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Mezyk SP, Baxter M, Celis-Barros C, Grimes TS, Zalupski PR, Rae C, Zarzana CA, Cook AR, Horne GP. Effect of f-element complexation on the radiolysis of 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]). Dalton Trans 2024; 53:6881-6891. [PMID: 38407412 DOI: 10.1039/d4dt00424h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
A systematic study of the impact on the chemical reactivity of the oxidising n-dodecane radical cation (RH˙+) with f-element complexed 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) has been undertaken utilizing time-resolved electron pulse radiolysis/transient absorption spectroscopy and high-level quantum mechanical calculations. Lanthanide ion complexed species, [Ln((HEH[EHP])2)3], exhibited vastly increased reactivity (over 10× faster) in comparison to the non-complexed ligand in n-dodecane solvent, whose rate coefficient was k = (4.66 ± 0.22) × 109 M-1 s-1. Similar reactivity enhancement was also observed for the corresponding americium ion complex, k = (5.58 ± 0.30) × 1010 M-1 s-1. The vastly increased reactivity of these f-element complexes was not due to simple increased diffusion-control of these reactions; rather, enhanced hole transfer mechanisms for the complexes were calculated to become energetically more favourable. Interestingly, the observed reactivity trend with lanthanide ion size was not linear; instead, the rate coefficients showed an initial increase (Lu to Yb) followed by a decrease (Tm to Ho), followed by another increase (Dy to La). This behaviour was excellently predicted by the calculated reaction volumes of these complexes. Complementary cobalt-60 gamma irradiations for select lanthanide complexes demonstrated that the measured kinetic differences translated to increased ligand degradation at steady-state timescales, affording ∼38% increase in ligand loss of a 1 : 1 [La((HEH[EHP])2)3] : HEH[EHP] ratio system.
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Affiliation(s)
- Stephen P Mezyk
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, CA 90804, USA.
| | - Makayla Baxter
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
- Center for Radiation Chemistry Research, Idaho National Laboratory, Idaho Falls, ID, P.O. Box 1625, 83415, USA.
| | | | - Travis S Grimes
- Center for Radiation Chemistry Research, Idaho National Laboratory, Idaho Falls, ID, P.O. Box 1625, 83415, USA.
| | - Peter R Zalupski
- Center for Radiation Chemistry Research, Idaho National Laboratory, Idaho Falls, ID, P.O. Box 1625, 83415, USA.
| | - Cathy Rae
- Center for Radiation Chemistry Research, Idaho National Laboratory, Idaho Falls, ID, P.O. Box 1625, 83415, USA.
| | - Christopher A Zarzana
- Center for Radiation Chemistry Research, Idaho National Laboratory, Idaho Falls, ID, P.O. Box 1625, 83415, USA.
| | - Andrew R Cook
- Department of Chemistry, Brookhaven National Laboratory, Upton, New York, 11973, USA
| | - Gregory P Horne
- Center for Radiation Chemistry Research, Idaho National Laboratory, Idaho Falls, ID, P.O. Box 1625, 83415, USA.
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Rotermund BM, Mezyk SP, Sperling JM, Beck NB, Wineinger H, Cook AR, Albrecht-Schönzart TE, Horne GP. Correction to "Chemical Kinetics for the Oxidation of Californium(III) Ions with Select Radiation-Induced Inorganic Radicals (Cl 2•- and SO 4•-)". J Phys Chem A 2024; 128:1736. [PMID: 38382054 DOI: 10.1021/acs.jpca.4c00876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
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3
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Rotermund BM, Mezyk SP, Sperling JM, Beck NB, Wineinger H, Cook AR, Albrecht-Schönzart TE, Horne GP. Chemical Kinetics for the Oxidation of Californium(III) Ions with Select Radiation-Induced Inorganic Radicals (Cl 2•- and SO 4•-). J Phys Chem A 2024; 128:590-598. [PMID: 38215218 DOI: 10.1021/acs.jpca.3c07404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2024]
Abstract
Despite the availability of transuranic elements increasing in recent years, our understanding of their most basic and inherent radiation chemistry is limited and yet essential for the accurate interpretation of their physical and chemical properties. Here, we explore the transient interactions between trivalent californium ions (Cf 3 + ) and select inorganic radicals arising from the radiolytic decomposition of common anions and functional group constituents, specifically the dichlorine (Cl2•-) and sulfate (SO4•-) radical anions. Chemical kinetics, as measured using integrated electron pulse radiolysis and transient absorption spectroscopy techniques, are presented for the reactions of these two oxidizing radicals with Cf 3 + ions. The derived and ionic strength-corrected second-order rate coefficients (k) for these radiation-induced processes are k(Cf 3 + + Cl2•-) = (8.28 ± 0.61) × 105 M-1 s-1 and k(Cf 3 + + SO4•-) = (9.50 ± 0.43) × 108 M-1 s-1 under ambient temperature conditions (22 ± 1 °C).
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Affiliation(s)
- Brian M Rotermund
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Stephen P Mezyk
- Department of Chemistry and Biochemistry, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840-9507, United States
| | - Joseph M Sperling
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Nicholas B Beck
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Hannah Wineinger
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Andrew R Cook
- Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Thomas E Albrecht-Schönzart
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Gregory P Horne
- Center for Radiation Chemistry Research, Idaho National Laboratory, Idaho Falls, P.O. Box 1625, Idaho 83415, United States
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Koh JS, Cook AR, Seet RCS. Low incidence of neurological recurrent side effects following COVID-19 reimmunization. QJM 2023; 116:1039. [PMID: 37364012 DOI: 10.1093/qjmed/hcad153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Indexed: 06/28/2023] Open
Affiliation(s)
- J S Koh
- Department of Neurology, National Neuroscience Institute (Tan Tock Seng Hospital Campus), Singapore
| | - A R Cook
- Saw Swee Hock School of Public Health, National University Singapore and National University Health System, Singapore
| | - R C S Seet
- Division of Neurology, Department of Medicine, National University Health System, Singapore
- Department of Medicine, Yong Loo Lin School of Medicine, National University Singapore, Singapore
- Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University Singapore, Singapore
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Horne GP, Celis-Barros C, Conrad JK, Grimes TS, McLachlan JR, Rotermund BM, Cook AR, Mezyk SP. Impact of lanthanide ion complexation and temperature on the chemical reactivity of N, N, N', N'-tetraoctyl diglycolamide (TODGA) with the dodecane radical cation. Phys Chem Chem Phys 2023. [PMID: 37294439 DOI: 10.1039/d3cp01119d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The impact of trivalent lanthanide ion complexation and temperature on the chemical reactivity of N,N,N',N'-tetraoctyl diglycolamide (TODGA) with the n-dodecane radical cation (RH˙+) has been measured by electron pulse radiolysis and evaluated by quantum mechanical calculations. Additionally, Arrhenius parameters were determined for the reaction of the non-complexed TODGA ligand with the RH˙+ from 10-40 °C, giving the activation energy (Ea = 17.43 ± 1.64 kJ mol-1) and pre-exponential factor (A = (2.36 ± 0.05) × 1013 M-1 s-1). The complexation of Nd(III), Gd(III), and Yb(III) ions by TODGA yielded [LnIII(TODGA)3(NO3)3] complexes that exhibited significantly increased reactivity (up to 9.3× faster) with the RH˙+, relative to the non-complexed ligand: k([LnIII(TODGA)3(NO3)3] + RH˙+) = (8.99 ± 0.93) × 1010, (2.88 ± 0.40) × 1010, and (1.53 ± 0.34) × 1010 M-1 s-1, for Nd(III), Gd(III), and Yb(III) ions, respectively. The rate coefficient enhancement measured for these complexes exhibited a dependence on atomic number, decreasing as the lanthanide series was traversed. Preliminary reaction free energy calculations-based on a model [LnIII(TOGDA)]3+ complex system-indicate that both electron/hole and proton transfer reactions are energetically unfavorable for complexed TODGA. Furthermore, complementary average local ionization energy calculations showed that the most reactive region of model N,N,N',N'-tetraethyl diglycolamide (TEDGA) complexes, [LnIII(TEGDA)3(NO3)3], toward electrophilic attack is for the coordinated nitrate (NO3-) counter anions. Therefore, it is possible that radical reactions with the complexed NO3- counter anions dominate the differences in rates seen for the [LnIII(TODGA)3(NO3)3] complexes, and are likely responsible for the reported radioprotection in the presence of TODGA complexes.
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Affiliation(s)
- Gregory P Horne
- Center for Radiation Chemistry Research, Idaho National Laboratory, Idaho Falls, ID, P.O. Box 1625, 83415, USA.
| | - Cristian Celis-Barros
- Department of Chemistry, Colorado School of Mines, Golden, Colorado 80401, USA
- Nuclear Science and Engineering Program, Colorado School of Mines, Golden, Colorado 80401, USA
| | - Jacy K Conrad
- Center for Radiation Chemistry Research, Idaho National Laboratory, Idaho Falls, ID, P.O. Box 1625, 83415, USA.
| | - Travis S Grimes
- Center for Radiation Chemistry Research, Idaho National Laboratory, Idaho Falls, ID, P.O. Box 1625, 83415, USA.
| | - Jeffrey R McLachlan
- Center for Radiation Chemistry Research, Idaho National Laboratory, Idaho Falls, ID, P.O. Box 1625, 83415, USA.
- Department of Chemistry, Florida International University, Miami, Florida 33199, USA
| | - Brian M Rotermund
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - Andrew R Cook
- Department of Chemistry, Brookhaven National Laboratory, Upton, New York, 11973, USA
| | - Stephen P Mezyk
- Department of Chemistry and Biochemistry, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach California, 90840-9507, USA.
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Conrad JK, Iwamatsu K, Woods ME, Gakhar R, Layne B, Cook AR, Horne GP. Impact of iodide ions on the speciation of radiolytic transients in molten LiCl-KCl eutectic salt mixtures. Phys Chem Chem Phys 2023. [PMID: 37272071 DOI: 10.1039/d3cp01477k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The fate of fission-product iodine is critical for the deployment of next generation molten salt reactor technologies, owing to its volatility and biological impacts if it were to be released into the environment. To date, little is known on how ionizing radiation fields influence the redox chemistry, speciation, and transport of iodine in high temperature molten salts. Here we employ picosecond electron pulse irradiation techniques to elucidate for the first time the impact of iodide ions (I-) on the speciation and chemical kinetics of the primary radiation-induced transient radicals generated in molten chloride salt mixtures (eS- and Cl2˙-) as a function of temperature (400-700 °C). In the presence of I- ions (≥ 1 wt% KI in LiCl-KCl eutectic), we find that the transient spectrum following the electron pulse is composed of at least three overlapping species: the eS- and the Cl2˙- and ICl˙- radical anions, for which a deconvoluted spectrum of the latter is reported here for the first time in molten salts. This new transient spectrum was consistent with gas phase density functional theory calculations. The lifetime of the eS- was unaffected by the addition of I- ions. The newly observed interhalogen radical anion, ICl˙-, exhibited a lifetime on the order of microseconds over the investigated temperature range. The associated chemical kinetics indicate that the predominate mechanism of ICl˙- decay is via reaction with the Cl2˙- radical anion. The iodine containing product of this reaction is expected to be ICl2-, which will have implications for the transport of fission-product iodine in MSR technologies.
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Affiliation(s)
- Jacy K Conrad
- Center for Radiation Chemistry Research, Idaho National Laboratory, Idaho Falls, ID, P.O. Box 1625, 83415, USA.
| | - Kazuhiro Iwamatsu
- Department of Chemistry, Brookhaven National Laboratory, Upton, New York, 11973, USA
| | - Michael E Woods
- Advanced Technology of Molten Salts, Idaho National Laboratory, Idaho Falls, ID, P.O. Box 1625, 83415, USA
| | - Ruchi Gakhar
- Advanced Technology of Molten Salts, Idaho National Laboratory, Idaho Falls, ID, P.O. Box 1625, 83415, USA
| | - Bobby Layne
- Department of Chemistry, Brookhaven National Laboratory, Upton, New York, 11973, USA
| | - Andrew R Cook
- Department of Chemistry, Brookhaven National Laboratory, Upton, New York, 11973, USA
| | - Gregory P Horne
- Center for Radiation Chemistry Research, Idaho National Laboratory, Idaho Falls, ID, P.O. Box 1625, 83415, USA.
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Wang Y, Mezyk SP, McLachlan JR, Grimes TS, Zalupski PR, O'Bryan HMT, Cook AR, Abergel RJ, Horne GP. Radiolytic Evaluation of 3,4,3-LI(1,2-HOPO) in Aqueous Solutions. J Phys Chem B 2023; 127:3931-3938. [PMID: 37084416 DOI: 10.1021/acs.jpcb.3c01469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/23/2023]
Abstract
The octadentate hydroxypyridinone ligand 3,4,3-LI(1,2-HOPO) (abbreviated as HOPO) has been identified as a promising candidate for both chelation and f-element separation technologies, two applications that require optimal performance in radiation environments. However, the radiation robustness of HOPO is currently unknown. Here, we employ a combination of time-resolved (electron pulse) and steady-state (alpha self-radiolysis) irradiation techniques to elucidate the basic chemistry of HOPO and its f-element complexes in aqueous radiation environments. Chemical kinetics were measured for the reaction of HOPO and its Nd(III) ion complex ([NdIII(HOPO)]-) with key aqueous radiation-induced radical transients (eaq-, H• atom, and •OH and NO3• radicals). The reaction of HOPO with the eaq- is believed to proceed via reduction of the hydroxypyridinone moiety, while transient adduct spectra indicate that reactions with the H• atom and •OH and NO3• radicals proceeded by addition to HOPO's hydroxypyridinone rings, potentially allowing for the generation of an extensive suite of addition products. Complementary steady-state 241Am(III)-HOPO complex ([241AmIII(HOPO)]-) irradiations showed the gradual release of 241Am(III) ions with increasing alpha dose up to 100 kGy, although complete ligand destruction was not observed.
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Affiliation(s)
- Yufei Wang
- Department of Nuclear Engineering, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Center for Radiation Chemistry Research, Idaho National Laboratory, Idaho Falls, Idaho 83415, United States
| | - Stephen P Mezyk
- Department of Chemistry and Biochemistry, California State University Long Beach, Long Beach, California 90804, United States
| | - Jeffrey R McLachlan
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Travis S Grimes
- Center for Radiation Chemistry Research, Idaho National Laboratory, Idaho Falls, Idaho 83415, United States
| | - Peter R Zalupski
- Center for Radiation Chemistry Research, Idaho National Laboratory, Idaho Falls, Idaho 83415, United States
| | - Hailie M T O'Bryan
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Andrew R Cook
- Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Rebecca J Abergel
- Department of Nuclear Engineering, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Gregory P Horne
- Center for Radiation Chemistry Research, Idaho National Laboratory, Idaho Falls, Idaho 83415, United States
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Horne GP, Rotermund BM, Grimes TS, Sperling JM, Meeker DS, Zalupski PR, Beck N, Huffman ZK, Martinez DG, Beshay A, Peterman DR, Layne BH, Johnson J, Cook AR, Albrecht-Schönzart TE, Mezyk SP. Transient Radiation-Induced Berkelium(III) and Californium(III) Redox Chemistry in Aqueous Solution. Inorg Chem 2022; 61:10822-10832. [PMID: 35776877 DOI: 10.1021/acs.inorgchem.2c01106] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Despite the significant impact of radiation-induced redox reactions on the accessibility and lifetimes of actinide oxidation states, fundamental knowledge of aqueous actinide metal ion radiation chemistry is limited, especially for the late actinides. A quantitative understanding of these intrinsic radiation-induced processes is essential for investigating the fundamental properties of these actinides. We present here a picosecond electron pulse reaction kinetics study into the radiation-induced redox chemistry of trivalent berkelium (Bk(III)) and californium (Cf(III)) ions in acidic aqueous solutions at ambient temperature. New and first-of-a-kind, second-order rate coefficients are reported for the transient radical-induced reduction of Bk(III) and Cf(III) by the hydrated electron (eaq-) and hydrogen atom (H•), demonstrating a significant reactivity (up to 1011 M-1 s-1) indicative of a preference of these metals to adopt divalent states. Additionally, we report the first-ever second-order rate coefficients for the transient radical-induced oxidation of these elements by a reaction with hydroxyl (•OH) and nitrate (NO3•) radicals, which also exhibited fast reactivity (ca. 108 M-1 s-1). Transient Cf(II), Cf(IV), and Bk(IV) absorption spectra are also reported. Overall, the presented data highlight the existence of rich, complex, intrinsic late actinide radiation-induced redox chemistry that has the potential to influence the findings of other areas of actinide science.
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Affiliation(s)
- Gregory P Horne
- Center for Radiation Chemistry Research, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, Idaho 83415, United States
| | - Brian M Rotermund
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Travis S Grimes
- Center for Radiation Chemistry Research, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, Idaho 83415, United States
| | - Joseph M Sperling
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - David S Meeker
- Center for Radiation Chemistry Research, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, Idaho 83415, United States.,Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Peter R Zalupski
- Center for Radiation Chemistry Research, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, Idaho 83415, United States
| | - Nicholas Beck
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Zachary K Huffman
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Daniela Gomez Martinez
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Andrew Beshay
- Department of Chemistry and Biochemistry, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840-9507, United States
| | - Dean R Peterman
- Center for Radiation Chemistry Research, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, Idaho 83415, United States
| | - Bobby H Layne
- Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Jason Johnson
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Andrew R Cook
- Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Thomas E Albrecht-Schönzart
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Stephen P Mezyk
- Department of Chemistry and Biochemistry, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840-9507, United States
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Abstract
Ultrafast hole transfer from solvent radical cations produced by radiolysis with ∼10 ps, 9 MeV electron pulses to solutes in tetrahydrofuran (THF) was investigated. Because of rapid fragmentation of initially produced THF+•, solute radical cations are not expected and have not previously been reported. When 9,9-dihexyl-2,7-dibromofluorene (Br2F) at 5 to 1000 mM was used, Br2F+• with radiation chemical yields up to G = 2.23/100 eV absorbed was observed. While more than half of this was the result of direct solute ionization, the results highlight the importance of capturing holes from THF+• prior to solvation and fragmentation. The observed data show a time-resolution limited (15 ps) rise in transient absorption of Br2F+•, identical in form to reports of presolvated or dry electron capture in water and a few organic liquids, including THF. The results were thus interpreted with a similar formalism, finding C37 = 1.7 M, the concentration at which 37% of holes escape capture. The yield of solvent hole capture can be accounted for by the formation of solvent holes adjacent to solute molecules reacting faster than they can fragment; however, mechanisms such as delocalized holes or rapid hopping may play a role. Low temperature results find over two times more capture, supporting the speculation that if THF+• was longer lived, the yield of capture in under 15 ps would have been at least 2 times larger at 1 M Br2F, possibly capturing nearly all available holes from the solvent.
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Affiliation(s)
- Andrew R Cook
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973, United States
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Celis Barros C, Pilgrim CD, Cook AR, Mezyk SP, Grimes TS, Horne GP. Influence of uranyl complexation on the reaction kinetics of the dodecane radical cation with used nuclear fuel extraction ligands (TBP, DEHBA, and DEHiBA). Phys Chem Chem Phys 2021; 23:24589-24597. [PMID: 34710211 DOI: 10.1039/d1cp03797h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Specialized extractant ligands - such as tri-butyl phosphate (TBP), N,N-di-(2-ethylhexyl)butyramide (DEHBA), and N,N-di-2-ethylhexylisobutryamide (DEHiBA) - have been developed for the recovery of uranium from used nuclear fuel by reprocessing solvent extraction technologies. These ligands must function in the presence of an intense multi-component radiation field, and thus it is critical that their radiolytic behaviour be thoroughly evaluated. This is especially true for their metal complexes, where there is negligible information on the influence of complexation on radiolytic reactivity, despite the prevalence of metal complexes in used nuclear fuel reprocessing solvent systems. Here we present a kinetic investigation into the effect of uranyl (UO22+) complexation on the reaction kinetics of the dodecane radical cation (RH˙+) with TBP, DEHBA, and DEHiBA. Complexation had negligible effect on the reaction of RH˙+ with TBP, for which a second-order rate coefficient (k) of (1.3 ± 0.1) × 1010 M-1 s-1 was measured. For DEHBA and DEHiBA, UO22+ complexation afforded an increase in their respective rate coefficients: k(RH˙+ + [UO2(NO3)2(DEHBA)2]) = (2.5 ± 0.1) × 1010 M-1 s-1 and k(RH˙+ + [UO2(NO3)2(DEHiBA)2]) = (1.6 ± 0.1) × 1010 M-1 s-1. This enhancement with complexation is indicative of an alternative RH˙+ reaction pathway, which is more readily accessible for [UO2(NO3)2(DEHBA)2] as it exhibited a much larger kinetic enhancement than [UO2(NO3)2(DEHiBA)2], 2.6× vs. 1.4×, respectively. Complementary quantum mechanical calculations suggests that the difference in reaction kinetic enhancement between TBP and DEHBA/DEHiBA is attributed to a combination of reaction pathway (electron/hole transfer vs. proton transfer) energetics and electron density distribution, wherein attendant nitrate counter anions effectively 'shield' TBP from RH˙+ electron transfer processes.
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Affiliation(s)
- Cristian Celis Barros
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA.
| | - Corey D Pilgrim
- Center for Radiation Chemistry Research, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID, 83415, USA.
| | - Andrew R Cook
- Department of Chemistry, Brookhaven National Laboratory, Upton, New York, 11973, USA
| | - Stephen P Mezyk
- Department of Chemistry and Biochemistry, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach, California, 90840-9507, USA
| | - Travis S Grimes
- Center for Radiation Chemistry Research, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID, 83415, USA.
| | - Gregory P Horne
- Center for Radiation Chemistry Research, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID, 83415, USA.
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Wang CG, Li Z, Liu S, Ng CT, Marzuki M, Jeslyn Wong PS, Tan B, Lee A, Hui Lim CF, Bifani P, Fang Z, Ching Wong JC, Setoh YX, Yang YY, Mun CH, Fiona Phua SZ, Lim WQ, Lin L, Cook AR, Tanoto H, Ng LC, Singhal A, Leong YW, Loh XJ. N95 respirator decontamination: a study in reusability. Mater Today Adv 2021; 11:100148. [PMID: 34179746 PMCID: PMC8220445 DOI: 10.1016/j.mtadv.2021.100148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/20/2021] [Accepted: 04/21/2021] [Indexed: 05/23/2023]
Abstract
The coronavirus disease 2019 (COVID-19) pandemic had caused a severe depletion of the worldwide supply of N95 respirators. The development of methods to effectively decontaminate N95 respirators while maintaining their integrity is crucial for respirator regeneration and reuse. In this study, we systematically evaluated five respirator decontamination methods using vaporized hydrogen peroxide (VHP) or ultraviolet (254 nm wavelength, UVC) radiation. Through testing the bioburden, filtration, fluid resistance, and fit (shape) of the decontaminated respirators, we found that the decontamination methods using BioQuell VHP, custom VHP container, Steris VHP, and Sterrad VHP effectively inactivated Cardiovirus (3-log10 reduction) and bacteria (6-log10 reduction) without compromising the respirator integrity after 2-15 cycles. Hope UVC system was capable of inactivating Cardiovirus (3-log10 reduction) but exhibited relatively poorer bactericidal activity. These methods are capable of decontaminating 10-1000 respirators per batch with varied decontamination times (10-200 min). Our findings show that N95 respirators treated by the previously mentioned decontamination methods are safe and effective for reuse by industry, laboratories, and hospitals.
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Affiliation(s)
- C-G Wang
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A∗STAR), 2 Fusionopolis Way, Innovis, No. 08-03, 138634, Singapore
| | - Z Li
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A∗STAR), 2 Fusionopolis Way, Innovis, No. 08-03, 138634, Singapore
| | - S Liu
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A∗STAR), 2 Fusionopolis Way, Innovis, No. 08-03, 138634, Singapore
| | - C T Ng
- Environmental Health Institute, National Environment Agency (NEA), 11 Biopolis Way No.06-05/08 Helios Block, 138667, Singapore
| | - M Marzuki
- A∗STAR Infectious Diseases Labs, Agency for Science, Technology and Research (A∗STAR), 8A Biomedical Grove, 138648, Singapore
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A∗STAR), 8A Biomedical Grove, 138648, Singapore
| | - P S Jeslyn Wong
- Environmental Health Institute, National Environment Agency (NEA), 11 Biopolis Way No.06-05/08 Helios Block, 138667, Singapore
| | - B Tan
- A∗STAR Infectious Diseases Labs, Agency for Science, Technology and Research (A∗STAR), 8A Biomedical Grove, 138648, Singapore
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A∗STAR), 8A Biomedical Grove, 138648, Singapore
| | - A Lee
- A∗STAR Infectious Diseases Labs, Agency for Science, Technology and Research (A∗STAR), 8A Biomedical Grove, 138648, Singapore
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A∗STAR), 8A Biomedical Grove, 138648, Singapore
| | - C F Hui Lim
- A∗STAR Infectious Diseases Labs, Agency for Science, Technology and Research (A∗STAR), 8A Biomedical Grove, 138648, Singapore
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A∗STAR), 8A Biomedical Grove, 138648, Singapore
| | - P Bifani
- A∗STAR Infectious Diseases Labs, Agency for Science, Technology and Research (A∗STAR), 8A Biomedical Grove, 138648, Singapore
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A∗STAR), 8A Biomedical Grove, 138648, Singapore
| | - Z Fang
- Environmental Health Institute, National Environment Agency (NEA), 11 Biopolis Way No.06-05/08 Helios Block, 138667, Singapore
| | - J C Ching Wong
- Environmental Health Institute, National Environment Agency (NEA), 11 Biopolis Way No.06-05/08 Helios Block, 138667, Singapore
| | - Y X Setoh
- Environmental Health Institute, National Environment Agency (NEA), 11 Biopolis Way No.06-05/08 Helios Block, 138667, Singapore
| | - Y Y Yang
- Institute of Bioengineering and Bioimaging, Agency for Science, Technology and Research (A∗STAR), 31 Biopolis Way, Nanos, 138669, Singapore
| | - C H Mun
- DSO National Laboratories, 12 Science Park Dr, 118225, Singapore
| | - S Z Fiona Phua
- DSO National Laboratories, 12 Science Park Dr, 118225, Singapore
| | - W Q Lim
- DSO National Laboratories, 12 Science Park Dr, 118225, Singapore
| | - L Lin
- ST Engineering Aerospace Engines Pte Ltd, 501 Airport Rd, 539931, Singapore
| | - A R Cook
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, 12 Science Drive 2, 117549, Singapore
| | - H Tanoto
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A∗STAR), 2 Fusionopolis Way, Innovis, No. 08-03, 138634, Singapore
| | - L-C Ng
- Environmental Health Institute, National Environment Agency (NEA), 11 Biopolis Way No.06-05/08 Helios Block, 138667, Singapore
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| | - A Singhal
- A∗STAR Infectious Diseases Labs, Agency for Science, Technology and Research (A∗STAR), 8A Biomedical Grove, 138648, Singapore
- Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A∗STAR), 8A Biomedical Grove, 138648, Singapore
| | - Y W Leong
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A∗STAR), 2 Fusionopolis Way, Innovis, No. 08-03, 138634, Singapore
| | - X J Loh
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A∗STAR), 2 Fusionopolis Way, Innovis, No. 08-03, 138634, Singapore
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12
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Horne GP, Grimes TS, Zalupski PR, Meeker DS, Albrecht-Schönzart TE, Cook AR, Mezyk SP. Curium(iii) radiation-induced reaction kinetics in aqueous media. Dalton Trans 2021; 50:10853-10859. [PMID: 34296716 DOI: 10.1039/d1dt01268a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Insight into the effects of radiolytic processes on the actinides is critical for advancing our understanding of their solution chemistry because the behaviour of these elements cannot be easily separated from the influence of their inherent radiation field. However, minimal information exists on the radiation-induced redox behaviour of curium (Cm), a key trivalent transuranic element present in used nuclear fuel and frequently used as an alpha radiation source. Here we present a kinetic study on the aqueous redox reactions of Cm(iii) with radicals generated through the radiolysis of aqueous media. In particular, we probe reaction kinetics in nitric acid solutions that are used as the aqueous phase component of used nuclear fuel reprocessing solvent systems. Second-order rate coefficients (k) were measured for the reaction of Cm(iii) with the hydrated electron (eaq-, k = (1.25 ± 0.03) × 1010 M-1 s-1), hydrogen atom (H˙, k = (5.16 ± 0.37) × 108 M-1 s-1), hydroxyl radical (˙OH, k = (1.69 ± 0.24) × 109 M-1 s-1), and nitrate radical (NO3˙, k = (4.83 ± 0.09) × 107 M-1 s-1). Furthermore, the first-ever Cm(ii) absorption spectrum (300-700 nm) is also reported. These kinetic data dispel the status quo notion of Cm(iii) possessing little to no redox chemistry in aqueous solution, and suggest that the resulting Cm(ii) and Cm(iv) transients could exist in irradiated aqueous solutions and be available to undergo subsequent redox chemistry with other solutes.
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Affiliation(s)
- Gregory P Horne
- Idaho National Laboratory, Center for Radiation Chemistry Research, Idaho Falls, ID, P.O. Box 1625, 83415, USA.
| | - Travis S Grimes
- Idaho National Laboratory, Center for Radiation Chemistry Research, Idaho Falls, ID, P.O. Box 1625, 83415, USA.
| | - Peter R Zalupski
- Idaho National Laboratory, Center for Radiation Chemistry Research, Idaho Falls, ID, P.O. Box 1625, 83415, USA.
| | - David S Meeker
- Idaho National Laboratory, Center for Radiation Chemistry Research, Idaho Falls, ID, P.O. Box 1625, 83415, USA. and Florida State University, Department of Chemistry and Biochemistry, Tallahassee, FL 32306, USA
| | | | - Andrew R Cook
- Department of Chemistry, Brookhaven National Laboratory, Upton, New York, 11973, USA
| | - Stephen P Mezyk
- Department of Chemistry and Biochemistry, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach California 90840-9507, USA.
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13
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Khanna RK, Hage A, Cook AR, Zuber K, Audren F, Vignal-Clermont C, Hage R. Microcystic macular degeneration in autosomal hereditary optic neuropathies: A cross-sectional retrospective study. J Fr Ophtalmol 2021; 44:995-1000. [PMID: 34147274 DOI: 10.1016/j.jfo.2020.10.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/22/2020] [Accepted: 10/11/2020] [Indexed: 10/21/2022]
Abstract
OBJECTIVE Patients with autosomal optic neuropathies (AON) may develop microcystic macular degeneration (MMD), observed on retinal optical coherence tomography (OCT) examination. This study aimed to report the prevalence of MMD in AON patients and to assess the consequences of MMD on retinal architecture. METHODS Retrospective single-center study conducted between 2001 and 2018. Patients affected by AON secondary to OPA1 or WFS1 gene mutations were included. The following data were collected: visual acuity, macular volume, vitreomacular interface and presence or absence of MMD. RESULTS Forty-two subjects (34 OPA1, 8 WFS1) were included. MMD was found in 12 (29%) patients, i.e. 6 of the 8 WFS1 patients (75%) and 6 of the 34 OPA1 patients (17%). In cases with MMD, total retinal volume was greater (P=0.02) in accordance with thickening of the inner nuclear layer (P<0.001). WFS1 subjects had the highest total retinal volume (P=0.01), in relation to a thickening of the inner plexiform layer (P=0.02), inner nuclear layer (P<0.001) and outer plexiform layer (P=0.002). MMD was significantly associated with the WFS1 mutation (P<0.001). No significant association was found between the presence of vitreomacular adhesion and MMD. CONCLUSION MMD was found in 29% of patients affected by AON and was more frequent in cases with a WFS1 gene mutation. MMD appears to be related to primary ganglion cell degeneration and Müller cell dysfunction. The vitreomacular interface does not appear to play a role in the occurrence of MMD.
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Affiliation(s)
- R K Khanna
- Department of Neuro-ophthalmology, Fondation Adolphe de Rothschild Hospital, Paris, France; Department of Ophthalmology, Centre Hospitalier Régional Universitaire, Bretonneau Hospital, Tours, France.
| | - A Hage
- Department of Neuro-ophthalmology, Fondation Adolphe de Rothschild Hospital, Paris, France
| | - A R Cook
- Department of Ophthalmology, Centre Hospitalier Régional Universitaire, Bretonneau Hospital, Tours, France
| | - K Zuber
- Clinical Research Unit, Fondation Adolphe de Rothschild Hospital, Paris, France
| | - F Audren
- Department of Neuro-ophthalmology, Fondation Adolphe de Rothschild Hospital, Paris, France
| | - C Vignal-Clermont
- Department of Neuro-ophthalmology, Fondation Adolphe de Rothschild Hospital, Paris, France; Centre for Clinical Research Investigations, Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Paris, France
| | - R Hage
- Department of Neuro-ophthalmology, Fondation Adolphe de Rothschild Hospital, Paris, France; Centre for Clinical Research Investigations, Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Paris, France
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14
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Stevens AJ, Campbell JL, Travis KZ, Clewell HJ, Hinderliter PM, Botham PA, Cook AR, Minnema DJ, Wolf DC. Paraquat pharmacokinetics in primates and extrapolation to humans. Toxicol Appl Pharmacol 2021; 417:115463. [PMID: 33631232 DOI: 10.1016/j.taap.2021.115463] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 02/12/2021] [Accepted: 02/14/2021] [Indexed: 11/28/2022]
Abstract
By extending our Paraquat (PQ) work to include primates we have implemented a modelling and simulation strategy that has enabled PQ pharmacokinetic data to be integrated into a single physiologically based pharmacokinetic (PBPK) model that enables more confident extrapolation to humans. Because available data suggested there might be differences in PQ kinetics between primates and non-primates, a radiolabelled study was conducted to characterize pharmacokinetics and excretion in Cynomolgus monkeys. Following single intravenous doses of 0.01 or 0.1 mg paraquat dichloride/kg bw, plasma PQ concentration-time profiles were dose-proportional. Excretion up to 48 h (predominantly urinary) was 82.9%, with ca. 10% remaining unexcreted. In vitro blood binding was similar across Cynomolgus monkeys, humans and rat. Our PBPK model for the rat, mouse and dog, employing a single set of PQ-specific parameters, was scaled to Cynomolgus monkeys and well represented the measured plasma concentration-time profiles over 14 days. Addition of a cartilage compartment to the model better captured the percent remaining in the monkeys at 48 h, whilst having negligible effect on model predictions for the other species. The PBPK model performed well for all four species, demonstrating there is little difference in PQ kinetics between non-primates and primates enabling a more confident extrapolation to humans. Scaling of the PBPK model to humans, with addition of a human-specific dermal submodel based on in vitro human dermal absorption data, provides a valuable tool that could be employed in defining internal dosimetry to complement human health risk assessments.
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Affiliation(s)
- Alexander J Stevens
- Syngenta Ltd, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK.
| | - Jerry L Campbell
- Ramboll Environment and Health Consulting, 3214 Charles B. Root Wynd Suite 130, Raleigh, NC 27612, USA.
| | - Kim Z Travis
- Syngenta Ltd, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK.
| | - Harvey J Clewell
- Ramboll Environment and Health Consulting, 3214 Charles B. Root Wynd Suite 130, Raleigh, NC 27612, USA.
| | | | - Philip A Botham
- Syngenta Ltd, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK.
| | - Andrew R Cook
- Syngenta Ltd, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK.
| | - Daniel J Minnema
- Syngenta Crop Protection LLC, P.O. Box 18300, Greensboro, NC, USA.
| | - Douglas C Wolf
- Syngenta Crop Protection LLC, Research Triangle Park, NC 27709, USA.
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15
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Campbell JL, Travis KZ, Clewell HJ, Stevens AJ, Hinderliter PM, Andersen ME, Botham PA, Cook AR, Minnema DJ, Wolf DC. Integration of paraquat pharmacokinetic data across species using PBPK modelling. Toxicol Appl Pharmacol 2021; 417:115462. [PMID: 33631233 DOI: 10.1016/j.taap.2021.115462] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 02/12/2021] [Accepted: 02/14/2021] [Indexed: 11/15/2022]
Abstract
Paraquat dichloride (PQ) is a non-selective herbicide which has been the subject of numerous toxicology studies over more than 50 years. This paper describes the development of a physiologically-based pharmacokinetic (PBPK) model of PQ kinetics for the rat, mouse and dog, firstly to aid the interpretation of studies in which no kinetic measurements were made, and secondly to enable the future extension of the model to humans. Existing pharmacokinetic data were used to develop a model for the rat and mouse. Simulations with this preliminary model were then used to identify key data gaps and to design a new blood binding study to reduce uncertainty in critical aspects of the model. The new data provided evidence to support the model structure, and its predictive performance was then assessed against dog and rat datasets not used in model development. The PQ-specific model parameters are the same for all three species, with only the physiological parameters varying between species. This consistency across species provides a strong basis for extrapolation to other species, as demonstrated here for the dog. The model enables a wide range of PQ data to be linked together to provide a broad understanding of PQ pharmacokinetics in rodents and the dog, showing that the key aspects of PQ kinetics in these species are understood and adequately encapsulated within the model.
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Affiliation(s)
- Jerry L Campbell
- Ramboll Environment and Health Consulting, 3214 Charles B. Root Wynd Suite 130, Raleigh, NC 27612, USA.
| | - Kim Z Travis
- Syngenta Ltd, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK.
| | - Harvey J Clewell
- Ramboll Environment and Health Consulting, 3214 Charles B. Root Wynd Suite 130, Raleigh, NC 27612, USA.
| | - Alexander J Stevens
- Syngenta Ltd, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK.
| | | | - Melvin E Andersen
- Andersen ToxConsulting LLC, 424 Granite Lake CT, Denver, NC 28037, USA
| | - Philip A Botham
- Syngenta Ltd, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK.
| | - Andrew R Cook
- Syngenta Ltd, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK.
| | - Daniel J Minnema
- Syngenta Crop Protection LLC, P.O. Box 18300, Greensboro, NC, USA.
| | - Douglas C Wolf
- Syngenta Crop Protection LLC, Research Triangle Park, NC 27709, USA.
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16
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Toigawa T, Peterman DR, Meeker DS, Grimes TS, Zalupski PR, Mezyk SP, Cook AR, Yamashita S, Kumagai Y, Matsumura T, Horne GP. Radiation-induced effects on the extraction properties of hexa- n-octylnitrilo-triacetamide (HONTA) complexes of americium and europium. Phys Chem Chem Phys 2021; 23:1343-1351. [PMID: 33367347 DOI: 10.1039/d0cp05720g] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The candidate An(iii)/Ln(iii) separation ligand hexa-n-octylnitrilo-triacetamide (HONTA) was irradiated under envisioned SELECT (Solvent Extraction from Liquid waste using Extractants of CHON-type for Transmutation) process conditions (n-dodecane/0.1 M HNO3) using a solvent test loop in conjunction with cobalt-60 gamma irradiation. The extent of HONTA radiolysis and complementary degradation product formation was quantified by HPLC-ESI-MS/MS. Further, the impact of HONTA radiolysis on process performance was evaluated by measuring the change in 243Am and 154Eu distribution ratios as a function of absorbed gamma dose. HONTA was found to decay exponentially with increasing dose, affording a dose coefficient of d = (4.48 ± 0.19) × 10-3 kGy-1. Multiple degradation products were detected by HPLC-ESI-MS/MS with dioctylamine being the dominant quantifiable species. Both 243Am and 154Eu distribution ratios exhibited an induction period of ∼70 kGy for extraction (0.1 M HNO3) and back-extraction (4.0 M HNO3) conditions, after which both values decreased with absorbed dose. The decrease in distribution ratios was attributed to a combination of the destruction of HONTA and ingrowth of dioctylamine, which is capable of interfering in metal ion complexation. The loss of HONTA with absorbed gamma dose was predominantly attributed to its reaction with the n-dodecane radical cation (R˙+). These R˙+ reaction kinetics were measured for HONTA and its 241Am and 154Eu complexes using picosecond pulsed electron radiolysis techniques. All three second-order rate coefficients (k) were essentially diffusion limited in n-dodecane indicating a significant reaction pathway: k(HONTA + R˙+) = (7.6 ± 0.8) × 109 M-1 s-1, k(Am(HONTA)2 + R˙+) = (7.1 ± 0.7) × 1010 M-1 s-1, and k(Eu(HONTA)2 + R˙+) = (9.5 ± 0.5) × 1010 M-1 s-1. HONTA-metal ion complexation afforded an order-of-magnitude increase in rate coefficient. Nanosecond time-resolved measurements showed that both direct and indirect HONTA radiolysis yielded the short-lived (<100 ns) HONTA radical cation and a second long-lived (μs) species identified as the HONTA triplet excited state. The latter was confirmed by a series of oxygen quenching picosecond pulsed electron measurements, affording a quenching rate coefficient of k(3[HONTA]* + O2) = 2.2 × 108 M-1 s-1. Overall, both the HONTA radical cation and triplet excited state are important precursors to the suite of measured HONTA degradation products.
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Affiliation(s)
- Tomohiro Toigawa
- Japan Atomic Energy Agency, Nuclear Science and Engineering Center, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan.
| | - Dean R Peterman
- Center for Radiation Chemistry Research, Idaho National Laboratory, 1955 N. Freemont Ave., Idaho Falls, 83415, USA.
| | - David S Meeker
- Center for Radiation Chemistry Research, Idaho National Laboratory, 1955 N. Freemont Ave., Idaho Falls, 83415, USA.
| | - Travis S Grimes
- Center for Radiation Chemistry Research, Idaho National Laboratory, 1955 N. Freemont Ave., Idaho Falls, 83415, USA.
| | - Peter R Zalupski
- Center for Radiation Chemistry Research, Idaho National Laboratory, 1955 N. Freemont Ave., Idaho Falls, 83415, USA.
| | - Stephen P Mezyk
- Department of Chemistry and Biochemistry, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840-9507, USA
| | - Andrew R Cook
- Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Shinichi Yamashita
- University of Tokyo, Nuclear Professional School, School of Engineering, 2-22 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1188, Japan
| | - Yuta Kumagai
- Japan Atomic Energy Agency, Nuclear Science and Engineering Center, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan.
| | - Tatsuro Matsumura
- Japan Atomic Energy Agency, Nuclear Science and Engineering Center, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195, Japan.
| | - Gregory P Horne
- Center for Radiation Chemistry Research, Idaho National Laboratory, 1955 N. Freemont Ave., Idaho Falls, 83415, USA.
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17
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Cook AR, Girimonti A, Sreearunothai P, Asaoka S, Miller JR. Dynamic broadening alters triplet extinction coefficients in fluorene oligomers and polymers. J Chem Phys 2020; 152:024901. [DOI: 10.1063/1.5132798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Andrew R. Cook
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Anthony Girimonti
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | | | - Sadayuki Asaoka
- Department of Materials Science and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - John R. Miller
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973, USA
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18
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Bird MJ, Cook AR, Zamadar M, Asaoka S, Miller JR. Pushing the limits of the electrochemical window with pulse radiolysis in chloroform. Phys Chem Chem Phys 2020; 22:14660-14670. [PMID: 32573579 DOI: 10.1039/d0cp01948h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Pulse radiolysis (PR) enables the full redox window of a solvent to be accessed, as it does not require electrodes or electrolyte which limit the potentials accessible in voltammetry measurements. PR in chloroform has the additional possibility to enable reaching highly positive potentials because of its large ionization potential (IP). PR experiments demonstrated the formation of the (deuterated) chloroform radical cation CDCl3+˙, identifying it as the source of the broad absorption in the visible part of the spectrum. Results indicated that solutes with a redox potential up to +3.7 V vs. Fc/Fc+ can be oxidized by CDCl3+˙, which is far beyond what is possible with electrochemical techniques. Oxidation is not efficient because of rapid geminate recombination with chloride counterions, but also due to rapid decomposition of CDCl3+˙ which limits the yield of otherwise longer-lived free ions. The rapid, 6 ± 3 ns, decomposition, confirmed by two independent experiments, means that a solute must be present at a concentration >100 mM to capture >90% of the free holes formed. Addition of ethene removes the broad, overlapping absorptions from ubiquitous (chlorine atom, solute) complexes created by PR in halogenated solvents enabling clear observation of solute cations. The results also unravel the complex radiation chemistry of chloroform including the large reported value G(-CHCl3) = 12 molecules/100 eV for the decomposition of chloroform molecules.
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Affiliation(s)
- Matthew J Bird
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11793, USA.
| | - Andrew R Cook
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11793, USA.
| | - Matibur Zamadar
- Department of Chemistry and Biochemistry, Stephen F. Austin State University, Nacogdoches, Texas 75962-3006, USA
| | - Sadayuki Asaoka
- Department of Biomolecular Engineering, Kyoto Institute of Technology, Matsugaskaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - John R Miller
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11793, USA.
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19
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Horne GP, Zarzana CA, Rae C, Cook AR, Mezyk SP, Zalupski PR, Wilden A, Mincher BJ. Does addition of 1-octanol as a phase modifier provide radical scavenging radioprotection for N,N,N′,N′-tetraoctyldiglycolamide (TODGA)? Phys Chem Chem Phys 2020; 22:24978-24985. [DOI: 10.1039/d0cp04310a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The incorporation of 1-octanol as a phase modifier in TODGA solvent system formulations promotes TODGA radiolysis under organic-only conditions, and radioprotection under biphasic nitric acid conditions.
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Affiliation(s)
- Gregory P. Horne
- Center for Radiation Chemistry Research
- Idaho National Laboratory
- Idaho Falls
- USA
| | | | - Cathy Rae
- Center for Radiation Chemistry Research
- Idaho National Laboratory
- Idaho Falls
- USA
| | - Andrew R. Cook
- Department of Chemistry
- Brookhaven National Laboratory
- New York
- USA
| | - Stephen P. Mezyk
- Department of Chemistry and Biochemistry
- California State University Long Beach
- Long Beach California
- USA
| | - Peter R. Zalupski
- Center for Radiation Chemistry Research
- Idaho National Laboratory
- Idaho Falls
- USA
| | - Andreas Wilden
- Forschungszentrum Jülich GmbH
- Institut für Energie- und Klimaforschung -Nukleare Entsorgung und Reaktorsicherheit- (IEK-6)
- 52428 Jülich
- Germany
| | - Bruce J. Mincher
- Center for Radiation Chemistry Research
- Idaho National Laboratory
- Idaho Falls
- USA
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20
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Miller JR, Cook AR, Šimková L, Pospíšil L, Ludvík J, Michl J. The Impact of Huge Structural Changes on Electron Transfer and Measurement of Redox Potentials: Reduction of ortho-12-Carborane. J Phys Chem B 2019; 123:9668-9676. [PMID: 31626548 DOI: 10.1021/acs.jpcb.9b08151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A massive structural change accompanies electron capture by the 1,2-dicarba-closo-dodecaborane cage molecule (1). Bimolecular electron transfer (ET) by pulse radiolysis found a reduction potential of E0 = -1.92 V vs Fc+/0 for 1 and rate constants that slowed greatly for ET to or from 1 when the redox partner had a potential near this E0. Similarly, two electrochemical techniques could detect no current at potentials near E0, finding instead peaks or polarographic waves near -3.1 V, which is 1.2 V more negative than E0. Voltammetry could determine rate constants, but only near -3.1 V. DigiSim simulations can describe the irreversible voltammograms but require electrochemical rate constants near 1 × 10-10 cm/s at E0, a factor of 10-10 relative to molecules undergoing facile ET. This factor of 10-10 compared to ∼10-5 for bimolecular ET presents a puzzle. This puzzle can be understood as a manifestation of one of the "Frumkin Effects" in which only part of the applied voltage is available to drive ET at the electrode.
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Affiliation(s)
- John R Miller
- Chemistry Division , Brookhaven National Laboratory , Upton , New York 11973 , United States
| | - Andrew R Cook
- Chemistry Division , Brookhaven National Laboratory , Upton , New York 11973 , United States
| | - Ludmila Šimková
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , Dolejškova 3 , Prague 8 , CZ-18223 , Czech Republic
| | - Lubomír Pospíšil
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , Dolejškova 3 , Prague 8 , CZ-18223 , Czech Republic
| | - Jiří Ludvík
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , Dolejškova 3 , Prague 8 , CZ-18223 , Czech Republic
| | - Josef Michl
- Department of Chemistry , University of Colorado , Boulder , Colorado 80309-0215 , United States.,Institute of Organic Chemistry and Biochemistry , Czech Academy of Sciences , Flemingovo nam. 2 , Prague 6 , CZ-16610 , Czech Republic
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21
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Pang L, Zhao X, Dickens BL, Lim JT, Cook AR, Netea MG, Donnelly JP, Herbrecht R, Johnson EM, Maertens JA, Kullberg BJ, Troke PF, Marr KA, Chai LYA. Using routine blood parameters to anticipate clinical outcomes in invasive aspergillosis. Clin Microbiol Infect 2019; 26:781.e1-781.e8. [PMID: 31669427 DOI: 10.1016/j.cmi.2019.10.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 10/03/2019] [Accepted: 10/15/2019] [Indexed: 12/29/2022]
Abstract
OBJECTIVE In invasive aspergillosis (IA), monitoring response to antifungal treatment is challenging. We aimed to explore if routine blood parameters help to anticipate outcomes following IA. METHODS Post hoc secondary analysis of two multicenter randomized trials was performed. The Global Comparative Aspergillosis Study (GCA, n = 123) and the Combination Antifungal Study (CAS, n = 251) constituted the discovery and validation cohorts respectively. The outcome measures were response to treatment and survival to 12 weeks. Interval platelet, galactomannan index (GMI) and C-reactive protein (CRP) levels prior and during antifungal treatment were analysed using logistic regression, Kaplan-Meier survival and receiver operating characteristic (ROC) analyses. RESULTS The 12-week survival was 70.7% and 63.7% for the GCA and CAS cohorts respectively. In the GCA cohort, every 10 × 109/L platelet count increase at week 2 and 4 improved 12-week survival odds by 6-18% (odds ratio (OR) 1.06-1.18, 95% confidence interval (CI) 1.02-1.33). Survival odds also improved 13% with every 10 mg/dL CRP drop at week 1 and 2 (OR 0.87, 95% CI 0.78-0.97). In the CAS cohort, week 2 platelet count was also associated with 12-week survival with 10% improved odds for every 10 × 109/L platelet increase (OR, 1.10, 95% CI 1.04-1.15). A GMI drop of 0.1 unit was additionally found to increase the odds of treatment response by 3% at the baseline of week 0 (OR 0.97, 95% CI 0.95-0.99). Week 2 platelet and CRP levels performed better than GMI on ROC analyses for survival (area under ROC curve 0.76, 0.87 and 0.67 respectively). A baseline platelet count higher than 30 × 109/L clearly identified patients with >75% survival probability. CONCLUSIONS Higher serial platelets were associated with overall survival while GMI trends were linked to IA treatment response. Routine and simple laboratory indices may aid follow-up of response in IA patients.
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Affiliation(s)
- L Pang
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - X Zhao
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - B L Dickens
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - J T Lim
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - A R Cook
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - M G Netea
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands
| | - J P Donnelly
- Department of Hematology, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - R Herbrecht
- Department of Oncology and Hematology, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - E M Johnson
- Mycology Reference Laboratory, Public Health England National Infection Services, Bristol, UK
| | - J A Maertens
- University Hospitals Leuven, Campus Gasthuisberg, Leuven, Belgium
| | - B J Kullberg
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands
| | | | - K A Marr
- Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - L Y A Chai
- Division of Infectious Diseases, University Medicine Cluster, National University Health System, Singapore and Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
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22
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Chen C, Lim JT, Chia NC, Wang L, Tysinger B, Zissimopolous J, Chong MZ, Wang Z, Koh GC, Yuan JM, Tan KB, Chia KS, Cook AR, Malhotra R, Chan A, Ma S, Ng TP, Koh WP, Goldman DP, Yoong J. The Long-Term Impact of Functional Disability on Hospitalization Spending in Singapore. J Econ Ageing 2019; 14:100193. [PMID: 31857943 PMCID: PMC6922027 DOI: 10.1016/j.jeoa.2019.02.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Singapore is one of the fastest-aging populations due to increased life expectancy and lowered fertility. Lifestyle changes increase the burden of chronic diseases and disability. These have important implications for social protection systems. The goal of this paper is to model future functional disability and healthcare expenditures based on current trends. To project the health, disability and hospitalization spending of future elders, we adapted the Future Elderly Model (FEM) to Singapore. The FEM is a dynamic Markov microsimulation model developed in the US. Our main source of population data was the Singapore Chinese Health Study (SCHS) consisting of 63,000 respondents followed up over three waves from 1993 to 2010. The FEM model enables us to investigate the effects of disability compounded over the lifecycle and hospitalization spending, while adjusting for competing risk of multi-comorbidities. Results indicate that by 2050, 1 in 6 elders in Singapore will have at least one ADL disability and 1 in 3 elders will have at least one IADL disability, an increase from 1 in 12 elders and 1 in 5 elders respectively in 2014. The highest prevalence of functional disability will be in those aged 85 years and above. Lifetime hospitalization spending of elders aged 55 and above is US$24,400 (30.2%) higher among people with functional disability compared to those without disability. Policies that successfully tackle diabetes and promote healthy living may reduce or delay the onset of disability, leading to potential saving. In addition, further technological improvements may reduce the financial burden of disability.
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Affiliation(s)
- C Chen
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
- Schaeffer Center for Health Policy and Economics, University of Southern California, USA
| | - JT Lim
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - NC Chia
- Department of Economics, National University of Singapore, Singapore
| | - L Wang
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - B Tysinger
- Schaeffer Center for Health Policy and Economics, University of Southern California, USA
| | - J Zissimopolous
- Schaeffer Center for Health Policy and Economics, University of Southern California, USA
| | - MZ Chong
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - Z Wang
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - GC Koh
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - JM Yuan
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Division of Cancer Control and Population Sciences, UPMC Hillman Cancer Center, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - KB Tan
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
- Policy Research and Economics Office, Ministry of Health, Singapore
| | - KS Chia
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - AR Cook
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
- Health Services and Systems Research, Duke-NUS Medical School, Singapore
| | - R Malhotra
- Health Services and Systems Research, Duke-NUS Medical School, Singapore
- Centre for Ageing Research and Education, Duke-NUS Medical School, Singapore
| | - A Chan
- Health Services and Systems Research, Duke-NUS Medical School, Singapore
- Centre for Ageing Research and Education, Duke-NUS Medical School, Singapore
| | - S Ma
- Epidemiology & Disease Control Division, Ministry of Health, Singapore
| | - TP Ng
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - WP Koh
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
- Health Services and Systems Research, Duke-NUS Medical School, Singapore
| | - DP Goldman
- Schaeffer Center for Health Policy and Economics, University of Southern California, USA
| | - J Yoong
- Center for Economic and Social Research, University of Southern California, USA
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23
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Abstract
The mobility of charges on conjugated polymers is a fundamentally important feature of these materials, but most fall far short of transport that might lead one to call them "molecular wires". A commonly identified bottleneck is flexible dihedral angles between repeat units. Here we find a very high mobility, μ > 86 cm2/(V s), for electrons attached to polyfluorene polymers in isooctane, despite the presence of varied dihedral angles. The present data suggest that interactions with the surrounding medium may be a principal determinant of charge mobility.
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Affiliation(s)
- Andrew R Cook
- Chemistry Department , Brookhaven National Laboratory , Upton, New York 11973 , United States
| | - Sadayuki Asaoka
- Department of Materials Science and Engineering , Kyoto Institute of Technology , Matsugasaki, Sakyo-ku, Kyoto 606-8585 , Japan
| | - Xiang Li
- Chemistry Department , Brookhaven National Laboratory , Upton, New York 11973 , United States
| | - John R Miller
- Chemistry Department , Brookhaven National Laboratory , Upton, New York 11973 , United States
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24
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Horne GP, Kiddle JJ, Zarzana CA, Rae C, Peller JR, Cook AR, Mezyk SP, Mincher BJ. 31P NMR study of the activated radioprotection mechanism of octylphenyl-N,N-diisobutylcarbamoylmethyl phosphine oxide (CMPO) and analogues. Dalton Trans 2019; 48:11547-11555. [DOI: 10.1039/c9dt01950b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Complexation of nitric acid by ligands containing conjugated aromatic phosphine oxide functionalities affords activated radioprotection through quenching n-dodecane excited states originating from gamma radiolysis.
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Affiliation(s)
- Gregory P. Horne
- Idaho National Laboratory
- Center for Radiation Chemistry Research
- Idaho Falls
- 83415, USA
| | - James J. Kiddle
- Western Michigan University
- Department of Chemistry
- Kalamazoo
- USA
| | | | - Cathy Rae
- Idaho National Laboratory
- Center for Radiation Chemistry Research
- Idaho Falls
- 83415, USA
| | | | - Andrew R. Cook
- Brookhaven National Laboratory
- Department of Chemistry
- Upton
- USA
| | - Stephen P. Mezyk
- California State University Long Beach
- Department of Chemistry and Biochemistry
- Long Beach
- USA
| | - Bruce J. Mincher
- Idaho National Laboratory
- Center for Radiation Chemistry Research
- Idaho Falls
- 83415, USA
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25
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Meignan P, Binet A, Cook AR, Lardy H, Captier G. Fetal median sacral artery anatomy study by micro-CT imaging. Surg Radiol Anat 2018; 40:735-741. [PMID: 29713738 DOI: 10.1007/s00276-018-2032-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 04/17/2018] [Indexed: 01/05/2023]
Abstract
PURPOSE The median sacral artery (MSA) is the termination of the dorsal aorta, which undergoes a complex regression and remodeling process during embryo and fetal development. The MSA contributes to the pelvic vascularization and may be injured during pelvic surgery. The embryological steps of MSA development, anastomosis formation and anatomical variations are linked, but not fully understood. METHODS The pelvic vascularization and more precisely the MSA of a human fetus at 22 weeks of gestation (GW) were studied using micro-CT imaging. Image treatment included arterial segmentations and 3D visualization. RESULTS At 22 GW, the MSA was a well-developed straight artery in front of the sacrum and was longer than the abdominal aorta. Anastomoses between the MSA and the internal pudendal arteries and the superior rectal artery were detected. No evidence was found for the existence of a coccygeal glomus with arteriovenous anastomosis. CONCLUSIONS Micro-CT imaging and 3D visualization helped us understand the MSA central role in pelvic vascularization through the ilio-aortic anastomotic system. It is essential to know this anastomotic network to treat pathological conditions, such as sacrococcygeal teratomas and parasitic ischiopagus twins (for instance, fetus in fetu and twin-reversed arterial perfusion sequence).
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Affiliation(s)
- P Meignan
- Service de chirurgie pédiatrique viscérale, urologique, plastique et brûlés, CHRU Tours, Tours, France.
| | - A Binet
- Service de chirurgie pédiatrique viscérale, urologique, plastique et brûlés, CHRU Tours, Tours, France
| | - A R Cook
- Service de chirurgie pédiatrique viscérale, urologique, plastique et brûlés, CHRU Tours, Tours, France
| | - H Lardy
- Service de chirurgie pédiatrique viscérale, urologique, plastique et brûlés, CHRU Tours, Tours, France
| | - G Captier
- EA2415, Aide à la décision médicale personnalisée, Université Montpellier, Montpellier, France.,Laboratoire d'anatomie de Montpellier, UFR médecine, Université Montpellier, Montpellier, France
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26
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Landier M, Villemagne T, Le Touze A, Braïk K, Meignan P, Cook AR, Morel B, Lardy H, Binet A. The position of a written document in preoperative information for pediatric surgery: A randomized controlled trial on parental anxiety, knowledge, and satisfaction. J Pediatr Surg 2018; 53:375-380. [PMID: 28456425 DOI: 10.1016/j.jpedsurg.2017.04.009] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 03/21/2017] [Accepted: 04/17/2017] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Preoperative information is a legal and ethical obligation. Very little studies have evaluated the preoperative information method in pediatrics. Having a child operated on is stressful for the parents. Improving information is a way to lower their anxiety. Our study aims to measure the impact of a leaflet, which supports spoken information on parental anxiety, the comprehension-memorization of the information and their satisfaction. MATERIALS & METHODS Prospective study including 178 patients of outpatient surgery, randomized in two groups: spoken information versus spoken information supported by a leaflet, which is then handed out to the parents. The messages were identical: physiopathology, risks without treatment, surgical technique and its possible complications, description of the hospitalization day, and postoperative care. Parental evaluation was made with self-questionnaires after the preoperative consultation, then on the day of surgery. At each moment we evaluated the level of anxiety, satisfaction of information quality and the comprehension-memorization of the data. RESULTS Written information significantly improves the scores of comprehension-memorization, parental satisfaction and significantly decreases the level of anxiety. CONCLUSION Significant impact of the written document as communication support in pediatric surgery, validating the method and encouraging it to be generalized to other pediatric surgery acts. LEVEL OF EVIDENCE Level I. TYPE OF STUDY Prognosis study.
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Affiliation(s)
- M Landier
- Viscéral, Urological and Plastic Pediatric Surgery Department, Gatien de Clocheville Hospital, Tours 37000, France
| | - T Villemagne
- Viscéral, Urological and Plastic Pediatric Surgery Department, Gatien de Clocheville Hospital, Tours 37000, France
| | - A Le Touze
- Viscéral, Urological and Plastic Pediatric Surgery Department, Gatien de Clocheville Hospital, Tours 37000, France
| | - K Braïk
- Viscéral, Urological and Plastic Pediatric Surgery Department, Gatien de Clocheville Hospital, Tours 37000, France
| | - P Meignan
- Viscéral, Urological and Plastic Pediatric Surgery Department, Gatien de Clocheville Hospital, Tours 37000, France
| | - A R Cook
- Viscéral, Urological and Plastic Pediatric Surgery Department, Gatien de Clocheville Hospital, Tours 37000, France
| | - B Morel
- Pediatric Radiology Department, Gatien de Clocheville Hospital, Tours 37000, France
| | - H Lardy
- Viscéral, Urological and Plastic Pediatric Surgery Department, Gatien de Clocheville Hospital, Tours 37000, France
| | - A Binet
- Viscéral, Urological and Plastic Pediatric Surgery Department, Gatien de Clocheville Hospital, Tours 37000, France.
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27
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Chen HC, Cook AR, Asaoka S, Boschen JS, Windus TL, Miller JR. Escape of anions from geminate recombination in THF due to charge delocalization. Phys Chem Chem Phys 2018; 19:32272-32285. [PMID: 29192921 DOI: 10.1039/c7cp05880b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Geminate recombination of 24 radical anions (M˙-) with solvated protons (RH2+) was studied in tetrahydrofuran (THF) with pulse radiolysis. The recombination has two steps: (1) diffusion of M˙- and RH2+ together to form intimate (contact and solvent separated) ion pairs, driven by Coulomb attraction; (2) annihilation of anions due to proton transfer (PT) from RH2+ to M˙-. The non-exponential time-dependence of the geminate diffusion was determined. For all molecules protonated on O or N atoms the subsequent PT step is too fast (<0.2 ns) to measure, except for the anion of TCNE which did not undergo proton transfer. PT to C atoms was as slow as 70 ns and was always slow enough to be observable. A possible effect of charge delocalization on the PT rates could not be clearly separated from other factors. For 21 of the 24 molecules studied here, a free ion yield (71.6 ± 6.2 nmol J-1) comprising ∼29% of the total, was formed. This yield of "Type I" free ions is independent of the PT rate because it arises entirely by escape from the initial distribution of ion pair distances without forming intimate ion pairs. Three anions of oligo(9,9-dihexyl)fluorenes, Fn˙- (n = 2-4) were able to escape from intimate ion-pairs to form additional yields of "Type II" free ions with escape rate constants near 3 × 106 s-1. These experiments find no evidence for an inverted region for proton transfer.
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Affiliation(s)
- Hung-Cheng Chen
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973, USA.
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28
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Cook AR, Valášek M, Funston AM, Poliakov P, Michl J, Miller JR. p-Carborane Conjugation in Radical Anions of Cage–Cage and Cage–Phenyl Compounds. J Phys Chem A 2018; 122:798-810. [DOI: 10.1021/acs.jpca.7b10885] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andrew R. Cook
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Michal Valášek
- Institute
of Organic Chemistry and Biochemistry, ASCR, Prague 6 16610, Czech Republic
| | - Alison M. Funston
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
- School
of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Pavel Poliakov
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Josef Michl
- Institute
of Organic Chemistry and Biochemistry, ASCR, Prague 6 16610, Czech Republic
- Department
of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215, United States
| | - John R. Miller
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
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29
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Chen HC, Cook AR, Asaoka S, Boschen JS, Windus TL, Miller JR. Correction: Escape of anions from geminate recombination in THF due to charge delocalization. Phys Chem Chem Phys 2018; 20:3841-3842. [DOI: 10.1039/c8cp90016g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Correction for ‘Escape of anions from geminate recombination in THF due to charge delocalization’ by Hung-Cheng Chen et al., Phys. Chem. Chem. Phys., 2017, 19, 32272–32285.
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Affiliation(s)
- Hung-Cheng Chen
- Chemistry Department
- Brookhaven National Laboratory
- Upton
- New York 11973
- USA
| | - Andrew R. Cook
- Chemistry Department
- Brookhaven National Laboratory
- Upton
- New York 11973
- USA
| | - Sadayuki Asaoka
- Faculty of Materials Science and Engineering
- Kyoto Institute of Technology
- Kyoto 606-8585
- Japan
| | - Jeffery S. Boschen
- Department of Chemistry and Ames Laboratory (USDOE)
- Iowa State University
- Ames
- USA
| | - Theresa L. Windus
- Department of Chemistry and Ames Laboratory (USDOE)
- Iowa State University
- Ames
- USA
| | - John R. Miller
- Chemistry Department
- Brookhaven National Laboratory
- Upton
- New York 11973
- USA
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30
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Whitmore C, Cook AR, Mann T, Price ME, Emery E, Roughley N, Flint D, Stubbs S, Armstrong SJ, Rice H, Tattersall JEH. The efficacy of HI-6 DMS in a sustained infusion against percutaneous VX poisoning in the guinea-pig. Toxicol Lett 2017; 293:207-215. [PMID: 29129798 DOI: 10.1016/j.toxlet.2017.11.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 11/02/2017] [Accepted: 11/06/2017] [Indexed: 11/29/2022]
Abstract
Post-exposure nerve agent treatment usually includes administration of an oxime, which acts to restore function of the enzyme acetylcholinesterase (AChE). For immediate treatment of military personnel, this is usually administered with an autoinjector device, or devices containing the oxime such as pralidoxime, atropine and diazepam. In addition to the autoinjector, it is likely that personnel exposed to nerve agents, particularly by the percutaneous route, will require further treatment at medical facilities. As such, there is a need to understand the relationship between dose rate, plasma concentration, reactivation of AChE activity and efficacy, to provide supporting evidence for oxime infusions in nerve agent poisoning. Here, it has been demonstrated that intravenous infusion of HI-6, in combination with atropine, is efficacious against a percutaneous VX challenge in the conscious male Dunkin-Hartley guinea-pig. Inclusion of HI-6, in addition to atropine in the treatment, improved survival when compared to atropine alone. Additionally, erythrocyte AChE activity following poisoning was found to be dose dependent, with an increased dose rate of HI-6 (0.48mg/kg/min) resulting in increased AChE activity. As far as we are aware, this is the first study to correlate the pharmacokinetic profile of HI-6 with both its pharmacodynamic action of reactivating nerve agent inhibited AChE and with its efficacy against a persistent nerve agent exposure challenge in the same conscious animal.
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Affiliation(s)
- C Whitmore
- CBR (Chemical, Biological, Radiological), Dstl Porton Down, Salisbury, Wiltshire, SP4 0JQ, United Kingdom.
| | - A R Cook
- CBR (Chemical, Biological, Radiological), Dstl Porton Down, Salisbury, Wiltshire, SP4 0JQ, United Kingdom
| | - T Mann
- CBR (Chemical, Biological, Radiological), Dstl Porton Down, Salisbury, Wiltshire, SP4 0JQ, United Kingdom
| | - M E Price
- CBR (Chemical, Biological, Radiological), Dstl Porton Down, Salisbury, Wiltshire, SP4 0JQ, United Kingdom
| | - E Emery
- CBR (Chemical, Biological, Radiological), Dstl Porton Down, Salisbury, Wiltshire, SP4 0JQ, United Kingdom
| | - N Roughley
- CBR (Chemical, Biological, Radiological), Dstl Porton Down, Salisbury, Wiltshire, SP4 0JQ, United Kingdom
| | - D Flint
- CBR (Chemical, Biological, Radiological), Dstl Porton Down, Salisbury, Wiltshire, SP4 0JQ, United Kingdom
| | - S Stubbs
- CBR (Chemical, Biological, Radiological), Dstl Porton Down, Salisbury, Wiltshire, SP4 0JQ, United Kingdom
| | - S J Armstrong
- CBR (Chemical, Biological, Radiological), Dstl Porton Down, Salisbury, Wiltshire, SP4 0JQ, United Kingdom
| | - H Rice
- CBR (Chemical, Biological, Radiological), Dstl Porton Down, Salisbury, Wiltshire, SP4 0JQ, United Kingdom
| | - J E H Tattersall
- CBR (Chemical, Biological, Radiological), Dstl Porton Down, Salisbury, Wiltshire, SP4 0JQ, United Kingdom
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31
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Landier M, Villemagne T, Le Touze A, Braïk K, Meignan P, Cook AR, Morel B, Lardy H, Binet A. [Impact of a written document for preoperative information on the use of Internet by parents]. Arch Pediatr 2017; 24:969-976. [PMID: 28927771 DOI: 10.1016/j.arcped.2017.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 06/09/2017] [Accepted: 08/06/2017] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Preoperative information is a legal and ethical obligation. Very few studies have evaluated the preoperative information method in pediatrics. Having a child operated on is stressful for parents. The use of Internet to look for data on the pathology and its treatment is frequent, but often unprofitable and sometimes even harmful. This study aimed to measure the impact of a leaflet, which supports spoken information in preoperative consultation, on parents' use of the Internet before surgery. MATERIAL AND METHODS Prospective study including 178 patients of outpatient surgery, randomized into two groups: spoken information alone versus spoken information supported by a personalized leaflet, which is then handed out to the parents. The messages were identical: physiopathology, risks without treatment, surgical technique, possible complications, description of the hospitalization day, and postoperative care. Parental evaluation was carried out with self-administered questionnaires after the preoperative consultation, then on the day of surgery. At each moment the rate of Internet use, its reasons, and the benefits were evaluated. RESULTS The written document significantly reduced the use of the Internet by parents regardless of the child's age, their degree of anxiety, their level of understanding, and the time between consultation and the intervention. CONCLUSION This study confirms the significant impact of the leaflet as a communication tool in pediatric surgery and the substantial utility for parents. This encourages us to generalize this method to other pediatric surgery acts.
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Affiliation(s)
- M Landier
- Service de chirurgie pédiatrique viscérale, urologique et plastique, hôpital Gatien-de-Clocheville, CHU de Tours, 49, boulevard Beranger, 37044 Tours, France
| | - T Villemagne
- Service de chirurgie pédiatrique viscérale, urologique et plastique, hôpital Gatien-de-Clocheville, CHU de Tours, 49, boulevard Beranger, 37044 Tours, France
| | - A Le Touze
- Service de chirurgie pédiatrique viscérale, urologique et plastique, hôpital Gatien-de-Clocheville, CHU de Tours, 49, boulevard Beranger, 37044 Tours, France
| | - K Braïk
- Service de chirurgie pédiatrique viscérale, urologique et plastique, hôpital Gatien-de-Clocheville, CHU de Tours, 49, boulevard Beranger, 37044 Tours, France
| | - P Meignan
- Service de chirurgie pédiatrique viscérale, urologique et plastique, hôpital Gatien-de-Clocheville, CHU de Tours, 49, boulevard Beranger, 37044 Tours, France
| | - A R Cook
- Service de chirurgie pédiatrique viscérale, urologique et plastique, hôpital Gatien-de-Clocheville, CHU de Tours, 49, boulevard Beranger, 37044 Tours, France
| | - B Morel
- Service de radiologie pédiatrique, hôpital Gatien-de-Clocheville, 37000 Tours, France
| | - H Lardy
- Service de chirurgie pédiatrique viscérale, urologique et plastique, hôpital Gatien-de-Clocheville, CHU de Tours, 49, boulevard Beranger, 37044 Tours, France
| | - A Binet
- Service de chirurgie pédiatrique viscérale, urologique et plastique, hôpital Gatien-de-Clocheville, CHU de Tours, 49, boulevard Beranger, 37044 Tours, France.
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Kassite I, Braïk K, Morel B, Villemagne T, Szwarc C, Maakaroun Z, Cook AR, Lardy H, Binet A. High pressure balloon dilatation of the ureterovesical junction in primary obstructive megaureter: Infectious morbidity. Prog Urol 2017; 27:507-512. [PMID: 28867581 DOI: 10.1016/j.purol.2017.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 05/31/2017] [Accepted: 07/05/2017] [Indexed: 11/16/2022]
Abstract
INTRODUCTION The objective of this study is to investigate the infectious morbidity associated with high-pressure balloon dilatation (HPBD) and an indwelling double J stent, in primary obstructive megaureter. METHODS We reviewed the cases of 12 patients undergoing endoscopic treatment for primary obstructive megaureter from January 2012 to January 2015. The characteristics of the infection and data concerning the patient and the intervention were analyzed. RESULTS The frequency of preoperative urinary tract infection (UTI) was 58%. The procedure was feasible in 100% of cases. Two patients required a second dilatation. One patient underwent Cohen's ureteral reimplantation after failure of the second dilatation. The frequency of postoperative UTI was 25%. All these infections occurred in patients with a double J stent. None of the patients had UTI after stent removal. None of the patients developed postoperative vesicoureteral reflux (VUR) after HPBD. CONCLUSION Endoscopic balloon dilatation has been shown to have good short- mid- and long-term outcomes. In our experience, the morbidity of this procedure mostly results from infections, exclusively related to the use of a double J stent. The placement of a double J stent has a significant medical and economic impact. A definitive decision about the utility of double J stents will require studies of further dilatation without the placement of a double J stent. LEVEL OF EVIDENCE 4.
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Affiliation(s)
- I Kassite
- Service de chirurgie pédiatrique urologique, CHU de Tours, hôpital Gatien de Clocheville, 37000 Tours, France
| | - K Braïk
- Service de chirurgie pédiatrique urologique, CHU de Tours, hôpital Gatien de Clocheville, 37000 Tours, France
| | - B Morel
- Service de radiologie pédiatrique, CHU de Tours, hôpital Gatien de Clocheville, 37000 Tours, France
| | - T Villemagne
- Service de chirurgie pédiatrique urologique, CHU de Tours, hôpital Gatien de Clocheville, 37000 Tours, France
| | - C Szwarc
- Service de chirurgie pédiatrique urologique, CHU de Tours, hôpital Gatien de Clocheville, 37000 Tours, France
| | - Z Maakaroun
- Service de médecine infectieuse, CHU de Tours, hôpital Bretonneau, 37000 Tours, France
| | - A R Cook
- Service de chirurgie pédiatrique urologique, CHU de Tours, hôpital Gatien de Clocheville, 37000 Tours, France
| | - H Lardy
- Service de chirurgie pédiatrique urologique, CHU de Tours, hôpital Gatien de Clocheville, 37000 Tours, France
| | - A Binet
- Service de chirurgie pédiatrique urologique, CHU de Tours, hôpital Gatien de Clocheville, 37000 Tours, France.
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Smeyne RJ, Breckenridge CB, Beck M, Jiao Y, Butt MT, Wolf JC, Zadory D, Minnema DJ, Sturgess NC, Travis KZ, Cook AR, Smith LL, Botham PA. Assessment of the Effects of MPTP and Paraquat on Dopaminergic Neurons and Microglia in the Substantia Nigra Pars Compacta of C57BL/6 Mice. PLoS One 2016; 11:e0164094. [PMID: 27788145 PMCID: PMC5082881 DOI: 10.1371/journal.pone.0164094] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 09/20/2016] [Indexed: 12/21/2022] Open
Abstract
The neurotoxicity of paraquat dichloride (PQ) was assessed in two inbred strains of 9- or 16-week old male C57BL/6 mice housed in two different laboratories and compared to the effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). PQ was administered by intraperitoneal injections; either once (20 mg/kg) or twice (10 mg/kg) weekly for 3 weeks, while MPTP-HCl was injected 4 times on a single day (20 mg/kg/dose). Brains were collected 8, 16, 24, 48, 96 or 168 hours after the last PQ treatment, and 48 or 168 hours after MPTP treatment. Dopamine neurons in the substantia nigra pars compacta (SNpc) were identified by antibodies to tyrosine hydroxylase (TH+) and microglia were identified using Iba-1 immunoreactivity. The total number of TH+ neurons and the number of resting and activated microglia in the SNpc at 168 hours after the last dose were estimated using model- or design-based stereology, with investigators blinded to treatment. In a further analysis, a pathologist, also blinded to treatment, evaluated the SNpc and/or striatum for loss of TH+ neurons (SNpc) or terminals (striatum), cell death (as indicated by amino cupric silver uptake, TUNEL and/or caspase 3 staining) and neuroinflammation (as indicated by Iba-1 and/or GFAP staining). PQ, administered either once or twice weekly to 9- or 16-week old mice from two suppliers, had no effect on the number of TH+ neurons or microglia in the SNpc, as assessed by two groups, each blinded to treatment, using different stereological methods. PQ did not induce neuronal cell loss or degeneration in the SNpc or striatum. Additionally, there was no evidence of apoptosis, microgliosis or astrogliosis. In MPTP-treated mice, the number of TH+ neurons in the SNpc was significantly decreased and the number of activated microglia increased. Histopathological assessment found degenerating neurons/terminals in the SNpc and striatum but no evidence of apoptotic cell death. MPTP activated microglia in the SNpc and increased the number of astrocytes in the SNpc and striatum.
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Affiliation(s)
- Richard Jay Smeyne
- St. Jude Children’s Research Hospital, Dept. of Developmental Neurobiology, 262 Danny Thomas Place, Memphis, TN 38105, United States of America
- * E-mail:
| | - Charles B. Breckenridge
- Syngenta Crop Protection, LLC, P.O. Box 18300, Greensboro, NC 27419–8300, United States of America
| | - Melissa Beck
- WIL Research Laboratories, LLC., Ashland, OH 44805, United States of America
| | - Yun Jiao
- St. Jude Children’s Research Hospital, Dept. of Developmental Neurobiology, 262 Danny Thomas Place, Memphis, TN 38105, United States of America
| | - Mark T. Butt
- Tox Path Specialists, LLC, 8747 Chestnut Grove Road, Frederick, MD 21701–2607, United States of America
| | - Jeffrey C. Wolf
- Experimental Pathology Laboratories, Inc., 45600 Terminal Drive, Sterling, VA 20166, United States of America
| | - Dan Zadory
- Experimental Pathology Laboratories, Inc., 45600 Terminal Drive, Sterling, VA 20166, United States of America
| | - Daniel J. Minnema
- Syngenta Crop Protection, LLC, P.O. Box 18300, Greensboro, NC 27419–8300, United States of America
| | - Nicholas C. Sturgess
- Syngenta Limited, Jealott's Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, United Kingdom
| | - Kim Z. Travis
- Syngenta Limited, Jealott's Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, United Kingdom
| | - Andrew R. Cook
- Syngenta Limited, Jealott's Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, United Kingdom
| | - Lewis L. Smith
- University of Leicester, University Road, Leicester LE1 7RH, United Kingdom
| | - Philip A. Botham
- Syngenta Limited, Jealott's Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, United Kingdom
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Mezyk SP, Horne GP, Mincher BJ, Zalupski PR, Cook AR, Wishart JF. The Chemistry of Separations Ligand Degradation by Organic Radical Cations. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.proche.2016.10.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Tay MR, Low YL, Zhao X, Cook AR, Lee VJ. Comparison of Infrared Thermal Detection Systems for mass fever screening in a tropical healthcare setting. Public Health 2015; 129:1471-8. [PMID: 26296847 PMCID: PMC7111721 DOI: 10.1016/j.puhe.2015.07.023] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 06/09/2015] [Accepted: 07/12/2015] [Indexed: 12/01/2022]
Abstract
Objectives Fever screening systems, such as Infrared Thermal Detection Systems (ITDS), have been used for rapid identification of potential cases during respiratory disease outbreaks for public health management. ITDS detect a difference between the subject and ambient temperature, making deployment in hot climates more challenging. This study, conducted in Singapore, a tropical city, evaluates the accuracy of three different ITDS for fever detection compared with traditional oral thermometry and self-reporting in a clinical setting. Study design This study is a prospective operational evaluation conducted in the Singapore military on all personnel seeking medical care at a high-volume primary healthcare centre over a one week period in February 2014. Methods Three ITDS, the STE Infrared Fever Screening System (IFSS), the Omnisense Sentry MKIII and the handheld Quick Shot Infrared Thermoscope HT-F03B, were evaluated. Temperature measurements were taken outside the healthcare centre, under a sheltered walkway and compared to oral temperature. Subjects were asked if they had fever. Results There were 430 subjects screened, of whom 34 participants (7.9%) had confirmed fever, determined by oral thermometer measurement. The handheld infrared thermoscope had a very low sensitivity (29.4%), but a high specificity (96.8%). The STE ITDS had a moderate sensitivity (44.1%), but a very high specificity (99.1%). Self-reported fevers showed good sensitivity (88.2%) and specificity (93.9%). The sensitivity of the Omnisense ITDS (89.7%) was the highest among the three methods with good specificity (92.0%). Conclusion The new generation Omnisense ITDS displayed a relatively high sensitivity and specificity for fever. Though it has a lower sensitivity, the old generation STE ITDS system showed a very high specificity. Self-reporting of fever was reliable. The handheld thermograph should not be used as a fever-screening tool under tropical conditions. The new generation fever screening system displayed a relatively high sensitivity and specificity for fever. Self-reporting of fever was reliable compared to measured temperature. The handheld thermograph should not be used as a fever-screening tool under tropical conditions.
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Affiliation(s)
- M R Tay
- Biodefence Centre, Singapore Armed Forces, 778910, Singapore
| | - Y L Low
- Biodefence Centre, Singapore Armed Forces, 778910, Singapore
| | - X Zhao
- Saw Swee Hock School of Public Health, National University of Singapore, 117597, Singapore
| | - A R Cook
- Saw Swee Hock School of Public Health, National University of Singapore, 117597, Singapore; Yale-NUS College, National University of Singapore, 138614, Singapore; Program in Health Services and Systems Research, Duke-NUS Graduate Medical School, 169857, Singapore; Department of Statistics and Applied Probability, National University of Singapore, 138614, Singapore
| | - V J Lee
- Biodefence Centre, Singapore Armed Forces, 778910, Singapore; Saw Swee Hock School of Public Health, National University of Singapore, 117597, Singapore.
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Abstract
Influenza-like illness (ILI) case definitions, such as those from the European Centre for Disease Control and Prevention, World Health Organization (WHO) and United States Centers for Disease Control and Prevention, are commonly used for influenza surveillance. We assessed how various case definitions performed during the initial wave of influenza A(H1N1) pdm09 infections in Singapore on a cohort of 727 patients with two to three blood samples and whose symptoms were reviewed fortnightly from June to October 2009. Using seroconversion (≥ 4-fold rise) to A/California/7/2009 (H1N1), we identified 36 presumptive influenza A(H1N1)pdm09 episodes and 664 episodes unrelated to influenza A(H1N1)pdm09. Cough, fever and headache occurred more commonly in presumptive influenza A(H1N1)pdm09. Although the sensitivity was low (36%), the recently revised WHO ILI case definition gave a higher positive predictive value (42%) and positive likelihood ratio (13.3) than the other case definitions. Results including only episodes with primary care consultations were similar. Individuals who worked or had episodes with fever, cough or sore throat were more likely to consult a physician, while episodes with Saturday onset were less likely, with some consultations skipped or postponed. Our analysis supports the use of the revised WHO ILI case definition, which includes only cough in the presence of fever defined as body temperature ≥ 38 °C for influenza surveillance.
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Affiliation(s)
- L Jiang
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
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Zarzana CA, Groenewold GS, Mincher BJ, Mezyk SP, Wilden A, Schmidt H, Modolo G, Wishart JF, Cook AR. A Comparison of theγ-Radiolysis of TODGA and T(EH)DGA Using UHPLC-ESI-MS Analysis. Solvent Extraction and Ion Exchange 2015. [DOI: 10.1080/07366299.2015.1012885] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Zaikowski L, Mauro G, Bird M, Karten B, Asaoka S, Wu Q, Cook AR, Miller JR. Charge Transfer Fluorescence and 34 nm Exciton Diffusion Length in Polymers with Electron Acceptor End Traps. J Phys Chem B 2014; 119:7231-41. [DOI: 10.1021/jp510095p] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Lori Zaikowski
- Chemistry
and Physics Department, Dowling College, Oakdale, New York 11769, United States
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Gina Mauro
- Chemistry
and Physics Department, Dowling College, Oakdale, New York 11769, United States
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Matthew Bird
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Brianne Karten
- Chemistry
and Physics Department, Dowling College, Oakdale, New York 11769, United States
| | - Sadayuki Asaoka
- Department
of Biomolecular Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Qin Wu
- Center
for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Andrew R. Cook
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - John R. Miller
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
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Li X, Bird M, Mauro G, Asaoka S, Cook AR, Chen HC, Miller JR. Transport of Triplet Excitons along Continuous 100 nm Polyfluorene Chains. J Phys Chem B 2014; 119:7210-8. [DOI: 10.1021/jp509396s] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Xiang Li
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Matthew Bird
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Gina Mauro
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Sadayuki Asaoka
- Department
of Biomolecular Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Andrew R. Cook
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Hung-Cheng Chen
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
- Department
of Materials Science and Engineering, Stony Brook University, Stony Brook, New York 11790, United States
| | - John R. Miller
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
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Holroyd R, Miller JR, Cook AR, Nishikawa M. Pressure Tuning of Electron Attachment to Benzoquinones in Nonpolar Fluids: Continuous Adjustment of Free Energy Changes. J Phys Chem B 2014; 118:2164-71. [DOI: 10.1021/jp412090k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Richard Holroyd
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - John R. Miller
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Andrew R. Cook
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Masaru Nishikawa
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
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Minnema DJ, Travis KZ, Breckenridge CB, Sturgess NC, Butt M, Wolf JC, Zadory D, Beck MJ, Mathews JM, Tisdel MO, Cook AR, Botham PA, Smith LL. Dietary administration of paraquat for 13 weeks does not result in a loss of dopaminergic neurons in the substantia nigra of C57BL/6J mice. Regul Toxicol Pharmacol 2014; 68:250-8. [PMID: 24389362 DOI: 10.1016/j.yrtph.2013.12.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 12/23/2013] [Accepted: 12/25/2013] [Indexed: 10/25/2022]
Abstract
Several investigations have reported that mice administered paraquat dichloride (PQ·Cl2) by intraperitoneal injection exhibit a loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). In this study, male and female C57BL/6J mice were administered PQ·Cl2 in the diet at concentrations of 0 (control), 10, and 50ppm for a duration of 13weeks. A separate group of mice were administered 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) during week 12 as positive controls to produce a loss of dopaminergic neurons in the SNpc. The comparative effects of PQ and MPTP on the SNpc and/or striatum were assessed using neurochemical, neuropathological, and stereological endpoints. Morphological and stereological assessments were performed by investigators 'blinded' to the origin of the tissue. Neither dose of PQ·Cl2 (10 or 50 ppm in the diet) caused a loss of striatal dopamine or dopamine metabolite concentrations in the brains of mice. Pathological assessments of the SNpc and striatum showed no evidence of neuronal degeneration or astrocytic/microglial activation. Furthermore, the number of tyrosine hydroxylase-positive (TH(+)) neurons in the SNpc was not reduced in PQ-treated mice. In contrast, MPTP caused a decrease in striatal dopamine concentration, a reduction in TH(+) neurons in the SNpc, and significant pathological changes including astrocytic and microglial activation in the striatum and SNpc. The MPTP-induced effects were greater in males than in females. It is concluded that 13weeks of continuous dietary exposure of C57BL/6J mice to 50ppm PQ·Cl2 (equivalent to 10.2 and 15.6mg PQ ion/kg body weight/day for males and females, respectively) does not result in the loss of, or damage to, dopaminergic neurons in the SNpc.
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Affiliation(s)
- Daniel J Minnema
- Syngenta Crop Protection, LLC, P.O. Box 18300, Greensboro, NC 27419-8300, USA.
| | - Kim Z Travis
- Syngenta Limited, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
| | | | - Nicholas C Sturgess
- Syngenta Limited, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
| | - Mark Butt
- Tox Path Specialists, LLC, 8420 Gas House Pike, Frederick, MD 21701-2607, USA
| | - Jeffrey C Wolf
- Experimental Pathology Laboratories, Inc., 45600 Terminal Drive, Sterling, VA 20166, USA
| | - Dan Zadory
- Experimental Pathology Laboratories, Inc., 45600 Terminal Drive, Sterling, VA 20166, USA
| | | | - James M Mathews
- RTI International, 3040 Cornwallis Road, Research Triangle Park, NC 27709-2194, USA
| | - Merrill O Tisdel
- Syngenta Crop Protection, LLC, P.O. Box 18300, Greensboro, NC 27419-8300, USA
| | - Andrew R Cook
- Syngenta Limited, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
| | - Philip A Botham
- Syngenta Limited, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
| | - Lewis L Smith
- University of Leicester, University Road, Leicester, LE1 7RH, UK
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Shkrob IA, Marin TW, Hatcher JL, Cook AR, Szreder T, Wishart JF. Radiation Stability of Cations in Ionic Liquids. 2. Improved Radiation Resistance through Charge Delocalization in 1-Benzylpyridinium. J Phys Chem B 2013; 117:14385-99. [DOI: 10.1021/jp408242b] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ilya A. Shkrob
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Timothy W. Marin
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
- Chemistry
Department, Benedictine University, 5700 College Road, Lisle, Illinois 60532, United States
| | - Jasmine L. Hatcher
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - Andrew R. Cook
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - Tomasz Szreder
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
- Department
of Radiation Chemistry and Technology, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland
| | - James F. Wishart
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
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Fisher D, Tambyah PA, Lin RTP, Jureen R, Cook AR, Lim A, Ong B, Balm M, Ng TM, Hsu LY. Sustained meticillin-resistant Staphylococcus aureus control in a hyper-endemic tertiary acute care hospital with infrastructure challenges in Singapore. J Hosp Infect 2013; 85:141-8. [PMID: 24011440 PMCID: PMC7114850 DOI: 10.1016/j.jhin.2013.07.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 07/22/2013] [Indexed: 11/25/2022]
Abstract
Background Meticillin-resistant Staphylococcus aureus (MRSA) has been entrenched in Singapore hospitals since the 1980s, with an excess of 600 non-duplicate cases of infections (120 bacteraemia episodes) each year in our 995-bed university hospital. Approximately 5% of our hospital beds are used as isolation facilities. Aim To study the impact of an MRSA control bundle that was implemented via gradual geographic extension across hospital wards. Methods The bundle included active surveillance on admission and transfer/discharge to identify ward-based acquisition of MRSA, isolation and cohorting of MRSA-infected patients, enhanced hand hygiene initiatives, and publicly displayed feedback of MRSA acquisition and hand hygiene compliance rates. Implementation was between October 2006 and June 2010 in order to provide lead-time for the incremental development of infrastructural capacity, and to develop an ethic of infection prevention among staff. Results were analysed via interrupted time-series analysis. Findings MRSA infections fell midway through the implementation, with MRSA bacteraemia declining from 0.26 [95% confidence interval (CI): 0.18–0.34] cases per 1000 inpatient-days in the first quarter of 2004 to 0.11 (95% CI: 0.07–0.19) cases per 1000 inpatient-days in the first quarter of 2012. MRSA acquisition rates fell a year after the programme had been fully implemented, whereas hand hygiene compliance rose significantly from 47% (95% CI: 44–49) in the first quarter of 2009 to 69% (95% CI: 68–71) in the first quarter of 2012. Conclusion Successful staged implementation of an MRSA bundle in a hyper-endemic setting is sustainable and represents a model that may be adapted for similar settings.
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Affiliation(s)
- D Fisher
- Department of Medicine, National University Health System, Singapore; Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Infection Control Team, National University Health System, Singapore.
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Zamadar M, Cook AR, Lewandowska-Andralojc A, Holroyd R, Jiang Y, Bikalis J, Miller JR. Electron Transfer by Excited Benzoquinone Anions: Slow Rates for Two-Electron Transitions. J Phys Chem A 2013; 117:8360-7. [DOI: 10.1021/jp403113u] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Matibur Zamadar
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000,
United States
| | - Andrew R. Cook
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000,
United States
| | | | - Richard Holroyd
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000,
United States
| | - Yan Jiang
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000,
United States
| | - Jin Bikalis
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000,
United States
| | - John R. Miller
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000,
United States
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Affiliation(s)
- Andrew R. Cook
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11793-5000,
United States
| | - Matthew J. Bird
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11793-5000,
United States
| | - Sadayuki Asaoka
- Chemical
Resources Laboratory, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - John R. Miller
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11793-5000,
United States
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Breckenridge CB, Sturgess NC, Butt M, Wolf JC, Zadory D, Beck M, Mathews JM, Tisdel MO, Minnema D, Travis KZ, Cook AR, Botham PA, Smith LL. Pharmacokinetic, neurochemical, stereological and neuropathological studies on the potential effects of paraquat in the substantia nigra pars compacta and striatum of male C57BL/6J mice. Neurotoxicology 2013; 37:1-14. [PMID: 23523781 DOI: 10.1016/j.neuro.2013.03.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 03/12/2013] [Accepted: 03/12/2013] [Indexed: 11/19/2022]
Abstract
The pharmacokinetics and neurotoxicity of paraquat dichloride (PQ) were assessed following once weekly administration to C57BL/6J male mice by intraperitoneal injection for 1, 2 or 3 weeks at doses of 10, 15 or 25 mg/kg/week. Approximately 0.3% of the administered dose was taken up by the brain and was slowly eliminated, with a half-life of approximately 3 weeks. PQ did not alter the concentration of dopamine (DA), homovanillic acid (HVA) or 3,4-dihydroxyphenylacetic acid (DOPAC), or increase dopamine turnover in the striatum. There was inconsistent stereological evidence of a loss of DA neurons, as identified by chromogenic or fluorescent-tagged antibodies to tyrosine hydroxylase in the substantia nigra pars compacta (SNpc). There was no evidence that PQ induced neuronal degeneration in the SNpc or degenerating neuronal processes in the striatum, as indicated by the absence of uptake of silver stain or reduced immunolabeling of tyrosine-hydroxylase-positive (TH(+)) neurons. There was no evidence of apoptotic cell death, which was evaluated using TUNEL or caspase 3 assays. Microglia (IBA-1 immunoreactivity) and astrocytes (GFAP immunoreactivity) were not activated in PQ-treated mice 4, 8, 16, 24, 48, 96 or 168 h after 1, 2 or 3 doses of PQ. In contrast, mice dosed with the positive control substance, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 10mg/kg/dose×4 doses, 2 h apart), displayed significantly reduced DA and DOPAC concentrations and increased DA turnover in the striatum 7 days after dosing. The number of TH(+) neurons in the SNpc was reduced, and there were increased numbers of degenerating neurons and neuronal processes in the SNpc and striatum. MPTP-mediated cell death was not attributed to apoptosis. MPTP activated microglia and astrocytes within 4 h of the last dose, reaching a peak within 48 h. The microglial response ended by 96 h in the SNpc, but the astrocytic response continued through 168 h in the striatum. These results bring into question previous published stereological studies that report loss of TH(+) neurons in the SNpc of PQ-treated mice. This study also suggests that even if the reduction in TH(+) neurons reported by others occurs in PQ-treated mice, this apparent phenotypic change is unaccompanied by neuronal cell death or by modification of dopamine levels in the striatum.
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Zaikowski L, Kaur P, Gelfond C, Selvaggio E, Asaoka S, Wu Q, Chen HC, Takeda N, Cook AR, Yang A, Rosanelli J, Miller JR. Polarons, Bipolarons, and Side-By-Side Polarons in Reduction of Oligofluorenes. J Am Chem Soc 2012; 134:10852-63. [DOI: 10.1021/ja301494n] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Lori Zaikowski
- Chemistry and Physics
Department, Dowling College, Oakdale, NY
| | - Parmeet Kaur
- Chemistry and Physics
Department, Dowling College, Oakdale, NY
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Wishart JF, Funston AM, Szreder T, Cook AR, Gohdo M. Electron solvation dynamics and reactivity in ionic liquids observed by picosecond radiolysis techniques. Faraday Discuss 2012; 154:353-63; discussion 439-64, 465-71. [DOI: 10.1039/c1fd00065a] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Affiliation(s)
- Andrew R. Cook
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11793-5000
| | - Paiboon Sreearunothai
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11793-5000
- Sirindhorn International Institute of Technology, Thammasat University, Pathum Thai 12121, Thailand
| | - Sadayuki Asaoka
- Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - John R. Miller
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11793-5000
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Keller JM, Glusac KD, Danilov EO, McIlroy S, Sreearuothai P, Cook AR, Jiang H, Miller JR, Schanze KS. Negative polaron and triplet exciton diffusion in organometallic "molecular wires". J Am Chem Soc 2011; 133:11289-98. [PMID: 21644580 DOI: 10.1021/ja202898p] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The dynamics of negative polaron and triplet exciton transport within a series of monodisperse platinum (Pt) acetylide oligomers is reported. The oligomers consist of Pt-acetylide repeats, [PtL(2)-C≡C-Ph-C≡C-](n) (where L = PBu(3) and Ph = 1,4-phenylene, n = 2, 3, 6, and 10), capped with naphthalene diimide (NDI) end groups. The Pt-acetylide segments are electro- and photoactive, and they serve as conduits for transport of electrons (negative polaron) and triplet excitons. The NDI end groups are relatively strong acceptors, serving as traps for the carriers. Negative polaron transport is studied by using pulse radiolysis/transient absorption at the Brookhaven National Laboratory Laser-Electron Accelerator Facility (LEAF). Electrons are rapidly attached to the oligomers, with some fraction initially residing upon the Pt-acetylide chains. The dynamics of transport are resolved by monitoring the spectral changes associated with transfer of electrons from the chain to the NDI end group. Triplet exciton transport is studied by femtosecond-picosecond transient absorption spectroscopy. Near-UV excitation leads to rapid production of triplet excitons localized on the Pt-acetylide chains. The excitons transport to the chain ends, where they are annihilated by charge separation with the NDI end group. The dynamics of triplet transport are resolved by transient absorption spectroscopy, taking advantage of the changes in spectra associated with decay of the triplet exciton and rise of the charge-separated state. The results indicate that negative polarons and excitons are transported rapidly, on average moving distances of ~3 nm in less than 200 ps. Analysis of the dynamics suggests diffusive transport by a site-to-site hopping mechanism with hopping times of ~27 ps for triplets and <10 ps for electrons.
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Affiliation(s)
- Julia M Keller
- Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, USA
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