23). Patients with leprosy were also evaluated for leprosy reaction occurrence: LR+ (n = 8) and LR- (n = 20). Finally, peripheral blood mononuclear cells were analysed by flow cytometry used to determine the phenotype of cytokine-producing cells. Lesions from TT patients were found to have more CD4 + IL-17A + cells than those from LL patients. Higher concentrations of IL-17A and IL-1β were observed in serum from PB than MB patients. The highest serum IFN-γ concentrations were, however, detected in sera from MB patients that developed leprosy reactions (MB LR + ). Together, these results indicate that Th1 cells were associated with both the PB presentation and also with leprosy reactions. In contrast, Th17 cells were associated with an effective inflammatory response that is present in the PB forms but were not predictive of leprosy reactions in MB patients. © 2017 The Foundation for the Scandinavian Journal of Immunology.

  17. In situ observation of the reaction of tantalum with nitrogen in a laser heated diamond anvil cell

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, Alexandra, E-mail: friedrich@kristall.uni-frankfurt.d [Institut fuer Geowissenschaften, Goethe-Universitaet Frankfurt, Altenhoeferallee 1, D-60438 Frankfurt am Main (Germany); Winkler, Bjoern; Bayarjargal, Lkhamsuren [Institut fuer Geowissenschaften, Goethe-Universitaet Frankfurt, Altenhoeferallee 1, D-60438 Frankfurt am Main (Germany); Juarez Arellano, Erick A. [Universidad del Papaloapan, Circuito Central 200, Parque Industrial, Tuxtepec 68301 (Mexico); Morgenroth, Wolfgang; Biehler, Jasmin; Schroeder, Florian [Institut fuer Geowissenschaften, Goethe-Universitaet Frankfurt, Altenhoeferallee 1, D-60438 Frankfurt am Main (Germany); Yan, Jinyuan; Clark, Simon M. [Advanced Light Source, Lawrence Berkeley National Laboratory, MS6R2100, 1 Cyclotron Road, Berkeley, CA 94720-8226 (United States)

    2010-07-16

    Tantalum nitrides were formed by reaction of the elements at pressures between 9(1) and 12.7(5) GPa and temperatures >1600-2000 K in the laser-heated diamond anvil cell. The incorporation of small amount of nitrogen in the tantalum structure was identified as the first reaction product on weak laser irradiation. Subsequent laser heating led to the formation of hexagonal {beta}-Ta{sub 2}N and orthorhombic {eta}-Ta{sub 2}N{sub 3}, which was the stable phase at pressures up to 27 GPa and high temperatures. No evidence was found for the presence of {epsilon}-TaN, {theta}-TaN, {delta}-TaN, Ta{sub 3}N{sub 5}-I or Ta{sub 3}N{sub 5}-II, which was predicted to be the stable phase at P>17 GPa and T=2800 K, at the P,T-conditions of this experiment. The bulk modulus of {eta}-Ta{sub 2}N{sub 3} was determined to be B{sub 0}=319(6) GPa from a 2nd order Birch-Murnaghan equation of state fit to the experimental data, while quantum mechanical calculations using the density functional theory gave a bulk modulus of B{sub 0}=348.0(9) GPa for a 2nd-order fit or B{sub 0}=339(1) GPa and B{sup '}=4.67(9) for a 3rd-order fit. The values show the large incompressibility of this high-pressure phase. From the DFT data the structural compression mechanism could be determined.

  18. Electrochemical Deposition of Platinum and Palladium on Gold Nanoparticles Loaded Carbon Nanotube Support for Oxidation Reactions in Fuel Cell

    Directory of Open Access Journals (Sweden)

    Surin Saipanya

    2014-01-01

    Full Text Available Pt and Pd sequentially electrodeposited Au nanoparticles loaded carbon nanotube (Au-CNT was prepared for the electrocatalytic study of methanol, ethanol, and formic acid oxidations. All electrochemical measurements were carried out in a three-electrode cell. A platinum wire and Ag/AgCl were used as auxiliary and reference electrodes, respectively. Suspension of the Au-CNT, phosphate buffer, isopropanol, and Nafion was mixed and dropped on glassy carbon as a working electrode. By sequential deposition method, PdPtPt/Au-CNT, PtPdPd/Au-CNT, and PtPdPt/Au-CNT catalysts were prepared. Cyclic voltammograms (CVs of those catalysts in 1 M H2SO4 solution showed hydrogen adsorption and hydrogen desorption reactions. CV responses for those three catalysts in methanol, ethanol, and formic acid electrooxidations studied in 2 M CH3OH, CH3CH2OH, and HCOOH in 1 M H2SO4 show characteristic oxidation peaks. The oxidation peaks at anodic scan contribute to those organic substance oxidations while the peaks at cathodic scan are related with the reoxidation of the adsorbed carbonaceous species. Comparing all those three catalysts, it can be found that the PdPtPt/Au-CNT catalyst is good at methanol oxidation; the PtPdPt/Au-CNT effectively enhances ethanol oxidation while the PtPdPd/Au-CNT exceptionally catalyzes formic acid oxidation. Therefore, a different stoichiometry affects the electrochemical active surface area of the catalysts to achieve the catalytic oxidation reactions.

  19. The start-up phase of the national satellite forest monitoring systems for DRC and PNG: a joint venture between FAO and INPE

    Science.gov (United States)

    Jonckheere, I. G.; FAO UN-REDD Team Forestry Department

    2011-12-01

    Reducing Emissions from Deforestation and Forest Degradation (REDD) is an effort to create a financial value for the carbon stored in forests, offering incentives for developing countries to reduce emissions from forested lands and invest in low-carbon paths to sustainable development. "REDD+" goes beyond deforestation and forest degradation, and includes the role of conservation, sustainable management of forests and enhancement of forest carbon stocks. In the framework of getting countries ready for REDD+, the UN-REDD Programme, a partnership between UNEP, FAO and UNDP, assists developing countries to prepare and implement national REDD+ strategies. Designed collaboratively by a broad range of stakeholders, national UN-REDD Programmes are informed by the technical expertise of FAO, UNDP and UNEP. For the monitoring, reporting and verification, FAO supports the countries to develop satellite forest monitoring systems that allow for credible measurement, reporting and verification (MRV)of REDD+ activities. These are among the most critical elements for the successful implementation of any REDD+ mechanism, also following the COP 16 decisions in Cancun last year. The UN-REDD Programme through a joint effort of FAO and Brazil's National Space Agency, INPE, is supporting countries to develop cost-effective, robust and compatible national monitoring and MRV systems, providing tools, methodologies, training and knowledge sharing that help countries to strengthen their technical and institutional capacity for effective MRV systems. To develop strong nationally-owned forest monitoring systems, technical and institutional capacity building is key. The UN-REDD Programme, through FAO, has taken on intensive training together with INPE, and has provided technical help and assistance for in-country training and implementation for national satellite forest monitoring. The goal of the start-up phase for DRC and Papua New Guinea (PNG) in this capacity building effort is the

  20. The effect of a crosslinking chemical reaction on pattern formation in viscous fingering of miscible fluids in a Hele-Shaw cell

    Science.gov (United States)

    Bunton, Patrick H.; Tullier, Michael P.; Meiburg, Eckart; Pojman, John A.

    2017-10-01

    Viscous fingering can occur in fluid motion whenever a high mobility fluid displaces a low mobility fluid in a Darcy type flow. When the mobility difference is primarily attributable to viscosity (e.g., flow between the two horizontal plates of a Hele-Shaw cell), viscous fingering (VF) occurs, which is sometimes termed the Saffman-Taylor instability. Alternatively, in the presence of differences in density in a gravity field, buoyancy-driven convection can occur. These instabilities have been studied for decades, in part because of their many applications in pollutant dispersal, ocean currents, enhanced petroleum recovery, and so on. More recent interest has emerged regarding the effects of chemical reactions on fingering instabilities. As chemical reactions change the key flow parameters (densities, viscosities, and concentrations), they may have either a destabilizing or stabilizing effect on the flow. Hence, new flow patterns can emerge; moreover, one can then hope to gain some control over flow instabilities through reaction rates, flow rates, and reaction products. We report effects of chemical reactions on VF in a Hele-Shaw cell for a reactive step-growth cross-linking polymerization system. The cross-linked reaction product results in a non-monotonic viscosity profile at the interface, which affects flow stability. Furthermore, three-dimensional internal flows influence the long-term pattern that results.

  1. Modelling strategic interventions in a population with a total fertility rate of 8.3: a cross-sectional study of Idjwi Island, DRC

    Directory of Open Access Journals (Sweden)

    Thomson Dana R

    2012-11-01

    Full Text Available Abstract Background Idjwi, an island of approximately 220,000 people, is located in eastern DRC and functions semi-autonomously under the governance of two kings (mwamis. At more than 8 live births per woman, Idjwi has one of the highest total fertility rates (TFRs in the world. Rapid population growth has led to widespread environmental degradation and food insecurity. Meanwhile family planning services are largely unavailable. Methods At the invitation of local leaders, we conducted a representative survey of 2,078 households in accordance with MEASURE DHS protocols, and performed ethnographic interviews and focus groups with key informants and vulnerable subpopulations. Modelling proximate determinates of fertility, we evaluated how the introduction of contraceptives and/or extended periods of breastfeeding could reduce the TFR. Results Over half of all women reported an unmet need for spacing or limiting births, and nearly 70% named a specific modern method of contraception they would prefer to use; pills (25.4% and injectables (26.5% were most desired. We predicted that an increased length of breastfeeding (from 10 to 21 months or an increase in contraceptive prevalence (from 1% to 30%, or a combination of both could reduce TFR on Idjwi to 6, the average desired number of children. Increasing contraceptive prevalence to 15% could reduce unmet need for contraception by 8%. Conclusions To meet women’s need and desire for fertility control, we recommend adding family planning services at health centers with NGO support, pursuing a community health worker program, promoting extended breastfeeding, and implementing programs to end sexual- and gender-based violence toward women.

  2. Learning lessons from field surveys in humanitarian contexts: a case study of field surveys conducted in North Kivu, DRC 2006-2008

    Directory of Open Access Journals (Sweden)

    Grellety Emmanuel

    2009-09-01

    Full Text Available Abstract Survey estimates of mortality and malnutrition are commonly used to guide humanitarian decision-making. Currently, different methods of conducting field surveys are the subject of debate among epidemiologists. Beyond the technical arguments, decision makers may find it difficult to conceptualize what the estimates actually mean. For instance, what makes this particular situation an emergency? And how should the operational response be adapted accordingly. This brings into question not only the quality of the survey methodology, but also the difficulties epidemiologists face in interpreting results and selecting the most important information to guide operations. As a case study, we reviewed mortality and nutritional surveys conducted in North Kivu, Democratic Republic of Congo (DRC published from January 2006 to January 2009. We performed a PubMed/Medline search for published articles and scanned publicly available humanitarian databases and clearinghouses for grey literature. To evaluate the surveys, we developed minimum reporting criteria based on available guidelines and selected peer-review articles. We identified 38 reports through our search strategy; three surveys met our inclusion criteria. The surveys varied in methodological quality. Reporting against minimum criteria was generally good, but presentation of ethical procedures, raw data and survey limitations were missed in all surveys. All surveys also failed to consider contextual factors important for data interpretation. From this review, we conclude that mechanisms to ensure sound survey design and conduct must be implemented by operational organisations to improve data quality and reporting. Training in data interpretation would also be useful. Novel survey methods should be trialled and prospective data gathering (surveillance employed wherever feasible.

  3. Redox reactions of the α-synuclein-Cu(2+) complex and their effects on neuronal cell viability.

    Science.gov (United States)

    Wang, Chengshan; Liu, Lin; Zhang, Lin; Peng, Yong; Zhou, Feimeng

    2010-09-21

    α-Synuclein (α-syn), a presynaptic protein believed to play an important role in neuropathology in Parkinson's disease (PD), is known to bind Cu(2+). Cu(2+) has been shown to accelerate the aggregation of α-syn to form various toxic aggregates in vitro. Copper is also a redox-active metal whose complexes with amyloidogenic proteins/peptides have been linked to oxidative stress in major neurodegenerative diseases. In this work, the formation of the Cu(2+) complex with α-syn or with an N-terminal peptide, α-syn(1-19), was confirmed with electrospray-mass spectrometry (ES-MS). The redox potentials of the Cu(2+) complex with α-syn (α-syn-Cu(2+)) and α-syn(1-19) were determined to be 0.018 and 0.053 V, respectively. Furthermore, the Cu(2+) center(s) can be readily reduced to Cu(+), and possible reactions of α-syn-Cu(2+) with cellular species (e.g., O(2), ascorbic acid, and dopamine) were investigated. The occurrence of a redox reaction can be rationalized by comparing the redox potential of the α-syn-Cu(2+) complex to that of the specific cellular species. For example, ascorbic acid can directly reduce α-syn-Cu(2+) to α-syn-Cu(+), setting up a redox cycle in which O(2) is reduced to H(2)O(2) and cellular redox species is continuously exhausted. In addition, the H(2)O(2) generated was demonstrated to reduce viability of the neuroblastoma SY-HY5Y cells. Although our results ruled out the direct oxidation of dopamine by α-syn-Cu(2+), the H(2)O(2) generated in the presence of α-syn-Cu(2+) can oxidize dopamine. Our results suggest that oxidative stress is at least partially responsible for the loss of dopaminergic cells in PD brain and reveal the multifaceted role of the α-syn-Cu(2+) complex in oxidative stress associated with PD symptoms.

  4. Rice hypersensitive induced reaction protein 1 (OsHIR1) associates with plasma membrane and triggers hypersensitive cell death.

    Science.gov (United States)

    Zhou, Liang; Cheung, Ming-Yan; Li, Man-Wah; Fu, Yaping; Sun, Zongxiu; Sun, Sai-Ming; Lam, Hon-Ming

    2010-12-30

    In plants, HIR (Hypersensitive Induced Reaction) proteins, members of the PID (Proliferation, Ion and Death) superfamily, have been shown to play a part in the development of spontaneous hypersensitive response lesions in leaves, in reaction to pathogen attacks. The levels of HIR proteins were shown to correlate with localized host cell deaths and defense responses in maize and barley. However, not much was known about the HIR proteins in rice. Since rice is an important cereal crop consumed by more than 50% of the populations in Asia and Africa, it is crucial to understand the mechanisms of disease responses in this plant. We previously identified the rice HIR1 (OsHIR1) as an interacting partner of the OsLRR1 (rice Leucine-Rich Repeat protein 1). Here we show that OsHIR1 triggers hypersensitive cell death and its localization to the plasma membrane is enhanced by OsLRR1. Through electron microscopy studies using wild type rice plants, OsHIR1 was found to mainly localize to the plasma membrane, with a minor portion localized to the tonoplast. Moreover, the plasma membrane localization of OsHIR1 was enhanced in transgenic rice plants overexpressing its interacting protein partner, OsLRR1. Co-localization of OsHIR1 and OsLRR1 to the plasma membrane was confirmed by double-labeling electron microscopy. Pathogen inoculation studies using transgenic Arabidopsis thaliana expressing either OsHIR1 or OsLRR1 showed that both transgenic lines exhibited increased resistance toward the bacterial pathogen Pseudomonas syringae pv. tomato DC3000. However, OsHIR1 transgenic plants produced more extensive spontaneous hypersensitive response lesions and contained lower titers of the invading pathogen, when compared to OsLRR1 transgenic plants. The OsHIR1 protein is mainly localized to the plasma membrane, and its subcellular localization in that compartment is enhanced by OsLRR1. The expression of OsHIR1 may sensitize the plant so that it is more prone to HR and hence can react more

  5. Expression of CD73 slows down migration of skin dendritic cells, affecting the sensitization phase of contact hypersensitivity reactions in mice.

    Science.gov (United States)

    Neuberger, A; Ring, S; Silva-Vilches, C; Schrader, J; Enk, A; Mahnke, K

    2017-09-01

    Application of haptens to the skin induces release of immune stimulatory ATP into the extracellular space. This "danger" signal can be converted to immunosuppressive adenosine (ADO) by the action of the ectonucleotidases CD39 and CD73, expressed by skin and immune cells. Thus, the expression and regulation of CD73 by skin derived cells may have crucial influence on the outcome of contact hypersensitivity (CHS) reactions. To investigate the role of CD73 expression during 2,4,6-trinitrochlorobenzene (TNCB) induced CHS reactions. Wild type (wt) and CD73 deficient mice were subjected to TNCB induced CHS. In the different mouse strains the resulting ear swelling reaction was recorded along with a detailed phenotypic analysis of the skin migrating subsets of dendritic cells (DC). In CD73 deficient animals the motility of DC was higher as compared to wt animals and in particular after sensitization we found increased migration of Langerin + DC from skin to draining lymph nodes (LN). In the TNCB model this led to a stronger sensitization as indicated by increased frequency of interferon-γ producing T cells in the LN and an increased ear thickness after challenge. CD73 derived ADO production slows down migration of Langerin + DC from skin to LN. This may be a crucial mechanism to avoid over boarding immune reactions against haptens. Copyright © 2017 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

  6. Iridium-decorated palladium-platinum core-shell catalysts for oxygen reduction reaction in proton exchange membrane fuel cell.

    Science.gov (United States)

    Wang, Chen-Hao; Hsu, Hsin-Cheng; Wang, Kai-Ching

    2014-08-01

    Carbon-supported Pt, Pd, Pd-Pt core-shell (Pt(shell)-Pd(core)/C) and Ir-decorated Pd-Pt core-shell (Ir-decorated Pt(shell)-Pd(core)/C) catalysts were synthesized, and their physical properties, electrochemical behaviors, oxygen reduction reaction (ORR) characteristics and proton exchange membrane fuel cell (PEMFC) performances were investigated herein. From the XRD patterns and TEM images, Ir-decorated Pt(shell)-Pd(core)/C has been confirmed that Pt was deposited on the Pd nanoparticle which had the core-shell structure. Ir-decorated Pt(shell)-Pd(core)/C has more positive OH reduction peak than Pt/C, which is beneficial to weaken the binding energy of Pt-OH during the ORR. Thus, Ir-decorated Pt(shell)-Pd(core)/C has higher ORR activity than Pt/C. The maximum power density of H2-O2 PEMFC using Ir-decorated Pt(shell)-Pd(core)/C is 792.2 mW cm(-2) at 70°C, which is 24% higher than that using Pt/C. The single-cell accelerated degradation test of PEMFC using Ir-decorated Pt(shell)-Pd(core)/C shows good durability by the potential cycling of 40,000 cycles. This study concludes that Ir-decorated Pt(shell)-Pd(core)/C has the low Pt content, but it can facilitate the low-cost and high-efficient PEMFC. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Effects of grain boundaries at the electrolyte/cathode interfaces on oxygen reduction reaction kinetics of solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Min Gi; Koo, Ja Yang; Ahn, Min Woo; Lee, Won Young [Dept. of Mechanical Engineering, Sungkyunkwan University, Suwon (Korea, Republic of)

    2017-04-15

    We systematically investigated the effects of grain boundaries (GBs) at the electrolyte/cathode interface of two conventional electrolyte materials, i.e., yttria-stabilized zirconia (YSZ) and gadolinia-doped ceria (GDC). We deposited additional layers by pulsed laser deposition to control the GB density on top of the polycrystalline substrates, obtaining significant improvements in peak power density (two-fold for YSZ and three-fold for GDC). The enhanced performance at high GB density in the additional layer could be ascribed to the accumulation of oxygen vacancies, which are known to be more active sites for oxygen reduction reactions (ORR) than grain cores. GDC exhibited a higher enhancement than YSZ, due to the easier formation, and thus higher concentration, of oxygen vacancies for ORR. The strong relation between the concentration of oxygen vacancies and the surface exchange characteristics substantiated the role of GBs at electrolyte/cathode interfaces on ORR kinetics, providing new design parameters for highly performing solid oxide fuel cells.

  8. Novel RuCoSe as non-platinum catalysts for oxygen reduction reaction in microbial fuel cells

    Science.gov (United States)

    Rozenfeld, Shmuel; Schechter, Michal; Teller, Hanan; Cahan, Rivka; Schechter, Alex

    2017-09-01

    Microbial electrochemical cells (MECs) are explored for the conversion of acetate directly to electrical energy. This device utilizes a Geobacter sulfurreducens anode and a novel RuCoSe air cathode. RuCoSe synthesized in selected compositions by a borohydride reduction method produces amorphous structures of powdered agglomerates. Oxygen reduction reaction (ORR) was measured in a phosphate buffer solution pH 7 using a rotating disc electrode (RDE), from which the kinetic current (ik) was measured as a function of potential and composition. The results show that ik of RuxCoySe catalysts increases in the range of XRu = 0.25 > x > 0.7 and y < 0.15 for all tested potentials. A poisoning study of RuCoSe and Pt catalysts in a high concentration acetate solution shows improved tolerance of RuCoSe to this fuel at acetate concentration ≥500 mM. MEC discharge plots under physiological conditions show that ∼ RuCo2Se (sample S3) has a peak power density of 750 mW cm-2 which is comparable with Pt 900 mW cm-2.

  9. Polymersomes containing iron sulfide (FeS) as primordial cell model : for the investigation of energy providing redox reactions.

    Science.gov (United States)

    Alpermann, Theodor; Rüdel, Kristin; Rüger, Ronny; Steiniger, Frank; Nietzsche, Sandor; Filiz, Volkan; Förster, Stephan; Fahr, Alfred; Weigand, Wolfgang

    2011-04-01

    According to Wächtershäuser's "Iron-Sulfur-World" one major requirement for the development of life on the prebiotic Earth is compartmentalization. Vesicles spontaneously formed from amphiphilic components containing a specific set of molecules including sulfide minerals may have lead to the first autotrophic prebiotic units. The iron sulfide minerals may have been formed by geological conversions in the environment of deep-sea volcanos (black smokers), which can be observed even today. Wächtershäuser postulated the evolution of chemical pathways as fundamentals of the origin of life on earth. In contrast to the classical Miller-Urey experiment, depending on external energy sources, the "Iron-Sulfur-World" is based on the catalytic and energy reproducing redox system FeS+H2S-->FeS2+H2. The energy release out of this redox reaction (∆RG°=-38 kJ/mol, pH 0) could be the cause for the subsequent synthesis of complex organic molecules and the precondition for the development of more complex units similar to cells known today. Here we show the possibility for precipitating iron sulfide inside vesicles composed of amphiphilic block-copolymers as a model system for a first prebiotic unit. Our findings could be an indication for a chemoautotrophic FeS based origin of life.

  10. Submolecular regulation of cell transformation by deuterium depleting water exchange reactions in the tricarboxylic acid substrate cycle.

    Science.gov (United States)

    Boros, László G; D'Agostino, Dominic P; Katz, Howard E; Roth, Justine P; Meuillet, Emmanuelle J; Somlyai, Gábor

    2016-02-01

    The naturally occurring isotope of hydrogen ((1)H), deuterium ((2)H), could have an important biological role. Deuterium depleted water delays tumor progression in mice, dogs, cats and humans. Hydratase enzymes of the tricarboxylic acid (TCA) cycle control cell growth and deplete deuterium from redox cofactors, fatty acids and DNA, which undergo hydride ion and hydrogen atom transfer reactions. A model is proposed that emphasizes the terminal complex of mitochondrial electron transport chain reducing molecular oxygen to deuterium depleted water (DDW); this affects gluconeogenesis as well as fatty acid oxidation. In the former, the DDW is thought to diminish the deuteration of sugar-phosphates in the DNA backbone, helping to preserve stability of hydrogen bond networks, possibly protecting against aneuploidy and resisting strand breaks, occurring upon exposure to radiation and certain anticancer chemotherapeutics. DDW is proposed here to link cancer prevention and treatment using natural ketogenic diets, low deuterium drinking water, as well as DDW production as the mitochondrial downstream mechanism of targeted anti-cancer drugs such as Avastin and Glivec. The role of (2)H in biology is a potential missing link to the elusive cancer puzzle seemingly correlated with cancer epidemiology in western populations as a result of excessive (2)H loading from processed carbohydrate intake in place of natural fat consumption. Published by Elsevier Ltd.

  11. Removal of As, Mn, Mo, Se, U, V and Zn from groundwater by zero-valent iron in a passive treatment cell: reaction progress modeling

    Science.gov (United States)

    Morrison, Stan J.; Metzler, Donald R.; Dwyer, Brian P.

    2002-05-01

    Three treatment cells were operated at a site near Durango, CO. One treatment cell operated for more than 3 years. The treatment cells were used for passive removal of contamination from groundwater at a uranium mill tailings repository site. Zero-valent iron [Fe(0)] that had been powdered, bound with aluminosilicate and molded into plates was used as a reactive material in one treatment cell. The others used granular Fe(0) and steel wool. The treatment cells significantly reduced concentrations of As, Mn, Mo, Se, U, V and Zn in groundwater that flowed through it. Zero-valent iron [Fe(0)], magnetite (Fe 3O 4), calcite (CaCO 3), goethite (FeOOH) and mixtures of contaminant-bearing phases were identified in the solid fraction of one treatment cell. A reaction progress approach was used to model chemical evolution of water chemistry as it reacted with the Fe(0). Precipitation of calcite, ferrous hydroxide [Fe(OH) 2] and ferrous sulfide (FeS) were used to simulate observed changes in major-ion aqueous chemistry. The amount of reaction progress differed for each treatment cell. Changes in contaminant concentrations were consistent with precipitation of reduced oxides (UO 2, V 2O 3), sulfides (As 2S 3, ZnS), iron minerals (FeSe 2, FeMoO 4) and carbonate (MnCO 3). Formation of a free gas phase and precipitation of minerals contributed to loss of hydraulic conductivity in one treatment cell.

  12. Laser ablation inductively coupled plasma dynamic reaction cell mass spectrometry for the multi-element analysis of polymers

    Science.gov (United States)

    Resano, M.; García-Ruiz, E.; Vanhaecke, F.

    2005-11-01

    In this work, the potential of laser ablation-inductively coupled plasma-mass spectrometry for the fast analysis of polymers has been explored. Different real-life samples (polyethylene shopping bags, an acrylonitrile butadiene styrene material and various plastic bricks) as well as several reference materials (VDA 001 to 004, Cd in polyethylene) have been selected for the study. Two polyethylene reference materials (ERM-EC 680 and 681), for which a reference or indicative value for the most relevant metals is available, have proved their suitability as standards for calibration. Special attention has been paid to the difficulties expected for the determination of Cr at the μg g - 1 level in this kind of materials, due to the interference of ArC + ions on the most abundant isotopes of Cr. The use of ammonia as a reaction gas in a dynamic reaction cell is shown to alleviate this problem, resulting in a limit of detection of 0.15 μg g - 1 for this element, while limiting only modestly the possibilities of the technique for simultaneous multi-element analysis. In this regard, As is the analyte most seriously affected by the use of ammonia, and its determination has to be carried out in vented mode, at the expense of measuring time. In all cases studied, accurate results could be obtained for elements ranging in content from the sub-μg g - 1 level to tens of thousands of μg g - 1 . However, the use of an element of known concentration as internal standard may be needed for materials with a matrix significantly different from that of the standard (polyethylene in this work). Precision ranged between 5% and 10% RSD for elements found at the 10 μg g - 1 level or higher, while this value could deteriorate to 20% for analytes found at the sub-μg g - 1 level. Overall, the technique evaluated presents many advantages for the fast and accurate multi-element analysis of these materials, avoiding laborious digestion procedures and minimizing the risk of analyte losses due

  13. Limonin, a Component of Dictamni Radicis Cortex, Inhibits Eugenol-Induced Calcium and cAMP Levels and PKA/CREB Signaling Pathway in Non-Neuronal 3T3-L1 Cells

    Directory of Open Access Journals (Sweden)

    Yeo Cho Yoon

    2015-12-01

    Full Text Available Limonin, one of the major components in dictamni radicis cortex (DRC, has been shown to play various biological roles in cancer, inflammation, and obesity in many different cell types and tissues. Recently, the odorant-induced signal transduction pathway (OST has gained attention not only because of its function in the perception of smell but also because of its numerous physiological functions in non-neuronal cells. However, little is known about the effects of limonin and DRC on the OST pathway in non-neuronal cells. We investigated odorant-stimulated increases in Ca2+ and cAMP, major second messengers in the OST pathway, in non-neuronal 3T3-L1 cells pretreated with limonin and ethanol extracts of DRC. Limonin and the extracts significantly decreased eugenol-induced Ca2+ and cAMP levels and upregulated phosphorylation of CREB and PKA. Our results demonstrated that limonin and DRC extract inhibit the OST pathway in non-neuronal cells by modulating Ca2+ and cAMP levels and phosphorylation of CREB.

  14. Enhanced bimolecular exchange reaction through programmed coordination of a five-coordinate oxovanadium complex for efficient redox mediation in dye-sensitized solar cells.

    Science.gov (United States)

    Oyaizu, Kenichi; Hayo, Noriko; Sasada, Yoshito; Kato, Fumiaki; Nishide, Hiroyuki

    2013-12-07

    Electrochemical reversibility and fast bimolecular exchange reaction found for VO(salen) gave rise to a highly efficient redox mediation to enhance the photocurrent of a dye-sensitized solar cell, leading to an excellent photovoltaic performance with a conversion efficiency of 5.4%. A heterogeneous electron-transfer rate constant at an electrode (k0) and a second-order rate constant for an electron self-exchange reaction (k(ex)) were proposed as key parameters that dominate the charge transport property, which afforded a novel design concept for the mediators based on their kinetic aspects.

  15. "The co-authors of pregnancy": leveraging men's sense of responsibility and other factors for male involvement in antenatal services in Kinshasa, DRC.

    Science.gov (United States)

    Gill, Michelle M; Ditekemena, John; Loando, Aimé; Ilunga, Vicky; Temmerman, Marleen; Fwamba, Franck

    2017-12-06

    Despite efforts to improve male involvement (MI), few male partners typically attend antenatal care (ANC). MI in ANC and interventions to prevent mother-to-child HIV transmission have been demonstrated to be beneficial for the HIV-positive mother and her child. This study aimed to explore factors influencing partner attendance and highlight interventions with potential to improve MI within a Congolese context. This was an exploratory, qualitative study conducted in two urban and two semi-urban catchment areas of Kinshasa, DRC in June-September 2016. Two women-only and two men-only focus group discussions (FGDs) were held; participants were recruited from ANC clinics and surrounding communities. Key informants purposively selected from health facility leadership and central government were also interviewed. Guide topics included MI barriers and facilitators, experiences with couples' ANC attendance and perceptions of MI interventions and how to improve them. Data from FGDs and interviews were analyzed to determine three interventions that best addressed the identified MI facilitators and barriers. These interventions were explored further through dialogues held with representatives from community organizations. This study included 17 female and 18 male FGD participants, 3 key informants and 21 community dialogue participants. Receipt of clinic staff advice was the most commonly-reported factor facilitating male attendance. No time off work was the most commonly-reported barrier. Only men identified responsibility, referring to themselves as "authors of the pregnancy," and wanting to be tested for HIV as facilitators. The most promising interventions perceived by FGD and interview participants were male partner invitation letters, couple- and male-friendly improvements to ANC, and expert peer-to-peer outreach. Community dialogue participants provided further detail on these approaches, such as invitation letter content and counseling messages targeting men attending

  16. Pharmacokinetics and pharmacodynamics of artesunate and dihydroartemisinin following oral treatment in pregnant women with asymptomatic Plasmodium falciparum infections in Kinshasa DRC

    Directory of Open Access Journals (Sweden)

    Wesche David

    2011-02-01

    in the DRC. Although DHA AUC during pregnancy and postpartum were similar, the AUC for the pregnant group was less than the non-pregnant controls. The findings of this study suggest that additional studies on the pharmacokinetics of AS in pregnant women are needed. Trial Registration ClinicalTrials.gov: NCT00538382

  17. Lignin-derived electrospun carbon nanofiber mats with supercritically deposited Ag nanoparticles for oxygen reduction reaction in alkaline fuel cells

    International Nuclear Information System (INIS)

    Lai, Chuilin; Kolla, Praveen; Zhao, Yong; Fong, Hao; Smirnova, Alevtina L.

    2014-01-01

    Highlights: • Electrospun carbon nanofiber mats were prepared from a natural product of lignin. • The freestanding mats were flexible with BET specific surface area of ∼583 m 2 /g. • The mats were surface-deposited with Ag nanoparticles via the scCO 2 method. • Novel electrocatalytic systems of Ag/ECNFs exhibited high activities towards ORR. - Abstract: Ag nanoparticles (AgNPs) (11, 15, and 25 wt.%) were deposited on the surface of the freestanding and mechanically flexible mats consisting of lignin-derived electrospun carbon nanofibers (ECNFs) by the supercritical CO 2 method followed by the thermal treated at 180 °C. The electrochemical activity of Ag/ECNFs electrocatalyst systems towards oxygen reduction reaction (ORR) was studied in 0.1 M KOH aqueous solution using the rotating disk/rotating ring disk electrode (RDE/RRDE) technique. The SEM, TEM, and XRD results indicated that, the spherical AgNPs were uniformly distributed on the ECNF surface with sizes in the range of 2-10 nm. The electrocatalytic results revealed that, all of the Ag/ECNFs systems exhibited high activity in ORR and demonstrated close-to-theoretical four-electron pathway. In particular, the mass activity of 15 wt.% Ag/ECNFs system was the highest (119 mA mg −1 ), exceeding that of HiSPEC 4100™ commercial Pt/C catalyst (98 mA mg −1 ). This study suggested that the lignin-derived ECNF mats surface-deposited with AgNPs would be promising as cost-effective and highly efficient electrocatalyst for ORR in alkaline fuel cells

  18. Development of a General Aza-Cope Reaction Trigger Applied to Fluorescence Imaging of Formaldehyde in Living Cells.

    Science.gov (United States)

    Bruemmer, Kevin J; Walvoord, Ryan R; Brewer, Thomas F; Burgos-Barragan, Guillermo; Wit, Niek; Pontel, Lucas B; Patel, Ketan J; Chang, Christopher J

    2017-04-19

    Formaldehyde (FA) is a reactive signaling molecule that is continuously produced through a number of central biological pathways spanning epigenetics to one-carbon metabolism. On the other hand, aberrant, elevated levels of FA are implicated in disease states ranging from asthma to neurodegenerative disorders. In this context, fluorescence-based probes for FA imaging are emerging as potentially powerful chemical tools to help disentangle the complexities of FA homeostasis and its physiological and pathological contributions. Currently available FA indicators require direct modification of the fluorophore backbone through complex synthetic considerations to enable FA detection, often limiting the generalization of designs to other fluorophore classes. To address this challenge, we now present the rational, iterative development of a general reaction-based trigger utilizing 2-aza-Cope reactivity for selective and sensitive detection of FA in living systems. Specifically, we developed a homoallylamine functionality that can undergo a subsequent self-immolative β-elimination, creating a FA-responsive trigger that is capable of masking a phenol on a fluorophore or any other potential chemical scaffold for related imaging and/or therapeutic applications. We demonstrate the utility of this trigger by creating a series of fluorescent probes for FA with excitation and emission wavelengths that span the UV to visible spectral regions through caging of a variety of dye units. In particular, Formaldehyde Probe 573 (FAP573), based on a resorufin scaffold, is the most red-shifted and FA sensitive in this series in terms of signal-to-noise responses and enables identification of alcohol dehydrogenase 5 (ADH5) as an enzyme that regulates FA metabolism in living cells. The results provide a starting point for the broader use of 2-aza-Cope reactivity for probing and manipulating FA biology.

  19. Equilibrium coverage of OHad in correlation with platinum catalyzed fuel cell reactions in HClO4

    DEFF Research Database (Denmark)

    Deng, Yujia; Arenz, Matthias; Wiberg, Gustav Karl Henrik

    2015-01-01

    We employ a recently developed stripping protocol to examine the equilibrium coverage of oxygenated species and their influence on the oxygen reduction reaction (ORR) and the hydrogen oxidation reaction (HOR). In particular we aim to distinguish between dynamic and steady state conditions...

  20. Kinetics of Bio-Reactions

    DEFF Research Database (Denmark)

    Villadsen, John

    2015-01-01

    his chapter predicts the specific rates of reaction by means of a mathematical expression, the kinetics of the reaction. This expression can be derived through a mechanistic interpretation of an enzymatically catalyzed reaction, but it is essentially of empirical nature for cell reactions. The mo...

  1. Prior lactose glycation of caseinate via the Maillard reaction affects in vitro activities of the pepsin-trypsin digest toward intestinal epithelial cells.

    Science.gov (United States)

    Wang, X P; Zhao, X H

    2017-07-01

    The well-known Maillard reaction in milk occurs between lactose and milk proteins during thermal treatment, and its effects on milk nutrition and safety have been well studied. A lactose-glycated caseinate was prepared via this reaction and digested using 2 digestive proteases, pepsin and trypsin. The glycated caseinate digest was assessed for its in vitro activities on rat intestinal epithelial cells in terms of growth proliferation, anti-apoptotic effect, and differentiation induction using caseinate digest as reference, to verify potential effects of the Maillard reaction on these activities of caseinate digest to the cells. Two digests had proliferative and anti-apoptotic effects, and reached the highest effects at 0.02 g/L of digest concentration with treatment time of 24 h. In comparison with caseinate digest, glycated caseinate digest always showed weaker proliferative (5.3-14.2%) and anti-apoptotic (5.9-39.0%) effects, and was more toxic to the cells at 0.5 g/L of digest concentration with treatment time of 48 h. However, glycated caseinate digest at 2 incubation times of 4 to 7 d showed differentiation induction higher than caseinate digest, as it could confer the cells with increased activities in lactase (16.3-26.6%), sucrase (22.4-31.2%), and alkaline phosphatase (17.4-24.8%). Transmission electron microscopy observation results also confirmed higher differentiation induction of glycated caseinate digest. Amino acid loss and lactose glycation partially contributed to these decreased and enhanced activities of glycated caseinate digest, respectively. The Maillard reaction of caseinate and lactose is thus shown in this study to have effects on the activities of caseinate digest to intestinal epithelial cells. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  2. Comparison of the effect between an active specific immunotherapy using the immune reaction of a low-dose irradiated tumor tissue and that using irradiated tumor cells

    International Nuclear Information System (INIS)

    Ogawa, Yasuhiro; Maeda, Tomoho; Yoshida, Shoji; Yamamoto, Yoichi; Morita, Masaru

    1983-01-01

    The effect of the active specific immunotherapy using the immune reaction of a low-dose irradiated tumor tissue was compared with that of irradiated (10,000 rads) tumor cells on the transplanted MM46 tumor of female C3H/He mice after radiotherapy. MM46 tumor cells were inoculated into the right hind paws of mice. On the 6th day, irradiation with a dose of 3,000 rads was performed. On the 14th day, tumor cells and concomitant mononuclear cells which were separated from the low-dose irradiated tumor tissue (2,000 rads on the 6th day) were injected into the left hind paws of one group of the tumor-bearing mice. On the same day, irradiated MM46 tumor cells were injected into the left hind paws of another group of the tumor-bearing mice. Effectiveness of these two methods of active specific immunotherapy against tumor was evaluated by the regression of tumor and survival rate of mice. The active specific immunotherapy using the immune reaction of a low-dose irradiated tumor tissue was far more effective than irradiated tumor cells on this tumor system involved. (author)

  3. The drug efficacy and adverse reactions in a mouse model of oral squamous cell carcinoma treated with oxaliplatin at different time points during a day

    Directory of Open Access Journals (Sweden)

    Yang K

    2013-06-01

    Full Text Available Kai Yang,1,2 Ningbo Zhao,1 Dan Zhao,1,2 Dan Chen,1 Yadong Li1 1Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 2Chongqing Key Laboratory for Oral Diseases and Biomedical Sciences, Chongqing Medical University, Chongqing, People’s Republic of China Background: Recent studies have shown that the growth and proliferation of cancer cells in vivo exhibit circadian rhythm, and the efficacy and adverse reactions of platinum-based anticancer drugs administered at different times of the day vary significantly on colon cancer. However, since the circadian rhythms of growth and proliferation of various cancer cells often differ, the question of whether the administration of platinum anticancer drugs at different times of the day exerts significantly different efficacy and adverse effects on oral cancers remains to be elucidated. This study has compared the efficacy and adverse effects of oxaliplatin (L-OHP administration at different times during a day on oral squamous cell carcinoma in mice and has analyzed cellular circadian rhythms. Methods: The mouse model for oral squamous cell carcinoma was established in 75 nude mice, housed in a 12 hour light/12 hour dark cycle environment. The mice were randomly divided into five groups; four experimental groups were intravenously injected with L-OHP at four time points within a 24-hour period (4, 10, 16, and 22 hours after lights on [HALO]. The control group was intravenously injected with the same volume of saline. Treatment efficacy and adverse reactions were compared on the seventh day after the injection, at 22 HALO. The existence of circadian rhythms was determined by cosine analysis. Results: Only injections of L-OHP at 16 and 22 HALO significantly prolonged animal survival time. The adverse reactions in mice injected with L-OHP at 16 and 22 HALO were significantly less than those observed in mice administered L-OHP at 4 and 10 HALO

  4. Protective Effects of Maillard Reaction Products of Whey Protein Concentrate against Oxidative Stress through an Nrf2-Dependent Pathway in HepG2 Cells.

    Science.gov (United States)

    Pyo, Min Cheol; Yang, Sung-Yong; Chun, Su-Hyun; Oh, Nam Su; Lee, Kwang-Won

    2016-09-01

    Whey protein concentrate (WPC), which contains α-lactalbumin and β-lactoglobulin, is utilized widely in the food industry. The Maillard reaction is a complex reaction that produces Maillard reaction products (MRPs), which are associated with the formation of antioxidant compounds. In this study, the hepatoprotection activity of MRPs of WPC against oxidative stress through the nuclear factor-E2-related factor 2 (Nrf2)-dependent antioxidant pathway in HepG2 cells was examined. Glucose-whey protein concentrate conjugate (Glc-WPC) was obtained from Maillard reaction between WPC and glucose. The fluorescence intensity of Glc-WPC increased after 7 d compared to native WPC, and resulted in loss of 48% of the free amino groups of WPC. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns of Glc-WPC showed the presence of a high-molecular-weight portion. Treatment of HepG2 cells with Glc-WPC increased cell viability in the presence of oxidative stress, inhibited the generation of intracellular reactive oxygen species by tert-butyl hydroperoxide (t-BHP), and increased the glutathione level. Nrf2 translocation and Nrf2, reduced nicotinamide adenine dinucleotide phosphate (NAD(P)H)-quinone oxidoreductase 1 (NOQ1), heme oxygenase-1 (HO-1), glutamate-L-cysteine ligase (GCL)M and GCLC mRNA levels were increased by Glc-WPC. Also, Glc-WPC increased the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 and c-Jun N-terminal kinase (JNK). The results of this study demonstrate that Glc-WPC activates the Nrf2-dependent pathway through the phosphorylation of ERK1/2 and JNK in HepG2 cells, and induces production of antioxidant enzymes and phase II enzymes.

  5. Effect of reverse Boudouard reaction catalyst on the performance of solid oxide carbon fuel cells integrated with a dry gasifier

    International Nuclear Information System (INIS)

    Kim, Sun-Kyung; Mehran, Muhammad Taqi; Mushtaq, Usman; Lim, Tak-Hyoung; Lee, Jong-Won; Lee, Seung-Bok; Park, Seok-Joo; Song, Rak-Hyun

    2016-01-01

    Highlights: • The addition of K_2CO_3 catalyst in carbon fuel improves the performance of SO-CFC. • Thermal and electrochemical analyses done to elucidate the catalytic enhancement. • Material characterization of SO-CFC performed after long-term degradation test. - Abstract: A solid oxide carbon fuel cell (SO-CFC) integrated with a dry gasifier was operated on activated carbon fuel and the effect of adding a reverse Boudouard gasification catalyst on the performance and long-term operation characteristics of the SO-CFC was investigated. The reactivity of the carbon fuels for the Boudouard gasification reaction was analyzed by a thermal analysis at various operating conditions. The SO-CFC was then operated on gasified fuel gas consisting of CO_2 and CO obtained from the integrated dry gasifier. The SO-CFC operated on activated carbon fuel with 5 wt.% K_2CO_3 achieved a maximum power density of 202, 262, and 271 mW/cm"2 at 750, 800, and 850 °C, respectively; the SO-CFC fueled with activated carbon fuel without a catalyst meanwhile yielded maximum power density of 168 mW/cm"2 at 850 °C. By using electrochemical impedance spectroscopy, the effect of adding the catalyst on the gasification products and subsequently on the performance of the SO-CFC was studied. A long-term degradation test was conducted by continuously operating the SO-CFC at 50 mA/cm"2 for 518 h at 750 °C. During the long-term degradation test, the average degradation rate of the SO-CFC was found to be 183 mV/kh. The post-mortem SEM and XRD analyses of the SO-CFC after the long-term test revealed the presence of carbon deposits and oxidation of Ni at the anode, causing a relatively higher degree of degradation in the SO-CFC integrated with the dry gasifier during the long-term operation. The addition of the K_2CO_3 based dry gasification catalyst significantly enhances the performance of the SO-CFC integrated with dry gasification, but during long-term operation, the degradation rate is found

  6. Modelling non-homogeneous stochastic reaction-diffusion systems: the case study of gemcitabine-treated non-small cell lung cancer growth.

    Science.gov (United States)

    Lecca, Paola; Morpurgo, Daniele

    2012-01-01

    Reaction-diffusion based models have been widely used in the literature for modeling the growth of solid tumors. Many of the current models treat both diffusion/consumption of nutrients and cell proliferation. The majority of these models use classical transport/mass conservation equations for describing the distribution of molecular species in tumor spheroids, and the Fick's law for describing the flux of uncharged molecules (i.e oxygen, glucose). Commonly, the equations for the cell movement and proliferation are first order differential equations describing the rate of change of the velocity of the cells with respect to the spatial coordinates as a function of the nutrient's gradient. Several modifications of these equations have been developed in the last decade to explicitly indicate that the tumor includes cells, interstitial fluids and extracellular matrix: these variants provided a model of tumor as a multiphase material with these as the different phases. Most of the current reaction-diffusion tumor models are deterministic and do not model the diffusion as a local state-dependent process in a non-homogeneous medium at the micro- and meso-scale of the intra- and inter-cellular processes, respectively. Furthermore, a stochastic reaction-diffusion model in which diffusive transport of the molecular species of nutrients and chemotherapy drugs as well as the interactions of the tumor cells with these species is a novel approach. The application of this approach to he scase of non-small cell lung cancer treated with gemcitabine is also novel. We present a stochastic reaction-diffusion model of non-small cell lung cancer growth in the specification formalism of the tool Redi, we recently developed for simulating reaction-diffusion systems. We also describe how a spatial gradient of nutrients and oncological drugs affects the tumor progression. Our model is based on a generalization of the Fick's first diffusion law that allows to model diffusive transport in non

  7. Study of the oxygen reduction reaction using Pt-Rare earths (La, Ce, Er) electrocatalysts for application of PEM fuel cells

    International Nuclear Information System (INIS)

    Gomes, Thiago Bueno

    2013-01-01

    The complexity of the oxygen reduction reaction (ORR) and its potential losses make it responsible for the most part of efficiency losses at the Fuel Cells. For this reaction the electrocatalyst witch is most appropriated and shows better performance is platinum, a noble metal that elevates the cost, raising barriers for Fuel Cells technology to enter the market. First this work focuses on reducing the amount of platinum used in the cathode, by being replaced by rare earths. The most common methods of synthesis involves a large amount of steps and this work proposed to prepare the electrocatalyst through a simpler way that would not take so many steps and time to be done. Using an ultrasound mixer the electrocatalyst was prepared mixing platinum supported on carbon black and the rare earths lanthanum, cerium and erbium oxides to be applied in a half-cell study of the ORR. The Koutecky-Levich plots shows that among the electrocatalysts prepared the Pt80Ce20/C had the catalytic activity close to the commercial BASF platinum on carbon black, suggesting that the reaction was taken by the 4-electron path. As found in some works in literature, among the rare earth used to study the ORR, cerium is the one witch shows the better performance because it is able to store and provide oxygen. This feature is of great interest for the ORR because this reaction is first order to the oxygen concentration. Results show that is possible to reduce the amount of platinum maintaining the same electrocatalyst activity. (author)

  8. Differential effect of gamma-irradiated and heat-treated lymphocytes on T cell activation, and interleukin-2 and interleukin-3 release in the human mixed lymphocyte reaction

    International Nuclear Information System (INIS)

    Loertscher, R.; Abbud-Filho, M.; Leichtman, A.B.; Ythier, A.A.; Williams, J.M.; Carpenter, C.B.; Strom, T.B.

    1987-01-01

    Heat-inactivated (45 degrees C/1 hr) lymphocytes selectively activate suppressor T cells in the mixed lymphocyte reaction (MLR), while no significant proliferation and cytotoxic T lymphocyte activation can be detected. It is not well understood why hyperthermic treatment abolishes the stimulatory capacity of lymphocytes since HLA-DR molecules remain detectable immediately following heat exposure. In order to further characterize the requirements for Ts activation we studied the effects of hyperthermic treatment on cellular protein and DNA synthesis and cell surface protein expression in proliferating T and B cells; interleukin (IL)-1, IL-2, and IL-3 release following allogeneic stimulation with heat treated cells (HMLR); and IL-2 receptor expression as an indicator of T cell activation in the HMLR. Hyperthermic treatment reduced cellular protein synthesis as estimated by 14 C-leucine uptake to about 15%, and DNA synthesis ( 3 H-thymidine incorporation) to about 5% of untreated control cells. In contrast to y-irradiated cells, viability of heated cells rapidly declined within the first 24 hr. Hyperthermic treatment doubled binding of mouse immunoglobulin paralleled by an increased expression of IL-2 and transferrin receptors, while expression of HLA-DR and 4F2 proteins appeared unchanged. Stimulation with heated cells triggered the release of IL-1- and an IL-3-like bioactivity but did not induce IL-2 synthesis and/or release, thus explaining the lack of proliferation in the HMLR. Addition of exogenous IL-2 but not IL-1 restored HMLR proliferation. A comparison of allostimulation with y-irradiated and heat-treated cells revealed that significantly fewer T cells were induced to express IL-2 receptors at day 3 (14% vs. 8%, P less than 0.001) and at day 6 (42% vs. 21%, P less than 0.05) with heat-inactivated stimulators

  9. Glycosyltransferases as marker genes for the quantitative polymerase chain reaction-based detection of circulating tumour cells from blood samples of patients with breast cancer undergoing adjuvant therapy.

    Science.gov (United States)

    Kölbl, Alexandra C; Hiller, Roman A; Ilmer, Mathias; Liesche, Friederike; Heublein, Sabine; Schröder, Lennard; Hutter, Stefan; Friese, Klaus; Jeschke, Udo; Andergassen, Ulrich

    2015-08-01

    Altered glycosylation is a predominant feature of tumour cells; it serves for cell adhesion and detachment, respectively, and facilitates the immune escape of these cells. Therefore changes in the expression of glycosyltransferase genes could help to identify circulating tumour cells (CTCs) in the blood samples of cancer patients using a quantitative polymerase chain reaction (PCR) approach. Blood samples of healthy donors were inoculated with certain numbers of established breast cancer cell line cells, thus creating a model system. These samples were analysed by quantitative PCR for the expression of six different glycosyltransferase genes. The three genes with the best results in the model system were consecutively applied to samples from adjuvant breast cancer patients and of healthy donors. FUT3 and GALNT6 showed the highest increase in relative expression, while GALNT6 and ST3GAL3 were the first to reach statistically significant different ∆CT-values comparing the sample with and without addition of tumour cells. These three genes were applied to patient samples, but did not show any significant results that may suggest the presence of CTCs in the blood. Although the relative expression of some of the glycosyltransferase genes exhibited reasonable results in the model system, their application to breast cancer patient samples will have to be further improved, e.g. by co-analysis of patient blood samples by gold-standard methods.

  10. THE RELATIONSHIP OF THE GENERAL REACTION SCORE WITH THE NATURAL KILLER CELLS ACTIVITY AMONG WOMEN WITH AIRCRAFT NOISE EXPOSURE IN THE AREA OF ADI SOEMARMO AIRPORT SOLO (Hubungan antara general reaction score dengan aktivitas sel NK pada wanita

    Directory of Open Access Journals (Sweden)

    Hartono Hartono

    2011-07-01

    performance. For other effects such as changes in the immune system and birth defects, the evidence is limited.The aims of the research is  to find out the correlation of the general reaction score with The Natural Killer cell activity among women with aircraft noise exposure in the area of Adi Sumarmo Airport Solo.The research findings are expected to contribute to the scientific knowledge development and to give benefits for local government and among people in the area of Adi Sumarmo Airport in preventing the effect of aircraft noise. The research design was an analytical survey with a cross sectional approach, taking place at the Dibal and Gagak Sipat Village, Ngemplak Sub district, Boyolali District. The research was conducted from July 2008 to June 2009. The number of respondens was 39. They were divided into 3 groups; group 1 was exposed to 92.29 dB of noise level (13 respondents; group 2 was exposed to 71.79 dB of noise level (13 respondents; and group 3 was exposed to 52.17 dB of noise level (13 respondents. The samples were taken using simple random sampling. The data were analyzed by Pearson Correlation and Anova followed by Post Hoc Test using LSD test completed with Homogenous Subsets. The Anova test showed that there was significant differences in the general reaction score among all groups (p = 0.000. The Pearson correlation test showed that there was a negative association between the general reaction score with the Natural Killer cells activity (r = - 0.613; p < 0.05.

  11. Direct evidence for a chronic CD8+-T-cell-mediated immune reaction to tax within the muscle of a human T-cell leukemia/lymphoma virus type 1-infected patient with sporadic inclusion body myositis.

    Science.gov (United States)

    Ozden, Simona; Cochet, Madeleine; Mikol, Jacqueline; Teixeira, Antonio; Gessain, Antoine; Pique, Claudine

    2004-10-01

    Human T-cell leukemia/lymphoma virus type 1 (HTLV-1) infection can lead to the development of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), concomitantly with or without other inflammatory disorders such as myositis. These pathologies are considered immune-mediated diseases, and it is assumed that migration within tissues of both HTLV-1-infected CD4(+) T cells and anti-HTLV-1 cytotoxic T cells represents a pivotal event. However, although HTLV-1-infected T cells were found in inflamed lesions, the antigenic specificity of coinfiltrated CD8(+) T cells remains to be determined. In this study, we performed both ex vivo and in situ analyses using muscle biopsies obtained from an HTLV-1-infected patient with HAM/TSP and sporadic inclusion body myositis. We found that both HTLV-1-infected CD4(+) T cells and CD8(+) T cells directed to the dominant Tax antigen can be amplified from muscle cell cultures. Moreover, we were able to detect in two successive muscle biopsies both tax mRNA-positive mononuclear cells and T cells recognized by the Tax11-19/HLA-A*02 tetramer and positive for perforin. These findings provide the first direct demonstration that anti-Tax cytotoxic T cells are chronically recruited within inflamed tissues of an HTLV-1 infected patient, which validates the cytotoxic immune reaction model for the pathogenesis of HTLV-1-associated inflammatory disease.

  12. Designing primers and evaluation of the efficiency of propidium monoazide - Quantitative polymerase chain reaction for counting the viable cells of Lactobacillus gasseri and Lactobacillus salivarius.

    Science.gov (United States)

    Lai, Chieh-Hsien; Wu, Sih-Rong; Pang, Jen-Chieh; Ramireddy, Latha; Chiang, Yu-Cheng; Lin, Chien-Ku; Tsen, Hau-Yang

    2017-07-01

    The purpose of this study is to evaluate the efficiency of using propidium monoazide (PMA) real-time quantitative polymerase chain reaction (qPCR) to count the viable cells of Lactobacillus gasseri and Lactobacillus salivarius in probiotic products. Based on the internal transcription spacer and 23S rRNA genes, two primer sets specific for these two Lactobacillus species were designed. For a probiotic product, the total deMan Rogosa Sharpe plate count was 8.65±0.69 log CFU/g, while for qPCR, the cell counts of L. gasseri and L. salivarius were 8.39±0.14 log CFU/g and 8.57±0.24 log CFU/g, respectively. Under the same conditions, for its heat-killed product, qPCR counts for L. gasseri and L. salivarius were 6.70±0.16 log cells/g and 7.67±0.20 log cells/g, while PMA-qPCR counts were 5.33±0.18 log cells/g and 5.05±0.23 log cells/g, respectively. For cell dilutions with a viable cell count of 8.5 log CFU/mL for L. gasseri and L. salivarius, after heat killing, the PMA-qPCR count for both Lactobacillus species was near 5.5 log cells/mL. When the PMA-qPCR counts of these cell dilutions were compared before and after heat killing, although some DNA might be lost during the heat killing, significant qPCR signals from dead cells, i.e., about 4-5 log cells/mL, could not be reduced by PMA treatment. Increasing PMA concentrations from 100 μM to 200 μM or light exposure time from 5 minutes to 15 minutes had no or, if any, only minor effect on the reduction of qPCR signals from their dead cells. Thus, to differentiate viable lactic acid bacterial cells from dead cells using the PMA-qPCR method, the efficiency of PMA to reduce the qPCR signals from dead cells should be notable. Copyright © 2016. Published by Elsevier B.V.

  13. Designing primers and evaluation of the efficiency of propidium monoazide – Quantitative polymerase chain reaction for counting the viable cells of Lactobacillus gasseri and Lactobacillus salivarius

    Directory of Open Access Journals (Sweden)

    Chieh-Hsien Lai

    2017-07-01

    Full Text Available The purpose of this study is to evaluate the efficiency of using propidium monoazide (PMA real-time quantitative polymerase chain reaction (qPCR to count the viable cells of Lactobacillus gasseri and Lactobacillus salivarius in probiotic products. Based on the internal transcription spacer and 23S rRNA genes, two primer sets specific for these two Lactobacillus species were designed. For a probiotic product, the total deMan Rogosa Sharpe plate count was 8.65±0.69 log CFU/g, while for qPCR, the cell counts of L. gasseri and L. salivarius were 8.39±0.14 log CFU/g and 8.57±0.24 log CFU/g, respectively. Under the same conditions, for its heat-killed product, qPCR counts for L. gasseri and L. salivarius were 6.70±0.16 log cells/g and 7.67±0.20 log cells/g, while PMA-qPCR counts were 5.33±0.18 log cells/g and 5.05±0.23 log cells/g, respectively. For cell dilutions with a viable cell count of 8.5 log CFU/mL for L. gasseri and L. salivarius, after heat killing, the PMA-qPCR count for both Lactobacillus species was near 5.5 log cells/mL. When the PMA-qPCR counts of these cell dilutions were compared before and after heat killing, although some DNA might be lost during the heat killing, significant qPCR signals from dead cells, i.e., about 4–5 log cells/mL, could not be reduced by PMA treatment. Increasing PMA concentrations from 100 μM to 200 μM or light exposure time from 5 minutes to 15 minutes had no or, if any, only minor effect on the reduction of qPCR signals from their dead cells. Thus, to differentiate viable lactic acid bacterial cells from dead cells using the PMA-qPCR method, the efficiency of PMA to reduce the qPCR signals from dead cells should be notable.

  14. The Effect of Cell Phone Conversation on Drivers’ Reaction Time to Audio Stimulus: Investigating the Theory of Multiple Resources and Central Resource of Attention

    Directory of Open Access Journals (Sweden)

    Seyed Kazem Mousavi-Sadati

    2011-01-01

    Full Text Available Objective: This research was aimed at investigating the theory of multiple resources and central resource of attention on secondary task performance of talking with two types of cell phone during driving. Materials & Methods: Using disposal sampling, 25 male participants were selected and their reaction to auditory stimulus in three different driving conditions (no conversation with phone, conversation with handheld phone and hands-free phone were recorded. Driving conditions have been changed from a participant to another participant in order to control the sequence of tests and participants familiarity with the test conditions. Results: the results of data analysis with descriptive statistics and Mauchly’s Test of Sphericity, One- factor repeated measures ANOVA and Paired-Samples T test showed that different driving conditions can affect the reaction time (P0.001. Phone Conversation with hands-free phone increases drivers’ simple reaction time to auditory stimulus (P<0.001. Using handheld phone does not increase drivers’ reaction time to auditory stimulus over hands-free phone (P<0.001. Conclusion: The results confirmed that the performance quality of dual tasks and multiple tasks can be predicted by Four-dimensional multiple resources model of attention and all traffic laws in connection with the handheld phone also have to be spread to the use of hands-free phone.

  15. Optimisation of a quantitative polymerase chain reaction-based strategy for the detection and quantification of human herpesvirus 6 DNA in patients undergoing allogeneic haematopoietic stem cell transplantation

    Directory of Open Access Journals (Sweden)

    Miriam YH Ueda

    2015-06-01

    Full Text Available Human herpesvirus 6 (HHV-6 may cause severe complications after haematopoietic stem cell transplantation (HSCT. Monitoring this virus and providing precise, rapid and early diagnosis of related clinical diseases, constitute essential measures to improve outcomes. A prospective survey on the incidence and clinical features of HHV-6 infections after HSCT has not yet been conducted in Brazilian patients and the impact of this infection on HSCT outcome remains unclear. A rapid test based on real-time quantitative polymerase chain reaction (qPCR has been optimised to screen and quantify clinical samples for HHV-6. The detection step was based on reaction with TaqMan® hydrolysis probes. A set of previously described primers and probes have been tested to evaluate efficiency, sensitivity and reproducibility. The target efficiency range was 91.4% with linearity ranging from 10-106 copies/reaction and a limit of detection of five copies/reaction or 250 copies/mL of plasma. The qPCR assay developed in the present study was simple, rapid and sensitive, allowing the detection of a wide range of HHV-6 loads. In conclusion, this test may be useful as a practical tool to help elucidate the clinical relevance of HHV-6 infection and reactivation in different scenarios and to determine the need for surveillance.

  16. Comparison of the insulin reaction of peripheral blood T cells between healthy Holstein dairy cows and JB during the periparturient period.

    Science.gov (United States)

    Ohtsuka, Hiromichi; Kitagawa, Madoka; Kohiruimaki, Masayuki; Tanami, Erika; Masui, Machiko; Hayashi, Tomohito; Ando, Takaaki; Watanabe, Daisaku; Koiwa, Masateru; Sato, Shigeru; Kawamura, Seiichi

    2006-11-01

    To compare the changes in the insulin reaction of Holstein dairy cows and Japanese Black cows (JB) during the periparturient period, the insulin resistance test in vivo and lymphocytes proliferation with insulin in vitro were performed. Ten healthy Holstein dairy cows (Holstein group) and 10 healthy JB cows (JB group) used in this study were observed on days 60, 40, and 20 before calving and days 7 and 20 after calving. In insulin resistance reaction in vivo and in vitro, a low insulin-stimulated glucose disposal rate and lymphocyte proliferation with insulin were observed in the Holstein group compared with the JB group during the experimental period. An analysis of the lymphocytes cultured with insulin showed that the percentage of CD4+CD45R- T cells in the Holstein group was significantly lower than that of the JB group before day 20. These findings indicate that T cells reaction to insulin in healthy periparturient Holstein cows is lower than that in Japanese Black.

  17. Interfacial charge recombination via the triplet state? Mimicry of photoprotection in the photosynthetic process with a dye-sensitized TiO 2 solar cell reaction

    Science.gov (United States)

    Weng, Yu-Xiang; Li, Long; Liu, Yin; Wang, Li; Yang, Guo-Zhen; Sheng, Jian-Qun

    2002-04-01

    Evidence for the photoinduced charge recombination to the excited-triplet state has been observed in chemical solar cell reaction consisting of dye-sensitized TiO 2 colloidal ethanol solution, which mimicks the photoprotection function in the photosynthetic units. The dye is all -trans-retinoic acid, a structural analog of β-carotenoid. Two channels of charge recombination, i.e., through triplet and ground states were observed by nano-second flash photolysis. The possibility of applying the function of photoprotection to the synthetic solar cell is discussed, which provides a potential entry of molecular engineering of the dye to improve the long term stability of the synthetic solar cell.

  18. A computational method for the coupled solution of reaction-diffusion equations on evolving domains and manifolds: Application to a model of cell migration and chemotaxis.

    Science.gov (United States)

    MacDonald, G; Mackenzie, J A; Nolan, M; Insall, R H

    2016-03-15

    In this paper, we devise a moving mesh finite element method for the approximate solution of coupled bulk-surface reaction-diffusion equations on an evolving two dimensional domain. Fundamental to the success of the method is the robust generation of bulk and surface meshes. For this purpose, we use a novel moving mesh partial differential equation (MMPDE) approach. The developed method is applied to model problems with known analytical solutions; these experiments indicate second-order spatial and temporal accuracy. Coupled bulk-surface problems occur frequently in many areas; in particular, in the modelling of eukaryotic cell migration and chemotaxis. We apply the method to a model of the two-way interaction of a migrating cell in a chemotactic field, where the bulk region corresponds to the extracellular region and the surface to the cell membrane.

  19. Cell-mediated immunity to histocompatibility antigens : controlling factors, with emphasis on Graft-versus-host reactions in mice

    NARCIS (Netherlands)

    H. Bril (Herman)

    1984-01-01

    textabstractGraft-versus-Host (GvH) disease is characterized by weight loss, diarrhea, skin lesions, hypofunction of the immune system with concomitant infections, etc. This syndrome is potentially lethal. GvH reactions, which underly this disease, may occur when immunocompetent T lymphocytes are

  20. Rules for biocatalyst and reaction engineering to implement effective, NAD(P)H-dependent, whole cell bioreductions

    DEFF Research Database (Denmark)

    Kratzer, Regina; Woodley, John; Nidetzky, Bernd

    2015-01-01

    recycling mode and reaction conditions represent design options that strongly affect bioreduction efficiency. In this paper, each option was critically scrutinized and decision rules formulated based on well-described literature examples. The development chain was visualized as a decision-tree that can...

  1. Selective oxidations in microstructured catalytic reactions - A review and an overview of own work on fuel processing for fuel cells

    NARCIS (Netherlands)

    Hessel, V.; Kolb, G.A.; Cominos, V.; Loewe, H.; Nikolaidis, G.; Zapf, R.; Ziogas, A.; Schouten, J.C.; Delsman, E.R.; Croon, de M.H.J.M.; Santamaria, J.; Iglesia, de la O.; Mallada, R.

    2006-01-01

    This review is concerned about catalytic gas-phase oxidation reactions in microreactors, typically being performed in wall-coated microchannels. Not included are liquid and gas-liquid oxidations which are typically done in reactor designs different from the ones considered here. The first part of

  2. Different DNA methylation patterns detected by the Amplified Methylation Polymorphism Polymerase Chain Reaction (AMP PCR technique among various cell types of bulls

    Directory of Open Access Journals (Sweden)

    Carroll Bernie

    2010-03-01

    Full Text Available Abstract Background The purpose of this study was to apply an arbitrarily primed methylation sensitive polymerase chain reaction (PCR assay called Amplified Methylation Polymorphism Polymerase Chain Reaction (AMP PCR to investigate the methylation profiles of somatic and germ cells obtained from Holstein bulls. Methods Genomic DNA was extracted from sperm, leukocytes and fibroblasts obtained from three bulls and digested with a methylation sensitive endonuclease (HpaII. The native genomic and enzyme treated DNA samples were used as templates in an arbitrarily primed-PCR assay with 30 sets of single short oligonucleotide primer. The PCR products were separated on silver stained denaturing polyacrylamide gels. Three types of PCR markers; digestion resistant-, digestion sensitive-, and digestion dependent markers, were analyzed based on the presence/absence polymorphism of the markers between the two templates. Results Approximately 1,000 PCR markers per sample were produced from 27 sets of primer and most of them (>90% were digestion resistant markers. The highest percentage of digestion resistant markers was found in leukocytic DNA (94.8% and the lowest in fibroblastic DNA (92.3%, P ≤ 0.05. Spermatozoa contained a higher number of digestion sensitive markers when compared with the others (3.6% vs. 2.2% and 2.6% in leukocytes and fibroblasts respectively, P ≤ 0.05. Conclusions The powerfulness of the AMP PCR assay was the generation of methylation-associated markers without any prior knowledge of the genomic sequence. The data obtained from different primers provided an overview of genome wide DNA methylation content in different cell types. By using this technique, we found that DNA methylation profile is tissue-specific. Male germ cells were hypomethylated at the HpaII locations when compared with somatic cells, while the chromatin of the well-characterized somatic cells was heavily methylated when compared with that of the versatile somatic

  3. A CFD analysis of transport phenomena and electrochemical reactions in a tubular-shaped PEM fuel cell

    OpenAIRE

    Maher A.R. Sadiq Al-Baghdadi

    2013-01-01

    A fuel cell is most interesting new power source because it solves not only the environment problem but also natural resource exhaustion problem. CFD modeling and simulation for heat and mass transport in PEM fuel cells are being used extensively in researches and industrial applications to gain better understanding of the fundamental processes and to optimize fuel cell designs before building a prototype for engineering application. In this research, full three-dimensional, non-isothermal co...

  4. Signal function of cytokinin 6-benzylaminopurine in the reaction of Triticum aestivum L. mesophyll cells to hyperthermia

    Directory of Open Access Journals (Sweden)

    M. M. Musienko

    2014-12-01

    Full Text Available The signaling effect of 6-benzylaminopurine (BAP on leaf mesophyll cells of Triticum aestivum L. under hyperthermic conditions was studied­. It was found that BAP regulated photosynthetic pigment, hydrogen peroxide content and activity of antioxidant enzymes, namely superoxide dismutase, ascorbate peroxidase and catalase under high-temperature conditions. The additive effect of BAP and high temperature on the activation of cell antioxidant systems was demonstrated. BAP regulated reducing processes in mesophyll leaf cells under high-temperature conditions.

  5. Nuclear reactions

    International Nuclear Information System (INIS)

    Lane, A.M.

    1980-01-01

    In reviewing work at Harwell over the past 25 years on nuclear reactions it is stated that a balance has to be struck in both experiment and theory between work on cross-sections of direct practical relevance to reactors and on those relevant to an overall understanding of reaction processes. The compound nucleus and direct process reactions are described. Having listed the contributions from AERE, Harwell to developments in nuclear reaction research in the period, work on the optical model, neutron capture theory, reactions at doorway states with fine structure, and sum-rules for spectroscopic factors are considered in more detail. (UK)

  6. The Maillard reaction of a shrimp by-product protein hydrolysate: chemical changes and inhibiting effects of reactive oxygen species in human HepG2 cells.

    Science.gov (United States)

    Zha, Fengchao; Wei, Binbin; Chen, Shengjun; Dong, Shiyuan; Zeng, Mingyong; Liu, Zunying

    2015-06-01

    Recently, much attention has been given to improving the antioxidant activity of protein hydrolysates via the Maillard reaction, but little is known about the cellular antioxidant activity of Maillard reaction products (MRPs) from protein hydrolysates. We first investigated chemical characterization and the cellular antioxidant activity of MRPs in a shrimp (Litopenaeus vannamei) by-product protein hydrolysate (SBH)-glucose system at 110 °C for up to 10 h of heating. Solutions of SBH and glucose were also heated alone as controls. The Maillard reaction greatly resulted in the increase of hydroxymethylfurfural (HMF) and browning intensity, high molecular weight fraction, and reduction of the total amino acid in SBH with the heating time, which correlated well with the free radical scavenging activity of MRPs. MRPs had stronger inhibiting effects on oxidative stress of human HepG2 cells than the original SBH, and its cellular antioxidant activity strongly correlated with free radical scavenging activity, but less affected by the browning intensity and HMF level. The caramelization of glucose partially affected the HMF level and free radical scavenging activity of MRPs, but it was not related to the cellular antioxidant activity. The cellular antioxidant activity of MRPs for 5 h of heating time appeared to reach a maximum level, which was mainly due to carbonyl ammonia condensation reaction. In conclusion, the Maillard reaction is a potential method to increase the cellular antioxidant activity of a shrimp by-product protein hydrolysate, but the higher HMF levels and the lower amino acid content in MRPs should also be considered.

  7. Effect of cathode porosity on the Lithium-air cell oxygen reduction reaction – A rotating ring-disk electrode investigation

    International Nuclear Information System (INIS)

    Seo, Jeongwook; Sankarasubramanian, Shrihari; Singh, Nikhilendra; Mizuno, Fuminori; Takechi, Kensuke; Prakash, Jai

    2017-01-01

    The kinetics of the oxygen reduction reaction (ORR) on the practical air cathode in a Lithium-air cell, which is conventionally composed of porous carbon with or without catalysts supported on it, was investigated. The mechanism and kinetics of the oxygen reduction reaction (ORR) was studied on a porous carbon electrode in an oxygen saturated solution of 0.1 M Lithium bis-trifluoromethanesulfonimide (LiTFSI) in Dimethoxyethane (DME) using cyclic voltammetery (CV) and the rotating ring-disk electrode (RRDE) technique. The oxygen reduction and evolution reactions were found to occur at similar potentials to those observed on a smooth, planar glassy carbon (GC) electrode. The effect of porosity and the resultant increase in surface area were readily observed in the increase in the transient time required for the intermediates to reach the ring and the much larger disk currents (compared to smooth, planar GC) recorded respectively. The RRDE data was analyzed using a kinetic model previously developed by us and the rate constants for the elementary reactions were calculated. The rates constant for the electrochemical reactions were found to be similar in magnitude to the rate constants calculated for smooth GC disks. The porosity of the electrode was found to decrease the rate of desorption of the intermediate and the product and delay their diffusion by shifting it from a Fickian regime in the electrolyte bulk to the Knudsen regime in the film pores. Thus, it is shown that the effect of the electrode porosity on the kinetics of the ORR is physical rather than electrochemical.

  8. The bio-complex "reaction pattern in vertebrate cells" reduces cytokine-induced cellular adhesion molecule mRNA expression in human endothelial cells by attenuation of NF-kappaB translocation.

    Science.gov (United States)

    Rönnau, Cindy; Liebermann, Herbert E H; Helbig, Franz; Staudt, Alexander; Felix, Stephan B; Ewert, Ralf; Landsberger, Martin

    2009-02-28

    The bio-complex "reaction pattern in vertebrate cells" (RiV) is mainly represented by characteristic exosome-like particles--probably as reaction products of cells to specific stress. The transcription factor NF-kappaB plays a central role in inflammation. We tested the hypothesis that RiV particle preparations (RiV-PP) reduce cellular adhesion molecule (CAM) expression (ICAM-1, VCAM-1, E-selectin) by the attenuation of NF-kappaB translocation in human umbilical vein endothelial cells (HUVEC). After 4 hours, pre-incubation of HUVEC with RiV-PP before stimulation with TNF-alpha significantly reduced ICAM-1 (65.5+/-10.3%) and VCAM-1 (71.1+/-12.3%) mRNA expression compared to TNF-alpha-treated cells (100%, n=7). ICAM-1 surface expression was significantly albeit marginally reduced in RiV/TNF-alpha- treated cells (92.0+/-5.6%, n=4). No significant effect was observed on VCAM-1 surface expression. In RiV/TNF-alpha-treated cells (n=4), NF-kappaB subunits p50 (85.7+/-4.1%) and p65 (85.0+/-1.8%) nuclear translocation was significantly reduced. RiV-PP may exert an anti-inflammatory effect in HUVEC by reducing CAM mRNA expression via attenuation of p50 and p65 translocation.

  9. Evaluating the impact of substrate and product concentration on a whole-cell biocatalyst during a Baeyer-Villiger reaction

    DEFF Research Database (Denmark)

    Shitu, J. O.; Chartrain, M.; Woodley, John

    2009-01-01

    The presence of high concentrations of substrate or product may impede the optimal functioning of a biocatalyst, more so in the case of whole cell biocatalysts where the metabolic status of the cells may be compromised. In this article we investigate these effects using as an example the Baeyer-V...

  10. Comparison of the reaction of bone-derived cells to enhanced MgCl2-salt concentrations.

    Science.gov (United States)

    Burmester, Anna; Luthringer, Bérengère; Willumeit, Regine; Feyerabend, Frank

    2014-01-01

    Magnesium-based implants exhibit various advantages such as biodegradability and potential for enhanced in vivo bone formation. However, the cellular mechanisms behind this possible osteoconductivity remain unclear. To determine whether high local magnesium concentrations can be osteoconductive and exclude other environmental factors that occur during the degradation of magnesium implants, magnesium salt (MgCl2) was used as a model system. Because cell lines are preferred targets in studies of non-degradable implant materials, we performed a comparative study of 3 osteosarcoma-derived cell lines (MG63, SaoS2 and U2OS) with primary human osteoblasts. The correlation among cell count, viability, cell size and several MgCl2 concentrations was used to examine the influence of magnesium on proliferation in vitro. Moreover, bone metabolism alterations during proliferation were investigated by analyzing the expression of genes involved in osteogenesis. It was observed that for all cell types, the cell count decreases at concentrations above 10 mM MgCl2. However, detailed analysis showed that MgCl2 has a relevant but very diverse influence on proliferation and bone metabolism, depending on the cell type. Only for primary cells was a clear stimulating effect observed. Therefore, reliable results demonstrating the osteoconductivity of magnesium implants can only be achieved with primary osteoblasts.

  11. Molecular mechanism of cell damage and protection against ionizing radiation. Communication 3. Correlation between the protective effect and development of a non-specific reaction

    International Nuclear Information System (INIS)

    Veksler, A.M.; Ermekova, V.M.; Kozlovich, L.I.

    1975-01-01

    The dynamics of reversible unspecific reaction (UR) of chinese hamster fibroblast cell culture to hypothermia and cysteamine addition has been studied. A correlation between UR development and radioresistance has been established. The post-irradiation protection has been shown to grow undulatorilly o cysteamine addition at different times after irradiation. This is explained by superimposition of two processes: realization of latent lesions which is delayed by UR development, and repair of these lesions by the enzymatic system the activity of which changes periodicallY, also as a result of UR development

  12. Process limitations of a whole-cell P450 catalyzed reaction using a CYP153A-CPR fusion construct expressed in Escherichia coli

    DEFF Research Database (Denmark)

    Lundemo, M. T.; Notonier, S.; Striedner, G.

    2016-01-01

    fatty acids at the terminal position. ω-Hydroxylated fatty acids can be used in the field of high-end polymers and in the cosmetic and fragrance industry. Here, we have identified the limitations for implementation of a whole-cell P450-catalyzed reaction by characterizing the chosen biocatalyst as well......Cytochrome P450s are interesting biocatalysts due to their ability to hydroxylate non-activated hydrocarbons in a selective manner. However, to date only a few P450-catalyzed processes have been implemented in industry due to the difficulty of developing economically feasible processes...

  13. Detection of human papilloma virus (HPV and human immunodeficiency virus (HIV in oral squamous cell carcinoma: A polymerized chain reaction (PCR study

    Directory of Open Access Journals (Sweden)

    Suresh Dirasantchu

    2015-01-01

    Full Text Available Aims and Objectives: Certain strains of human papillomavirus (HPV have been shown to be etiologically related to the development of uterine, cervical, and other genital cancers, but their role in the development of malignancies at other sites is less well established. Previous studies have shown HPV in tumors of the head and neck, but its prevalence has varied depending on the detection methods and the types of tumor and/or tissue examined. This study was undertaken for the detection of high-risk HPV types 16 and 18 and human immunodeficiency virus (HIV in oral squamous cell carcinoma. Materials and Methods: Twenty-five patients histologically diagnosed with oral squamous cell carcinoma and 10 apparently normal persons as controls were selected for the present study. Two biopsy specimens were removed surgically by incision biopsy for histopathological examination and polymerized chain reaction (PCR study. Results: Out of 25 oral squamous cell carcinoma subjects, 8 were found to be HPV positive in PCR. Out of these eight subjects, four had HPV 16 and the other four had other genotypes, and one subject was HIV positive. Conclusion: The conclusion drawn from the present study was that well-defined risk factors like HPV may play a prominent role in the development of oral squamous cell carcinomas, in addition to other risk factors. Further studies with a larger sample size are necessary to arrive at conclusions and to explore the relationship of HPV and HIV in oral squamous cell carcinoma.

  14. Detection of clonal T-cell receptor beta and gamma chain gene rearrangement by polymerase chain reaction and capillary gel electrophoresis.

    Science.gov (United States)

    Fan, Hongxin; Robetorye, Ryan S

    2013-01-01

    Although established diagnostic criteria exist for mature T-cell neoplasms, a definitive diagnosis of a T-cell lymphoproliferative disorder cannot always be obtained using more conventional techniques such as flow cytometric immunophenotyping, conventional cytogenetics, fluorescence in situ hybridization, or immunohistochemistry. However, because T-cell malignancies contain identically rearranged T-cell receptor gamma (TCRG) and/or beta (TCRB) genes, the polymerase chain reaction (PCR) can be a fast, convenient, and dependable option to identify clonal T-cell processes. This chapter describes the use of PCR and capillary electrophoresis to identify clonal TCRB and TCRG gene rearrangements (TCRB and TCRG PCR) using a commercially available method employing multiple multiplex PCR tubes that was originally developed as the result of a large European BIOMED-2 collaborative study (Invivoscribe Technologies). The core protocol for the TCRB assay involves the use of three separate multiplex master mix tubes. Tubes A and B target the framework regions within the variable and joining regions of the TCRB gene, and Tube C targets the diversity and joining regions of the TCRB gene. The core protocol for the TCRG assay utilizes two multiplex master mix tubes (Tubes A and B) that target the variable and joining regions of the TCRG gene. Use of the five BIOMED-2 TCRB and TCRG PCR multiplex tubes in parallel can detect approximately 94% of clonal TCR gene rearrangements.

  15. Study on cytokine modulation in mast cell-induced allergic reactions by using gamma-irradiated natural herbal extracts

    International Nuclear Information System (INIS)

    Gwon, Hui Jeong; Lim, Youn Mook; Kim, Yong Soo; Nho, Young Chang; Kim Hae Kyoung

    2009-01-01

    We previously described that some natural herbal extracts such as Houttuynia cordata (H), Centella asiatica (C), Plantago asiatica (P), Morus alba L. (M), and Ulmus davidiana (U), differentially suppress an atopic dermatitis like skin lesions. The objective of this study was to evaluate the pro-inflammatory cytokine modulation of the water extract of the H, C, P, M, U, and those mixtures (M) and their mechanism in a phorbol myristate acetate (PMA) plus calcium inopore A23187 treated human mast cell line (HMC-1). The H, C, P, M, U, and M inhibited the inflammatory cytokines such as TNF-α, IL-6 and IL-8 stimulated by PMA plus A23187 from HMC-1 cells. In addition, the M did not significantly affect the cell viability and had no toxicity on the HMC-1 cells. Based on these results, M can be used for the treatment of an allergic inflammation response

  16. Study on cytokine modulation in mast cell-induced allergic reactions by using gamma-irradiated natural herbal extracts

    Energy Technology Data Exchange (ETDEWEB)

    Gwon, Hui Jeong; Lim, Youn Mook; Kim, Yong Soo; Nho, Young Chang [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Kim Hae Kyoung [Chonbuk National University, Jeonju (Korea, Republic of)

    2009-12-15

    We previously described that some natural herbal extracts such as Houttuynia cordata (H), Centella asiatica (C), Plantago asiatica (P), Morus alba L. (M), and Ulmus davidiana (U), differentially suppress an atopic dermatitis like skin lesions. The objective of this study was to evaluate the pro-inflammatory cytokine modulation of the water extract of the H, C, P, M, U, and those mixtures (M) and their mechanism in a phorbol myristate acetate (PMA) plus calcium inopore A23187 treated human mast cell line (HMC-1). The H, C, P, M, U, and M inhibited the inflammatory cytokines such as TNF-{alpha}, IL-6 and IL-8 stimulated by PMA plus A23187 from HMC-1 cells. In addition, the M did not significantly affect the cell viability and had no toxicity on the HMC-1 cells. Based on these results, M can be used for the treatment of an allergic inflammation response.

  17. Direct methanol fuel cell with extended reaction zone anode: PtRu and PtRuMo supported on graphite felt

    Science.gov (United States)

    Bauer, Alex; Gyenge, Előd L.; Oloman, Colin W.

    Pressed graphite felt (thickness ∼350 μm) with electrodeposited PtRu (43 g m -2, 1.4:1 atomic ratio) or PtRuMo (52 g m -2, 1:1:0.3 atomic ratio) nanoparticle catalysts was investigated as an anode for direct methanol fuel cells. At temperatures above 333 K the fuel cell performance of the PtRuMo catalyst was superior compared to PtRu. The power density was 2200 W m -2 with PtRuMo at 5500 A m -2 and 353 K while under the same conditions PtRu yielded 1925 W m -2. However, the degradation rate of the Mo containing catalyst formulation was higher. Compared to conventional gas diffusion electrodes with comparable PtRu catalyst composition and load, the graphite felt anodes gave higher power densities mainly due to the extended reaction zone for methanol oxidation.

  18. New process of the preparation of catalyzed gas diffusion electrode for PEM fuel cells based on ultrasonic direct solution spray reaction method

    Energy Technology Data Exchange (ETDEWEB)

    Oishi, K.; Savadogo, O. [Ecole Polytechnique de Montreal, Montreal, PQ (Canada). Laboratoire de nouveaux materiaux pour l' energie et l' electrochimie

    2008-07-01

    This paper reported on a newly developed process for in-situ catalyst deposition on gas diffusion electrodes (GDE) for polymer electrolyte fuel cells. This process has the potential to reduce the number of steps for catalyzed GDE fabrication. In addition, the process offers economic advantages for the fuel cell commercialization. In this study, a home-made catalyst maker with ultrasonic spray method was used to prepare a solution of the carbon supported platinum catalyst on the GDL. The sprayed catalyst powder consisted of carbon support. The catalyst particles did not prevent gas flow channels on the GDL. The catalyst layer was shown to be located only on the top surface of the GDL and was not packed into its flow channel. Results of Cross-section SEM image, crystallization, micro structure and electro-catalytic activity for the oxygen reduction reaction were also discussed. 1 ref., 1 fig.

  19. Linear-after-the-exponential polymerase chain reaction and allied technologies. Real-time detection strategies for rapid, reliable diagnosis from single cells.

    Science.gov (United States)

    Pierce, Kenneth E; Wangh, Lawrence J

    2007-01-01

    Accurate detection of gene sequences in single cells is the ultimate challenge to polymerase chain reaction (PCR) sensitivity. Unfortunately, commonly used conventional and real-time PCR techniques are often too unreliable at that level to provide the accuracy needed for clinical diagnosis. Here we provide details of linear-after-the-exponential-PCR (LATE-PCR), a method similar to asymmetric PCR in the use of primers at different concentrations, but with novel design criteria to ensure high efficiency and specificity. Compared with conventional PCR, LATE-PCR increases the signal strength and allele discrimination capability of oligonucleotide probes such as molecular beacons and reduces variability among replicate samples. The analysis of real-time kinetics of LATE-PCR signals provides a means for improving the accuracy of single cell genetic diagnosis.

  20. Nitrogen and sulfur co-doped porous carbon – is an efficient electrocatalyst as platinum or a hoax for oxygen reduction reaction in acidic environment PEM fuel cell?

    International Nuclear Information System (INIS)

    Sahoo, Madhumita; Ramaprabhu, S.

    2017-01-01

    Non-precious, heteroatom doped carbon is reported to replace commercial Pt/C in both alkaline and acidic half-cell rotating disc electrode study; however the real world full cell measurements with the metal-free electrocatalysts overcoming the practical troubles in acidic environment proton exchange membrane fuel cell (PEMFC) are almost negligible to confirm the claim. Nitrogen and sulfur co-doped porous carbon (DPC) was synthesized in a one step, high yield process from single source ionic liquid precursor using eutectic salt as porogens to achieve porosity. Structural characterization confirms 7.03% nitrogen and 1.68% sulfur doping into the high surface area, porous carbon structure. As the cathode oxygen reduction reaction (ORR) catalyst, metal-free DPC and Pt nanoparticles decorated DPC (Pt/DPC) shows stable and high exchange current density by four electron transfer pathway in acidic half–cell liquid environment due to the synergistic effect of nitrogen and sulfur doping and porous nature of DPC. In an actual solid state full cell measurement, Pt/DPC shows higher performance comparable to commercial Pt/C; however DPC failed to reciprocate the half-cell performance due to blockage of active sites in the membrane electrode assembly fabrication process. - Highlights: • Synthesis of N and S co-doped porous carbon (DPC) in simple one-pot technique. • High surface area DPC shows comparable activity for ORR in half-cell acidic PEMFC study. • Real-world performance of DPC gives 20 mW/cm 2 peak power density at 60 °C. • Homogeneous Pt nanoparticles decorated DPC (Pt/DPC) outperforms commercial Pt/C. • Pt/DPC shows maximum power density of 718 mW/cm 2 with lower 0.3 mg/cm 2 total Pt loading.

  1. Experimental and modeling study of high performance direct carbon solid oxide fuel cell with in situ catalytic steam-carbon gasification reaction

    Science.gov (United States)

    Xu, Haoran; Chen, Bin; Zhang, Houcheng; Tan, Peng; Yang, Guangming; Irvine, John T. S.; Ni, Meng

    2018-04-01

    In this paper, 2D models for direct carbon solid oxide fuel cells (DC-SOFCs) with in situ catalytic steam-carbon gasification reaction are developed. The simulation results are found to be in good agreement with experimental data. The performance of DC-SOFCs with and without catalyst are compared at different operating potential, anode inlet gas flow rate and operating temperature. It is found that adding suitable catalyst can significantly speed up the in situ steam-carbon gasification reaction and improve the performance of DC-SOFC with H2O as gasification agent. The potential of syngas and electricity co-generation from the fuel cell is also evaluated, where the composition of H2 and CO in syngas can be adjusted by controlling the anode inlet gas flow rate. In addition, the performance DC-SOFCs and the percentage of fuel in the outlet gas are both increased with increasing operating temperature. At a reduced temperature (below 800 °C), good performance of DC-SOFC can still be obtained with in-situ catalytic carbon gasification by steam. The results of this study form a solid foundation to understand the important effect of catalyst and related operating conditions on H2O-assisted DC-SOFCs.

  2. Influence of Micropore and Mesoporous in Activated Carbon Air-cathode Catalysts on Oxygen Reduction Reaction in Microbial Fuel Cells

    International Nuclear Information System (INIS)

    Liu, Yi; Li, Kexun; Ge, Baochao; Pu, Liangtao; Liu, Ziqi

    2016-01-01

    In this study, carbon samples with different micropore and mesoporous structures are prepared as air-cathode catalyst layer to explore the role of pore structure on oxygen reduction reaction. The results of linear sweep voltammetry and power density show that the commercially-produced activated carbon (CAC) has the best electrochemical performance, and carbon samples with only micropore or mesoporous show lower performance than CAC. Nitrogen adsorption-desorption isotherms analysis confirm that CAC has highest surface area (1616 m 2 g −1 ) and a certain amount of micropore and mesoporous. According to Tafel plot and rotating disk electrode, CAC behaves the highest kinetic activity and electron transfer number, leading to the improvement of oxygen reduction reaction. The air permeability test proves that mesoporous structure enhance oxygen permeation. Carbon materials are also analyzed by In situ Fourier Transform Infrared Spectroscopy and H 2 temperature programmed reduction, which indicate that micropore provide active sites for catalysis. In a word, micropore and mesoporous together would improve the electrochemical performance of carbon materials.

  3. Condensed Matter Cluster Reactions in LENR Power Cells for a Radical New Type of Space Power Source

    Science.gov (United States)

    Yang, Xiaoling; Miley, George H.; Hora, Heinz

    2009-03-01

    This paper reviews previous theoretical and experimental study on the possibility of nuclear events in multilayer thin film electrodes (Lipson et al., 2004 and 2005; Miley et al., 2007), including the correlation between excess heat and transmutations (Miley and Shrestha, 2003) and the cluster theory that predicts it. As a result of this added understanding of cluster reactions, a new class of electrodes is under development at the University of Illinois. These electrodes are designed to enhance cluster formation and subsequent reactions. Two approaches are under development. The first employs improved loading-unloading techniques, intending to obtain a higher volumetric density of sites favoring cluster formation. The second is designed to create nanostructures on the electrode where the cluster state is formed by electroless deposition of palladium on nickel micro structures. Power units employing these electrodes should offer unique advantages for space applications. This is a fundamental new nuclear energy source that is environmentally compatible with a minimum of radiation involvement, high specific power, very long lifetime, and scalable from micro power to kilowatts.

  4. Condensed Matter Cluster Reactions in LENR Power Cells for a Radical New Type of Space Power Source

    International Nuclear Information System (INIS)

    Yang Xiaoling; Miley, George H.; Hora, Heinz

    2009-01-01

    This paper reviews previous theoretical and experimental study on the possibility of nuclear events in multilayer thin film electrodes (Lipson et al., 2004 and 2005; Miley et al., 2007), including the correlation between excess heat and transmutations (Miley and Shrestha, 2003) and the cluster theory that predicts it. As a result of this added understanding of cluster reactions, a new class of electrodes is under development at the University of Illinois. These electrodes are designed to enhance cluster formation and subsequent reactions. Two approaches are under development. The first employs improved loading-unloading techniques, intending to obtain a higher volumetric density of sites favoring cluster formation. The second is designed to create nanostructures on the electrode where the cluster state is formed by electroless deposition of palladium on nickel micro structures. Power units employing these electrodes should offer unique advantages for space applications. This is a fundamental new nuclear energy source that is environmentally compatible with a minimum of radiation involvement, high specific power, very long lifetime, and scalable from micro power to kilowatts.

  5. A CFD analysis of transport phenomena and electrochemical reactions in a tubular-shaped PEM fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Sadiq Al-Baghdadi, Maher A.R. [Fuel Cell Research Center, International Energy and Environment Foundation, Al-Najaf, P.O.Box 39 (Iraq)

    2013-07-01

    A fuel cell is most interesting new power source because it solves not only the environment problem but also natural resource exhaustion problem. CFD modeling and simulation for heat and mass transport in PEM fuel cells are being used extensively in researches and industrial applications to gain better understanding of the fundamental processes and to optimize fuel cell designs before building a prototype for engineering application. In this research, full three-dimensional, non-isothermal computational fluid dynamics model of a tubular-shaped proton exchange membrane (PEM) fuel cell has been developed. This comprehensive model accounts for the major transport phenomena such as convective and diffusive heat and mass transfer, electrode kinetics, transport and phase-change mechanism of water, and potential fields in a tubular-shaped PEM fuel cell. The model explains many interacting, complex electrochemical, and transport phenomena that cannot be studied experimentally. Three-dimensional results of the species profiles, temperature distribution, potential distribution, and local current density distribution are presented and analysed, with the focus on the physical insight and fundamental understanding.

  6. Characterization of mutations and loss of heterozygosity of p53 and K-ras2 in pancreatic cancer cell lines by immobilized polymerase chain reaction

    Directory of Open Access Journals (Sweden)

    Edwards Jeremy

    2003-07-01

    Full Text Available Abstract Background The identification of known mutations in a cell population is important for clinical applications and basic cancer research. In this work an immobilized form of the polymerase chain reaction, referred to as polony technology, was used to detect mutations as well as gene deletions, resulting in loss of heterozygosity (LOH, in cancer cell lines. Specifically, the mutational hotspots in p53, namely codons 175, 245, 248, 249, 273, and 282, and K-ras2, codons 12, 13 and 61, were genotyped in the pancreatic cell line, Panc-1. In addition LOH analysis was also performed for these same two genes in Panc-1 by quantifying the relative gene copy number of p53 and K-ras2. Results Using polony technology, Panc-1 was determined to possess only one copy of p53, which possessed a mutation in codon 273, and two copies of K-ras2, one wildtype and one with a mutation in codon 12. To further demonstrate the general approach of this method, polonies were also used to detect K-ras2 mutations in the pancreatic cell lines, AsPc-1 and CAPAN-1. Conclusions In conclusion, we have developed an assay that can detect mutations in hotspots of p53 and K-ras2 as well as diagnose LOH in these same genes.

  7. Reaction-based small-molecule fluorescent probes for dynamic detection of ROS and transient redox changes in living cells and small animals.

    Science.gov (United States)

    Lü, Rui

    2017-09-01

    Dynamic detection of transient redox changes in living cells and animals has broad implications for human health and disease diagnosis, because intracellular redox homeostasis regulated by reactive oxygen species (ROS) plays important role in cell functions, normal physiological functions and some serious human diseases (e.g., cancer, Alzheimer's disease, diabetes, etc.) usually have close relationship with the intracellular redox status. Small-molecule ROS-responsive fluorescent probes can act as powerful tools for dynamic detection of ROS and redox changes in living cells and animals through fluorescence imaging techniques; and great advances have been achieved recently in the design and synthesis of small-molecule ROS-responsive fluorescent probes. This article highlights up-to-date achievements in designing and using the reaction-based small-molecule fluorescent probes (with high sensitivity and selectivity to ROS and redox cycles) in the dynamic detection of ROS and transient redox changes in living cells and animals through fluorescence imaging. Copyright © 2017. Published by Elsevier Ltd.

  8. Live-Cell MicroRNA Imaging through MnO2 Nanosheet-Mediated DD-A Hybridization Chain Reaction.

    Science.gov (United States)

    Ou, Min; Huang, Jin; Yang, Xiaohai; He, Xiaoxiao; Quan, Ke; Yang, Yanjing; Xie, Nuli; Li, Jing; Wang, Kemin

    2018-01-18

    Innovative techniques to visualize native microRNAs (miRNAs) in live cells can dramatically impact current research on the roles of miRNA in biology and medicine. Here, we report a novel approach for live-cell miRNA imaging using a biodegradable MnO 2 nanosheet-mediated DD-A FRET hybridization chain reaction (HCR). The MnO 2 nanosheets can adsorb DNA hairpin probes and deliver them into live cells. After entering cells, the MnO 2 nanosheets are degraded by cellular GSH. Then, the target miR-21 triggers cascaded assembly of the liberated hairpin probes into long dsDNA polymers, which brings each two FAMs (donor) and one TAMRA (acceptor) into close proximity to generate significantly enhanced DD-A FRET signals, which was discovered and proven by our previous report. We think the developed approach can serve as an excellent intracellular miRNAs detection tool, which promises the potential for biological and disease studies. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Rapid assessment of repair of ultraviolet DNA damage with a modified host-cell reactivation assay using a luciferase reporter gene and correlation with polymorphisms of DNA repair genes in normal human lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Qiao Yawei; Spitz, Margaret R.; Guo Zhaozheng; Hadeyati, Mohammad; Grossman, Lawrence; Kraemer, Kenneth H.; Wei Qingyi

    2002-11-30

    As DNA repair plays an important role in genetic susceptibility to cancer, assessment of the DNA repair phenotype is critical for molecular epidemiological studies of cancer. In this report, we compared use of the luciferase (luc) reporter gene in a host-cell reactivation (HCR) (LUC) assay of repair of ultraviolet (UV) damage to DNA to use of the chloramphenicol (cat) gene-based HCR (CAT) assay we used previously for case-control studies. We performed both the assays on cryopreserved lymphocytes from 102 healthy non-Hispanic white subjects. There was a close correlation between DNA repair capacity (DRC) as measured by the LUC and CAT assays. Although these two assays had similar variation, the LUC assay was faster and more sensitive. We also analyzed the relationship between DRC and the subjects' previously determined genotypes for four polymorphisms of two nucleotide-excision repair (NER) genes (in intron 9 of xeroderma pigmentosum (XP) C and exons 6, 10 and 23 of XPD) and one polymorphism of a base-excision repair gene in exon 10 of X-ray complementing group 1 (XRCC1). The DRC was significantly lower in subjects homozygous for one or more polymorphisms of the two NER genes than in subjects with other genotypes (P=0.010). In contrast, the polymorphic XRCC1 allele had no significant effect on DRC. These results suggest that the post-UV LUC assay measures NER phenotype and that polymorphisms of XPC and XPD genes modulate DRC. For population studies of the DNA repair phenotype, many samples need to be evaluated, and so the LUC assay has several advantages over the CAT assay: the LUC assay was more sensitive, had less variation, was not radioactive, was easier to perform, and required fewer cryopreserved cells. These features make the LUC-based HCR assay suitable for molecular epidemiological studies.

  10. Highly sensitive KRAS mutation detection from formalin-fixed paraffin-embedded biopsies and circulating tumour cells using wild-type blocking polymerase chain reaction and Sanger sequencing.

    Science.gov (United States)

    Huang, Meggie Mo Chao; Leong, Sai Mun; Chua, Hui Wen; Tucker, Steven; Cheong, Wai Chye; Chiu, Lily; Li, Mo-Huang; Koay, Evelyn Siew-Chuan

    2014-08-01

    Among patients with colorectal cancer (CRC), KRAS mutations were reported to occur in 30-51 % of all cases. CRC patients with KRAS mutations were reported to be non-responsive to anti-epidermal growth factor receptor (EGFR) monoclonal antibody (MoAb) treatment in many clinical trials. Hence, accurate detection of KRAS mutations would be critical in guiding the use of anti-EGFR MoAb therapies in CRC. In this study, we carried out a detailed investigation of the efficacy of a wild-type (WT) blocking real-time polymerase chain reaction (PCR), employing WT KRAS locked nucleic acid blockers, and Sanger sequencing, for KRAS mutation detection in rare cells. Analyses were first conducted on cell lines to optimize the assay protocol which was subsequently applied to peripheral blood and tissue samples from patients with CRC. The optimized assay provided a superior sensitivity enabling detection of as little as two cells with mutated KRAS in the background of 10(4) WT cells (0.02 %). The feasibility of this assay was further investigated to assess the KRAS status of 45 colorectal tissue samples, which had been tested previously, using a conventional PCR sequencing approach. The analysis showed a mutational discordance between these two methods in 4 of 18 WT cases. Our results present a simple, effective, and robust method for KRAS mutation detection in both paraffin embedded tissues and circulating tumour cells, at single-cell level. The method greatly enhances the detection sensitivity and alleviates the need of exhaustively removing co-enriched contaminating lymphocytes.

  11. Effect of X-ray irradiation on morphophysiological reactions of epidermal melanophor cells in the larvae of Rana temporaria L

    International Nuclear Information System (INIS)

    Popov, D.V.; Kalistratova, E.N.; Kaluzhina, A.V.

    1982-01-01

    Dynamics of physiological reactions of epidermal melanophors of larvae Rana temporaria L.. adapted to white and black backgrounds and irradiated with a dose of 700 R has been investigated. Ouring the first day after irradiation no day changes of melanophor index characteristic of intact tadpoles were discovered in whitebackground animals; melanophors preserve the aggregation state. Comparison of black background irradiated and control larvae didn't show confident differences in changes of their melanophor indices. Irradiation affects differently epidermal melanophors in the state of pigment dispersion and aggregation. It is suggested that pigment dispersion and aggregation in melanophor is realized at the expense of different cellular structures. It is shown that by the end of the experiment (21-st day) the amount of epidermal melanophor per surface unit is two times larger in black-ground larvae. General biological signaficance of revealed facts from the point of view of ontogenesis evolution is discussed

  12. Mechanistic investigation and modelling of anode reaction in the molten carbonate fuel cell; Mechanistische Untersuchung und Modellierung der Anodenreaktion in der Karbonat-Brennstoffzelle

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Markus Roman

    2011-04-27

    Considering distributed energy generation, molten carbonate fuel cells (MCFCs) have best prospects to fulfil the demands of the highly competing energy market. To establish MCFC technology in the market, various requirements need to be met. These are on the one hand the reduction of the specific costs per kW and the simultaneous increase in efficiency of the MCFCs. On the other hand, an extended lifetime of MCFC stacks in general and especially when biofuels are used is required. Detailed knowledge of electrodes' reaction mechanisms is essential for successful technical improvements or cost reduction measures. In this thesis, the complex anodic reaction mechanism in the molten carbonate fuel cell is studied in detail, with the objective to develop a fundamental understanding of the physical and electrochemical processes taking place at the anode, and to identify the factors influencing the performance of fuel cell stacks. These include a detailed study of the simultaneously performed oxidation reactions of hydrogen and carbon monoxide and its kinetic parameters, the detailed analysis of mass transport, adsorption and charge transfer and the observation of degradation phenomena, which have a declining effect on cell performance and lifetime. In order to gain this knowledge, several testing facilities have been used: anode half-cells and single cells. Electrochemical impedance spectroscopy (EIS) has been applied as analyzing tool for physical and electrochemical phenomena, whose results have been integrated in the development of an equivalent circuit. Linking the elements of the equivalent circuit with physical process parameters has been done by using a numerical model for the MCFC-anode. The impedance measurements of the MCFC anodes result in four characteristic resistances: ohmic resistance, high-frequency resistance, low-frequency resistance and cumulative resistance. The strongly temperature dependent high-frequency resistance is influenced by the electrode

  13. Quasielastic reactions

    International Nuclear Information System (INIS)

    Henning, W.

    1979-01-01

    Quasielastic reaction studies, because of their capability to microscopically probe nuclear structure, are still of considerable interest in heavy-ion reactions. The recent progress in understanding various aspects of the reaction mechanism make this aim appear closer. The relation between microscopic and macroscopic behavior, as suggested, for example, by the single proton transfer data to individual final states or averaged excitation energy intervals, needs to be explored. It seems particularly useful to extend measurements to higher incident energies, to explore and understand nuclear structure aspects up to the limit of the energy range where they are important

  14. Severe type 1 upgrading leprosy reaction in a renal transplant recipient: a paradoxical manifestation associated with deficiency of antigen-specific regulatory T-cells?

    Science.gov (United States)

    Vieira, Ana Paula; Trindade, Maria Angela Bianconcini; de Paula, Flávio Jota; Sakai-Valente, Neusa Yurico; Duarte, Alberto José da Silva; Lemos, Francine Brambate Carvalhinho; Benard, Gil

    2017-04-24

    Due to its chronic subclinical course and large spectrum of manifestations, leprosy often represents a diagnostic challenge. Even with proper anti-mycobacteria treatment, leprosy follow up remains challenging: almost half of leprosy patients may develop reaction episodes. Leprosy is an infrequent complication of solid organ transplant recipients. This case report illustrates the challenges in diagnosing and managing leprosy and its reactional states in a transplant recipient. A 53-year-old man presented 34 months after a successful renal transplantation a borderline-tuberculoid leprosy with signs of mild type 1 upgrading reaction (T1R). Cutaneous manifestations were atypical, and diagnosis was only made when granulomatous neuritis was found in a cutaneous biopsy. He was successfully treated with the WHO recommended multidrug therapy (MDT: rifampicin, dapsone and clofazimine). However he developed a severe T1R immediately after completion of the MDT but no signs of allograft rejection. T1R results from flare-ups of the host T-helper-1 cell-mediated immune response against Mycobacterium leprae antigens in patients with immunologically unstable, borderline forms of leprosy and has been considered an inflammatory syndrome in many aspects similar to the immune reconstitution inflammatory syndromes (IRS). The T1R was successfully treated by increasing the prednisone dose without modifying the other immunosuppressive drugs used for preventing allograft rejection. Immunological study revealed that the patient had a profound depletion of both in situ and circulating regulatory T-cells and lack of expansion of the Tregs upon M. leprae stimulation compared to T1R leprosy patients without iatrogenic immunosuppression. Our case report highlights that leprosy, especially in the transplant setting, requires a high degree of clinical suspicion and the contribution of histopathology. It also suggests that the development of upgrading inflammatory syndromes such as T1R can occur

  15. cycloaddition reactions

    Indian Academy of Sciences (India)

    Unknown

    Molecular Modeling Group, Organic Chemical Sciences, Indian Institute of Chemical Technology,. Hyderabad ... thus obtained are helpful to model the regioselectivity ... compromise to model Diels–Alder reactions involving ...... acceptance.

  16. Nb-doped TiO2 cathode catalysts for oxygen reduction reaction of polymer electrolyte fuel cells

    KAUST Repository

    Arashi, Takuya

    2014-09-01

    Nb-doped TiO2 particles were studied as electrocatalysts for the oxygen reduction reaction (ORR) under acidic conditions. The Nb-doped TiN nanoparticles were first synthesized by meso-porous C3N4 and then fully oxidized to Nb-doped TiO2 by immersing in 0.1 M H 2SO4 at 353 K for 24 h. Although the ORR activity of the as-obtained sample was low, a H2 treatment at relatively high temperature (1173 K) dramatically improved the ORR performance. An onset potential as high as 0.82 VRHE was measured. No degradation of the catalysts was observed during the oxidation-reduction cycles under the ORR condition for over 127 h. H2 treatment at temperatures above 1173 K caused the formation of a Ti4O7 phase, resulting in a decrease in ORR current. Elemental analysis indicated that the Nb-doped TiO 2 contained 25 wt% residual carbon. Calcination in air at 673 or 973 K eliminated the residual carbon in the catalyst, which was accompanied by a dramatic decrease in ORR activity. This post-calcination process may reduce the conductivity of the sample by filling the oxygen vacancies, and the carbon residue in the particle aggregates may enhance the electrocatalytic activity for ORR. The feasibility of using conductive oxide materials as electrocatalysts is discussed. © 2013 Elsevier B.V.

  17. Reduction of Powerplex(®) Y23 reaction volume for genotyping buccal cell samples on FTA(TM) cards.

    Science.gov (United States)

    Raziel, Aliza; Dell'Ariccia-Carmon, Aviva; Zamir, Ashira

    2015-01-01

    PowerPlex(®) Y23 is a novel kit for Y-STR typing that includes new highly discriminating loci. The Israel DNA Database laboratory has recently adopted it for routine Y-STR analysis. This study examined PCR amplification from 1.2-mm FTA punch in reduced volumes of 5 and 10 μL. Direct amplification and washing of the FTA punches were examined in different PCR cycle numbers. One short robotically performed wash was found to improve the quality and the percent of profiles obtained. The optimal PCR cycle number was determined for 5 and 10 μL reaction volumes. The percent of obtained profiles, color balance, and reproducibility were examined. High-quality profiles were achieved in 90% and 88% of the samples amplified in 5 and 10 μL, respectively, in the first attempt. Volume reduction to 5 μL has a vast economic impact especially for DNA database laboratories. © 2014 American Academy of Forensic Sciences.

  18. Nb-doped TiO2 cathode catalysts for oxygen reduction reaction of polymer electrolyte fuel cells

    KAUST Repository

    Arashi, Takuya; Seo, Jeongsuk; Takanabe, Kazuhiro; Kubota, Jun; Domen, Kazunari

    2014-01-01

    Nb-doped TiO2 particles were studied as electrocatalysts for the oxygen reduction reaction (ORR) under acidic conditions. The Nb-doped TiN nanoparticles were first synthesized by meso-porous C3N4 and then fully oxidized to Nb-doped TiO2 by immersing in 0.1 M H 2SO4 at 353 K for 24 h. Although the ORR activity of the as-obtained sample was low, a H2 treatment at relatively high temperature (1173 K) dramatically improved the ORR performance. An onset potential as high as 0.82 VRHE was measured. No degradation of the catalysts was observed during the oxidation-reduction cycles under the ORR condition for over 127 h. H2 treatment at temperatures above 1173 K caused the formation of a Ti4O7 phase, resulting in a decrease in ORR current. Elemental analysis indicated that the Nb-doped TiO 2 contained 25 wt% residual carbon. Calcination in air at 673 or 973 K eliminated the residual carbon in the catalyst, which was accompanied by a dramatic decrease in ORR activity. This post-calcination process may reduce the conductivity of the sample by filling the oxygen vacancies, and the carbon residue in the particle aggregates may enhance the electrocatalytic activity for ORR. The feasibility of using conductive oxide materials as electrocatalysts is discussed. © 2013 Elsevier B.V.

  19. Electrochemical formation of a Pt/Zn alloy and its use as a catalyst for oxygen reduction reaction in fuel cells.

    Science.gov (United States)

    Sode, Aya; Li, Winton; Yang, Yanguo; Wong, Phillip C; Gyenge, Elod; Mitchell, Keith A R; Bizzotto, Dan

    2006-05-04

    The characterization of an electrochemically created Pt/Zn alloy by Auger electron spectroscopy is presented indicating the formation of the alloy, the oxidation of the alloy, and the room temperature diffusion of the Zn into the Pt regions. The Pt/Zn alloy is stable up to 1.2 V/RHE and can only be removed with the oxidation of the base Pt metal either electrochemically or in aqua regia. The Pt/Zn alloy was tested for its effectiveness toward oxygen reduction. Kinetics of the oxygen reduction reaction (ORR) were measured using a rotating disk electrode (RDE), and a 30 mV anodic shift in the potential of ORR was found when comparing the Pt/Zn alloy to Pt. The Tafel slope was slightly smaller than that measured for the pure Pt electrode. A simple procedure for electrochemically modifying a Pt-containing gas diffusion electrode (GDE) with Zn was developed. The Zn-treated GDE was pressed with an untreated GDE anode, and the created membrane electrode assembly was tested. Fuel cell testing under two operating conditions (similar anode and cathode inlet pressures, and a larger cathode inlet pressure) indicated that the 30 mV shift observed on the RDE was also evident in the fuel cell tests. The high stability of the Pt/Zn alloy in acidic environments has a potential benefit for fuel cell applications.

  20. Effect of sodium acetate additive in successive ionic layer adsorption and reaction on the performance of CdS quantum-dot-sensitized solar cells

    Science.gov (United States)

    Liu, I.-Ping; Chen, Liang-Yih; Lee, Yuh-Lang

    2016-09-01

    Sodium acetate (NaAc) is utilized as an additive in cationic precursors of the successive ionic layer adsorption and reaction (SILAR) process to fabricate CdS quantum-dot (QD)-sensitized photoelectrodes. The effects of the NaAc concentration on the deposition rate and distribution of QDs in mesoporous TiO2 films, as well as on the performance of CdS-sensitized solar cells are studied. The experimental results show that the presence of NaAc can significantly accelerate the deposition of CdS, improve the QD distribution across photoelectrodes, and thereby, increase the performance of solar cells. These results are mainly attributed to the pH-elevation effect of NaAc to the cationic precursors which increases the electrostatic interaction of the TiO2 film to cadmium ions. The light-to-energy conversion efficiency of the CdS-sensitized solar cell increases with increasing concentration of the NaAc and approaches a maximum value (3.11%) at 0.05 M NaAc. Additionally, an ionic exchange is carried out on the photoelectrode to transform the deposited CdS into CdS1-xSex ternary QDs. The light-absorption range of the photoelectrode is extended and an exceptional power conversion efficiency of 4.51% is achieved due to this treatment.

  1. Comparison of hybrid capture and reverse transcriptase polymerase chain reaction methods in terms of diagnosing human cytomegalovirus infection in patients following hematopoietic stem cell transplantation

    International Nuclear Information System (INIS)

    Orsal, Arif S.; Ozsan, M.; Dolapci, I.; Tekeli, A.; Becksac, M.

    2006-01-01

    Human cytomegalovirus (CMV) is a life threatening cause of infection among hematopoietic stem cell recipients. Developing reliable methods in detecting the CMV infection is important to identify the patients at risk of CMV infection and disease. The aim of this study was to compare the 2 tests- hybrid capture test, which is routinely used in the diagnosis of CMV infection among hematopoietic stem cell recipients, and reverse transcriptase polymerase chain reaction (RT-PCR) detecting UL21.5 mRNA transcripts of the active virus. In this prospective study, a total of 178 blood samples obtained 35 patients following allogeneic hematopoietic stem cell transplantation at the Bone Marrow Transplantation Unit of the Hematology Department, Ibn-i-Sina Hospital of Ankara University School of Medicine, Turkey between January 2003 and September 2003 were analyzed. Hybrid capture and RT-PCR using UL21.5 gene transcript method to investigate HCMV in blood samples were performed at the department of Microbiology and Clinic Microbiology, Ankara University School of Medicine, Turkey. When Hybrid capture test was accepted as the golden standard, the sensitivity of Rt-PCR was 3%, specificity 100%, false negativity 67%, false positivity 0%, positive predictive value 100%, negative predictive value 74%, and accuracy was 77%. Improving this test by quantification, and application of additional gene transcripts, primarily the late gene transcripts can help increase the sensitivity and feasibility. (author)

  2. Au-MnO{sub 2}/MWNT and Au-ZnO/MWNT as oxygen reduction reaction electrocatalyst for polymer electrolyte membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Imran Jafri, Razack; Sujatha, N.; Ramaprabhu, S. [Alternative Energy and Nanotechnology Laboratory (AENL), Nano Functional Materials Technology Centre (NFMTC), Department of Physics, Indian Institute of Technology Madras, Chennai (India); Rajalakshmi, N. [Center for Fuel Cell Technology (ARCI), Madavakkam, Chennai (India)

    2009-08-15

    Bi-functional catalysts based on Au supported on oxide based nanomaterials for use in fuel cells were evaluated by electrochemical methods for oxygen reduction reaction (ORR) in Polymer Electrolyte Membrane Fuel Cell (PEMFC). Metal oxide coated multi walled carbon nanotubes (MWNTs) (MnO{sub 2}/MWNT and ZnO/MWNT) were prepared by reduction of potassium permanganate and oxidation of Zn powder on MWNT surface respectively. Au-MnO{sub 2}/MWNT and Au-ZnO/MWNT were prepared by chemical reduction of chloroauric acid on MnO{sub 2}/MWNT and ZnO/MWNT. The samples were characterized and linear sweep voltammetric studies were performed in N{sub 2} saturated, O{sub 2} saturated and methanol containing 1 M KOH solution and the results have been discussed. A single fuel cell was also constructed using Au-MnO{sub 2}/MWNT and Au-ZnO/MWNT as ORR electrocatalysts. A maximum power density of 45 mW/cm{sup 2} and 56 mW/cm{sup 2} was obtained with Au-MnO{sub 2}/MWNT and Au-ZnO/MWNT respectively. Additionally, the methanol tolerance of these electrocatalysts has been investigated and results have been discussed. (author)

  3. Study on lethal effect on cells by determination of 10B in biological tissues and (n, α) reaction

    International Nuclear Information System (INIS)

    Ishida, Masahiro; Tsuruta, Takao; Takagaki, Masao

    1980-01-01

    As for the macroscopic distribution in tissues and microscopic distribution in cells of 10 B administrated to patients, which are important in thermal neutron capture therapy, it is difficult to say that the method of quantitative determination has been established. The authors tried some experiments by solid state track detection for the determination. That is, the trial determinations of boron in cells by solution method (wet process), filter paper method (dry process) and the method using an electron microscope are reported. If the maximum thermal neutron fluence available is assumed to be 10 14 /cm 2 and the minimum detectable surface density of etch pits is 10 4 /cm 2 , the detection limit of 10 B concentration is estimated as about 10 -2 μg/ml either in the solution method or in the filter paper method. In the quantitative determination of boron distribution at cell level with an electron microscope, a sample of tissue was covered with a plastic thin film, etched after the irradiation with thermal neutrons, and the tissue and the thin film were simultaneously observed with the transmission electron microscope. The thin film thickness of about 0.1 μm is suitable for the sliced tissue of about 0.1 μm thick. The existence of fast neutrons at the time of thermal neutron irradiation causes the generation of etch pits by recoiled particles in celluloid, and increases background counts, while γ-dose above 10 6 rad leads to the deterioration of celluloid composition. Some automatic methods of counting etch pits under consideration are described. (Wakatsuki, Y.)

  4. Spillover effect induced Pt-TiO2/C as ethanol tolerant oxygen reduction reaction catalyst for direct ethanol fuel cells

    International Nuclear Information System (INIS)

    Meenakshi, S.; Nishanth, K.G.; Sridhar, P.; Pitchumani, S.

    2014-01-01

    Hypo-hyper-d-electronic interactive nature is used to develop a new carbon supported HT-Pt-TiO 2 composite catalyst comprising Pt and Ti in varying atomic ratio, namely 1:1, 2:1 and 3:1. The electro-catalysts are characterized by XRD, TEM, SEM-EDAX, Cyclic Voltammetry (CV) and Linear sweep voltammetry (LSV) techniques. HT-Pt-TiO 2 /C catalysts exhibit significant improvement in oxygen reduction reaction (ORR) over Pt/C. The effect of composition towards ORR with and without ethanol has been studied. The direct ethanol fuel cell (DEFC) with HT-Pt-TiO 2 /C cathode catalyst exhibits an enhanced peak power density of 41 mW cm −2 , whereas 21 mW cm −2 is obtained for the DEFCs with carbon-supported Pt catalyst operating under identical conditions

  5. Long-term effect of whole-body X-irradiation on cell-mediated immune reaction in mice

    International Nuclear Information System (INIS)

    Norimura, Toshiyuki; Tsuchiya, Takehiko

    1989-01-01

    Age-related change in immunological activity was examined at 10 to 91 weeks following whole-body irradiation by determining the specific anti-tumor cell-mediated immunity in host mice induced and/or enhanced by local irradiation to transplanted tumor. Median survival time of the non-irradiated C3H/He female mice was 98.6 weeks while the median life-span of the mice exposed to two and four Gy of 250 kVp X-rays at the age of 10-12 weeks was shortened by 14.9 and 23.4 weeks, respectively. The rate of tumor reduction within two weeks after local irradiation to tumor and the growth inhibitory activitiy of spleen cells from tumor irradiated mice were reduced in a dose-dependent manner when assessed 10 weeks after whole-body irradiation, but recovered to the near-complete level of the non-irradiated controls within a few months, then gradually decreased with normal aging. These results suggest that the age-dependent decline of this immunological activity apears earlier in the irradiated mice as a result of whole-body X-irradiation at a young age, suggesting accelerated aging of the immune system. (author)

  6. Modifying the 5'-Cap for Click Reactions of Eukaryotic mRNA and To Tune Translation Efficiency in Living Cells.

    Science.gov (United States)

    Holstein, Josephin M; Anhäuser, Lea; Rentmeister, Andrea

    2016-08-26

    The 5'-cap is a hallmark of eukaryotic mRNAs and plays fundamental roles in RNA metabolism, ranging from quality control to export and translation. Modifying the 5'-cap may thus enable modulation of the underlying processes and investigation or tuning of several biological functions. A straightforward approach is presented for the efficient production of a range of N7-modified caps based on the highly promiscuous methyltransferase Ecm1. We show that these, as well as N(2) -modified 5'-caps, can be used to tune translation of the respective mRNAs both in vitro and in cells. Appropriate modifications allow subsequent bioorthogonal chemistry, as demonstrated by intracellular live-cell labeling of a target mRNA. The efficient and versatile N7 manipulation of the mRNA cap makes mRNAs amenable to both modulation of their biological function and intracellular labeling, and represents a valuable addition to the chemical biology toolbox. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Soil pretreatment and fast cell lysis for direct polymerase chain reaction from forest soils for terminal restriction fragment length polymorphism analysis of fungal communities

    Directory of Open Access Journals (Sweden)

    Fei Cheng

    Full Text Available Abstract Humic substances in soil DNA samples can influence the assessment of microbial diversity and community composition. Using multiple steps during or after cell lysis adds expenses, is time-consuming, and causes DNA loss. A pretreatment of soil samples and a single step DNA extraction may improve experimental results. In order to optimize a protocol for obtaining high purity DNA from soil microbiota, five prewashing agents were compared in terms of their efficiency and effectiveness in removing soil contaminants. Residual contaminants were precipitated by adding 0.6 mL of 0.5 M CaCl2. Four cell lysis methods were applied to test their compatibility with the pretreatment (prewashing + Ca2+ flocculation and to ultimately identify the optimal cell lysis method for analyzing fungal communities in forest soils. The results showed that pretreatment with TNP + Triton X-100 + skim milk (100 mM Tris, 100 mM Na4P2O7, 1% polyvinylpyrrolidone, 100 mM NaCl, 0.05% Triton X-100, 4% skim milk, pH 10.0 removed most soil humic contaminants. When the pretreatment was combined with Ca2+ flocculation, the purity of all soil DNA samples was further improved. DNA samples obtained by the fast glass bead-beating method (MethodFGB had the highest purity. The resulting DNA was successfully used, without further purification steps, as a template for polymerase chain reaction targeting fungal internal transcribed spacer regions. The results obtained by terminal restriction fragment length polymorphism analysis indicated that the MethodFGB revealed greater fungal diversity and more distinctive community structure compared with the other methods tested. Our study provides a protocol for fungal cell lysis in soil, which is fast, convenient, and effective for analyzing fungal communities in forest soils.

  8. Direct Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Austern, N. [University of Pittsburgh, Pittsburgh, PA (United States)

    1963-01-15

    In order to give a unified presentation of one point of view, these lectures are devoted only to a detailed development of the standard theories of direct reactions, starting from basic principles. Discussion is given of the present status of the theories, of the techniques used for practical calculation, and of possible future developments. The direct interaction (DI) aspects of a reaction are those which involve only a few of the many degrees of freedom of a nucleus. In fact the minimum number of degrees of freedom which must be involved in a reaction are those required to describe the initial and final channels, and DI studies typically consider these degrees of freedom and no others. Because of this simplicity DI theories may be worked out in painstaking detail. DI processes concern only part of the wave function for a problem. The other part involves complicated excitations of many degrees of freedom, and gives the compound nucleus (CN) effects. While it is extremely interesting to learn how to separate DI and CN effects in an orderly manner, if they are both present in a reaction, no suitable method has yet been found. Instead, current work stresses the kinds of reactions and the kinds of final states in which DI effects dominate and in which CN effects may almost be forgotten. The DI cross-sections which are studied are often extremely large, comparable to elastic scattering cross-sections. (author)

  9. Reaction mechanisms

    International Nuclear Information System (INIS)

    Nguyen Trong Anh

    1988-01-01

    The 1988 progress report of the Reaction Mechanisms laboratory (Polytechnic School, France), is presented. The research topics are: the valence bond methods, the radical chemistry, the modelling of the transition states by applying geometric constraints, the long range interactions (ion - molecule) in gaseous phase, the reaction sites in gaseous phase and the mass spectroscopy applications. The points of convergence between the investigations of the mass spectroscopy and the theoretical chemistry teams, as well as the purposes guiding the research programs, are discussed. The published papers, the conferences, the congress communications and the thesis, are also reported [fr

  10. Unraveling the Role of Transport, Electrocatalysis, and Surface Science in the Solid Oxide Fuel Cell Cathode Oxygen Reduction Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Gopalan, Srikanth [Boston Univ., MA (United States)

    2017-04-06

    This final report for project FE0009656 covers the period from 10/01/2012 to 09/30/2015 and covers research accomplishments on the effects of carbon dioxide on the surface composition and structure of cathode materials for solid oxide fuel cells (SOFCs), specifically La1-xSrxFeyCo1- yO3-δ (LSCF). Epitaxially deposited thin films of LSCF on various single-crystal substrates have revealed the selective segregation of strontium to the surface thereby resulting in a surface enrichment of strontium. The near surface compositional profile in the films have been measured using total x-ray fluorescence (TXRF), and show that the kinetics of strontium segregation are higher at higher partial pressures of carbon dioxide. Once the strontium segregates to the surface, it leads to the formation of precipitates of SrO which convert to SrCO3 in the presence of even modest concentrations of carbon dioxide in the atmosphere. This has important implications for the performance of SOFCs which is discussed in this report. These experimental observations have also been verified by Density Functional Theory calculations (DFT) which predict the conditions under which SrO and SrCO3 can occur in LSCF. Furthermore, a few cathode compositions which have received attention in the literature as alternatives to LSCF cathodes have been studied in this work and shown to be thermodynamically unstable under the operating conditions of the SOFCs.

  11. Direct methanol fuel cell with extended reaction zone anode: PtRu and PtRuMo supported on graphite felt

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Alex; Gyenge, Elod L.; Oloman, Colin W. [Department of Chemical and Biological Engineering, The University of British Columbia, 2360 East Mall, Vancouver, BC (Canada)

    2007-05-15

    Pressed graphite felt (thickness {proportional_to}350 {mu}m) with electrodeposited PtRu (43 g m{sup -2}, 1.4:1 atomic ratio) or PtRuMo (52 g m{sup -2}, 1:1:0.3 atomic ratio) nanoparticle catalysts was investigated as an anode for direct methanol fuel cells. At temperatures above 333 K the fuel cell performance of the PtRuMo catalyst was superior compared to PtRu. The power density was 2200 W m{sup -2} with PtRuMo at 5500 A m{sup -2} and 353 K while under the same conditions PtRu yielded 1925 W m{sup -2}. However, the degradation rate of the Mo containing catalyst formulation was higher. Compared to conventional gas diffusion electrodes with comparable PtRu catalyst composition and load, the graphite felt anodes gave higher power densities mainly due to the extended reaction zone for methanol oxidation. (author)

  12. Effect of cationic molecules on the oxygen reduction reaction on fuel cell grade Pt/C (20 wt%) catalyst in potassium hydroxide (aq, 1 mol dm(-3)).

    Science.gov (United States)

    Ong, Ai Lien; Inglis, Kenneth K; Whelligan, Daniel K; Murphy, Sam; Varcoe, John R

    2015-05-14

    This study investigates the effect of 1 mmol dm(-3) concentrations of a selection of small cationic molecules on the performance of a fuel cell grade oxygen reduction reaction (ORR) catalyst (Johnson Matthey HiSPEC 3000, 20 mass% Pt/C) in aqueous KOH (1 mol dm(-3)). The cationic molecules studied include quaternary ammonium (including those based on bicyclic systems) and imidazolium types as well as a phosphonium example: these serve as fully solubilised models for the commonly encountered head-groups in alkaline anion-exchange membranes (AAEM) and anion-exchange ionomers (AEI) that are being developed for application in alkaline polymer electrolyte fuel cells (APEFCs), batteries and electrolysers. Both cyclic and hydrodynamic linear sweep rotating disk electrode voltammetry techniques were used. The resulting voltammograms and subsequently derived data (e.g. apparent electrochemical active surface areas, Tafel plots, and number of [reduction] electrons transferred per O2) were compared. The results show that the imidazolium examples produced the highest level of interference towards the ORR on the Pt/C catalyst under the experimental conditions used.

  13. Metal-free bioconjugation reactions.

    Science.gov (United States)

    van Berkel, Sander S; van Delft, Floris L

    2013-01-01

    The recent strategy to apply chemical reactions to address fundamental biological questions has led to the emergence of entirely new conjugation reactions that are fast and irreversible, yet so mild and selective that they can be performed even in living cells or organisms. These so-called bioorthogonal reactions open novel avenues, not only in chemical biology research, but also in many other life sciences applications, including the modulation of biopharmaceuticals by site-specific modification approaches.

  14. Oxidation Characteristics and Electrical Properties of Doped Mn-Co Spinel Reaction Layer for Solid Oxide Fuel Cell Metal Interconnects

    Directory of Open Access Journals (Sweden)

    Pingyi Guo

    2018-01-01

    Full Text Available To prevent Cr poisoning of the cathode and to retain high conductivity during solid oxide fuel cell (SOFC operation, Cu or La doped Co-Mn coatings on a metallic interconnect is deposited and followed by oxidation at 750 °C. Microstructure and composition of coatings after preparation and oxidation is analyzed by X-ray diffraction (XRD and scanning electron microscopy (SEM. High energy micro arc alloying process, a low cost technique, is used to prepare Cu or La doped Co-Mn coatings with the metallurgical bond. When coatings oxidized at 750 °C in air for 20 h and 100 h, Co3O4 is the main oxide on the surface of Co-38Mn-2La and Co-40Mn coatings, and (Co,Mn3O4 spinel continues to grow with extended oxidation time. The outmost scales of Co-33Mn-17Cu are mainly composed of cubic MnCo2O4 spinel with Mn2O3 after oxidation for 20 h and 100 h. The average thickness of oxide coatings is about 60–70 μm after oxidation for 100 h, except that Co-40Mn oxide coatings are a little thicker. Area-specific resistance of Cu/La doped Co-Mn coatings are lower than that of Co-40Mn coating. (Mn,Co3O4/MnCo2O4 spinel layer is efficient at blocking the outward diffusion of chromium and iron.

  15. Allergic reactions

    Science.gov (United States)

    ... that don't bother most people (such as venom from bee stings and certain foods, medicines, and pollens) can ... person. If the allergic reaction is from a bee sting, scrape the ... more venom. If the person has emergency allergy medicine on ...

  16. Therapeutic effects and adverse drug reactions are affected by icotinib exposure and CYP2C19 and EGFR genotypes in Chinese non-small cell lung cancer patients.

    Science.gov (United States)

    Chen, Jia; Zheng, Xin; Liu, Dong-Yang; Zhao, Qian; Wu, Yi-Wen; Tan, Fen-Lai; Wang, Yin-Xiang; Jiang, Ji; Hu, Pei

    2014-01-01

    The aim of this study was to evaluate how CYP2C19 affects icotinib and metabolite' exposure, and to determine whether the exposure and EGFR genotype influences survival time, tumor metastasis and adverse drug reactions. 274 NSCLC patients who accepted 125 mg icotinib/t.i.d. were chosen from a phase III study. Blood samples were obtained in 672 nd (4th week) and 1,680 th hours (10th week), and plasma was used to quantify the concentration of icotinib and blood cells were sampled to check the genotypes. Clinical data were also collected at the same time, including EGFR genotypes. Plasma concentrations were assessed by HPLC-MS/MS and genotype by sequencing. All data were analyzed through SPSS 17.0 and SAS 9.2. CYP 2C19 genotypes affected bio-transformation from icotinib to M24 and M26, especially in poor-metabolisers. Higher icotinib concentrations (>1000 ng/mL) not only increased patient PFS and OS but also reduced tumor metastasis. Patients with mutant EGFR experienced a higher median PFS and OS (234 and 627 days), especially those with the 19del genotype demonstrating higher PR ratio. Patients who suffered grade II skin toxicity had a higher icotinib exposure than those with grade I skin toxicity or no adverse effects. Liver toxic reactions might occur in patients with greater M20 and M23 plasma concentrations. CYP2C19 polymorphisms significantly affect icotinib, M24 and M26 exposure. Patients with mutant EGFR genotype and higher icotinib concentration might have increased PFS and OS and lower tumor metastasis. Liver ADR events and serious skin effects might be respectively induced by greater M20, M23 and icotinib concentrations.

  17. On the impedance of galvanic cells XXVII. The temperature-dependence of the kinetic parameters of the hydrogen electrode reaction on mercury in concentrated HI

    NARCIS (Netherlands)

    Dekker, B.G.; Sluyters-Rehbach, M.; Sluyters, J.H.

    1969-01-01

    The impedance of a dropping mercury electrode in 57% HI (7.6 M) was measured at temperatures between −35° and +25°C. In a certain potential and temperature region, two reactions were found to be proceeding simultaneously: the reversible Hg/HgI4−2 reaction and the irreversible H+/H2(Hg) reaction.

  18. Reduction reaction of chlorine gas in an Al-Cl2 chemical cell composed of molten chloride salts; Enkabutsu yoyuenkei Al-Cl2 kagaku denchi ni okeru enso gas no kangen hanno kyodo

    Energy Technology Data Exchange (ETDEWEB)

    Konda, S.; Sasaki, T.; Ishikawa, T. [Hokkaido University, Sapporo (Japan)

    1996-10-05

    The molten salt system electrochemical cycle was proposed to reproduce pure Al from scrap Al. The cycle is composed of production of rough AlCl3 by chlorination of scrap Al, refining of rough AlCl3 mainly by sublimation, and electrolytic reproduction of pure Al from refined AlCl3. In production of AlCl3, the Al-Cl2 molten salt system cell composed of anode dissolution reaction of Al and cathode reduction reaction of chlorine gas can generate electric power for the electrolytic reproduction. Chlorine gas can be recycled as anode product. Various experiments were carried out to improve molten salt system cells. In analysis of cell output, voltage drop from open circuit voltage was divided into that due to electrolytic bath resistance, and that due to reaction resistance. The electrolytic bath resistance could be determined from transient characteristics of voltage change just after cutoff of output current. The product of the obtained reaction resistance and a meniscus length was constant regardless of a meniscus length, and useful to predict scale-up cell performance. Output characteristics dependent on meniscus position were also obtained. 16 refs., 11 figs.

  19. Direct analysis of prostaglandin-E2 and -D2 produced in an inflammatory cell reaction and its application for activity screening and potency evaluation using turbulent flow chromatography liquid chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Shin, Jeong-Sook; Peng, Lei; Kang, Kyungsu; Choi, Yongsoo

    2016-09-09

    Direct analysis of prostaglandin-E2 (PGE2) and -D2 (PGD2) produced from a RAW264.7 cell-based reaction was performed by liquid chromatography high-resolution mass spectrometry (LC-HRMS), which was online coupled with turbulent flow chromatography (TFC). The capability of this method to accurately measure PG levels in cell reaction medium containing cytokines or proteins as a reaction byproduct was cross-validated by two conventional methods. Two methods, including an LC-HRMS method after liquid-liquid extraction (LLE) of the sample and a commercial PGE2 enzyme-linked immunosorbent assay (ELISA), showed PGE2 and/or PGD2 levels almost similar to those obtained by TFC LC-HRMS over the reaction time after LPS stimulation. After the cross-validation, significant analytical throughputs, allowing simultaneous screening and potency evaluation of 80 natural products including 60 phytochemicals and 20 natural product extracts for the inhibition of the PGD2 produced in the cell-based inflammatory reaction, were achieved using the TFC LC-HRMS method developed. Among the 60 phytochemicals screened, licochalcone A and formononetin inhibited PGD2 production the most with IC50 values of 126 and 151nM, respectively. For a reference activity, indomethacin and diclofenac were used, measuring IC50 values of 0.64 and 0.21nM, respectively. This method also found a butanol extract of Akebia quinata Decne (AQ) stem as a promising natural product for PGD2 inhibition. Direct and accurate analysis of PGs in the inflammatory cell reaction using the TFC LC-HRMS method developed enables the high-throughput screening and potency evaluation of as many as 320 samples in less than 48h without changing a TFC column. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Template-free synthesis of three-dimensional nanoporous N-doped graphene for high performance fuel cell oxygen reduction reaction in alkaline media

    International Nuclear Information System (INIS)

    Tang, Sheng; Zhou, Xuejun; Xu, Nengneng; Bai, Zhengyu; Qiao, Jinli; Zhang, Jiujun

    2016-01-01

    Highlights: • 3-D porous N-doped graphene was prepared using one-step silica template-free method. • High specific surface area of 920 m 2 g −1 was achieved for 3-D porous N-doped graphene. • Much higher ORR activity was observed for N-doped graphene than S-doped one in 0.1 M KOH. • The as-prepared catalyst gave a peak power density of 275 mW cm −2 as zinc–air battery cathode. - Abstract: Three-dimensional nanoporous nitrogen-doped graphene (3D-PNG) has been synthesized through a facial one-step synthesis method without additional silica template. The as-prepared 3D-PNGwas used as an electrocatalyst for the oxygen reduction reaction (ORR), which shows excellent electrochemistry performance, demonstrated by half-cell electrochemical evaluation in 0.1 M KOH including prominent ORR activity, four electron-selectivity and remarkable methanol poisoning stability compared to commercial 20%Pt/C catalyst. The physical and surface properties of 3D-PNG catalyst were characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and BET surface area analysis. The experiments show that 3D-PNG catalyst possesses super-large specific surface area reaching 920 m 2 g −1 , which is superior to our most recently reported 3D-PNG synthesized by silica template (670 m 2 g −1 ) and other doped graphene catalysts in literature. When used for constructing a zinc–air battery cathode, such an 3D-PNG catalyst can give a discharge peak power density of 275 mW cm −2 . All the results announce a unique procedure to product high-efficiency graphene-based non-noble metal catalyst materials for electrochemical energy devices including both fuel cells and metal–air batteries.

  1. Human parvovirus B19, varicella zoster virus, and human herpesvirus-6 in mesenchymal stem cells of patients with osteoarthritis: analysis with quantitative real-time polymerase chain reaction.

    Science.gov (United States)

    Rollín, R; Alvarez-Lafuente, R; Marco, F; Jover, J A; Hernández-García, C; Rodríguez-Navas, C; López-Durán, L; Fernández-Gutiérrez, B

    2007-04-01

    To investigate whether there is a possible viral transmission using mesenchymal stem cells (MSCs) in autologous or allogeneic transplantation in the context of osteoarthritis (OA) patients. The presence of parvovirus B19 (B19), varicella zoster virus (VZV), and human herpesvirus-6 (HHV-6) was studied in MSCs from bone marrow of patients with OA and healthy controls. MSCs were prepared from bone marrow aspirates obtained from 18 patients undergoing joint replacement as a result of OA and from 10 healthy controls. DNA was extracted from primary MSCs' culture established from these cells and quantitative real-time polymerase chain reaction was performed to analyse the prevalence and viral load of B19, VZV and HHV-6. The prevalence of total viral DNA among patients with OA was 16.7% (3/18), with a mean viral load of 29.7 copies/microg of DNA. One out of 18 was positive for B19 (viral load, 61.2 copies/microg of DNA), two for VZV (mean viral load, 14.4 copies/microg of DNA), and none for HHV-6. The prevalence of total viral DNA in the control group was 20% (2/10), with a mean viral load of 13.4 copies/microg of DNA. Both positive results were of B19 parvoviruses. There were no statistically significant differences among patients and controls. This first approach to the viral prevalence in MSCs of bone marrow in OA patients and healthy controls seems to show a very low risk of viral transmission or reactivation in a possible MSCs' transplantation.

  2. Analysis of twenty five impurities in uranium matrix by ICP-MS with iron measurement optimized by using reaction collision cell, cold plasma or medium resolution

    International Nuclear Information System (INIS)

    Quemet, Alexandre; Brennetot, Rene; Chevalier, Emilie; Prian, Edwina; Laridon, Anne-Laure; Fichet, Pascal; Goutelard, Florence; Mariet, Clarisse; Laszak, Ivan

    2012-01-01

    An analytical procedure was developed to determine the concentration of 25 impurities (Li, Be, Ti, V. Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ag, Cd, In, Sm, Eu, Gd, Dy, W, Pb, Bi and Th) in a uranium matrix using the quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS). The dissolution of U 3 O 8 powder was made with a mixture of hydrochloric acid and nitric acid. Then, a selective separation of uranium using the UTEVA column was used before measurement by Q-ICP-MS. The procedure developed was verified using the Certified Reference Material 'Morille'. The analytical results agree well except for 5 elements where values are underestimated (Li, Be, In, Pb and Bi). Among the list of impurities, iron was particularly investigated because it is well known that this element possesses a polyatomic interference that increases the detection limit. A comparison between iron detection limits obtained with different methods was performed. Iron polyatomic interference was at least reduced, or at best entirely resolved in some cases, by using the cold plasma or the collision/reaction cell with several gases (He, NH 3 and CH 4 ). High-resolution ICP-MS was used to compare the results obtained. A detection limit as low as 8 ng L -1 was achieved. (authors)

  3. Microwave-Assisted Synthesis of Reduced Graphene Oxide/SnO2 Nanocomposite for Oxygen Reduction Reaction in Microbial Fuel Cells.

    Science.gov (United States)

    Garino, Nadia; Sacco, Adriano; Castellino, Micaela; Muñoz-Tabares, José Alejandro; Chiodoni, Angelica; Agostino, Valeria; Margaria, Valentina; Gerosa, Matteo; Massaglia, Giulia; Quaglio, Marzia

    2016-02-01

    We report on an easy, fast, eco-friendly, and reliable method for the synthesis of reduced graphene oxide/SnO2 nanocomposite as cathode material for application in microbial fuel cells (MFCs). The material was prepared starting from graphene oxide that has been reduced to graphene during the hydrothermal synthesis of the nanocomposite, carried out in a microwave system. Structural and morphological characterizations evidenced the formation of nanocomposite sheets, with SnO2 crystals of few nanometers integrated in the graphene matrix. Physico-chemical analysis revealed the formation of SnO2 nanoparticles, as well as the functionalization of the graphene by the presence of nitrogen atoms. Electrochemical characterizations put in evidence the ability of such composite to exploit a cocatalysis mechanism for the oxygen reduction reaction, provided by the presence of both SnO2 and nitrogen. In addition, the novel composite catalyst was successfully employed as cathode in seawater-based MFCs, giving electrical performances comparable to those of reference devices employing Pt as catalyst.

  4. Analysis of twenty five impurities in uranium matrix by ICP-MS with iron measurement optimized by using reaction collision cell, cold plasma or medium resolution.

    Science.gov (United States)

    Quemet, Alexandre; Brennetot, Rene; Chevalier, Emilie; Prian, Edwina; Laridon, Anne-Laure; Mariet, Clarisse; Fichet, Pascal; Laszak, Ivan; Goutelard, Florence

    2012-09-15

    An analytical procedure was developed to determine the concentration of 25 impurities (Li, Be, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Ag, Cd, In, Sm, Eu, Gd, Dy, W, Pb, Bi and Th) in a uranium matrix using the quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS). The dissolution of U(3)O(8) powder was made with a mixture of hydrochloric acid and nitric acid. Then, a selective separation of uranium using the UTEVA column was used before measurement by Q-ICP-MS. The procedure developed was verified using the Certified Reference Material "Morille". The analytical results agree well except for 5 elements where values are underestimated (Li, Be, In, Pb and Bi). Among the list of impurities, iron was particularly investigated because it is well known that this element possesses a polyatomic interference that increases the detection limit. A comparison between iron detection limits obtained with different methods was performed. Iron polyatomic interference was at least reduced, or at best entirely resolved in some cases, by using the cold plasma or the collision/reaction cell with several gases (He, NH(3) and CH(4)). High-resolution ICP-MS was used to compare the results obtained. A detection limit as low as 8 ng L(-1) was achieved. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Analysis of phosphorus herbicides by ion-pairing reversed-phase liquid chromatography coupled to inductively coupled plasma mass spectrometry with octapole reaction cell.

    Science.gov (United States)

    Sadi, Baki B M; Vonderheide, Anne P; Caruso, Joseph A

    2004-09-24

    A reversed phase ion-pairing high performance liquid chromatographic (RPIP-HPLC) method is developed for the separation of two phosphorus herbicides, Glufosinate and Glyphosate as well as Aminomethylphosphonic acid (AMPA), the major metabolite of Glyphosate. Tetrabutylammonium hydroxide is used as the ion-pairing reagent in conjunction with an ammonium acetate/acetic acid buffering system at pH 4.7. An inductively coupled plasma mass spectrometer (ICP-MS) is coupled to the chromatographic system to detect the herbicides at m/z = 31P. Historically, phosphorus has been recognized as one of the elements difficult to analyze in argon plasma. This is due to its relatively high ionization potential (10.5 eV) as well as the inherent presence of the polyatomic interferences 14N16O1H+ and 15N16O+ overlapping its only isotope at m/z = 31. An octapole reaction cell is utilized to minimize the isobaric polyatomic interferences and to obtain the highest signal-to-background ratio. Detection limits were found to be in the low ppt range (25-32 ng/l). The developed method is successfully applied to the analysis of water samples collected from the Ohio River and spiked with a standard compounds at a level of 20 microg/l.

  6. Genetic Association of Curative and Adverse Reactions to Tyrosine Kinase Inhibitors in Chinese advanced Non-Small Cell Lung Cancer patients

    Science.gov (United States)

    Ruan, Yunfeng; Jiang, Jie; Guo, Liang; Li, Yan; Huang, Hailiang; Shen, Lu; Luan, Mengqi; Li, Mo; Du, Huihui; Ma, Cheng; He, Lin; Zhang, Xiaoqing; Qin, Shengying

    2016-01-01

    Epidermal growth factor receptor (EGFR) Tyrosine kinase inhibitor (TKI) is an effective targeted therapy for advanced non-small cell lung cancer (NSCLC) but also causes adverse drug reactions (ADRs) e.g., skin rash and diarrhea. SNPs in the EGFR signal pathway, drug metabolism/ transport pathways and miRNA might contribute to the interpersonal difference in ADRs but biomarkers for therapeutic responses and ADRs to TKIs in Chinese population are yet to be fully investigated. We recruited 226 Chinese advanced NSCLC patients who received TKIs erlotinib, gefitinib and icotinib hydrochloride and systematically studied the genetic factors associated with therapeutic responses and ADRs. Rs884225 (T > C) in EGFR 3′ UTR was significantly associated with lower risk of ADRs to erlotinib (p value = 0.0010, adjusted p value = 0.042). A multivariant interaction four-SNP model (rs884225 in EGFR 3′UTR, rs7787082 in ABCB1 intron, rs38845 in MET intron and rs3803300 in AKT1 5′UTR) was associated with ADRs in general and the more specific drug induced skin injury. The SNPs associated with both therapeutic responses and ADRs indicates they might share a common genetic basis. Our study provided potential biomarkers and clues for further research of biomarkers for therapeutic responses and ADRs in Chinese NSCLC patients. PMID:26988277

  7. Successive ionic layer adsorption and reaction deposited kesterite Cu{sub 2}ZnSnS{sub 4} nanoflakes counter electrodes for efficient dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mali, Sawanta S.; Shim, Chang Su; Hong, Chang Kook, E-mail: hongck@chonnam.ac.kr

    2014-11-15

    Highlights: • Cu{sub 2}ZnSnS{sub 4} nanoflakes by SILAR technique. • Hydrothermal synthesis of TiO{sub 2}. • Counter electrode for DSSC application. • 4.48% conversion efficiency. - Abstract: In this investigation, we have successfully synthesized Cu{sub 2}ZnSnS{sub 4} (CZTS) nanoflakes by successive ionic layer adsorption and reaction (SILAR) method and used as a counter electrode in the hydrothermally grown TiO{sub 2} based dye sensitized solar cells (DSSCs). The prepared CZTS nanoflakes were characterized using X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), micro Raman spectroscopy and energy dispersive analysis. Our DSSCs results revealed that, compared with conventional Pt/FTO counter electrode DSSCs, nanoflakes of p-type CZTS as the photocathode and n-type TiO{sub 2} thin films as the photoanode shows an increased short circuit current (13.35 mA/cm{sup 2}) with 4.84% power conversion efficiency. The detailed interface properties of were analyzed by electrochemical impedance spectroscopy (EIS) measurements.

  8. Successive ionic layer adsorption and reaction deposited kesterite Cu2ZnSnS4 nanoflakes counter electrodes for efficient dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Mali, Sawanta S.; Shim, Chang Su; Hong, Chang Kook

    2014-01-01

    Highlights: • Cu 2 ZnSnS 4 nanoflakes by SILAR technique. • Hydrothermal synthesis of TiO 2 . • Counter electrode for DSSC application. • 4.48% conversion efficiency. - Abstract: In this investigation, we have successfully synthesized Cu 2 ZnSnS 4 (CZTS) nanoflakes by successive ionic layer adsorption and reaction (SILAR) method and used as a counter electrode in the hydrothermally grown TiO 2 based dye sensitized solar cells (DSSCs). The prepared CZTS nanoflakes were characterized using X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), micro Raman spectroscopy and energy dispersive analysis. Our DSSCs results revealed that, compared with conventional Pt/FTO counter electrode DSSCs, nanoflakes of p-type CZTS as the photocathode and n-type TiO 2 thin films as the photoanode shows an increased short circuit current (13.35 mA/cm 2 ) with 4.84% power conversion efficiency. The detailed interface properties of were analyzed by electrochemical impedance spectroscopy (EIS) measurements

  9. Enhanced photovoltaic performance of CdS-sensitized inverted organic solar cells prepared via a successive ionic layer adsorption and reaction method

    Science.gov (United States)

    Oleiwi, Hind Fadhil; Zakaria, Azmi; Yap, Chi Chin; Abbas, Haidr Abdulzahra; Tan, Sin Tee; Lee, Hock Beng; Tan, Chun Hui; Ginting, Riski Titian; Alshanableh, Abdelelah; Talib, Zainal Abidin

    2017-05-01

    One-dimensional ZnO nanorods (ZNRs) synthesized on fluorine-doped tin oxide (FTO) glass by hydrothermal method were modified with cadmium sulfide quantum dots (CdS QDs) as an electron transport layer (ETL) in order to enhance the photovoltaic performance of inverted organic solar cell (IOSC). In present study, CdS QDs were deposited on ZNRs using a Successive Ionic Layer Adsorption and Reaction method (SILAR) method. In typical procedures, IOSCs were fabricated by spin-coating the P3HT:PC61BM photoactive layer onto the as-prepared ZNRs/CdS QDs. The results of current-voltage (I-V) measurement under illumination shows that the FTO/ZNRs/CdS QDs/ P3HT:PC61BM/ PEDOT: PSS/Ag IOSC achieved a higher power conversion efficiency (4.06 %) in comparison to FTO/ZNRs/P3HT:PC61BM/PEDOT: PSS/Ag (3.6 %). Our findings suggest that the improved open circuit voltage (Voc) and short circuit current density (Jsc) of ZNRs/CdS QDs devices could be attributed to enhanced electron selectivity and reduced interfacial charge carrier recombination between ZNRs and P3HT:PC61BM after the deposition of CdS QDs. The CdS QDs sensitized ZNRs reported herein exhibit great potential for advanced optoelectronic application.

  10. Rudimentary simple, single step fabrication of nano-flakes like AgCd alloy electro-catalyst for oxygen reduction reaction in alkaline fuel cell

    International Nuclear Information System (INIS)

    Bhandary, Nimai; Basu, Suddhasatwa; Ingole, Pravin P.

    2016-01-01

    In this work, for the first time, we report rudimentary simple, single step fabrication of an electro-catalyst based on AgCd alloy nanoparticles with flakes like geometry which shows highly efficient activity towards oxygen reduction reaction (ORR). A simple potentiostatic deposition method has been employed for co-depositing AgCd alloy nanostructures with flakes like shapes along with dendrites on the surface of carbon fibre paper. The chemico-physical properties of the catalyst are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDXS). Electro-catalytic activity of AgCd alloy based electro-catalyst towards ORR is studied in alkaline medium by cyclic voltammetry and rotating ring disk electrode (RRDE) technique. Electrochemical in-situ FTIR measurements are also performed to identify the species generated during ORR process. Based on the results from electro-catalysis experiment, it is concluded that nano-alloyed AgCd electrodeposited on carbon paper shows excellent activity for ORR, following four electron pathways with H_2O_2 yield less than 15%. The combination of low cost of Ag and Cd, fast and facile method of its fabrication and higher activity towards ORR makes the AgCd electro-catalyst an attractive catalyst of choice for alkaline fuel cell.

  11. Comparison of standard and reaction cell inductively coupled plasma mass spectrometry in the determination of chromium and selenium species by HPLC-ICP-MS

    International Nuclear Information System (INIS)

    Bednar, A.J.; Kirgan, R.A.; Jones, W.T.

    2009-01-01

    Elemental speciation is becoming a common analytical procedure for geochemical investigations. The various redox species of environmentally relevant metals can have vastly different biogeochemical properties, including sorption, solubility, bioavailability, and toxicity. The use of high performance liquid chromatography (HPLC) coupled to elemental specific detectors, such as inductively coupled plasma mass spectrometry (ICP-MS), has become one of the most important speciation methods employed. This is due to the separation versatility of HPLC and the sensitive and selective detection capabilities of ICP-MS. The current study compares standard mode ICP-MS to recently developed reaction cell (RC) ICP-MS, which has the ability to remove or reduce many common polyatomic interferences that can limit the ability of ICP-MS to quantitate certain analytes in complex matrices. Determination of chromium and selenium redox species is achieved using ion-exchange chromatography with elemental detection by standard and RC-ICP-MS, using various chromium and selenium isotopes. In this study, method performance and detection limits for the various permutations of the method (isotope monitored or ICP-MS detection mode) were found to be comparable and generally less than 1 μg L -1 . The method was tested on synthetic laboratory samples, surface water, groundwater, and municipal tap water matrices

  12. Activated carbon from orange peels as supercapacitor electrode and catalyst support for oxygen reduction reaction in proton exchange membrane fuel cell

    Directory of Open Access Journals (Sweden)

    M. Dhelipan

    2017-05-01

    Full Text Available Activated carbon is synthesized using orange peel as precursor through chemical activation using H3PO4 and its ability as electrocatalyst support for ORR reaction is examined. The prepared material was subjected to various structural, compositional, morphological and electrochemical studies. For ORR activity, the platinum loaded on activated carbon (Pt/OP-AC was investigated by cyclic voltammograms (CVs recorded in N2 and O2 saturated 0.1 M aqueous HClO4. For supercapacitor performance, three electrode systems was tested in aqueous H2SO4 for feasibility determination and showed electrochemical double layer capacitance (EDLC behaviour which is expected for activated carbon like materials. Electrochemical surface area (ECSA of the activated carbon from orange peel is measured using CV. The physical properties of the prepared carbon are studied using SEM (scanning electron microscope, XRD (X-ray diffraction, Fourier transform infrared (FT-IR spectroscopy and Raman spectroscopy. The AC derived from orange peels delivered a high specific capacitance of 275 F g−1 at 10 mV s-1 scan rate. Hence, this study suggested that orange peels may be considered not only as a potential alternative source for synthesizing carbon supported catalyst for fuel cell application but also highlight the production of low-cost carbon for further applications like supercapacitors.

  13. Visual detection of glial cell line-derived neurotrophic factor based on a molecular translator and isothermal strand-displacement polymerization reaction.

    Science.gov (United States)

    Zhang, Li-Yong; Xing, Tao; Du, Li-Xin; Li, Qing-Min; Liu, Wei-Dong; Wang, Ji-Yue; Cai, Jing

    2015-01-01

    Glial cell line-derived neurotrophic factor (GDNF) is a small protein that potently promotes the survival of many types of neurons. Detection of GDNF is vital to monitoring the survival of sympathetic and sensory neurons. However, the specific method for GDNF detection is also un-discovered. The purpose of this study is to explore the method for protein detection of GDNF. A novel visual detection method based on a molecular translator and isothermal strand-displacement polymerization reaction (ISDPR) has been proposed for the detection of GDNF. In this study, a molecular translator was employed to convert the input protein to output deoxyribonucleic acid signal, which was further amplified by ISDPR. The product of ISDPR was detected by a lateral flow biosensor within 30 minutes. This novel visual detection method based on a molecular translator and ISDPR has very high sensitivity and selectivity, with a dynamic response ranging from 1 pg/mL to 10 ng/mL, and the detection limit was 1 pg/mL of GDNF. This novel visual detection method exhibits high sensitivity and selectivity, which is very simple and universal for GDNF detection to help disease therapy in clinical practice.

  14. High Performance and Cost-Effective Direct Methanol Fuel Cells: Fe-N-C Methanol-Tolerant Oxygen Reduction Reaction Catalysts.

    Science.gov (United States)

    Sebastián, David; Serov, Alexey; Artyushkova, Kateryna; Gordon, Jonathan; Atanassov, Plamen; Aricò, Antonino S; Baglio, Vincenzo

    2016-08-09

    Direct methanol fuel cells (DMFCs) offer great advantages for the supply of power with high efficiency and large energy density. The search for a cost-effective, active, stable and methanol-tolerant catalyst for the oxygen reduction reaction (ORR) is still a great challenge. In this work, platinum group metal-free (PGM-free) catalysts based on Fe-N-C are investigated in acidic medium. Post-treatment of the catalyst improves the ORR activity compared with previously published PGM-free formulations and shows an excellent tolerance to the presence of methanol. The feasibility for application in DMFC under a wide range of operating conditions is demonstrated, with a maximum power density of approximately 50 mW cm(-2) and a negligible methanol crossover effect on the performance. A review of the most recent PGM-free cathode formulations for DMFC indicates that this formulation leads to the highest performance at a low membrane-electrode assembly (MEA) cost. Moreover, a 100 h durability test in DMFC shows suitable applicability, with a similar performance-time behavior compared to common MEAs based on Pt cathodes. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Multiplex polymerase chain reaction-based prognostic models in diffuse large B-cell lymphoma patients treated with R-CHOP

    DEFF Research Database (Denmark)

    Green, Tina M; Jensen, Andreas K; Holst, René

    2016-01-01

    We present a multiplex analysis for genes known to have prognostic value in an attempt to design a clinically useful classification model in patients with diffuse large B-cell lymphoma (DLBCL). Real-time polymerase chain reaction was used to measure transcript levels of 28 relevant genes in 194 de...... models. The best model was validated in data from an online available R-CHOP treated cohort. With progression-free survival (PFS) as primary endpoint, the best performing IPI independent model incorporated the LMO2 and HLADQA1 as well as gene interactions for GCSAMxMIB1, GCSAMxCTGF and FOXP1xPDE4B....... This model assigned 33% of patients (n = 60) to poor outcome with an estimated 3-year PFS of 40% vs. 87% for low risk (n = 61) and intermediate (n = 60) risk groups (P model incorporated LMO2 and BCL2 and assigned 33% of the patients with a 3-year PFS of 35% vs...

  16. Quasielastic reactions

    International Nuclear Information System (INIS)

    Hansen, O.

    1983-01-01

    A brief review is presented of the experimental and theoretical situation regarding transfer reactions and inelastic scattering. In the first category there is little (very little) precision data for heavy projectiles and consequently almost no experience with quantitative theoretical analysis. For the inelastic scattering the rather extensive data strongly supports the coupled channels models with collective formfactors. At the most back angles, at intensities about 10 -5 of Rutherford scattering, a second, compound-like mechanism becomes dominant. The description of the interplay of these two opposite mechanisms provides a new challenge for our understanding

  17. Evaluation of micronuclear frequencies in both circulating lymphocytes and buccal epithelial cells of patients with oral lichen planus and oral lichenoid contact reactions.

    Science.gov (United States)

    Saruhanoğlu, A; Ergun, S; Kaya, M; Warnakulasuriya, S; Erbağcı, M; Öztürk, Ş; Deniz, E; Özel, S; Çefle, K; Palanduz, Ş; Tanyeri, H

    2014-07-01

    The aim of this study was to evaluate the frequency of micronuclei (MNs) in both circulating lymphocytes and buccal epithelial cells of patients with oral lichenoid contact reactions (OLCRs) or with oral lichen planus (OLP) and compare their MN scores with those of healthy controls (HCs). The study group included 21 patients (mean age 51.3 ± 12.4; 6 males, 15 females) with OLCRs and 22 patients (mean age 47.6 ± 14.4; 4 males, 18 females) with OLP who were clinically diagnosed and histopathologically confirmed according to WHO diagnostic criteria (WHO Collaborating Centre for Oral Precancerous Lesions, 1978). All patients with OLCR demonstrated contact allergy to tested dental materials when evaluated by skin patch testing according to International Contact Dermatitis Research Group (ICDRG), while all OLP patients tested negative to patch testing. Seventeen individuals with no oral mucosal disorders (mean age 51.7 ± 11.3; 8 males, 9 females) were recruited to constitute the healthy control group. [Correction added on 30 May 2014, after first online publication: the term, 'mean age' has been added to the text in parenthesis throughout the Material and Methods section.] Clinical features including type of OLP, location, disease severity, presence of skin lesions, presence of systemic disease including any allergies and dental (periodontal) status were recorded. MN analyses were performed on peripheral blood lymphocytes and on smears of buccal epithelial cells of all three study groups. Most OLP and OLCR lesions were of reticular type (83%), and OLP lesions were distributed bilaterally on the buccal mucosa (90.5%). The medians of MN frequencies in buccal epithelial cells in OLP and OLCR groups were significantly higher when compared with HC group (P < 0.001). [Correction added on 30 May 2014, after first online publication: in the results, 2nd sentence, the word 'lymphocytes' has been removed.] There was no significant difference between OLP group (14

  18. Microbial activity in argillite waste storage cells for the deep geological disposal of French bituminous medium activity long lived nuclear waste: Impact on redox reaction kinetics and potential

    Science.gov (United States)

    Albrecht, A.; Leone, L.; Charlet, L.

    2009-04-01

    Micro-organisms are ubiquitous and display remarkable capabilities to adapt and survive in the most extreme environmental conditions. It has been recognized that microorganisms can survive in nuclear waste disposal facilities if the required major (P, N, K) and trace elements, a carbon and energy source as well as water are present. The space constraint is of particular interest as it has been shown that bacteria do not prosper in compacted clay. An evaluation of the different types of French medium and high level waste, in a clay-rich host rock storage environment at a depth between 500 and 600 m, has shown that the bituminous waste is the most likely candidate to accommodate significant microbial activity. The waste consists of a mixture of bitumen (source of bio-available organic matter and H2 as a consequence of its degradation and radiolysis) and nitrates and sulphates kept in a stainless steel container. The assumption, that microbes only have an impact on reaction kinetics needs to be reassessed in the case where nitrates and sulphates are present since both are known not to react at low temperatures without bacterial catalysis. The additional impact of both oxy-anions and their reduced species on redox conditions, radionuclide speciation and mobility gives this evaluation their particular relevance. Storage architecture proposes four primary waste containers positioned into armoured cement over packs and placed with others into the waste storage cell itself composed of a cement mantle enforcing the argillite host rock, the latter being characterized by an excavation damaged zone constricted both in space and in time and a pristine part of 60 m thickness. Bacterial activity within the waste and within the pristine argillite is disregarded because of the low water activity (biofilms are within the interface zones. A major restriction for the initial development of microbial colonies is the high pH controlled by the cement solution. Archea are able to survive

  19. Nuclear reactions

    International Nuclear Information System (INIS)

    Corner, J.; Richardson, K.; Fenton, N.

    1990-01-01

    Nuclear reactions' marks a new development in the study of television as an agency of public policy debate. During the Eighties, nuclear energy became a major international issue. The disasters at Three-mile Island and Chernobyl created a global anxiety about its risks and a new sensitivity to it among politicians and journalists. This book is a case-study into documentary depictions of nuclear energy in television and video programmes and into the interpretations and responses of viewers drawn from many different occupational groupings. How are the complex and specialist arguments about benefit, risk and proof conveyed through the different conventions of commentary, interview and film sequence? What symbolic associations does the visual language of television bring to portrayals of the issue? And how do viewers make sense of various and conflicting accounts, connecting what they see and hear on the screen with their pre-existing knowledge, experience and 'civic' expectations. The authors examine some of the contrasting forms and themes which have been used by programme makers to explain and persuade, and then give a sustained analysis of the nature and sources of viewers' own accounts. 'Nuclear Reactions' inquires into the public meanings surrounding energy and the environment, spelling out in its conclusion some of the implications for future media treatments of this issue. It is also a key contribution to the international literature on 'television knowledge' and the processes of active viewing. (author)

  20. Comparison of real-time reverse transcriptase polymerase chain reaction of peripheral blood mononuclear cells, serum and cell-free body cavity effusion for the diagnosis of feline infectious peritonitis.

    Science.gov (United States)

    Doenges, Stephanie J; Weber, Karin; Dorsch, Roswitha; Fux, Robert; Hartmann, Katrin

    2017-04-01

    Objectives Diagnosis of feline infectious peritonitis (FIP) remains challenging, especially in cats without effusions. The objective of this study was to evaluate the sensitivity and specificity of a real-time reverse transcriptase polymerase chain reaction (RT-PCR) detecting feline coronavirus (FCoV) RNA in peripheral blood mononuclear cells (PBMCs) and serum in comparison with the same real-time RT-PCR in cell-free body cavity effusion. Methods This prospective case-control study included 92 cats. Forty-three cats had a definitive diagnosis of FIP, established either by histopathological examination (n = 28) or by positive immunofluorescence staining of FCoV antigen in macrophages of effusions (n = 11), or by both methods (n = 4). Forty-nine control cats had other diseases but similar clinical signs. Real-time RT-PCR was performed on PBMCs of 37 cats (21 cats with FIP, 16 controls), on serum of 51 cats (26 cats with FIP, 25 controls) and on cell-free body cavity effusion of 69 cats (36 cats with FIP, 33 controls). Sensitivity, specificity, positive and negative predictive value, including 95% confidence intervals (CI), were calculated. Results Real-time RT-PCR of PBMCs, serum and cell-free body cavity effusion showed a specificity of 100% (95% CI 79.4-100% in PBMCs, 86.3-100% in serum, 89.4-100% in cell-free body cavity effusion) and a sensitivity of 28.6% (95% CI 11.3-52.2%) in PBMCs, 15.4% (95% CI 4.4-34.9%) in serum and 88.9% (95% CI 73.9-96.9%) in cell-free body cavity effusion to diagnose FIP. Conclusions and relevance Although it is known that RT-PCR can often provide false-positive results in healthy cats, this real-time RT-PCR was shown to be a specific tool for the diagnosis of FIP when applied in a clinical setting. Sensitivity in cell-free body cavity effusion was high but low in PBMCs and serum. PBMC samples showed a higher sensitivity than serum samples, and are therefore a better choice if no effusion is present.

  1. Laser ablation-inductively coupled plasma-dynamic reaction cell-mass spectrometry for the multi-element analysis of polymers

    International Nuclear Information System (INIS)

    Resano, M.; Garcia-Ruiz, E.; Vanhaecke, F.

    2005-01-01

    In this work, the potential of laser ablation-inductively coupled plasma-mass spectrometry for the fast analysis of polymers has been explored. Different real-life samples (polyethylene shopping bags, an acrylonitrile butadiene styrene material and various plastic bricks) as well as several reference materials (VDA 001 to 004, Cd in polyethylene) have been selected for the study. Two polyethylene reference materials (ERM-EC 680 and 681), for which a reference or indicative value for the most relevant metals is available, have proved their suitability as standards for calibration. Special attention has been paid to the difficulties expected for the determination of Cr at the μg g -1 level in this kind of materials, due to the interference of ArC + ions on the most abundant isotopes of Cr. The use of ammonia as a reaction gas in a dynamic reaction cell is shown to alleviate this problem, resulting in a limit of detection of 0.15 μg g -1 for this element, while limiting only modestly the possibilities of the technique for simultaneous multi-element analysis. In this regard, As is the analyte most seriously affected by the use of ammonia, and its determination has to be carried out in vented mode, at the expense of measuring time. In all cases studied, accurate results could be obtained for elements ranging in content from the sub-μg g -1 level to tens of thousands of μg g -1 . However, the use of an element of known concentration as internal standard may be needed for materials with a matrix significantly different from that of the standard (polyethylene in this work). Precision ranged between 5% and 10% RSD for elements found at the 10 μg g -1 level or higher, while this value could deteriorate to 20% for analytes found at the sub-μg g -1 level. Overall, the technique evaluated presents many advantages for the fast and accurate multi-element analysis of these materials, avoiding laborious digestion procedures and minimizing the risk of analyte losses due to the

  2. Spallation reactions; Reactions de spallation

    Energy Technology Data Exchange (ETDEWEB)

    Cugon, J.

    1996-12-31

    Spallation reactions dominate the interactions of hadrons with nuclei in the GeV range (from {approx} 0.1 to {approx} 10 GeV). They correspond to a sometimes important ejection of light particles leaving most of the time a residue of mass commensurate with the target mass. The main features of the experimental data are briefly reviewed. The most successful theoretical model, namely the intranuclear cascade + evaporation model, is presented. Its physical content, results and possible improvements are critically discussed. Alternative approaches are shortly reviewed. (author). 84 refs.

  3. Compensatory Cellular Reactions to Nonsteroidal Anti-Inflammatory Drugs on Osteogenic Differentiation in Canine Bone Marrow-Derived Mesenchymal Stem Cells

    Science.gov (United States)

    OH, Namgil; KIM, Sangho; HOSOYA, Kenji; OKUMURA, Masahiro

    2014-01-01

    ABSTRACT The suppressive effects of nonsteroidal anti-inflammatory drugs (NSAIDs) on the bone healing process have remained controversial, since no clinical data have clearly shown the relationship between NSAIDs and bone healing. The aim of this study was to assess the compensatory response of canine bone marrow-derived mesenchymal stem cells (BMSCs) to several classes of NSAIDs, including carprofen, meloxicam, indomethacin and robenacoxib, on osteogenic differentiation. Each of the NSAIDs (10 µM) was administered during 20 days of the osteogenic process with human recombinant IL-1β (1 ng/ml) as an inflammatory stimulator. Gene expression of osteoblast differentiation markers (alkaline phosphatase and osteocalcin), receptors of PGE2 (EP2 and EP4) and enzymes for prostaglandin (PG) E2 synthesis (COX-1, COX-2, cPGES and mPGES-1) was measured by using quantitative reverse transcription-polymerase chain reaction. Protein production levels of alkaline phosphatase, osteocalcin and PGE2 were quantified using an alkaline phosphatase activity assay, osteocalcin immunoassay and PGE2 immunoassay, respectively. Histologic analysis was performed using alkaline phosphatase staining, von Kossa staining and alizarin red staining. Alkaline phosphatase and calcium deposition were suppressed by all NSAIDs. However, osteocalcin production showed no significant suppression by NSAIDs. Gene expression levels of PGE2-related receptors and enzymes were upregulated during continuous treatment with NSAIDs, while certain channels for PGE2 synthesis were utilized differently depending on the kind of NSAIDs. These data suggest that canine BMSCs have a compensatory mechanism to restore PGE2 synthesis, which would be an intrinsic regulator to maintain differentiation of osteoblasts under NSAID treatment. PMID:24419976

  4. Novel thin/tunable gas diffusion electrodes with ultra-low catalyst loading for hydrogen evolution reactions in proton exchange membrane electrolyzer cells

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Zhenye; Yang, Gaoqiang; Mo, Jingke; Li, Yifan; Yu, Shule; Cullen, David A.; Retterer, Scott T.; Toops, Todd J.; Bender, Guido; Pivovar, Bryan S.; Green, Johney B.; Zhang, Feng-Yuan

    2018-05-01

    Proton exchange membrane electrolyzer cells (PEMECs) have received great attention for hydrogen/oxygen production due to their high efficiencies even at low-temperature operation. Because of the high cost of noble platinum-group metal (PGM) catalysts (Ir, Ru, Pt, etc.) that are widely used in water splitting, a PEMEC with low catalyst loadings and high catalyst utilizations is strongly desired for its wide commercialization. In this study, the ultrafast and multiscale hydrogen evolution reaction (HER) phenomena in an operating PEMEC is in-situ observed for the first time. The visualization results reveal that the HER and hydrogen bubble nucleation mainly occur on catalyst layers at the rim of the pores of the thin/tunable liquid/gas diffusion layers (TT-LGDLs). This indicates that the catalyst material of the conventional catalyst-coated membrane (CCM) that is located in the middle area of the LGDL pore is underutilized/inactive. Based on this discovery, a novel thin and tunable gas diffusion electrode (GDE) with a Pt catalyst thickness of 15 nm and a total thickness of about 25 um has been proposed and developed by taking advantage of advanced micro/nano manufacturing. The novel thin GDEs are comprehensively characterized both ex-situ and in-situ, and exhibit excellent PEMEC performance. More importantly, they achieve catalyst mass activity of up to 58 times higher than conventional CCM at 1.6 V under the operating conditions of 80 degrees C and 1 atm. This study demonstrates a promising concept for PEMEC electrode development, and provides a direction of future catalyst designs and fabrications for electrochemical devices.

  5. X-ray absorption spectroscopy study of the LixFePO4 cathode during cycling using a novel electrochemical in situ reaction cell

    International Nuclear Information System (INIS)

    Deb, A.; Bergmann, U.; Cairns, E.L.; California Univ., Berkeley, CA; Cramer, S.P.; California Univ., Davis, CA

    2004-01-01

    The extraction and insertion of lithium in LiFePO 4 has been investigated in practical Li-ion intercalation electrodes for Li-ion batteries using Fe K-edge X-ray absorption spectroscopy (XAS). A versatile electrochemical in situ reaction cell was utilized, specifically designed for long-term X-ray experiments on battery electrodes during the lithium-extraction/insertion process in electrode materials for Li-ion batteries. The electrode contained about 7.7 mg of LiFePO 4 on a 20 μm-thick Al foil. In order to determine the charge compensation mechanism and structural perturbations occurring in the system during cycling, in situ X-ray absorption fine-structure spectroscopy (XAFS) measurements were conducted on the cell at a moderate rate using typical Li-ion battery operating voltages (3.0-4.1 V versus Li/Li + ).XAS studies of the LiFePO 4 electrode measured at the initial state (LiFePO 4 ) showed iron to be in the Fe(II) state corresponding to the initial state (0.0 mAh) of the battery, whereas in the delithiated state (FePO 4 ) iron was found to be in the FE(III) state corresponding to the final charged state (3 m Ah) of the battery. The X-ray absorption near-edge structure (XANES) region of the XAS spectra revealed a high-spin configuration for the two states [Fe(II), d 6 and Fe(III), d 5 ]. The XAFS data analysis confirmed that the olivine structure of the LeFePO 4 and FePO 4 is retained by the electrodes, which is in agreement with the X-ray diffraction observations on these compounds. The XAFS data that were collected continuously during cycling revealed details about the response of the cathode to Li insertion and extraction. These measurements on the LiFePO 4 cathode show that the material retains good structural short-range order leading to superior cycling

  6. Histopathology and immune histochemistry of red tattoo reactions. Interface dermatitis is the lead pathology, with increase in T-lymphocytes and Langerhans cells suggesting an allergic pathomechanism

    DEFF Research Database (Denmark)

    Høgsberg, T; Thomsen, B M; Serup, J

    2015-01-01

    BACKGROUND: The majority of tattoo reactions are affiliated to red pigmented areas and often suspected to be allergic in nature. A sizeable series of biopsies of such reactions has not previously been performed. The aim of this study was to type and grade epidermal and dermal changes in tattoo re...

  7. Development and Application of ANN Model for Worker Assignment into Virtual Cells of Large Sized Configurations

    International Nuclear Information System (INIS)

    Murali, R. V.; Fathi, Khalid; Puri, A. B.

    2010-01-01

    This paper presents an extended version of study already undertaken on development of an artificial neural networks (ANNs) model for assigning workforce into virtual cells under virtual cellular manufacturing systems (VCMS) environments. Previously, the same authors have introduced this concept and applied it to virtual cells of two-cell configuration and the results demonstrated that ANNs could be a worth applying tool for carrying out workforce assignments. In this attempt, three-cell configurations problems are considered for worker assignment task. Virtual cells are formed under dual resource constraint (DRC) context in which the number of available workers is less than the total number of machines available. Since worker assignment tasks are quite non-linear and highly dynamic in nature under varying inputs and conditions and, in parallel, ANNs have the ability to model complex relationships between inputs and outputs and find similar patterns effectively, an attempt was earlier made to employ ANNs into the above task. In this paper, the multilayered perceptron with feed forward (MLP-FF) neural network model has been reused for worker assignment tasks of three-cell configurations under DRC context and its performance at different time periods has been analyzed. The previously proposed worker assignment model has been reconfigured and cell formation solutions available for three-cell configuration in the literature are used in combination to generate datasets for training ANNs framework. Finally, results of the study have been presented and discussed.

  8. RxnFinder: biochemical reaction search engines using molecular structures, molecular fragments and reaction similarity.

    Science.gov (United States)

    Hu, Qian-Nan; Deng, Zhe; Hu, Huanan; Cao, Dong-Sheng; Liang, Yi-Zeng

    2011-09-01

    Biochemical reactions play a key role to help sustain life and allow cells to grow. RxnFinder was developed to search biochemical reactions from KEGG reaction database using three search criteria: molecular structures, molecular fragments and reaction similarity. RxnFinder is helpful to get reference reactions for biosynthesis and xenobiotics metabolism. RxnFinder is freely available via: http://sdd.whu.edu.cn/rxnfinder. qnhu@whu.edu.cn.

  9. Chain reaction

    International Nuclear Information System (INIS)

    Balogh, Brian.

    1991-01-01

    Chain Reaction is a work of recent American political history. It seeks to explain how and why America came to depend so heavily on its experts after World War II, how those experts translated that authority into political clout, and why that authority and political discretion declined in the 1970s. The author's research into the internal memoranda of the Atomic Energy Commission substantiates his argument in historical detail. It was not the ravages of American anti-intellectualism, as so many scholars have argued, that brought the experts back down to earth. Rather, their decline can be traced to the very roots of their success after World War II. The need to over-state anticipated results in order to garner public support, incessant professional and bureaucratic specialization, and the sheer proliferation of expertise pushed arcane and insulated debates between experts into public forums at the same time that a broad cross section of political participants found it easier to gain access to their own expertise. These tendencies ultimately undermined the political influence of all experts. (author)

  10. The development of a state-of-the-art experimental setup demonstrated by the investigation of fuel cell reactions in alkaline electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Wiberg, Gustav Karl Henrik

    2010-10-04

    The objectives of this work can be separated into three different topics: the design and development of a state-of-the art electrochemical experiment setup, which is then followed by two separate experimental studies in alkaline electrolyte. These studies demonstrate the capabilities of the experimental setup, and each focus on separate model catalysts. The first study investigated the influence of Pt oxide formation on the measured catalytic activity of FC relevant reactions on polycrystalline Pt in alkaline electrolyte. The second study focused on the characterisation of the ORR for a non-platinum catalyst, in this case Ag, by adapting the established thin-film RDE methodology employed for characterising Pt based electrocatalysts. A state-of-the-art electrochemical experimental setup comprises of a largely automated setup that allows meticulous control over experimental parameters such as potential, temperature, purging gas and solution convection. In order to realise such a setup, both experimental hardware and software were developed. In particular, a custom built analogue potentiostat optimised for single working electrode measurements was constructed. The potentiostat features R{sub sol}-compensation which can be monitored online due to its fully analogue design, allowing the precise current and potential relationship to be measured. In addition, the experimental throughput was enhanced by fabricating a modular add-on device, the MWE, which allows simultaneous electrochemical measurement on up to 8 parallel working electrodes. The MWE device is compatible with any single channel potentiostat, enhancing existing instrumentation. Several Teflon cells were designed for electrochemical investigations in acid and alkaline electrolytes, and were adapted to work using either the RDE or MWE. A gas changer was also assembled, which enabled computer controlled switching of electrolyte purge gas. Furthermore, in order to control the potentiostat and the accessory

  11. Lack of autologous mixed lymphocyte reaction in patients with chronic lymphocytic leukemia: evidence for autoreactive T-cell dysfunction not correlated with phenotype, karyotype, or clinical status

    International Nuclear Information System (INIS)

    Han, T.; Bloom, M.L.; Dadey, B.; Bennett, G.; Minowada, J.; Sandberg, A.A.; Ozer, H.

    1982-01-01

    In the present study, there was a complete lack of autologous MLR between responding T cells or T subsets and unirradiated or irradiated leukemic B cells or monocytes in all 20 patients with CLL, regardless of disease status, stage, phenotype, or karyotype of the disease. The stimulating capacity of unirradiated CLL B cells and CLL monocytes or irradiated CLL B cells was significantly depressed as compared to that of respective normal B cells and monocytes in allogeneic MLR. The responding capacity of CLL T cells was also variably lower than that of normal T cells against unirradiated or irradiated normal allogeneic B cells and monocytes. The depressed allogeneic MLR between CLL B cells or CLL monocytes and normal T cells described in the present study could be explained on the basis of a defect in the stimulating antigens of leukemic B cells or monocytes. The decreased allogeneic MLR of CLL T cells might simply be explained by a defect in the responsiveness of T lymphocytes from patients with CLL. However, these speculations do not adequately explain the complete lack of autologous MLR in these patients. When irradiated CLL B cells or irradiated CLL T cells were cocultured with normal T cells and irradiated normal B cells, it was found that there was no suppressor cell activity of CLL B cells or CLL T cells on normal autologous MLR. Our data suggest that the absence or dysfunction of autoreactive T cells within the Tnon-gamma subset account for the lack of autologous MLR in patients with CLL. The possible significance of the autologous MLR, its relationship to in vivo immunoregulatory mechanisms, and the possible role of breakdown of autoimmunoregulation in the oncogenic process of certain lymphoproliferative and autoimmune diseases in man are discussed

  12. Electrochemically assisted organosol method for Pt-Sn nanoparticle synthesis and in situ deposition on graphite felt support: Extended reaction zone anodes for direct ethanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Lycke, Derek R.; Gyenge, Elod L. [Department of Chemical and Biological Engineering, The University of British Columbia, 2360 East Mall, Vancouver, BC (Canada)

    2007-03-20

    Two electrochemically assisted variants of the Boenneman organosol method were developed for Pt-Sn nanoparticle synthesis and in situ deposition on graphite felt electrodes (e.g. thickness up to 2 mm). Tetraoctylammonium triethylhydroborate N(C{sub 8}H{sub 17}){sub 4}BH(C{sub 2}H{sub 5}){sub 3} was employed as colloid stabilizer and reductant dissolved in tetrahydrofuran (THF). The role of the electric field at a low deposition current density of 1.25 mA cm{sup -2} was mainly electrophoretic causing the migration and adsorption of N(C{sub 8}H{sub 17}){sub 4}BH(C{sub 2}H{sub 5}){sub 3} on the graphite felt surface where it reduced the PtCl{sub 2}-SnCl{sub 2} mixture. Faradaic electrodeposition was detected mostly for Sn. Typical Pt-Sn loadings were between 0.4 and 0.9 mg cm{sup -2} depending on the type of pre-deposition exposure of the graphite felt: surfactant-adsorption and metal-adsorption variant, respectively. The catalyst surface area and Pt:Sn surface area ratio was determined by anodic striping of an underpotential deposited Cu monolayer. The two deposition variants gave different catalyst surfaces: total area 233 and 76 cm{sup 2} mg{sup -1}, with Pt:Sn surface area ratio of 3.5:1 and 7.7:1 for surfactant and metal adsorption, respectively. Regarding electrocatalysis of ethanol oxidation, voltammetry and chronopotentiometry studies corroborated by direct ethanol fuel cell experiments using 0.5 M H{sub 2}SO{sub 4} as electrolyte, showed that due to a combination of higher catalyst load and Pt:Sn surface ratio, the graphite felt anodes prepared by the metal-adsorption variant gave better performance. The catalyzed graphite felt provided an extended reaction zone for ethanol electrooxidation and it gave higher catalyst mass specific peak power outputs compared to literature data obtained using gas diffusion anodes with carbon black supported Pt-Sn nanoparticles. (author)

  13. Low Energy Nuclear Reactions?

    CERN Multimedia

    CERN. Geneva; Faccini, R.

    2014-01-01

    After an introduction to the controversial problem of Low Energy Nuclear Reactions (LENR) catalyzed by neutrons on metallic hydride surfaces we present the results of an experiment, made in collaboration with ENEA Labs in Frascati, to search neutrons from plasma discharges in electrolytic cells. The negative outcome of our experiment goes in the direction of ruling out those theoretical models expecting LENR to occur in condensed matter systems under specific conditions. Our criticism on the theoretical foundations of such models will also be presented.

  14. Enhancing governance for sanitation marketing in DRC

    NARCIS (Netherlands)

    Klaver, D.C.

    2015-01-01

    This report is one of the results of the ‘Sanitation Marketing in Equateur Province’ project in RDC, in which Wageningen UR and Oxfam Great Britain (Oxfam GB) work together.

    • It Describes the characteristics of different governance arrangements that address sanitation problems in Gemena

  15. Urban violence and exclusion in the DRC

    International Development Research Centre (IDRC) Digital Library (Canada)

    support, children from impoverished households, many of whom are uneducated, are adding to the ... The goal of this study was to identify the dynamic interplay among poverty/exclusion ... The lack of public lighting and access points to water exposes girls to .... work together to develop more inclusive economic and social.

  16. Low-temperature (75 °C) solid-state reaction enhanced by less-crystallized nanoporous PbI2 films for efficient CH3NH3PbI3 perovskite solar cells

    International Nuclear Information System (INIS)

    Zheng, Huifeng; Liu, Yangqiao; Sun, Jing

    2017-01-01

    Highlights: • Efficient perovskite solar cells were prepared with solid-state reaction at 75 °C. • Ln-PbI 2 is superior to c-PbI 2 when applied in low-temperature solid-state reaction. • A higher champion PCE was obtained at 75 °C (13.8%) than that of 140 °C (11.8%). • Non-radiative defects increase significantly when annealed at high temperature. - Abstract: Organohalide perovskite films are usually prepared with the solid-state reaction at a high temperature ≥100 °C, which causes the increase of non-radiative defects and decomposition of perovskite films. Here, we demonstrate it’s feasible to prepare high-quality perovskite films with the solid-state reaction method even at a temperature of 75 °C, when enhanced by less-crystallized nanoporous PbI 2 (ln-PbI 2 ) films. The replacement of compact PbI 2 (c-PbI 2 ) by ln-PbI 2 , results in a significant improvement of crystallinity of perovskite films, besides the elimination of remnant PbI 2 . As a result, ln-PbI 2 based perovskite solar cells display much higher power conversion efficiency (PCE) and better stability. Moreover, annealing duration was found to be critical for high PCE and was optimized as 60 min. Finally, with the optimal process, the champion device displayed a PCE of 13.8% and the average PCE reached 10.1% with a satisfactory deviation. Furthermore, we found annealing at high temperature (140 °C) led to a lower PCE compared with that annealed at 75 °C, because non-radiative defects increased significantly during high-temperature annealing. This work may open up a promising avenue for preparing high-quality perovskite films with the low-temperature solid-state reaction method, which is desirable for real application.

  17. Chemical kinetics and reaction mechanism

    International Nuclear Information System (INIS)

    Jung, Ou Sik; Park, Youn Yeol

    1996-12-01

    This book is about chemical kinetics and reaction mechanism. It consists of eleven chapters, which deal with reaction and reaction speed on reaction mechanism, simple reaction by rate expression, reversible reaction and simultaneous reaction, successive reaction, complicated reaction mechanism, assumption for reaction mechanism, transition state theory, successive reaction and oscillating reaction, reaction by solution, research method high except kinetics on reaction mechanism, high reaction of kinetics like pulsed radiolysis.

  18. Effect of carbons (G and CFs), TM (Ni, Fe and Al) and oxides (Nb_2O_5 and V_2O_5) on hydrogen generation from ball milled Mg-based hydrolysis reaction for fuel cell

    International Nuclear Information System (INIS)

    Awad, A.S.; El-Asmar, E.; Tayeh, T.; Mauvy, F.; Nakhl, M.; Zakhour, M.; Bobet, J.-L.

    2016-01-01

    This paper dedicated to investigation the effect of carbons (graphite and carbon fibers), transition metals (TM = Ni, Fe and Al) and oxides (Nb_2O_5 and V_2O_5) on Mg–H hydrolysis reaction in aqueous media (3.5 wt% NaCl). Mg – 10 wt% X (X = C, TM and oxides) mixtures were prepared by mechanical milling (1, 3 and 5 h). Mg – 10 wt% G mixtures show the best hydrolysis performance (95% of theoretical hydrogen generation yield in almost 3 min) in comparison to Mg – oxide and Mg – TM mixtures. In addition to the presence of micro-galvanic cells, particle size, MgH_2 content, density defects, fractures and cracking have an important influence on the hydrolysis reaction. Synergetic effect of carbons and transition metals has been studied for Mg – 5 wt% G – 5 wt% Ni mixture. Activation energies were calculated using Avrami–Erofeev model. An activation energy of 14.34 kJ/mol was found for Mg/G/Ni mixture which demonstrates the best hydrolysis behavior (95% of theoretical hydrogen generation yield within 2 min). Hydrogen generated from Mg–H hydrolysis reaction was fed directly to a single Proton Exchange Membrane Fuel Cell (PEMFC). At 0.15 A, the cell voltage exhibited a stable value of approximately 0.52 V for roughly 35 min. - Highlights: • The presence of carbon and transition metals enhance the hydrolysis reaction of magnesium. • The synergetic effect of graphite and Ni leads to the best hydrolysis kinetics. • Cl"− ions replace OH"− ions to destabilize the Mg(OH)_2 passivation layer. • Production of electricity is feasible from hydrogen generated from Mg.

  19. An attempt to induce transient immunosuppression pre-erythrocytapheresis in a girl with sickle cell disease, a history of severe delayed hemolytic transfusion reactions and need for hip prosthesis

    Directory of Open Access Journals (Sweden)

    Alessandro Cattoni

    2013-06-01

    Full Text Available We report on a case of delayed hemolytic transfusion reaction (DHTR occurred 7 days after an erythrocytapheresis or eritroexchange procedure (EEX treated with rituximab and glucocorticoids in a 15-years old patient with sickle cell disease. EEX was performed despite a previous diagnosis of alloimmunization, in order to reduce hemoglobin S rate before a major surgery for avascular necrosis of the femoral head. A first dose of rituximab was administered before EEX. However, rituximab couldn’t prevent DHTR that occurred with acute hemolysis, hemoglobinuria and hyper-bilirubinemia. A further dose of rituximab and three boli of methylprednisolone were given after the onset of the reaction. It is likely that the combined use of rituximab and steroids managed to gradually improve both patient’s general conditions and hemoglobin levels. Nor early or late side effects were registered in a 33-months follow-up period. This report suggests the potential effectiveness and safety of rituximab in combination with steroids in managing and mitigating the symptoms of delayed post-transfusional hemolytic reactions in alloimmunized patients affected by sickle cell disease with absolute need for erythrocytapheresis.

  20. Reversal reaction in borderline leprosy is associated with a polarized shift to type 1-like Mycobacterium leprae T cell reactivity in lesional skin: a follow-up study

    NARCIS (Netherlands)

    Verhagen, C. E.; Wierenga, E. A.; Buffing, A. A.; Chand, M. A.; Faber, W. R.; Das, P. K.

    1997-01-01

    Borderline leprosy patients often undergo acute changes in immune reactivity that manifest as reversal reaction (RR) in the course of the disease. RR is associated with an exacerbated local delayed-type cellular immune response to Mycobacterium leprae and is responsible for severe tissue damage. We

  1. CD4(+)and CD8(+)T-cell reactions against leukemia-associated- or minor-histocompatibility-antigens in AML-patients after allogeneic SCT.

    Science.gov (United States)

    Steger, Brigitte; Milosevic, Slavoljub; Doessinger, Georg; Reuther, Susanne; Liepert, Anja; Braeu, Marion; Schick, Julia; Vogt, Valentin; Schuster, Friedhelm; Kroell, Tanja; Busch, Dirk H; Borkhardt, Arndt; Kolb, Hans-Jochem; Tischer, Johanna; Buhmann, Raymund; Schmetzer, Helga

    2014-04-01

    T-cells play an important role in the remission-maintenance in AML-patients (pts) after SCT, however the role of LAA- (WT1, PR1, PRAME) or minor-histocompatibility (mHag, HA1) antigen-specific CD4(+) and CD8(+)T-cells is not defined. A LAA/HA1-peptide/protein stimulation, cloning and monitoring strategy for specific CD8(+)/CD4(+)T-cells in AML-pts after SCT is given. Our results show that (1) LAA-peptide-specific CD8+T-cells are detectable in every AML-pt after SCT. CD8(+)T-cells, recognizing two different antigens detectable in 5 of 7 cases correlate with long-lasting remissions. Clonal TCR-Vβ-restriction exemplarily proven by spectratyping in PRAME-specific CD8(+)T-cells; high PRAME-peptide-reactivity was CD4(+)-associated, as shown by IFN-γ-release. (2) Two types of antigen-presenting cells (APCs) were tested for presentation of LAA/HA1-proteins to CD4(+)T-cells: miniEBV-transduced lymphoblastoid cells (B-cell-source) and CD4-depleted MNC (source for B-cell/monocyte/DC). We provide a refined cloning-system for proliferating, CD40L(+)CD4(+)T-cells after LAA/HA1-stimulation. CD4(+)T-cells produced cytokines (GM-CSF, IFN-γ) upon exposure to LAA/HA1-stimulation until after at least 7 restimulations and demonstrated cytotoxic activity against naive blasts, but not fibroblasts. Antileukemic activity of unstimulated, stimulated or cloned CD4(+)T-cells correlated with defined T-cell-subtypes and the clinical course of the disease. In conclusion we provide immunological tools to enrich and monitor LAA/HA1-CD4(+)- and CD8(+)T-cells in AML-pts after SCT and generate data with relevant prognostic value. We were able to demonstrate the presence of LAA-peptide-specific CD8(+)T-cell clones in AML-pts after SCT. In addition, we were also able to enrich specific antileukemic reactive CD4(+)T-cells without GvH-reactivity upon repeated LAA/HA1-protein stimulation and limiting dilution cloning. Copyright © 2013 Elsevier GmbH. All rights reserved.

  2. Cellular basis of the immunohematologic defects observed in short-term semiallogeneic B6C3F1→C3H chimeras: evidence for host-versus-graft reaction initiated by radioresistant T cells

    International Nuclear Information System (INIS)

    Aizawa, S.; Sado, T.; Kamisaku, H.; Kubo, E.

    1980-01-01

    Lethally irradiated C3Hf mice reconstituted with a relatively low dose (2 x 10 6 ) of B6C3F 1 bone marrow cells (B6C3F 1 →C3Hf chimeras) frequently manifest immunohematologic deficiencies during the first month following injection of bone marrow cells. They show slow recovery of antibody-forming potential to sheep red blood cells (SRBC) as compared to that observed in syngeneic (C3Hf→C3Hf or B6C3F 1 →B6C3F 1 ) chimeras. They also show a deficiency of B-cell activity as assessed by antibody response to SRBC following further reconstitution with B6C3F 1 -derived thymus cells 1 week after injection of bone marrow cells. A significant fraction of B6C3F 1 →C3Hf chimeras was shown to manifest a sudden loss of cellularity of spleens during the second week following injection of bone marrow cells even though cellularity was restored to the normal level within 1 week. The splenic mononuclear cells recovered from such chimeras almost invariably showed strong cytotoxicity against target cells expressing donor-type specific H-2 antigens (H-2/sup b/) when assesed by 51 Cr-release assay in vitro. The effector cells responsible for the observed anti-donor specific cytotoxicity were shown to be residual host-derived T cells. These results indicate strongly that residual host T cells could develop anti-donor specific cytotoxicity even after exposure to a supralethal dose (1050 R) of radiation and that the immunohematologic disturbances observed in shortterm F 1 to parent bone marrow chimeras (B6C3F 1 →C3Hf) were due to host-versus-graft reaction (HVGR) initiated by residual host T cells. The implication of these findings on the radiobiological nature of the residual T cells and the persistence of potentially anti-donor reactive T-cell clones in long-surviving allogeneic bone marrow chimeras was discussed

  3. Tannic acid and chromic chloride-induced binding of protein to red cells: a preliminary study of possible binding sites and reaction mechanisms.

    Science.gov (United States)

    Hunt, A F; Reed, M I

    1990-07-01

    The binding mechanisms and binding sites involved in the tannic acid and chromic chloride-induced binding of protein to red cells were investigated using the binding of IgA paraprotein to red cells as model systems. Inhibition studies of these model systems using amino acid homopolymers and compounds (common as red cell membrane constituents) suggest that the mechanisms involved are similar to those proposed for the conversion of hide or skin collagen to leather, as in commercial tanning. These studies also suggest that tannic acid-induced binding of IgA paraprotein to red cells involves the amino acid residues of L-arginine, L-lysine, L-histidine, and L-proline analogous to tanning with phenolic plant extracts. The amino acid residues of L-aspartate, L-glutamate and L-asparagine are involved in a similar manner in chronic chloride-induced binding of protein to red cells.

  4. Inhibitory effect of a tyrosine-fructose Maillard reaction product, 2,4-bis(p-hydroxyphenyl-2-butenal on amyloid-β generation and inflammatory reactions via inhibition of NF-κB and STAT3 activation in cultured astrocytes and microglial BV-2 cells

    Directory of Open Access Journals (Sweden)

    Choi Im Seup

    2011-10-01

    Full Text Available Abstract Background Amyloidogenesis is linked to neuroinflammation. The tyrosine-fructose Maillard reaction product, 2,4-bis(p-hydroxyphenyl-2-butenal, possesses anti-inflammatory properties in cultured macrophages, and in an arthritis animal model. Because astrocytes and microglia are responsible for amyloidogenesis and inflammatory reactions in the brain, we investigated the anti-inflammatory and anti-amyloidogenic effects of 2,4-bis(p-hydroxyphenyl-2-butenal in lipopolysaccharide (LPS-stimulated astrocytes and microglial BV-2 cells. Methods Cultured astrocytes and microglial BV-2 cells were treated with LPS (1 μg/ml for 24 h, in the presence (1, 2, 5 μM or absence of 2,4-bis(p-hydroxyphenyl-2-butenal, and harvested. We performed molecular biological analyses to determine the levels of inflammatory and amyloid-related proteins and molecules, cytokines, Aβ, and secretases activity. Nuclear factor-kappa B (NF-κB DNA binding activity was determined using gel mobility shift assays. Results We found that 2,4-bis(p-hydroxyphenyl-2-butenal (1, 2, 5 μM suppresses the expression of inducible nitric oxide synthase (iNOS and cyclooxygenase-2 (COX-2 as well as the production of nitric oxide (NO, reactive oxygen species (ROS, tumor necrosis factor-α (TNF-α, and interleukin-1β (IL-1β in LPS (1 μg/ml-stimulated astrocytes and microglial BV-2 cells. Further, 2,4-bis(p-hydroxyphenyl-2-butenal inhibited the transcriptional and DNA binding activity of NF-κB--a transcription factor that regulates genes involved in neuroinflammation and amyloidogenesis via inhibition of IκB degradation as well as nuclear translocation of p50 and p65. Consistent with the inhibitory effect on inflammatory reactions, 2,4-bis(p-hydroxyphenyl-2-butenal inhibited LPS-elevated Aβ42 levels through attenuation of β- and γ-secretase activities. Moreover, studies using signal transducer and activator of transcription 3 (STAT3 siRNA and a pharmacological inhibitor showed that 2

  5. Modeling of fluctuating reaction networks

    International Nuclear Information System (INIS)

    Lipshtat, A.; Biham, O.

    2004-01-01

    Full Text:Various dynamical systems are organized as reaction networks, where the population size of one component affects the populations of all its neighbors. Such networks can be found in interstellar surface chemistry, cell biology, thin film growth and other systems. I cases where the populations of reactive species are large, the network can be modeled by rate equations which provide all reaction rates within mean field approximation. However, in small systems that are partitioned into sub-micron size, these populations strongly fluctuate. Under these conditions rate equations fail and the master equation is needed for modeling these reactions. However, the number of equations in the master equation grows exponentially with the number of reactive species, severely limiting its feasibility for complex networks. Here we present a method which dramatically reduces the number of equations, thus enabling the incorporation of the master equation in complex reaction networks. The method is examplified in the context of reaction network on dust grains. Its applicability for genetic networks will be discussed. 1. Efficient simulations of gas-grain chemistry in interstellar clouds. Azi Lipshtat and Ofer Biham, Phys. Rev. Lett. 93 (2004), 170601. 2. Modeling of negative autoregulated genetic networks in single cells. Azi Lipshtat, Hagai B. Perets, Nathalie Q. Balaban and Ofer Biham, Gene: evolutionary genomics (2004), In press

  6. Type I Interferon Reaction to Viral Infection in Interferon-Competent, Immortalized Cell Lines from the African Fruit Bat Eidolon helvum

    Science.gov (United States)

    Biesold, Susanne E.; Ritz, Daniel; Gloza-Rausch, Florian; Wollny, Robert; Drexler, Jan Felix; Corman, Victor M.; Kalko, Elisabeth K. V.; Oppong, Samuel; Drosten, Christian; Müller, Marcel A.

    2011-01-01

    Bats harbor several highly pathogenic zoonotic viruses including Rabies, Marburg, and henipaviruses, without overt clinical symptoms in the animals. It has been suspected that bats might have evolved particularly effective mechanisms to suppress viral replication. Here, we investigated interferon (IFN) response, -induction, -secretion and -signaling in epithelial-like cells of the relevant and abundant African fruit bat species, Eidolon helvum (E. helvum). Immortalized cell lines were generated; their potential to induce and react on IFN was confirmed, and biological assays were adapted to application in bat cell cultures, enabling comparison of landmark IFN properties with that of common mammalian cell lines. E. helvum cells were fully capable of reacting to viral and artificial IFN stimuli. E. helvum cells showed highest IFN mRNA induction, highly productive IFN protein secretion, and evidence of efficient IFN stimulated gene induction. In an Alphavirus infection model, O'nyong-nyong virus exhibited strong IFN induction but evaded the IFN response by translational rather than transcriptional shutoff, similar to other Alphavirus infections. These novel IFN-competent cell lines will allow comparative research on zoonotic, bat-borne viruses in order to model mechanisms of viral maintenance and emergence in bat reservoirs. PMID:22140523

  7. Detection of alveolar rhabdomyosarcoma in pleural fluid with immunocytochemistry on cell block and determination of PAX/FKHR fusion mRNA by reverse transcription-polymerase chain reaction.

    Science.gov (United States)

    Sawangpanich, Ruchchadol; Larbcharoensub, Noppadol; Jinawath, Artit; Pongtippan, Atcharaporn; Anurathapan, Usanarat; Hongeng, Suradej

    2011-11-01

    Alveolar rhabdomyosarcoma is a primitive malignant round cell neoplasm, which shows skeletal muscle differentiation. Although their histopathologic and immunohistochemical findings are well known, the cytology, immunocytochemistry and molecular study on pleural effusion have not been well documented. To apply molecular method in the diagnosis and monitoring of alveolar rhabdomyosarcoma. The case of a 14-year-old Thai male, who presented with dyspnea and left pleural effusion. Computed tomography of the chest and abdomen showed a huge heterogeneous enhancing mass at the left retroperitoneum. Pleural fluid cytology showed malignant small round blue cells. Immunocytochemical stains on cell block material showed positive reactivity to vimentin, sarcomeric actin, desmin, MyoD1, myogenin, and CD56 in round cell tumor Reverse transcription-polymerase chain reaction (RT-PCR) demonstrated PAX/FKHR fusion transcript. The patient received chemotherapeutic regimen for advanced-stage rhabdomyosarcoma. Finally, he succumbed to the disease, thirteen months after the diagnosis. Immunocytochemistry on cell block in conjunction with determination of PAX/FKHR fusion mRNA by RT-PCR is a molecular method in the diagnosis and monitoring of alveolar rhabdomyosarcoma inpleural fluid.

  8. Adverse reactions to intravascularly administered contrast media

    International Nuclear Information System (INIS)

    Olin, T.

    1986-01-01

    A hypothesis is formulated about the mechanisms causing adverse reactions to contrast media. Contrast media act in two ways. They stimulate the mast cells to release histamine and leukotrienes, and they inhibit the enzymes which otherwise degrade leukotrienes. Thus individuals, especially those with a history of allergy, are easily exposed to undue amounts of leukotrienes and these are responsible for the adverse reactions. (orig.)

  9. Effects of induced energy deficiency on lactoferrin concentration in milk and the lactoferrin reaction of primary bovine mammary epithelial cells in vitro.

    Science.gov (United States)

    Danowski, K; Gross, J J; Meyer, H H D; Kliem, H

    2013-08-01

    A dietary energy restriction to 49% of total energy requirements was conducted with Red Holstein cows for three weeks in mid-lactation. At the last day of the restriction phase, primary bovine mammary epithelial cells (pbMEC) of eight restriction (RF) and seven control-fed (CF) cows were extracted out of one litre of milk and cultured. In their third passage, an immune challenge with the most prevalent, heat-inactivated mastitis pathogens Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was conducted. Lactoferrin (LF) was determined on gene expression and protein level. An enzyme-linked immunosorbent assay (ELISA) was developed to determine LF in milk samples taken twice weekly throughout the animal trial, beginning on day 20 pp (post-partum) until day 150 pp, in cell culture total protein and in cell culture supernatant. Milk LF increased throughout the lactation and decreased significantly during the induced energy deficiency in the RF group. At the beginning of realimentation, LF concentration increased immediately in the RF group and reached higher levels than before the induced deficit following the upward trend seen in the CF group. Cell culture data revealed higher levels (up to sevenfold up-regulation in gene expression) and significant higher LF protein concentration in the RF compared to the CF group cells. A further emphasized effect was found in E. coli compared to S. aureus exposed cells. The general elevated LF levels in the RF pbMEC group and the further increase owing to the immune challenge indicate an unexpected memory ability of milk-extracted mammary cells that were transposed into in vitro conditions and even displayed in the third passage of cultivation. The study confirms the suitability of the non-invasive milk-extracted pbMEC culture model to monitor the influence of feeding experiments on immunological situations in vivo. © 2012 Blackwell Verlag GmbH.

  10. A cuboctahedral platinum (Pt79) nanocluster enclosed by well defined facets favours di-sigma adsorption and improves the reaction kinetics for methanol fuel cells.

    Science.gov (United States)

    Mahata, Arup; Choudhuri, Indrani; Pathak, Biswarup

    2015-08-28

    The methanol dehydrogenation steps are studied very systematically on the (111) facet of a cuboctahedral platinum (Pt79) nanocluster enclosed by well-defined facets. The various intermediates formed during the methanol decompositions are adsorbed at the edge and bridge site of the facet either vertically (through C- and O-centres) or in parallel. The di-sigma adsorption (in parallel) on the (111) facet of the nanocluster is the most stable structure for most of the intermediates and such binding improves the interaction between the substrate and the nanocluster and thus the catalytic activity. The reaction thermodynamics, activation barrier, and temperature dependent reaction rates are calculated for all the successive methanol dehydrogenation steps to understand the methanol decomposition mechanism, and these values are compared with previous studies to understand the catalytic activity of the nanocluster. We find the catalytic activity of the nanocluster is excellent while comparing with any previous reports and the methanol dehydrogenation thermodynamics and kinetics are best when the intermediates are adsorbed in a di-sigma manner.

  11. Validation of tumor markers in central nervous system germ cell tumors by real-time reverse transcriptase polymerase chain reaction using formalin-fixed paraffin-embedded tissues.

    Science.gov (United States)

    Kim, Dowhan; Lee, Da Hye; Choi, Junjeong; Shim, Kyu Won; Kim, Se Hoon

    2013-01-01

    The therapeutic protocols for treatment of germinomas and non-germinomatous germ cell tumors (NGGCTs) are completely different, so it is important to distinguish pure germinomas from NGGCTs. As it can be difficult to diagnose by morphology alone, immunohisto-chemistry (IHC) has been widely used as an ancillary test to improve diagnostic accuracy. However, IHC has limitations due to the misinterpretation of results or the aberrant loss of immunoreactivity. However, real-time RT-PCR has certain advantages over IHC, including its quantitative nature. The aim of our study was to evaluate the usefulness of real-time RT-PCR on formalin-fixed paraffin-embedded (FFPE) tissue blocks for the diagnosis of germ cell tumors of the central nervous system. We selected eight markers of germ cell tumors using a literature search, and validated them using real-time RT-PCR. Among them, POU5F1, NANOG and TGFB2 were statistically significant (P=0.05) in multiple comparisons (MANOVA) of three groups (pure germinomas, mature teratomas and malignant germ cell tumors). Two-group (pure germinomas and NGGCTs) discriminant analysis achieved a 70.0% success rate in cross-validation. We concluded that real-time RT-PCR using FFPE tissue has adequate validating power comparable to IHC in the diagnosis of central nervous system germ cell tumors; therefore, when IHC is not available, not conclusive or not informative, RT-PCR is a potential alternative to a repeat biopsy.

  12. [Morpho-functional reaction of spleen natural killer cells and macrophages to melatonin administration to the animals kept on different illumination regimens].

    Science.gov (United States)

    Shatskikh, O A; Luzikova, E M

    2012-01-01

    The aim this investigation was to study the changes in the numbers of spleen CD57+ and CD68+ cells (natural killer cells and macrophages respectively) after melatonin administration to the animals kept on different illumination regimens. The experimental animals were given melatonin in dose of 0.03 mg per day for 2 and 4 weeks under conditions of natural illumination or artificial darkening. Spleen paraffin sections were stained using immunohistochemical methods for detection of CD57+ and CD68+ cells. It was shown that long-term administration of melatonin under conditions of natural illumination had an immunosuppressive effect, that was manifested by the depopulation of the marginal zones, white pulp and all the zones of the red pulp, parenchyma loosening and denudation of the reticular stroma of the organ. However, long-term hormone administration under conditions of artificial darkening had an immunostimulatory effect as evidenced by the increased inflow of immunocompetent cells into the spleen, their migration from the white pulp into the marginal zones and emigration into peripheral blood flow, concomitant with the increase in the number of lymphoid nodules. The number of CD57+ and CD68+ cells was increased in splenic periarterial lymphoid sheaths and decreased in B-dependent zones of the organ.

  13. Label-free electrochemiluminescence biosensor for ultrasensitive detection of telomerase activity in HeLa cells based on extension reaction and intercalation of Ru(phen)3 (2.).

    Science.gov (United States)

    Lin, Yue; Yang, Linlin; Yue, Guiyin; Chen, Lifen; Qiu, Bin; Guo, Longhua; Lin, Zhenyu; Chen, Guonan

    2016-10-01

    Telomerase is one of the most common markers of human malignant tumors, such as uterine, stomach, esophageal, breast, colorectal, laryngeal squamous cell, thyroid, bladder, and so on. It is necessary to develop some sensitive but convenient detection methods for telomerase activity determination. In this study, a label-free and ultrasensitive electrochemiluminescence (ECL) biosensor has been fabricated to detect the activity of telomerase extracted from HeLa cells. Thiolated telomerase substrate (TS) primer was immobilized on the gold electrode surface through gold-sulfur (Au-S) interaction and then elongated by telomerase specifically. Then, it was hybridized with complementary DNA to form double-stranded DNA (dsDNA) fragments on the electrode surface, and Ru(phen)3 (2+) has been intercalated into the dsDNA grooves to act as the ECL probe. The enhanced ECL intensity has a linear relationship with the number of HeLa cells in the range of 5∼5000 and with a detection limit of 2 HeLa cells. The proposed ECL biosensor has high specificity to telomerase in the presence of common interferents. The relative standard deviations (RSDs) were HeLa cells. The proposed method provides a convenient approach for telomerase-related cancer screening or diagnosis.

  14. The utilization of adenosine triphosphate in rat mast cells during histamine release induced by anaphylactic reaction and compound 48/80

    DEFF Research Database (Denmark)

    Johansen, Torben; Chakravarty, N

    1975-01-01

    of ATP synthesis while a large part of the histamine release remained unaffected-a decrease in the ATP content could be demonstrated in close time relation to both anaphylactic and compound 48/80-induced histamine release. The observations indicate an increased utilization of ATP in mast cells during...

  15. Significant promotion effect of carbon nanotubes on the electrocatalytic activity of supported Pd NPs for ethanol oxidation reaction of fuel cells: the role of inner tubes.

    Science.gov (United States)

    Zhang, Jin; Cheng, Yi; Lu, Shanfu; Jia, Lichao; Shen, Pei Kang; Jiang, San Ping

    2014-11-18

    The inner tubes of carbon nanotubes (CNTs) have a significant promotion effect on the electrocatalytic activity of Pd nanoparticles (NPs) for the ethanol oxidation of direct alcohol fuel cells (DAFCs) and Pd NPs supported on CNTs with 3-7 walls show a much higher activity as compared to that supported on typical single-walled and multi-walled CNTs.

  16. Electro-catalytic activity of multiwall carbon nanotube-metal (Pt or Pd) nanohybrid materials synthesized using microwave-induced reactions and their possible use in fuel cells.

    Science.gov (United States)

    V, Lakshman Kumar; Ntim, Susana Addo; Sae-Khow, Ornthida; Janardhana, Chelli; Lakshminarayanan, V; Mitra, Somenath

    2012-11-30

    Microwave induced reactions for immobilizing platinum and palladium nanoparticles on multiwall carbon nanotubes are presented. The resulting hybrid materials were used as catalysts for direct methanol, ethanol and formic acid oxidation in acidic as well as alkaline media. The electrodes are formed by simply mixing the hybrids with graphite paste, thus using a relatively small quantity of the precious metal. We report Tafel slopes and apparent activation energies at different potentials and temperatures. Ethanol electro-oxidation with the palladium hybrid showed an activation energy of 7.64 kJmol(-1) which is lower than those observed for other systems. This system is economically attractive because Pd is significantly less expensive than Pt and ethanol is fast evolving as a commercial biofuel.

  17. Electro-catalytic activity of multiwall carbon nanotube-metal (Pt or Pd) nanohybrid materials synthesized using microwave-induced reactions and their possible use in fuel cells

    Science.gov (United States)

    V, Lakshman Kumar; Ntim, Susana Addo; Sae-Khow, Ornthida; Janardhana, Chelli; Lakshminarayanan, V.; Mitra, Somenath

    2012-01-01

    Microwave induced reactions for immobilizing platinum and palladium nanoparticles on multiwall carbon nanotubes are presented. The resulting hybrid materials were used as catalysts for direct methanol, ethanol and formic acid oxidation in acidic as well as alkaline media. The electrodes are formed by simply mixing the hybrids with graphite paste, thus using a relatively small quantity of the precious metal. We report Tafel slopes and apparent activation energies at different potentials and temperatures. Ethanol electro-oxidation with the palladium hybrid showed an activation energy of 7.64 kJmol−1 which is lower than those observed for other systems. This system is economically attractive because Pd is significantly less expensive than Pt and ethanol is fast evolving as a commercial biofuel. PMID:23118490

  18. Reduction of Pt{sup 2+} species in model Pt–CeO{sub 2} fuel cell catalysts upon reaction with methanol

    Energy Technology Data Exchange (ETDEWEB)

    Neitzel, Armin [Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen (Germany); Johánek, Viktor [Charles University, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, V Holešovičkách 2, 18000 Prague (Czech Republic); Lykhach, Yaroslava, E-mail: yaroslava.lykhach@fau.de [Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen (Germany); Skála, Tomáš; Tsud, Nataliya; Vorokhta, Mykhailo; Matolín, Vladimír [Charles University, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, V Holešovičkách 2, 18000 Prague (Czech Republic); Libuda, Jörg [Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen (Germany); Erlangen Catalysis Resource Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen (Germany)

    2016-11-30

    Highlights: • Pt{sup 2+} species are reduced upon reaction with methanol. • Reduction of one Pt{sup 2+} requires presence of two oxygen vacancies. • Reduction of Pt{sup 2+} species leads to formation of ultra-small Pt particles. • Ultra-small Pt particles (around 25 atoms or less) are resistant to sintering. - Abstract: The stability of atomically dispersed Pt{sup 2+} species on the surface of nanostructured CeO{sub 2} films during the reaction with methanol has been investigated by means of synchrotron radiation photoelectron spectroscopy and resonant photoemission spectroscopy. The isolated Pt{sup 2+} species were prepared at low Pt concentration in Pt–CeO{sub 2} film. Additionally, Pt{sup 2+} species coexisting with metallic Pt particles were prepared at high Pt concentration. We found that adsorption of methanol yields similar decomposition products regardless of Pt concentration in Pt–CeO{sub 2} films. A small number of oxygen vacancies formed during the methanol decomposition can be replenished in the Pt–CeO{sub 2} film with low Pt concentration by diffusion of oxygen from the bulk. In the presence of supported Pt particles, a higher number of oxygen vacancies leads to a partial reduction of the Pt{sup 2+} species. The isolated Pt{sup 2+} species are reduced under rather strongly reducing conditions only, i.e. during annealing under continuous exposure to methanol. Reduction of isolated Pt{sup 2+} species results in the formation of ultra-small Pt particles containing around 25 atoms per particle or less. Such ultra-small Pt particles demonstrate excellent stability against sintering during annealing of Pt–CeO{sub 2} film with low Pt concentration under reducing conditions.

  19. A study of the frequency of infection of peripheral blood mononuclear cells of chronic hepatitis B virus carriers using the polymerase chain reaction and hybridization analysis

    Energy Technology Data Exchange (ETDEWEB)

    Yap, S F; Wong, P W; Goh, K L; Wong, N W [Malaya Univ., Kuala Lumpur (Malaysia). Depts. of Pathology and Dept. of Medicine

    1994-05-01

    Peripheral blood mononuclear cells (PBMCs) from 100 consecutive chronic carriers of the Hepatitis B virus (HBV) were analysed to determine the frequency of infection of the PBMCs. Cells were isolated using a ficoll gradient and DNA extracted by phenol following an overnight incubation with proteinase K and tween-20. Target nucleic acid were amplified using a set of primers spanning the S region of the viral genome between nucleotides 79 and 761. Following amplification, the samples were gel electrophoresed and the fragments visualized by ethidium bromide staining. The presence of a fragment of about 720 bp was taken as indicative of specific amplification of the HBV nucleic acid sequences. Specificity of amplification was confirmed by hybridization analysis using virus specific probes. Thirty-six out of 41 (87.8%) HBeAg seropositive cases and 15/54 (27.8%) anti-HBe positive cases had HBV DNA detectable by gel electrophoresis. Following hybridization all carriers were found to harbour the virus in their mononuclear cells. The sensitivity using ethidium bromide staining to visualize the amplified sequences was about 1 pg. With hybridization analysis, sensitivity was increased about 10{sup 5}-fold. (author). 12 refs, 1 fig., 1 tab.

  20. Treatment and Managing Reactions

    Science.gov (United States)

    ... of reactions. Learn more here. Milk Egg Peanut Tree Nuts Soy Wheat Fish Shellfish Sesame Other Food ... a severe reaction. Consider wearing an emergency medical identification (e.g., bracelet, other jewelry). What to Read ...

  1. Microfluidic chemical reaction circuits

    Science.gov (United States)

    Lee, Chung-cheng [Irvine, CA; Sui, Guodong [Los Angeles, CA; Elizarov, Arkadij [Valley Village, CA; Kolb, Hartmuth C [Playa del Rey, CA; Huang, Jiang [San Jose, CA; Heath, James R [South Pasadena, CA; Phelps, Michael E [Los Angeles, CA; Quake, Stephen R [Stanford, CA; Tseng, Hsian-rong [Los Angeles, CA; Wyatt, Paul [Tipperary, IE; Daridon, Antoine [Mont-Sur-Rolle, CH

    2012-06-26

    New microfluidic devices, useful for carrying out chemical reactions, are provided. The devices are adapted for on-chip solvent exchange, chemical processes requiring multiple chemical reactions, and rapid concentration of reagents.

  2. Preequilibrium Nuclear Reactions

    International Nuclear Information System (INIS)

    Strohmaier, B.

    1988-01-01

    After a survey on existing experimental data on precompound reactions and a description of preequilibrium reactions, theoretical models and quantum mechanical theories of preequilibrium emission are presented. The 25 papers of this meeting are analyzed separately

  3. Managing Your Emotional Reactions

    Science.gov (United States)

    ... Videos for Educators Search English Español Managing Your Emotional Reactions KidsHealth / For Teens / Managing Your Emotional Reactions ... Think about what you might do next time. Emotions 101 The skills we use to manage our ...

  4. Heavy ion transfer reactions

    Indian Academy of Sciences (India)

    array (CLARA), extensive investigations of nuclear structure and reaction dynamics have been carried out. In the present paper aspects of these studies will be presented, focussing more closely on the reaction mechanism, in particular on the ...

  5. Allergoid-specific T-cell reaction as a measure of the immunological response to specific immunotherapy (SIT) with a Th1-adjuvanted allergy vaccine.

    Science.gov (United States)

    von Baehr, V; Hermes, A; von Baehr, R; Scherf, H P; Volk, H D; Fischer von Weikersthal-Drachenberg, K J; Woroniecki, S

    2005-01-01

    Specific immunotherapy (SIT) is believed to modulate CD4+ T-helper cells. In order to improve safety, SIT vaccines are often formulated with allergoids (chemically modified allergens). Interaction between T-cells and allergoids is necessary to influence cellular cytokine expression. There have been few reports on identification the early cellular effects of SIT. Patients allergic to grass and/or mugwort pollen (n= 21) were treated with a 4-shot allergy vaccine (Pollinex Quattro) containing appropriate allergoids (grass/rye and/or mugwort) adsorbed to L-tyrosine plus a Th1 adjuvant, monophosphoryl lipid A (MPL). Fourteen grass-allergic patients served as untreated controls. Using the peripheral blood mononuclear cells of these patients, an optimized lymphocyte transformation test (LTT) was employed to monitor the in vitro proliferative response of T-cells to an allergoid challenge (solubilised Pollinex Quattro) before the first and last injection and then 2 and 20 weeks after the final injection. Control challenges utilised preparations of a similar pollen vaccine without the adjuvant MPL and a tree pollen vaccine with and without MPL. The LTT showed increased LTT stimulation indices (SI) in 17/20 SIT patients when the solublised vaccine preparation was used as a challenge before the last injection and 2 weeks after, in comparison to pre-treatment levels. Twenty weeks after therapy, the SI decreased to baseline level. A vaccine challenge without MPL gave lower SI levels. A challenge of a clinically inappropriate tree allergoid vaccine gave no response, and a nontreated group also showed no response. Following a short-course SIT adjuvated with MPL, challenges of allergoids were shown to activate allergen-specific T cells in vitro. There was an additional stimulating effect when the challenge was in combination with MPL. There were no non-specific effects of MPL, shown by the tree allergoid/MPL control. The timing of the response was closely correlated to the

  6. Chemical transport reactions

    CERN Document Server

    Schäfer, Harald

    2013-01-01

    Chemical Transport Reactions focuses on the processes and reactions involved in the transport of solid or liquid substances to form vapor phase reaction products. The publication first offers information on experimental and theoretical principles and the transport of solid substances and its special applications. Discussions focus on calculation of the transport effect of heterogeneous equilibria for a gas motion between equilibrium spaces; transport effect and the thermodynamic quantities of the transport reaction; separation and purification of substances by means of material transport; and

  7. Thermonuclear reaction rates. III

    International Nuclear Information System (INIS)

    Harris, M.J.; Fowler, W.A.; Caughlan, G.R.; Zimmerman, B.A.

    1983-01-01

    Stellar thermonuclear reaction rates are revised and updated, adding a number of new important reaction rates. Several reactions with large negative Q-values are included, and examples of them are discussed. The importance of the decay rates for Mg-26(p,n) exp 26 Al and Al-26(n,p) exp 26 Mg for stellar studies is emphasized. 19 references

  8. Maillard Reaction: review

    Directory of Open Access Journals (Sweden)

    Júlia d'Almeida Francisquini

    2017-11-01

    Full Text Available Maillard reaction is an important subject of study in food science and technology and different areas of knowledge are involved such as chemistry, food engineering, nutrition and food technology. The objective of this paper is to present the basic concepts of the Maillard reaction, such as the reaction stages, the main compounds producced and some technological consequences for dairy products.

  9. Resonant thermonuclear reaction rate

    International Nuclear Information System (INIS)

    Haubold, H.J.; Mathai, A.M.

    1986-01-01

    Basic physical principles for the resonant and nonresonant thermonuclear reaction rates are applied to find their standard representations for nuclear astrophysics. Closed-form representations for the resonant reaction rate are derived in terms of Meijer's G-function. Analytic representations of the resonant and nonresonant nuclear reaction rates are compared and the appearance of Meijer's G-function is discussed in physical terms

  10. Selective amplification of T-cell receptor variable region species is demonstrable but not essential in early lesions of psoriasis vulgaris: analysis by anchored polymerase chain reaction and hypervariable region size spectratyping.

    Science.gov (United States)

    Vekony, M A; Holder, J E; Lee, A J; Horrocks, C; Eperon, I C; Camp, R D

    1997-07-01

    Several groups have investigated the role of T cells in the pathogenesis of psoriasis by determination of T-cell receptor (TCR) B-chain variable (V) region usage, both in chronic plaque (psoriasis vulgaris) and guttate forms, with various results. Because there are no data on TCR expression in early psoriasis vulgaris, when specific cellular immune events may be expected to be most pronounced, we have analyzed early lesions (less than 3 wk old) of ten patients, with highly reproducible results. We have developed a highly controlled anchored polymerase chain reaction (PCR) method in which TCR beta chain species are all amplified with the same primer pair and products are quantified by dot blot hybridization with BV family-specific oligonucleotide probes. Overexpression of certain TCR BV genes was observed in the majority of lesional biopsies, but in samples in which the expanded BV family formed more than 10% of total lesional BV (half of the samples analyzed), BV2 and BV6 predominated. The consistency of overexpression of these BV species between patients was much less than in previous studies of TCRBV usage in established chronic plaque psoriasis lesions. Complementarity-determining region 3 (CDR3) size spectratyping demonstrated evidence for selective clonal T cell accumulation in less than half of the lesional samples showing BV expansion. These results indicate that selective amplification of TCRBV species occurs in early psoriasis vulgaris but is not essential to the pathogenic process and may be more important in the maintenance or expansion of chronic lesions.

  11. [Effects of transient receptor potential melastatin 8 cation channels on inflammatory reaction induced by cold temperatures in human airway epithelial cells].

    Science.gov (United States)

    Li, Min-chao; Perelman, Juliy M; Kolosov, Victor P; Zhou, Xiang-dong

    2011-10-01

    To explore the role of transient receptor potential melastatin 8 cation channels (TRPM8) in cold-induced production of inflammatory factors in airway epithelial cells and related signal transduction mechanism. The 16HBE human airway epithelial cells were stimulated with cold temperature (18°C). In intervention experiments, cells were pretreated with TRPM8 channel antagonist BCTC, protein kinase C (PKC) specific inhibitor calphostin C and transfected with TRPM8 shRNA or control shRNA respectively, and thereafter cold stimulation was applied. Cells were divided into 6 groups: a control group (incubated at 37°C), a cold stimulation group, a cold stimulation + BCTC group, a cold stimulation + TRPM8 shRNA group, a cold stimulation + control shRNA group, a cold stimulation + calphostin C group. Western blot was performed to show the extent of knockdown in TRPM8 protein expression in the TRPM8 shRNA transfected cells. Dynamics of relative concentration of intracellular Ca(2+) in the former 5 groups were measured by calcium imaging techniques. Images were taken at one frame per 10 seconds. The levels of interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-α mRNA and protein were detected by real-time PCR and ELISA respectively. The highest relative concentration of intracellular calcium in cold stimulation group (2.36 ± 0.24) was higher than that of control group (1.01 ± 0.02) (t = 12.52, P cold stimulation group (t = 6.69 and 9.12, all P cold stimulation group[0.66 ± 0.16, 0.77 ± 0.15, 0.73 ± 0.09 and (92 ± 13) ng/L, (125 ± 22) ng/L, (88 ± 12) ng/L ] were significantly higher than those in control group [0.37 ± 0.08, 0.32 ± 0.07, 0.48 ± 0.10 and (52 ± 8) ng/L, (50 ± 9) ng/L, (61 ± 8) ng/L] (t = 3.20 - 6.26, all P cold stimulation + BCTC group [0.42 ± 0.09, 0.52 ± 0.13, 0.52 ± 0.12 and (72 ± 8) ng/L, (92 ± 14) ng/L, (68 ± 11) ng/L], cold stimulation + TRPM8 shRNA group [0.41 ± 0.10, 0.49 ± 0.08, 0.50 ± 0.08 and (60 ± 12) ng/L, (89 ± 14) ng

  12. Determination of low concentrations of iron, arsenic, selenium, cadmium, and other trace elements in natural samples using an octopole collision/reaction cell equipped quadrupole-inductively coupled plasma mass spectrometer.

    Science.gov (United States)

    Dial, Angela R; Misra, Sambuddha; Landing, William M

    2015-04-30

    Accurate determination of trace metals has many applications in environmental and life sciences, such as constraining the cycling of essential micronutrients in biological production and employing trace metals as tracers for anthropogenic pollution. Analysis of elements such as Fe, As, Se, and Cd is challenged by the formation of polyatomic mass spectrometric interferences, which are overcome in this study. We utilized an Octopole Collision/Reaction Cell (CRC)-equipped Quadrupole-Inductively Coupled Plasma Mass Spectrometer for the rapid analysis of small volume samples (~250 μL) in a variety of matrices containing HNO3 and/or HCl. Efficient elimination of polyatomic interferences was demonstrated by the use of the CRC in Reaction Mode (RM; H2 gas) and in Collision-Reaction Mode (CRM; H2 and He gas), in addition to hot plasma (RF power 1500 W) and cool plasma (600 W) conditions. It was found that cool plasma conditions with RM achieved the greatest signal sensitivity while maintaining low detection limits (i.e. (56) Fe in 0.44 M HNO3 has a sensitivity of 160,000 counts per second (cps)-per-1 µg L(-1) and a limit of detection (LoD) of 0.86 ng L(-1) ). The average external precision was ≤ ~10% for minor (≤10 µg L(-1) ) elements measured in a 1:100 dilution of NIST 1643e and for iron in rainwater samples under all instrumental operating conditions. An improved method has been demonstrated for the rapid multi-element analysis of trace metals that are challenged by polyatomic mass spectrometric interferences, with a focus on (56) Fe, (75) As, (78) Se and (111) Cd. This method can contribute to aqueous environmental geochemistry and chemical oceanography, as well as other fields such as forensic chemistry, agriculture, food chemistry, and pharmaceutical sciences. Copyright © 2015 John Wiley & Sons, Ltd.

  13. Biomarkers of adverse drug reactions.

    Science.gov (United States)

    Carr, Daniel F; Pirmohamed, Munir

    2018-02-01

    Adverse drug reactions can be caused by a wide range of therapeutics. Adverse drug reactions affect many bodily organ systems and vary widely in severity. Milder adverse drug reactions often resolve quickly following withdrawal of the casual drug or sometimes after dose reduction. Some adverse drug reactions are severe and lead to significant organ/tissue injury which can be fatal. Adverse drug reactions also represent a financial burden to both healthcare providers and the pharmaceutical industry. Thus, a number of stakeholders would benefit from development of new, robust biomarkers for the prediction, diagnosis, and prognostication of adverse drug reactions. There has been significant recent progress in identifying predictive genomic biomarkers with the potential to be used in clinical settings to reduce the burden of adverse drug reactions. These have included biomarkers that can be used to alter drug dose (for example, Thiopurine methyltransferase (TPMT) and azathioprine dose) and drug choice. The latter have in particular included human leukocyte antigen (HLA) biomarkers which identify susceptibility to immune-mediated injuries to major organs such as skin, liver, and bone marrow from a variety of drugs. This review covers both the current state of the art with regard to genomic adverse drug reaction biomarkers. We also review circulating biomarkers that have the potential to be used for both diagnosis and prognosis, and have the added advantage of providing mechanistic information. In the future, we will not be relying on single biomarkers (genomic/non-genomic), but on multiple biomarker panels, integrated through the application of different omics technologies, which will provide information on predisposition, early diagnosis, prognosis, and mechanisms. Impact statement • Genetic and circulating biomarkers present significant opportunities to personalize patient therapy to minimize the risk of adverse drug reactions. ADRs are a significant heath issue

  14. Cell-secreted flavins bound to membrane cytochromes dictate electron transfer reactions to surfaces with diverse charge and pH.

    Science.gov (United States)

    Okamoto, Akihiro; Kalathil, Shafeer; Deng, Xiao; Hashimoto, Kazuhito; Nakamura, Ryuhei; Nealson, Kenneth H

    2014-07-11

    The variety of solid surfaces to and from which microbes can deliver electrons by extracellular electron transport (EET) processes via outer-membrane c-type cytochromes (OM c-Cyts) expands the importance of microbial respiration in natural environments and industrial applications. Here, we demonstrate that the bifurcated EET pathway of OM c-Cyts sustains the diversity of the EET surface in Shewanella oneidensis MR-1 via specific binding with cell-secreted flavin mononucleotide (FMN) and riboflavin (RF). Microbial current production and whole-cell differential pulse voltammetry revealed that RF and FMN enhance EET as bound cofactors in a similar manner. Conversely, FMN and RF were clearly differentiated in the EET enhancement by gene-deletion of OM c-Cyts and the dependency of the electrode potential and pH. These results indicate that RF and FMN have specific binding sites in OM c-Cyts and highlight the potential roles of these flavin-cytochrome complexes in controlling the rate of electron transfer to surfaces with diverse potential and pH.

  15. Insights into the mechanisms on chemical reactions: reaction paths for chemical reactions

    International Nuclear Information System (INIS)

    Dunning, T.H. Jr.; Rosen, E.; Eades, R.A.

    1987-01-01

    We report reaction paths for two prototypical chemical reactions: Li + HF, an electron transfer reaction, and OH + H 2 , an abstraction reaction. In the first reaction we consider the connection between the energetic terms in the reaction path Hamiltonian and the electronic changes which occur upon reaction. In the second reaction we consider the treatment of vibrational effects in chemical reactions in the reaction path formalism. 30 refs., 9 figs

  16. Significance of detecting circulating hepatocellular carcinoma cells in peripheral blood of hepatocellular carcinoma patients by nested reverse transcription-polymerase chain reaction and its clinical value: a retrospective study.

    Science.gov (United States)

    Liu, Yang; Wang, Yue-ru; Wang, Long; Song, Rui-mei; Zhou, Bo; Song, Zhen-shun

    2014-01-01

    Circulating hepatocellular carcinoma cells may be detected by reverse transcription-polymerase chain reaction. We investigated the relationship between circulating hepatocellular carcinoma cells and hepatoma patient survival after different managements and survival periods. Peripheral vein blood (5 ml) samples were obtained from 113 patients with hepatocellular carcinoma and from 33 control subjects (9 with liver cirrhosis after hepatitis B, 14 with chronic hepatitis B, 10 healthy individuals) between January 1, 2009, and December 31, 2013. To detect circulating hepatocellular carcinoma cells in peripheral blood, alpha-fetoprotein messenger RNA was amplified from total RNA extracted from whole blood by reverse transcription-polymerase chain reaction. Alpha-fetoprotein messenger RNA was detected in 59 blood samples from the hepatocellular carcinoma patients (59/113, 52.2%). In contrast, there were no clinical control subjects whose samples showed detectable alpha-fetoprotein messenger RNA. The presence of alpha-fetoprotein messenger RNA in blood seemed to be correlated with the stage (by TNM classification) of hepatocellular carcinoma, serum alpha-fetoprotein value, and the presence of intrahepatic metastasis, portal vein thrombosis, tumor diameter and/or distant metastasis. In addition, alpha-fetoprotein messenger RNA was detected in the blood of 25 patients showing distant metastasis at extrahepatic organs (100%), in contrast to 32 of 88 cases without metastasis (36.4%). All the patients with hepatocellular carcinoma were followed. Seventeen patients with resection of a T 2 stage hepatocellular carcinoma had a survival of 3.2 years after surgical management, 38 cases with resection of a T3 stage hepatocellular carcinoma had a 1.3-year survival, and only 37 cases with T4 stage disease after different treatments except surgery survived for 0.6 years (P <0.01). The presence of alpha-fetoprotein messenger RNA in peripheral blood may be an indicator of circulating

  17. The effect of the series resistance in dye-sensitized solar cells explored by electron transport and back reaction using electrical and optical modulation techniques

    International Nuclear Information System (INIS)

    Liu Weiqing; Hu Linhua; Dai Songyuan; Guo Lei; Jiang Nianquan; Kou Dongxing

    2010-01-01

    The influence of the series resistance on the electron transport and recombination processes in dye-sensitized solar cells (DSC) has been investigated. The series resistances induced by some parts of DSC, such as the transparent conductive oxide (TCO), the electrolyte layer and the counter electrode, influence the performance of DSC. By combining three frequency-domain techniques, specifically electrochemical impedance spectroscopy (EIS), intensity modulated photocurrent spectroscopy (IMPS) and intensity modulated photovoltage spectroscopy (IMVS), we studied the relationship between the series resistance and the dynamic response of DSC. The results show that the series resistance induced by the TCO or counter electrode predominantly affects the electron transport under short circuit conditions and has no significant influence on the recombination under open circuit conditions. However, the resistance related to the electrolyte layer not only limits the carrier transport but also influences the recombination. Possible reasons for the influence of the series resistance on the electron transport and recombination processes in DSC are also discussed.

  18. Real rock-microfluidic flow cell: A test bed for real-time in situ analysis of flow, transport, and reaction in a subsurface reactive transport environment.

    Science.gov (United States)

    Singh, Rajveer; Sivaguru, Mayandi; Fried, Glenn A; Fouke, Bruce W; Sanford, Robert A; Carrera, Martin; Werth, Charles J

    2017-09-01

    Physical, chemical, and biological interactions between groundwater and sedimentary rock directly control the fundamental subsurface properties such as porosity, permeability, and flow. This is true for a variety of subsurface scenarios, ranging from shallow groundwater aquifers to deeply buried hydrocarbon reservoirs. Microfluidic flow cells are now commonly being used to study these processes at the pore scale in simplified pore structures meant to mimic subsurface reservoirs. However, these micromodels are typically fabricated from glass, silicon, or polydimethylsiloxane (PDMS), and are therefore incapable of replicating the geochemical reactivity and complex three-dimensional pore networks present in subsurface lithologies. To address these limitations, we developed a new microfluidic experimental test bed, herein called the Real Rock-Microfluidic Flow Cell (RR-MFC). A porous 500μm-thick real rock sample of the Clair Group sandstone from a subsurface hydrocarbon reservoir of the North Sea was prepared and mounted inside a PDMS microfluidic channel, creating a dynamic flow-through experimental platform for real-time tracking of subsurface reactive transport. Transmitted and reflected microscopy, cathodoluminescence microscopy, Raman spectroscopy, and confocal laser microscopy techniques were used to (1) determine the mineralogy, geochemistry, and pore networks within the sandstone inserted in the RR-MFC, (2) analyze non-reactive tracer breakthrough in two- and (depth-limited) three-dimensions, and (3) characterize multiphase flow. The RR-MFC is the first microfluidic experimental platform that allows direct visualization of flow and transport in the pore space of a real subsurface reservoir rock sample, and holds potential to advance our understandings of reactive transport and other subsurface processes relevant to pollutant transport and cleanup in groundwater, as well as energy recovery. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Quantitative assessment of hematopoietic chimerism by quantitative real-time polymerase chain reaction of sequence polymorphism systems after hematopoietic stem cell transplantation.

    Science.gov (United States)

    Qin, Xiao-ying; Li, Guo-xuan; Qin, Ya-zhen; Wang, Yu; Wang, Feng-rong; Liu, Dai-hong; Xu, Lan-ping; Chen, Huan; Han, Wei; Wang, Jing-zhi; Zhang, Xiao-hui; Li, Jin-lan; Li, Ling-di; Liu, Kai-yan; Huang, Xiao-jun

    2011-08-01

    Analysis of changes in recipient and donor hematopoietic cell origin is extremely useful to monitor the effect of hematopoietic stem cell transplantation (HSCT) and sequential adoptive immunotherapy by donor lymphocyte infusions. We developed a sensitive, reliable and rapid real-time PCR method based on sequence polymorphism systems to quantitatively assess the hematopoietic chimerism after HSCT. A panel of 29 selected sequence polymorphism (SP) markers was screened by real-time PCR in 101 HSCT patients with leukemia and other hematological diseases. The chimerism kinetics of bone marrow samples of 8 HSCT patients in remission and relapse situations were followed longitudinally. Recipient genotype discrimination was possible in 97.0% (98 of 101) with a mean number of 2.5 (1-7) informative markers per recipient/donor pair. Using serial dilutions of plasmids containing specific SP markers, the linear correlation (r) of 0.99, the slope between -3.2 and -3.7 and the sensitivity of 0.1% were proved reproducible. By this method, it was possible to very accurately detect autologous signals in the range from 0.1% to 30%. The accuracy of the method in the very important range of autologous signals below 5% was extraordinarily high (standard deviation real-time PCR method over short tandem repeat PCR chimerism assays is the absence of PCR competition and plateau biases, with demonstrated greater sensitivity and linearity. Finally, we prospectively analyzed bone marrow samples of 8 patients who received allografts and presented the chimerism kinetics of remission and relapse situations that illustrated the sensitivity level and the promising clinical application of this method. This SP-based real-time PCR assay provides a rapid, sensitive, and accurate quantitative assessment of mixed chimerism that can be useful in predicting graft rejection and early relapse.

  20. Expression of the Long Intergenic Non-Protein Coding RNA 665 (LINC00665) Gene and the Cell Cycle in Hepatocellular Carcinoma Using The Cancer Genome Atlas, the Gene Expression Omnibus, and Quantitative Real-Time Polymerase Chain Reaction.

    Science.gov (United States)

    Wen, Dong-Yue; Lin, Peng; Pang, Yu-Yan; Chen, Gang; He, Yun; Dang, Yi-Wu; Yang, Hong

    2018-05-05

    BACKGROUND Long non-coding RNAs (lncRNAs) have a role in physiological and pathological processes, including cancer. The aim of this study was to investigate the expression of the long intergenic non-protein coding RNA 665 (LINC00665) gene and the cell cycle in hepatocellular carcinoma (HCC) using database analysis including The Cancer Genome Atlas (TCGA), the Gene Expression Omnibus (GEO), and quantitative real-time polymerase chain reaction (qPCR). MATERIAL AND METHODS Expression levels of LINC00665 were compared between human tissue samples of HCC and adjacent normal liver, clinicopathological correlations were made using TCGA and the GEO, and qPCR was performed to validate the findings. Other public databases were searched for other genes associated with LINC00665 expression, including The Atlas of Noncoding RNAs in Cancer (TANRIC), the Multi Experiment Matrix (MEM), Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and protein-protein interaction (PPI) networks. RESULTS Overexpression of LINC00665 in patients with HCC was significantly associated with gender, tumor grade, stage, and tumor cell type. Overexpression of LINC00665 in patients with HCC was significantly associated with overall survival (OS) (HR=1.47795%; CI: 1.046-2.086). Bioinformatics analysis identified 469 related genes and further analysis supported a hypothesis that LINC00665 regulates pathways in the cell cycle to facilitate the development and progression of HCC through ten identified core genes: CDK1, BUB1B, BUB1, PLK1, CCNB2, CCNB1, CDC20, ESPL1, MAD2L1, and CCNA2. CONCLUSIONS Overexpression of the lncRNA, LINC00665 may be involved in the regulation of cell cycle pathways in HCC through ten identified hub genes.

  1. A comparison of the cytotoxicity and proinflammatory cytokine production of EndoSequence root repair material and ProRoot mineral trioxide aggregate in human osteoblast cell culture using reverse-transcriptase polymerase chain reaction.

    Science.gov (United States)

    Ciasca, Maria; Aminoshariae, Anita; Jin, Ge; Montagnese, Thomas; Mickel, Andre

    2012-04-01

    The purpose of this study was to compare the cytotoxicity and cytokine expression profiles of EndoSequence Root Repair Material (ERRM; Brasseler, Savannah, GA) putty, ERRM flowable, and ProRoot mineral trioxide aggregate (MTA; Dentsply Tulsa Dental, Johnson City, TN) using osteoblast cells (MG-63). Four millimeters in diameter of each material was placed in the center of a 6-well culture plate, and a 2-mL suspension (10(5) cells/mL) of human osteoblasts was seeded in each well. Photomicrograph images were used to evaluate cytotoxicity as evidenced by the lack of osteoblast cell growth in relation to the materials with AH-26 (Dentsply Tulsa Dental) as the positive control. In addition, reverse-transcriptase polymerase chain reaction (RT-PCR) was used to evaluate the expression of interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor-α (TNF-α). Cytokine expression of MG-63 cells upon lipopolysaccharide treatment was used as controls. RT-PCR results were normalized by the expression of the housekeeping gene β-actin and were used to measure cytokine expression. Statistical analysis was performed using analysis of variance. Results showed that ERRM putty and MTA exhibited minimal levels of cytotoxicity; however, ERRM was slightly more cytotoxic although not statistically significant. The expression of IL-1β, IL-6, and IL-8 was detected in all samples with minimal TNF-α expression. We concluded that ERRM and MTA showed similar cytotoxicity and cytokine expressions. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  2. STUDIES ON ENDOTHELIAL REACTIONS

    Science.gov (United States)

    Foot, Nathan Chandler

    1923-01-01

    operative. On the other hand, there may be an increase in the phagocytic activity of the endothelium of the sinusoids which might take up more bacteria under these changed conditions. Several investigators have claimed, recently, that there is an increased activity of the liver endothelium following splenectomy, their experiments being directed chiefly toward determining the fate of the erythrocytes. Pearce (1918) in reporting the effects of experimental splenectomy in dogs, states that there are definite compensatory changes in the lymph nodes, in the form of an increased proliferation of endothelial phagocytes, and that the stellate cells of the liver sinusoids often show a similar compensatory increase in number. In both cases the cells are, apparently, formed in situ rather than transported to the organs. He says: ‘Such findings suggest the development of a compensatory function on the part of the lymph-nodes and possibly the liver,’ and suggests that, in times of stress ‘the stellate cells of the liver thus assume, in part at least, the function of destroying red blood-corpuscles by phagocytosis.’ Incidentally, he presents an excellent discussion of the history and subject of splenectomy. Motohashi (1922) reports a great increase in the hemophagic power of the hepatic endothelium and an increase in the number of endothelial elements, after some 45 days following splenectomy in rabbits. Nishikawa and Takagi (1922) have observed similar phenomena with white rats, the Kupffer cells taking up erythrocytes in large numbers in splenectomized animals, whereas controls never show similar propensities on the part of these cells. It may be that different substances cause different reactions on the part of the hepatic endothelium. Contributory Experiment.—A side experiment was performed with five rabbits, two splenectomized and three controls, into which uniform doses of pneumococci were injected intravenously. They all died of septicemia after a few days. The results

  3. Noncanonical Reactions of Flavoenzymes

    Directory of Open Access Journals (Sweden)

    Pablo Sobrado

    2012-11-01

    Full Text Available Enzymes containing flavin cofactors are predominantly involved in redox reactions in numerous cellular processes where the protein environment modulates the chemical reactivity of the flavin to either transfer one or two electrons. Some flavoenzymes catalyze reactions with no net redox change. In these reactions, the protein environment modulates the reactivity of the flavin to perform novel chemistries. Recent mechanistic and structural data supporting novel flavin functionalities in reactions catalyzed by chorismate synthase, type II isopentenyl diphosphate isomerase, UDP-galactopyranose mutase, and alkyl-dihydroxyacetonephosphate synthase are presented in this review. In these enzymes, the flavin plays either a direct role in acid/base reactions or as a nucleophile or electrophile. In addition, the flavin cofactor is proposed to function as a “molecular scaffold” in the formation of UDP-galactofuranose and alkyl-dihydroxyacetonephosphate by forming a covalent adduct with reaction intermediates.

  4. Fabrication, Characterization, and Optimization of CdS and CdSe Quantum Dot-Sensitized Solar Cells with Quantum Dots Prepared by Successive Ionic Layer Adsorption and Reaction

    Directory of Open Access Journals (Sweden)

    H. K. Jun

    2014-01-01

    Full Text Available CdS and CdSe quantum dot-sensitized solar cells (QDSSCs were used for the study of determining the optimum preparation parameters that could yield the best solar cell performance. The quantum dots (QDs were coated on the surface of mesoporous TiO2 layer deposited on FTO substrate using the successive ionic layer adsorption and reaction (SILAR method. In this method the QDs are allowed to grow on TiO2 by dipping the TiO2 electrode successively in two different solutions for predetermined times. This method allows the fabrication of QDs in a facile way. Three preparation parameters that control the QD fabrication were investigated: concentration of precursor solutions, number of dipping cycles (SILAR cycles, and dipping time in each solution. CdS based QDSSC showed optimum performance when the QDs were prepared from precursor solutions having the concentration of 0.10 M using 4 dipping cycles with the dipping time of 5 minutes in each solution. For CdSe QDSSC, the optimum performance was achieved with QDs prepared from 0.03 M precursor solutions using 7 dipping cycles with 30 s dipping time in each solution. The QDs deposited on TiO2 surface were characterized using UV-vis absorption spectroscopy, FESEM, and TEM imaging.

  5. Overcoming Short-Circuit in Lead-Free CH3NH3SnI3 Perovskite Solar Cells via Kinetically Controlled Gas-Solid Reaction Film Fabrication Process.

    Science.gov (United States)

    Yokoyama, Takamichi; Cao, Duyen H; Stoumpos, Constantinos C; Song, Tze-Bin; Sato, Yoshiharu; Aramaki, Shinji; Kanatzidis, Mercouri G

    2016-03-03

    The development of Sn-based perovskite solar cells has been challenging because devices often show short-circuit behavior due to poor morphologies and undesired electrical properties of the thin films. A low-temperature vapor-assisted solution process (LT-VASP) has been employed as a novel kinetically controlled gas-solid reaction film fabrication method to prepare lead-free CH3NH3SnI3 thin films. We show that the solid SnI2 substrate temperature is the key parameter in achieving perovskite films with high surface coverage and excellent uniformity. The resulting high-quality CH3NH3SnI3 films allow the successful fabrication of solar cells with drastically improved reproducibility, reaching an efficiency of 1.86%. Furthermore, our Kelvin probe studies show the VASP films have a doping level lower than that of films prepared from the conventional one-step method, effectively lowering the film conductivity. Above all, with (LT)-VASP, the short-circuit behavior often obtained from the conventional one-step-fabricated Sn-based perovskite devices has been overcome. This study facilitates the path to more successful Sn-perovskite photovoltaic research.

  6. Nuclear reaction studies

    International Nuclear Information System (INIS)

    Alexander, J.M.; Lacey, R.A.

    1994-01-01

    Research focused on the statistical and dynamical properties of ''hot'' nuclei formed in symmetric heavy-ion reactions. Theses included ''flow'' measurements and the mechanism for multifragment disassembly. Model calculations are being performed for the reactions C+C, Ne+Al, Ar+Sc, Kr+Nb, and Xe+La. It is planned to study 40 Ar reactions from 27 to 115 MeV/nucleon. 2 figs., 41 refs

  7. Knock-out reactions

    International Nuclear Information System (INIS)

    de Forest, T. Jr.

    1977-01-01

    It is pointed out that the primary motivation for performing high energy single nucleon knock-out reactions is based on the concept of quasi-elastic scattering. The validity of and corrections to the partial wave impulse approximation and kinematical invariance of knock-out reactions and tests of the reaction mechanism are treated. The effect of distortions on the momentum distribution in the effective momentum approximation for given parameters are plotted. 12 references

  8. Reaction kinetics of polybutylene terephthalate polycondensation reaction

    NARCIS (Netherlands)

    Darda, P. J.; Hogendoorn, J. A.; Versteeg, G. F.; Souren, F.

    2005-01-01

    The kinetics of the forward polycondensation reaction of polybutylene terephthalate (PBT) has been investigated using thermogravimetric analysis (TGA). PBT - prepolymer with an initial degree of polymerization of 5.5 was used as starting material. The PBT prepolymer was prepared from dimethyl

  9. Determination of the distribution and reaction of polysaccharides in wood cell walls by the isotope tracer technique, 6: Selective radio-labeling of mannan in ginkgo (Ginkgo biloba)

    International Nuclear Information System (INIS)

    Imai, T.; Terashima, N.; Yasuda, S.

    1997-01-01

    D-Mannose-[2-H-3] and GDP (guanosine diphosphate)-D-mannose-[mannose-1-H-3] were administered to the shoots of ginkgo (Ginkgo biloba L.) tolabel mannan selectively in the cell walls. To suppress the incorporation of radioactivity into the lignin and cellulose, the precursors were administered in the presence of the inhibitor of phenylalanine ammonia-lyase (PAL): namely, L-alpha-aminooxy-beta-phenylpropionic acid (AOPP) and the inhibitor of glucan synthesis: namely, 2-deoxy-D-glucose (2-DG) and 2.6-dichlorobenzonitrile (2.6-DCB). When D-mannose-[2-H-3] was administered in the absence of the inhibitors, great radioactivities were found in the mannose and glucose obtained by sulfuric acid hydrolysis of the newly-formed xylem, and also in the vanillin obtained by nitrobenzene oxidation. These results indicate that the radioactivity was incorporated not only into mannan but also into cellulose and lignin. When D-mannose-[2-H-3] was administered in the presence of both AOPP and 2-DG, the radioactivities of vanillin and glucose were decreased but that of mannose was not decreased. These results indicate that the incorporations of radioactivities into lignin and cellulose were suppressed by the inhibitors, but the incorporation into mannan was not interfered with. The treatment with 2,6-DCB lessened the incorporations of radioactivity into vanillin, xylose, mannose, and glucose of the newly formed xylem considerably which indicated that 2,6-DCB disturbed the metabolic activities of the plant fatally. Consequently, the selective radiolabeling of mannan in ginkgo was achieved by the administration of D-mannose-[2-H-3], in the presence of both AOPP and 2-DG, toa growing stem. In the case of GDP-D-mannose-[mannose-1-H-3], the radioactivity incorporated into the newly-formed xylem was very little, and the selectivity in labeling and the effects of the inhibitors were not clear

  10. Importance of the functional state of alveolar macrophages of the lungs for hygienic evaluation of protective reactions and cell damage due to atmospheric pollution

    Energy Technology Data Exchange (ETDEWEB)

    Tusl, M; Vyskocil, A; Duerrer, I; Aulika, B V; Litvinov, N N; Merkur' eva, R V

    1983-01-01

    Total number of cells, their viability and ability to adhesion were examined in surface alveolar macrophages isolated from rat livers after exposure to sulphur dioxide during 2, 4 and 6 weeks (0.05, 0.5, 1.0 and 5.0 mg/m3); to nitrogen oxide during 5, 8 and 15 hours, 28 and 56 days (19 mg/m3) and to carbon monoxide during 2, 28 and 56 days (0.01% or 10 MAC). In the experiment with exposure to sulphur dioxide, the activity of enzymes of varying localization in the macrophages - soluble in the cytoplasm (lactate dehydrogenase) and connected with subcellular structures - lysosomes (beta-galactosidase, beta-glucosidase and acid phosphatase) was tested by means of biochemical methods in parallel with cytological examinations. Low concentrations of various chemical contaminants of the atmospheric air (sulphur dioxide, nitrogen oxides, carbon monoxide) have an unfavourable biological effect on rats, manifest in the impairment of local immunity, i.e., decreased number of alveolar macrophages, disturbance of their viability and reduced ability of the macrophages to adhesion. At the same time, sulphur dioxide induces enzyme disorganization in lactate dehydrogenase and in a number of lysosomal enzymes of the macrophages. These results serve as a basis for the recommendation of cytobiochemical methods of elaborating methodological approaches to the regulation of environmental factors. Alveolar macrophages as a constituent part of the mononuclear phagocytic system ensuring local non-specific and specific resistance of the organism form one of the most important cellular mechanisms of protection of the organism against the harmful effect of environmental factors including chemical contaminants of the atmospheric air (1, 2).

  11. Thermonuclear reaction listing

    International Nuclear Information System (INIS)

    Fukai, Yuzo

    1993-01-01

    The following 10 elements, including T, are well known as nuclear fusion fuels: p, D, T, 3 He, 4 He, 6 Li, 7 Li, 9 Be, 10 B, 11 B, ( 12 C, 13 C), where 12 C and 13 C are considered only in the calculation of Q value. Accordingly the number of the thermonuclear reactions is 55, and 78, if including carbon elements. The reactions have some branches. For the branches having two and three reaction products, the reaction products, Q value and threshold energy are calculated by using a computer. We have investigated those of the branches having more than three products from the papers of Ajzenberg-Selove and so on. And also, by the same papers, we check whether the above mentioned branch has been observed or not. The results are as follows: (I) the number of reactions which have Q 0 branches only with γ ray production, and Q 0 and neutron production is 36(17), and (IV) that of reactions whose branch with Q > 0 does not produce neutrons is 9(3). The value in the parentheses shows the number of the case of the carbon elements. For 55 thermonuclear reactions induced by lighter nuclides than 11 B, the reaction products, the values of Q and threshold energy, and the papers with reaction cross section data are presented in the tables. (author)

  12. Sleeve reaction chamber system

    Science.gov (United States)

    Northrup, M Allen [Berkeley, CA; Beeman, Barton V [San Mateo, CA; Benett, William J [Livermore, CA; Hadley, Dean R [Manteca, CA; Landre, Phoebe [Livermore, CA; Lehew, Stacy L [Livermore, CA; Krulevitch, Peter A [Pleasanton, CA

    2009-08-25

    A chemical reaction chamber system that combines devices such as doped polysilicon for heating, bulk silicon for convective cooling, and thermoelectric (TE) coolers to augment the heating and cooling rates of the reaction chamber or chambers. In addition the system includes non-silicon-based reaction chambers such as any high thermal conductivity material used in combination with a thermoelectric cooling mechanism (i.e., Peltier device). The heat contained in the thermally conductive part of the system can be used/reused to heat the device, thereby conserving energy and expediting the heating/cooling rates. The system combines a micromachined silicon reaction chamber, for example, with an additional module/device for augmented heating/cooling using the Peltier effect. This additional module is particularly useful in extreme environments (very hot or extremely cold) where augmented heating/cooling would be useful to speed up the thermal cycling rates. The chemical reaction chamber system has various applications for synthesis or processing of organic, inorganic, or biochemical reactions, including the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction.

  13. Tattoo reaction: Case series

    Directory of Open Access Journals (Sweden)

    Muneer Mohamed

    2018-04-01

    Full Text Available Tattoo is going to be a very common practice especially among young people and we are witnessing a gradual increase of numerous potential complications to tattoo placement which are often seen by physicians, but generally unknown to the public. The most common skin reactions to tattoo include a transient acute inflammatory reaction due to trauma of the skin with needles and medical complications such as superficial and deep local infections, systemic infections, allergic contact dermatitis, photodermatitis, granulomatous and lichenoid reactions, and skin diseases localized on tattooed area (eczema, psoriasis, lichen, and morphea. In this series we present three cases of tattoo reaction.

  14. Ruthenium nanocatalysis on redox reactions.

    Science.gov (United States)

    Veerakumar, Pitchaimani; Ramdass, Arumugam; Rajagopal, Seenivasan

    2013-07-01

    Nanoparticles have generated intense interest over the past 20 years due to their high potential applications in different areas such as catalysis, sensors, nanoscale electronics, fuel and solar cells and optoelectronics. As the large fractions of metal atoms are exposed to the surface, the use of metal nanoparticles as nanocatalysts allows mild reaction conditions and high catalytic efficiency in a large number of chemical transformations. They have emerged as sustainable heterogeneous catalysts and catalyst supports alternative to conventional materials. This review focuses on the synthesis, characterization and catalytic role of ruthenium nanoparticles (RuNPs) on the redox reactions of heteroatom containing organic compounds with the green reagent H2O2, a field that has attracted immense interest among the chemical, materials and industrial communities. We intend to present a broad overview of Ru nanocatalysts for redox reactions with an emphasis on their performance, stability and reusability. The growth in the chemistry of organic sulfoxides and N-oxides during last decade was due to their importance as synthetic intermediates for the production of a wide range of chemically and biologically active molecules. Thus design of efficient methods for the synthesis of sulfoxides and N-oxides becomes important. This review concentrates on the catalysis of RuNPs on the H2O2 oxidation of organic sulfides to sulfoxides and amines to N-oxides. The deoxygenation reactions of sulfoxides to sulfides and reduction of nitro compounds to amines are fundamental reactions in both chemistry and biology. Here, we also highlight the catalysis of metal nanoparticles on the deoxygenation of sulfoxides and sulfones and reduction of nitro compounds with particular emphasis on the mechanistic aspects.

  15. Proactive management strategies for potential gastrointestinal adverse reactions with ceritinib in patients with advanced ALK-positive non-small-cell lung cancer

    International Nuclear Information System (INIS)

    Schaefer, Eric S; Baik, Christina

    2016-01-01

    Anaplastic lymphoma kinase (ALK) gene fusions occur in 3%–7% of non-small-cell lung cancer (NSCLC) cases. Ceritinib, a once-daily, oral ALK inhibitor, has activity against crizotinib-resistant and crizotinib-naïve NSCLC, including brain metastases. Ceritinib (Zykadia™) was granted accelerated approval by the US Food and Drug Administration in 2014 for treating crizotinib-resistant ALK-positive NSCLC. Adverse events (AEs), particularly gastrointestinal (GI) AEs, are commonly experienced at the recommended dose of 750 mg/d and ∼38% of patients require dose interruption or reduction for GI AEs. This case study details our experience with the use of proactive GI AE management regimens in patients treated with ceritinib (750 mg/d) across two study sites. Proactive Regimens A and B were implemented in patients with metastatic ALK-positive NSCLC treated with ceritinib to manage drug-related GI AEs. Regimen A comprised ondansetron and diphenoxylate/atropine or loperamide, taken 30 minutes prior to ceritinib dose. Regimen B included dicyclomine (taken with the first ceritinib dose), ondansetron (taken 30 minutes prior to ceritinib dose for the first seven doses), and loperamide (taken as needed with the onset of diarrhea). The proactive medications were tapered off depending on patient tolerability to ceritinib. Nine patient cases are presented. Starting Regimens A or B before the first dose of ceritinib, or as soon as GI symptoms were encountered, prevented the need for dose reduction due to GI toxicity in eight of the nine patients. Using these regimens, 78% of patients were able to remain on 750 mg/d fasting. Two patients received 23 months and 16 months of therapy and remain on ceritinib 750 mg/d and 600 mg/d, respectively. Although not currently recommended or implemented in clinical studies, based on the patients evaluated here, upfront or proactive treatment plans that address AEs early on can allow the majority of patients to remain on the approved 750 mg

  16. Nonlinear mixed effects dose response modeling in high throughput drug screens: application to melanoma cell line analysis.

    Science.gov (United States)

    Ding, Kuan-Fu; Petricoin, Emanuel F; Finlay, Darren; Yin, Hongwei; Hendricks, William P D; Sereduk, Chris; Kiefer, Jeffrey; Sekulic, Aleksandar; LoRusso, Patricia M; Vuori, Kristiina; Trent, Jeffrey M; Schork, Nicholas J

    2018-01-12

    Cancer cell lines are often used in high throughput drug screens (HTS) to explore the relationship between cell line characteristics and responsiveness to different therapies. Many current analysis methods infer relationships by focusing on one aspect of cell line drug-specific dose-response curves (DRCs), the concentration causing 50% inhibition of a phenotypic endpoint (IC 50 ). Such methods may overlook DRC features and do not simultaneously leverage information about drug response patterns across cell lines, potentially increasing false positive and negative rates in drug response associations. We consider the application of two methods, each rooted in nonlinear mixed effects (NLME) models, that test the relationship relationships between estimated cell line DRCs and factors that might mitigate response. Both methods leverage estimation and testing techniques that consider the simultaneous analysis of different cell lines to draw inferences about any one cell line. One of the methods is designed to provide an omnibus test of the differences between cell line DRCs that is not focused on any one aspect of the DRC (such as the IC 50 value). We simulated different settings and compared the different methods on the simulated data. We also compared the proposed methods against traditional IC 50 -based methods using 40 melanoma cell lines whose transcriptomes, proteomes, and, importantly, BRAF and related mutation profiles were available. Ultimately, we find that the NLME-based methods are more robust, powerful and, for the omnibus test, more flexible, than traditional methods. Their application to the melanoma cell lines reveals insights into factors that may be clinically useful.

  17. Hydrogen evolution reaction catalyst

    Science.gov (United States)

    Subbaraman, Ram; Stamenkovic, Vojislav; Markovic, Nenad; Tripkovic, Dusan

    2016-02-09

    Systems and methods for a hydrogen evolution reaction catalyst are provided. Electrode material includes a plurality of clusters. The electrode exhibits bifunctionality with respect to the hydrogen evolution reaction. The electrode with clusters exhibits improved performance with respect to the intrinsic material of the electrode absent the clusters.

  18. Precompound Reactions: Basic Concepts

    International Nuclear Information System (INIS)

    Weidenmueller, H. A.

    2008-01-01

    Because of the non-zero nuclear equilibration time, the compound-nucleus scattering model fails when the incident energy exceeds 10 or 20 MeV, and precompound reactions become important. Basic ideas used in the quantum-statistical approaches to these reactions are described

  19. Nuclear Reaction Data Centers

    International Nuclear Information System (INIS)

    McLane, V.; Nordborg, C.; Lemmel, H.D.; Manokhin, V.N.

    1988-01-01

    The cooperating Nuclear Reaction Data Centers are involved in the compilation and exchange of nuclear reaction data for incident neutrons, charged particles and photons. Individual centers may also have services in other areas, e.g., evaluated data, nuclear structure and decay data, reactor physics, nuclear safety; some of this information may also be exchanged between interested centers. 20 refs., 1 tab

  20. Fluorogenic organocatalytic reactions

    NARCIS (Netherlands)

    Raeisolsadati Oskouei, M.

    2017-01-01

    In this thesis, we introduce fluorescence spectroscopy as a new tool to gain insight into the interactions between the substrates and catalyst during organocatalytic reactions. The ultimate goal is to resolve the kinetics of the binding and reaction steps and obtain detailed understanding of the

  1. Applications of Reaction Rate

    Science.gov (United States)

    Cunningham, Kevin

    2007-01-01

    This article presents an assignment in which students are to research and report on a chemical reaction whose increased or decreased rate is of practical importance. Specifically, students are asked to represent the reaction they have chosen with an acceptable chemical equation, identify a factor that influences its rate and explain how and why it…

  2. Chemical burn or reaction

    Science.gov (United States)

    Chemicals that touch skin can lead to a reaction on the skin, throughout the body, or both. ... leave the person alone and watch carefully for reactions affecting the entire body. Note: If a chemical gets into the eyes, the eyes should be ...

  3. Degradations and Rearrangement Reactions

    Science.gov (United States)

    Zhang, Jianbo

    This section deals with recent reports concerning degradation and rearrangement reactions of free sugars as well as some glycosides. The transformations are classified in chemical and enzymatic ways. In addition, the Maillard reaction will be discussed as an example of degradation and rearrangement transformation and its application in current research in the fields of chemistry and biology.

  4. Reação transfusional hiper-hemolítica em pacientes portadores de anemia falciforme: relato de dois casos Hyper-hemolytic transfusional reaction in sickle cell patients: two case reports

    Directory of Open Access Journals (Sweden)

    Cláudia C.S. Naufel

    2002-12-01

    increased frequency of transfusions to which these patients are submitted, knowledge of the main risks and an adequate diagnosis of the complications caused by transfusional therapy are of fundamental importance. An atypical form of transfusional reaction, denominated hyperhemolytic transfusional reaction was recently described in sickle cell anemia patients after the transfusion of apparently compatible hemacias. In this case, previous conditions can exacerbate the hemolytic condition and put the life of the patient at risk. The pathophysiological conditions of this disease are not yet understood well and the treatment consists of suspending transfusions, corticoid therapy and / or administration of immunoglobulin. The aim of this work is o present two case reports of hyperhemolytic transfusional reaction in sickle cell anemia patients.

  5. Microdosimetric concepts for indirect radiation reactions

    International Nuclear Information System (INIS)

    Pohlit, W.

    1976-01-01

    It is the aim of microdosimetric models to get information about the influence of microscopic energy deposition by radiation on radiation reactions. Two parameters are always of interest: the energy necessary to produce a certain reaction and the volume in which this energy has to be desposited. In the simple case of an aqueous solution with point targets a complete description of radiation reactions in targets with various concentrations can be given. This model takes into consideration the distinct energy deposition on the particle track, diffusion of radicals and a mean energy necessary for a certain reaction at the target. Typical dose effect curves are obtained which allow the determination of all these quantities from experiments. The model has been tested with the oxydation of iron atoms in aqueous solutions and has been applied for more complex targets such as different alcohols and amino acids. The oxygen consumption in these reactions is used as an easy method for continuous measurement of these indirect reactions. It is the aim of such experiments to get enough quantitative microscopic data on indirect radiation reactions that these reactions can also be followed in living cells

  6. Ultra-trace determination of Strontium-90 in environmental soil samples from Qatar by collision/reaction cell-inductively coupled plasma mass spectrometry (CRC-ICP-MS/MS)

    Energy Technology Data Exchange (ETDEWEB)

    Al-Meer, S. H.; Amr, M. A. [Central Laboratories Unit, Qatar University, Doha (Qatar); Helal, A.I. [Atomic Energy Authority, Cairo (Egypt); Al-Kinani, A.T. [Minstery of Environment, Doha (Qatar)

    2013-07-01

    Because of the very low level of {sup 90}Sr in the environmental soil samples and its determination by beta counting may take several weeks, we developed a procedure for ultra-trace determination of {sup 90}Sr using collision reaction cell-inductively coupled plasma tandem mass spectrometry (CRC-ICP-MS/MS, Agilent 8800). Soil samples were dried at 105 deg. C and then heated in a furnace at 550 deg. C to remove any organics present. 500 g of each soil samples were aliquoted into 2000 ml glass beakers. Each Soils samples were soaked in 2 ppm Sr solution carrier to allow determination of chemical yield. The solid to liquid ratio was 1:1. Finally the soil samples were dried at 105 deg. C. Five hundred milliliters concentrated nitric acid and 250 ml hydrochloric acid volumes were added on 500 g soil samples. The samples were digested on hot plate at 80 deg. C to prevent spraying with continuous manual mixing. The leachate solution was separated. The solids were rinsed with 500 ml deionized water, warmed on a hot plate and the leachate plus previous leachate were filtered and the total volume was reduced to 500 ml by evaporation. Final leachate volume was transferred to a centrifuge tubes. The centrifuge tubes were centrifuged at 3,500 rpm for 10 min. The leachate was transferred to a 1 L beaker and heated on a hot plate to evaporate the leachate to dryness. The reside was re-dissolved in 100 ml of 2% HNO{sub 3} and reduced by evaporation to 10 mL. The solution was measured directly by CRC-ICP-MS/MS by setting the first quadruple analyzer to m/z 90 and introducing oxygen gas into the reaction cell for elimination isobar interference from zirconium-90. The method was validated by measurements of standard reference materials and applied on environmental soil samples. The overall time requirement for the measurement of strontium-90 by CRC-ICP-MS/MS is 2 days, significantly shorter than any radioanalytical protocol currently available. (authors)

  7. Increased Expression of T Cell Immunoglobulin and Mucin Domain 3 on CD14+ Monocytes Is Associated with Systemic Inflammatory Reaction and Brain Injury in Patients with Spontaneous Intracerebral Hemorrhage.

    Science.gov (United States)

    Xu, ChangJun; Ge, HaiTao; Wang, Tao; Qin, JianBing; Liu, De; Liu, YuGuang

    2018-05-01

    To study the expression of T cell immunoglobulin and mucin domain 3 (Tim-3) on peripheral blood immunocytes, and the relationship between Tim-3 and the systemic inflammatory response or brain injury in patients with intracerebral hemorrhage (ICH). According to the volume of hematoma at 12 hours after onset of ICH, 60 newly diagnosed patients with ICH were divided into the small (volume of hematoma <30 mL, 30 cases) and large (volume of hematoma ≥30 mL, 30 cases) ICH groups. The expression of Tim-3 on peripheral blood immunocytes was analyzed by flow cytometry. Real-time reverse transcriptase polymerase chain reaction was used to detect Tim-3 mRNA on peripheral blood mononuclear cells (PBMCs). Meanwhile, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and S-100B protein were measured by enzyme-linked immunosorbent assay. Glasgow outcome scale (GOS) score at Day 30 was used to estimate prognosis of patients. The leukocyte count, neutrophil count, monocyte count, TNF-α, IL-1β, and S-100B protein increased remarkably after ICH. However, all of them in the large ICH group increased more obviously, and there were significant differences when compared with those in the small ICH group (P < .01). The expression of Tim-3 mRNA on PBMCs in the large ICH group increased remarkably, peaked at Day 3, and was positively associated with the concentrations of TNF-α, IL-1β, and S-100B protein (P < .01). Tim-3 was predominantly expressed itself on CD14 + monocytes. There was a negative correlation between GOS score and Tim-3 mRNA, TNF-α, IL-1β, or S-100B protein. The expression of Tim-3 on CD14 + monocytes involves in systemic inflammatory reaction after ICH and may be a novel treatment target. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  8. Heavy ion transfer reactions

    International Nuclear Information System (INIS)

    Weisser, D.C.

    1977-06-01

    To complement discussions on the role of γ rays in heavy ion induced reactions, the author discusses the role played by particle detection. Transfer reactions are part of this subject and are among those in which one infers the properties of the residual nucleus in a reaction by observing the emerging light nucleus. Inelastic scattering ought not be excluded from this subject, although no particles are transferred, because of the role it plays in multistep reactions and in fixing O.M. parameters describing the entrance channel of the reaction. Heavy ion transfer reaction studies have been under study for some years and yet this research is still in its infancy. The experimental techniques are difficult and the demands on theory rigorous. One of the main products of heavy ion research has been the thrust to re-examine the assumptions of reaction theory and now include many effects neglected for light ion analysis. This research has spurred the addition of multistep processes to simple direct processes and coupled channel calculations. (J.R.)

  9. Enhancing chemical reactions

    Science.gov (United States)

    Morrey, John R.

    1978-01-01

    Methods of enhancing selected chemical reactions. The population of a selected high vibrational energy state of a reactant molecule is increased substantially above its population at thermal equilibrium by directing onto the molecule a beam of radiant energy from a laser having a combination of frequency and intensity selected to pump the selected energy state, and the reaction is carried out with the temperature, pressure, and concentrations of reactants maintained at a combination of values selected to optimize the reaction in preference to thermal degradation by transforming the absorbed energy into translational motion. The reaction temperature is selected to optimize the reaction. Typically a laser and a frequency doubler emit radiant energy at frequencies of .nu. and 2.nu. into an optical dye within an optical cavity capable of being tuned to a wanted frequency .delta. or a parametric oscillator comprising a non-centrosymmetric crystal having two indices of refraction, to emit radiant energy at the frequencies of .nu., 2.nu., and .delta. (and, with a parametric oscillator, also at 2.nu.-.delta.). Each unwanted frequency is filtered out, and each desired frequency is focused to the desired radiation flux within a reaction chamber and is reflected repeatedly through the chamber while reactants are fed into the chamber and reaction products are removed therefrom.

  10. The Reaction Wheel Pendulum

    CERN Document Server

    Block, Daniel J; Spong, Mark W

    2007-01-01

    This monograph describes the Reaction Wheel Pendulum, the newest inverted-pendulum-like device for control education and research. We discuss the history and background of the reaction wheel pendulum and other similar experimental devices. We develop mathematical models of the reaction wheel pendulum in depth, including linear and nonlinear models, and models of the sensors and actuators that are used for feedback control. We treat various aspects of the control problem, from linear control of themotor, to stabilization of the pendulum about an equilibrium configuration using linear control, t

  11. Electron transfer reactions

    CERN Document Server

    Cannon, R D

    2013-01-01

    Electron Transfer Reactions deals with the mechanisms of electron transfer reactions between metal ions in solution, as well as the electron exchange between atoms or molecules in either the gaseous or solid state. The book is divided into three parts. Part 1 covers the electron transfer between atoms and molecules in the gas state. Part 2 tackles the reaction paths of oxidation states and binuclear intermediates, as well as the mechanisms of electron transfer. Part 3 discusses the theories and models of the electron transfer process; theories and experiments involving bridged electron transfe

  12. Firefighter Nozzle Reaction

    DEFF Research Database (Denmark)

    Chin, Selena K.; Sunderland, Peter B.; Jomaas, Grunde

    2017-01-01

    to anchor forces, the hose becomes straight. The nozzle reaction is found to equal the jet momentum flow rate, and it does not change when an elbow connects the hose to the nozzle. A forward force must be exerted by a firefighter or another anchor that matches the forward force that the jet would exert...... on a perpendicular wall. Three reaction expressions are derived, allowing it to be determined in terms of hose diameter, jet diameter, flow rate, and static pressure upstream of the nozzle. The nozzle reaction predictions used by the fire service are 56% to 90% of those obtained here for typical firefighting hand...

  13. Fetal RHD Genotyping Using Real-Time Polymerase Chain Reaction Analysis of Cell-Free Fetal DNA in Pregnancy of RhD Negative Women in South of Iran

    Directory of Open Access Journals (Sweden)

    Leili Moezzi

    2016-05-01

    Full Text Available Background: Maternal-fetal RhD antigen incompatibility causes approximately 50% of clinically significant alloimmunization cases. The routine use of prophylactic anti-D immunoglobulin has dramatically reduced hemolytic disease of the fetus and newborn. Recently, fetal RHD genotyping in RhD negative pregnant women has been suggested for appropriate use of anti-D immunoglobulin antenatal prophylaxis and decrease unnecessary prenatal interventions. Materials and Methods: In this prospective cohort study, in order to develop a reliable and non-invasive method for fetal RHD genotyping, cell free fetal DNA (cffDNA was extracted from maternal plasma. Real-time quantitative polymerase chain reaction (qPCR for detection of RHD exons 7, 5, 10 and intron 4 was performed and the results were compared to the serological results of cord blood cells as the gold standard method. SRY gene and hypermethylated Ras-association domain family member 1 (RASSF1A gene were used to confirm the presence of fetal DNA in male and female fetuses, respectively. Results: Out of 48 fetuses between 8 and 32 weeks (wks of gestational age (GA, we correctly diagnosed 45 cases (93.75% of RHD positive fetuses and 2 cases (4.16% of the RHD negative one. Exon 7 was amplified in one sample, while three other RHD gene sequences were not detected; the sample was classified as inconclusive, and the RhD serology result after birth showed that the fetus was RhD-negative. Conclusion: Our results showed high accuracy of the qPCR method using cffDNA for fetal RHD genotyping and implicate on the efficiency of this technique to predict the competence of anti-D immunoglobulin administration.

  14. Processing of CuInSe{sub 2}-based solar cells: Characterization of deposition processes in terms of chemical reaction analyses. Phase 2 Annual Report, 6 May 1996--5 May 1997

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, T.

    1999-10-20

    This report describes research performed by the University of Florida during Phase 2 of this subcontract. First, to study CIGS, researchers adapted a contactless, nondestructive technique previously developed for measuring photogenerated excess carrier lifetimes in SOI wafers. This dual-beam optical modulation (DBOM) technique was used to investigate the differences between three alternative methods of depositing CdS (conventional chemical-bath deposition [CBD], metal-organic chemical vapor deposition [MOCVD], and sputtering). Second, a critical assessment of the Cu-In-Se thermochemical and phase diagram data using standard CALPHAD procedures is being performed. The outcome of this research will produce useful information on equilibrium vapor compositions (required annealing ambients, Sex fluxes from effusion cells), phase diagrams (conditions for melt-assisted growth), chemical potentials (driving forces for diffusion and chemical reactions), and consistent solution models (extents of solid solutions and extending phase diagrams). Third, an integrated facility to fabricate CIS PV devices was established that includes migration-enhanced epitaxy (MEE) for deposition of CIS, a rapid thermal processing furnace for absorber film formation, sputtering of ZnO, CBD or MOCVD of CdS, metallization, and pattern definition.

  15. The value of molecular expression of KIT and KIT ligand analysed using real-time polymerase chain reaction and immunohistochemistry as a prognostic indicator for canine cutaneous mast cell tumours.

    Science.gov (United States)

    Costa Casagrande, T A; de Oliveira Barros, L M; Fukumasu, H; Cogliati, B; Chaible, L M; Dagli, M L Z; Matera, J M

    2015-03-01

    This study investigated the correlation between KIT gene expression determined by immunohistochemistry and real-time polymerase chain reaction (RT-PCR) and the rate of tumour recurrence and tumour-related deaths in dogs affected with mast cell tumour (MCT). Kaplan-Meier curves were constructed to compare tumour recurrence and tumour-related death between patients. The log-rank test was used to check for significant differences between curves. KIT-I, KIT-II and KIT-III staining patterns were observed in 9 (11.11%), 50 (61.73%) and 22 (27.16%) tumours, respectively. Tumour recurrence rates and tumour-related deaths were not associated with KIT staining patterns (P = 0278, P > 0.05), KIT (P = 0.289, P > 0.05) or KIT ligand (P = 0.106, P > 0.05) gene expression. Despite the lack of association between KIT staining pattern and patient survival time, the results suggest a correlation between aberrant KIT localization and increased proliferative activity of MCTs. RT-PCR seems to be a sensible method for quantitative detection of KIT gene expression in canine MCT, although expressions levels are not correlated with prognosis. © 2013 Blackwell Publishing Ltd.

  16. A novel IrNi@PdIr/C core-shell electrocatalyst with enhanced activity and durability for the hydrogen oxidation reaction in alkaline anion exchange membrane fuel cells.

    Science.gov (United States)

    Qin, Bowen; Yu, Hongmei; Jia, Jia; Jun, Chi; Gao, Xueqiang; Yao, Dewei; Sun, Xinye; Song, Wei; Yi, Baolian; Shao, Zhigang

    2018-03-08

    Herein, a novel non-platinum core-shell catalyst, namely, IrNi@PdIr/C was prepared via a galvanic replacement reaction; it exhibits enhanced hydrogen oxidation activity and excellent stability under alkaline conditions. Electrochemical experiments demonstrated that the mass and specific activities at 50 mV of IrNi@PdIr/C are 2.1 and 2.2 times that of commercial Pt/C in 0.1 M KOH at 298 K, respectively. Moreover, accelerated degradation tests have shown that the electrochemically active surface area (ECSA) of IrNi@PdIr/C reduces by only 5.1%, which is almost 4 times less than that of commercial Pt/C and the mass activity at 50 mV of IrNi@PdIr/C after 2000 potential cycles is still 1.8 times higher than that of aged Pt/C. XRD and XPS analysis suggest that the enhanced HOR activity is attributed to the weakening of the hydrogen binding to the PdIr overlayers induced by the IrNi core. The better stability to potential cycling can be associated with the PdIr shell, which inhibits oxide formation. These results suggest that IrNi@PdIr/C is a promising non-platinum anode catalyst for alkaline anion exchange membrane fuel cells.

  17. Nucleon induced reactions

    International Nuclear Information System (INIS)

    Gmuca, S.; Antalik, R.; Kristiak, J.

    1988-01-01

    The collection contains full texts of 37 contributions; all fall within the INIS Subject Scope. The topics treated include some unsolved problems of nuclear reactions and relevant problems of nuclear structure at low and intermediate energies. (Z.S.)

  18. Reactor for exothermic reactions

    Science.gov (United States)

    Smith, L.A. Jr.; Hearn, D.; Jones, E.M. Jr.

    1993-03-02

    A liquid phase process is described for oligomerization of C[sub 4] and C[sub 5] isoolefins or the etherification thereof with C[sub 1] to C[sub 6] alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300 F. Wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

  19. Statistical nuclear reactions

    International Nuclear Information System (INIS)

    Hilaire, S.

    2001-01-01

    A review of the statistical model of nuclear reactions is presented. The main relations are described, together with the ingredients necessary to perform practical calculations. In addition, a substantial overview of the width fluctuation correction factor is given. (author)

  20. Photon induced reactions

    International Nuclear Information System (INIS)

    Mecking, B.A.

    1982-04-01

    Various aspects of medium energy nuclear reactions induced by real photons are reviewed. Special emphasis is put on high accuracy experiments that will become possible with the next generation of electron accelerators. (orig.)

  1. Transfusion reaction - hemolytic

    Science.gov (United States)

    ... Names Blood transfusion reaction Images Surface proteins causing rejection References Choate JD, Maitta RW, Tormey CA, Wu ... PA: Elsevier Saunders; 2016:chap 177. Hall JE. Blood types; transfusion; tissue and organ transplantation. In: Hall JE, ...

  2. Sequential charged particle reaction

    International Nuclear Information System (INIS)

    Hori, Jun-ichi; Ochiai, Kentaro; Sato, Satoshi; Yamauchi, Michinori; Nishitani, Takeo

    2004-01-01

    The effective cross sections for producing the sequential reaction products in F82H, pure vanadium and LiF with respect to the 14.9-MeV neutron were obtained and compared with the estimation ones. Since the sequential reactions depend on the secondary charged particles behavior, the effective cross sections are corresponding to the target nuclei and the material composition. The effective cross sections were also estimated by using the EAF-libraries and compared with the experimental ones. There were large discrepancies between estimated and experimental values. Additionally, we showed the contribution of the sequential reaction on the induced activity and dose rate in the boundary region with water. From the present study, it has been clarified that the sequential reactions are of great importance to evaluate the dose rates around the surface of cooling pipe and the activated corrosion products. (author)

  3. Reaction Qualifications Revisited

    DEFF Research Database (Denmark)

    Lippert-Rasmussen, Kasper

    2009-01-01

    to a person's effectiveness by causing a favourable reaction in customers, co-workers etc. (for short: recipients) - are involved, this assumption is false. Building on work by Wertheimer, Mason, and Miller, this paper proposes an account of the reaction qualifications that count, from the point of view...... preferences, recipients should not respond to the applicant actually hired on the basis of their (the recipients') racial preferences. My account decomposes the meritocratic ideal into four separate norms, one of which applies to recipients rather than to selectors. Finally, it defends the view that reaction...... qualifications based on antimeritocratic reactions, while not unproblematic, are not entirely irrelevant from the point of view of merit. Notably, selectors need not discount them when no one - including the targets of the objectionable preferences - is unfairly disadvantaged. Because not all problematic...

  4. Cutaneous adverse drug reactions

    African Journals Online (AJOL)

    CADRs).1 ... patient's management is thought to be responsible for the reaction. Some clinical ... In SJS/TEN hypotension, diarrhoea, hypothermia and confusion suggest ... and a pain management team, centred around a good core of experienced ...

  5. Reaction Qualifications Revisited

    DEFF Research Database (Denmark)

    Lippert-Rasmussen, Kasper

    2009-01-01

      When, in a competitive sphere, people are selected on the basis of qualifications only, their chances of acquiring positions of advantage may seem to depend entirely upon their abilities, not discriminatory bias. However, if reaction qualifications - i.e. characteristics which contribute...... to a person's effectiveness by causing a favourable reaction in customers, co-workers etc. (for short: recipients) - are involved, this assumption is false. Building on work by Wertheimer, Mason, and Miller, this paper proposes an account of the reaction qualifications that count, from the point of view...... of merit. Specifically, it preserves symmetry between negative evaluations of antimeritocratic bases of selection and negative evaluations of qualifications rooted in comparable antimeritocratic reactions. So if employers should not select among applicants on the basis of their (the employers') racial...

  6. Firefighter Nozzle Reaction

    DEFF Research Database (Denmark)

    Chin, Selena K.; Sunderland, Peter B.; Jomaas, Grunde

    2017-01-01

    Nozzle reaction and hose tension are analyzed using conservation of fluid momentum and assuming steady, inviscid flow and a flexible hose in frictionless contact with the ground. An expression that is independent of the bend angle is derived for the hose tension. If this tension is exceeded owing...... to anchor forces, the hose becomes straight. The nozzle reaction is found to equal the jet momentum flow rate, and it does not change when an elbow connects the hose to the nozzle. A forward force must be exerted by a firefighter or another anchor that matches the forward force that the jet would exert...... on a perpendicular wall. Three reaction expressions are derived, allowing it to be determined in terms of hose diameter, jet diameter, flow rate, and static pressure upstream of the nozzle. The nozzle reaction predictions used by the fire service are 56% to 90% of those obtained here for typical firefighting hand...

  7. Oxygen evolution reaction catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Haber, Joel A.; Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Jones, Ryan J.; Guevarra, Dan W.; Shinde, Aniketa A.

    2016-09-06

    An Oxygen Evolution Reaction (OER) catalyst includes a metal oxide that includes oxygen, cerium, and one or more second metals. In some instances, the cerium is 10 to 80 molar % of the metals in the metal oxide and/or the catalyst includes two or more second metals. The OER catalyst can be included in or on an electrode. The electrode can be arranged in an oxygen evolution system such that the Oxygen Evolution Reaction occurs at the electrode.

  8. Spallation reactions: calculations

    International Nuclear Information System (INIS)

    Bertini, H.W.

    1975-01-01

    Current methods for calculating spallation reactions over various energy ranges are described and evaluated. Recent semiempirical fits to existing data will probably yield the most accurate predictions for these reactions in general. However, if the products in question have binding energies appreciably different from their isotropic neighbors and if the cross section is approximately 30 mb or larger, then the intranuclear-cascade-evaporation approach is probably better suited. (6 tables, 12 figures, 34 references) (U.S.)

  9. Electrochemical Promotion of Catalytic Reactions Using

    DEFF Research Database (Denmark)

    Petrushina, Irina; Bjerrum, Niels; Cleemann, Lars Nilausen

    2007-01-01

    This paper presents the results of a study on electrochemical promotion (EP) of catalytic reactions using Pt/C/polybenzimidazole(H3PO4)/Pt/C fuel cell performed by the Energy and Materials Science Group (Technical University of Denmark) during the last 6 years[1-4]. The development of our...... understanding of the nature of the electrochemical promotion is also presented....

  10. Degradation reactions in SONY-type Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Roth, E.P.; Nagasubramanian, G.

    2000-07-01

    Thermal instabilities were identified in SONY-type lithium-ion cells and correlated with interactions of cell constituents and reaction products. Three temperature regions of interaction were identified and associated with the state of charge (degree of Li intercalation) of the cell. Anodes were shown to undergo exothermic reactions as low as 100 C involving the solid electrolyte interface (SEI) layer and the LiPF{sub 6} salt in the electrolyte (EC:PC:DEC/LiPF{sub 6}). These reactions could account for the thermal runaway observed in these cells beginning at 100 C. Exothermic reactions were also observed in the 200 C--300 C region between the intercalated lithium anodes, the LiPF{sub 6} salt, and the PVDF. These reactions were followed by a high-temperature reaction region, 300 C--400 C, also involving the PVDF binder and the intercalated lithium anodes. The solvent was not directly involved in these reactions but served as a moderator and transport medium. Cathode exothermic reactions with the PVDF binder were observed above 200 C and increased with the state of charge (decreasing Li content). This offers an explanation for the observed lower thermal runaway temperatures for charged cells.

  11. Cholangiocarcinoma with respect to IgG4 Reaction

    Directory of Open Access Journals (Sweden)

    Kenichi Harada

    2014-01-01

    Full Text Available IgG4 reactions marked by infiltration of IgG4-positive plasma cells in affected organs occur in cancer patients and in patients with IgG4-related diseases. Extrahepatic cholangiocarcinomas including gall bladder cancer are often accompanied by significant IgG4 reactions; t