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“Laser microprobe mass spectrometry of quaternary phosphonium salts: direct versus matrix-assisted laser desorption”. Claereboudt J, Claeys M, Geise H, Gijbels R, Vertes A, Journal of the American Society for Mass Spectrometry 4, 798 (1993). http://doi.org/10.1016/1044-0305(93)80038-Z
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.945
Times cited: 17
DOI: 10.1016/1044-0305(93)80038-Z
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“Quantitative secondary ion mass spectrometry depth profiling of surface layers of cubic silver halide microcrystals”. Verlinden G, Gijbels R, Geuens I, Journal of the American Society for Mass Spectrometry 10, 1016 (1999). http://doi.org/10.1016/S1044-0305(99)00064-1
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.786
Times cited: 4
DOI: 10.1016/S1044-0305(99)00064-1
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“Modeling of glow discharge sources with flat and pin cathodes and implications for mass spectrometric analysis”. Bogaerts A, Gijbels R, Journal of the American Society of Mass Spectrometry 8, 1021 (1997). http://doi.org/10.1016/S1044-0305(97)00120-7
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.786
Times cited: 15
DOI: 10.1016/S1044-0305(97)00120-7
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“Nanodiamonds do not provide unique evidence for a Younger Dryas impact”. Tian H, Schryvers D, Claeys P, Proceedings of the National Academy of Sciences of the United States of America 108, 40 (2011). http://doi.org/10.1073/pnas.1007695108
Abstract: Microstructural, δ13C isotope and C/N ratio investigations were conducted on excavated material from the black Younger Dryas boundary in Lommel, Belgium, aiming for a characterisation of the carbon content and structures. Cubic diamond nanoparticles are found in large numbers. The larger ones with diameters around or above 10 nm often exhibit single or multiple twins. The smaller ones around 5 nm in diameter are mostly defect-free. Also larger flake-like particles, around 100 nm in lateral dimension, with a cubic diamond structure are observed as well as large carbon onion structures. The combination of these characteristics does not yield unique evidence for an exogenic impact related to the investigated layer.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.661
Times cited: 32
DOI: 10.1073/pnas.1007695108
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“Detection of amyloid fibrils in Parkinson’s disease using plasmonic chirality”. Kumar J, Eraña H, López-Martínez E, Claes N, Martín VF, Solís DM, Bals S, Cortajarena AL, Castilla J, Liz-Marzán LM, Proceedings of the National Academy of Sciences of the United States of America 115, 3225 (2018). http://doi.org/10.1073/pnas.1721690115
Abstract: Amyloid fibrils, which are closely associated with various neurodegenerative
diseases, are the final products in many protein aggregation pathways. The identification of fibrils at low concentration is, therefore, pivotal in disease diagnosis and development of therapeutic strategies. We report a methodology for the specific identification of amyloid fibrils using chiroptical effects in plasmonic nanoparticles. The formation of amyloid fibrils based on α-synuclein was probed using gold nanorods, which showed no
apparent interaction with monomeric proteins but effective adsorption onto fibril structures via noncovalent interactions. The amyloid structure drives a helical nanorod arrangement, resulting in intense optical activity at the surface plasmon resonance wavelengths. This sensing technique was successfully applied to human brain homogenates of patients affected by Parkinson’s disease,
wherein protein fibrils related to the disease were identified through chiral signals from Au nanorods in the visible and near IR, whereas healthy brain samples did not exhibit any meaningful optical activity. The technique was additionally extended to the specific detection of infectious amyloids formed by prion proteins, thereby confirming the wide potential of the technique. The intense chiral response driven by strong dipolar coupling in helical Au nanorod arrangements allowed us to detect amyloid fibrils down to nanomolar concentrations.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 9.661
Times cited: 187
DOI: 10.1073/pnas.1721690115
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“Division of labor and growth during electrical cooperation in multicellular cable bacteria”. Geerlings NMJ, Karman C, Trashin S, As KS, Kienhuis MVM, Hidalgo-Martinez S, Vasquez-Cardenas D, Boschker HTS, De Wael K, Middelburg JJ, Polerecky L, Meysman FJR, Proceedings Of The National Academy Of Sciences Of The United States Of America 117, 5478 (2020). http://doi.org/10.1073/PNAS.1916244117
Abstract: Multicellularity is a key evolutionary innovation, leading to coordinated activity and resource sharing among cells, which generally occurs via the physical exchange of chemical compounds. However, filamentous cable bacteria display a unique metabolism in which redox transformations in distant cells are coupled via long-distance electron transport rather than an exchange of chemicals. This challenges our understanding of organismal functioning, as the link among electron transfer, metabolism, energy conservation, and filament growth in cable bacteria remains enigmatic. Here, we show that cells within individual filaments of cable bacteria display a remarkable dichotomy in biosynthesis that coincides with redox zonation. Nanoscale secondary ion mass spectrometry combined with 13 C (bicarbonate and propionate) and 15 N-ammonia isotope labeling reveals that cells performing sulfide oxidation in deeper anoxic horizons have a high assimilation rate, whereas cells performing oxygen reduction in the oxic zone show very little or no label uptake. Accordingly, oxygen reduction appears to merely function as a mechanism to quickly dispense of electrons with little to no energy conservation, while biosynthesis and growth are restricted to sulfide-respiring cells. Still, cells can immediately switch roles when redox conditions change, and show no differentiation, which suggests that the “community service” performed by the cells in the oxic zone is only temporary. Overall, our data reveal a division of labor and electrical cooperation among cells that has not been seen previously in multicellular organisms.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 11.1
Times cited: 6
DOI: 10.1073/PNAS.1916244117
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“Insights into the composition of ancient Egyptian red and black inks on papyri achieved by synchrotron-based microanalyses”. Christiansen T, Cotte M, de Nolf W, Mouro E, Reyes-Herrera J, De Meyer S, Vanmeert F, Salvado N, Gonzalez V, Lindelof PE, Mortensen K, Ryholt K, Janssens K, Larsen S, Proceedings Of The National Academy Of Sciences Of The United States Of America 117, 27825 (2020). http://doi.org/10.1073/PNAS.2004534117
Abstract: A hitherto unknown composition is highlighted in the red and black inks preserved on ancient Egyptian papyri from the Roman period (circa 100 to 200 CE). Synchrotron-based macro-X-ray fluo-rescence (XRF) mapping brings to light the presence of iron (Fe) and lead (Pb) compounds in the majority of the red inks inscribed on 12 papyrus fragments from the Tebtunis temple library. The iron-based compounds in the inks can be assigned to ocher, notably due to the colocalization of Fe with aluminum, and the detection of hematite (Fe2O3) by micro-X-ray diffraction. Using the same techniques together with micro-Fourier transform infrared spectroscopy, Pb is shown to be associated with fatty acid phosphate, sulfate, chloride, and carboxylate ions. Moreover, microXRF maps reveal a peculiar distribution and colocalization of Pb, phosphorus (P), and sulfur (S), which are present at the micrometric scale resembling diffused “coffee rings” surrounding the ocher particles imbedded in the red letters, and at the submicrometric scale concentrated in the papyrus cell walls. A similar Pb, P, and S composition was found in three black inks, suggesting that the same lead components were employed in the manufacture of carbon-based inks. Bearing in mind that pigments such as red lead (Pb3O4) and lead white (hydrocerussite [Pb-3(CO3)(2)(OH)(2)] and/or cerussite [PbCO3]) were not detected, the results presented here suggest that the lead compound in the ink was used as a drier rather than as a pigment. Accordingly, the study calls for a reassessment of the composition of lead-based components in ancient Mediterranean pigments.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 11.1
DOI: 10.1073/PNAS.2004534117
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“Rapid automated measurement system for simultaneous determination of effective air-filled porosity and soil gas diffusivity”. Bonroy J, Volckaert M, Seuntjens P, Soil Science Society of America journal 75, 408 (2011). http://doi.org/10.2136/SSSAJ2010.0102
Abstract: The effective air-filled porosity and the gas diffusion coefficient are important soil parameters determining the success of soil bioremediation projects such as (bio)venting and (bio)sparging methods in combination with soil vapor extraction. We have developed a new method to sequentially measure the effective air-filled porosity and the soil gas diffusion coefficient of a soil sample. During the purging of the sample, a fast and accurate measurement of the effective air-filled porosity can be obtained. The subsequent diffusion measurement does not require a zero-O(2) concentration in the soil sample. The procedure further allows the calculation of the soil gas diffusion coefficient before an equilibrium O(2) concentration has been reached. The results are obtained by combining the data of the inlet and outlet compartment in a single equation. A stable reading is reached when the results for the inlet and outlet compartment coincide with the results from the combined equation. The analysis time is reduced by 89 to 96% compared with methods that run until an equilibrium concentration has been reached. Moreover, combining data from inlet and outlet compartments increases the accuracy of the diffusivity measurement by a factor of two compared with previous methods.
Keywords: A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL)
DOI: 10.2136/SSSAJ2010.0102
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“Needle twins and right-angled twins in minerals: comparison between experiment and theory”. Salje EKH, Buckley A, Van Tendeloo G, Ishibashi Y, Nord GL, The American mineralogist 83, 811 (1998)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.021
Times cited: 43
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“A synchrotron radiation, HRTEM, X-ray powder diffraction, and Raman spectroscopic study of malayaite, CaSnSiO5”. Groat LA, Kek S, Bismayer U, Schmidt C, Krane HG, Meyer H, Nistor L, Van Tendeloo G, The American mineralogist 81, 595 (1996)
Abstract: Synchrotron radiation, high-resolution transmission electron microscopy (HRTEM), X-ray powder diffraction, and Raman spectroscopy were used to study the structure and thermal behavior of malayaite, CaSnSiO5. No indications of deviation from A2/a symmetry and no structural transitions were observed between 100 and 870 K. HRTEM revealed that the material is free of domains and antiphase boundaries. However, the lattice constants, cell volume, and Raman-active phonons show a thermal discontinuity near 500 K, which is possibly related to variation of the coordination sphere around the highly anisotropic Ca position.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 1.964
Times cited: 19
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“Two generations of exsolution lamellae in pyroxene from Asuka 09545 : Clues to the thermal evolution of silicates in mesosiderite”. Pittarello L, Mckibbin S, Yamaguchi A, Ji G, Schryvers D, Debaille V, Claeys P, The American mineralogist 104, 1663 (2019). http://doi.org/10.2138/AM-2019-7001
Abstract: Mesosiderite meteorites consist of a mixture of crustal basaltic or gabbroic material and metal. Their formation process is still debated due to their unexpected combination of crust and core materials, possibly derived from the same planetesimal parent body, and lacking an intervening mantle component. Mesosiderites have experienced an extremely slow cooling rate from ca. 550 degrees C, as recorded in the metal (0.25-0.5 degrees C/Ma). Here we present a detailed investigation of exsolution features in pyroxene from the Antarctic mesosiderite Asuka (A) 09545. Geothermobarometry calculations, lattice parameters, lamellae orientation, and the presence of clinoenstatite as the host were used in an attempt to constrain the evolution of pyroxene from 1150 to 570 degrees C and the formation of two generations of exsolution lamellae. After pigeonite crystallization at ca. 1150 degrees C, the first exsolution process generated the thick augite lamellae along (100) in the temperature interval 1000-900 degrees C. By further cooling, a second order of exsolution lamellae formed within augite along (001), consisting of monoclinic low-Ca pyroxene, equilibrated in the temperature range 900-800 degrees C. The last process, occurring in the 600-500 degrees C temperature range, was likely the inversion of high to low pigeonite in the host crystal, lacking evidence for nucleation of orthopyroxene. The formation of two generations of exsolution lamellae, as well as of likely metastable pigeonite, suggest non-equilibrium conditions. Cooling was sufficiently slow to allow the formation of the lamellae, their preservation, and the transition from high to low pigeonite. In addition, the preservation of such fine-grained lamellae limits long-lasting, impact reheating to a peak temperature lower than 570 degrees C. These features, including the presence of monoclinic low-Ca pyroxene as the host, are reported in only a few mesosiderites. This suggests a possibly different origin and thermal history from most mesosiderites and that the crystallography (i.e., space group) of low-Ca pyroxene could be used as parameter to distinguish mesosiderite populations based on their cooling history.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.021
DOI: 10.2138/AM-2019-7001
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“Elemental analysis of aerosol-size fractions by proton-induced X-ray-emission”. Johansson TB, Nelson JW, Van Grieken RE, Winchester JW, Transactions of the American Nuclear Society 17, 103 (1973)
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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