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Liu X, Domier CW, Dannenberg J, Zhu Y, Sirigiri JR, Ren Y, Stratton B, Luhmann NC. The National Spherical Torus Experiment-Upgrade poloidal high-k scattering system pitch angle design modifications. Rev Sci Instrum 2022; 93:103509. [PMID: 36319363 DOI: 10.1063/5.0099912] [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: 05/19/2022] [Accepted: 08/23/2022] [Indexed: 06/16/2023]
Abstract
A 693 GHz, eight-channel, poloidal high-k (k refers to wavenumber) collective scattering system is under development for the National Spherical Torus Experiment-Upgrade device. It will replace the previous 280 GHz, five-channel, tangential scattering system to study high-k electron density fluctuations, thereby providing a measurement of the kθ-spectrum of both electron temperature gradient and ion temperature gradient modes. A tool is under development to calculate the wavenumber that exists in the presence of strong magnetic pitch angles. We use this tool to motivate a new receiver optical design for significantly improved performance, details of which are presented herein.
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Affiliation(s)
- X Liu
- University of California at Davis, 1 Shields Ave., Davis, California 95616, USA
| | - C W Domier
- University of California at Davis, 1 Shields Ave., Davis, California 95616, USA
| | - J Dannenberg
- University of California at Davis, 1 Shields Ave., Davis, California 95616, USA
| | - Y Zhu
- University of California at Davis, 1 Shields Ave., Davis, California 95616, USA
| | - J R Sirigiri
- Bridge 12 Technologies, Inc., 37 Loring Drive, Framingham, Massachusetts 01702, USA
| | - Y Ren
- Princeton Plasma Physics Laboratory, 100 Stellarator Rd., Princeton, New Jersey 08540, USA
| | - B Stratton
- Princeton Plasma Physics Laboratory, 100 Stellarator Rd., Princeton, New Jersey 08540, USA
| | - N C Luhmann
- University of California at Davis, 1 Shields Ave., Davis, California 95616, USA
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Domier CW, Zhu Y, Dannenberg J, Luhmann NC. A next generation ultra short pulse reflectometry (USPR) diagnostic. Rev Sci Instrum 2021; 92:034714. [PMID: 33820035 DOI: 10.1063/5.0040724] [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] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 02/28/2021] [Indexed: 06/12/2023]
Abstract
Ultrashort Pulse Reflectometry (USPR) is a plasma diagnostic technique involving the propagation and reflection of ultrashort duration (∼few ns) chirps. The reflected packets pass through a multichannel filter with time-of-flight measurements performed on each of the filtered packets. A next generation USPR system is under development, spanning 28-75 GHz, for use on compact, short duration, magnetically confined fusion devices. This system presents a dramatic increase in performance compared with an earlier USPR system employed on the LLNL Sustained Spheromak Physics Experiment device more than a decade ago. The new system replaces upconverting mixers with higher power active multiplier chains to generate mm-wave transmitter chirps, with custom time-of-flight electronics reducing the time per measurement by a factor of 3X. Finally, the system is equipped with a field programmable gate array for data acquisition and analysis.
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Affiliation(s)
- C W Domier
- Department of Electrical and Computer Engineering, University of California at Davis, Davis, California 95616, USA
| | - Y Zhu
- Department of Electrical and Computer Engineering, University of California at Davis, Davis, California 95616, USA
| | - J Dannenberg
- Department of Electrical and Computer Engineering, University of California at Davis, Davis, California 95616, USA
| | - N C Luhmann
- Department of Electrical and Computer Engineering, University of California at Davis, Davis, California 95616, USA
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Vlaming H, McLean CM, Korthout T, Alemdehy MF, Hendriks S, Lancini C, Palit S, Klarenbeek S, Kwesi‐Maliepaard EM, Molenaar TM, Hoekman L, Schmidlin TT, Altelaar AFM, van Welsem T, Dannenberg J, Jacobs H, van Leeuwen F. Conserved crosstalk between histone deacetylation and H3K79 methylation generates DOT1L-dose dependency in HDAC1-deficient thymic lymphoma. EMBO J 2019; 38:e101564. [PMID: 31304633 PMCID: PMC6627229 DOI: 10.15252/embj.2019101564] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 05/20/2019] [Accepted: 05/24/2019] [Indexed: 12/12/2022] Open
Abstract
DOT1L methylates histone H3K79 and is aberrantly regulated in MLL-rearranged leukemia. Inhibitors have been developed to target DOT1L activity in leukemia, but cellular mechanisms that regulate DOT1L are still poorly understood. We have identified the histone deacetylase Rpd3 as a negative regulator of budding yeast Dot1. At its target genes, the transcriptional repressor Rpd3 restricts H3K79 methylation, explaining the absence of H3K79me3 at a subset of genes in the yeast genome. Similar to the crosstalk in yeast, inactivation of the murine Rpd3 homolog HDAC1 in thymocytes led to an increase in H3K79 methylation. Thymic lymphomas that arise upon genetic deletion of Hdac1 retained the increased H3K79 methylation and were sensitive to reduced DOT1L dosage. Furthermore, cell lines derived from Hdac1Δ/Δ thymic lymphomas were sensitive to a DOT1L inhibitor, which induced apoptosis. In summary, we identified an evolutionarily conserved crosstalk between HDAC1 and DOT1L with impact in murine thymic lymphoma development.
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Affiliation(s)
- Hanneke Vlaming
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
- Present address:
Department of Biological Chemistry and Molecular PharmacologyHarvard Medical SchoolBostonMAUSA
| | - Chelsea M McLean
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Tessy Korthout
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Mir Farshid Alemdehy
- Division of Tumor Biology & ImmunologyNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Sjoerd Hendriks
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Cesare Lancini
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Sander Palit
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Sjoerd Klarenbeek
- Experimental Animal PathologyNetherlands Cancer InstituteAmsterdamThe Netherlands
| | | | - Thom M Molenaar
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Liesbeth Hoekman
- Experimental Animal PathologyNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Thierry T Schmidlin
- Biomolecular Mass Spectrometry and ProteomicsBijvoet Center for Biomolecular ResearchUtrecht Institute for Pharmaceutical SciencesUtrecht University and Netherlands Proteomics CentreUtrechtThe Netherlands
| | - AF Maarten Altelaar
- Biomolecular Mass Spectrometry and ProteomicsBijvoet Center for Biomolecular ResearchUtrecht Institute for Pharmaceutical SciencesUtrecht University and Netherlands Proteomics CentreUtrechtThe Netherlands
- Proteomics FacilityNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Tibor van Welsem
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Jan‐Hermen Dannenberg
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
- Present address:
Genmab B.V.Antibody SciencesUtrechtThe Netherlands
| | - Heinz Jacobs
- Division of Tumor Biology & ImmunologyNetherlands Cancer InstituteAmsterdamThe Netherlands
| | - Fred van Leeuwen
- Division of Gene RegulationNetherlands Cancer InstituteAmsterdamThe Netherlands
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Barchfeld R, Domier CW, Ren Y, Ellis R, Riemenschneider P, Allen N, Kaita R, Stratton B, Dannenberg J, Zhu Y, Luhmann NC. The high- k poloidal scattering system for NSTX-U. Rev Sci Instrum 2018; 89:10C114. [PMID: 30399655 DOI: 10.1063/1.5035410] [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: 04/15/2018] [Accepted: 06/25/2018] [Indexed: 06/08/2023]
Abstract
An 8-channel, high-k poloidal far-infrared (FIR) scattering system is under development for the National Spherical Torus eXperiment Upgrade (NSTX-U). The 693 GHz poloidal scattering system replaces a 5-channel, 280 GHz high-k toroidal scattering system to study high-k electron density fluctuations on NSTX-U. The FIR probe beam launched from Bay G is aimed toward Bay L, where large aperture optics collect radiation at 8 simultaneous scattering angles ranging from 2° to 15°. The reduced wavelength in the poloidal system results in less refraction, and coupled with a new poloidal scattering geometry, extends measurement of poloidal wavenumbers from the previous limit of 7 cm-1 up to >40 cm-1. Steerable launch optics coupled with receiver optics that can be remotely translated in 5 axes allow the scattering volume to be placed from r/a = 0.1 out to the pedestal region (r/a ∼ 0.99) and allow for both upward and downward scattering to cover different regions of the 2D fluctuation spectrum.
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Affiliation(s)
- R Barchfeld
- Department of Electrical and Computer Engineering, University of California, Davis, California 95616, USA
| | - C W Domier
- Department of Electrical and Computer Engineering, University of California, Davis, California 95616, USA
| | - Y Ren
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - R Ellis
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - P Riemenschneider
- Department of Electrical and Computer Engineering, University of California, Davis, California 95616, USA
| | - N Allen
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - R Kaita
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - B Stratton
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - J Dannenberg
- Department of Electrical and Computer Engineering, University of California, Davis, California 95616, USA
| | - Y Zhu
- Department of Electrical and Computer Engineering, University of California, Davis, California 95616, USA
| | - N C Luhmann
- Department of Electrical and Computer Engineering, University of California, Davis, California 95616, USA
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Li JX, Zhu YL, Chen M, Cao JH, Dannenberg J, Domier C, Luhmann NC. A new method of out-of-focus millimeter wave imaging in fusion plasma diagnostics using Bessel beams. Rev Sci Instrum 2018; 89:093506. [PMID: 30278691 DOI: 10.1063/1.5012778] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 08/26/2018] [Indexed: 06/08/2023]
Abstract
Electron cyclotron emission imaging (ECEI) and microwave imaging reflectometry diagnostics have been employed on a number of magnetic fusion plasma confinement devices. The common approach is based on a Gaussian beam assumption, which generates good spatial resolution (centimeter level). However, the radial focal depth is limited by the poloidal resolution, which is comparable with the Rayleigh length (∼150 mm). By contrast, a new Bessel beam approach has been developed and demonstrated to generate much longer focal depth with the property of propagation stability. To test the new approach, the DIII-D tokamak LCP ECEI optics have been re-designed to support a Bessel beam approach based on an axicon lens. The achievable radial coverage can exceed that of the current Gaussian approach by 3×. The imaging result is discussed in this paper based on the simulation analysis and laboratory testing result.
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Affiliation(s)
- J X Li
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Y L Zhu
- University of California at Davis, Davis, California 95616, USA
| | - M Chen
- University of California at Davis, Davis, California 95616, USA
| | - J H Cao
- University of California at Davis, Davis, California 95616, USA
| | - J Dannenberg
- University of California at Davis, Davis, California 95616, USA
| | - C Domier
- University of California at Davis, Davis, California 95616, USA
| | - N C Luhmann
- University of California at Davis, Davis, California 95616, USA
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Dannenberg J. Performance evaluation of real-time PCR based assays for the detection and quantitation of hepatitis B virus DNA. J Clin Virol 2006. [PMCID: PMC7128834 DOI: 10.1016/s1386-6532(06)80715-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Bähring R, Dannenberg J, Peters HC, Leicher T, Pongs O, Isbrandt D. Conserved Kv4 N-terminal domain critical for effects of Kv channel-interacting protein 2.2 on channel expression and gating. J Biol Chem 2001; 276:23888-94. [PMID: 11287421 DOI: 10.1074/jbc.m101320200] [Citation(s) in RCA: 171] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Association of Kv channel-interacting proteins (KChIPs) with Kv4 channels leads to modulation of these A-type potassium channels (An, W. F., Bowlby, M. R., Betty, M., Cao, J., Ling, H. P., Mendoza, G., Hinson, J. W., Mattsson, K. I., Strassle, B. W., Trimmer, J. S., and Rhodes, K. J. (2000) Nature 403, 553-556). We cloned a KChIP2 splice variant (KChIP2.2) from human ventricle. In comparison with KChIP2.1, coexpression of KChIP2.2 with human Kv4 channels in mammalian cells slowed the onset of Kv4 current inactivation (2-3-fold), accelerated the recovery from inactivation (5-7-fold), and shifted Kv4 steady-state inactivation curves by 8-29 mV to more positive potentials. The features of Kv4.2/KChIP2.2 currents closely resemble those of cardiac rapidly inactivating transient outward currents. KChIP2.2 stimulated the Kv4 current density in Chinese hamster ovary cells by approximately 55-fold. This correlated with a redistribution of immunoreactivity from perinuclear areas to the plasma membrane. Increased Kv4 cell-surface expression and current density were also obtained in the absence of KChIP2.2 when the highly conserved proximal Kv4 N terminus was deleted. The same domain is required for association of KChIP2.2 with Kv4 alpha-subunits. We propose that an efficient transport of Kv4 channels to the cell surface depends on KChIP binding to the Kv4 N-terminal domain. Our data suggest that the binding is necessary, but not sufficient, for the functional activity of KChIPs.
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Affiliation(s)
- R Bähring
- Institut für Neurale Signalverarbeitung, Zentrum für Molekulare Neurobiologie, Universität Hamburg, Martinistrasse 52, 20246 Hamburg, Germany
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Bähring R, Milligan CJ, Vardanyan V, Engeland B, Young BA, Dannenberg J, Waldschutz R, Edwards JP, Wray D, Pongs O. Coupling of voltage-dependent potassium channel inactivation and oxidoreductase active site of Kvbeta subunits. J Biol Chem 2001; 276:22923-9. [PMID: 11294861 DOI: 10.1074/jbc.m100483200] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The accessory beta subunits of voltage-dependent potassium (Kv) channels form tetramers arranged with 4-fold rotational symmetry like the membrane-integral and pore-forming alpha subunits (Gulbis, J. M., Mann, S., and MacKinnon, R. (1999) Cell. 90, 943-952). The crystal structure of the Kvbeta2 subunit shows that Kvbeta subunits are oxidoreductase enzymes containing an active site composed of conserved catalytic residues, a nicotinamide (NADPH)-cofactor, and a substrate binding site. Also, Kvbeta subunits with an N-terminal inactivating domain like Kvbeta1.1 (Rettig, J., Heinemann, S. H., Wunder, F., Lorra, C., Parcej, D. N., Dolly, O., and Pongs, O. (1994) Nature 369, 289-294) and Kvbeta3.1 (Heinemann, S. H., Rettig, J., Graack, H. R., and Pongs, O. (1996) J. Physiol. (Lond.) 493, 625-633) confer rapid N-type inactivation to otherwise non-inactivating channels. Here we show by a combination of structural modeling and electrophysiological characterization of structure-based mutations that changes in Kvbeta oxidoreductase activity may markedly influence the gating mode of Kv channels. Amino acid substitutions of the putative catalytic residues in the Kvbeta1.1 oxidoreductase active site attenuate the inactivating activity of Kvbeta1.1 in Xenopus oocytes. Conversely, mutating the substrate binding domain and/or the cofactor binding domain rescues the failure of Kvbeta3.1 to confer rapid inactivation to Kv1.5 channels in Xenopus oocytes. We propose that Kvbeta oxidoreductase activity couples Kv channel inactivation to cellular redox regulation.
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Affiliation(s)
- R Bähring
- Institut für Neurale Signalverarbeitung, Zentrum für Molekulare Neurobiologie der Universität Hamburg, Hamburg, Germany
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Bourne Y, Dannenberg J, Pollmann V, Marchot P, Pongs O. Immunocytochemical localization and crystal structure of human frequenin (neuronal calcium sensor 1). J Biol Chem 2001; 276:11949-55. [PMID: 11092894 DOI: 10.1074/jbc.m009373200] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Frequenin, a member of a large family of myristoyl-switch calcium-binding proteins, functions as a calcium-ion sensor to modulate synaptic activity and secretion. We show that human frequenin colocalizes with ARF1 GTPase in COS-7 cells and occurs in similar cellular compartments as the phosphatidylinositol-4-OH kinase PI4Kbeta, the mammalian homolog of the yeast kinase PIK1. In addition, the crystal structure of unmyristoylated, calcium-bound human frequenin has been determined and refined to 1.9 A resolution. The overall fold of frequenin resembles those of neurocalcin and the photoreceptor, recoverin, of the same family, with two pairs of calcium-binding EF hands and three bound calcium ions. Despite the similarities, however, frequenin displays significant structural differences. A large conformational shift of the C-terminal region creates a wide hydrophobic crevice at the surface of frequenin. This crevice, which is unique to frequenin and distinct from the myristoyl-binding box of recoverin, may accommodate a yet unknown protein ligand.
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Affiliation(s)
- Y Bourne
- Architecture et Fonction des Macromolécules Biologiques, CNRS UMR-6098, 13402, Marseille Cedex 20, France.
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Meng W, Meng S, Männchen E, Hampel R, Kirsch G, Dannenberg J, Krabbe S. Effect of therapy duration and low and highly dosed thiamazole treatment in Basedow's-Graves' disease. Exp Clin Endocrinol 1991; 97:257-60. [PMID: 1915642 DOI: 10.1055/s-0029-1211074] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- W Meng
- Klinik für Innere Medizin, Ernst-Moritz-Arndt-Universität Greifswald
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Dannenberg J, Castano FA. A review of the treatment of traumatized anterior teeth. J N J Dent Assoc 1972; 43:10-3 passim. [PMID: 4501334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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