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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. 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.

  5. 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).

  6. 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.

  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. 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.

  9. 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...

  10. 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...

  11. 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

  12. 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

  13. 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 ...

  14. 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.

  15. 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.)

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. 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

  9. 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.

  10. 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

  11. 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 ...

  12. 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

  13. 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

  14. 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.

  15. Quantification of pharmaceutical peptides in human plasma by LC-ICP-MS sulfur detection

    DEFF Research Database (Denmark)

    Møller, Laura Hyrup; Macherius, André; Hansen, Thomas Hesselhøj

    2016-01-01

    A method for quantification of a pharmaceutical peptide in human plasma was developed using gradient elution LC-ICP-MS. A membrane desolvation (MD) system was applied to remove organic solvents from the eluent prior to the detection as SO+ in the dynamic reaction cell (DRC) of the ICP-DRC-MS inst......A method for quantification of a pharmaceutical peptide in human plasma was developed using gradient elution LC-ICP-MS. A membrane desolvation (MD) system was applied to remove organic solvents from the eluent prior to the detection as SO+ in the dynamic reaction cell (DRC) of the ICP......-DRC-MS instrument and subsequent quantification by post-column isotope dilution (IDA). Plasma proteins were precipitated prior to analysis. Analytical figures of merit including linearity, precision, LOD, LOQ and accuracy were considered satisfactory for analysis of plasma samples. The selectivity of the developed...... method was demonstrated for five pharmaceutically relevant peptides: desmopressin, penetratin, substance P, PTH (1-34) and insulin. Preliminary experiments on an ICP-MS/MS system using oxygen to reduce the effect of organic solvents were also performed to compare sensitivity. The results of the study...

  16. 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

  17. 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

  18. 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.

  19. 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...

  20. 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

  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. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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

  10. 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...

  11. 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

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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

  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. 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.

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  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. 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.

  11. 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...

  12. 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

  13. 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.

  14. 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

  15. 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 ...

  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. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.)

  6. 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.

  7. 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

  8. 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

  9. 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

  10. Ultrasonic slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry for the determination of Cr, Fe, Cu, Zn and Se in cereals

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Shih-Yi [Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan (China); Jiang, Shiuh-Jen, E-mail: sjjiang@faculty.nsysu.edu.tw [Department of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan (China); Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan (China); Sahayam, A.C. [National Centre for Compositional Characterisation of Materials (CCCM), Hyderabad (India)

    2014-11-01

    Ultrasonic slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry (USS-ETV-ICP-MS) has been applied to determine Cr, Fe, Cu, Zn and Se in several cereal samples. Thioacetamide was used as the modifier to enhance the ion signals. The background ions at the masses of interest were reduced in intensity significantly by using 1.0 mL min{sup −1} methane (CH{sub 4}) as reaction cell gas in the dynamic reaction cell (DRC). Since the sensitivities of Cr, Fe, Cu, Zn and Se in different matrices were quite different, standard addition and isotope dilution methods were used for the determination of Cr, Fe, Cu, Zn and Se in these cereal samples. The method detection limits estimated from standard addition curves were about 1, 10, 4, 12 and 2 ng g{sup −1} for Cr, Fe, Cu, Zn and Se, respectively, in original cereal samples. This procedure has been applied to the determination of Cr, Fe, Cu, Zn and Se whose concentrations are in μg g{sup −1} (except Cr and Se) in standard reference materials (SRM) of National institute of standards and technology (NIST), NIST SRM 1568a Rice Flour and NIST SRM 1567a Wheat Flour and two cereal samples purchased from a local market. The analysis results of reference materials agreed with certified values at 95% confidence level according to Student's T-test. The results for the real world cereal samples were also found to be in good agreement with the pneumatic nebulization DRC ICP-MS results of the sample solutions. - Highlights: • Determination of Cr, Fe, Cu, Zn and Se in cereal samples • Ultrasonic slurry sampling in combination with DRC-ICP-MS • Better sensitivity with thioacetamide modifier in ETV • Decreased sample preparation time with solid sampling • Validation with NIST SRM 1568a Rice Flour and NIST SRM 1567a Wheat Flour.

  11. Ultrasonic slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry for the determination of Cr, Fe, Cu, Zn and Se in cereals

    International Nuclear Information System (INIS)

    Huang, Shih-Yi; Jiang, Shiuh-Jen; Sahayam, A.C.

    2014-01-01

    Ultrasonic slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry (USS-ETV-ICP-MS) has been applied to determine Cr, Fe, Cu, Zn and Se in several cereal samples. Thioacetamide was used as the modifier to enhance the ion signals. The background ions at the masses of interest were reduced in intensity significantly by using 1.0 mL min −1 methane (CH 4 ) as reaction cell gas in the dynamic reaction cell (DRC). Since the sensitivities of Cr, Fe, Cu, Zn and Se in different matrices were quite different, standard addition and isotope dilution methods were used for the determination of Cr, Fe, Cu, Zn and Se in these cereal samples. The method detection limits estimated from standard addition curves were about 1, 10, 4, 12 and 2 ng g −1 for Cr, Fe, Cu, Zn and Se, respectively, in original cereal samples. This procedure has been applied to the determination of Cr, Fe, Cu, Zn and Se whose concentrations are in μg g −1 (except Cr and Se) in standard reference materials (SRM) of National institute of standards and technology (NIST), NIST SRM 1568a Rice Flour and NIST SRM 1567a Wheat Flour and two cereal samples purchased from a local market. The analysis results of reference materials agreed with certified values at 95% confidence level according to Student's T-test. The results for the real world cereal samples were also found to be in good agreement with the pneumatic nebulization DRC ICP-MS results of the sample solutions. - Highlights: • Determination of Cr, Fe, Cu, Zn and Se in cereal samples • Ultrasonic slurry sampling in combination with DRC-ICP-MS • Better sensitivity with thioacetamide modifier in ETV • Decreased sample preparation time with solid sampling • Validation with NIST SRM 1568a Rice Flour and NIST SRM 1567a Wheat Flour

  12. 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

  13. 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...

  14. 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.

  15. 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.

  16. 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...

  17. 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

  18. 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

  19. 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.

  20. 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)

  1. Ultrasonic slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry for the determination of Cr, Fe, Cu, Zn and Se in cereals

    Science.gov (United States)

    Huang, Shih-Yi; Jiang, Shiuh-Jen; Sahayam, A. C.

    2014-11-01

    Ultrasonic slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry (USS-ETV-ICP-MS) has been applied to determine Cr, Fe, Cu, Zn and Se in several cereal samples. Thioacetamide was used as the modifier to enhance the ion signals. The background ions at the masses of interest were reduced in intensity significantly by using 1.0 mL min- 1 methane (CH4) as reaction cell gas in the dynamic reaction cell (DRC). Since the sensitivities of Cr, Fe, Cu, Zn and Se in different matrices were quite different, standard addition and isotope dilution methods were used for the determination of Cr, Fe, Cu, Zn and Se in these cereal samples. The method detection limits estimated from standard addition curves were about 1, 10, 4, 12 and 2 ng g- 1 for Cr, Fe, Cu, Zn and Se, respectively, in original cereal samples. This procedure has been applied to the determination of Cr, Fe, Cu, Zn and Se whose concentrations are in μg g- 1 (except Cr and Se) in standard reference materials (SRM) of National institute of standards and technology (NIST), NIST SRM 1568a Rice Flour and NIST SRM 1567a Wheat Flour and two cereal samples purchased from a local market. The analysis results of reference materials agreed with certified values at 95% confidence level according to Student's T-test. The results for the real world cereal samples were also found to be in good agreement with the pneumatic nebulization DRC ICP-MS results of the sample solutions.

  2. [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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  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

    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....

  8. 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....

  9. 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)

  10. 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.

  11. 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...

  12. 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.

  13. 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.)

  14. 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)

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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.

  3. 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...

  4. 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...

  5. 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)

  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. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. A modified anthrax toxin-based enzyme-linked immunospot assay reveals robust T cell responses in symptomatic and asymptomatic Ebola virus exposed individuals.

    Science.gov (United States)

    Herrera, Bobby Brooke; Hamel, Donald J; Oshun, Philip; Akinsola, Rolake; Akanmu, Alani S; Chang, Charlotte A; Eromon, Philomena; Folarin, Onikepe; Adeyemi, Kayode T; Happi, Christian T; Lu, Yichen; Ogunsola, Folasade; Kanki, Phyllis J

    2018-05-01

    Ebola virus (EBOV) caused more than 11,000 deaths during the 2013-2016 epidemic in West Africa without approved vaccines or immunotherapeutics. Despite its high lethality in some individuals, EBOV infection can produce little to no symptoms in others. A better understanding of the immune responses in individuals who experienced minimally symptomatic and asymptomatic infection could aid the development of more effective vaccines and antivirals against EBOV and related filoviruses. Between August and November 2017, blood samples were collected from 19 study participants in Lagos, Nigeria, including 3 Ebola virus disease (EVD) survivors, 10 individuals with documented close contact with symptomatic EVD patients, and 6 control healthcare workers for a cross-sectional serosurvey and T cell analysis. The Lagos samples, as well as archived serum collected from healthy individuals living in surrounding areas of the 1976 Democratic Republic of Congo (DRC) epidemic, were tested for EBOV IgG using commercial enzyme-linked immunosorbent assays (ELISAs) and Western blots. We detected antibodies in 3 out of 3 Lagos survivors and identified 2 seropositive individuals not known to have ever been infected. Of the DRC samples tested, we detected antibodies in 9 out of 71 (12.7%). To characterize the T cell responses in the Lagos samples, we developed an anthrax toxin-based enzyme-linked immunospot (ELISPOT) assay. The seropositive asymptomatic individuals had T cell responses against EBOV nucleoprotein, matrix protein, and glycoprotein 1 that were stronger in magnitude compared to the survivors. Our data provide further evidence of EBOV exposure in individuals without EVD-like illness and, for the first time, demonstrate that these individuals have T cell responses that are stronger in magnitude compared to severe cases. These findings suggest that T cell immunity may protect against severe EVD, which has important implications for vaccine development.

  15. 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.

  16. 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.

  17. 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.

  18. 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)

  19. 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)

  20. Confining Domains Lead to Reaction Bursts: Reaction Kinetics in the Plasma Membrane

    Science.gov (United States)

    Kalay, Ziya; Fujiwara, Takahiro K.; Kusumi, Akihiro

    2012-01-01

    Confinement of molecules in specific small volumes and areas within a cell is likely to be a general strategy that is developed during evolution for regulating the interactions and functions of biomolecules. The cellular plasma membrane, which is the outermost membrane that surrounds the entire cell, was considered to be a continuous two-dimensional liquid, but it is becoming clear that it consists of numerous nano-meso-scale domains with various lifetimes, such as raft domains and cytoskeleton-induced compartments, and membrane molecules are dynamically trapped in these domains. In this article, we give a theoretical account on the effects of molecular confinement on reversible bimolecular reactions in a partitioned surface such as the plasma membrane. By performing simulations based on a lattice-based model of diffusion and reaction, we found that in the presence of membrane partitioning, bimolecular reactions that occur in each compartment proceed in bursts during which the reaction rate is sharply and briefly increased even though the asymptotic reaction rate remains the same. We characterized the time between reaction bursts and the burst amplitude as a function of the model parameters, and discussed the biological significance of the reaction bursts in the presence of strong inhibitor activity. PMID:22479350

  1. Confining domains lead to reaction bursts: reaction kinetics in the plasma membrane.

    Directory of Open Access Journals (Sweden)

    Ziya Kalay

    Full Text Available Confinement of molecules in specific small volumes and areas within a cell is likely to be a general strategy that is developed during evolution for regulating the interactions and functions of biomolecules. The cellular plasma membrane, which is the outermost membrane that surrounds the entire cell, was considered to be a continuous two-dimensional liquid, but it is becoming clear that it consists of numerous nano-meso-scale domains with various lifetimes, such as raft domains and cytoskeleton-induced compartments, and membrane molecules are dynamically trapped in these domains. In this article, we give a theoretical account on the effects of molecular confinement on reversible bimolecular reactions in a partitioned surface such as the plasma membrane. By performing simulations based on a lattice-based model of diffusion and reaction, we found that in the presence of membrane partitioning, bimolecular reactions that occur in each compartment proceed in bursts during which the reaction rate is sharply and briefly increased even though the asymptotic reaction rate remains the same. We characterized the time between reaction bursts and the burst amplitude as a function of the model parameters, and discussed the biological significance of the reaction bursts in the presence of strong inhibitor activity.

  2. 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).

  3. 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.

  4. 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; these reactions show a negative correlation with CD8-positive cytotoxic T cells, suggesting that the evasion of immune surveillance is associated with cytotoxic T cells. The regulatory cytokine IL-10 may induce IgG4-positive plasma cell differentiation or promote B cell switching to IgG4 in the presence of IL-4. Cholangiocarcinoma cells may function as nonprofessional antigen presenting cells that indirectly induce IgG4 reactions via the IL-10-producing cells and/or these may act as Foxp3-positive and IL-10-producing cells that directly induce IgG4 reactions. Moreover, IgG4-related disease is a high-risk factor for cancer development; IgG4-related sclerosing cholangitis (IgG4-SC cases associated with cholangiocarcinoma or its precursor lesion biliary intraepithelial neoplasia (BilIN have been reported. IgG4-positive cell infiltration is an important finding of IgG4-SC but is not a histological hallmark of IgG4-SC. For the diagnosis of IgG4-SC, its differentiation from cholangiocarcinoma remains important.

  5. 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.

  6. 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).

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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,

  15. 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

  16. 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.

  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. 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

  19. 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.

  20. 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.

  1. 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

  2. Identification of Dengue and Chikungunya Cases Among Suspected Cases of Yellow Fever in the Democratic Republic of the Congo.

    Science.gov (United States)

    Makiala-Mandanda, Sheila; Ahuka-Mundeke, Steve; Abbate, Jessica L; Pukuta-Simbu, Elisabeth; Nsio-Mbeta, Justus; Berthet, Nicolas; Leroy, Eric Maurice; Becquart, Pierre; Muyembe-Tamfum, Jean-Jacques

    2018-05-16

    For more than 95% of acute febrile jaundice cases identified through surveillance for yellow fever, a reemerging arthropod-borne viral disease, no etiological exploration is ever done. The aim of this study was to test for other arthropod-borne viruses that can induce the same symptoms in patients enrolled in the yellow fever surveillance in the Democratic Republic of the Congo (DRC). Of 652 patients included in the surveillance of yellow fever in DRC from January 2003 to January 2012, 453 patients that tested negative for yellow fever virus (YFV) immunoglobulin M (IgM) antibodies were selected for the study. Real-time polymerase chain reaction was performed for the detection of dengue, West Nile, Chikungunya, O'nyong-nyong, Rift Valley fever, Zika, and YFV. The average age of patients was 22.1 years. We reported 16 cases (3.5%; confidence interval [CI]: 0.8-5.2) of dengue (serotypes 1 and 2) and 2 cases (0.4%; CI: 0.0-1.0) of Chikungunya. Three patients were co-infected with the two serotypes of dengue virus. Three cases of dengue were found in early July 2010 from the city of Titule (Oriental province) during a laboratory-confirmed outbreak of yellow fever, suggesting simultaneous circulation of dengue and yellow fever viruses. This study showed that dengue and Chikungunya viruses are potential causes of acute febrile jaundice in the DRC and highlights the need to consider dengue and Chikungunya diagnosis in the integrated disease surveillance and response program in the DRC. A prospective study is necessary to establish the epidemiology of these diseases.

  3. A novel differential electrochemical mass spectrometry method to determine the product distribution from parasitic Methanol oxidation reaction on oxygen reduction reaction catalysts

    Science.gov (United States)

    Jurzinsky, Tilman; Kurzhals, Philipp; Cremers, Carsten

    2018-06-01

    The oxygen reduction reaction is in research focus since several decades due to its importance for the overall fuel cell performance. In direct methanol fuel cells, the crossover of methanol and its subsequent parasitic oxidation are main issues when it comes to preventing fuel cell performance losses. In this work, we present a novel differential electrochemical mass spectrometry method to evaluate oxygen reduction reaction catalysts on their tolerance to methanol being present at the cathode. Besides this, the setup allows to measure under more realistic fuel cell conditions than typical rotating disc electrode measurements, because the oxygen reduction reaction is evaluated in gaseous phase and a gas diffusion electrode is used as working electrode. Due to the new method, it was possible to investigate the oxygen reduction reaction on two commonly used catalysts (Pt/C and Pt3Co/C) in absence and presence of methanol. It was found, that Pt3Co/C is less prone to parasitic current losses due to methanol oxidation reaction. By connecting a mass spectrometer to the electrochemical cell, the new method allows to determine the products formed on the catalysts due to parasitic methanol electrooxidation.

  4. 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...

  5. 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.

  6. 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)

  7. 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

  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. 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.

  10. 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.

  11. 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)

  12. 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.

  13. Simultaneous speciation of arsenic, selenium, and chromium: Species stability, sample preservation, and analysis of ash and soil leachates

    Science.gov (United States)

    Wolf, R.E.; Morman, S.A.; Hageman, P.L.; Hoefen, T.M.; Plumlee, G.S.

    2011-01-01

    An analytical method using high-performance liquid chromatography separation with inductively coupled plasma mass spectrometry (ICP-MS) detection previously developed for the determination of Cr(III) and Cr(VI) has been adapted to allow the determination of As(III), As(V), Se(IV), Se(VI), Cr(III), and Cr(VI) under the same chromatographic conditions. Using this method, all six inorganic species can be determined in less than 3 min. A dynamic reaction cell (DRC)-ICP-MS system was used to detect the species eluted from the chromatographic column in order to reduce interferences. A variety of reaction cell gases and conditions may be utilized with the DRC-ICP-MS, and final selection of conditions is determined by data quality objectives. Results indicated all starting standards, reagents, and sample vials should be thoroughly tested for contamination. Tests on species stability indicated that refrigeration at 10 ??C was preferential to freezing for most species, particularly when all species were present, and that sample solutions and extracts should be analyzed as soon as possible to eliminate species instability and interconversion effects. A variety of environmental and geological samples, including waters and deionized water [leachates] and simulated biological leachates from soils and wildfire ashes have been analyzed using this method. Analytical spikes performed on each sample were used to evaluate data quality. Speciation analyses were conducted on deionized water leachates and simulated lung fluid leachates of ash and soils impacted by wildfires. These results show that, for leachates containing high levels of total Cr, the majority of the chromium was present in the hexavalent Cr(VI) form. In general, total and hexavalent chromium levels for samples taken from burned residential areas were higher than those obtained from non-residential forested areas. Arsenic, when found, was generally in the more oxidized As(V) form. Selenium (IV) and (VI) were present

  14. Simultaneous speciation of arsenic, selenium, and chromium: species, stability, sample preservation, and analysis of ash and soil leachates

    Science.gov (United States)

    Wolf, Ruth E.; Morman, Suzette A.; Hageman, Philip L.; Hoefen, Todd M.; Plumlee, Geoffrey S.

    2011-01-01

    An analytical method using high-performance liquid chromatography separation with inductively coupled plasma mass spectrometry (ICP-MS) detection previously developed for the determination of Cr(III) and Cr(VI) has been adapted to allow the determination of As(III), As(V), Se(IV), Se(VI), Cr(III), and Cr(VI) under the same chromatographic conditions. Using this method, all six inorganic species can be determined in less than 3 min. A dynamic reaction cell (DRC)-ICP-MS system was used to detect the species eluted from the chromatographic column in order to reduce interferences. A variety of reaction cell gases and conditions may be utilized with the DRC-ICP-MS, and final selection of conditions is determined by data quality objectives. Results indicated all starting standards, reagents, and sample vials should be thoroughly tested for contamination. Tests on species stability indicated that refrigeration at 10° C was preferential to freezing for most species, particularly when all species were present, and that sample solutions and extracts should be analyzed as soon as possible to eliminate species instability and interconversion effects. A variety of environmental and geological samples, including waters and deionized water [leachates] and simulated biological leachates from soils and wildfire ashes have been analyzed using this method. Analytical spikes performed on each sample were used to evaluate data quality. Speciation analyses were conducted on deionized water leachates and simulated lung fluid leachates of ash and soils impacted by wildfires. These results show that, for leachates containing high levels of total Cr, the majority of the chromium was present in the hexavalent Cr(VI) form. In general, total and hexavalent chromium levels for samples taken from burned residential areas were higher than those obtained from non-residential forested areas. Arsenic, when found, was generally in the more oxidized As(V) form. Selenium (IV) and (VI) were present

  15. Simultaneous speciation of arsenic, selenium, and chromium: species stability, sample preservation, and analysis of ash and soil leachates

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Ruth E.; Morman, Suzette A.; Hageman, Philip L.; Hoefen, Todd M.; Plumlee, Geoffrey S. [Denver Federal Center, US Geological Survey, Denver, CO (United States)

    2011-11-15

    An analytical method using high-performance liquid chromatography separation with inductively coupled plasma mass spectrometry (ICP-MS) detection previously developed for the determination of Cr(III) and Cr(VI) has been adapted to allow the determination of As(III), As(V), Se(IV), Se(VI), Cr(III), and Cr(VI) under the same chromatographic conditions. Using this method, all six inorganic species can be determined in less than 3 min. A dynamic reaction cell (DRC)-ICP-MS system was used to detect the species eluted from the chromatographic column in order to reduce interferences. A variety of reaction cell gases and conditions may be utilized with the DRC-ICP-MS, and final selection of conditions is determined by data quality objectives. Results indicated all starting standards, reagents, and sample vials should be thoroughly tested for contamination. Tests on species stability indicated that refrigeration at 10 C was preferential to freezing for most species, particularly when all species were present, and that sample solutions and extracts should be analyzed as soon as possible to eliminate species instability and interconversion effects. A variety of environmental and geological samples, including waters and deionized water [leachates] and simulated biological leachates from soils and wildfire ashes have been analyzed using this method. Analytical spikes performed on each sample were used to evaluate data quality. Speciation analyses were conducted on deionized water leachates and simulated lung fluid leachates of ash and soils impacted by wildfires. These results show that, for leachates containing high levels of total Cr, the majority of the chromium was present in the hexavalent Cr(VI) form. In general, total and hexavalent chromium levels for samples taken from burned residential areas were higher than those obtained from non-residential forested areas. Arsenic, when found, was generally in the more oxidized As(V) form. Selenium (IV) and (VI) were present, but

  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. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. Fitting modular reconnaissance systems into modern high-performance aircraft

    Science.gov (United States)

    Stroot, Jacquelyn R.; Pingel, Leslie L.

    1990-11-01

    The installation of the Advanced Tactical Air Reconnaissance System (ATARS) in the F/A-18D(RC) presented a complex set of design challenges. At the time of the F/A-18D(RC) ATARS option exercise, the design and development of the ATARS subsystems and the parameters of the F/A-18D(RC) were essentially fixed. ATARS is to be installed in the gun bay of the F/A-18D(RC), taking up no additional room, nor adding any more weight than what was removed. The F/A-18D(RC) installation solution required innovations in mounting, cooling, and fit techniques, which made constant trade study essential. The successful installation in the F/A-18D(RC) is the result of coupling fundamental design engineering with brainstorming and nonstandard approaches to every situation. ATARS is sponsored by the Aeronautical Systems Division, Wright-Patterson AFB, Ohio. The F/A-18D(RC) installation is being funded to the Air Force by the Naval Air Systems Command, Washington, D.C.

  4. Evaluation of bovine rumen contents as a feed for lambs.

    Science.gov (United States)

    Olafadehan, Olurotimi Ayobami; Okunade, Sunday Adewale; Njidda, Ahmed Amin

    2014-08-01

    This study evaluated effects of increasing levels of dried rumen contents (DRC) on voluntary intake, growth performance, digestibility, nutritive value, N utilization, microbial protein supply (MPS), and purine derivatives excretion (PDE) of lambs fed with Afzelia africana basal forage. Sixteen lambs (13.7 ± 0.1 kg body weight (BW)) were randomly assigned to one of the four eight diets containing 0, 200, 400 and 600 g DRC/kg dry matter (DM) in a completely random design. Intakes of concentrate, DM, crude protein (CP), organic matter (OM), digestible CP (DCP), digestible OM (DOM), digestible energy (DE) and metabolizable energy (ME), CP and OM digestibility, DOM, DCP, DE, ME, N intake and retention, weight gain, cost/kg BW gain, MPS and PDE increased with increasing DRC level up to 400 g/kg DRC and declined at 600 g/kg DRC (P level increased from 0 to 400 g/kg and peaked at 600 g/kg DRC (P level. Results indicate that DRC can be incorporated up to 400 g/kg in a compounded ration for sheep.

  5. 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

  6. 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

  7. 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

  8. 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)

  9. 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.

  10. 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

  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. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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 ...

  19. 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.

  20. 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.

  1. 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.

  2. Immediate and delayed cutaneous reactions to radiocontrast media.

    Science.gov (United States)

    Brockow, Knut

    2012-01-01

    Hypersensitivity reactions to contrast media (CM) are frequent causes of anaphylaxis and drug exanthemas. Adverse events after CM exposure are classified into immediate (≤1 h) and non-immediate reactions (>1 h), with differing mechanisms. In the majority of patients with immediate reactions, IgE-mediated allergy cannot be demonstrated, and the underlying mechanism remains unknown. However, recent data have provided evidence for skin test positivity and/or specific IgE in some patients. T cell-mediated hypersensitivity is the responsible mechanism for the majority of non-immediate skin eruptions. These insights have consequences for diagnosis and prevention. Skin testing evolves to be a useful tool for diagnosis of CM allergy. Skin tests have been employed to confirm this hypersensitivity. Previous reactors have an increased risk to develop new reactions upon repeated exposure; however, other risk factors are poorly defined. The use of skin tests for the selection of a 'safe' CM is under investigation with promising results. In vitro tests to search for CM-specific cell activation include flow cytometric approaches, lymphocyte cultures and construction of cell lines and hybridomas. Premedication of previous reactors is common practice among radiologists; however, breakthrough reactions are a concern, and physicians should not rely on the efficacy of pharmacological premedication. Copyright © 2012 S. Karger AG, Basel.

  3. 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.

  4. 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.

  5. Determination of rate constants for the oxygen reduction reaction

    Energy Technology Data Exchange (ETDEWEB)

    Racz, A.; Walter, T.; Stimming, U. [Munich Technical Univ., Garching (Germany). Dept. of Physics

    2008-07-01

    The oxygen reduction reaction (ORR) in fuel cells is a complex and fundamental electrochemical reaction. However, greater insight is needed into this multi-electron reaction in order to develop efficient and innovative catalysts. The rotating ring disc electrode (RRDE) is a useful tool for studying reaction intermediates of the ORR and to better understand the reaction pathway. Carbon materials such as carbon nanofilaments-platelets (CNF-PL) have high electrical conductivity and may be considered for fuel cells. In particular Pt and RuSe{sub x}, deposited on CNF-PL materials could act as efficient catalysts in fuel cells. This study used the RRDE to evaluate the oxygen reduction kinetics of these catalysts in oxygen-saturated, diluted sulphuric acid at room temperature. Kinetic data and hydrogen peroxide formation were determined by depositing a thin-film of the catalyst on the Au disc. The values for the constants k1, k2 and k3 were obtained using diagnostic criteria and expressions to calculate the rate constants of the cathodic oxygen reduction reaction for RuSe on new carbon supports. A potential dependency of the constants k1 and k2 for RuSe{sub x}/CNF-PL was observed. The transition of the Tafel slopes for this catalyst was obtained. 4 refs., 1 fig.

  6. 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.

  7. 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.

  8. 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

  9. Reaction-diffusion systems in intracellular molecular transport and control.

    Science.gov (United States)

    Soh, Siowling; Byrska, Marta; Kandere-Grzybowska, Kristiana; Grzybowski, Bartosz A

    2010-06-07

    Chemical reactions make cells work only if the participating chemicals are delivered to desired locations in a timely and precise fashion. Most research to date has focused on active-transport mechanisms, although passive diffusion is often equally rapid and energetically less costly. Capitalizing on these advantages, cells have developed sophisticated reaction-diffusion (RD) systems that control a wide range of cellular functions-from chemotaxis and cell division, through signaling cascades and oscillations, to cell motility. These apparently diverse systems share many common features and are "wired" according to "generic" motifs such as nonlinear kinetics, autocatalysis, and feedback loops. Understanding the operation of these complex (bio)chemical systems requires the analysis of pertinent transport-kinetic equations or, at least on a qualitative level, of the characteristic times of the constituent subprocesses. Therefore, in reviewing the manifestations of cellular RD, we also describe basic theory of reaction-diffusion phenomena.

  10. 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.

  11. Basic reactions of osteoblasts on structured material surfaces

    Directory of Open Access Journals (Sweden)

    U. Meyer

    2005-04-01

    Full Text Available In order to assess how bone substitute materials determine bone formation in vivo it is useful to understand the mechanisms of the material surface/tissue interaction on a cellular level. Artificial materials are used in two applications, as biomaterials alone or as a scaffold for osteoblasts in a tissue engineering approach. Recently, many efforts have been undertaken to improve bone regeneration by the use of structured material surfaces. In vitro studies of bone cell responses to artificial materials are the basic tool to determine these interactions. Surface properties of materials surfaces as well as biophysical constraints at the biomaterial surface are of major importance since these features will direct the cell responses. Studies on osteoblast-like cell reactivity towards materials will have to focus on the different steps of protein and cell reactions towards defined surface properties. The introduction of new techniques allows nowadays the fabrication of materials with ordered surface structures. This paper gives a review of present knowledge on the various stages of osteoblast reactions on material surfaces, focused on basic cell events under in vitro conditions. Special emphasis is given to cellular reactions towards ordered nano-sized topographies.

  12. Investigation of reaction equilibrium in reactor materials by EMF methods

    International Nuclear Information System (INIS)

    Ullmann, H.; Teske, K.; Reetz, T.; Rettig, D.; Kozlov, F.A.; Kuznecov, E.K.

    1979-01-01

    By means of electrochemical cells with solid electrolytes measurements of the chemical activities of oxygen and hydrogen in a sodium test loop were performed. The reaction equilibrium of oxygen and hydrogen in dilute solutions of sodium was investigated. The activities of both oxygen and hydrogen decrease with increasing concentration of the reaction partner. From the relation between the activivy of one component and the analytic concentration of the reaction partner the equilibrium constant of the reaction 0+H = OH was determinded to lg K sub(diss) = -(1,502+-0,216)-(1356+-140)/T. An electrochemical cell with an iron membrane and a solid electrolyte was used to measure the activity of carbon in a carborizing medium. The cell output was stable over a period of more than 1000 hours at a carbon activity of 1. (orig.) [de

  13. 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.

  14. 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.

  15. Serum Trace Elements and Electrolytes Are Associated with Fasting Plasma Glucose and HbA1c in Postmenopausal Women with Type 2 Diabetes Mellitus.

    Science.gov (United States)

    Skalnaya, Margarita G; Skalny, Anatoly V; Yurasov, Vasily V; Demidov, Vasily A; Grabeklis, Andrei R; Radysh, Ivan V; Tinkov, Alexey A

    2017-05-01

    The primary aim of the research was to assess the level of trace elements and electrolytes in serum of postmenopausal diabetic women. Sixty-four postmenopausal women with type 2 diabetes mellitus (DM2) and 64 age- and body mass index-matched controls were examined. Serum trace elements were assessed using inductively coupled plasma dynamic reaction cell mass spectrometry (ICP-DRC-MS). Fasting plasma glucose (FPG) and glycated hemoglobin (HbA 1c ) levels were evaluated using Randox kits. The obtained data demonstrate that DM2 patients were characterized by 42 and 34 % higher FPG and HbA 1c levels, respectively (p women was increased by 10 and 15 % in comparison to the respective control values (p = 0.002 and DM2 pathogenesis. Further studies are required to assess the intimate mechanisms of the observed differences.

  16. Speciation of selenoamino acids, selenonium ions and inorganic selenium by ion exchange HPLC with mass spectrometric detection and its application to yeast and algae

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Hansen, M.; Fan, T.

    2001-01-01

    Cation and anion exchange HPLC were used to separate a mixture of 12 selenium species comprising selenoamino acids, selenonium ions and inorganic selenium. The cationic species were separated from each other and from the co-injected anions using a cation exchange column with gradient elution...... by aqueous pyridinium formate at pH similar to 3 as the mobile phase. The anionic species were separated using an anion exchange column with isocratic elution by an aqueous salicylate-TRIS mobile phase at pH 8.5. The separated selenium species were detected as Se-80 by ICP-dynamic reaction cell (DRC...... acid extract of Chlorella algae contained dimethylselenonium propionate (DMSeP), which was verified by HPLC-ES-MS. Se-allylselenocysteine and selenoethionine was detected at the low ng g(-1) concentration level based on co-chromatography with the standard substances spiked to the algal extract....

  17. Nonimmediate hypersensitivity reactions to iodinated contrast media.

    Science.gov (United States)

    Gómez, Enrique; Ariza, Adriana; Blanca-López, Natalia; Torres, Maria J

    2013-08-01

    To provide a detailed analysis of the latest findings on the mechanisms underlying the nonimmediate reactions to iodinated contrast media and comment on the recent advances in diagnosis, focusing on the roles of the skin test, drug provocation test (DPT), and lymphocyte transformation test (LTT). Several studies have reported new findings supporting an important role for T-lymphocytes in the nonimmediate reactions to iodinated contrast media. The LTT has been used as an in-vitro tool for diagnosis, but with variable results. However, the inclusion of autologous monocyte-derived dendritic cells as professional antigen-presenting cells has improved the sensitivity of this test. Regarding in-vivo diagnosis, although skin testing has been routine, it has now been shown that its sensitivity and negative predictive value are low. Recent studies have demonstrated that the DPT is a well tolerated and useful procedure that is necessary to confirm the diagnosis of nonimmediate hypersensitivity reactions to iodinated contrast media. Nonimmediate reactions to contrast media are usually T-cell mediated. Diagnosis is based on skin testing, although its sensitivity and negative predictive value are not optimal. Consequently, drug provocation testing is often needed to confirm the diagnosis and also to seek alternative contrast media that can be tolerated.

  18. 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.

  19. Study of quantitative analysis of rare earth elements (Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) in soil samples by inductively couple plasma mass spectrometry

    International Nuclear Information System (INIS)

    Truong Duc Toan; Nguyen Giang; Vo Tran Quang Thai; Do Tam Nhan; Nguyen Le Anh; Nguyen Viet Duc; Luong Thi Tham; Truong Thi Phuong Mai

    2015-01-01

    Method for the determination of 16 rare earth elements (REEs) in soil samples without separating by inductively coupled plasma mass spectrometry (ICP-MS) has been studied at Dalat Nuclear Research Institute. The optimal conditions for ICP-MS NexION 300X with three modes: Standard, Collision (KED), and Reaction (DRC) have been studied on the Montana II soil reference material. The result analysis shows that: DRC mode only gives good analysis result for Sc, Y, La, Ce, Pr, Nd, Tm, Yb, and Lu; Standard mode exhibits good analysis results for all elements with error from 1.2 - 29.0% and KED mode is the best one with error less than 15%. The concentrations of elements in the soil samples of Cau Dat, Bao Loc, and Da Lat were determined, which concentrations of REEs in soil samples of Cau Dat are higher than that of the other areas in Lam Dong Province. (author)

  20. 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).

  1. 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

  2. High performance platinum single atom electrocatalyst for oxygen reduction reaction

    Science.gov (United States)

    Liu, Jing; Jiao, Menggai; Lu, Lanlu; Barkholtz, Heather M.; Li, Yuping; Wang, Ying; Jiang, Luhua; Wu, Zhijian; Liu, Di-Jia; Zhuang, Lin; Ma, Chao; Zeng, Jie; Zhang, Bingsen; Su, Dangsheng; Song, Ping; Xing, Wei; Xu, Weilin; Wang, Ying; Jiang, Zheng; Sun, Gongquan

    2017-07-01

    For the large-scale sustainable implementation of polymer electrolyte membrane fuel cells in vehicles, high-performance electrocatalysts with low platinum consumption are desirable for use as cathode material during the oxygen reduction reaction in fuel cells. Here we report a carbon black-supported cost-effective, efficient and durable platinum single-atom electrocatalyst with carbon monoxide/methanol tolerance for the cathodic oxygen reduction reaction. The acidic single-cell with such a catalyst as cathode delivers high performance, with power density up to 680 mW cm-2 at 80 °C with a low platinum loading of 0.09 mgPt cm-2, corresponding to a platinum utilization of 0.13 gPt kW-1 in the fuel cell. Good fuel cell durability is also observed. Theoretical calculations reveal that the main effective sites on such platinum single-atom electrocatalysts are single-pyridinic-nitrogen-atom-anchored single-platinum-atom centres, which are tolerant to carbon monoxide/methanol, but highly active for the oxygen reduction reaction.

  3. Cellular reprogramming dynamics follow a simple 1D reaction coordinate

    Science.gov (United States)

    Teja Pusuluri, Sai; Lang, Alex H.; Mehta, Pankaj; Castillo, Horacio E.

    2018-01-01

    Cellular reprogramming, the conversion of one cell type to another, induces global changes in gene expression involving thousands of genes, and understanding how cells globally alter their gene expression profile during reprogramming is an ongoing problem. Here we reanalyze time-course data on cellular reprogramming from differentiated cell types to induced pluripotent stem cells (iPSCs) and show that gene expression dynamics during reprogramming follow a simple 1D reaction coordinate. This reaction coordinate is independent of both the time it takes to reach the iPSC state as well as the details of the experimental protocol used. Using Monte-Carlo simulations, we show that such a reaction coordinate emerges from epigenetic landscape models where cellular reprogramming is viewed as a ‘barrier-crossing’ process between cell fates. Overall, our analysis and model suggest that gene expression dynamics during reprogramming follow a canonical trajectory consistent with the idea of an ‘optimal path’ in gene expression space for reprogramming.

  4. 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.

  5. Detailed analysis of allergic cutaneous reactions to spinal cord stimulator devices

    Directory of Open Access Journals (Sweden)

    Chaudhry ZA

    2013-08-01

    Full Text Available Zeshan Ahmed Chaudhry,1 Umer Najib,2 Zahid H Bajwa,3 W Carl Jacobs,4 Javed Sheikh,5 Thomas T Simopoulos61Department of Diagnostic and Interventional Neuroradiology, Massachusetts General Hospital/Harvard Medical School, Boston, MA, USA; 2Department of Neurology, Robert C Byrd Health Sciences Center of West Virginia University, Morgantown, WV, USA; 3Boston Headache Institute, Waltham, MA, USA; 4Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; 5Department of Medicine, Allergy and Immunology, 6Department of Anesthesia, Beth Israel Deaconess Medical Center, Brookline, MA, USAAbstract: The use of spinal cord stimulation (SCS devices to treat chronic, refractory neuropathic pain continues to expand in application. While device-related complications have been well described, inflammatory reactions to the components of these devices remain underreported. In contrast, hypersensitivity reactions associated with other implanted therapies, such as endovascular and cardiac rhythm devices, have been detailed. The purpose of this case series is to describe the clinical presentation and course of inflammatory reactions as well as the histology of these reactions. All patients required removal of the entire device after developing inflammatory reactions over a time course of 1–3 months. Two patients developed a foreign body reaction in the lead insertion wound as well as at the implantable pulse generator site, with histology positive for giant cells. One patient developed an inflammatory dermatitis on the flank and abdomen that resolved with topical hydrocortisone. “In vivo” testing with a lead extension fragment placed in the buttock resulted in a negative reaction followed by successful reimplantation of an SCS device. Inflammatory reactions to SCS devices can manifest as contact dermatitis, granuloma formation, or foreign body reactions with giant cell formation. Tissue diagnosis is essential, and

  6. 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.

  7. Electrothermal vaporization inductively coupled plasma-mass spectrometry for the determination of Cr, Cu, Cd, Hg and Pb in rice flour

    International Nuclear Information System (INIS)

    Li, P.-C.; Jiang, S.-J.

    2003-01-01

    Ultrasonic slurry sampling (USS)-electrothermal vaporization (ETV) dynamic reaction cell TM (DRC) inductively coupled plasma-mass spectrometry (ICP-MS) has been applied to determine Cr, Cu, Cd, Hg and Pb in rice samples. The influences of instrument operating conditions and slurry preparation on the ion signals were reported. Ascorbic acid was used as a modifier to enhance the ion signals. The background ions at the chromium masses were reduced in intensity significantly by using 0.4 ml min -1 NH 3 as reaction cell gas in the dynamic reaction cell while a q value of 0.6 was used. Since the sensitivities of Cr, Cu, Cd, Hg and Pb in rice flour slurry and aqueous solution were quite different, standard addition and isotope dilution methods were used for the determination of Cr, Cu, Cd, Hg and Pb in these rice samples. This method has been applied to the determination of Cr, Cu, Cd, Hg and Pb in NIST SRM 1568a rice flour reference material and two rice samples purchased from the market. The analytical results for the reference material agreed with the certified values. The results for the rice samples for which no reference values were available were also found to be in good agreement between the isotope dilution and standard addition methods. The method's detection limits estimated from the standard addition plots were about 0.44, 1.7, 0.4, 0.53 and 0.69 ng g -1 for Cr, Cu, Cd, Hg and Pb, respectively, in the original rice flour

  8. 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.

  9. Anti-M causing delayed hemolytic transfusion reaction

    International Nuclear Information System (INIS)

    Alperin, J.B.; Riglin, H.; Branch, D.R.; Gallagher, M.T.; Petz, L.D.

    1983-01-01

    A 52-year-old gravida 1, para 1 woman with M- red cells experienced a delayed hemolytic transfusion reaction and exhibited an anti-M antibody following the infusion of four units of M+ red cells. Measurements of erythrocyte survival using 51 Cr-labeled donor M+ and M- red cells and in vitro studies of monocyte-macrophage phagocytosis of sensitized reagent red cells implicate anti-M in the pathogenesis of hemolysis

  10. Direct synthesis of bimetallic PtCo mesoporous nanospheres as efficient bifunctional electrocatalysts for both oxygen reduction reaction and methanol oxidation reaction

    Science.gov (United States)

    Wang, Hongjing; Yu, Hongjie; Li, Yinghao; Yin, Shuli; Xue, Hairong; Li, Xiaonian; Xu, You; Wang, Liang

    2018-04-01

    The engineering of electrocatalysts with high performance for cathodic and/or anodic catalytic reactions is of great urgency for the development of direct methanol fuel cells. Pt-based bimetallic alloys have recently received considerable attention in the field of fuel cells because of their superior catalytic performance towards both fuel molecule electro-oxidation and oxygen reduction. In this work, bimetallic PtCo mesoporous nanospheres (PtCo MNs) with uniform size and morphology have been prepared by a one-step method with a high yield. The as-made PtCo MNs show superior catalytic activities for both oxygen reduction reaction and methanol oxidation reaction relative to Pt MNs and commercial Pt/C catalyst, attributed to their mesoporous structure and bimetallic composition.

  11. 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.

  12. Renal scintigraphy with DMSA 99 mTc and the direct radionuclide cystogram in children with recurrent urinary tract infections

    International Nuclear Information System (INIS)

    Donoso R, Gilda; Lobo S, Gabriel; Arteaga V, Maria de la Paz; Arnello V, Francisca; Jimenez, Cesar; Perez, Andres

    2003-01-01

    The aim of this study was to correlate the results of Renal Scintigraphy (RS) and the Direct Radionuclide Cystogram (DRC) in children with recurrent urinary tract infections. Method: we analyse 92 children, 82 % females , with ages ranging from 1 month- 12 years old (mean:4,3 years old). Both techniques were performed conventionally with a gammacamera/ computer system. We determined the concordance or discordance between them, and the positive and negative predictive value (PPV, NPV ) of one method with respect the other. For statistical analysis we use Chi square and MacNemar test. Results: 45 % of the RS were abnormal, and the 27 % of DRC was positive. We found a concordance of the results in both techniques in 70 % (p< 0.001) .For the RS vs DRC the PPV was 46% and the NPV was 88%. For the DRC vs RS the PPV was the 76 % and the NPV was 67%. Conclusions. 1.- : 1.- the normality of RS is a better predictor of normality than DRC. 2.-The abnormality of DRC predicts better the abnormality of RS than the inverse. 3.- The results of both techniques show a significant concordance (author)

  13. Genetic Evidence of Importation of Drug-Resistant Plasmodium falciparum to Guatemala from the Democratic Republic of the Congo.

    Science.gov (United States)

    Patel, Jaymin C; Taylor, Steve M; Juliao, Patricia C; Parobek, Christian M; Janko, Mark; Gonzalez, Luis Demetrio; Ortiz, Lucia; Padilla, Norma; Tshefu, Antoinette K; Emch, Michael; Udhayakumar, Venkatachalam; Lindblade, Kim; Meshnick, Steven R

    2014-06-01

    Imported malaria threatens control and elimination efforts in countries that have low rates of transmission. In 2010, an outbreak of Plasmodium falciparum malaria was reported among United Nations peacekeeping soldiers from Guatemala who had recently returned from the Democratic Republic of the Congo (DRC). Epidemiologic evidence suggested that the soldiers were infected in the DRC, but local transmission could not be ruled out in all cases. We used population genetic analyses of neutral microsatellites to determine the outbreak source. Genetic relatedness was compared among parasites found in samples from the soldiers and parasite populations collected in the DRC and Guatemala; parasites identified in the soldiers were more closely related to those from the DRC. A phylogenetic clustering analysis confirms this identification with >99.9% confidence. Thus, results support the hypothesis that the soldiers likely imported malaria from the DRC. This study demonstrates the utility of molecular genotyping in outbreak investigations.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. Extracting reaction networks from databases-opening Pandora's box.

    Science.gov (United States)

    Fearnley, Liam G; Davis, Melissa J; Ragan, Mark A; Nielsen, Lars K

    2014-11-01

    Large quantities of information describing the mechanisms of biological pathways continue to be collected in publicly available databases. At the same time, experiments have increased in scale, and biologists increasingly use pathways defined in online databases to interpret the results of experiments and generate hypotheses. Emerging computational techniques that exploit the rich biological information captured in reaction systems require formal standardized descriptions of pathways to extract these reaction networks and avoid the alternative: time-consuming and largely manual literature-based network reconstruction. Here, we systematically evaluate the effects of commonly used knowledge representations on the seemingly simple task of extracting a reaction network describing signal transduction from a pathway database. We show that this process is in fact surprisingly difficult, and the pathway representations adopted by various knowledge bases have dramatic consequences for reaction network extraction, connectivity, capture of pathway crosstalk and in the modelling of cell-cell interactions. Researchers constructing computational models built from automatically extracted reaction networks must therefore consider the issues we outline in this review to maximize the value of existing pathway knowledge. © The Author 2013. Published by Oxford University Press.

  20. 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.

  1. 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.

  2. Clinical categories of exaggerated skin reactions to mosquito bites and their pathophysiology.

    Science.gov (United States)

    Tatsuno, Kazuki; Fujiyama, Toshiharu; Matsuoka, Hiroyuki; Shimauchi, Takatoshi; Ito, Taisuke; Tokura, Yoshiki

    2016-06-01

    Mosquito bites are skin irritating reactions, which usually resolve spontaneously without intensive medical care. However, in certain situations, mosquito bites may form a more vicious reaction, sometimes accompanying fever and systemic symptoms. In such cases, the presence of rare hematological disorders, abnormalities in eosinophils and/or association with Epstein-Barr virus (EBV) may underlie. Importantly, hypersensitivity to mosquito bites (HMB), which is characterized by necrotic skin reactions to mosquito bites with various systemic symptoms, is often observed in association with EBV infection and natural killer (NK) cell lymphoproliferative disorder. Exaggerated skin reaction to mosquito bites is also seen in Wells' syndrome. While strong Th2-skewing immune dysregulation is apparent in the patients, they also show robust CD4(+) T cell proliferation in response to mosquito salivary gland extracts, indicating close association between Wells' syndrome and mosquito bites. Similar skin reaction to mosquito bites is also noticed in certain types of B cell neoplasm, although the role of B cells in this peculiar reaction to mosquito bites is yet to be elucidated. In this review, we will discuss the current knowledge of exaggerated reaction toward mosquito bites seen in conjunction with these unique hematological disorders, and examine the scientific studies and observations reported in previous literatures to organize our current understanding of the pathogenesis of this distinct disorder. Copyright © 2016 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  3. 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)

  4. 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...

  5. Oral lichenoid reaction to tobacco | Panta | Pan African Medical ...

    African Journals Online (AJOL)

    A differential diagnosis of lichen planus, oral lichenoid reaction and discoid lupus erythematosis were considered. On microscopic examination, there was focal perivascular infiltrate and plasma cells in the connective tissue. After correlating clinically, a diagnosis of "lichenoid reaction" was confirmed. Oral lichenoid ...

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.)

  11. 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

  12. 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.

  13. 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.

  14. Die oor-en-weer beroep van predikante tussen die Nederduitse Gereformeerde Kerk en die Nederduitsch Hervormde Kerk van Afrika: 1862–1917

    Directory of Open Access Journals (Sweden)

    Flip du Toit

    2015-09-01

    Full Text Available The ongoing appointment of ministers between the Dutch Reformed Church and the Netherdutch Reformed Church of Africa: 1862–1917. This article highlights the situation prior to the establishment of the theological training of the Netherdutch Reformed Church of Africa (NDRCA. The training of ministers of the Dutch Reformed Church (DRC started in 1859 with the establishment of the Theological Seminary at Stellenbosch. Since 1862 three churches operated in the then Transvaal (South African Republic. Many ministers of the DRC were called to serve in the NDRCA. The most notable were the Rev D.P. Ackerman and the Rev H.S. Bosman. They were called before the origin of the united church (of the NDRCA and the DRC that existed between 1885 and 1892. After the split in 1892, they (as well as many others continued as ministers in the DRC. The first lecturer of the NDRCA was called in 1917 − also a minister that was previously from the DRC. The calling of his successor sparked a major row. The NDRCA congregation of Pretoria called another minister from the DRC – the Rev H.D. van Broekhuizen. This eventually led to a special meeting of the General Assembly of the NDRCA in 1917 where his calling was eventually approved.

  15. Characterizing pediatric surgical capacity in the Eastern Democratic Republic of Congo: results of a pilot study.

    Science.gov (United States)

    Cairo, Sarah B; Kalisya, Luc Malemo; Bigabwa, Richard; Rothstein, David H

    2018-03-01

    Characterize pediatric surgical capacity in the eastern Democratic Republic of Congo (DRC) to identify areas of potential improvement. The Pediatric Personnel, Infrastructure, Procedures, Equipment, and Supplies (PediPIPES) survey was used in two representative eastern DRC provinces to assess existing surgical infrastructure and capacity. We compared our results to previously published reports from other sub-Saharan African countries. Fourteen hospitals in the eastern DRC and 37 in 19 sub-Saharan African (SSA) countries were compared. The average PediPIPES index for the DRC was 7.7 compared to 13.5 for SSAs. The greatest disparities existed in the areas of personnel and infrastructure. Running water was reportedly available to 57.1% of the hospitals in the DRC, and the majority of hospitals (78.6%) were dependent on generators and solar panels for electricity. Only two hospitals in the DRC (14.3%) reported a pediatric surgeon equivalent on staff, compared to 86.5% of facilities sampled in SSA reporting ≥ 1 pediatric surgeon. Significant barriers in personnel, infrastructure, procedures, equipment, and supplies impede the provision of adequate surgical care to children. Further work is needed to assess allocation and utilization of existing resources, and to enhance training of personnel with specific attention to pediatric surgery.

  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. Avoidance of graft versus host reactions in cured W-anemic mice

    International Nuclear Information System (INIS)

    Harrison, D.E.

    1976-01-01

    Graft-versus-host reactions of parental cells in F 1 hybrids were studied with two unrelated inbred strains of mice that differed at the mouse major histocompatibility locus. W-anemic F 1 recipients were compared with lethally irradiated normal F 1 recipients. Both sets of recipients were populated by marrow and spleen cell grafts from parental and F 1 donors. Most W-anemic F 1 recipients were cured by parental and F 1 cell grafts (except B6 spleen). Even after 13 to 18 months, they showed little or no effect from GVH reactions. Lethally irradiated normal F 1 recipients tolerated parental marrow grafts almost as well, but gave dramatically different results with parental spleen grafts. Seventy-nine of 80 irradiated F 1 recipients of parental spleen grafts died within 1 month. Unlike lethally irradiated recipients, W-anemic recipients have substantial numbers of their own cells along with the donor cells in their lymphoid tissues. These F 1 lymphocytes may interact with parental lymphocytes in vivo to restrain reactions against F 1 allogeneic antigens

  18. Chemical memory reactions induced bursting dynamics in gene expression.

    Science.gov (United States)

    Tian, Tianhai

    2013-01-01

    Memory is a ubiquitous phenomenon in biological systems in which the present system state is not entirely determined by the current conditions but also depends on the time evolutionary path of the system. Specifically, many memorial phenomena are characterized by chemical memory reactions that may fire under particular system conditions. These conditional chemical reactions contradict to the extant stochastic approaches for modeling chemical kinetics and have increasingly posed significant challenges to mathematical modeling and computer simulation. To tackle the challenge, I proposed a novel theory consisting of the memory chemical master equations and memory stochastic simulation algorithm. A stochastic model for single-gene expression was proposed to illustrate the key function of memory reactions in inducing bursting dynamics of gene expression that has been observed in experiments recently. The importance of memory reactions has been further validated by the stochastic model of the p53-MDM2 core module. Simulations showed that memory reactions is a major mechanism for realizing both sustained oscillations of p53 protein numbers in single cells and damped oscillations over a population of cells. These successful applications of the memory modeling framework suggested that this innovative theory is an effective and powerful tool to study memory process and conditional chemical reactions in a wide range of complex biological systems.

  19. 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.

  20. 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

  1. Carbonylation as a key reaction in anaerobic acetone activation by Desulfococcus biacutus.

    Science.gov (United States)

    Gutiérrez Acosta, Olga B; Hardt, Norman; Schink, Bernhard

    2013-10-01

    Acetone is activated by aerobic and nitrate-reducing bacteria via an ATP-dependent carboxylation reaction to form acetoacetate as the first reaction product. In the activation of acetone by sulfate-reducing bacteria, acetoacetate has not been found to be an intermediate. Here, we present evidence of a carbonylation reaction as the initial step in the activation of acetone by the strictly anaerobic sulfate reducer Desulfococcus biacutus. In cell suspension experiments, CO was found to be a far better cosubstrate for acetone activation than CO2. The hypothetical reaction product, acetoacetaldehyde, is extremely reactive and could not be identified as a free intermediate. However, acetoacetaldehyde dinitrophenylhydrazone was detected by mass spectrometry in cell extract experiments as a reaction product of acetone, CO, and dinitrophenylhydrazine. In a similar assay, 2-amino-4-methylpyrimidine was formed as the product of a reaction between acetoacetaldehyde and guanidine. The reaction depended on ATP as a cosubstrate. Moreover, the specific activity of aldehyde dehydrogenase (coenzyme A [CoA] acylating) tested with the putative physiological substrate was found to be 153 ± 36 mU mg(-1) protein, and its activity was specifically induced in extracts of acetone-grown cells. Moreover, acetoacetyl-CoA was detected (by mass spectrometry) after the carbonylation reaction as the subsequent intermediate after acetoacetaldehyde was formed. These results together provide evidence that acetoacetaldehyde is an intermediate in the activation of acetone by sulfate-reducing bacteria.

  2. Beyond the hype? The response to sexual violence in the Democratic Republic of the Congo in 2011 and 2014.

    Science.gov (United States)

    Hilhorst, Dorothea; Douma, Nynke

    2018-01-01

    The Democratic Republic of the Congo (DRC) has witnessed a high prevalence of sexual violence since the wars of the mid-1990s. The huge response to it commenced around the turn of the century, but turned to 'hype' towards 2010. The paper defines 'hypes' as phenomena characterised by a media frenzy, eagerness by non-governmental organisations, and pragmatic local responses. Interviews and analyses conducted in 2011 revealed misuse of services and misrepresentation at different levels. The paper goes on to review medical and legal assistance and to provide evidence of incremental improvements in the response since 2012. It has become better coordinated, with more engagement by the DRC government, more community-oriented, and has incorporated a broader notion of gender-based violence. Nonetheless, concern remains about its impact and its continued dependence on international resources. There is apprehension too about social reactions to the problems of corruption and impunity, seemingly adding to the confusion surrounding gender relations in the country. © 2018 The Author(s). Disasters © Overseas Development Institute, 2018.

  3. [Circulating vaccine-derived poliovirus type 2 outbreak in Democratic Republic of Congo 2011-2012].

    Science.gov (United States)

    Bazira, L; Coulibaly, T; Mayenga, M; Ncharre, C; Yogolelo, R; Mbule, A; Moudzeo, H; Lwamba, P; Mulumba, A W; Cabore, J

    2015-10-01

    According to the WHO records of 2013, the incidence of poliomyelitis was reduced by more than 99%, the number of endemic countries decreased from 125 in 1988 to 3 in 2013 and over 10 million cases were prevented from poliomyelitis thanks to the intensive use of Oral polio vaccine (OPV). However, the emergence of circulating vaccine-derived poliovirus strains (cVDPV), causing serious epidemics like the wild poliovirus, is a major challenge on the final straight towards the goal of eradication and OPV cessation. This paper describes the cVDPVoutbreak that occurred in the Democratic Republic of Congo (DRC) from November 2011 to April 2012. All children under 15 years of age with acute flaccid paralysis (AFP) and confirmed presence of cVDPV in the stool samples were included. Thirty (30) children, all from the administrative territories of Bukama and Malemba Nkulu in the Katanga Province (south-east DRC), were reported. The virus responsible was the cVDPV type 2 (0.7% -3.5% divergent from the reference Sabin 2 strain) in 29 children (97%) and the ambiguous vaccine-derived poliovirus strain (0.7% divergent) was confirmed in one case (3%), a boy seventeen months old and already vaccinated four times with OPV. Twentyfive children (83%) were protected by any of the routine EPI vaccines and 3 children (10%) had never received any dose of OPV. In reaction, DRC has conducted five local campaigns over a period of 10 months (from January to October 2012) and the epidemic was stopped after the second round performed in March 2012. As elsewhere in similar conditions, low immunization coverage, poor sanitation conditions and the stop of the use of OPV2 have favoured the emergence of the third cVDPV epidemic in DRC. The implementation of the Strategic Plan for Polio eradication and endgame strategic plan 2013-2018 will prevent the emergence of cVDPV and set up the conditions for a coordinated OPV phase out.

  4. Immediate and delayed reactions to radiocontrast media: is there an allergic mechanism?

    Science.gov (United States)

    Brockow, Knut

    2009-08-01

    Radiocontrast media can cause immediate (1 hour) and nonimmediate (>1 hour) hypersensitivity reactions that remain unpredictable and a cause of concern for radiologists and cardiologists. Immediate hypersensitivity reactions resemble anaphylaxis, whereas nonimmediate ones clinically are predominated by exanthemas. Increasing evidence indicates that immediate reactions and nonimmediate skin exanthemas may be allergic reactions involving either contrast media-reactive IgE or T cells, respectively. Skin testing is a useful tool for the diagnosis of contrast media allergy. It may have an important role in the selection of a safe product in previous reactors, although validation data are still lacking. In vitro tests to search for contrast media-specific cell activation are currently under investigation.

  5. Induction of chromosomal aberrations by neutron capture reactions

    International Nuclear Information System (INIS)

    Ikushima, Takaji

    1993-01-01

    Boron neutron capture reaction (B-NCR) has been practiced in the treatment of malignancies of the central nervous system and melanoma using a thermal neutron beam from the KUR. Because of the very large neutron absorption cross-section and high kinetic energy released, gadolinium (Gd-157) has been expected to be an another promising element for neutron capture therapy. The dose-response relationship was determined for the induction of chromosomal aberrations by neutron capture reactions by B-10 and Gd-157 in cultured mammalian cells. The cells were exposed to thermal neutron beam with and without B-10 enriched (97 atom %) boric acid or Gd-DTPA, and chromosome-type aberrations were analysed in the first metaphases following irradiation. The frequency of dicentrics and rings increased linearly with neutron fluence either in the presence or absence of B-10 boric acid, while the yield of chromosomal aberrations induced by Gd-NCR increased in a linear quadratic fashion as a function of dose as in γ-rayed cells. Survival curves for the cells exposed to thermal neutrons showed no shoulder irrespective of the loading of B-10, but Gd-NCR produced the survival curve with a small shoulder. The differential chromosomal response to B-NCR and Gd-NCR might reflect the difference in radiation quality generated from the two types of thermal neutron capture reaction. (J.P.N.)

  6. Immunological aspects of nonimmediate reactions to beta-lactam antibiotics.

    Science.gov (United States)

    Rodilla, Esther Morena; González, Ignacio Dávila; Yges, Elena Laffond; Bellido, Francisco Javier Múñoz; Bara, María Teresa Gracia; Toledano, Félix Lorente

    2010-09-01

    beta-lactam antibiotics are the agents most frequently implied in immune drug adverse reactions. These can be classified as immediate or nonimmediate according to the time interval between the last drug administration and their onset. Mechanisms of immediate IgE-mediated reactions are widely studied and are therefore better understood. Nonimmediate reactions include a broad number of clinical entities like mild maculopapular exanthemas, the most common, and other less frequent but more severe reactions such as Stevens-Johnson syndrome, toxic epidermal necrolysis, acute exanthematic pustulosis or cytopenias. These nonimmediate reactions are mainly mediated by T cells but the precise underlying mechanisms are not well elucidated. This fact complicates the allergological evaluation of patients with this type of reaction and available tests have demonstrated poor sensitivity and specificity.

  7. Chemical-Reaction-Controlled Phase Separated Drops: Formation, Size Selection, and Coarsening

    Science.gov (United States)

    Wurtz, Jean David; Lee, Chiu Fan

    2018-02-01

    Phase separation under nonequilibrium conditions is exploited by biological cells to organize their cytoplasm but remains poorly understood as a physical phenomenon. Here, we study a ternary fluid model in which phase-separating molecules can be converted into soluble molecules, and vice versa, via chemical reactions. We elucidate using analytical and simulation methods how drop size, formation, and coarsening can be controlled by the chemical reaction rates, and categorize the qualitative behavior of the system into distinct regimes. Ostwald ripening arrest occurs above critical reaction rates, demonstrating that this transition belongs entirely to the nonequilibrium regime. Our model is a minimal representation of the cell cytoplasm.

  8. Human FcγRIIA induces anaphylactic and allergic reactions.

    Science.gov (United States)

    Jönsson, Friederike; Mancardi, David A; Zhao, Wei; Kita, Yoshihiro; Iannascoli, Bruno; Khun, Huot; van Rooijen, Nico; Shimizu, Takao; Schwartz, Lawrence B; Daëron, Marc; Bruhns, Pierre

    2012-03-15

    IgE and IgE receptors (FcεRI) are well-known inducers of allergy. We recently found in mice that active systemic anaphylaxis depends on IgG and IgG receptors (FcγRIIIA and FcγRIV) expressed by neutrophils, rather than on IgE and FcεRI expressed by mast cells and basophils. In humans, neutrophils, mast cells, basophils, and eosinophils do not express FcγRIIIA or FcγRIV, but FcγRIIA. We therefore investigated the possible role of FcγRIIA in allergy by generating novel FcγRIIA-transgenic mice, in which various models of allergic reactions induced by IgG could be studied. In mice, FcγRIIA was sufficient to trigger active and passive anaphylaxis, and airway inflammation in vivo. Blocking FcγRIIA in vivo abolished these reactions. We identified mast cells to be responsible for FcγRIIA-dependent passive cutaneous anaphylaxis, and monocytes/macrophages and neutrophils to be responsible for FcγRIIA-dependent passive systemic anaphylaxis. Supporting these findings, human mast cells, monocytes and neutrophils produced anaphylactogenic mediators after FcγRIIA engagement. IgG and FcγRIIA may therefore contribute to allergic and anaphylactic reactions in humans.

  9. 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

  10. Complex Chemical Reaction Networks from Heuristics-Aided Quantum Chemistry.

    Science.gov (United States)

    Rappoport, Dmitrij; Galvin, Cooper J; Zubarev, Dmitry Yu; Aspuru-Guzik, Alán

    2014-03-11

    While structures and reactivities of many small molecules can be computed efficiently and accurately using quantum chemical methods, heuristic approaches remain essential for modeling complex structures and large-scale chemical systems. Here, we present a heuristics-aided quantum chemical methodology applicable to complex chemical reaction networks such as those arising in cell metabolism and prebiotic chemistry. Chemical heuristics offer an expedient way of traversing high-dimensional reactive potential energy surfaces and are combined here with quantum chemical structure optimizations, which yield the structures and energies of the reaction intermediates and products. Application of heuristics-aided quantum chemical methodology to the formose reaction reproduces the experimentally observed reaction products, major reaction pathways, and autocatalytic cycles.

  11. Chemical Principles Revisited. Redox Reactions and the Electropotential Axis.

    Science.gov (United States)

    Vella, Alfred J.

    1990-01-01

    This paper suggests a nontraditional pedagogic approach to the subject of redox reactions and electrode potentials suitable for freshman chemistry. Presented is a method for the representation of galvanic cells without the introduction of the symbology and notation of conventional cell diagrams. (CW)

  12. 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.

  13. An Advanced Dictionary? Similarities and Differences between Duramazwi ReChiShona and Duramazwi Guru ReChiShona *

    Directory of Open Access Journals (Sweden)

    Emmanuel Chabata

    2011-10-01

    Full Text Available

    Abstract: In this article a comparative analysis of Duramazwi ReChiShona (DRC and Duramazwi Guru ReChiShona (DGC is made. Both DRC and DGC are monolingual Shona dictionaries compiled by a team of researchers under the African Languages Lexical (ALLEX Project, now the African Languages Research Institute (ALRI. During the compilation process, DRC was known as the General Shona Dictionary and DGC as the Advanced Shona Dictionary. A simple analysis of these titles shows that the dictionaries are similar in some ways and also different in others. The writer tries to show the ways in which DGC is regarded as a more advanced dictionary when compared to DRC. Although the argument of the article is mainly built on those differences which make DGC the more advanced, attention is also paid to the similarities between the dictionaries.

    Keywords: ALLEX PROJECT, ALRI, DURAMAZWI RECHISHONA, DURAMAZWI GURU RECHISHONA, DICTIONARY, SHONA, HEADWORD, SENSE, MONOLINGUAL DICTIONARY, CORPUS, IDIOM, PROVERB, PITHY SAYING

    Opsomming: 'n Gevorderde woordeboek? Ooreenkomste en verskille tussen Duramazwi ReChiShona en Duramazwi Guru ReChiShona. In hierdie artikel word 'n vergelykende ontleding van Duramazwi ReChiShona (DRC en Duramazwi Guru ReChiShona (DGC gemaak. Sowel die DRC en DGC is eentalige Sjonawoordeboeke, saamgestel deur ?n span navorsers by die African Languages Lexical (ALLEX Project, tans die African Languages Research Institute (ALRI. Gedurende die samestellingsproses was DRC bekend as die Algemene Sjonawoordeboek en DGC as die Gevorderde Sjonawoordeboek. 'n Eenvoudige ontleding van hierdie titels toon dat die woordeboeke op sommige maniere eenders en op ander ook verskillend is. Die skrywer probeer die maniere aantoon waarop DGC beskou word as 'n meer gevorderde woordeboek wanneer dit met DRC vergelyk word. Alhoewel die argument van die artikel hoofsaaklik gebou is op daardie verskille wat DGC die gevorderdste maak, word ook aandag gegee aan

  14. Reaction chemistry in rechargeable Li-O2 batteries.

    Science.gov (United States)

    Lim, Hee-Dae; Lee, Byungju; Bae, Youngjoon; Park, Hyeokjun; Ko, Youngmin; Kim, Haegyeom; Kim, Jinsoo; Kang, Kisuk

    2017-05-22

    The seemingly simple reaction of Li-O 2 batteries involving lithium and oxygen makes this chemistry attractive for high-energy-density storage systems; however, achieving this reaction in practical rechargeable Li-O 2 batteries has proven difficult. The reaction paths leading to the final Li 2 O 2 discharge products can be greatly affected by the operating conditions or environment, which often results in major side reactions. Recent research findings have begun to reveal how the reaction paths may be affected by the surrounding conditions and to uncover the factors contributing to the difficulty in achieving the reactions of lithium and oxygen. This progress report describes the current state of understanding of the electrode reaction mechanisms in Li-O 2 batteries; the factors that affect reaction pathways; and the effect of cell components such as solvents, salts, additives, and catalysts on the discharge product and its decomposition during charging. This comprehensive review of the recent progress in understanding the reaction chemistry of the Li-O 2 system will serve as guidelines for future research and aid in the development of reliable high-energy-density rechargeable Li-O 2 batteries.

  15. FEMA Disaster Recovery Centers

    Data.gov (United States)

    Department of Homeland Security — This is a search site for FEMA's Disaster Recovery Centers (DRC). A DRC is a readily accessible facility or mobile office set up by FEMA where applicants may go for...

  16. FEMA Disaster Recovery Centers - KML

    Data.gov (United States)

    Department of Homeland Security — This is a KML file for FEMA's Disaster Recovery Centers (DRC). A DRC is a readily accessible facility or mobile office set up by FEMA where applicants may go for...

  17. Tc1-mediated contact sensitivity reaction, its mechanism and regulation

    Directory of Open Access Journals (Sweden)

    Magdalena Zemelka-Wiącek

    2014-07-01

    Full Text Available The contact hypersensitivity reaction (CHS to haptens is a classic example of cell-mediated immune response. In the effector phase, two stages can be distinguished: an early component, that appears only 2 hours after subsequent contact with the hapten, and the late component that develops approximately 24 hours later which is mediated by TCRαβ+ cells. The effector lymphocytes may be CD4+ T helper 1 (Th1 cells or CD8+ T cytotoxic 1 (Tc1 cells, which depends on the employed hapten and/or mice strain. NKT lymphocytes play the crucial role in the CHS initiation, by supporting B1 cells in the antigen-specific IgM antibodies production. The development of an early component is essential for the recruitment of T effector (Teff cells to the side of hapten deposition and for the complete expansion of inflammatory reaction. The CHS reaction is under T regulatory (Treg cells control, both in the induction phase as well as in the effector phase. A new view of a negative regulation of the Tc1 mediated CHS response is based on the suppression induced by epicutaneous (EC application of protein antigen. The DNP-BSA skin application, on a gauze patch, leads to a state of immunosuppression. This maneuver results in rising the population of Treg cells with TCRαβ+CD4+CD25+Foxp3+ phenotype. The mechanism of suppression requires direct contact between Treg cells and Teff cells and the participation of CTLA-4 molecule is also necessary. The described method of evoking immune tolerance via EC immunization may contribute to elaborate a new method of allergic contact dermatitis therapy. This is because of its effectiveness, ease of induction and non-invasive protein antigen application.

  18. Experimental study o the sodium-concrete reaction

    International Nuclear Information System (INIS)

    Goncalves, A.C.; Torres, A.R.; Brito Aghina, L.O. de; Messere e Castro, P.

    1986-01-01

    Effects and aspects of security are verified during a sodium leakage in high temperatures on liners of contention cells and directly on the concrete. As this kinetic process involves reactions between materials in solid state (such as oxides and carbonates) vapors and gases (such as water and CO 2 )) with liquid sodium, effects of each phase of the heterogeneous mixture are separately analysed. Are still analysed produced products and briefly discussed the kinetic of the sodium-concrete reaction. (Author) [pt

  19. Transfusion reactions in pediatric compared with adult patients: a look at rate, reaction type, and associated products.

    Science.gov (United States)

    Oakley, Fredrick D; Woods, Marcella; Arnold, Shanna; Young, Pampee P

    2015-03-01

    The majority of reports on transfusion reactions address adult patients. Less is known about the types, incidence, and other clinical details of transfusion reactions in pediatric populations. Furthermore, to our knowledge, there have been no previous reports directly comparing these aspects between adults and pediatric patient populations to assess if there are differences. Between the period of January 1, 2011, and February 1, 2013, all reported adult and pediatric transfusion reactions at Vanderbilt University Medical Center (VUMC) were evaluated by transfusion medicine clinical service. The information was subsequently shared with the hemovigilance database. Data provided to hemovigilance included age, sex, blood product associated with the reaction, severity of the reaction, and the type of transfusion reactions. These were collated with hospital and blood bank information system-acquired data on overall admission and product transfusion. A total of 133,671 transfusions were performed at VUMC during the study period including 20,179 platelet (PLT) transfusions, 31,605 plasma transfusions, 79,933 red blood cell (RBC) transfusions, and 2154 cryoprecipitate transfusions. Over the same period, 108 pediatric and 277 adult transfusion reactions were recorded. This corresponds to an incidence of 6.2 reactions per 1000 transfusions within the pediatric (age reactions per 1000 transfusions within the adult population. In both adult and pediatric populations, transfusion reactions were most commonly associated with PLT, followed by RBC, and then plasma transfusions. Within the pediatric population, subset analysis identified multiple differences when compared to the adult population, including an increased incidence of allergic transfusion reactions (2.7/1000 vs. 1.1/1000, p reactions (1.9/1000 vs. 0.47/1000, p reactions (0.29/1000 vs. 0.078/1000, p reaction incidence was the same between sexes in adults, in pediatric patients, reactions were more common in male

  20. 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.

  1. 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.

  2. 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.

  3. Molecular controls of the oxygenation and redox reactions of hemoglobin.

    Science.gov (United States)

    Bonaventura, Celia; Henkens, Robert; Alayash, Abdu I; Banerjee, Sambuddha; Crumbliss, Alvin L

    2013-06-10

    The broad classes of O(2)-binding proteins known as hemoglobins (Hbs) carry out oxygenation and redox functions that allow organisms with significantly different physiological demands to exist in a wide range of environments. This is aided by allosteric controls that modulate the protein's redox reactions as well as its O(2)-binding functions. The controls of Hb's redox reactions can differ appreciably from the molecular controls for Hb oxygenation and come into play in elegant mechanisms for dealing with nitrosative stress, in the malarial resistance conferred by sickle cell Hb, and in the as-yet unsuccessful designs for safe and effective blood substitutes. An important basic principle in consideration of Hb's redox reactions is the distinction between kinetic and thermodynamic reaction control. Clarification of these modes of control is critical to gaining an increased understanding of Hb-mediated oxidative processes and oxidative toxicity in vivo. This review addresses emerging concepts and some unresolved questions regarding the interplay between the oxygenation and oxidation reactions of structurally diverse Hbs, both within red blood cells and under acellular conditions. Developing methods that control Hb-mediated oxidative toxicity will be critical to the future development of Hb-based blood substitutes.

  4. National-scale estimation of gross forest aboveground carbon loss: a case study of the Democratic Republic of the Congo

    International Nuclear Information System (INIS)

    Tyukavina, A; Potapov, P V; Turubanova, S A; Hansen, M C; Stehman, S V; Baccini, A; Goetz, S J; Laporte, N T; Houghton, R A

    2013-01-01

    Recent advances in remote sensing enable the mapping and monitoring of carbon stocks without relying on extensive in situ measurements. The Democratic Republic of the Congo (DRC) is among the countries where national forest inventories (NFI) are either non-existent or out of date. Here we demonstrate a method for estimating national-scale gross forest aboveground carbon (AGC) loss and associated uncertainties using remotely sensed-derived forest cover loss and biomass carbon density data. Lidar data were used as a surrogate for NFI plot measurements to estimate carbon stocks and AGC loss based on forest type and activity data derived using time-series multispectral imagery. Specifically, DRC forest type and loss from the FACET (Forêts d’Afrique Centrale Evaluées par Télédétection) product, created using Landsat data, were related to carbon data derived from the Geoscience Laser Altimeter System (GLAS). Validation data for FACET forest area loss were created at a 30-m spatial resolution and compared to the 60-m spatial resolution FACET map. We produced two gross AGC loss estimates for the DRC for the last decade (2000–2010): a map-scale estimate (53.3 ± 9.8 Tg C yr −1 ) accounting for whole-pixel classification errors in the 60-m resolution FACET forest cover change product, and a sub-grid estimate (72.1 ± 12.7 Tg C yr −1 ) that took into account 60-m cells that experienced partial forest loss. Our sub-grid forest cover and AGC loss estimates, which included smaller-scale forest disturbances, exceed published assessments. Results raise the issue of scale in forest cover change mapping and validation, and subsequent impacts on remotely sensed carbon stock change estimation, particularly for smallholder dominated systems such as the DRC. (letter)

  5. 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

  6. Antiretroviral treatment program retention among HIV-infected children in the Democratic Republic of Congo.

    Directory of Open Access Journals (Sweden)

    John Ditekemena

    Full Text Available BACKGROUND: Retaining patients with HIV infection in care is still a major challenge in sub- Saharan Africa, particularly in the Democratic Republic of Congo (DRC where the antiretroviral treatment (ART coverage is low. Monitoring retention is an important tool for evaluating the quality of care. METHODS AND FINDINGS: A review of medical records of HIV-infected children was performed in three health facilities in the DRC: the Amo-Congo Health center, the Monkole Clinic in Kinshasa, and the HEAL Africa Clinic in Goma. Medical records of 720 children were included. Kaplan Meier curves were constructed with the probability of retention at 6 months, 1 year, 2 years and 3 years. Retention rates were: 88.2% (95% CI: 85.1%-90.8% at 6 months; 85% (95% CI: 81.5%-87.6% at one year; 79.4% (95%CI: 75.5%-82.8% at two years and 74.7% (95% CI: 70.5%-78.5% at 3 years. The retention varied across study sites: 88.2%, 66.6% and 92.5% at 6 months; 84%, 59% and 90% at 12 months and 75.7%, 56.3% and 85.8% at 24 months respectively for Amo-Congo/Kasavubu, Monkole facility and HEAL Africa. After multivariable Cox regression four variables remained independently associated with attrition: study site, CD4 cell count <350 cells/µL, children younger than 2 years and children whose caregivers were member of an independent church. CONCLUSIONS: Attrition remains a challenge for pediatric HIV positive patients in ART programs in DRC. In addition, the low coverage of pediatric treatment exacerbates the situation of pediatric HIV/AIDS.

  7. 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.

  8. Inter-individual variation in nucleotide excision repair pathway is modulated by non-synonymous polymorphisms in ERCC4 and MBD4 genes

    Energy Technology Data Exchange (ETDEWEB)

    Allione, Alessandra, E-mail: alessandra.allione@hugef-torino.org [Human Genetics Foundation (HuGeF), Via Nizza 52, 10126 Turin (Italy); Guarrera, Simonetta; Russo, Alessia [Human Genetics Foundation (HuGeF), Via Nizza 52, 10126 Turin (Italy); Ricceri, Fulvio [Human Genetics Foundation (HuGeF), Via Nizza 52, 10126 Turin (Italy); Department of Medical Sciences, University of Turin, Via Santena 19, 10126 Turin (Italy); Purohit, Rituraj [Human Genetics Foundation (HuGeF), Via Nizza 52, 10126 Turin (Italy); Bioinformatics Division, School of Bio Sciences and Technology, Vellore Institute of Technology University, Vellore 632014, Tamil Nadu (India); Pagnani, Andrea; Rosa, Fabio; Polidoro, Silvia; Voglino, Floriana [Human Genetics Foundation (HuGeF), Via Nizza 52, 10126 Turin (Italy); Matullo, Giuseppe [Human Genetics Foundation (HuGeF), Via Nizza 52, 10126 Turin (Italy); Department of Medical Sciences, University of Turin, Via Santena 19, 10126 Turin (Italy)

    2013-11-15

    Highlights: • We reported a large inter-individual variability of NER capacity. • ERCC4 rs1800124 and MBD4 rs10342 nsSNP variants were associated with DNA repair capacity. • DNA–protein interaction analyses showed alteration of binding for ERCC4 and MBD4 variants. • A new possible cross-talk between NER and BER pathways has been reported. - Abstract: Inter-individual differences in DNA repair capacity (DRC) may lead to genome instability and, consequently, modulate individual cancer risk. Among the different DNA repair pathways, nucleotide excision repair (NER) is one of the most versatile, as it can eliminate a wide range of helix-distorting DNA lesions caused by ultraviolet light irradiation and chemical mutagens. We performed a genotype–phenotype correlation study in 122 healthy subjects in order to assess if any associations exist between phenotypic profiles of NER and DNA repair gene single nucleotide polymorphisms (SNPs). Individuals were genotyped for 768 SNPs with a custom Illumina Golden Gate Assay, and peripheral blood mononuclear cells (PBMCs) of the same subjects were tested for a NER comet assay to measure DRC after challenging cells by benzo(a)pyrene diolepoxide (BPDE). We observed a large inter-individual variability of NER capacity, with women showing a statistically significant lower DRC (mean ± SD: 6.68 ± 4.76; p = 0.004) than men (mean ± SD: 8.89 ± 5.20). Moreover, DRC was significantly lower in individuals carrying a variant allele for the ERCC4 rs1800124 non-synonymous SNP (nsSNP) (p = 0.006) and significantly higher in subjects with the variant allele of MBD4 rs2005618 SNP (p = 0.008), in linkage disequilibrium (r{sup 2} = 0.908) with rs10342 nsSNP. Traditional in silico docking approaches on protein–DNA and protein–protein interaction showed that Gly875 variant in ERCC4 (rs1800124) decreases the DNA–protein interaction and that Ser273 and Thr273 variants in MBD4 (rs10342) indicate complete loss of protein

  9. 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.

  10. Analysis of army-wide hearing conservation database for hearing profiles related to crew-served and individual weapon systems

    Directory of Open Access Journals (Sweden)

    William A Ahroon

    2011-01-01

    Full Text Available Damage-risk criteria (DRC for noise exposures are designed to protect 95% of the exposed populations from hearing injuries caused by those noise exposures. The current DRC used by the US military follows OSHA guidelines for continuous noise. The current military DRC for impulse exposures follows the recommendations from the National Academy of Sciences - National Research Council Committee on Hearing, Bioacoustics, and Biomechanics (CHABA and are contained in the current military standard, MIL-STD-1474D "Noise Limits." Suggesting that the MIL-STD for impulse exposure is too stringent, various individuals have proposed that the DRC for exposure to high-level impulses be relaxed. The purpose of this study is to evaluate the current hearing status of US Army Soldiers, some of whom can be, by their military occupational specialties (MOS, reasonably expected to be routinely exposed to high-level impulses from weapon systems. The Defense Occupational and Environmental Health Readiness System - Hearing Conservation (DOEHRS-HC was queried for the hearing status of enlisted Soldiers of 32 different MOSs. The results indicated that less than 95% of the Soldiers in the DOEHRS-HC database were classified as having normal hearing. In other words, the goal of the DRC used for limiting noise injuries (from continuous and impulse exposures was not stringent enough to prevent hearing injuries in all but the most susceptible Soldiers. These results suggest that the current military noise DRC should not be relaxed.

  11. 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

  12. Ecologic Features of Plague Outbreak Areas, Democratic Republic of the Congo, 2004–2014

    Science.gov (United States)

    Shako, Jean-Christophe; Gaudart, Jean; Sudre, Bertrand; Ilunga, Benoit Kebela; Shamamba, Stomy Karhemere Bi; Diatta, Georges; Davoust, Bernard; Tamfum, Jean-Jacques Muyembe; Piarroux, Renaud; Piarroux, Martine

    2018-01-01

    During 2004–2014, the Democratic Republic of the Congo (DRC) declared 54% of plague cases worldwide. Using national data, we characterized the epidemiology of human plague in DRC for this period. All 4,630 suspected human plague cases and 349 deaths recorded in DRC came from Orientale Province. Pneumonic plague cases (8.8% of total) occurred during 2 major outbreaks in mining camps in the equatorial forest, and some limited outbreaks occurred in the Ituri highlands. Epidemics originated in 5 health zones clustered in Ituri, where sporadic bubonic cases were recorded throughout every year. Classification and regression tree characterized this cluster by the dominance of ecosystem 40 (mountain tropical climate). In conclusion, a small, stable, endemic focus of plague in the highlands of the Ituri tropical region persisted, acting as a source of outbreaks in DRC. PMID:29350136

  13. Auditory-model based assessment of the effects of hearing loss and hearing-aid compression on spectral and temporal resolution

    DEFF Research Database (Denmark)

    Kowalewski, Borys; MacDonald, Ewen; Strelcyk, Olaf

    2016-01-01

    . However, due to the complexity of speech and its robustness to spectral and temporal alterations, the effects of DRC on speech perception have been mixed and controversial. The goal of the present study was to obtain a clearer understanding of the interplay between hearing loss and DRC by means......Most state-of-the-art hearing aids apply multi-channel dynamic-range compression (DRC). Such designs have the potential to emulate, at least to some degree, the processing that takes place in the healthy auditory system. One way to assess hearing-aid performance is to measure speech intelligibility....... Outcomes were simulated using the auditory processing model of Jepsen et al. (2008) with the front end modified to include effects of hearing impairment and DRC. The results were compared to experimental data from normal-hearing and hearing-impaired listeners....

  14. 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

  15. 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.

  16. Liver investigation with respect to possible reactions to radiotherapy

    International Nuclear Information System (INIS)

    Wolzenburg, G.

    1980-01-01

    A partial liver irradiation was performed in 98 patients within the framework of an Y-field- or kidney-bed-after-irradiation. The liver reaction was tested by means of scintigraphy. In 73 patients, i.e. 74.5 percent of all cases, no increase in the storage capacity of the Kupffer-cells could be found as a consequence of the radiotherapy. In 16 of the patients (16.3 percent) a focused limited band-like necess could be found that corresponded to the irradiation field. The rest of the activity distribution was standard. In 9 of the patients pathological liver processes were independent of the therapy. The values of the lencocytes and thrombocytes were examined during and after the radiation therapy for similarities in 16 patients with liver reactions against irradiation. The values were compared with the course in patients without irradiation reaction. A correlation between blood-level processes and irradiation reactions of the Kupffer star-cells could not be determined. The liver function of RES appeared limited already by 3000 rads within 3 weeks after the end of the treatment. A complete restitution appeared within 18 months - even without the attempt of a treatment. (orig.) [de

  17. 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...

  18. 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.

  19. Direct interaction in nuclear reactions: a theory; L'interaction directe dans les reactions nucleaires: theorie

    Energy Technology Data Exchange (ETDEWEB)

    Dominicis, C.T. de [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    General treatment of the foundations of direct interaction in nuclear reactions; representation of the instantaneous elastic scattering amplitude by the scattering amplitude due to a complex potential; expansion of the instantaneous inelastic scattering amplitude and discussion of the 1. Bohr approximation (distorted waves) contribution to individual and collective states of excitation. (author) [French] Expose general sur les fondements de l'interaction directe dans les reactions nucleaires; representation de l'amplitude de diffusion instantanee elastique par celle due a un potentiel complexe; developpement de l'amplitude de diffusion instantanee inelastique et discussion de la contribution de la premiere approximation de Bohr (sur des distendues) a l'excitation d'etats individuels et collectifs. (auteur)

  20. Late adverse reactions to intravascular iodinated contrast media

    International Nuclear Information System (INIS)

    Webb, Judith A.W.; Stacul, Fulvio; Thomsen, Henrik S.; Morcos, Sameh K.

    2003-01-01

    Late adverse reactions to intravascular iodinated contrast media are defined as reactions occurring 1 h to 1 week after contrast medium injection. They have received increasing interest over the past decade, but their prevalence remains uncertain and their pathophysiology is not fully understood. The Contrast Media Safety Committee of the European Society of Urogenital Radiology decided to review the literature and to issue guidelines. An extensive literature search was carried out and summarized in a report. Based on the available information, simple guidelines have been drawn up. The report and guidelines were discussed at the 8th European Symposium on Urogenital Radiology in Genoa. Late adverse reactions after intravascular iodinated contrast medium include symptoms such as nausea, vomiting, headache, itching, skin rash, musculoskeletal pain, and fever. A significant proportion of these reactions is unrelated to the contrast medium; however, allergy-like skin reactions are well-documented side effects of contrast media with an incidence of approximately 2%. Late reactions appear to be commoner after non-ionic dimers. The majority of late skin reactions after contrast medium exposure are probably T-cell-mediated allergic reactions. Patients at increased risk of late skin reactions are those with a history of previous contrast medium reaction and those on interleukin-2 treatment. Most skin reactions are self-limiting and resolve within a week. Management is symptomatic and similar to the management of other drug-induced skin reactions. (orig.)

  1. 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.

  2. Electrodeposition of Pd based binary catalysts on Carbon paper via surface limited redox-replacement reaction for oxygen reduction reaction

    CSIR Research Space (South Africa)

    Modibedi, RM

    2014-05-01

    Full Text Available Direct alcohol fuel cells (DAFCs) continue to extensive attention as potential power sources for portable and stationary applications. The oxygen reduction reaction (ORR) involving the four electron transfer remains a challenge for DAFCs due to its...

  3. Remodelling of cellular excitation (reaction) and intercellular coupling (diffusion) by chronic atrial fibrillation represented by a reaction-diffusion system

    Science.gov (United States)

    Zhang, Henggui; Garratt, Clifford J.; Kharche, Sanjay; Holden, Arun V.

    2009-06-01

    Human atrial tissue is an excitable system, in which myocytes are excitable elements, and cell-to-cell electrotonic interactions are via diffusive interactions of cell membrane potentials. We developed a family of excitable system models for human atrium at cellular, tissue and anatomical levels for both normal and chronic atrial fibrillation (AF) conditions. The effects of AF-induced remodelling of cell membrane ionic channels (reaction kinetics) and intercellular gap junctional coupling (diffusion) on atrial excitability, conduction of excitation waves and dynamics of re-entrant excitation waves are quantified. Both ionic channel and gap junctional coupling remodelling have rate dependent effects on atrial propagation. Membrane channel conductance remodelling allows the propagation of activity at higher rates than those sustained in normal tissue or in tissue with gap junctional remodelling alone. Membrane channel conductance remodelling is essential for the propagation of activity at rates higher than 300/min as seen in AF. Spatially heterogeneous gap junction coupling remodelling increased the risk of conduction block, an essential factor for the genesis of re-entry. In 2D and 3D anatomical models, the dynamical behaviours of re-entrant excitation waves are also altered by membrane channel modelling. This study provides insights to understand the pro-arrhythmic effects of AF-induced reaction and diffusion remodelling in atrial tissue.

  4. PhreeqcRM: A reaction module for transport simulators based on the geochemical model PHREEQC

    Science.gov (United States)

    Parkhurst, David L.; Wissmeier, Laurin

    2015-01-01

    PhreeqcRM is a geochemical reaction module designed specifically to perform equilibrium and kinetic reaction calculations for reactive transport simulators that use an operator-splitting approach. The basic function of the reaction module is to take component concentrations from the model cells of the transport simulator, run geochemical reactions, and return updated component concentrations to the transport simulator. If multicomponent diffusion is modeled (e.g., Nernst–Planck equation), then aqueous species concentrations can be used instead of component concentrations. The reaction capabilities are a complete implementation of the reaction capabilities of PHREEQC. In each cell, the reaction module maintains the composition of all of the reactants, which may include minerals, exchangers, surface complexers, gas phases, solid solutions, and user-defined kinetic reactants.PhreeqcRM assigns initial and boundary conditions for model cells based on standard PHREEQC input definitions (files or strings) of chemical compositions of solutions and reactants. Additional PhreeqcRM capabilities include methods to eliminate reaction calculations for inactive parts of a model domain, transfer concentrations and other model properties, and retrieve selected results. The module demonstrates good scalability for parallel processing by using multiprocessing with MPI (message passing interface) on distributed memory systems, and limited scalability using multithreading with OpenMP on shared memory systems. PhreeqcRM is written in C++, but interfaces allow methods to be called from C or Fortran. By using the PhreeqcRM reaction module, an existing multicomponent transport simulator can be extended to simulate a wide range of geochemical reactions. Results of the implementation of PhreeqcRM as the reaction engine for transport simulators PHAST and FEFLOW are shown by using an analytical solution and the reactive transport benchmark of MoMaS.

  5. 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.

  6. Radiation induced cell death in cervical squamous cell carcinoma. An immunohistochemical and ultrastructural study

    International Nuclear Information System (INIS)

    Atari, Eio; Toda, Takayoshi; Sadi, A.M.; Egawa, Haruhiko; Moromizato, Hidehiko; Mamadi, T.; Kiyuna, Masaya

    1998-01-01

    To study the process of cell death in cervical squamous cell carcinoma (SCC) after radiation, an ultrastructural and immunohistochemical study was performed. Paraffin-embedded tissue blocks of biopsy samples pre- and post-radiation stage III SCC (n=15) were collected. Irradiation caused varying ultrastructural changes including nuclear and cytoplasmic disorganization suggesting cell necrosis. Immunohistochemically, the pre-radiation specimens showed no positive reaction for tumor necrosis factor-alpha (TNF-α), tumor necrosis factor-receptor (TNF-γ) or Fas. C-fos, p53 and bcl-2 showed positive reactions in only a few non-irradiated specimens. All of the irradiated specimens showed a positive reaction for TNF-α, and variable positive reactions were observed for TNF-γ, Fas, p53, c-fos and bcl-2. These results suggest that TNF-α, TNF-γ, and c-fos are responsible for radiation induced cell death in cervical SCC. (author)

  7. Molecular Controls of the Oxygenation and Redox Reactions of Hemoglobin

    Science.gov (United States)

    Henkens, Robert; Alayash, Abdu I.; Banerjee, Sambuddha; Crumbliss, Alvin L.

    2013-01-01

    Abstract Significance: The broad classes of O2-binding proteins known as hemoglobins (Hbs) carry out oxygenation and redox functions that allow organisms with significantly different physiological demands to exist in a wide range of environments. This is aided by allosteric controls that modulate the protein's redox reactions as well as its O2-binding functions. Recent Advances: The controls of Hb's redox reactions can differ appreciably from the molecular controls for Hb oxygenation and come into play in elegant mechanisms for dealing with nitrosative stress, in the malarial resistance conferred by sickle cell Hb, and in the as-yet unsuccessful designs for safe and effective blood substitutes. Critical Issues: An important basic principle in consideration of Hb's redox reactions is the distinction between kinetic and thermodynamic reaction control. Clarification of these modes of control is critical to gaining an increased understanding of Hb-mediated oxidative processes and oxidative toxicity in vivo. Future Directions: This review addresses emerging concepts and some unresolved questions regarding the interplay between the oxygenation and oxidation reactions of structurally diverse Hbs, both within red blood cells and under acellular conditions. Developing methods that control Hb-mediated oxidative toxicity will be critical to the future development of Hb-based blood substitutes. Antioxid. Redox Signal. 18, 2298–2313. PMID:23198874

  8. Toxicological analysis of limonene reaction products using an in vitro exposure system

    Science.gov (United States)

    Anderson, Stacey E.; Khurshid, Shahana S.; Meade, B. Jean; Lukomska, Ewa; Wells, J.R.

    2015-01-01

    Epidemiological investigations suggest a link between exposure to indoor air chemicals and adverse health effects. Consumer products contain reactive chemicals which can form secondary pollutants which may contribute to these effects. The reaction of limonene and ozone is a well characterized example of this type of indoor air chemistry. The studies described here characterize an in vitro model using an epithelial cell line (A549) or differentiated epithelial tissue (MucilAir™). The model is used to investigate adverse effects following exposure to combinations of limonene and ozone. In A549 cells, exposure to both the parent compounds and reaction products resulted in alterations in inflammatory cytokine production. A one hour exposure to limonene + ozone resulted in decreased proliferation when compared to cells exposed to limonene alone. Repeated dose exposures of limonene or limonene + ozone were conducted on MucilAir™ tissue. No change in proliferation was observed but increases in cytokine production were observed for both the parent compounds and reaction products. Factors such as exposure duration, chemical concentration, and sampling time point were identified to influence result outcome. These findings suggest that exposure to reaction products may produce more severe effects compared to the parent compound. PMID:23220291

  9. 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.

  10. LSM-YSZ Cathodes with Reaction-Infiltrated Nanoparticles

    International Nuclear Information System (INIS)

    Lu, Chun; Sholklapper, Tal Z.; Jacobson, Craig P.; Visco, StevenJ.; De Jonghe, Lutgard C.

    2006-01-01

    To improve the LSM-YSZ cathode performance of intermediate temperature solid oxide fuel cells (SOFCs), Sm0.6Sr0.4CoO3-sigma (SSC) perovskite nanoparticles are incorporated into the cathodes by a reaction-infiltration process. The SSC particles are ∼20 to 80nm in diameter, and intimately adhere to the pore walls of the preformed LSM-YSZ cathodes. The SSC particles dramatically enhance single-cell performance with a 97 percent H2+3 percent H2O fuel, between 600 C and 800 C. Consideration of a simplified TPB (triple phase boundary) reaction geometry indicates that the enhancement may be attributed to the high electrocatalytic activity of SSC for electrochemical reduction of oxygen in a region that can be located a small distance away from the strict triple phase boundaries. The implication of this work for developing high-performance electrodes is also discussed

  11. 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

  12. Dream-reality confusion in Borderline Personality Disorder: A theoretical analysis

    Directory of Open Access Journals (Sweden)

    Dagna eSkrzypińska

    2015-09-01

    Full Text Available This paper presents an analysis of dream-reality confusion (DRC in relation to the characteristics of borderline personality disorder (BPD, based on research findings and theoretical considerations. It is hypothesized that people with BPD are more likely to experience DRC compared to people in non-clinical population. Several variables related to this hypothesis were identified through a theoretical analysis of the scientific literature. Sleep disturbances: Problems with sleep are found in 15-95.5% of people with BPD (Hafizi, 2013, and unstable sleep and wake cycles, which occur in BPD (Fleischer et al., 2012, are linked to DRC. Dissociation: Nearly two-thirds of people with BPD experience dissociative symptoms (Korzekwa and Pain, 2009 and dissociative symptoms are correlated with a fantasy proneness; both dissociative symptoms and fantasy proneness are related to DRC (Giesbrecht and Merckelbach, 2006. Negative dream content: People with BPD have nightmares more often than other people (Semiz et al., 2008; dreams that are more likely to be confused with reality tend to be more realistic and unpleasant, and are reflected in waking behavior (Rassin et al., 2001. Cognitive disturbances: Many BPD patients experience various cognitive disturbances, including problems with reality testing (Fiqueierdo, 2006; Mosquera et al., 2011, which can foster DRC. Thin boundaries: People with thin boundaries are more prone to DRC than people with thick boundaries, and people with BPD tend to have thin boundaries (Hartmann, 2011. The theoretical analysis on the basis of these findings suggests that people who suffer from BPD may be more susceptible to confusing dream content with actual waking events.

  13. Dexamethasone, rituximab and cyclophosphamide for relapsed and/or refractory and treatment-naïve patients with Waldenstrom macroglobulinemia.

    Science.gov (United States)

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

    2017-10-01

    The management of Waldenström macroglobulinaemia (WM) relies predominantly on small trials, one of which has demonstrated activity of dexamethasone, rituximab and cyclophosphamide (DRC) in the frontline setting. We report on the efficacy of DRC, focusing on relapsed/refractory (R/R) patients. Ibrutinib, a recently approved agent in WM demonstrated limited activity in patients with MYD88 WT genotype. Herein, we additionally report on the activity of DRC based on the MYD88 L265P mutation status. Of 100 WM patients evaluated between January 2007 and December 2014 who received DRC, 50 had R/R WM. The overall response rate (ORR) was 87%. The median progression-free survival (PFS) and time-to-next-therapy (TTNT) were 32 (95% confidence interval [CI]: 15-51) and 50 (95% CI: 35-60) months, respectively. In the previously untreated cohort (n = 50), the ORR was 96%, and the median PFS and TTNT were 34 months (95% CI: 23-not reached [NR]) and NR (95% CI: 37-NR), respectively. Twenty-five (86%) of 29 genotyped patients harbored MYD88 L265P . The response rates and outcomes were independent of MYD88 mutation status. Grade ≥3 adverse effects included neutropenia (20%), thrombocytopenia (7%) and infections (3%). Similar to the frontline setting, DRC is an effective and well-tolerated salvage regimen for WM. In contrast to ibrutinib, DRC offers a less expensive, fixed-duration option, with preliminary data suggesting efficacy independent of the patients' MYD88 status. © 2017 John Wiley & Sons Ltd.

  14. Prospective validation of an automated chemiluminescence-based assay of renin and aldosterone for the work-up of arterial hypertension.

    Science.gov (United States)

    Rossi, Gian Paolo; Ceolotto, Giulio; Rossitto, Giacomo; Seccia, Teresa Maria; Maiolino, Giuseppe; Berton, Chiara; Basso, Daniela; Plebani, Mario

    2016-09-01

    The availability of simple and accurate assays of plasma active renin (DRC) and aldosterone concentration (PAC) can improve the detection of secondary forms of arterial hypertension. Thus, we investigated the performance of an automated chemiluminescent assay for DRC and PAC in referred hypertensive patients. We prospectively recruited 260 consecutive hypertensive patients referred to an ESH Center for Hypertension. After exclusion of six protocol violations, 254 patients were analyzed: 67.3% had primary hypertension, 17.3% an aldosterone producing adenoma (APA), 11.4% idiopathic hyperaldosteronism (IHA), 2.4% renovascular hypertension (RVH), 0.8% familial hyperaldosteronism type 1 (FH-1), 0.4% apparent mineralocorticoid excess (AME), 0.4% a renin-producing tumor, and 3.9% were adrenalectomized APA patients. Bland-Altman plots and Deming regression were used to analyze results. The diagnostic accuracy (area under the curve, AUC of the ROC) of the DRC-based aldosterone-renin ratio (ARRCL) was compared with that of the PRA-based ARR (ARRRIA) using as reference the conclusive diagnosis of APA. At Bland-Altman plot, the DRC and PAC assay showed no bias as compared to the PRA and PAC assay. A tight relation was found between the DRC and the PRA values (concordance correlation coefficient=0.92, pAPA identification the AUC of the ARRCL was higher than that of the ARRRIA [0.974 (95% CI 0.940-0.991) vs. 0.894 (95% CI 0.841-0.933), p=0.02]. This rapid automated chemiluminescent DRC/PAC assay performed better than validated PRA/PAC radioimmunoassays for the identification of APA in referred hypertensive patients.

  15. Anti-regulatory T cells

    DEFF Research Database (Denmark)

    Andersen, Mads Hald

    2017-01-01

    responses to tumours or inhibiting autoimmunity development. However, recent studies report the discovery of self-reactive pro-inflammatory T cells—termed anti-regulatory T cells (anti-Tregs)—that target immune-suppressive cells. Thus, regulatory cells can now be defined as both cells that suppress immune...... reactions as well as effector cells that counteract the effects of suppressor cells and support immune reactions. Self-reactive anti-Tregs have been described that specifically recognize human leukocyte antigen-restricted epitopes derived from proteins that are normally expressed by regulatory immune cells......Our initial understanding of immune-regulatory cells was based on the discovery of suppressor cells that assure peripheral T-cell tolerance and promote immune homeostasis. Research has particularly focused on the importance of regulatory T cells (Tregs) for immune modulation, e.g. directing host...

  16. Die Wêreldbond van Gereformeerde Kerke, die Nederduitse Gereformeerde Kerk en ’n status confessionis teen die teologiese en morele regverdiging van apartheid

    Directory of Open Access Journals (Sweden)

    Piet J. Strauss

    2015-07-01

    Full Text Available The World Alliance of Reformed Churches, the Dutch Reformed Church and a status confessionis against the theological and moral justification of apartheid. In 1982 the World Alliance of Reformed Churches (WARC announced a status confessionis against the theological and moral justification of apartheid. It expelled two member churches, the Dutch Reformed Church (DRC and the Netherdutch Reformed Church of Africa (Nederduitsch Hervormde Kerk van Afrika because of their known support of apartheid. This situation could only be changed if these two churches were to unequivocally reject apartheid on the basis of a status confessionis and show specified practical examples of this rejection. The meaning of a status confessionis as applied by the WARC is analysed. The reason why the WARC came to a status confessionis is historically investigated. The reaction of the DRC to this resolution and its readmittance as a member of the WARC is clarified. Attention is also given to the condition that accepting a status confessionis against the support of apartheid does not mean – for the WARC at least – that a new confession of faith should follow from this.

  17. Study of photosensitization reaction progress in a 96 well plate with photosensitizer rich condition using Talaporfin sodium

    Science.gov (United States)

    Ogawa, Emiyu; Takahashi, Mei; Arai, Tsunenori

    2013-02-01

    To quantitatively investigate photosensitization reaction in vitro against myocardial cells with photosensitizer rich condition in solution using Talaporfin sodium in the well of a 96 well plate, we studied photosensitization reaction progress in this well. We have proposed non-thermal conduction block of myocardium tissue using the photosensitization reaction with laser irradiation shortly after Talaporfin sodium injection. In above situation, the photosensitizer is located outside the myocardial cells in high concentration. To understand interaction of the photosensitization reaction in which the photosensitizer distributes outside cells, the photosensitization reaction progress in the well was studied. Talaporfin sodium (799.69 MW) solution and a 663 nm diode laser were used. The photosensitizer solution concentrations of 12.5-37.5 μM were employed. The photosensitizer fluorescence with 0.29 W/cm2 in irradiance, which was optimized in previous cell death study, was measured during the laser irradiation until 40 J/cm2. The photosensitizer solution absorbance and dissolved oxygen pressure after the laser irradiation were also measured. We found that the photosensitization reaction progress had 2 distinctive phases of different reaction rate: rapid photosensitization reaction consuming dissolved oxygen and gentle photosensitization reaction with oxygen diffusion from the solution-air boundary. The dissolved oxygen pressure and photosensitizer solution absorbance were 30% and 80% of the initial values after the laser irradiation, respectively. Therefore, oxygen was rate-controlling factor of the photosensitization reaction in the well with the photosensitizer rich condition. In the oxygen diffusion phase, the oxygen pressure was maintained around 40 mmHg until the laser irradiation of 40 J/cm2 and it is similar to that of myocardium tissue in vivo. We think that our 96 well plate in vitro system may simulate PDT in myocardial tissue with photosensitization reaction

  18. Reaction of Aluminum with Water to Produce Hydrogen - 2010 Update

    Energy Technology Data Exchange (ETDEWEB)

    Petrovic, John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Thomas, George [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2011-06-01

    A Study of Issues Related to the Use of Aluminum for On-Board Vehicular Hydrogen Storage The purpose of this White Paper is to describe and evaluate the potential of aluminum-water reactions for the production of hydrogen for on-board hydrogen-powered vehicle applications. Although the concept of reacting aluminum metal with water to produce hydrogen is not new, there have been a number of recent claims that such aluminum-water reactions might be employed to power fuel cell devices for portable applications such as emergency generators and laptop computers, and might even be considered for possible use as the hydrogen source for fuel cell-powered vehicles.

  19. Inhibition of the tissue reaction to a biodegradable biomaterial by monoclonal antibodies to IFN-gamma

    NARCIS (Netherlands)

    Khouw, IMSL; van Wachem, PB; de Leij, LFMH; van Luyn, MJA

    Biomaterials are increasingly used for clinical applications. However, loss of function may occur owing to tissue reactions, which are mainly caused by a variety of inflammatory reactions. Recently, we demonstrated that macrophages (MO) and T cells play key roles in these reactions. Since

  20. Stochastic reaction-diffusion algorithms for macromolecular crowding

    Science.gov (United States)

    Sturrock, Marc

    2016-06-01

    Compartment-based (lattice-based) reaction-diffusion algorithms are often used for studying complex stochastic spatio-temporal processes inside cells. In this paper the influence of macromolecular crowding on stochastic reaction-diffusion simulations is investigated. Reaction-diffusion processes are considered on two different kinds of compartmental lattice, a cubic lattice and a hexagonal close packed lattice, and solved using two different algorithms, the stochastic simulation algorithm and the spatiocyte algorithm (Arjunan and Tomita 2010 Syst. Synth. Biol. 4, 35-53). Obstacles (modelling macromolecular crowding) are shown to have substantial effects on the mean squared displacement and average number of molecules in the domain but the nature of these effects is dependent on the choice of lattice, with the cubic lattice being more susceptible to the effects of the obstacles. Finally, improvements for both algorithms are presented.

  1. Simultaneous Speciation of Arsenic, Selenium, and Chromium by HPLC-ICP-MS

    Science.gov (United States)

    Wolf, Ruth E.; Morman, Suzette A.; Morrison, Jean M.; Lamothe, Paul J.

    2008-01-01

    An adaptation of an analytical method developed for chromium speciation has been utilized for the simultaneous determination of As(III), As(V), Se(IV), Se(VI), Cr(III), and Cr(VI) species using high performance liquid chromatography (HPLC) separation with ICP-MS detection. Reduction of interferences for the determination of As, Se, and Cr by ICP-MS is a major consideration for this method. Toward this end, a Dynamic Reaction Cell (DRC) ICP-MS system was used to detect the species eluted from the chromatographic column. A variety of reaction cell gases and conditions may be utilized, and the advantages and limitations of the gases tested to date will be presented and discussed. The separation and detection of the As, Se, and Cr species of interest can be achieved using the same chromatographic conditions in less than 2 minutes by complexing the Cr(III) with EDTA prior to injection on the HPLC column. Practical aspects of simultaneous speciation analysis will be presented and discussed, including issues with HPLC sample vial contamination, standard and sample contamination, species stability, and considerations regarding sample collection and preservation methods. The results of testing to determine the method's robustness to common concomitant element and anion effects will also be discussed. Finally, results will be presented using the method for the analysis of a variety of environmental and geological samples including waters, soil leachates and simulated bio-fluid leachates.

  2. Quality and loudness judgments for music subjected to compression limiting.

    Science.gov (United States)

    Croghan, Naomi B H; Arehart, Kathryn H; Kates, James M

    2012-08-01

    Dynamic-range compression (DRC) is used in the music industry to maximize loudness. The amount of compression applied to commercial recordings has increased over time due to a motivating perspective that louder music is always preferred. In contrast to this viewpoint, artists and consumers have argued that using large amounts of DRC negatively affects the quality of music. However, little research evidence has supported the claims of either position. The present study investigated how DRC affects the perceived loudness and sound quality of recorded music. Rock and classical music samples were peak-normalized and then processed using different amounts of DRC. Normal-hearing listeners rated the processed and unprocessed samples on overall loudness, dynamic range, pleasantness, and preference, using a scaled paired-comparison procedure in two conditions: un-equalized, in which the loudness of the music samples varied, and loudness-equalized, in which loudness differences were minimized. Results indicated that a small amount of compression was preferred in the un-equalized condition, but the highest levels of compression were generally detrimental to quality, whether loudness was equalized or varied. These findings are contrary to the "louder is better" mentality in the music industry and suggest that more conservative use of DRC may be preferred for commercial music.

  3. 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.

  4. 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.

  5. The Type 1 Homodimeric Reaction Center in Heliobacterium modesticaldum

    Energy Technology Data Exchange (ETDEWEB)

    Golbeck, John [Pennsylvania State Univ., University Park, PA (United States)

    2018-01-15

    In this funding period, we (i) found that strong illumination of Heliobacterium modesticaldum cells results in saturation of the electron acceptor pool, leading to reduction of the acceptor side and the creation of a back-reacting state that gives rise to delayed fluorescence; (ii) noted that when the FX cluster is reduced in purified reaction centers, no electron transfer occurs beyond A0, even though a quinone is present; (iii) observed by photochemically induced dynamic nuclear polarization (photo-CIDNP) studies of whole cells of Heliobacterium mobilis that primary charge separation is retained even after conversion of the majority of BChl g to Chl aF. ; and (iv) purified a homogeneous preparation of reaction center cores, which led to promising crystallization trials to obtain a three-dimensional structure.

  6. The human sunburn reaction: histologic and biochemical studies

    International Nuclear Information System (INIS)

    Gilchrest, B.A.; Soter, N.A.; Stoff, J.S.; Mihm, M.C. Jr.

    1981-01-01

    The ultraviolet-induced erythema reaction was investigated histologically and biochemically in four subjects, utilizing suction blister aspirates, analyzed for histamine and prostaglandin E2 (PGE2), and Epon-embedded 1-mu skin biopsy sections from control skin and from irradiated skin at intervals for 72 hours after exposure to a Hanovia lamp. Major histologic alterations in the epidermis included dyskeratotic and vacuolated keratinocytes (sunburn cells), and disappearance of Langerhans cells. In the dermis the major changes were vascular, involving both the superficial and deep venular plexuses. Endothelial cell enlargement was first apparent within 30 minutes of irradiation, peaked at 24 hours, and persisted throughout the 72-hour study period. Mast cell degranulation and associated perivenular edema were first apparent at 1 hour and striking at the onset of erythema, 3 to 4 hours postirradiation; edema was absent and mast cells were again normal in number and granule content at 24 hours. Histamine levels rose approximately fourfold above control values immediately after the onset of erythema and returned to baseline within 24 hours. PGE2 levels were statistically elevated even before the onset of erythema and reached approximately 150% of the control value at 24 hours. These data provide the first evidence that histamine may mediate the early phase of the human sunburn reaction and increase our understanding of its complex histologic and biochemical sequelae

  7. A qualitative analysis of psychosocial outcomes among women with sexual violence-related pregnancies in eastern Democratic Republic of Congo.

    Science.gov (United States)

    Scott, Jennifer; Mullen, Colleen; Rouhani, Shada; Kuwert, Philipp; Greiner, Ashley; Albutt, Katherine; Burkhardt, Gillian; Onyango, Monica; VanRooyen, Michael; Bartels, Susan

    2017-01-01

    Sexual violence is prevalent in eastern Democratic Republic of Congo (DRC) and has potentially devastating psychosocial consequences. Previous studies have reported on sexual violence and its impact on the mental health of survivors, but there are few studies conducted among women with sexual violence-related pregnancies (SVRPs). Women with SVRPs may be at greater risk of complex psychosocial outcomes, including social stigmatization. This study aimed to describe psychosocial outcomes among this subgroup of sexual violence survivors in order to inform future interventions. A mixed methods study was conducted in Bukavu, DRC in 2012 among adult women who self-reported an SVRP and either (1) were currently raising a child from an SVRP (parenting group) or (2) had terminated an SVRP (termination group). This manuscript presents qualitative findings from the mixed methods study. Participants were recruited using respondent-driven sampling and a proportion engaged in semi-structured qualitative interviews conducted by trained female interviewers. Thematic content analysis was conducted and key themes were identified. In total, 55 women were interviewed, of whom 38 were in the parenting group and 17 in the termination group. Women with SVRPs experienced a myriad of emotional responses as they navigated their social environments following the SVRPs. Negative reactions, including social stigmatization and/or social rejection, toward women with SVRPs and toward children born from SVRPs were important influences on psychological well-being. Women expressed both internalized emotionality intertwined with externalized experiences in the social environment. Many women demonstrated resilience, or what could be termed post-traumatic growth, identifying avenues of agency to advance the social conditions for women. The findings from the qualitative study, and in particular, the respondents' needs and suggested strategies, may be useful to inform future research, programs, and

  8. Detection of Mycobacterium tuberculosis in clinical samples by two-step polymerase chain reaction and nonisotopic hybridization methods.

    OpenAIRE

    Shawar, R M; el-Zaatari, F A; Nataraj, A; Clarridge, J E

    1993-01-01

    Detection of Mycobacterium tuberculosis in clinical specimens by the polymerase chain reaction (PCR) was compared with detection by culture. A 317-bp segment within the M. tuberculosis-specific insertion sequence IS6110 was amplified. The detection limit of the PCR assay for cultured mycobacteria was 50 cells per reaction by ethidium bromide-stained agarose gel electrophoresis and 5 cells per reaction by hybridization with an oligonucleotide probe conjugated with either digoxigenin or alkalin...

  9. Challenges Towards Sustainable Peace and Security: in the ...

    African Journals Online (AJOL)

    This article analyses the structural challenges facing the new government of the. Democratic Republic of Congo (DRC) in its reconstruction and development programme for sustainable peace and security. It takes into account the DRC's strategic importance in the Central and Southern African region and the African ...

  10. 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)

  11. 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.

  12. Níveis séricos de vitamina D e periodontite crônica em pacientes com doença renal crônica

    Directory of Open Access Journals (Sweden)

    Jessica do Amaral Bastos

    2013-03-01

    Full Text Available INTRODUÇÃO A concomitância de periodontite crônica (PC em pacientes com doença renal crônica (DRC tem sido associada a desfechos adversos. A deficiência de vitamina D (25(OHD parece desempenhar papel importante na PC e níveis inadequados de vitamina D têm sido descritos em pacientes com DRC. OBJETIVO: Examinar a relação entre níveis séricos de vitamina D e PC em pacientes com DRC pré-dialítica. MÉTODO: Estudo de caso-controle, definidos, respectivamente, como pacientes com DRC e PC e DRC sem PC. Os dados demográficos, de exame físico e laboratoriais foram obtidos no dia da consulta. A DRC foi definida e estagiada segundo a NKF QDOKI TM. Os níveis séricos de 25(OH D foram dosados por quimioluminescência quando da avaliação da PC, a qual foi caracterizada segundo os critérios de Academia Americana de Periodontologia (1999. Os resultados de 25(OHD foram estratificados em deficiência ( 30 ηg/mL. RESULTADOS: Um total de 29 pacientes foram estudados, 15 no grupo caso e 14 no grupo controle. Os pacientes casos apresentaram mediana de 25(OH D inferior a dos pacientes controles (22,6 vs. 28,6 ηg/mL; p < 0,01. A frequência de pacientes casos com insuficiência/deficiência de vitamina D foi maior do que entre os pacientes controles (93,3% vs. 57,1%, p < 0,004. Por outro lado, o percentual de pacientes com suficiência de vitamina D foi maior entre os controles se comparados aos integrantes do grupo casos (42,9% vs. 6,7%, p < 0,004. CONCLUSÃO: Em pacientes com DRC, a deficiência de vitamina D se associa com PC.

  13. Inertial effects in diffusion-limited reactions

    International Nuclear Information System (INIS)

    Dorsaz, N; Foffi, G; De Michele, C; Piazza, F

    2010-01-01

    Diffusion-limited reactions are commonly found in biochemical processes such as enzyme catalysis, colloid and protein aggregation and binding between different macromolecules in cells. Usually, such reactions are modeled within the Smoluchowski framework by considering purely diffusive boundary problems. However, inertial effects are not always negligible in real biological or physical media on typical observation time frames. This is all the more so for non-bulk phenomena involving physical boundaries, that introduce additional time and space constraints. In this paper, we present and test a novel numerical scheme, based on event-driven Brownian dynamics, that allows us to explore a wide range of velocity relaxation times, from the purely diffusive case to the underdamped regime. We show that our algorithm perfectly reproduces the solution of the Fokker-Planck problem with absorbing boundary conditions in all the regimes considered and is thus a good tool for studying diffusion-guided reactions in complex biological environments.

  14. Enrichment: CRISLA [chemical reaction by isotope selective activation] aims to reduce costs

    International Nuclear Information System (INIS)

    Eerkens, J.W.

    1989-01-01

    Every year, more than $3 billion is spent on enriching uranium. CRISLA (Chemical Reaction by Isotope Selective Activation) uses a laser-catalyzed chemical reaction which, its proponents claim, could substantially reduce these costs. In CRISLA, an infrared CO laser illuminates the intracavity reaction cell (IC) at a frequency tuned to excite primarily UF 6 . When UF 6 and co-reactant RX are passed through the IC, the tuned laser photons preferentially enhance the reaction of UF 6 with RX ten-thousand-fold over the thermal reaction rate. Thus the laser serves as an activator and the chemical energy for separation is largely chemical. (author)

  15. 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

  16. Importance of the support and the grade of Pt in the oxygen reduction reaction

    International Nuclear Information System (INIS)

    Enriquez M, O.; Fernandez V, S.M.

    2004-01-01

    The technology of the fuel cells type Proton Exchange Membrane (PEM), needs to define clearly the influence of the different involved parameters, this is made in general using methods of electrochemical impedance, in which the involved reactions can be presupposed. Another form of making is identifying experimentally the influence of the different parameters. In this work the obtained results are reported with for the oxygen reduction reaction using as electro catalyst platinum analytical grade and fuel cell grade and like support graphite and vulcan. It was found that as much the support as the particle size modify the over potential for the oxygen reduction reaction (Orr). (Author)

  17. 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.

  18. 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.

  19. 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.

  20. Gigantocellular macrophagal reaction in epidermoid cancer of the lung in patients exposed to preoperative irradiation

    International Nuclear Information System (INIS)

    Galil-Ogly, G.A.; Kharchenko, V.P.; Poroshin, K.K.; Pereslegin, O.I.; Krylov, L.M.; Ivanov, E.D.

    1980-01-01

    The histologic and electron microscopic study of frequently occurring gigantocellular macrophagal reaction in the stroma of 83 irradiated epidermoid carcinomas of the lung is carried out. It is found that gigantic multinuclear macrophages take part in the resorption of necrotic and corneous masses as well as in the absorption of viable tumour cells. The presence of gigantocellular macrophagal reaction in the stroma of irradiated tumoUr evidences a more favourable prognosis in patients after the combined treatment of epidermoid lung cancer. Gigantocellular macrophagal reaction should be considered as the manifestation of cell antitumour immunity which makes stronger the tumour irradiation damage

  1. "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

  2. 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....

  3. 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.

  4. 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.

  5. Esterase reactions in acute myelomonocytic leukemia.

    Science.gov (United States)

    Kass, L

    1977-05-01

    Specific and nonspecific esterase reactions of bone marrow cells from 14 patients with untreated acute myelomonocytic leukemia and six patients with acute histiomonocytic leukemia were examined. The technic for esterase determination permitted simultaneous visualization of both esterases on the same glass coverslip containing the marrow cells. In cases of acute histiomonocytic leukemia, monocytes, monocytoid hemohistioblasts and undifferentiated blasts stained intensely positive for nonspecific esterase, using alpha-naphthyl acetate as the substrate. No evidence of specific esterase activity using naphthol ASD-chloroacetate as the substrate and fast blue BBN as the dye coupler was apparent in these cells. In all of the cases of acute myelomonocytic leukemia, both specific and nonspecific esterases were visualized within monocytes, monocytoid cells, and granulocytic cells that had monocytoid-type nuclei. Nonspecific esterase activity was not observed in polymorphonuclear leukocytes in cases of myelomonocytic leukemia. The results support a current viewpoint that acute myelomonocytic leukemia may be a variant of acute myeloblastic leukemia, and that cytochemically, many of the leukemic cells in myelomonocytic leukemia share properties of both granulocytes and monocytes.

  6. 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

  7. Heath sector network governance and State-building in South Kivu, Democratic Republic of Congo

    NARCIS (Netherlands)

    Bwimana, Aembe

    2017-01-01

    Longstanding patterns of interaction exist between state and non-state actors seeking to improve public health in Democratic Republic of Congo (DRC). DRC is a weak state, and, in many cases, private actors have stepped in to fill the void created by the lack of state health care provision. However,

  8. Effects of import tariff implementation policy of refined sugar ...

    African Journals Online (AJOL)

    The competitiveness of sugar products in Indonesia was evaluated using the of East Java wet and dry farmlands and was found to be higher than similar products from overseas as shown by DRC value of less than 1. Keyword: Sugar, Welfare distribution, Domestic Resource Cost (DRC), import tariff, Indonesia ...

  9. Effect Of Import Tariff Implementation Policy On Refined Sugar ...

    African Journals Online (AJOL)

    economization, are influenced by the import tariff and elasticity price toward supply and demand. It also showed that sugar product competitiveness in Indonesia is higher than the same product from other countries as the value of DRC is less than one. Key word: Sugar, Welfare Distribution, Domestic Resource Cost (DRC), ...

  10. 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.

  11. 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.

  12. Ambient Mechanochemical Solid-State Reactions of Carbon Nanotubes and Their Reactions via Covalent Coordinate Bond in Solution

    Science.gov (United States)

    Kabbani, Mohamad A.

    In its first part, this thesis deals with ambient mechanochemical solid-state reactions of differently functionalized multiple walled carbon nanotubes (MWCNTs) while in its second part it investigates the cross-linking reactions of CNTs in solution via covalent coordinate bonds with transitions metals and carboxylate groups decorating their surfaces. In the first part a series of mechanochemical reactions involving different reactive functionalities on the CNTs such as COOH/OH, COOH/NH2 and COCl/OH were performed. The solid-state unzipping of CNTs leading to graphene formation was confirmed using spectroscopic, thermal and electron microscopy techniques. The non-grapheme products were established using in-situ quadruple mass spectroscopy. The experimental results were confirmed by theoretical simulation calculations using the 'hot spots' protocol. The kinetics of the reaction between MWCNT-COOH and MWCNT-OH was monitored using variable temperature Raman spectroscopy. The low activation energy was discussed in terms of hydrogen bond mediated proton transfer mechanism. The second part involves the reaction of MWCNTII COOH with Zn (II) and Cu (II) to form CNT metal-organic frame (MOFs) products that were tested for their effective use as counter-electrodes in dyes sensitized solar cells (DSSC). The thesis concludes by the study of the room temperature reaction between the functionalized graphenes, GOH and G'-COOH followed by the application of compressive loads. The 3D solid graphene pellet product ( 0.6gm/cc) is conductive and reflective with a 35MPa ultimate strength as compared to 10MPa strength of graphite electrode ( 2.2gm/cc).

  13. 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.

  14. Stochastic simulation of biological reactions, and its applications for studying actin polymerization.

    Science.gov (United States)

    Ichikawa, Kazuhisa; Suzuki, Takashi; Murata, Noboru

    2010-11-30

    Molecular events in biological cells occur in local subregions, where the molecules tend to be small in number. The cytoskeleton, which is important for both the structural changes of cells and their functions, is also a countable entity because of its long fibrous shape. To simulate the local environment using a computer, stochastic simulations should be run. We herein report a new method of stochastic simulation based on random walk and reaction by the collision of all molecules. The microscopic reaction rate P(r) is calculated from the macroscopic rate constant k. The formula involves only local parameters embedded for each molecule. The results of the stochastic simulations of simple second-order, polymerization, Michaelis-Menten-type and other reactions agreed quite well with those of deterministic simulations when the number of molecules was sufficiently large. An analysis of the theory indicated a relationship between variance and the number of molecules in the system, and results of multiple stochastic simulation runs confirmed this relationship. We simulated Ca²(+) dynamics in a cell by inward flow from a point on the cell surface and the polymerization of G-actin forming F-actin. Our results showed that this theory and method can be used to simulate spatially inhomogeneous events.

  15. Stochastic simulation of biological reactions, and its applications for studying actin polymerization

    International Nuclear Information System (INIS)

    Ichikawa, Kazuhisa; Suzuki, Takashi; Murata, Noboru

    2010-01-01

    Molecular events in biological cells occur in local subregions, where the molecules tend to be small in number. The cytoskeleton, which is important for both the structural changes of cells and their functions, is also a countable entity because of its long fibrous shape. To simulate the local environment using a computer, stochastic simulations should be run. We herein report a new method of stochastic simulation based on random walk and reaction by the collision of all molecules. The microscopic reaction rate P r is calculated from the macroscopic rate constant k. The formula involves only local parameters embedded for each molecule. The results of the stochastic simulations of simple second-order, polymerization, Michaelis–Menten-type and other reactions agreed quite well with those of deterministic simulations when the number of molecules was sufficiently large. An analysis of the theory indicated a relationship between variance and the number of molecules in the system, and results of multiple stochastic simulation runs confirmed this relationship. We simulated Ca 2+ dynamics in a cell by inward flow from a point on the cell surface and the polymerization of G-actin forming F-actin. Our results showed that this theory and method can be used to simulate spatially inhomogeneous events

  16. Metabolic and physiologic studies of nonimmune lymphoid cells cytotoxic for fibroblastic cells in vitro

    International Nuclear Information System (INIS)

    Mayhew, E.; Bennett, M.

    1974-01-01

    An in vitro reaction between mouse lymphoid cells and target fibroblastic cells in wells of microtest plates, which appears to simulate the in vivo rejection of hemopoietic allografts, has been analyzed for metabolic and physiologic requirements. Protein synthesis was required for only the first few hours of culture. Inhibition of RNA synthesis and alteration of cell surface charge with various agents were without obvious effects. Metabolic slowing at 4 0 C or deviation of the pH of the culture medium suppressed the reaction. Thymus cells, which are not cytotoxic in this system, significantly but not completely inhibited the cytotoxicity of lymph node cells. Antiserum directed against target cells specifically protected them from the cytotoxic lymphoid cells in the absence of complement. Precursors of cytotoxic lymphoid cells were radiosensitive, unlike the cytotoxic cells themselves. BALB/c anti-C57BL/6 spleen cell serum and 89 Sr both are able to prevent rejection of marrow allografts in vivo. Lymphoid cells incubated with this antiserum plus complement lost much of their cytotoxicity but were still effective at high ratios of aggressor to target cells. Lymphoid cells of mice treated with 89 Sr were effectively cytotoxic but lost practically all of their cytotoxicity after incubation with the antiserum plus complement. Thus, it appears that this reaction detects two different cytotoxic lymphoid cells, either of which can function in vitro. Both cell types may need to cooperate in vivo during marrow allograft rejections

  17. Radiation therapy and late reactions in normal tissues

    International Nuclear Information System (INIS)

    Aoyama, Takashi; Kuroda, Yasumasa

    1998-01-01

    Recent developments in cancer therapy have made us increasingly aware that the quality of life of a patient is as valuable as other benefits received from therapy. This awareness leads to an emphasis on organ and/or function preservation in the course of therapy. In line with this new thinking, greater consideration is placed on radiation therapy as an appropriate modality of cancer therapy. Possible complications in normal tissues, especially those of late reaction type after the therapy must be overcome. This review, therefore, focuses on recent progress of studies on mechanisms of the complications of the late reaction type. An observation of a clinical case concerning a late reaction of spinal cord (radiation myelopathy) and surveys of experimental studies on the mechanisms of late reactions (including radiation pneumonitis and lung fibrosis, and radiation response of vascular endothelial cells) provide a hypothesis that apoptosis through the pathway starting with radiation-induced sphingomyelin hydrolysis may play an important role in causing a variety of late reactions. This insight is based on the fact that radiation also activates protein kinase C which appears to block apoptosis. The mechanisms of late reactions, therefore, may involve a balance between radiation-induced apoptotic death and its down regulation by suppressor mechanisms through protein kinase C. (author)

  18. Mathematical modelling of light-induced electric reaction of Cucurbita pepo L. leaves

    Directory of Open Access Journals (Sweden)

    Jan Stolarek

    2014-01-01

    Full Text Available The bioelectRIc reactions of 14-16 day old plants of pumpkin (Cucurbita pepo L. and internodal cells of Nitellopsis obtusa to the action of visible and ultraviolet light (UV-C were studied. The possibility of analyzing the bioelectric reaction of pumpkin plants induced by visible light by means of mathematical modelling using a linear differential equation of the second order was considered. The solution of this equation (positive and negative functions can, in a sufficient way, reflect the participation of H+ and CI- ions in the generation of the photoelectric response in green plant cells.

  19. Sintering with a chemical reaction as applied to uranium monocarbide; Frittage-reaction dans le cas du monocarbure d'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Accary, A; Caillat, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The present paper provides a survey of different investigations whose aim was the preparation and fabrication of uranium monocarbide for nuclear use. If a chemical reaction takes place in the sample during the sintering operation, it may be expected that the atom rearrangements involved in this reaction should favour the sintering process and thereby lower the temperature needed to yield a body of a given density. With this hypothesis in mind, the following methods have been studied: - Sintering of U-C mixtures; - Sintering of UO{sub 2}-C mixtures; - Hot pressing of U-C mixtures; - Extrusion of U-C mixtures. To generalize our result, it could be said that a chemical reaction does not lead to high densification, if one depends on a simple contact between discrete particles. On the contrary, a chemical reaction can help sintering if, as our hot pressing experiments shows, the densification can be achieved prior to the reaction. (author) [French] Le present article resume les etudes faites pour le compte du Commissariat a l'Energie Atomique dans le but de preparer du monocarbure d'uranium pour usage nucleaire. Si, en meme temps que l'on fritte une poudre, celle-ci est le siege d'une reaction chimique, on peut s'attendre a ce que le rearrangement atomique d'une reaction chimique favorise le frittage et, ainsi abaisse la temperature de travail necessaire pour obtenir une densite donnee. Nous avons etudie les methodes suivantes: - frittage des melanges U-C; - frittage des melanges UO{sub 2}-C; - frittage sous charge des melanges U-C; - filage des melanges U-C. Nos resultats montrent qu'une reaction chimique en cours de frittage ne conduit pas a un produit de haute densite si on opere sur un melange de poudres. Par contre, elle permet d'atteindre de hautes densites si la densification peut etre obtenue avant la reaction chimique. (auteur)

  20. A mathematical analysis of Prx2-STAT3 disulfide exchange rate constants for a bimolecular reaction mechanism.

    Science.gov (United States)

    Langford, Troy F; Deen, William M; Sikes, Hadley D

    2018-03-22

    Appreciation of peroxiredoxins as the major regulators of H 2 O 2 concentrations in human cells has led to a new understanding of redox signaling. In addition to their status as the primary reducers of H 2 O 2 to water, the oxidized peroxiredoxin byproduct of this reaction has recently been shown capable of participation in H 2 O 2 -mediated signaling pathways through disulfide exchange reactions with the transcription factor STAT3. The dynamics of peroxidase-transcription factor disulfide exchange reactions have not yet been considered in detail with respect to how these reactions fit into the larger network of competing reactions in human cells. In this study, we used a kinetic model of oxidation and reduction reactions related to H 2 O 2 metabolism in the cytosol of human cells to study the dynamics of peroxiredoxin-2 mediated oxidation of the redox-regulated transcription factor STAT3. In combination with previously reported experimental data, the model was used to estimate the rate coefficient of a biomolecular reaction between Prx2 and STAT3 for two sets of assumptions that constitute lower and upper bound cases. Using these estimates, we calculated the relative rates of the reaction of oxidized peroxiredoxin-2 and STAT3 and other competing reactions in the cytosol. These calculations revealed that peroxiredoxin-2-mediated oxidation of STAT3 likely occurs at a much slower rate than competing reactions in the cytosol. This analysis suggests the existence of more complex mechanisms, potentially involving currently unknown protein-protein recognition partners, which facilitate disulfide exchange reactions between peroxiredoxin-2 and STAT3. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Religious Networks in Post-conflict Democratic Republic of the ...

    African Journals Online (AJOL)

    With reference to the Democratic Republic of the Congo (DRC), religious groups wield enormous influence in the public space as providers of social services in a polity that has been characterised by years of misrule, declining state capacity and protracted conflict. The conflict in the DRC has deepened the imperative for ...

  2. Trans-methylation reactions in plants: focus on the activated methyl cycle.

    Science.gov (United States)

    Rahikainen, Moona; Alegre, Sara; Trotta, Andrea; Pascual, Jesús; Kangasjärvi, Saijaliisa

    2018-02-01

    Trans-methylation reactions are vital in basic metabolism, epigenetic regulation, RNA metabolism, and posttranslational control of protein function and therefore fundamental in determining the physiological processes in all living organisms. The plant kingdom is additionally characterized by the production of secondary metabolites that undergo specific hydroxylation, oxidation and methylation reactions to obtain a wide array of different chemical structures. Increasing research efforts have started to reveal the enzymatic pathways underlying the biosynthesis of complex metabolites in plants. Further engineering of these enzymatic machineries offers significant possibilities in the development of bio-based technologies, but necessitates deep understanding of their potential metabolic and regulatory interactions. Trans-methylation reactions are tightly coupled with the so-called activated methyl cycle (AMC), an essential metabolic circuit that maintains the trans-methylation capacity in all living cells. Tight regulation of the AMC is crucial in ensuring accurate trans-methylation reactions in different subcellular compartments, cell types, developmental stages and environmental conditions. This review addresses the organization and posttranslational regulation of the AMC and elaborates its critical role in determining metabolic regulation through modulation of methyl utilization in stress-exposed plants. © 2017 Scandinavian Plant Physiology Society.

  3. State of the art and prospective of lipase-catalyzed transesterification reaction for biodiesel production

    International Nuclear Information System (INIS)

    Amini, Zeynab; Ilham, Zul; Ong, Hwai Chyuan; Mazaheri, Hoora; Chen, Wei-Hsin

    2017-01-01

    Highlights: • Enzymatic transesterification process is less energy intensive and robust. • Nano-materials are promising immobilization supports for lipase. • Packed-bed reactors are appropriate for scale-up use. • Potential recombinant, whole cell and recombinant whole cell lipases were enlisted. • Genetic engineering is a promising prospect in biodiesel area. - Abstract: The world demand for fuel as energy sources have arisen the need for generating alternatives such as biofuel. Biodiesel is a renewable fuel used particularly in diesel engines. Currently, biodiesel is mainly produced through transesterification reactions catalyzed by chemical catalysts, which produces higher fatty acid alkyl esters in shorter reaction time. Although extensive investigations on enzymatic transesterification by downstream processing were carried out, enzymatic transesterification has yet to be used in scale-up since commercial lipases are chiefly limited to the cost as well as long reaction time. While numerous lipases were studied and proven to have the high catalytic capacity, still enzymatic reaction requires more investigation. To fill this gap, finding optimal conditions for the reaction such as alcohol and oil choice, water content, reaction time and temperature through proper reaction modelling and simulations as well as the appropriate design and use of reactors for large scale production are crucial issues that need to be accurately addressed. Furthermore, lipase concentration, alternative lipase resources through whole cell technology and genetic engineering, recent immobilizing materials including nanoparticles, and the capacity of enzyme to be reused are important criteria to be neatly investigated. The present work reviews the current biodiesel feedstock, catalysis, general and novel immobilizing materials, bioreactors for enzymatic transesterification, potential lipase resources, intensification technics, and process modelling for enzymatic

  4. 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.

  5. 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.

  6. Simultaneous fingering, double-diffusive convection, and thermal plumes derived from autocatalytic exothermic reaction fronts

    Science.gov (United States)

    Eskew, Matthew W.; Harrison, Jason; Simoyi, Reuben H.

    2016-11-01

    Oxidation reactions of thiourea by chlorite in a Hele-Shaw cell are excitable, autocatalytic, exothermic, and generate a lateral instability upon being triggered by the autocatalyst. Reagent concentrations used to develop convective instabilities delivered a temperature jump at the wave front of 2.1 K. The reaction zone was 2 mm and due to normal cooling after the wave front, this generated a spike rather than the standard well-studied front propagation. The reaction front has solutal and thermal contributions to density changes that act in opposite directions due to the existence of a positive isothermal density change in the reaction. The competition between these effects generates thermal plumes. The fascinating feature of this system is the coexistence of plumes and fingering in the same solution which alternate in frequency as the front propagates, generating hot and cold spots within the Hele-Shaw cell, and subsequently spatiotemporal inhomogeneities. The small ΔT at the wave front generated thermocapillary convection which competed effectively with thermogravitational forces at low Eötvös Numbers. A simplified reaction-diffusion-convection model was derived for the system. Plume formation is heavily dependent on boundary effects from the cell dimensions. This work was supported by Grant No. CHE-1056366 from the NSF and a Research Professor Grant from the University of KwaZulu-Natal.

  7. A study of immunological reactions in dogs exposed to prolonged chronic radiation

    Science.gov (United States)

    Konstantinova, I. V.; Grigoryev, Y. G.; Markelov, B. A.; Skryabin, A. S.; Zemskov, V. M.; Vasilyev, I. S.; Veysfeyler, Y. K.; Iokai, I.

    1974-01-01

    Immunomorphological studies on dog tissues exposed to long term gamma irradiation show that the number of cells containing antibodies increased and that the blast transformation reaction was activated. Prolonged radiation did not cause a reliable change in the synthesis of nucleic acids in spleen cells.

  8. Proliferative activity as a prognostic factor of a human tumor radiation reactions

    International Nuclear Information System (INIS)

    Karakulov, R.K.; Pelevina, I.I.

    1986-01-01

    The following questions are considered: 1) whether cell proliferation initial parameters can serve for predicting the tumor radial reaction; 2) whether proliferative activity change can be a criterion for estimating the treatment efficiency; 3) acquisition of data on biological peculiarities of different types of tumors. Connection between proliferative activity drop and clinical reaction under tumor radiotherapy is ascertained

  9. Induction of Hypozincemia and Hepatic Metallothionein Synthesis in Hypersensitivity Reactions.

    Science.gov (United States)

    1978-06-19

    cells to produce endogenous pyrogen (EP), the mediator of febrile response. Controversial evidence exists, however , concerning the differentiation of LEM...hypersensitivity reactions, Kampschmid t and Pulliam (1) proposed that leukocytic endogenous mediator (LEN) is released from phagocytic cells after... endogenous mediator(s) such as LEN, no conclusive evidence is available to indicate a mRNA requirement for the production of potential mediator(s

  10. 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...

  11. O tratamento da doenca renal cronica pode afetar a audicao?

    Directory of Open Access Journals (Sweden)

    Priscila Suman Lopez

    2014-01-01

    Full Text Available Introdução: Doença renal crônica (DRC é definida pela presença de lesão renal levando à perda lenta e progressiva da função renal. Objetivo: Comparar testes auditivos entre pacientes com DRC submetidos a diferentes método de tratamento. Material e método: Estudo clínico transversal. Os grupos foram divididos de acordo com o método de tratamento: hemodiálise (n = 35, diálise peritoneal (n =15, conservador (n = 51 e 27 pacientes saudáveis (controle. Pacientes com idade superior a 60 anos, perda auditiva congênita, síndromes genéticas, infecções de orelha média e transplante renal foram excluídos da pesquisa. A avaliação audiológica incluiu audiometria tonal, emissões otoacústicas evocadas transientes e Potencial Evocado Auditivo de Tronco Encefálico (PEATE; e as variáveis avaliadas foram: sexo, idade, diagnóstico de hipertensão arterial e diabetes, estádio da DRC, tempo de diagnóstico do diabetes e da hipertensão arterial, duração da DRC e do tratamento. Resultados: A idade, presença de hipertensão arterial e tempo de DRC foram estatisticamente significantes e controlados. O grupo conservador apresentou piores limiares auditivos na audiometria tonal e o intervalo III-V do PEATE significativamente maior que o da hemodiálise. Conclusão: O tratamento conservador mostrou piores resultados na avaliação auditiva, independente de diabetes e de hipertensão, reforçando que os pacientes submetidos a tratamento para DRC devem realizar avaliação auditiva completa para melhor compreensão da doença e de seus efeitos sobre o sistema auditivo.

  12. Factors affecting the autologous mixed lymphocyte reaction in kidney transplantation

    International Nuclear Information System (INIS)

    Fuller, L.; Flaa, C.; Jaffe, D.; Strauss, J.; Kyriakides, G.K.; Miller, J.

    1983-01-01

    In long-term well adapted kidney transplant recipients we have found a close correlation between the T helper (TH):T suppressor/cytotoxic (TS/C) subset ratios and the presence of T cells that respond in the autologous mixed lymphocyte reaction (AMLR). In 21 recipients with T cell E rosette levels ranging between 53 and 86% and TH:TS/C ratios between 0.15 to 2.10, ratios of greater than 0.8 correlated with AMLR responses (13/13), and ratios of less than 0.8 with AMLR nonreactivity (7/7). By contrast, the allogeneic MLR showed no apparent correlation with the TH:TS/C ratios or with the AMLR pre- or postoperatively. It was found that the AMLR in 22 of 23 normal individuals was markedly inhibited by autologous T cells obtained from peripheral blood lymphocytes, exposed to 3,000 rad (Tx) and added as a third component to the cultures. In contrast, 13 of 13 kidney transplant recipients failed to exhibit this Tx AMLR inhibitory cell population. The ''naturally occurring'' T inhibitory cells, fractionated by an affinity column chromatography procedure into x-irradiated TH and TS/C subsets, inhibited the AMLR to the same extent as unseparated Tx cells. In cell interchange studies performed in four of five HLA identical donor-recipient pairs the Tx cells of the (normal) donor inhibited the recipient AMLR (immunosuppressed), but recipient Tx cells failed to inhibit the donor AMLR. Finally T cells, primed in AMLR and allogeneic MLR for 10 d were tested for AMLR or allogeneic MLR inhibitory activity. Allogeneic MLR primed x-irradiated cells, inhibited both the AMLR and allogeneic MLR while AMLR x-irradiated primed cells inhibited neither reaction. The Tx AMLR inhibitor found in normal peripheral blood, appears to be a cell that is highly sensitive to the effects of biologic or pharmacologic immunosuppressive agents

  13. Fiber coating/matrix reactions in silicon-base ceramic matrix composites

    International Nuclear Information System (INIS)

    Lee, K.N.; Jacobson, N.S.

    1992-01-01

    The Knudsen cell technique and coupons of carbon coated Si3N4 and BN coated SiC were employed to study the possible reactions at the SiC/C/Si3N4 and SiC/BN/SiC interface. Carbon reacts with Si3N4 to form gaseous N2 and solid SiC. Solid SiC acts as a physical barrier to the reaction, which prevents the generation of high N2 pressure predicted from thermochemical calculations. Thus, deleterious effects of the reaction to the composite are limited. Limited reactions between BN and C-rich SiC was observed. However, the vapor pressure was so low that it is not likely to cause any interfacial instability. The predicted formation of a BN-C solid solution was not observed. 10 refs

  14. Fiber coating/matrix reactions in silicon-base ceramic matrix composites

    Science.gov (United States)

    Lee, K. N.; Jacobson, N. S.

    1992-01-01

    The Knudsen cell technique and coupons of carbon coated Si3N4 and BN coated SiC were employed to study the possible reactions at the SiC/C/Si3N4 and SiC/BN/SiC interface. Carbon reacts with Si3N4 to form gaseous N2 and solid SiC. Solid SiC acts as a physical barrier to the reaction, which prevents the generation of high N2 pressure predicted from thermochemical calculations. Thus, deleterious effects of the reaction to the composite are limited. Limited reactions between BN and C-rich SiC was observed. However, the vapor pressure was so low that it is not likely to cause any interfacial instability. The predicted formation of a BN-C solid solution was not observed.

  15. A light water excess heat reaction suggests that cold fusion may be alkali-hydrogen fusion

    International Nuclear Information System (INIS)

    Bush, R.T.

    1992-01-01

    This paper reports that Mills and Kneizys presented data in support of a light water excess heat reaction obtained with an electrolytic cell highly reminiscent of the Fleischmann-Pons cold fusion cell. The claim of Mills and Kneizys that their excess heat reaction can be explained on the basis of a novel chemistry, which supposedly also explains cold fusion, is rejected in favor of their reaction being, instead, a light water cold fusion reaction. It is the first known light water cold fusion reaction to exhibit excess heat, it may serve as a prototype to expand our understanding of cold fusion. From this new reactions are deduced, including those common to past cold fusion studies. This broader pattern of nuclear reactions is typically seen to involve a fusion of the nuclides of the alkali atoms with the simplest of the alkali-type nuclides, namely, protons, deuterons, and tritons. Thus, the term alkali-hydrogen fusion seems appropriate for this new type of reaction with three subclasses: alkali-hydrogen fusion, alkali-deuterium fusion, and alkali-tritium fusion. A new three-dimensional transmission resonance model (TRM) is sketched. Finally, preliminary experimental evidence in support of the hypothesis of a light water nuclear reaction and alkali-hydrogen fusion is reported. Evidence is presented that appears to strongly implicate the transmission resonance phenomenon of the new TRM

  16. 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

  17. Evaluation of reaction selectivity at various Pt/C electrocatalysts using a porous microelectrode in the presence of methanol and oxygen

    International Nuclear Information System (INIS)

    Shironita, Sayoko; Zhang, Weiqi; Sakai, Tsukasa; Umeda, Minoru

    2014-01-01

    Pt is most useful metal for various electrochemical reactions as an electrocatalyst. In a direct methanol fuel cell, Pt performs a catalytic activity for both the methanol oxidation reaction and oxygen reduction reaction; therefore, a Pt-based catalyst is used as an anode and a cathode. For the coexistence of methanol and oxygen due to methanol crossover through an electrolyte membrane during the cell operation, the direct methanol fuel cell performance decreases. However, if a higher selective reaction electrocatalyst can be developed, the cell performance will not be suppressed. In this study, the reaction selectivities of seven types of Pt supported on carbon (Pt/C) electrocatalysts were evaluated using a porous microelectrode in the presence of methanol and oxygen. As a result, some Pt/C catalysts showed a methanol oxidation selectivity, while the other catalysts showed an oxygen reduction selectivity. It was found that the percentage of edge-atom in the Pt particle is related to the methanol oxidation selectivity or the oxygen reduction selectivity. Moreover, each current density decreases with the increasing chemical shift in the Pt binding energy

  18. Perfil clínico e laboratorial de crianças e adolescentes em uma unidade de hemodiálise: um estudo retrospectivo

    OpenAIRE

    Freitas, Johnathan Santana de

    2013-01-01

    A doença renal crônica (DRC) é definida pela presença de lesão renal e/ou por perda da função renal por um período maior que três meses. No estágio 5 da DRC há sinais de uremia, sendo necessária uma das modalidades de terapia renal substitutiva, dentre elas a hemodiálise. Na criança com DRC é importante identificar e tratar a anemia, complicação frequente e relacionada à diminuição da qualidade de vida (com prejuízos no desenvolvimento neurocognitivo, na atenção escolar e na capacidade física...

  19. Role of peripheral eosinophilia in adverse cutaneous drug reactions.

    Science.gov (United States)

    Drago, F; Cogorno, L; Agnoletti, A F; Parodi, A

    2015-01-01

    The objective of this retrospective study was to verify whether peripheral eosinophilia (PE) may be a marker of severity for adverse cutaneous drug reactions (ACDR). We investigated for PE in sixty-three patients diagnosed as adverse cutaneous drug reactions. All the patients underwent blood tests at baseline visit. Only patients that showed a very likely connection between ACDR and the suspected causative drug were induced in the study. We found that 11 out of 63 patients (17%) presented PE for values ≥ 0.6 x 10(9) cells/l or for a percentage of total leukocytes ≥ 6%. These 11 patients compared to patients without eosinophilia had a longer recovery time, they showed diffuse severe cutaneous reactions and they all needed a systemic therapy compared to the 41% of patients without eosinophilia. These outcomes prompt us to believe that peripheral eosinophilia may be an index of severity for adverse cutaneous drug reactions. Therefore, we suggest physicians to always detect the presence of peripheral eosinophilia in order to not underestimate the reaction and to promptly start an appropriate therapy.

  20. Reaction time for trimolecular reactions in compartment-based reaction-diffusion models

    Science.gov (United States)

    Li, Fei; Chen, Minghan; Erban, Radek; Cao, Yang

    2018-05-01

    Trimolecular reaction models are investigated in the compartment-based (lattice-based) framework for stochastic reaction-diffusion modeling. The formulae for the first collision time and the mean reaction time are derived for the case where three molecules are present in the solution under periodic boundary conditions. For the case of reflecting boundary conditions, similar formulae are obtained using a computer-assisted approach. The accuracy of these formulae is further verified through comparison with numerical results. The presented derivation is based on the first passage time analysis of Montroll [J. Math. Phys. 10, 753 (1969)]. Montroll's results for two-dimensional lattice-based random walks are adapted and applied to compartment-based models of trimolecular reactions, which are studied in one-dimensional or pseudo one-dimensional domains.

  1. 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.

  2. Regulation of cutaneous allergic reaction by odorant inhalation.

    Science.gov (United States)

    Hosoi, J; Tsuchiya, T

    2000-03-01

    Olfactory stimuli modulate emotional conditions and the whole body immune system. Effects of odorant inhalation on cutaneous immune reaction were examined. Contact hypersensitivity to 2,4, 6-trinitrochlorobenzene was elicited in C57BL/6 mice. The reaction was suppressed at both the induction and elicitation phases by exposure to an odorant, citralva. Topical application of citralva or lyral/lilial did not affect the reaction. The suppressive effect of citralva was more potent than that of another odorant, lyral/lilial. Citralva decreased the number of epidermal Langerhans cells, whereas lyral/lilial had a weak effect. Citralva but not lyral/lilial induced plasma corticosterone. Glucocorticoid receptor antagonist abrogated the suppressive effect of citralva on contact hypersensitivity. Serum interleukin-12 was downregulated by exposure to citralva or lyral/lilial. These data demonstrate that olfactory stimuli regulate the cutaneous immune system.

  3. The racial discourse and the Dutch Reformed Church: Looking ...

    African Journals Online (AJOL)

    The aim of this article is to give a descriptive-empirical description of the relationship between the DRC and race by using the Church Mirror surveys. An altered social distance scale is used to measure church acceptance. In the discourse on race, acceptance and unity in the DRC with regard to racial prejudice and attitudes ...

  4. Prevalência de doença renal crônica em adultos atendidos na Estratégia de Saúde da Família

    Directory of Open Access Journals (Sweden)

    Edna Regina Silva Pereira

    2016-03-01

    Full Text Available Resumo Introdução: Doença renal crônica (DRC é um importante problema de saúde pública que, no Brasil, tem como principais etiologias a hipertensão arterial (HA e odiabetes mellitus (DM. O diagnóstico precoce possibilita a implementação de medidas preventivas que retardam ou mesmo interrompem a progressão para os estágios mais avançados da DRC. Objetivo: Identificar a prevalência e os fatores associados à DRC entre adultos atendidos pela Estratégia de Saúde da Família (ESF. Métodos: Estudo transversal com delineamento epidemiológico, descritivo e observacional, realizado com 511 adultos maiores de 20 anos, atendidos na ESF em região de Goiânia, GO. Definiu-se DRC como TFG < 60 mL/min/1,73 m2 e/ou albuminúria ≥ 30 mg/g. A taxa de filtração glomerular (TFG foi estimada pela equação de Cockcroft-Gault e a albuminúria por meio da razão entre albumina e creatinina urinária em amostra de urina. Constituíram variáveis independentes: idade, sexo, pressão arterial, uso de álcool, DM, tabagismo e sobrepeso/obesidade. Resultados: A prevalência de DRC foi 32,53%, enquanto TFG < 60 mL/min/1,73 m2 ocorreu em 10,64% e albuminúria em 25,29% da amostra. A análise identificou associação significativa entre idade ≥ 60 anos e TFG < 60 mL/min/1,73 m2 (p < 0,001. Quanto à albuminúria ≥ 30 mg/g, encontrou-se associação com sexo masculino (p = 0,043, DM (p = 0,002 e consumo de álcool (p = 0,035. Conclusão: Observou-se alta prevalência de DRC nos estágio iniciais na ESF, sendo os fatores associados à doença idade ≥ 60 anos, sexo masculino, DM e consumo de álcool. Logo, sugere-se a realização de triagem e monitoramento para DRC em adultos atendidos na ESF.

  5. Thermal Stability of Li-Ion Cells

    International Nuclear Information System (INIS)

    ROTH, EMANUEL P.

    1999-01-01

    The thermal stability of Li-ion cells with intercalating carbon anodes and metal oxide cathodes was measured as a function of state of charge and temperature for two advanced cell chemistries. Cells of the 18650 design with Li(sub x)CoO(sub 2) cathodes (commercial SONY cells) and Li(sub x)Ni(sub 0.8)Co(sub 0.2)O(sub 2) cathodes were measured for thermal reactivity in the open circuit cell condition. Accelerating rate calorimetry (ARC) was used to measure cell thermal runaway as a function of state of charge (SOC). Microcalorimetry was used to measure the time dependence of heat generating side reactions also as a function of SOC. Components of cells were measured using differential scanning calorimetry (DSC) to study the thermal reactivity of the individual electrodes to determine the temperature regimes and conditions of the major thermal reactions. Thermal decomposition of the SEI layer at the anodes was identified as the initiating source for thermal runaway. The cells with Li(sub x)CoO(sub 2) cathodes showed greater sensitivity to SOC and higher accelerating heating rates than seen for the cells with Li(sub x)Ni(sub 0.8)Co(sub 0.2)O(sub 2)cathodes. Lower temperature reactions starting as low as 40 C were also observed that were SOC dependent but not accelerating. These reactions were also measured in the microcalorimeter and observed to decay over time with a power-law dependence and are believed to result in irreversible capacity loss in the cells

  6. Leukemoid reaction in a patient with acute lymphoblastic leukemia following the

    Directory of Open Access Journals (Sweden)

    Osman Yokuş

    2013-06-01

    Full Text Available The occurrence of persistent neutrophilic leukocytosisabove 50,000 cells/μL for reasons other thanleukemia is defined as leukemoid reaction. Chronicmyelogenous leukemia (CML and chronic neutrophilicleukemia (CNL should be excluded, and underlyingdiseases or causes should be examined,in differential diagnosis. The most commonly observedcauses of leukemoid reactions are severeinfections, intoxications, malignancies, severe hemorrhage,or acute hemolysis [1]. J Clin Exp Invest2013; 4 (2: 258-259

  7. A Continuous-Exchange Cell-Free Protein Synthesis System Based on Extracts from Cultured Insect Cells

    Science.gov (United States)

    Stech, Marlitt; Quast, Robert B.; Sachse, Rita; Schulze, Corina; Wüstenhagen, Doreen A.; Kubick, Stefan

    2014-01-01

    In this study, we present a novel technique for the synthesis of complex prokaryotic and eukaryotic proteins by using a continuous-exchange cell-free (CECF) protein synthesis system based on extracts from cultured insect cells. Our approach consists of two basic elements: First, protein synthesis is performed in insect cell lysates which harbor endogenous microsomal vesicles, enabling a translocation of de novo synthesized target proteins into the lumen of the insect vesicles or, in the case of membrane proteins, their embedding into a natural membrane scaffold. Second, cell-free reactions are performed in a two chamber dialysis device for 48 h. The combination of the eukaryotic cell-free translation system based on insect cell extracts and the CECF translation system results in significantly prolonged reaction life times and increased protein yields compared to conventional batch reactions. In this context, we demonstrate the synthesis of various representative model proteins, among them cytosolic proteins, pharmacological relevant membrane proteins and glycosylated proteins in an endotoxin-free environment. Furthermore, the cell-free system used in this study is well-suited for the synthesis of biologically active tissue-type-plasminogen activator, a complex eukaryotic protein harboring multiple disulfide bonds. PMID:24804975

  8. Severe skin reaction secondary to concomitant radiotherapy plus cetuximab

    International Nuclear Information System (INIS)

    Berger, Bernhard; Belka, Claus

    2008-01-01

    The therapeutic use of monoclonal antibodies against the epidermal growth factor receptor (EGFR) is specifically associated with dermatologic reactions of variable severity. Recent evidence suggests superiority of the EGFR inhibitor (EGFRI) cetuximab plus radiotherapy compared to radiotherapy alone in patients with squamous cell carcinoma of the head and neck. Although not documented in a study population, several reports indicate a possible overlap between radiation dermatitis and the EGFRI-induced skin rash. We here present a case of severe skin reaction secondary to the addition of cetuximab to radiotherapy

  9. Deciphering the Astrocyte Reaction in Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Beatriz G. Perez-Nievas

    2018-04-01

    Full Text Available Reactive astrocytes were identified as a component of senile amyloid plaques in the cortex of Alzheimer’s disease (AD patients several decades ago. However, their role in AD pathophysiology has remained elusive ever since, in part owing to the extrapolation of the literature from primary astrocyte cultures and acute brain injury models to a chronic neurodegenerative scenario. Recent accumulating evidence supports the idea that reactive astrocytes in AD acquire neurotoxic properties, likely due to both a gain of toxic function and a loss of their neurotrophic effects. However, the diversity and complexity of this glial cell is only beginning to be unveiled, anticipating that astrocyte reaction might be heterogeneous as well. Herein we review the evidence from mouse models of AD and human neuropathological studies and attempt to decipher the main conundrums that astrocytes pose to our understanding of AD development and progression. We discuss the morphological features that characterize astrocyte reaction in the AD brain, the consequences of astrocyte reaction for both astrocyte biology and AD pathological hallmarks, and the molecular pathways that have been implicated in this reaction.

  10. Reaction mechanism of O-acylhydroxamate with cysteine proteases

    Indian Academy of Sciences (India)

    WINTEC

    more stable than the reactant and hence the reaction enthalpy is found to be exothermic. ... healing, fertilization, cell differentiation and growth, ... to lower the side effects of drug administration. Since ... tozoa and plants. ... give turnover products or could produce a stable ad- ...... be due to the hydrolysis with water molecule.

  11. Kan die NG Kerk nog �n konstruktiewe rol in die Suid-Afrikaanse samelewing speel?

    Directory of Open Access Journals (Sweden)

    D E de Villiers

    2008-05-01

    Full Text Available The question in the heading is dealt with in the article by splitting it up in three sub-questions: 1. Does the South African society has need for what the DRC can offer? 2. Does the DRC still have the room and opportunity to play a constructive role in our society? and 3. Are the DRC and its members willing and prepared to play such a constructive role in our society? The article arrives at the conclusion that there is indeed need in the South African society for the type of service that the DRC and its high percentage of well-educated, creative and affluent members can provide. Although the opportunity for providing such service has been restricted as a result of the loss of influence on the government and the separation of church and state in the new political dispensation, considerable scope still remains. There is unfortunately an unwillingness among many members to utilise the remaining opportunities for playing a constructive public role, on account of their negative assessment of developments in the new political dispensation and a resulting inward directed spirituality. The DRC would only be able to realise its full potential for playing such a role if a change of heart takes place and the inward directed spirituality is replaced with an outward directed spirituality based on the belief in the centrality of the Kingdom of God in the ministry of the church.

  12. 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.

  13. Individual and household characteristics of persons with Plasmodium falciparum malaria in sites with varying endemicities in Kinshasa Province, Democratic Republic of the Congo.

    Science.gov (United States)

    Mwandagalirwa, Melchior Kashamuka; Levitz, Lauren; Thwai, Kyaw L; Parr, Jonathan B; Goel, Varun; Janko, Mark; Tshefu, Antoinette; Emch, Michael; Meshnick, Steven R; Carrel, Margaret

    2017-11-09

    The Democratic Republic of the Congo (DRC) bears a large share of global malaria burden despite efforts to control and eliminate the disease. More detailed understanding of individual and household level characteristics associated with malaria are needed, as is an understanding of how these characteristics vary spatiotemporally and across different community-level malaria endemicities. An ongoing study in Kinshasa Province is designed to address gaps in prior malaria surveillance in the DRC by monitoring malaria across seasons, age groups and in high and low malaria sites. Across seven sites, 242 households and 1591 individuals are participating in the study. Results of the enrollment questionnaire, rapid diagnostic tests and PCR testing of dried blood spots are presented. Overall malaria prevalence in the study cohort is high, 27% by rapid diagnostic test and 31% by polymerase chain reaction, and malaria prevalence is highly varied across very small geographic distances. Malaria prevalence is highest in children aged 6-15. While the majority of households own bed nets, bed net usage is less than 50%. The study cohort will provide an understanding of how malaria persists in populations that have varying environmental exposures, varying community-level malaria, and varying access to malaria control efforts.

  14. Strengthening laboratory capacity through the surveillance of rotavirus gastroenteritis in Central Africa: the Surveillance Épidémiologique en Afrique Centrale (SURVAC) Project.

    Science.gov (United States)

    Waku-Kouomou, Diane; Esona, Mathew D; Pukuta, Elizabeth; Gouandijka-Vasilache, Ionela; Boula, Angeline; Dahl, Benjamin A; Mondonge, Vital; Mekontso, David; Guifara, Gilbert; Mbary-Daba, Regis; Lewis, Jamie; Yahaya, Ali Ahmed; Mwenda, Jason M; Cavallaro, Kathleen F; Gody, Jean Chrysostome; Muyembe, Jean-Jacques; Koki-Ndombo, Paul; Bowen, Michael D

    2016-01-01

    The goal of the SURVAC pilot project was to strengthen disease surveillance and response in three countries; Cameroon (CAE), Democratic Republic of the Congo (DRC) and Central African Republic (CAR). Seven laboratories involved in rotavirus surveillance were provided with equipment, reagents and supplies. CDC and WHO staff provided on-site classroom and bench training in biosafety, quality assurance, quality control (QC), rotavirus diagnosis using Enzyme Immunoassay (EIA) and genotyping of rotavirus strains using the Reverse Transcription Polymerase-chain reaction (RT-PCR). All laboratory data were reported through WHO/AFRO. Twenty-three staff members were trained on RT-PCR for rotavirus genotyping which was introduced for the first time in all three countries. In CAE, the number of samples analysed by EIA and RT-PCR increased tenfold between 2007 and 2013. In DRC, this number increased fivefold, from 2009 to 2013 whereas in CAR, it increased fourfold between 2011 and 2013. All laboratories passed WHO proficiency testing in 2014. Laboratory capacity was strengthened through equipping laboratories and strengthening a subregional laboratory workforce for surveillance of rotavirus gastroenteritis. Each of the three countries generated rotavirus surveillance and genotyping data enabling the mapping of circulating genotypes. These results will help monitor the impact of rotavirus vaccination in these countries. © 2015 John Wiley & Sons Ltd.

  15. 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.

  16. EU-Verordnung zu "Konfliktmineralien": Ein Schritt zu höherer Rechenschaftspflicht im Rohstoffsektor?

    OpenAIRE

    Küblböck, Karin; Grohs, Hannes

    2017-01-01

    "No blood in my cell phone" - Anfang der 2000er-Jahre zeigten Kampagnen von Nichtregierungsorganisationen (NGOs) Verbindungen zwischen Rohstoffen in Elektronikprodukten und der Finanzierung des Krieges in der Demokratischen Republik Kongo (DRC) auf. In diesem Zusammenhang rückte auch die Verantwortung von Unternehmen für die Gestaltung ihrer Lieferkette verstärkt ins öffentliche Bewusstsein. 2017 tritt nun eine EU-Verordnung in Kraft, die verhindern soll, dass Unternehmen durch ihre Rohstoffb...

  17. Synthesis of Group IVB Metals Oxicarbides by Carboreduction Reactions

    Directory of Open Access Journals (Sweden)

    A.D. Mazzoni

    2002-10-01

    Full Text Available The metals of the group IV B (Ti, Zr, Hf present a series of carbides and oxicarbides with scientific and technological interest. Many of these compounds belong to the subsystem "MO - MC" of the pseudoternary "MO - MN - MC" system (where M = Ti, Zr or Hf. In this work carboreduction reactions of TiO2 and ZrO2 were performed in argon atmosphere, using temperatures from 1250° to 1650° and reaction times of 120 min. The oxicarbides obtained were in the range TiC0.16O0.84 to TiC0.73O0.27 and ZrC0.46O0.54 to ZrC0.90O0.10. respectively. The reaction products were characterized by X-ray diffraction (XRD, with the calculation of their cell constants by means of the Rietveld method. Scanning Electron Microscopy (SEM was used in the characterization of powdered materials. Additionally, the carborreduction reaction was followed by weight loss.

  18. Application of reaction type of C-peptide release test in diabetes mellitus

    International Nuclear Information System (INIS)

    Chen Dong; Duan Wenruo; He Juan; Lu Zhenfang

    2001-01-01

    The author is to confirm the effect of C-peptide release test and types of release reaction in appraisal of pancreas function of β-cell and selection of treatment for diabetes mellitus (DM) patients. The serum C-peptide release test of 67 normal controls and 217 DM patients were determined by RIA, and the results were analyzed and compared. C-peptide release test can reflect the pancreas function of β-cell better, the peak of C-peptide ≥ 0.6 nmol/L after lunch can be the limit of whether to reduce the level of blood glucose only by oral drug. The authors should adjust the treatment through analyzing the type of C-peptide release reaction. C-peptide release test is very important in evaluating the pancreas function of β-cell, classifying the type of DM and selecting the treatment

  19. 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.

  20. 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

  1. 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.

  2. Mast cells enhance T cell activation: Importance of mast cell-derived TNF

    Science.gov (United States)

    Nakae, Susumu; Suto, Hajime; Kakurai, Maki; Sedgwick, Jonathon D.; Tsai, Mindy; Galli, Stephen J.

    2005-05-01

    Mast cells are not only important effector cells in immediate hypersensitivity reactions and immune responses to pathogens but also can contribute to T cell-mediated disorders. However, the mechanisms by which mast cells might influence T cells in such settings are not fully understood. We find that mast cells can enhance proliferation and cytokine production in multiple T cell subsets. Mast cell-dependent enhancement of T cell activation can be promoted by FcRI-dependent mast cell activation, TNF production by both mast cells and T cells, and mast cell-T cell contact. However, at high concentrations of cells, mast cells can promote T cell activation independent of IgE or TNF. Finally, mast cells also can promote T cell activation by means of soluble factors. These findings identify multiple mechanisms by which mast cells can influence T cell proliferation and cytokine production. allergy | asthma | autoimmunity | cytokines | immune response

  3. Reacciones transfusionales mediadas inmunológicamente immunologically mediated transfusional reactions

    Directory of Open Access Journals (Sweden)

    Elkín Ferdinand Cardona Duque

    2001-01-01

    Full Text Available Son muchas las complicaciones potenciales de la terapia transfusional, pero la mayoría se presentan en pacientes que requieren múltiples transfusiones. Los riesgos asociados con la transfusión de una unidad sanguínea son realmente bajos pero deben considerarse contra los beneficios que se buscan al ordenarla. Las reacciones transfusionales se pueden clasificar como inmunológicas y no inmunológicas. Muchas de las primeras son causadas por estimulación de los anticuerpos por parte de los antígenos presentes en la transfusión de glóbulos rojos, leucocitos, plaquetas o proteínas del plasma. Esa isoinmunización puede llevar a una reacción futura cuando dichos antígenos sean transfundidos nuevamente al paciente. Entre las posibilidades se incluyen la hemólisis por incompatibilidad; las reacciones febriles o pulmonares causadas por antígenos en las plaquetas o los leucocitos; los fenómenos alérgicos o anafilácticos debidos a anticuerpos que reaccionan con antígenos solubles, generalmente del tipo de proteínas plasmáticas, y otras de menor importancia. The potential complications of blood transfusion therapy are multiple but most of them occur only in patients requiring repeated transfusions. Risks associated with transfusion of a single unit of blood are low; however, they must be weighted against the benefits at the time each transfusion is ordered. Transfusion reactions can be classified as either immunologic or non-immunologic. Many immune reactions are caused by stimulation of antibody production by foreign alloantigens present on transfused red cells, leukocytes, platelets, or plasma proteins. Such alloimmunization may lead to future immunologically mediated reactions when transfusions carrying these antigens are administered. These include hemolytic reactions caused by red blood cell incompatibility; febrile or pulmonary reactions caused by leukocytes and platelet antigens; allergic or anaphylactic reactions caused by

  4. Radiation treatment and radiation reactions in dermatology. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Panizzon, Renato G. [Univ. Hospital CHUV, Lausanne (Switzerland). Dept. of Dermatology; Seegenschmiedt, M. Heinrich (ed.) [Strahlenzentrum Hamburg (Germany)

    2015-03-01

    Explains the use of radiation treatment in the full range of skin cancers and precancerous lesions. Covers physical and radiobiological principles, dose definitions, radiation reactions, and risk assessments. Revised and updated edition that includes new chapters and numerous additional figures. In this book, leading experts in the dermatological and oncological field describe the use of radiation therapy for the treatment of the full range of dermatological malignancies - including basal cell carcinoma, squamous cell carcinoma, cutaneous lymphomas, Kaposi's sarcoma, melanoma, and Merkel cell tumor - as well as those precancerous lesions and non-malignant dermatological disorders which are amenable to radiation therapy. In each case the specific indications for the use of radiotherapy and its application are clearly explained with the aid of numerous high-quality illustrations. In addition, the book provides a concise introduction to physical and radiobiological principles, selection of radiation factors, dose definitions, radiation reactions, and risk assessments. The new edition has been thoroughly revised and updated to reflect advances in practical knowledge and clinical practice. It will be an invaluable source of information on the management of skin tumors and related non-malignant disorders for both dermatologists, oncologists and radiation oncologists.

  5. Radiation treatment and radiation reactions in dermatology. 2. ed.

    International Nuclear Information System (INIS)

    Panizzon, Renato G.

    2015-01-01

    Explains the use of radiation treatment in the full range of skin cancers and precancerous lesions. Covers physical and radiobiological principles, dose definitions, radiation reactions, and risk assessments. Revised and updated edition that includes new chapters and numerous additional figures. In this book, leading experts in the dermatological and oncological field describe the use of radiation therapy for the treatment of the full range of dermatological malignancies - including basal cell carcinoma, squamous cell carcinoma, cutaneous lymphomas, Kaposi's sarcoma, melanoma, and Merkel cell tumor - as well as those precancerous lesions and non-malignant dermatological disorders which are amenable to radiation therapy. In each case the specific indications for the use of radiotherapy and its application are clearly explained with the aid of numerous high-quality illustrations. In addition, the book provides a concise introduction to physical and radiobiological principles, selection of radiation factors, dose definitions, radiation reactions, and risk assessments. The new edition has been thoroughly revised and updated to reflect advances in practical knowledge and clinical practice. It will be an invaluable source of information on the management of skin tumors and related non-malignant disorders for both dermatologists, oncologists and radiation oncologists.

  6. Aqueous Oxidative Heck Reaction as a Protein-Labeling Strategy

    NARCIS (Netherlands)

    Ourailidou, Marilena; van der Meer, Jan-Ytzen; Baas, Bert-Jan; Jeronimus-Stratingh, Catherine; Gottumukkala, Aditya L.; Poelarends, Gerrit J.; Minnaard, Adriaan J.; Dekker, Frans

    2014-01-01

    An increasing number of chemical reactions are being employed for bio-orthogonal ligation of detection labels to protein-bound functional groups. Several of these strategies, however, are limited in their application to pure proteins and are ineffective in complex biological samples such as cell

  7. Synthesis and electrocatalytic activity towards oxygen reduction reaction of gold-nanostars

    OpenAIRE

    Oyunbileg G; Batnyagt G; Enkhsaruul B; T Takeguchi

    2018-01-01

    The oxygen reduction reaction (ORR) is a characteristic reaction which determines the performance of fuel cells which convert a chemical energy into an electrical energy. Aims of this study are to synthesize Au-based nanostars (AuNSs) and determine their preliminary electro-catalytic activities towards ORR by a rotating-disk electrode method in alkaline electrolyte. The images obtained from a scanning electron microscope (SEM) and a transmission electron microscope (TEM) analyses confirm the ...

  8. Fluorescent Carbon Dots Derived from Maillard Reaction Products: Their Properties, Biodistribution, Cytotoxicity, and Antioxidant Activity.

    Science.gov (United States)

    Li, Dongmei; Na, Xiaokang; Wang, Haitao; Xie, Yisha; Cong, Shuang; Song, Yukun; Xu, Xianbing; Zhu, Bei-Wei; Tan, Mingqian

    2018-02-14

    Food-borne nanoparticles have received great attention because of their unique physicochemical properties and potential health risk. In this study, carbon dots (CDs) formed during one of the most important chemical reactions in the food processing field, the Maillard reaction from the model system including glucose and lysine, were investigated. The CDs purified from Maillard reaction products emitted a strong blue fluorescence under ultraviolet light with a fluorescent quantum yield of 16.30%. In addition, they were roughly spherical, with sizes of around 4.3 nm, and mainly composed of carbon, oxygen, hydrogen, and nitrogen. Their surface groups such as hydroxyl, amino, and carboxyl groups were found to possibly enable CDs to scavenge DPPH and hydroxyl radicals. Furthermore, the cytotoxicity assessment of CDs showed that they could readily enter HepG2 cells while causing negligible cell death at low concentration. However, high CDs concentrations were highly cytotoxic and led to cell death via interference of the glycolytic pathway.

  9. 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.

  10. 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

  11. Reaction Decoder Tool (RDT): extracting features from chemical reactions.

    Science.gov (United States)

    Rahman, Syed Asad; Torrance, Gilliean; Baldacci, Lorenzo; Martínez Cuesta, Sergio; Fenninger, Franz; Gopal, Nimish; Choudhary, Saket; May, John W; Holliday, Gemma L; Steinbeck, Christoph; Thornton, Janet M

    2016-07-01

    Extracting chemical features like Atom-Atom Mapping (AAM), Bond Changes (BCs) and Reaction Centres from biochemical reactions helps us understand the chemical composition of enzymatic reactions. Reaction Decoder is a robust command line tool, which performs this task with high accuracy. It supports standard chemical input/output exchange formats i.e. RXN/SMILES, computes AAM, highlights BCs and creates images of the mapped reaction. This aids in the analysis of metabolic pathways and the ability to perform comparative studies of chemical reactions based on these features. This software is implemented in Java, supported on Windows, Linux and Mac OSX, and freely available at https://github.com/asad/ReactionDecoder : asad@ebi.ac.uk or s9asad@gmail.com. © The Author 2016. Published by Oxford University Press.

  12. Magnetization of individual yeast cells by in situ formation of iron oxide on cell surfaces

    Science.gov (United States)

    Choi, Jinsu; Lee, Hojae; Choi, Insung S.; Yang, Sung Ho

    2017-09-01

    Magnetic functionalization of living cells has intensively been investigated with the aim of various bioapplications such as selective separation, targeting, and localization of the cells by using an external magnetic field. However, the magnetism has not been introduced to individual living cells through the in situ chemical reactions because of harsh conditions required for synthesis of magnetic materials. In this work, magnetic iron oxide was formed on the surface of living cells by optimizing reactions conditions to be mild sufficiently enough to sustain cell viability. Specifically, the reactive LbL strategy led to formation of magnetically responsive yeast cells with iron oxide shells. This facile and direct post-magnetization method would be a useful tool for remote manipulation of living cells with magnetic interactions, which is an important technique for the integration of cell-based circuits and the isolation of cell in microfluidic devices.

  13. Neutral theory of chemical reaction networks

    International Nuclear Information System (INIS)

    Lee, Sang Hoon; Holme, Petter; Minnhagen, Petter; Bernhardsson, Sebastian; Kim, Beom Jun

    2012-01-01

    To what extent do the characteristic features of a chemical reaction network reflect its purpose and function? In general, one argues that correlations between specific features and specific functions are key to understanding a complex structure. However, specific features may sometimes be neutral and uncorrelated with any system-specific purpose, function or causal chain. Such neutral features are caused by chance and randomness. Here we compare two classes of chemical networks: one that has been subjected to biological evolution (the chemical reaction network of metabolism in living cells) and one that has not (the atmospheric planetary chemical reaction networks). Their degree distributions are shown to share the very same neutral system-independent features. The shape of the broad distributions is to a large extent controlled by a single parameter, the network size. From this perspective, there is little difference between atmospheric and metabolic networks; they are just different sizes of the same random assembling network. In other words, the shape of the degree distribution is a neutral characteristic feature and has no functional or evolutionary implications in itself; it is not a matter of life and death. (paper)

  14. 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

  15. Lithium-thionyl chloride cell system safety hazard analysis

    Science.gov (United States)

    Dampier, F. W.

    1985-03-01

    This system safety analysis for the lithium thionyl chloride cell is a critical review of the technical literature pertaining to cell safety and draws conclusions and makes recommendations based on this data. The thermodynamics and kinetics of the electrochemical reactions occurring during discharge are discussed with particular attention given to unstable SOCl2 reduction intermediates. Potentially hazardous reactions between the various cell components and discharge products or impurities that could occur during electrical or thermal abuse are described and the most hazardous conditions and reactions identified. Design factors influencing the safety of Li/SOCl2 cells, shipping and disposal methods and the toxicity of Li/SOCl2 battery components are additional safety issues that are also addressed.

  16. Acute skin reaction after fractionated irradiation

    International Nuclear Information System (INIS)

    Kozubek, S.

    1983-01-01

    Experimental data on acute mouse and pig skin reaction after fractionated γ or X irradiation have been analysed in terms of a new cell tissue kinetic model. The exponential-quadratic and generalized Huggett formulae have been used for cell lethality description. Fairly better results could be demonstrated with generalized Huggett formula. The speed of repopulation has been determined for fractionated regimes as well as for some irregular schedules. The repopulation is slower in the case of fractionated treatment. On considering the normal cell loss factor in the tissue, minimum cell cycle time has been calculated. Its value differs for various strains (Tsub(d)=28.8 hours for SAS/TO mice and Tsub(d) < or approximately 17 hours for WHT/Ht mice) and does not differ for plucked skin. The repopulation has been shown to follow exponential dependence after some latent period. Other factors influencing the effectiveness of radiation treatment (the length of the latent period or the changes of the survival curve during fractionated irradiation) have been considered, too

  17. Reaction paths and rate constants of the reaction of hydroxyl radicals with environmental species under tropospheric conditions

    International Nuclear Information System (INIS)

    Leonard, C.; Wahner, A.; Zetzsch, C.

    1987-01-01

    The uv-laser absorption technique in a multipath cell (with excimer-laser photolysis for radical production) is used to investigate the rate constants of the reaction of OH with carbon monoxide. The pressure dependence and the influence of collision partners (measurements in pure oxygen up to one atmosphere) of this important atmospheric chemical reaction are determined. In the kinetic measurements detection limits of 10 7 OH cm -3 are reached with millisecond time resolution. Furthermore the application of the cw-Laser for stationary OH measurements (for example in smog chambers or the free troposphere) is described. The possibilities and limits of different detection methods are discussed with respect to of noise spectra. Modifications of the apparatus with a frequency modulation technique are presented, with an extrapolated detection limit of 10 5 OH cm -3 . (orig.) With 43 refs., 16 figs [de

  18. Correlation between discrete probability and reaction front propagation rate in heterogeneous mixtures

    Science.gov (United States)

    Naine, Tarun Bharath; Gundawar, Manoj Kumar

    2017-09-01

    We demonstrate a very powerful correlation between the discrete probability of distances of neighboring cells and thermal wave propagation rate, for a system of cells spread on a one-dimensional chain. A gamma distribution is employed to model the distances of neighboring cells. In the absence of an analytical solution and the differences in ignition times of adjacent reaction cells following non-Markovian statistics, invariably the solution for thermal wave propagation rate for a one-dimensional system with randomly distributed cells is obtained by numerical simulations. However, such simulations which are based on Monte-Carlo methods require several iterations of calculations for different realizations of distribution of adjacent cells. For several one-dimensional systems, differing in the value of shaping parameter of the gamma distribution, we show that the average reaction front propagation rates obtained by a discrete probability between two limits, shows excellent agreement with those obtained numerically. With the upper limit at 1.3, the lower limit depends on the non-dimensional ignition temperature. Additionally, this approach also facilitates the prediction of burning limits of heterogeneous thermal mixtures. The proposed method completely eliminates the need for laborious, time intensive numerical calculations where the thermal wave propagation rates can now be calculated based only on macroscopic entity of discrete probability.

  19. Evaluation of the tissue reaction to fast endodontic cement (CER) and Angelus MTA.

    Science.gov (United States)

    Gomes-Filho, João Eduardo; Rodrigues, Guilherme; Watanabe, Simone; Estrada Bernabé, Pedro Felício; Lodi, Carolina Simonett; Gomes, Alessandra Cristina; Faria, Max Doulgas; Domingos Dos Santos, Alailson; Silos Moraes, João Carlos

    2009-10-01

    A new cement (CER; Cimento Endodôntico Rápido or fast endodontic cement) has been developed to improve handling properties. It is a formulation that has Portland cement in gel. However, there had not yet been any study evaluating its biologic properties. The purpose of this study was to evaluate the rat subcutaneous tissue response to CER and Angelus MTA. The materials were placed in polyethylene tubes and implanted into dorsal connective tissue of Wistar rats for 7, 30, and 60 days. The specimens were prepared to be stained with hematoxylin-eosin or von Kossa or not stained for polarized light. The presence of inflammation, predominant cell type, calcification, and thickness of fibrous connective tissue were recorded. Scores were defined as follows: 0, none or few inflammatory cells, no reaction; 1, 125 cells, severe reaction. Fibrous capsule was categorized as thin when thickness was 150 mum. Necrosis and formation of calcification were both recorded. Both materials Angelus MTA and CER caused moderate reactions at 7 days, which decreased with time. The response was similar to the control at 30 and 60 days with Angelus MTA and CER, characterized by organized connective tissue and presence of some chronic inflammatory cells. Mineralization and granulations birefringent to polarized light were observed with both materials. It was possible to conclude that CER was biocompatible and stimulated mineralization.

  20. 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)

  1. Double Displacement: an Improved Bioorthogonal Reaction Strategy for Templated Nucleic Acid Detection

    OpenAIRE

    Kleinbaum, Daniel J.; Miller, Gregory P.; Kool, Eric T.

    2010-01-01

    Quenched autoligation probes have been employed previously in a target-templated nonenzymatic ligation strategy for detecting nucleic acids in cells by fluorescence. A common source of background signal in such probes is undesired reaction with water and other cellular nucleophiles. Here we describe a new class of self-ligating probes, double displacement (DD) probes, that rely on two displacement reactions to fully unquench a nearby fluorophore. Three potential double displacement architectu...

  2. Extent of reaction in open systems with multiple heterogeneous reactions

    Science.gov (United States)

    Friedly, John C.

    1991-01-01

    The familiar batch concept of extent of reaction is reexamined for systems of reactions occurring in open systems. Because species concentrations change as a result of transport processes as well as reactions in open systems, the extent of reaction has been less useful in practice in these applications. It is shown that by defining the extent of the equivalent batch reaction and a second contribution to the extent of reaction due to the transport processes, it is possible to treat the description of the dynamics of flow through porous media accompanied by many chemical reactions in a uniform, concise manner. This approach tends to isolate the reaction terms among themselves and away from the model partial differential equations, thereby enabling treatment of large problems involving both equilibrium and kinetically controlled reactions. Implications on the number of coupled partial differential equations necessary to be solved and on numerical algorithms for solving such problems are discussed. Examples provided illustrate the theory applied to solute transport in groundwater flow.

  3. ReactionMap: an efficient atom-mapping algorithm for chemical reactions.

    Science.gov (United States)

    Fooshee, David; Andronico, Alessio; Baldi, Pierre

    2013-11-25

    Large databases of chemical reactions provide new data-mining opportunities and challenges. Key challenges result from the imperfect quality of the data and the fact that many of these reactions are not properly balanced or atom-mapped. Here, we describe ReactionMap, an efficient atom-mapping algorithm. Our approach uses a combination of maximum common chemical subgraph search and minimization of an assignment cost function derived empirically from training data. We use a set of over 259,000 balanced atom-mapped reactions from the SPRESI commercial database to train the system, and we validate it on random sets of 1000 and 17,996 reactions sampled from this pool. These large test sets represent a broad range of chemical reaction types, and ReactionMap correctly maps about 99% of the atoms and about 96% of the reactions, with a mean time per mapping of 2 s. Most correctly mapped reactions are mapped with high confidence. Mapping accuracy compares favorably with ChemAxon's AutoMapper, versions 5 and 6.1, and the DREAM Web tool. These approaches correctly map 60.7%, 86.5%, and 90.3% of the reactions, respectively, on the same data set. A ReactionMap server is available on the ChemDB Web portal at http://cdb.ics.uci.edu .

  4. 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.

  5. GENERATION OF CYTOTOXIC LYMPHOCYTES IN MIXED LYMPHOCYTE REACTIONS

    Science.gov (United States)

    Forman, James; Möller, Göran

    1973-01-01

    Generation of cytotoxic effector cells by a unidirectional mixed lymphocyte reaction (MLR) in the mouse H-2 system was studied using labeled YAC (H-2a) leukemia cells as targets. The responding effector cell displayed a specific cytotoxic effect against target cells of the same H-2 genotype as the stimulating cell population. Killing of syngeneic H-2 cells was not observed, even when the labeled target cells were "innocent bystanders" in cultures where specific target cells were reintroduced. Similar results were found with spleen cells taken from mice sensitized in vivo 7 days earlier. The effector cell was not an adherent cell and was not activated by supernatants from MLR. The supernatants were not cytotoxic by themselves. When concanavalin A or phytohemagglutinin was added to the cytotoxic test system, target and effector cells were agglutinated. Under these conditions, killing of H-2a target cells was observed in mixed cultures where H-2a lymphocytes were also the effector cells. These findings indicate that specifically activated, probably thymus-derived lymphocytes, can kill nonspecifically once they have been activated and providing there is close contact between effector and target cells. Thus, specificity of T cell killing appears to be restricted to recognition and subsequent binding to the targets, the actual effector phase being nonspecific. PMID:4269560

  6. Mapping Biomass for REDD in the Largest Forest of Central Africa: the Democratic Republic of Congo

    Science.gov (United States)

    Shapiro, Aurelie; Saatchi, Sassan

    2014-05-01

    With the support of the International Climate Initiative (ICI) of the Federal Ministry of the Environment, Conservation, and Nuclear Security, the implementation of the German Development Bank KfW, the World Wide Fund for Nature (WWF) Germany, the University of California Los Angeles (UCLA) and local DRC partners will produce a national scale biomass map for the entire forest coverage of the Democratic Republic of Congo (DRC) along with feasibility assessments of different forest protection measures within a framework of a REDD+ model project. The « Carbon Map and Model (CO2M&M) » project will produce a national forest biomass map for the DRC, which will enable quantitative assessments of carbon stocks and emissions in the largest forest of the Congo Basin. This effort will support the national REDD (Reducing Emissions from Deforestation and Degradation) program in DRC, which plays a major role in sustainable development and poverty alleviation. This map will be developed from field data, complemented by airborne LiDAR (Light Detection and Ranging) and aerial photos, systematically sampled throughout the forests of the DRC and up-scaled to satellite images to accurately estimate carbon content in all forested areas. The second component of the project is to develop specific approaches for model REDD projects in key landscapes. This project represents the largest LiDAR-derived mapping effort in Africa, under unprecedented logistical constraints, which will provide one of the poorest nations in the world with the richest airborne and satellites derived datasets for analyzing forest structure, biomass and biodiversity.

  7. Annual Threat Assessment of the US Intelligence Community for the Senate Select Committee on Intelligence

    Science.gov (United States)

    2010-02-02

    uncertainty and partial diplomatic isolation resulting from the forcible removal of President Manuel Zelaya from power last June. Newly elected...situation in the Democratic Republic of the Congo (DRC) in the year ahead will remain particularly difficult and resistant to resolution. Despite...recent setbacks for some rebel forces in Eastern Congo and improved relations between the DRC and Rwanda, the eastern Congo remains a regional

  8. Threat Assessment of the US Intelligence Community for the Senate Select Committee on Intelligence

    Science.gov (United States)

    2010-02-02

    isolation resulting from the forcible removal of President Manuel Zelaya from power last June. Newly elected President Porfirio Lobo will have to...Democratic Republic of the Congo (DRC) in the year ahead will remain particularly difficult and resistant to resolution. Despite recent setbacks for...some rebel forces in Eastern Congo and improved relations between the DRC and Rwanda, the eastern Congo remains a regional political, security, and

  9. 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.

  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. 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.

  12. 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.

  13. Force, reaction time, and precision of Kung Fu strikes.

    Science.gov (United States)

    Neto, Osmar Pinto; Bolander, Richard; Pacheco, Marcos Tadeu Tavares; Bir, Cynthia

    2009-08-01

    The goal was to compare values of force, precision, and reaction time of several martial arts punches and palm strikes performed by advanced and intermediate Kung Fu practitioners, both men and women. 13 Kung Fu practitioners, 10 men and three women, participated. Only the men, three advanced and seven intermediate, were considered for comparisons between levels. Reaction time values were obtained using two high speed cameras that recorded each strike at 2500 Hz. Force of impact was measured by a load cell. For comparisons of groups, force data were normalized by participant's body mass and height. Precision of the strikes was determined by a high speed pressure sensor. The results show that palm strikes were stronger than punches. Women in the study presented, on average, lower values of reaction time and force but higher values of precision than men. Advanced participants presented higher forces than intermediate participants. Significant negative correlations between the values of force and precision and the values of force and reaction time were also found.

  14. Double displacement: An improved bioorthogonal reaction strategy for templated nucleic acid detection.

    Science.gov (United States)

    Kleinbaum, Daniel J; Miller, Gregory P; Kool, Eric T

    2010-06-16

    Quenched autoligation probes have been employed previously in a target-templated nonenzymatic ligation strategy for detecting nucleic acids in cells by fluorescence. A common source of background signal in such probes is the undesired reaction with water and other cellular nucleophiles. Here, we describe a new class of self-ligating probes, double displacement (DD) probes, that rely on two displacement reactions to fully unquench a nearby fluorophore. Three potential double displacement architectures, all possessing two fluorescence quencher/leaving groups (dabsylate groups), were synthesized and evaluated for templated reaction with nucleophile (phosphorothioate) probes both in vitro and in intact bacterial cells. All three DD probe designs provided substantially better initial quenching than a single-Dabsyl control. In isothermal templated reactions in vitro, double displacement probes yielded considerably lower background signal than previous single displacement probes; investigation into the mechanism revealed that one dabsylate acts as a sacrificial leaving group, reacting nonspecifically with water, but yielding little signal because another quencher group remains. Templated reaction with the specific nucleophile probe is required to activate a signal. The double displacement probes provided a ca. 80-fold turn-on signal and yielded a 2-4-fold improvement in signal/background over single Dabsyl probes. The best-performing probe architecture was demonstrated in a two-color, FRET-based two-allele discrimination system in vitro and was shown to be capable of discriminating between two closely related species of bacteria differing by a single nucleotide at an rRNA target site.

  15. 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...

  16. RhoA/ROCK Signaling Pathway Mediates Shuanghuanglian Injection-Induced Pseudo-allergic Reactions.

    Science.gov (United States)

    Han, Jiayin; Zhao, Yong; Zhang, Yushi; Li, Chunying; Yi, Yan; Pan, Chen; Tian, Jingzhuo; Yang, Yifei; Cui, Hongyu; Wang, Lianmei; Liu, Suyan; Liu, Jing; Deng, Nuo; Liang, Aihua

    2018-01-01

    Background: Shuanghuanglian injection (SHLI) is a famous Chinese medicine used as an intravenous preparation for the treatment of acute respiratory tract infections. In the recent years, the immediate hypersensitivity reactions induced by SHLI have attracted broad attention. However, the mechanism involved in these reactions has not yet been elucidated. The present study aims to explore the characteristics of the immediate hypersensitivity reactions induced by SHLI and deciphers the role of the RhoA/ROCK signaling pathway in these reactions. Methods: SHLI-immunized mice or naive mice were intravenously injected (i.v.) with SHLI (600 mg/kg) once, and vascular leakage in the ears was evaluated. Passive cutaneous anaphylaxis test was conducted using sera collected from SHLI-immunized mice. Naive mice were administered (i.v.) with a single dose of 150, 300, or 600 mg/kg of SHLI, and vascular leakage, histamine release, and histopathological alterations in the ears, lungs, and intestines were tested. In vitro , human umbilical vein endothelial cell (HUVEC) monolayer was incubated with SHLI (0.05, 0.1, or 0.15 mg/mL), and the changes in endothelial permeability and cytoskeleton were observed. Western blot analysis was performed and ROCK inhibitor was employed to investigate the contribution of the RhoA/ROCK signaling pathway in SHLI-induced hypersensitivity reactions, both in HUVECs and in mice. Results: Our results indicate that SHLI was able to cause immediate dose-dependent vascular leakage, edema, and exudates in the ears, lungs, and intestines, and histamine release in mice. These were pseudo-allergic reactions, as SHLI-specific IgE was not elicited during sensitization. In addition, SHLI induced reorganization of actin cytoskeleton and disrupted the endothelial barrier. The administration of SHLI directly activated the RhoA/ROCK signaling pathway both in HUVECs and in the ears, lungs, and intestines of mice. Fasudil hydrochloride, a ROCK inhibitor, ameliorated the

  17. 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.

  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. Effects of radio sensitizers in the vulcanization of natural rubber latex induced by gamma radiation

    International Nuclear Information System (INIS)

    Souza, A. de; Canavel, V.; Araujo, S.C. de; Guedes, S.M.L.

    1992-01-01

    The effect of C Cl 4 and n-butyl acrylate as a sensitizer for radiation vulcanization of 60% DRC natural rubber latex with gamma rays, was studied relating tensile strength of vulcanized latex. The vulcanization dose is 200 kGy for natural rubber latex and it decreases to 40 kGy and to 9 kGy in the presence of C Cl 4 / potassium laureate and n-butyl acrylate / t-butyl hydroperoxide, respectively. The H 2 O 2 as a co-sensitizer does not change the efficiency of the combination of these sensitizers. The IV spectra show the formation of C=O after the irradiation as consequence of oxidation reactions. (author)

  20. Understanding the Oxygen Reduction Reaction on a Y/Pt(111) Single Crystal

    DEFF Research Database (Denmark)

    Ulrikkeholm, Elisabeth Therese; Johansson, Tobias Peter; Malacrida, Paolo

    2014-01-01

    Polymer electrolyte membrane fuel cells (PEMFC) hold promise as a zero-emission source of power, particularly suitable for automotive vehicles. However, the high loading of Pt required to catalyse the oxygen reduction reaction (ORR) at the PEMFC cathode, prevents the commercialisation of this tec......Polymer electrolyte membrane fuel cells (PEMFC) hold promise as a zero-emission source of power, particularly suitable for automotive vehicles. However, the high loading of Pt required to catalyse the oxygen reduction reaction (ORR) at the PEMFC cathode, prevents the commercialisation...... using electrochemical measurements, low energy electron diffraction, ion scattering spectroscopy, angle resolved X-ray photoelectron spectroscopy, temperature programmed desorption of CO, and synchrotron based X-ray absorption spectroscopy and surface sensitive X-ray diffraction. These measurements were...

  1. Kynurenine pathway metabolites and enzymes involved in redox reactions.

    Science.gov (United States)

    González Esquivel, D; Ramírez-Ortega, D; Pineda, B; Castro, N; Ríos, C; Pérez de la Cruz, V

    2017-01-01

    Oxido-reduction reactions are a fundamental part of the life due to support many vital biological processes as cellular respiration and glucose oxidation. In the redox reactions, one substance transfers one or more electrons to another substance. An important electron carrier is the coenzyme NAD + , which is involved in many metabolic pathways. De novo biosynthesis of NAD + is through the kynurenine pathway, the major route of tryptophan catabolism, which is sensitive to redox environment and produces metabolites with redox capacity, able to alter biological functions that are controlled by redox-responsive signaling pathways. Kynurenine pathway metabolites have been implicated in the physiology process and in the physiopathology of many diseases; processes that also share others factors as dysregulation of calcium homeostasis, mitochondrial dysfunction, oxidative stress, inflammation and cell death, which impact the redox environment. This review examines in detail the available evidence in which kynurenine pathway metabolites participate in redox reactions and their effect on cellular redox homeostasis, since the knowledge of the main factors and mechanisms that lead to cell death in many neurodegenative disorders and other pathologies, such as mitochondrial dysfunction, oxidative stress and kynurenines imbalance, will allow to develop therapies using them as targets. This article is part of the Special Issue entitled 'The Kynurenine Pathway in Health and Disease'. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Changes in subcellular elemental distributions accompanying the acrosome reaction in sea urchin sperm

    International Nuclear Information System (INIS)

    Cantino, M.E.; Schackmann, R.W.; Johnson, D.E.

    1983-01-01

    Energy-dispersive x-ray microanalysis was used to analyze changes in the subcellular distributions of Na, Mg, P, S, Cl, K, and Ca associated with the acrosome reaction of sea urchin sperm. Within 5 sec after induction of the acrosome reaction, nuclear Na and mitochondrial Ca increased and nuclear and mitochondrial K decreased. Uptake of mitochondrial P was detected after several minutes, and increases in nuclear Mg were detected only after 5-10 min of incubation following induction of the reaction. The results suggest that sudden permeability changes in the sperm plasma membrane are associated with the acrosome reaction, but that complete breakdown of membrane and cell function does not occur for several minutes

  3. Reaction of the (111) faces of single-crystal indium phosphide with alkylating agents: evidence for selective reaction of the p-rich face

    Energy Technology Data Exchange (ETDEWEB)

    Spool, A.M.; Daube, K.A.; Mallouk, T.E.; Belmont, J.A.; Wrighton, M.S.

    1986-05-28

    We wish to report that the P-rich, (111)B, face of single-crystal InP, but not the In-rich, (111)A, face of the same crystal, reacts with molecular reagents to yield surface-bound material derived from the apparent alkylation of a surface P atom. Exploitation of surface functional groups has been demonstrated to be very important in the attachment of molecular reagents and polymers to electrode surfaces. Electrodes derivatized with molecules have potential uses in analysis, fuel cells, electrosynthetic cells, and photoelectrochemical cells. We now wish to present evidence showing that an important photoelectrode material, InP, can be functionalized with molecules by reaction of the P-rich, (111)B, face with alkylating reagents.

  4. Increase of rutin antioxidant activity by generating Maillard reaction products with lysine.

    Science.gov (United States)

    Zhang, Ru; Zhang, Bian-Ling; He, Ting; Yi, Ting; Yang, Ji-Ping; He, Bin

    2016-06-01

    Rutin exists in medicinal herbs, fruits, vegetables, and a number of plant-derived sources. Dietary sources containing rutin are considered beneficial because of their potential protective roles in multiple diseases related to oxidative stresses. In the present study, the change and antioxidation activity of rutin in Maillard reaction with lysine through a heating process were investigated. There is release of glucose and rhamnose that interact with lysine to give Maillard reaction products (MRPs), while rutin is converted to less-polar quercetin and a small quantity of isoquercitrin. Because of their high cell-membrane permeability, the rutin-lysine MRPs increase the free radical-scavenging activity in HepG2 cells, showing cellular antioxidant activity against Cu(2+)-induced oxidative stress higher than that of rutin. Furthermore, the MRPs significantly increased the Cu/Zn SOD (superoxide dismutase) activity and Cu/Zn SOD gene expression of HepG2 cells, consequently enhancing antioxidation activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. 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.

  6. Expression of antibacterial resistance at the site of a delayed hypersensitivity reaction.

    OpenAIRE

    Patel, P J

    1980-01-01

    The site of a delayed hypersensitivity reaction to tuberculin or bovine serum ablumin was shown to contain mechanisms that expressed increased antibacterial activity, as evidenced by restricted growth of a local inoculum of Listeria monocytogenes. As was the case with a delayed hypersensitivity reaction, the local generation of antibacterial activity was antigen specific and T-cell dependent. Antibacterial resistance was always expressed at the site of injection of specific antigen in sensiti...

  7. Methanol Fuel Cell

    Science.gov (United States)

    Voecks, G. E.

    1985-01-01

    In proposed fuel-cell system, methanol converted to hydrogen in two places. External fuel processor converts only part of methanol. Remaining methanol converted in fuel cell itself, in reaction at anode. As result, size of fuel processor reduced, system efficiency increased, and cost lowered.

  8. Tribological wear behavior of diamond reinforced composite coating

    International Nuclear Information System (INIS)

    Venkateswarlu, K.; Ray, Ajoy Kumar; Gunjan, Manoj Kumar; Mondal, D.P.; Pathak, L.C.

    2006-01-01

    In the present study, diamond reinforced composite (DRC) coating has been applied on mild steel substrate using thermal spray coating technique. The composite powder consists of diamond, tungsten carbide, and bronze, which was mixed in a ball mill prior deposition by thermal spray. The microstructure and the distribution of diamond and tungsten carbide particle in the bronze matrix were studied. The DRC-coated mild steel substrates were assessed in terms of their high stress abrasive wear and compared with that of uncoated mild steel substrates. It was observed that when sliding against steel, the DRC-coated sample initially gains weight, but then loses the transferred counter surface material. In case of abrasive wear, the wear rate was greatly reduced due to the coating; wherein the wear rate decreased with increase in diamond content

  9. Efeito do exercício resistido intradialítico em pacientes renais crônicos em hemodiálise Effect of resistance exercise intradialytic in renal patients chronic in hemodialysis

    Directory of Open Access Journals (Sweden)

    Ronaldo Ribeiro

    2013-03-01

    Full Text Available INTRODUÇÃO: Pacientes com doença renal crônica (DRC quando submetidos ao exercício resistido (ER apresentam substancial melhorias de muitas funções, em especial os relacionados ao sistema cardiovascular, respiratório, muscular e na qualidade de vida (QV. Não existem avaliações do impacto de exercício simples e factíveis em pacientes com DRC associada ao Diabetes Mellitus (DM durante o período intradialítico. OBJETIVO: Estudar o papel do exercício resistido no tratamento e na qualidade de vida em pacientes submetidos à hemodiálise crônica (HD. Assim, submetemos pacientes com DRC e DM ao ER durante a hemodiálise. MÉTODOS: Quinze pacientes em cada grupo: 1: DM com DRC submetidos ao ER; 2: DM com DRC sedentários; 3: DRC e ER e, 4: DRC sedentários. Avaliações durante oito semanas, com ER três vezes na semana. Avaliação laboratorial, teste de força muscular (FM e QV (SF-36. RESULTADOS: O ER induziu melhoria na glicemia e na FM com discretas, mas significantes alterações na uréia e, K (p INTRODUCTION: Patients with chronic kidney disease (CKD when subjected to resistance exercise (RE show substantial improvements in many functions, especially those related to the cardiovascular system, respiratory, muscular and quality of life (QOL. There are no evaluations of the impact of exercise simple and feasible in patients with CKD associated with Diabetes Mellitus (DM during the intradialytic period. Thus, patients with CKD and submit to the DM + RE during hemodialysis. OBJECTIVE: To study the role of resistance exercise in the treatment and quality of life in patients undergoing chronic hemodialysis (HD. METHODS: 15 patients in each group: 1: DM with CKD and RE; 2: DM + CKD sedentary; 3: CKD + RE and 4: DRC sedentary. They were evaluated during eight weeks, with RE three times a week. Parameters: Laboratory assessments, muscle strength testing (FM and QV (SF-36. RESULTS: RE induced improvement in glucose and FM with subtle but

  10. Physiological environment induce quick response - slow exhaustion reactions

    Directory of Open Access Journals (Sweden)

    Noriko eHiroi

    2011-09-01

    Full Text Available In vivo environments are highly crowded and inhomogeneous, which may affect reaction processes in cells. In this study we examined the effects of intracellular crowding and an inhomogeneity on the behavior of in vivo reactions by calculating the spectral dimension (ds, which can be translated into the reaction rate function. We compared estimates of anomaly parameters obtained from Fluorescence Correlation Spectroscopy (FCS data with fractal dimensions derived from Transmission Electron Microscopy (TEM image analysis. FCS analysis indicated that the anomalous property was linked to physiological structure. Subsequent TEM analysis provided an in vivo illustration; soluble molecules likely percolate between intracellular clusters, which are constructed in a self-organizing manner. We estimated a cytoplasmic spectral dimension ds to be 1.39 ± 0.084. This result suggests that in vivo reactions initially run faster than the same reactions in a homogeneous space; this conclusion is consistent with the anomalous character indicated by FCS analysis. We further showed that these results were compatible with our Monte-Carlo simulation in which the anomalous behavior of mobile molecules correlates with the intracellular environment, leading to description as a percolation cluster, as demonstrated using TEM analysis. We confirmed by the simulation that the above-mentioned in vivo like properties are different from those of homogeneously concentrated environments. Additionally, simulation results indicated that crowding level of an environment might affect diffusion rate of reactant. Such knowledge of the spatial information enables us to construct realistic models for in vivo diffusion and reaction systems.

  11. Heterogeneity of ductular reactions in adult rat and human liver revealed by novel expression of deleted in malignant brain tumor 1

    DEFF Research Database (Denmark)

    Bisgaard, H.C.; Holmskov, U.; Santoni-Rugiu, E.

    2002-01-01

    The regenerative capacity of mammalian adult liver reflects the ability of a number of cell populations within the hepatic lineage to take action. Limited information is available regarding factors and mechanisms that determine the specific lineage level at which liver cells contribute to liver......), were specifically associated with the emergence of ductular (oval) cell populations in injured liver. Subsequent cloning and characterization of the rat DMBT1 homologue revealed a highly inducible expression in ductular reactions composed of transit-amplifying ductular (oval) cells, but not in ductular...... reactions after ligation of the common bile duct. In human liver diseases, DMBT1 was expressed in ductular reactions after infection with hepatitis B and acetaminophen intoxication, but not in primary biliary cirrhosis, primary sclerosing cholangitis, and obstruction of the large bile duct. The expression...

  12. Interaction between heavy metals and thiol-linked redox reactions in germination.

    Science.gov (United States)

    Smiri, M; Chaoui, A; Ferjani, E E

    2010-09-15

    Thioredoxin (TRX) proteins perform important biological functions in cells by changing the redox state of proteins via dithiol disulfide exchange. Several systems are able to control the activity, stability, and correct folding of enzymes through dithiol/disulfide isomerization reactions including the enzyme protein disulfide-isomerase, the glutathione-dependent glutaredoxin system, and the thioredoxin systems. Plants have devised sophisticated mechanisms to cope with biotic and abiotic stresses imposed by their environment. Among these mechanisms, those collectively referred to as redox reactions induced by endogenous systems. This is of agronomical importance since a better knowledge of the involved mechanisms can offer novel means for crop protection. In the plant life cycle, the seed and seedling stages are key developmental stages conditioning the final yield of crops. Both are very sensitive to heavy metal stress. Plant redox reactions are principally studied on adult plant organs and there is only very scarce informations about the onset of redox regulation at the level of seed germination. In the here presented study, we discussed the importance of redox proteins in plant cell metabolism and defence. Special focus is given to TRX, which are involved in detoxification of ROS and also to their targets.

  13. Reaction path analysis of sodium-water reaction phenomena in support of chemical reaction model development

    International Nuclear Information System (INIS)

    Kikuchi, Shin; Ohshima, Hiroyuki; Hashimoto, Kenro

    2011-01-01

    Computational study of the sodium-water reaction at the gas (water) - liquid (sodium) interface has been carried out using ab initio (first-principle) method. A possible reaction channel has been identified for the stepwise OH bond dissociations of a single water molecule. The energetics including the binding energy of a water molecule to the sodium surface, the activation energies of the bond cleavages, and the reaction energies, have been evaluated, and the rate constants of the first and second OH bond-breakings have been compared. The results are used as the basis for constructing the chemical reaction model used in a multi-dimensional sodium-water reaction code, SERAPHIM, being developed by JAEA toward the safety assessment of the steam generator (SG) in a sodium-cooled fast reactor (SFR). (author)

  14. Reclassifying Anaphylaxis to Neuromuscular Blocking Agents Based on the Presumed Patho-Mechanism: IgE-Mediated, Pharmacological Adverse Reaction or “Innate Hypersensitivity”?

    Directory of Open Access Journals (Sweden)

    David Spoerl

    2017-06-01

    Full Text Available Approximately 60% of perioperative anaphylactic reactions are thought to be immunoglobulin IgE mediated, whereas 40% are thought to be non-IgE mediated hypersensitivity reactions (both considered non-dose-related type B adverse drug reactions. In both cases, symptoms are elicited by mast cell degranulation. Also, pharmacological reactions to drugs (type A, dose-related may sometimes mimic symptoms triggered by mast cell degranulation. In case of hypotension, bronchospasm, or urticarial rash due to mast cell degranulation, identification of the responsible mechanism is complicated. However, determination of the type of the underlying adverse drug reaction is of paramount interest for the decision of whether the culprit drug may be re-administered. Neuromuscular blocking agents (NMBA are among the most frequent cause of perioperative anaphylaxis. Recently, it has been shown that NMBA may activate mast cells independently from IgE antibodies via the human Mas-related G-protein-coupled receptor member X2 (MRGPRX2. In light of this new insight into the patho-mechanism of pseudo-allergic adverse drug reactions, in which as drug-receptor interaction results in anaphylaxis like symptoms, we critically reviewed the literature on NMBA-induced perioperative anaphylaxis. We challenge the dogma that NMBA mainly cause IgE-mediated anaphylaxis via an IgE-mediated mechanism, which is based on studies that consider positive skin test to be specific for IgE-mediated hypersensitivity. Finally, we discuss the question whether MRGPRX2 mediated pseudo-allergic reactions should be re-classified as type A adverse reactions.

  15. 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.

  16. Comparison of rat connective tissue reaction to two types of foreign and Iranian white Mineral Trioxide Aggregate

    Directory of Open Access Journals (Sweden)

    Vosough Hosseini S.

    2008-11-01

    Full Text Available "nBackground and Aim: Three Dimensional obturation of root canal is one of the main goals of root canal therapy to preserve health or reach the regeneration or healing of periapical tissues. Root end filling materials are used in numerous situations to reach the mentioned goals. One of the common root end- filling materials is mineral trioxide aggregate (MTA which the foreign and Iranian ones are different in their prices. The aim of this study was to compare the rat connective tissue reaction to Iranian and foreign MTA. "nMaterials and Methods: This was an animal study in which 40 rats were divided into 5 groups of each 8. The polyethylene tubes filled with foreign (Pro Root MTA and Iranian (Root MTA white MTA and were implanted in subcutaneous connective tissue. Similarly, the empty tubes were inserted in subcutaneous connective tissue as control group. The samples were examined histologically after 7, 14, 30, 60 and 90 days and were scored as followings: 0, was characterized to samples without inflammatory cells; without inflammatory reaction 1, for samples with less than 25 inflammatory cells; mild inflammatory reaction. 2, for samples with 25 to 125 inflammatory cells; moderate inflammatory reaction and 3, for ones with more than 125 inflammatory cells; severe inflammatory reaction. The data were analyzed using Kruskal-Wallis test and p<0.05 was considered as the level of significance. "nResults: In general, inflammatory reactions were reduced in all groups. Experimental groups had moderate to severe inflammation in the 7th day which had significant difference with the control group having mild to moderate inflammation (p=0.04. There was not any significant differences between experimental and control group in 14th, 30th, 60th and 90th days (p>0.05. "nConclusion: Based on the findings of this investigation, inflammatory subcutaneous connective tissue reaction to Iranian (Root MTA and foreign (Pro Root MTA MTA was the same.

  17. [Development of a Fluorescence Probe for Live Cell Imaging].

    Science.gov (United States)

    Shibata, Aya

    2017-01-01

     Probes that detect specific biological materials are indispensable tools for deepening our understanding of various cellular phenomena. In live cell imaging, the probe must emit fluorescence only when a specific substance is detected. In this paper, we introduce a new probe we developed for live cell imaging. Glutathione S-transferase (GST) activity is higher in tumor cells than in normal cells and is involved in the development of resistance to various anticancer drugs. We previously reported the development of a general strategy for the synthesis of probes for detection of GST enzymes, including fluorogenic, bioluminogenic, and 19 F-NMR probes. Arylsulfonyl groups were used as caging groups during probe design. The fluorogenic probes were successfully used to quantitate very low levels of GST activity in cell extracts and were also successfully applied to the imaging of microsomal MGST1 activity in living cells. The bioluminogenic and 19 F-NMR probes were able to detect GST activity in Escherichia coli cells. Oligonucleotide-templated reactions are powerful tools for nucleic acid sensing. This strategy exploits the target strand as a template for two functionalized probes and provides a simple molecular mechanism for multiple turnover reactions. We developed a nucleophilic aromatic substitution reaction-triggered fluorescent probe. The probe completed its reaction within 30 s of initiation and amplified the fluorescence signal from 0.5 pM target oligonucleotide by 1500 fold under isothermal conditions. Additionally, we applied the oligonucleotide-templated reaction for molecular releasing and peptide detection.

  18. Effect of dual task activity on reaction time in males and females.

    Science.gov (United States)

    Kaur, Manjinder; Nagpal, Sangeeta; Singh, Harpreet; Suhalka, M L

    2014-01-01

    The present study was designed to compare the auditory and visual reaction time on an Audiovisual Reaction Time Machine with the concomitant use of mobile phones in 52 women and 30 men in the age group of 18-40 years. Males showed significantly (p multitasking, in hand held (24.38% & 18.70% respectively) and hands free modes (36.40% & 18.40% respectively) of the use of cell phone. VRT increased non significantly during multitasking in both the groups. However, the multitasking per se has detrimental effect on the reaction times in both the groups studied. Hence, it should best be avoided in crucial and high attention demanding tasks like driving.

  19. Kinetics of the Reaction of CO2 with Aqueous Potassium Salt of Taurine and Glycine

    NARCIS (Netherlands)

    Kumar, P.S.; Hogendoorn, J.A.; Versteeg, G.F.; Feron, P.H.M.

    2003-01-01

    The kinetics of the reaction between CO2 and aqueous potassium salts of taurine and glycine was measured at 295 K in a stirred-cell reactor with a flat gas–liquid interface. For aqueous potassium taurate solutions, the temperature effect on the reaction kinetics was measured at 285 and 305 K. Unlike

  20. Kinetics of the reaction of CO2 with aqueous potassium salt of taurine and glycine

    NARCIS (Netherlands)

    Kumar Paramasivam Senthil, P.S.; Hogendoorn, Kees; Versteeg, Geert; Feron, P.H.M.

    2003-01-01

    The kinetics of the reaction between CO2 and aqueous potassium salts of taurine and glycine was measured at 295 K in a stirred-cell reactor with a flat gas-liquid interface. For aqueous potassium taurate solutions, the temperature effect on the reaction kinetics was measured at 285 and 305 K. Unlike

  1. 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)

  2. Studies in the reaction dynamics of beam-gas chemiluminescent reactions

    International Nuclear Information System (INIS)

    Prisant, M.G.

    1984-01-01

    This thesis develops techniques for the analysis and interpretation of data obtained from beam-gas chemiluminescence experiments. These techniques are applied to experimental studies of atom transfer reactions of the type A + BC → AB + C. A procedure is developed for determining the product rotational alignment in the center-of-mass frame from polarization measurements of chemiluminescent atom-diatom exchange reactions under beam-gas conditions. Knowledge of a vector property of a reaction, such as product alignment, provides information on the disposition of angular momentum by a chemical reaction. Fluorescence polarization and hence product alignment are measured for two prototype reactions. The reaction of metastable calcium atoms with hydrogen-chloride gas yields highly aligned calcium-chloride product which exhibits little variation of alignment with vibrational state. The reaction of ground-state calcium with fluorine gas yields moderately aligned product which shows strong variation of alignment with vibration. A multi-surface direct-interaction model is developed to interpret product alignment and population data. The predictions of this model for the reaction of calcium with fluorine show reasonable agreement with experiment

  3. 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.

  4. Calorimetry of 25 Ah lithium/thionyl chloride cells

    Science.gov (United States)

    Johnson, C. J.; Dawson, S.

    1991-01-01

    Heat flow measurements of 25-Ah lithium thionyl chloride cells provided a method to calculate an effective thermal potential, E(TP) of 3.907 V. The calculation is useful to determine specific heat generation of this cell chemistry and design. The E(TP) value includes heat generation by electrochemical cell reactions, competitive chemical reactions, and resistance heating at the tabs, connectors, and leads. Heat flow was measured while applying electrical loads to the cell in an isothermal calorimeter set at 0, 20, and 60 C.

  5. 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.

  6. Emf, maximum power and efficiency of fuel cells

    International Nuclear Information System (INIS)

    Gaggioli, R.A.; Dunbar, W.R.

    1990-01-01

    This paper discusses the ideal voltage of steady-flow fuel cells usually expressed by Emf = -ΔG/nF where ΔG is the Gibbs free energy of reaction for the oxidation of the fuel at the supposed temperature of operation of the cell. Furthermore, the ideal power of the cell is expressed as the product of the fuel flow rate with this emf, and the efficiency of a real fuel cell, sometimes called the Gibbs efficiency, is defined as the ratio of the actual power output to this ideal power. Such viewpoints are flawed in several respects. While it is true that if a cell operates isothermally the maximum conceivable work output is equal to the difference between the Gibbs free energy of the incoming reactants and that of the leaving products, nevertheless, even if the cell operates isothermally, the use of the conventional ΔG of reaction assumes that the products of reaction leave separately from one another (and from any unused fuel), and when ΔS of reaction is positive it assumes that a free heat source exists at the operating temperature, whereas if ΔS is negative it neglects the potential power which theoretically could be obtained form the heat released during oxidation. Moreover, the usual cell does not operate isothermally but (virtually) adiabatically

  7. Comparison of cell homogenization methods considering interaction effect between fuel cells and control rod cells

    International Nuclear Information System (INIS)

    Takeda, T.; Uto, N.

    1988-01-01

    Several methods to determine cell-averaged group cross sections and anisotropic diffusion coefficients which consider the interaction effect between core fuel cells and control rods or control rod followers have been compared to discuss the physical meaning included in cell homogenization. As the cell homogenization methods considered are the commonly used flux-weighting method, the reaction rate preservation method and the reactivity preservation method. These homogenization methods have been applied to control rod worth calculations in 1-D slab cores to investigate their applicability. (author). 6 refs, 2 figs, 9 tabs

  8. Hydrogen isotope exchange reaction rates in tritium, hydrogen and deuterium mixed gases

    International Nuclear Information System (INIS)

    Uda, Tatsuhiko

    1992-01-01

    Hydrogen isotope exchange reaction rates in H 2 +T 2 , D 2 +T 2 and H 2 +D 2 +T 2 mixed gases, as induced by tritium decay and beta radiation, were experimentally measured by laser Raman spectrometry. Initially a glass cell was filled with T 2 gas to a pressure of 30-40 kPa, and an equivalent partial pressure of H 2 and/or D 2 was added. The first-order hydrogen isotope exchange reaction rates were 5.54x10 -2 h -1 for H 2 +T 2 mixed gas and 4.76x10 -2 h -1 for D 2 +T 2 . The actual HT producing rate was nearly equivalent to the rate of DT, but the reverse reaction rate of HT was faster than that of DT. The exchange reaction rates between H, D and T showed the isotope effect, HD>HT>DT. The hydrogen isotope exchange reaction rates observed were about twenty times larger than ion formation rates by beta radiation. This result suggests that a free radical chain reaction in hydrogen isotopes is occurring. (orig.)

  9. 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.

  10. Hepcidin: an important iron metabolism regulator in chronic kidney disease.

    Science.gov (United States)

    Antunes, Sandra Azevedo; Canziani, Maria Eugênia Fernandes

    2016-01-01

    Anemia is a common complication and its impact on morbimortality in patients with chronic kidney disease (CKD) is well known. The discovery of hepcidin and its functions has contributed to a better understanding of iron metabolism disorders in CKD anemia. Hepcidin is a peptide mainly produced by hepatocytes and, through a connection with ferroportin, it regulates iron absorption in the duodenum and its release of stock cells. High hepcidin concentrations described in patients with CKD, especially in more advanced stages are attributed to decreased renal excretion and increased production. The elevation of hepcidin has been associated with infection, inflammation, atherosclerosis, insulin resistance and oxidative stress. Some strategies were tested to reduce the effects of hepcidin in patients with CKD, however more studies are necessary to assess the impact of its modulation in the management of anemia in this population. Resumo Anemia é uma complicação frequente e seu impacto na morbimortalidade é bem conhecido em pacientes com doença renal crônica (DRC). A descoberta da hepcidina e de suas funções contribuíram para melhor compreensão dos distúrbios do metabolismo de ferro na anemia da DRC. Hepcidina é um peptídeo produzido principalmente pelos hepatócitos, e através de sua ligação com a ferroportina, regula a absorção de ferro no duodeno e sua liberação das células de estoque. Altas concentrações de hepcidina descritas em pacientes com DRC, principalmente em estádios mais avançados, são atribuídas à diminuição da excreção renal e ao aumento de sua produção. Elevação de hepcidina tem sido associada à ocorrência de infecção, inflamação, aterosclerose, resistência à insulina e estresse oxidativo. Algumas estratégias foram testadas para diminuir os efeitos da hepcidina em pacientes com DRC, entretanto, serão necessários mais estudos para avaliar o impacto de sua modulação no manejo da anemia nessa população.

  11. Using cerium anomaly as an indicator of redox reactions in constructed wetland

    Science.gov (United States)

    Liang, R.

    2013-12-01

    The study area, Chiayi County located in southern Taiwan, has highly developed livestock. The surface water has very low dissolved oxygen and high NH4. Under the situation, constructed wetland becomes the most effective and economic choice to treat the wastewater in the natural waterways. Hebao Island free surface constructed wetland started to operate in late 2006. It covers an area of 0.28 km2 and is subdivided into 3 major cells, which are sedimentation cell, 1st aeration cell with rooted plants and 2nd aeration cell with float plants. The water depth of cells ranges from 0.6 m to 1.2 m. The total hydraulic retention time is about a half day. In this study, the water samples were sequentially collected along the flow path. The results of hydrochemical analysis show that the untreated inflow water can be characterized with enriched NH4 (11 ppm), sulfate (6 ppm) and arsenic (50 ppb). The removal efficiency of NH4 in the first two cells is arsenic is still higher than the permissible limits recommended by WHO (10 ppb). The wetland operation should be tuned to take more arsenic away in the future. As demonstrated in the above, oxidation reaction is the most dominant mechanism to remove pollutants from the wastewater; therefore, dissolved oxygen is traditionally considered as an important indicator to evaluate the operation efficiency of wetland. However, it would need longer time to achieve equilibrium state of redox reaction involving dissolved oxygen due to the slower reaction rate. For example, the input water in this study has fairly high dissolved oxygen (5 ppm) but the NH4 content is still high, which indicates a non-equilibrium condition. In this study, the cerium anomaly is alternatively utilized to evaluate the water redox state. The results demonstrate that the input water has the negative cerium anomaly of -0.16. Along the flow path, the cerium negative anomaly does not change in the first two cells and dramatically becomes -0.23 in cell 3. The trend of

  12. (n,α reactions cross section research at IPPE

    Directory of Open Access Journals (Sweden)

    Giorginis G.

    2012-02-01

    Full Text Available An experimental set-up based on an ionization chamber with a Frisch grid and wave form digitizer was used for (n,α cross section measurements. Use of digital signal processing allowed us to select a gaseous cell inside the sensitive area of the ionization chamber and determine the target atoms in it with high accuracy. This kind of approach provided us with a powerful method to suppress background arising from the detector structure and parasitic reactions on the working gas components. This method is especially interesting to study neutron reactions with elements for which solid target preparation is difficult (noble gases for example. In the present experiments we used a set of working gases which contained admixtures of nitrogen, oxygen, neon, argon and boron. Fission of 238U was used as neutron flux monitor. The cross section of the (n,α reaction for 16O, 14N, 20Ne, 36Ar, 40Ar and the yield ratio α0/α1 of 10B(n,α0 to 10B(n,α1 reactions was measured for neutron energies between 1.5 and 7 MeV. Additionally a measurement of the 50Cr(n,α cross section using a solid chromium target is also reported.

  13. Donor Vδ1+ γδ T cells expand after allogeneic hematopoietic stem cell transplantation and show reactivity against CMV-infected cells but not against progressing B-CLL.

    Science.gov (United States)

    Prinz, Immo; Thamm, Kristina; Port, Matthias; Weissinger, Eva M; Stadler, Michael; Gabaev, Ildar; Jacobs, Roland; Ganser, Arnold; Koenecke, Christian

    2013-05-11

    γδ T lymphocytes play an important role in immune reactions towards infections and malignancies. In particular, Vγ9-Vδ1+ T lymphocytes are thought to play protective antiviral roles in human CMV infection. Recently, Vδ1+ T lymphocytes were proposed to also have anti- B-CLL reactivity. Here we report a case of 48-year-old man who received allogeneic stem cell transplantation for progressive B-CLL. Within one year after transplantation, lymphoma relapsed despite a dramatic increase of Vδ1+ T cells in the patient's blood. In vitro killing assays revealed activity of patient's γδ cells against CMV target cells, but not against the relapsing lymphoma-cells. This argues for a contribution of Vδ1+ cells in the immune reaction against CMV reactivation, but does not support a strong correlation of expanded Vδ1+ T cells and favorable disease outcome in B-CLL patients.

  14. 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

  15. The Influence of the Transportation Environment on Driving Reduction and Cessation.

    Science.gov (United States)

    Vivoda, Jonathon M; Heeringa, Steven G; Schulz, Amy J; Grengs, Joe; Connell, Cathleen M

    2017-10-01

    Driving is by far the most common mode of transportation in the United States, but driving ability is known to decline as people experience age-related functional declines. Some older adults respond to such declines by self-limiting their driving to situations with a low perceived risk of crashing, and many people eventually stop driving completely. Previous research has largely focused on individual and interpersonal predictors of driving reduction and cessation (DRC). The purpose of this study was to assess the influence of the transportation environment on DRC. Data were combined from the Health and Retirement Study, the Urban Mobility Scorecard, and StreetMap North America (GIS data). Longitudinal survival analysis techniques were used to analyze seven waves of data spanning a 12-year period. As roadway density and congestion increased in the environment, the odds of DRC also increased, even after controlling for individual and interpersonal predictors. Other predictors of DRC included demographics, relationship status, health, and household size. The current study identified an association between the transportation environment and DRC. Future research is needed to determine whether a causal link can be established. If so, modifications to the physical environment (e.g., creating livable communities with goods and services in close proximity) could reduce driving distances in order to improve older drivers' ability to remain engaged in life. In addition, older individuals who wish to age in place should consider how their local transportation environment may affect their quality of life. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Critical Factors for Successful Practice of Disaster-Resilient Community in Urban City

    Science.gov (United States)

    Chou, J. S.; Wu, J. H.

    2017-12-01

    Due to special geographical environment, Taiwan is a natural disaster-prone area, which often suffers from earthquakes, typhoons and other natural hazards, resulting in heavy casualties and huge property losses. Furthermore, effect of global warming increases extreme climate events and leads to frequent and severe natural disasters. Therefore, disaster prevention and response are not only an important issue of government policy, but also a critical issue of people's life. Rather than over-reliance on government assistance, the spontaneous participation and co-operation by people can complete specific disaster preparedness and reinforce local energy of disaster prevention and response. Although the concept of disaster-resilient community (DRC) has been shaped for a period of time, residents in the community cannot keep up the pace with government, which may decrease the effectiveness of DRC development. Thus, the study of theory and practice of urban DRC becomes an imperative need. This article is a qualitative case study, which uses the participant observation and self-reflection in action research methods to collect relevant information for empirical validation. Particularly, this investigation is supplemented by service work experience in DRC promotion conducted by the researchers. According to the qualitative analyses of case communities during training process of disaster prevention and preparedness, we can identify the critical factors affecting the level of community-based disaster prevention and protection works. Based on the literature and empirical supports, the factors are discussed through three spindle constructs respectively, namely coping strategy, operations management and organizational behavior. Based on the findings of this study, we make conclusions and suggestions for related authority in sustainably promoting DRC.

  17. Procedures for Decomposing a Redox Reaction into Half-Reaction

    Science.gov (United States)

    Fishtik, Ilie; Berka, Ladislav H.

    2005-01-01

    A simple algorithm for a complete enumeration of the possible ways a redox reaction (RR) might be uniquely decomposed into half-reactions (HRs) using the response reactions (RERs) formalism is presented. A complete enumeration of the possible ways a RR may be decomposed into HRs is equivalent to a complete enumeration of stoichiometrically…

  18. 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...

  19. Experimental study of the (n,alpha) reaction on a set of light nuclei

    International Nuclear Information System (INIS)

    Khryachkov, V.A.; Bondarenko, I.P.; Kuzminov, B.D.; Semenova, N.N.; Sergachev, A.I.; Giorginis, G.

    2011-01-01

    An experimental setup based on an ionization chamber with Frisch grid and waveform digitizer was used for (n,α) cross-section measurements. The use of digital signal processing has allowed us to select a gaseous cell inside the sensitive area of the ionisation chamber with high accuracy. This kind of approach provides a powerful method to suppress background from detector components and parasitic reactions on the working gas. The new method is especially interesting for the study of reactions on elements for which solid target preparation is difficult (e.g. noble gases). Additionally it has the advantage of an accurate determination of the number of nonradioactive nuclei in the selected gas cell. In the present experiments a set of working gases was used, which contained admixtures of nitrogen, oxygen, neon, argon and boron. Fission of "2"3"8U was used as neutron flux monitor. The cross-section of the (n,α) reaction for "1"6O, "1"4N, "2"0Ne, "3"6Ar, "4"0Ar and the branching ratio α_0/α_1 of the "1"0B(n,α_0) to "1"0B(n,α_1) reactions were measured for neutron energies between 1.5 and 7 MeV. (authors)

  20. Cognate antigen stimulation generates potent CD8+ inflammatory effector T cells.

    Directory of Open Access Journals (Sweden)

    Hsueh-Cheng eSung

    2013-12-01

    Full Text Available Inflammatory reactions are believed to be triggered by innate signals and have a major protective role by recruiting innate immunity cells, favoring lymphocyte activation and differentiation, and thus contributing to the sequestration and elimination of the injurious stimuli. Although certain lymphocyte types such as TH17 cells co-participate in inflammatory reactions, their generation from the naïve pool requires the pre-existence of an inflammatory milieu. In this context, inflammation is always regarded as beginning with an innate response that may be eventually perpetuated and amplified by certain lymphocyte types. In contrast, we here show that even in sterile immunizations or in MyD88 deficient mice, CD8 T cells produce a burst of pro-inflammatory cytokines and chemokines. These functions follow opposite rules to the classic CD8 effector functions since they are generated prior to cell expansion and decline before antigen elimination. As few as 56 CD8+ inflammatory effector cells in a lymph node can mobilize 107 cells in 24h, including lymphocytes, natural killer cells and several accessory cell types involved in inflammatory reactions. Thus, although inflammation modulates cognate responses, CD8 cognate responses also initiate local inflammatory reactions.

  1. 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.

  2. 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.

  3. Ultralocalized thermal reactions in subnanoliter droplets-in-air.

    Science.gov (United States)

    Salm, Eric; Guevara, Carlos Duarte; Dak, Piyush; Dorvel, Brian Ross; Reddy, Bobby; Alam, Muhammad Ashraf; Bashir, Rashid

    2013-02-26

    Miniaturized laboratory-on-chip systems promise rapid, sensitive, and multiplexed detection of biological samples for medical diagnostics, drug discovery, and high-throughput screening. Within miniaturized laboratory-on-chips, static and dynamic droplets of fluids in different immiscible media have been used as individual vessels to perform biochemical reactions and confine the products. Approaches to perform localized heating of these individual subnanoliter droplets can allow for new applications that require parallel, time-, and space-multiplex reactions on a single integrated circuit. Our method positions droplets on an array of individual silicon microwave heaters on chip to precisely control the temperature of droplets-in-air, allowing us to perform biochemical reactions, including DNA melting and detection of single base mismatches. We also demonstrate that ssDNA probe molecules can be placed on heaters in solution, dried, and then rehydrated by ssDNA target molecules in droplets for hybridization and detection. This platform enables many applications in droplets including hybridization of low copy number DNA molecules, lysing of single cells, interrogation of ligand-receptor interactions, and rapid temperature cycling for amplification of DNA molecules.

  4. 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.

  5. The shielded chemistry suite at BNL and its use in the study of the irradiated uranium-water reaction

    International Nuclear Information System (INIS)

    Bannister, G.H.; Tyfield, S.P.

    1977-11-01

    A versatile shielded facility for chemical studies is now in use at Berkeley Nuclear Laboratories. The suite was fully commissioned in 1976 and first utilised to study the aqueous corrosion of irradiated reactor grade uranium. The suite consists of three adjacent interconnected cells; a balance cell, a preparation cell and an experimental cell. The development, design and layout of the facilities are described, as are the details of the equipment installed to undertake a uranium corrosion study. The preparation cell is used for procedures that could results in high levels of contamination, such as cutting of uranium specimens. The uranium samples are corroded in sealed steel capsules installed in the experimental cell. The capsules are heated either isothermally or through a transient and the reaction monitored with a pressure transducer which records the rate of hydrogen evolution from the uranium-water reaction. The experimental results will be reported elsewhere. (author)

  6. Reaction energetics on long-range corrected density functional theory: Diels-Alder reactions.

    Science.gov (United States)

    Singh, Raman K; Tsuneda, Takao

    2013-02-15

    The possibility of quantitative reaction analysis on the orbital energies of long-range corrected density functional theory (LC-DFT) is presented. First, we calculated the Diels-Alder reaction enthalpies that have been poorly given by conventional functionals including B3LYP functional. As a result, it is found that the long-range correction drastically improves the reaction enthalpies. The barrier height energies were also computed for these reactions. Consequently, we found that dispersion correlation correction is also crucial to give accurate barrier height energies. It is, therefore, concluded that both long-range exchange interactions and dispersion correlations are essentially required in conventional functionals to investigate Diels-Alder reactions quantitatively. After confirming that LC-DFT accurately reproduces the orbital energies of the reactant and product molecules of the Diels-Alder reactions, the global hardness responses, the halves of highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy gaps, along the intrinsic reaction coordinates of two Diels-Alder reactions were computed. We noticed that LC-DFT results satisfy the maximum hardness rule for overall reaction paths while conventional functionals violate this rule on the reaction pathways. Furthermore, our results also show that the HOMO-LUMO gap variations are close to the reaction enthalpies for these Diels-Alder reactions. Based on these results, we foresee quantitative reaction analysis on the orbital energies. Copyright © 2012 Wiley Periodicals, Inc.

  7. Optimization of the THP-1 activation assay to detect pharmaceuticals with potential to cause immune mediated drug reactions.

    Science.gov (United States)

    Corti, Daniele; Galbiati, Valentina; Gatti, Nicolò; Marinovich, Marina; Galli, Corrado L; Corsini, Emanuela

    2015-10-01

    Despite important impacts of systemic hypersensitivity induced by pharmaceuticals, for such endpoint no reliable preclinical approaches are available. We previously established an in vitro test to identify contact and respiratory allergens based on interleukin-8 (IL-8) production in THP-1 cells. Here, we challenged it for identification of pharmaceuticals associated with systemic hypersensitivity reactions, with the idea that drug sensitizers share common mechanisms of cell activation. Cells were exposed to drugs associated with systemic hypersensitivity reactions (streptozotocin, sulfamethoxazole, neomycin, probenecid, clonidine, procainamide, ofloxacin, methyl salicylate), while metformin was used as negative drug. Differently to chemicals, drugs tested were well tolerated, except clonidine and probenecid, with no signs of cytotoxicity up to 1-2mg/ml. THP-1 activation assay was adjusted, and conditions, that allow identification of all sensitizing drugs tested, were established. Next, using streptozotocin and selective inhibitors of PKC-β and p38 MAPK, two pathways involved in chemical allergen-induced cell activation, we tested the hypothesis that similar pathways were also involved in drug-induced IL-8 production and CD86 upregulation. Results indicated that drugs and chemical allergens share similar activation pathways. Finally, we made a structure-activity hypothesis related to hypersensitivity reactions, trying to individuate structural requisite that can be involved in immune mediated adverse reactions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Peacekeeping in the Congo, 1999-2001: Success or Failure?

    Science.gov (United States)

    2014-05-22

    War. President Nelson Mandela was the chairman of the South African Development Community (SADC) in the summer of 1998 when the war broke out in the...DRC. President Mandela attempted to use his influence to bring peace to the region. On 3 September 1998, after high-level SADC meetings, President... Mandela announced the community’s support for the military interventions by its member states in the DRC conflict. President Mandela and his

  9. The Effect of China’s Scramble for Resources and African Resource Nationalism on the Supply of Strategic Southern African Minerals: What Can the United States Do?

    Science.gov (United States)

    2010-01-01

    infrastructure remains the major impediment to sustaining and developing mining in South Africa, and it is a problem in the Democratic Republic of the Congo ...majority rule in 1994. The South African National Planning Commission, headed by former Finance Minister Trevor Manuel , pointed out in its “Vision for...Nationalism in the DRC In the Democratic Republic of the Congo (DRC), President Joseph Kabila leads a neo-patrimonial regime in a recovering failed

  10. Determination of 210Pb at ultra-trace levels in water by ICP-MS

    International Nuclear Information System (INIS)

    Lariviere, D.; Reiber, K.M.; Evans, R.D.; Cornett, R.J.

    2005-01-01

    210 Pb (t 1/2 = 22.26 years) is one of the most difficult naturally occurring radionuclides to analyze directly via radiometric measurement due to its low-energy radioactive decay. In this work, inductively coupled plasma mass spectrometry (ICP-MS) was investigated as a possible alternative to radiometric counting for the determination of 210 Pb. The formation of isobaric and polyatomic (molecular) interferences was studied and various strategies (i.e. co-precipitation, extraction chromatography, and derivatization) were tested to assess their usefulness in reducing these interferences. In addition, the potential of these strategies as pre-concentration methods was demonstrated. A 210 Pb pre-concentration of >300-fold and recoveries of 63-73% were obtained using a combined co-precipitation and extraction chromatography protocol followed by derivatization using an ethylating reagent. The abundance sensitivity at m/z = 210 in the presence of stable Pb was also investigated for three types of mass spectrometers (sector-field (ICP-SFMS), quadrupole-based (ICP-QMS), and quadrupole-based with a dynamic reaction cell (ICP-QMS (DRC))). Finally, the method was applied to determine 210 Pb in water samples and a detection limit of 90 mBq L -1 (10 pg L -1 ) was obtained

  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. Non-ionic iodinated contrast media related immediate reactions: A mechanism study of 27 patients.

    Science.gov (United States)

    Zhai, Liqin; Guo, Xiangjie; Zhang, Haoyue; Jin, Qianqian; Zeng, Qiang; Tang, Xiaoxian; Gao, Cairong

    2017-01-01

    The underlying mechanism of non-ionic iodinated contrast media-related immediate reactions was evaluated in this study. Patients presenting at least grade II immediate reactions after non-ionic iodinated contrast media injection were enrolled. Basophil activation was evaluated by flow cytometry. The plasma concentration of human terminal complement complex SC5b-9, as well as concentrations of serum chymase, tryptase, human mast cell carboxypeptidase A3, human prostaglandin D2, and total IgE were measured by enzyme-linked immunosorbent assay. The basophil activation percentage was significantly higher in the study group than in the control group (17.94±21.06% vs 3.45±1.49%). The plasma concentration of human terminal complement complex SC5b-9 and concentrations of serum chymase, human mast cell carboxypeptidase A3, prostaglandin D2, tryptase, and total IgE were also significantly increased (236.99±318.21 vs 49.70±30.41ng/mL, 0.41±0.49 vs 0.09±0.06ng/mL, 1.17±0.67 vs 0.30±0.17ng/mL, 203.52±137.27 vs 102.28±48.72pg/mL, 3.81±0.22 vs 2.70±0.16ng/mL, 102.00±51.84 vs 19.97±2.75ng/mL, respectively). Both mast cells and basophils were activated in non-ionic iodinated contrast media to mediate immediate hypersensitivity, and mast cells may be involved. Different mechanisms, including IgE-dependent, complement-dependent, and direct membrane effects, contributed to mast cell and basophil activation. Individual patients may use a single or combined mechanism involving single or combined mast cells and basophils. Immediate reactions following non-ionic iodinated contrast media injection may be a mechanically heterogenous disease. Copyright © 2016. Published by Elsevier B.V.

  14. Inflammatory and redox reactions in colorectal carcinogenesis.

    Science.gov (United States)

    Guina, Tina; Biasi, Fiorella; Calfapietra, Simone; Nano, Mario; Poli, Giuseppe

    2015-03-01

    It has been established that there is a relationship between chronic inflammation and cancer development. The constant colonic inflammation typical of inflammatory bowel diseases is now considered a risk factor for colorectal carcinoma (CRC) development. The inflammatory network of signaling molecules is also required during the late phases of carcinogenesis, to enable cancer cells to survive and to metastasize. Oxidative reactions are an integral part of the inflammatory response, and are generally associated with CRC development. However, when the malignant phenotype is acquired, increased oxidative status induces antioxidant defenses in cancer cells, favoring their aggressiveness. This contradictory behavior of cancer cells toward redox status is of great significance for potential anticancer therapies. This paper summarizes the essential background information relating to the molecules involved in regulating oxidative stress and inflammation during carcinogenesis. Understanding more of their function in CRC stages might provide the foundation for future developments in CRC treatment. © 2015 New York Academy of Sciences.

  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. Immune reaction and colorectal cancer: friends or foes?

    Science.gov (United States)

    Formica, Vincenzo; Cereda, Vittore; Nardecchia, Antonella; Tesauro, Manfredi; Roselli, Mario

    2014-09-21

    The potential clinical impact of enhancing antitumor immunity is increasingly recognized in oncology therapeutics for solid tumors. Colorectal cancer is one of the most studied neoplasms for the tumor-host immunity relationship. Although immune cell populations involved in such a relationship and their prognostic role in colorectal cancer development have clearly been identified, still no approved therapies based on host immunity intensification have so far been introduced in clinical practice. Moreover, a recognized risk in enhancing immune reaction for colitis-associated colorectal cancer development has limited the emphasis of this approach. The aim of the present review is to discuss immune components involved in the host immune reaction against colorectal cancer and analyze the fine balance between pro-tumoral and anti-tumoral effect of immunity in this model of disease.

  17. Alloactivated HLA class II-positive T-cell lines induce IL-2 reactivity but lack accessory cell function in mixed leukocyte culture

    DEFF Research Database (Denmark)

    Odum, N; Dickmeiss, E; Hofmann, B

    1989-01-01

    in the primary mixed leukocyte reaction (median counts per minute (cpm) 5.5 x 10(3] was significantly lower than that of peripheral blood mononuclear cells (cpm: 44.0 x 10(3]. The stimulation by Ta was almost only seen when the Ta were specifically directed against the class II antigens of the responder...... peripheral blood mononuclear cells (i.e., in combinations with "backstimulation") (median cpm: 21,000). In mixed leukocyte reaction combinations without backstimulation, significantly weaker reactions were seen (median cpm: 1,000). This observation may explain previous controversies concerning...

  18. Diffusion-controlled reactions modeling in Geant4-DNA

    Energy Technology Data Exchange (ETDEWEB)

    Karamitros, M., E-mail: matkara@gmail.com [CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, INCIA, UMR 5287, F-33400 Talence (France); Luan, S. [University of New Mexico, Department of Computer Science, Albuquerque, NM (United States); Bernal, M.A. [Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, SP (Brazil); Allison, J. [Geant4 Associates International Ltd (United Kingdom); Baldacchino, G. [CEA Saclay, IRAMIS, LIDYL, Radiation Physical Chemistry Group, F-91191 Gif sur Yvette Cedex (France); CNRS, UMR3299, SIS2M, F-91191 Gif sur Yvette Cedex (France); Davidkova, M. [Nuclear Physics Institute of the ASCR, Prague (Czech Republic); Francis, Z. [Saint Joseph University, Faculty of Sciences, Department of Physics, Mkalles, Beirut (Lebanon); Friedland, W. [Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Radiation Protection, Ingolstädter Landstr. 1, 85764 Neuherberg (Germany); Ivantchenko, V. [Ecoanalytica, 119899 Moscow (Russian Federation); Geant4 Associates International Ltd (United Kingdom); Ivantchenko, A. [Geant4 Associates International Ltd (United Kingdom); Mantero, A. [SwHaRD s.r.l., via Buccari 9, 16153 Genova (Italy); Nieminem, P.; Santin, G. [ESA-ESTEC, 2200 AG Noordwijk (Netherlands); Tran, H.N. [Division of Nuclear Physics and Faculty of Applied Sciences, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Stepan, V. [CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Nuclear Physics Institute of the ASCR, Prague (Czech Republic); Incerti, S., E-mail: incerti@cenbg.in2p3.fr [CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France)

    2014-10-01

    Context Under irradiation, a biological system undergoes a cascade of chemical reactions that can lead to an alteration of its normal operation. There are different types of radiation and many competing reactions. As a result the kinetics of chemical species is extremely complex. The simulation becomes then a powerful tool which, by describing the basic principles of chemical reactions, can reveal the dynamics of the macroscopic system. To understand the dynamics of biological systems under radiation, since the 80s there have been on-going efforts carried out by several research groups to establish a mechanistic model that consists in describing all the physical, chemical and biological phenomena following the irradiation of single cells. This approach is generally divided into a succession of stages that follow each other in time: (1) the physical stage, where the ionizing particles interact directly with the biological material; (2) the physico-chemical stage, where the targeted molecules release their energy by dissociating, creating new chemical species; (3) the chemical stage, where the new chemical species interact with each other or with the biomolecules; (4) the biological stage, where the repairing mechanisms of the cell come into play. This article focuses on the modeling of the chemical stage. Method This article presents a general method of speeding-up chemical reaction simulations in fluids based on the Smoluchowski equation and Monte-Carlo methods, where all molecules are explicitly simulated and the solvent is treated as a continuum. The model describes diffusion-controlled reactions. This method has been implemented in Geant4-DNA. The keys to the new algorithm include: (1) the combination of a method to compute time steps dynamically with a Brownian bridge process to account for chemical reactions, which avoids costly fixed time step simulations; (2) a k–d tree data structure for quickly locating, for a given molecule, its closest reactants. The

  19. The effect of vitamin E on acute skin reaction caused by radiotherapy.

    Science.gov (United States)

    Dirier, A; Akmansu, M; Bora, H; Gurer, M

    2007-09-01

    Ionizing radiation affects healthy organs and tissues as well as diseased tissues during radiation therapy. Skin reactions varying from acute erythema to necrosis can be seen. It has been found that vitamin E can prevent mutagenic and/or carcinogenic effects of ionizing radiation in both animals and cell cultures. This study investigated the preventative effect of antioxidant vitamin E on irradiation-induced acute skin reactions. No protective effect of vitamin E was demonstrated. It is possible that the vehicle induced free radical exposure in the irradiated skin.

  20. Experimental and numerical reaction analysis on sodium-water chemical reaction field

    International Nuclear Information System (INIS)

    Deguchi, Yoshihiro; Takata, Takashi; Yamaguchi, Akira; Kikuchi, Shin; Ohshima, Hiroyuki

    2015-01-01

    In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. On the other hand, it has strong chemical reactivity with water vapor. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes. This process ends up damages on the heat transport equipment in the SFR. Therefore, the study on sodium-water chemical reactions is of paramount importance for security reasons. This study aims to clarify the sodium-water reaction mechanisms using an elementary reaction analysis. A quasi one-dimensional flame model is applied to a sodium-water counter-flow reaction field. The analysis contains 25 elementary reactions, which consist of 17 H_2-O_2 and 8 Na-H_2O reactions. Temperature and species concentrations in the counter-flow reaction field were measured using laser diagnostics such as LIF and CARS. The main reaction in the experimental conditions is Na+H_2O → NaOH+H and OH is produced by H_2O+H → H_2+OH. It is demonstrated that the reaction model in this study well explains the structure of the sodium-water counter-flow diffusion flame. (author)