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Barnett A, Karnes JJ, Lu J, Major DR, Oakdale JS, Grew KN, McClure JP, Molinero V. Exponential Water Uptake in Ionomer Membranes Results from Polymer Plasticization. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c01042] [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: 11/28/2022]
Affiliation(s)
- Adam Barnett
- Department of Chemistry, The University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850, United States
| | - John J. Karnes
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Jibao Lu
- Department of Chemistry, The University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850, United States
| | - Dale R. Major
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - James S. Oakdale
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States
| | - Kyle N. Grew
- DEVCOM Army Research Laboratory, Adelphi, Maryland 20783, United States
| | - Joshua P. McClure
- DEVCOM Army Research Laboratory, Adelphi, Maryland 20783, United States
| | - Valeria Molinero
- Department of Chemistry, The University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850, United States
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2
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Burpo FJ, Losch AR, Nagelli EA, Winter SJ, Bartolucci SF, McClure JP, Baker DR, Bui JK, Burns AR, O'Brien SF, Forcherio GT, Aikin BR, Healy KM, Remondelli MH, Mitropoulos AN, Richardson L, Wickiser JK, Chu DD. A Salt-Templated Synthesis Method for Porous Platinum-based Macrobeams and Macrotubes. J Vis Exp 2020. [PMID: 32478752 DOI: 10.3791/61395] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The synthesis of high surface area porous noble metal nanomaterials generally relies on time consuming coalescence of pre-formed nanoparticles, followed by rinsing and supercritical drying steps, often resulting in mechanically fragile materials. Here, a method to synthesize nanostructured porous platinum-based macrotubes and macrobeams with a square cross section from insoluble salt needle templates is presented. The combination of oppositely charged platinum, palladium, and copper square planar ions results in the rapid formation of insoluble salt needles. Depending on the stoichiometric ratio of metal ions present in the salt-template and the choice of chemical reducing agent, either macrotubes or macrobeams form with a porous nanostructure comprised of either fused nanoparticles or nanofibrils. Elemental composition of the macrotubes and macrobeams, determined with x-ray diffractometry and x-ray photoelectron spectroscopy, is controlled by the stoichiometric ratio of metal ions present in the salt-template. Macrotubes and macrobeams may be pressed into free standing films, and the electrochemically active surface area is determined with electrochemical impedance spectroscopy and cyclic voltammetry. This synthesis method demonstrates a simple, relatively fast approach to achieve high-surface area platinum-based macrotubes and macrobeams with tunable nanostructure and elemental composition that may be pressed into free-standing films with no required binding materials.
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Affiliation(s)
- F John Burpo
- Department of Chemistry and Life Science, United States Military Academy; Photonics Research Center, United States Military Academy;
| | - Anchor R Losch
- Department of Chemistry and Life Science, United States Military Academy
| | - Enoch A Nagelli
- Department of Chemistry and Life Science, United States Military Academy; Photonics Research Center, United States Military Academy
| | - Stephen J Winter
- Department of Chemistry and Life Science, United States Military Academy
| | | | - Joshua P McClure
- United States Army Research Laboratory-Sensors and Electron Devices Directorate
| | - David R Baker
- United States Army Research Laboratory-Sensors and Electron Devices Directorate
| | - Jack K Bui
- Department of Chemistry and Life Science, United States Military Academy
| | - Alvin R Burns
- Department of Chemistry and Life Science, United States Military Academy
| | - Sean F O'Brien
- Department of Chemistry and Life Science, United States Military Academy
| | - Greg T Forcherio
- United States Army Research Laboratory-Sensors and Electron Devices Directorate
| | - Brittany R Aikin
- Department of Chemistry and Life Science, United States Military Academy
| | - Kelsey M Healy
- Department of Chemistry and Life Science, United States Military Academy
| | - Mason H Remondelli
- Department of Chemistry and Life Science, United States Military Academy
| | - Alexander N Mitropoulos
- Department of Chemistry and Life Science, United States Military Academy; Department of Mathematical Sciences, United States Military Academy
| | - Lance Richardson
- Department of Chemistry and Life Science, United States Military Academy; Photonics Research Center, United States Military Academy
| | - J Kenneth Wickiser
- Department of Chemistry and Life Science, United States Military Academy
| | - Deryn D Chu
- United States Army Research Laboratory-Sensors and Electron Devices Directorate
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Palm KJ, Murray JB, McClure JP, Leite MS, Munday JN. In Situ Optical and Stress Characterization of Alloyed Pd xAu 1-x Hydrides. ACS Appl Mater Interfaces 2019; 11:45057-45067. [PMID: 31670929 DOI: 10.1021/acsami.9b14244] [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] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
PdxAu1-x alloys have recently shown great promise for next-generation optical hydrogen sensors due to their increased chemical durability while their optical sensitivity to small amounts of hydrogen gas is maintained. However, the correlation between chemical composition and the dynamic optical behavior upon hydrogenation/dehydrogenation is currently not well understood. A complete understanding of this relation is necessary to optimize future sensors and nanophotonic devices. Here, we quantify the dynamic optical, chemical, and mechanical properties of thin film PdxAu1-x alloys as they are exposed to H2 by combining in situ ellipsometry with gravimetric and stress measurements. We demonstrate the dynamic optical property dependence of the film upon hydrogenation and directly correlate it with the hydrogen content up to a maximum of 7 bar of H2. With this measurement, we find that the thin films exhibit their strongest optical sensitivity to H2 in the near-infrared. We also discover higher hydrogen-loading amounts as compared to previous measurements for alloys with low atomic percent Pd. Specifically, a measurable optical and gravimetric hydrogen response in alloys as low as 34% Pd is found, when previous works have suggested a disappearance of this response near 55% Pd. This result suggests that differences in film stress and microstructuring play a crucial role in the sorption behavior. We directly measure the thin film stress and morphology upon hydrogenation and show that the alloys have a substantially higher relative stress change than pure Pd, with the pure Pd data point falling 0.9 GPa below the expected trend line. Finally, we use the measured optical properties to illustrate the applicability of these alloys as grating structures and as a planar physical encryption scheme, where we show significant and variable changes in reflectivity upon hydrogenation. These results lay the foundation for the composition and design of next-generation hydrogen sensors and tunable photonic devices.
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Affiliation(s)
| | | | - Joshua P McClure
- Sensors and Electron Devices Directorate , U.S. Army Research Laboratory , 2800 Powder Mill Road , Adelphi , Maryland 20783-1197 , United States
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4
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Forcherio GT, Baker DR, Leff AC, Boltersdorf J, McClure JP, Grew KN, Lundgren CA. Photodeposition of Pd onto Colloidal Au Nanorods by Surface Plasmon Excitation. J Vis Exp 2019. [PMID: 31475988 DOI: 10.3791/60041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
A protocol is described to photocatalytically guide Pd deposition onto Au nanorods (AuNR) using surface plasmon resonance (SPR). Excited plasmonic hot electrons upon SPR irradiation drive reductive deposition of Pd on colloidal AuNR in the presence of [PdCl4]2-. Plasmon-driven reduction of secondary metals potentiates covalent, sub-wavelength deposition at targeted locations coinciding with electric field "hot-spots" of the plasmonic substrate using an external field (e.g., laser). The process described herein details a solution-phase deposition of a catalytically-active noble metal (Pd) from a transition metal halide salt (H2PdCl4) onto aqueously-suspended, anisotropic plasmonic structures (AuNR). The solution-phase process is amenable to making other bimetallic architectures. Transmission UV-vis monitoring of the photochemical reaction, coupled with ex situ XPS and statistical TEM analysis, provide immediate experimental feedback to evaluate properties of the bimetallic structures as they evolve during the photocatalytic reaction. Resonant plasmon irradiation of AuNR in the presence of [PdCl4]2- creates a thin, covalently-bound Pd0 shell without any significant dampening effect on its plasmonic behavior in this representative experiment/batch. Overall, plasmonic photodeposition offers an alternative route for high-volume, economical synthesis of optoelectronic materials with sub-5 nm features (e.g., heterometallic photocatalysts or optoelectronic interconnects).
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Affiliation(s)
| | - David R Baker
- Sensors & Electron Devices Directorate, U.S. Army Research Laboratory
| | - Asher C Leff
- Sensors & Electron Devices Directorate, U.S. Army Research Laboratory; General Technical Services
| | | | - Joshua P McClure
- Sensors & Electron Devices Directorate, U.S. Army Research Laboratory
| | - Kyle N Grew
- Sensors & Electron Devices Directorate, U.S. Army Research Laboratory
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McClure JP, Boltersdorf J, Baker DR, Farinha TG, Dzuricky N, Villegas CEP, Rocha AR, Leite MS. Structure-Property-Performance Relationship of Ultrathin Pd-Au Alloy Catalyst Layers for Low-Temperature Ethanol Oxidation in Alkaline Media. ACS Appl Mater Interfaces 2019; 11:24919-24932. [PMID: 31044596 DOI: 10.1021/acsami.9b01389] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Pd-containing alloys are promising materials for catalysis. Yet, the relationship of the structure-property performance strongly depends on their chemical composition, which is currently not fully resolved. Herein, we present a physical vapor deposition methodology for developing PdxAu1-x alloys with fine control over the chemical composition. We establish direct correlations between the composition and these materials' structural and electronic properties with its catalytic activity in an ethanol (EtOH) oxidation reaction. By combining X-ray diffraction (XRD) and X-ray photelectron spectroscopy (XPS) measurements, we validate that the Pd content within both bulk and surface compositions can be finely controlled in an ultrathin-film regime. Catalytic oxidation of EtOH on the PdxAu1-x electrodes presents the largest forward-sweeping current density for x = 0.73 at ∼135 mA cm-2, with the lowest onset potential and largest peak activity of 639 A gPd-1 observed for x = 0.58. Density functional theory (DFT) calculations and XPS measurements demonstrate that the valence band of the alloys is completely dominated by Pd particularly near the Fermi level, regardless of its chemical composition. Moreover, DFT provides key insights into the PdxAu1-x ligand effect, with relevant chemisorption activity descriptors probed for a large number of surface arrangements. These results demonstrate that alloys can outperform pure metals in catalytic processes, with fine control of the chemical composition being a powerful tuning knob for the electronic properties and, therefore, the catalytic activity of ultrathin PdxAu1-x catalysts. Our high-throughput experimental methodology, in connection with DFT calculations, provides a unique foundation for further materials' discovery, including machine-learning predictions for novel alloys, the development of Pd-alloyed membranes for the purification of reformate gases, binder-free ultrathin electrocatalysts for fuel cells, and room temperature lithography-based development of nanostructures for optically driven processes.
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Affiliation(s)
- Joshua P McClure
- Sensors and Electron Devices Directorate , U.S. Army Research Laboratory , Adelphi , Maryland 20783 , United States
| | - Jonathan Boltersdorf
- Sensors and Electron Devices Directorate , U.S. Army Research Laboratory , Adelphi , Maryland 20783 , United States
| | - David R Baker
- Sensors and Electron Devices Directorate , U.S. Army Research Laboratory , Adelphi , Maryland 20783 , United States
| | | | | | - Cesar E P Villegas
- Instituto de Física Teórica , Universidade Estadual Paulista , São Paulo , 01140-070 , Brazil
- Departamento de Ciencias , Universidad Privada del Norte , Avenida Andrés Belaunde cdra 10 s/n , Comas , Peru
| | - Alexandre R Rocha
- Instituto de Física Teórica , Universidade Estadual Paulista , São Paulo , 01140-070 , Brazil
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6
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Burpo FJ, Nagelli EA, Morris LA, McClure JP, Ryu MY, Palmer JL. A Rapid Synthesis Method for Au, Pd, and Pt Aerogels Via Direct Solution-Based Reduction. J Vis Exp 2018. [PMID: 29985323 DOI: 10.3791/57875] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Here, a method to synthesize gold, palladium, and platinum aerogels via a rapid, direct solution-based reduction is presented. The combination of various precursor noble metal ions with reducing agents in a 1:1 (v/v) ratio results in the formation of metal gels within seconds to minutes compared to much longer synthesis times for other techniques such as sol-gel. Conducting the reduction step in a microcentrifuge tube or small volume conical tube facilitates a proposed nucleation, growth, densification, fusion, equilibration model for gel formation, with final gel geometry smaller than the initial reaction volume. This method takes advantage of the vigorous hydrogen gas evolution as a by-product of the reduction step, and as a consequence of reagent concentrations. The solvent accessible specific surface area is determined with both electrochemical impedance spectroscopy and cyclic voltammetry. After rinsing and freeze drying, the resulting aerogel structure is examined with scanning electron microscopy, X-ray diffractometry, and nitrogen gas adsorption. The synthesis method and characterization techniques result in a close correspondence of aerogel ligament sizes. This synthesis method for noble metal aerogels demonstrates that high specific surface area monoliths may be achieved with a rapid and direct reduction approach.
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Affiliation(s)
- Fred J Burpo
- Department of Chemistry and Life Science, United States Military Academy, West Point;
| | - Enoch A Nagelli
- Department of Chemistry and Life Science, United States Military Academy, West Point
| | - Lauren A Morris
- Armament Research, Development and Engineering Center, U.S. Army RDECOM-ARDEC
| | - Joshua P McClure
- Sensors and Electron Devices Directorate, United States Army Research Laboratory
| | - Madeline Y Ryu
- Department of Chemistry and Life Science, United States Military Academy, West Point
| | - Jesse L Palmer
- Department of Chemistry and Life Science, United States Military Academy, West Point
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7
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Burpo FJ, Nagelli EA, Winter SJ, McClure JP, Bartolucci SF, Burns AR, O'Brien SF, Chu DD. Salt-Templated Hierarchically Porous Platinum Macrotube Synthesis. ChemistrySelect 2018. [DOI: 10.1002/slct.201800416] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Fred. J. Burpo
- Department of Chemistry and Life Science; United States Military Academy, West Point; New York 10996 USA
| | - Enoch A. Nagelli
- Department of Chemistry and Life Science; United States Military Academy, West Point; New York 10996 USA
| | - Stephen J. Winter
- Department of Chemistry and Life Science; United States Military Academy, West Point; New York 10996 USA
| | - Joshua P. McClure
- United States Army Research Laboratory-Sensors and Electron Devices Directorate, Adelphi; Maryland 20783 USA
| | - Stephen F. Bartolucci
- Benet Laboratories; Armament Research; Development and Engineering Center, U.S. Army RDECOM-ARDEC, Watervliet; New York 12189 USA
| | - Alvin R. Burns
- Department of Chemistry and Life Science; United States Military Academy, West Point; New York 10996 USA
| | - Sean F. O'Brien
- Department of Chemistry and Life Science; United States Military Academy, West Point; New York 10996 USA
| | - Deryn D. Chu
- United States Army Research Laboratory-Sensors and Electron Devices Directorate, Adelphi; Maryland 20783 USA
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8
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McClure JP, Grew KN, Baker DR, Gobrogge E, Das N, Chu D. Harvesting resonantly-trapped light for small molecule oxidation reactions at the Au/α-Fe 2O 3 interface. Nanoscale 2018; 10:7833-7850. [PMID: 29664495 DOI: 10.1039/c8nr01330f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Plasmonic metal nanoparticles (NPs) extend the overall light absorption of semiconductor materials. However, it is not well understood how coupling metal NPs to semiconductors alters the photo-electrochemical activity of small molecule oxidation (SMO) reactions. Different photo-anode electrodes comprised of Au NPs and α-Fe2O3 are designed to elucidate how the coupling plays not only a role in the water oxidation reaction (WO) but also performs for different SMO reactions. In this regard, Au NPs are inserted at specific regions within and/or on α-Fe2O3 layers created with a sequential electron beam evaporation method and multiple annealing treatments. The SMO and WO reactions are probed with broad-spectrum irradiation experiments with an emphasis on light-driven enhancements above and below the α-Fe2O3 band gap. Thin films of α-Fe2O3 supported on a gold back reflective layer resonantly-traps incident light leading to enhanced SMO/WO conversion efficiencies at high overpotential (η) for above band-gap excitations with no SMO activity observed at low η. In contrast, a substantial increase in the light-driven SMO activity is observed at low η, as well as for below band-gap excitations when sufficiently thin α-Fe2O3 films are decorated with Au NPs at the solution-electrode interface. The enhanced photo-catalytic activity is correlated with increased surface oxygen content (hydroxyl groups) at the Au/α-Fe2O3 interface, as well as simulated volume-integrated near-field enhancements over select regions of the Au/α-Fe2O3 interface providing an important platform for future SMO/WO photo-electrocatalyst development.
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Affiliation(s)
- Joshua P McClure
- U.S. Army Research Laboratory, Adelphi, MD, 2800 Powder Mill Road, Adelphi, MD 20783, USA.
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Jiang R, Tran DT, McClure JP. Non-precious Mn1.5Co1.5O4–FeNx/C nanocomposite as a synergistic catalyst for oxygen reduction in alkaline media. RSC Adv 2016. [DOI: 10.1039/c6ra15040c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [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] Open
Abstract
A nanocomposite material containing non-precious bimetal oxides and FeN-doped carbon was synthesized with double synergistic effect for ORR.
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Affiliation(s)
- Rongzhong Jiang
- Sensors and Electron Devices Directorate
- U.S. Army Research Laboratory
- Adelphi
- USA
| | - Dat T. Tran
- Sensors and Electron Devices Directorate
- U.S. Army Research Laboratory
- Adelphi
- USA
| | - Joshua P. McClure
- Sensors and Electron Devices Directorate
- U.S. Army Research Laboratory
- Adelphi
- USA
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Jiang R, Tran DT, McClure JP, Chu D. Nano-Structured Bio-Inorganic Hybrid Material for High Performing Oxygen Reduction Catalyst. ACS Appl Mater Interfaces 2015; 7:18530-18539. [PMID: 26280984 DOI: 10.1021/acsami.5b04714] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this study, we demonstrate a non-Pt nanostructured bioinorganic hybrid (BIH) catalyst for catalytic oxygen reduction in alkaline media. This catalyst was synthesized through biomaterial hemin, nanostructured Ag-Co alloy, and graphene nano platelets (GNP) by heat-treatment and ultrasonically processing. This hybrid catalyst has the advantages of the combined features of these bio and inorganic materials. A 10-fold improvement in catalytic activity (at 0.8 V vs RHE) is achieved in comparison of pure Ag nanoparticles (20-40 nm). The hybrid catalyst reaches 80% activity (at 0.8 V vs RHE) of the state-of-the-art catalyst (containing 40% Pt and 60% active carbon). Comparable catalytic stability for the hybrid catalyst with the Pt catalyst is observed by chronoamperometric experiment. The hybrid catalyst catalyzes 4-electron oxygen reduction to produce water with fast kinetic rate. The rate constant obtained from the hybrid catalyst (at 0.6 V vs RHE) is 4 times higher than that of pure Ag/GNP catalyst. A catalytic model is proposed to explain the oxygen reduction reaction at the BIH catalyst.
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Affiliation(s)
- Rongzhong Jiang
- Sensors and Electron Devices Directorate, U.S. Army Research Laboratory , 2800 Powder Mill Road, Adelphi, Maryland 20783-1197, United States
| | - Dat T Tran
- Sensors and Electron Devices Directorate, U.S. Army Research Laboratory , 2800 Powder Mill Road, Adelphi, Maryland 20783-1197, United States
| | - Joshua P McClure
- Sensors and Electron Devices Directorate, U.S. Army Research Laboratory , 2800 Powder Mill Road, Adelphi, Maryland 20783-1197, United States
| | - Deryn Chu
- Sensors and Electron Devices Directorate, U.S. Army Research Laboratory , 2800 Powder Mill Road, Adelphi, Maryland 20783-1197, United States
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Affiliation(s)
- Rongzhong Jiang
- Sensors and Electron Devices Directorate,
U.S. Army Research Laboratory, 2800
Powder Mill Road, Adelphi, Maryland 20783-1197, United States
| | - Dat T. Tran
- Sensors and Electron Devices Directorate,
U.S. Army Research Laboratory, 2800
Powder Mill Road, Adelphi, Maryland 20783-1197, United States
| | - Joshua P. McClure
- Sensors and Electron Devices Directorate,
U.S. Army Research Laboratory, 2800
Powder Mill Road, Adelphi, Maryland 20783-1197, United States
| | - Deryn Chu
- Sensors and Electron Devices Directorate,
U.S. Army Research Laboratory, 2800
Powder Mill Road, Adelphi, Maryland 20783-1197, United States
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12
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Jiang R, Moton E, McClure JP, Bowers Z. A Highly Active and Alcohol-Tolerant Cathode Electrocatalyst Containing Ag Nanoparticles Supported on Graphene. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2014.01.134] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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13
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Crow A, Davidson M, McClure JP. Time is of the essence. Arch Dis Child Fetal Neonatal Ed 2004; 89:F563-4. [PMID: 15499157 PMCID: PMC1721800 DOI: 10.1136/adc.2003.048512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Abstract
Naevoid hypertrichosis is an unusual congenital disorder consisting of a solitary circumscribed area of terminal hair growth which is not associated with any other systemic abnormalities. We describe a patient with multiple areas of circumscribed naevoid hypertrichosis on the trunk and limbs who also had lipodystrophy at some affected sites.
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Abstract
We report two new cases of Rothmund-Thomson syndrome which emphasize the less well-known non-dermatological complications, namely: hypodontia, soft tissue contractures, proportionate short stature, hypogonadism, anaemia and osteogenic sarcoma. Genetic analysis of these and previously reported pedigrees supports autosomal recessive inheritance.
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Abstract
We report a Scottish child with inv dup (15) and compare the clinical features with those of previously reported cases. Since the first report by Parker and Alfi in 1972, there have been 44 reports of patients with confirmed or suspected inv dup (15). The extra chromosomal material has been variously described, but in all cases there appears to be an additional G group sized chromosome in which both ends are derived from the short arm, centromere, and proximal long arm of chromosome 15. In most cases there are satellites at both ends of this extra chromosome. We report the first patient from Scotland with similar cytogenetic findings.
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Ratcliffe WA, McClure JP, Auld WH, Honour JW, Fraser R, Ratcliffe JG. Precocious pseudopuberty due to a rare form of congenital adrenal hyperplasia. Biochemical investigation and pitfalls in interpretation of hormone assays. Ann Clin Biochem 1982; 19:145-50. [PMID: 7092138 DOI: 10.1177/000456328201900303] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The biochemical investigation is described of a boy who presented with precocious puberty at the age of 3 years 9 months due to a rare form of congenital adrenal hyperplasia (CAH), steroid 11 beta-hydroxylase deficiency. Serum androgen levels were grossly elevated (17 hydroxyandrogens 10 nmol/l, androstenedione 129 nmol/l), 17 hydroxyprogesterone was modestly elevated (21 nmol/l), while serum gonadotrophins were low and testes were prepubertal in size. The major differential diagnosis was between an androgen-producing tumour and CAH. Initial serum and urine corticosteroid concentrations and their responses to dexamethasone were diagnostically misleading, later found to be due to lack of specificity of the radioimmunoassays and fluorimetric methods employed. Elevated basal plasma ACTH levels and suppression of androgen and ACTH levels by dexamethasone strongly suggested CAH. Definitive diagnosis of an 11 beta-hydroxylase defect was established by capillary column gas liquid chromatography of urine which demonstrated excess androgen and 11-deoxycortisol metabolites but no cortisol metabolites. The diagnosis was confirmed by specific serum assays of 11-deoxycortisol, deoxycorticosterone, and cortisol. The contribution of hormone assays and a protocol for their use in the diagnosis and monitoring of precocious puberty is discussed.
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Abstract
Since Menetrier's original description in 1888 many cases of hypertrophic gastritis have been recorded in adults. Only recently has a similar syndrome been described in childhood. The case reported demonstrates the characteristic features of the condition (the duration was rather longer than in other reported cases) and diagnosis, clinical course and aetiology are discussed. In contrast to the adult disease this illness is usually short-lived with full clinical and histological remission occurring within a few months.
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Ferguson A, McClure JP, Townley RR. Intraepithelial lymphocyte counts in small intestinal biopsies from children with diarrhoea. Acta Paediatr Scand 1976; 65:541-6. [PMID: 961407 DOI: 10.1111/j.1651-2227.1976.tb04929.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
We have investigated small intestinal biopsies from children with coeliac disease, acute gastroenteritis, failure to thrive and giardiasis, to find out if a high intraepithelial lymphocyte count is a feature specific to coeliac disease, or whether it is always associated with partial or subtotal villous atrophy. The results indicate that the normal range for childrens' intraepithelial lymphocyte counts is similar to that for adults (around 6-40 lymphocytes per 100 epithelial cells); that counts are high in coeliac disease, but also in some children with giardiasis or with failure to thrive in whom the jejunal biopsy appears otherwise normal; and that intraepithelial lymphocyte counts are normal in acute gastroenteritis even when there is partial villous atrophy with increased lamina propria lymphoid cell infiltrate. Thus, this measurement of small intestinal lymphocyte infiltration may be of diagnostic value is differentiating the diarrhoea of food intolerance from infectious diarrhoeas in young children.
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Abstract
In an attempt to demonstrate local cell-mediated immunity (C.M.I.) to gliadin in patients with coeliac disease, fragments of jejunal-biopsy specimens were cultured in the presence and absence of alpha-gliadin and the culture-medium was assayed for its capacity to inhibit migration of normal human peripheral-blood leucocytes (i.e., for a migration-inhibition factor [M.I.F.]). No M.I.F. activity was detected in the culture-medium when biopsy specimens from patients with coeliac disease or controls were cultured without added antigen. However, an M.I.F. was secreted into the culture-medium when biopsy specimens from patients with coeliac disease were cultured with alpha-gliadin. These findings suggest that there is a population of lymphocytes which are sensitised to gliadin in the intestinal mucosa of patients with untreated coeliac disease. They support the theory that a local C.M.I. reaction to gliadin may be the cause of villous atrophy and crypt hyperplasia in coeliac disease.
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