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Meyer FW, Schubert N, Diele K, Teichberg M, Wild C, Enríquez S. Effect of Inorganic and Organic Carbon Enrichments (DIC and DOC) on the Photosynthesis and Calcification Rates of Two Calcifying Green Algae from a Caribbean Reef Lagoon. PLoS One 2016; 11:e0160268. [PMID: 27487195 PMCID: PMC4972524 DOI: 10.1371/journal.pone.0160268] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 07/15/2016] [Indexed: 11/18/2022] Open
Abstract
Coral reefs worldwide are affected by increasing dissolved inorganic carbon (DIC) and organic carbon (DOC) concentrations due to ocean acidification (OA) and coastal eutrophication. These two stressors can occur simultaneously, particularly in near-shore reef environments with increasing anthropogenic pressure. However, experimental studies on how elevated DIC and DOC interact are scarce and fundamental to understanding potential synergistic effects and foreseeing future changes in coral reef function. Using an open mesocosm experiment, the present study investigated the impact of elevated DIC (pHNBS: 8.2 and 7.8; pCO2: 377 and 1076 μatm) and DOC (added as 833 μmol L-1 of glucose) on calcification and photosynthesis rates of two common calcifying green algae, Halimeda incrassata and Udotea flabellum, in a shallow reef environment. Our results revealed that under elevated DIC, algal photosynthesis decreased similarly for both species, but calcification was more affected in H. incrassata, which also showed carbonate dissolution rates. Elevated DOC reduced photosynthesis and calcification rates in H. incrassata, while in U. flabellum photosynthesis was unaffected and thalus calcification was severely impaired. The combined treatment showed an antagonistic effect of elevated DIC and DOC on the photosynthesis and calcification rates of H. incrassata, and an additive effect in U. flabellum. We conclude that the dominant sand dweller H. incrassata is more negatively affected by both DIC and DOC enrichments, but that their impact could be mitigated when they occur simultaneously. In contrast, U. flabellum can be less affected in coastal eutrophic waters by elevated DIC, but its contribution to reef carbonate sediment production could be further reduced. Accordingly, while the capacity of environmental eutrophication to exacerbate the impact of OA on algal-derived carbonate sand production seems to be species-specific, significant reductions can be expected under future OA scenarios, with important consequences for beach erosion and coastal sediment dynamics.
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Affiliation(s)
| | - Nadine Schubert
- Laboratory of Photobiology, Unidad Académica de Sistemas Arrecifales Puerto Morelos (ICMyL), Universidad Nacional Autónoma de México (UNAM), Cancún, Mexico
| | - Karen Diele
- Edinburgh Napier University, School of Life, Sport and Social Sciences, EH11 4BN Edinburgh, United Kingdom
- St Abbs Marine Station, St Abbs, Berwickshire, TD14 5QF, United Kingdom
| | - Mirta Teichberg
- Leibniz Center for Tropical Marine Ecology (ZMT), Bremen, Germany
| | - Christian Wild
- Leibniz Center for Tropical Marine Ecology (ZMT), Bremen, Germany
- Faculty of Biology & Chemistry, University of Bremen, Bibliothekstraße 1, Bremen, Germany
| | - Susana Enríquez
- Laboratory of Photobiology, Unidad Académica de Sistemas Arrecifales Puerto Morelos (ICMyL), Universidad Nacional Autónoma de México (UNAM), Cancún, Mexico
- * E-mail: ;
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Meyer FW, Krstic PS, Hijazi H, Bannister ME, Dadras J, Parish CM, Meyer HM. Surface-morphology changes and damage in hot tungsten by impact of 80 eV – 12 keV He-ions and keV-energy self-atoms. ACTA ACUST UNITED AC 2014. [DOI: 10.1088/1742-6596/488/1/012036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
We describe a large-acceptance deceleration module capable of decelerating large-emittance full-intensity ion beams typical of ECR ion sources to very low energies with high efficiency. The deceleration module is designed to permit convenient retrofitting into an existing beam line to replace, e.g., the first Faraday cup after magnetic analysis of the beam extracted from the ion source. For starting energies of 10 keV, and incident ion currents as large as 300 μA, deceleration efficiencies have been measured to be greater than 80% for final energies as low as 70 eV. The decelerated beam intensity can be monitored either by insertion of a beam catcher floating at the final deceleration voltage or from the current to the exit grid itself, with suitable correction applied for the grid transparency factor. The behavior of the deceleration optics was modeled using SIMION, incorporating the effects of intra-beam space charge repulsion. We describe a recent application of this deceleration module to study near-surface He bubble and blister formation of a W target heated to 1250 K and irradiated with a 98 eV He ion beam with a flux of ∼10(16) cm(-2) s(-1).
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Affiliation(s)
- H Hijazi
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6372, USA
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Harris PR, Meyer FW. Plasma potential and energy spread determination using ion beams extracted from an electron cyclotron resonance source. Rev Sci Instrum 2010; 81:02A310. [PMID: 20192331 DOI: 10.1063/1.3272847] [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] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We have obtained estimates of plasma potentials and energy spreads characterizing an electron cyclotron resonance ion source plasma under different source conditions. Our estimates are obtained from analysis of ion beams extracted from the ion source at 10 kV that are subsequently decelerated into a floating surface scattering chamber where their current intensity incident on a solid sample is measured as function of retardation voltage. The deceleration occurs outside the measurement chamber, permitting beam current measurements in a field-free region. Absence of grids in the deceleration section avoids potential issues of field penetration. The behavior of our deceleration optics was modeled with SIMION. The simulation indicated a linear beam attenuation dependence close to full retardation where the beam current goes to zero. Deviations from this linear dependence observed close to zero beam energy give information on the initial energy spread of the ions extracted from the source. Our decelerated beams measurements are compared with recent in situ probe results and external beams results based on magnetic analysis.
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Affiliation(s)
- P R Harris
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6372, USA.
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You HJ, Woo HJ, Chung KS, Liu Y, Meyer FW, Lho T, Lee MJ. Deduction of edge electron density with multiply charged ions in ORNL volume-type electron cyclotron resonance ion source. Rev Sci Instrum 2008; 79:02A319. [PMID: 18315109 DOI: 10.1063/1.2816911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The electron densities in the argon plasmas of the ORNL 6 GHz electron cyclotron resonance (ECR) ion source with a flat central magnetic field have been deduced from the ion branches of the electric probe current-voltage curves measured in the edge region of the plasmas. To overcome the difficulties due to unknown velocities of multiply charged ions at the sheath edge, a modified generalized Bohm criterion for the ion sheath velocity is introduced and the mean velocity of all ionic charge states at the sheath edge is assumed to be equal to the sound velocity of the system of particles. The calculated electron densities and temperatures for different plasmas optimized for four charge state distributions are discussed.
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Affiliation(s)
- H-J You
- Electric Probe Applications Laboratory, Hanyang University, Seoul, Republic of Korea
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Morozov VA, Meyer FW. Path-dependent neutralization of multiply charged Ar ions incident on Au(110). Phys Rev Lett 2001; 86:736-739. [PMID: 11177925 DOI: 10.1103/physrevlett.86.736] [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] [Subscribe] [Scholar Register] [Received: 06/08/2000] [Indexed: 05/23/2023]
Abstract
Using a time-of-flight technique we have investigated the backscattering of 5 keV Ar(2+) and Ar(11+) projectiles from Au(110). A strong dependence on target azimuth is found for the neutral flux resulting from (quasi)binary projectile collisions with target atoms, while for the charged components only a weak dependence is seen. A deconvolution of the observed dependences based on trajectory simulations clearly shows site-specific neutralization differences between the various possible binary collisions occurring with surface atoms. Such differences must be properly accounted for in order to permit meaningful comparison with theory.
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Affiliation(s)
- V A Morozov
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6372, USA
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Phaneuf RA, Meyer FW, McKnight RH, Olson RE, Salop A. Electron-capture and impact-ionisation cross sections of Nq+in atomic hydrogen. ACTA ACUST UNITED AC 2001. [DOI: 10.1088/0022-3700/10/11/003] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Yan Q, Zehner DM, Meyer FW, Schippers S. Projectile velocity and target temperature dependence of charge-state distributions of multicharged ions scattered during grazing interactions with a Au(110) surface. Phys Rev A 1996; 54:641-648. [PMID: 9913518 DOI: 10.1103/physreva.54.641] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Bannister ME, Meyer FW, Chung YS, Djuric N, Dunn GH, Pindzola MS, Griffin DC. Absolute cross sections for the electron-impact single ionization of Mo4+ and Mo5+ ions. Phys Rev A 1995; 52:413-419. [PMID: 9912263 DOI: 10.1103/physreva.52.413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Folkerts L, Schippers S, Zehner DM, Meyer FW. Time scales for charge equilibration of Oq+ (3 <= q <= 8) ions during surface-channeling interactions with Au(110). Phys Rev Lett 1995; 74:2204-2207. [PMID: 10057869 DOI: 10.1103/physrevlett.74.2204] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Meyer FW, Folkerts L, Hughes IG, Overbury SH, Zehner DM, Burgdörfer J. Work-function dependence of above-surface neutralization of multicharged ions. Phys Rev A 1993; 48:4479-4484. [PMID: 9910152 DOI: 10.1103/physreva.48.4479] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Meyer FW, Havener CC. Above-surface neutralization of slow N6+ ions during interactions with a Cu(001) target. Phys Rev A 1993; 48:4476-4478. [PMID: 9910151 DOI: 10.1103/physreva.48.4476] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Hughes IG, Burgdörfer J, Folkerts L, Havener CC, Overbury SH, Robinson MT, Zehner DM, Meyer FW. Separation of kinetic and potential electron emission arising from slow multicharged ion-surface interactions. Phys Rev Lett 1993; 71:291-294. [PMID: 10054912 DOI: 10.1103/physrevlett.71.291] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Havener CC, Hughes IG, Zehner DM, Meyer FW. Emission of low-energy electrons from multicharged ions interacting with metal surfaces. Phys Rev A 1993; 47:3998-4006. [PMID: 9909407 DOI: 10.1103/physreva.47.3998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Meyer FW, Overbury SH, Havener CC, Burgdörfer J, Zehner DM. Electron emission during interactions of multicharged N and Ar ions with Au(110) and Cu(001) surfaces. Phys Rev A 1991; 44:7214-7228. [PMID: 9905863 DOI: 10.1103/physreva.44.7214] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Burgdörfer J, Lerner P, Meyer FW. Above-surface neutralization of highly charged ions: The classical over-the-barrier model. Phys Rev A 1991; 44:5674-5685. [PMID: 9906628 DOI: 10.1103/physreva.44.5674] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Meyer FW, Overbury SH, Havener CC, Zehner DM. Evidence for above-surface and subsurface neutralization during interactions of highly charged ions with a metal target. Phys Rev Lett 1991; 67:723-726. [PMID: 10044972 DOI: 10.1103/physrevlett.67.723] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Swenson JK, Burgdörfer J, Meyer FW, Havener CC, Gregory DC, Stolterfoht N. Coulomb "path" interference in low-energy ion-atom collisions. Phys Rev Lett 1991; 66:417-420. [PMID: 10043802 DOI: 10.1103/physrevlett.66.417] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Stolterfoht N, Sommer K, Swenson JK, Havener CC, Meyer FW. Electron-correlation effects in double-electron-capture collisions of 60-keV C6+ with He. Phys Rev A 1990; 42:5396-5405. [PMID: 9904674 DOI: 10.1103/physreva.42.5396] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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Gregory DC, Huq MS, Meyer FW, Swenson DR, Sataka M, Chantrenne S. Electron-impact ionization cross-section measurements for U10+, U13+, and U16+. Phys Rev A 1990; 41:106-115. [PMID: 9902848 DOI: 10.1103/physreva.41.106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Swenson JK, Havener CC, Stolterfoht N, Sommer K, Meyer FW. Observation of Coulomb focusing of autoionization electrons produced in low-energy He++He collisions. Phys Rev Lett 1989; 63:35-38. [PMID: 10040426 DOI: 10.1103/physrevlett.63.35] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Snowdon KJ, Havener CC, Meyer FW, Overbury SH, Zehner DM, Heiland W. Charge exchange at molecular-orbital pseudocrossings as an important mechanism for nonkinetic-electron emission in slow-multicharged-ion (v<v0) metal-surface scattering. Phys Rev A Gen Phys 1988; 38:2294-2304. [PMID: 9900636 DOI: 10.1103/physreva.38.2294] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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Meyer FW, Griffin DC, Havener CC, Huq MS, Phaneuf RA, Swenson JK, Stolterfoht N. Population of high-angular-momentum states in low-energy double-electron-capture collisions of O6+ with He. Phys Rev Lett 1988; 60:1821-1824. [PMID: 10038149 DOI: 10.1103/physrevlett.60.1821] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Waggoner W, Cocke CL, Tunnell LN, Havener CC, Meyer FW, Phaneuf RA. Angular distributions for electron capture from He by multiply charged C, N, O, F, and Ne ions. Phys Rev A Gen Phys 1988; 37:2386-2392. [PMID: 9899944 DOI: 10.1103/physreva.37.2386] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Gregory DC, Wang LJ, Meyer FW, Rinn K. Electron-impact ionization of iron ions: Fe11+, Fe13+, and Fe15+. Phys Rev A Gen Phys 1987; 35:3256-3264. [PMID: 9898541 DOI: 10.1103/physreva.35.3256] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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Meyer FW, Havener CC, Snowdon KJ, Overbury SH, Zehner AD, Heiland W. Observation of the neutralization of highly charged ions interacting with a metal surface. Phys Rev A Gen Phys 1987; 35:3176-3179. [PMID: 9898532 DOI: 10.1103/physreva.35.3176] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Gregory DC, Meyer FW, Müller A, Defrance P. Experimental cross sections for electron-impact ionization of iron ions: Fe5+, Fe6+, and Fe9+. Phys Rev A Gen Phys 1986; 34:3657-3667. [PMID: 9897707 DOI: 10.1103/physreva.34.3657] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Stolterfoht N, Havener CC, Phaneuf RA, Swenson JK, Shafroth SM, Meyer FW. Evidence for correlated double-electron capture in low-energy collisions of O6+ with He. Phys Rev Lett 1986; 57:74-77. [PMID: 10033361 DOI: 10.1103/physrevlett.57.74] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Howald AM, Gregory DC, Meyer FW, Phaneuf RA, Müller A, Djuric N, Dunn GH. Electron-impact ionization of Mg-like ions: S4+, Cl5+, and Ar6+. Phys Rev A Gen Phys 1986; 33:3779-3786. [PMID: 9897119 DOI: 10.1103/physreva.33.3779] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Meyer FW, Howald AM, Havener CC, Phaneuf RA. Low-energy total-electron-capture cross sections for fully stripped and H-like projectiles incident on H and H2. Phys Rev A Gen Phys 1985; 32:3310-3318. [PMID: 9896498 DOI: 10.1103/physreva.32.3310] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Meyer FW, Howald AM, Havener CC, Phaneuf RA. Observation of low-energy Z oscillations in total electron-capture cross sections for bare projectiles colliding with H and H2. Phys Rev Lett 1985; 54:2663-2666. [PMID: 10031405 DOI: 10.1103/physrevlett.54.2663] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Meyer FW, Sayegh FS. Wound healing following curettement of bifurcation abscesses of human primary molars. Oral Surg Oral Med Oral Pathol 1979; 47:267-74. [PMID: 283356 DOI: 10.1016/0030-4220(79)90152-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Forty-five abscessed human mandibular primary molars with bifurcation radiolucency were subjected to a two-stage formocresol treatment of the pulp chamber. On the first appointment, an elliptical patch of buccal mucosa was removed. Bony defects varied from 2 mm. to more than 4 mm. in diameter. Periapical radiographs were used to record changes in bone development. Punch biopsy specimens were taken from the bifurcation area of some subjects from 2 weeks up to a year after surgical curettement. Biopsied tissue was studied by electron and light microscopy to examine wound healing of the bifurcation, revealing an early proliferation of fibroblasts with extracellular collagen fibers. Some of the fibroblasts exhibited an extensive network of rough endoplasmic reticulum, scattered free ribosomes, mitochondria, and other organelles which are normally observed in healthy fibroblasts. Histologic and clinical evaluation support the treatment tested for retention of previously abscessed primary molars.
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Meyer FW. [Diagnostic problems of mouth carcinoma]. Zentralbl Chir 1969; 94:414-20. [PMID: 5370948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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