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Mondal S, Chowdhury U, Dey S, Habib M, Mora Perez C, Frauenheim T, Sarkar R, Pal S, Prezhdo OV. Controlling Charge Carrier Dynamics in Porphyrin Nanorings by Optically Active Templates. J Phys Chem Lett 2023; 14:11384-11392. [PMID: 38078872 PMCID: PMC10749466 DOI: 10.1021/acs.jpclett.3c03304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/01/2023] [Accepted: 12/01/2023] [Indexed: 12/22/2023]
Abstract
Understanding the dynamics of photogenerated charge carriers is essential for enhancing the performance of solar and optoelectronic devices. Using atomistic quantum dynamics simulations, we demonstrate that a short π-conjugated optically active template can be used to control hot carrier relaxation, charge carrier separation, and carrier recombination in light-harvesting porphyrin nanorings. Relaxation of hot holes is slowed by 60% with an optically active template compared to that with an analogous optically inactive template. Both systems exhibit subpicosecond electron transfer from the photoactive core to the templates. Notably, charge recombination is suppressed 6-fold by the optically active template. The atomistic time-domain simulations rationalize these effects by the extent of electron and hole localization, modification of the density of states, participation of distinct vibrational motions, and changes in quantum coherence. Extension of the hot carrier lifetime and reduction of charge carrier recombination, without hampering charge separation, demonstrate a strategy for enhancing efficiencies of energy materials with optically active templates.
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Affiliation(s)
- Shrabanti Mondal
- Department
of Chemistry, University of Gour Banga, Malda 732103, India
| | - Uttam Chowdhury
- Department
of Chemistry, University of Gour Banga, Malda 732103, India
| | - Subhajit Dey
- Department
of Chemistry, University of Gour Banga, Malda 732103, India
| | - Md Habib
- Department
of Chemistry, University of Gour Banga, Malda 732103, India
- Department
of Chemistry, Sripat Singh College, Jiaganj 742122, India
| | - Carlos Mora Perez
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Thomas Frauenheim
- Bremen
Center
for Computational Materials Science, Universität
Bremen, Bremen 28359, Germany
- Beijing
Computational Science Research Center, Beijing 100193, China
- Shenzhen
JL Computational Science and Applied Research Institute, Shenzhen 518109, China
| | - Ritabrata Sarkar
- Department
of Chemistry, University of Gour Banga, Malda 732103, India
- Bremen
Center
for Computational Materials Science, Universität
Bremen, Bremen 28359, Germany
| | - Sougata Pal
- Department
of Chemistry, University of Gour Banga, Malda 732103, India
| | - Oleg V. Prezhdo
- Department
of Chemistry, University of Southern California, Los Angeles, California 90089, United States
- Department
of Physics and Astronomy, University of
Southern California, Los Angeles, California 90089, United States
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2
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Han G, Chowdhury U, Eriten M, Henak CR. Relaxation capacity of cartilage is a critical factor in rate- and integrity-dependent fracture. Sci Rep 2021; 11:9527. [PMID: 33947908 PMCID: PMC8096812 DOI: 10.1038/s41598-021-88942-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [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: 01/12/2021] [Accepted: 04/15/2021] [Indexed: 11/30/2022] Open
Abstract
Articular cartilage heals poorly but experiences mechanically induced damage across a broad range of loading rates and matrix integrity. Because loading rates and matrix integrity affect cartilage mechanical responses due to poroviscoelastic relaxation mechanisms, their effects on cartilage failure are important for assessing and preventing failure. This paper investigated rate- and integrity-dependent crack nucleation in cartilage from pre- to post-relaxation timescales. Rate-dependent crack nucleation and relaxation responses were obtained as a function of matrix integrity through microindentation. Total work for crack nucleation increased with decreased matrix integrity, and with decreased loading rates. Critical energy release rate of intact cartilage was estimated as 2.39 ± 1.39 to 2.48 ± 1.26 kJ m-2 in a pre-relaxation timescale. These findings showed that crack nucleation is delayed when cartilage can accommodate localized loading through poroviscoelastic relaxation mechanisms before fracture at a given loading rate and integrity state.
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Affiliation(s)
- G Han
- Department of Mechanical Engineering, University of Minnesota, 111 Church St SE, Minneapolis, MN, 55455, USA
| | - U Chowdhury
- Department of Mechanical Engineering, University of Wisconsin-Madison, 1513 University Ave., Madison, WI, 53706, USA
| | - M Eriten
- Department of Mechanical Engineering, University of Wisconsin-Madison, 1513 University Ave., Madison, WI, 53706, USA
| | - C R Henak
- Department of Mechanical Engineering, University of Wisconsin-Madison, 1513 University Ave., Madison, WI, 53706, USA.
- Department of Biomedical Engineering, University of Wisconsin-Madison, 1550 University Ave., Madison, WI, 53706, USA.
- Department of Orthopedics and Rehabilitation, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI, 53705, USA.
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3
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Amole C, Ardid M, Arnquist I, Asner D, Baxter D, Behnke E, Bressler M, Broerman B, Cao G, Chen C, Chowdhury U, Clark K, Collar J, Cooper P, Coutu C, Cowles C, Crisler M, Crowder G, Cruz-Venegas N, Dahl C, Das M, Fallows S, Farine J, Felis I, Filgas R, Girard F, Giroux G, Hall J, Hardy C, Harris O, Hillier T, Hoppe E, Jackson C, Jin M, Klopfenstein L, Kozynets T, Krauss C, Laurin M, Lawson I, Leblanc A, Levine I, Licciardi C, Lippincott W, Loer B, Mamedov F, Mitra P, Moore C, Nania T, Neilson R, Noble A, Oedekerk P, Ortega A, Piro MC, Plante A, Podviyanuk R, Priya S, Robinson A, Sahoo S, Scallon O, Seth S, Sonnenschein A, Starinski N, Štekl I, Sullivan T, Tardif F, Vázquez-Jáuregui E, Walkowski N, Weima E, Wichoski U, Wierman K, Yan Y, Zacek V, Zhang J. Dark matter search results from the complete exposure of the PICO-60
C3F8
bubble chamber. Int J Clin Exp Med 2019. [DOI: 10.1103/physrevd.100.022001] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Abstract
Aims and Method
Young people attending the Maudsley obsessive–compulsive disorder (OCD) children's clinic had expressed an interest in meeting other similar young people with OCD. A group was set up comprising 6-weekly sessions focusing on psycho-education and support.
Results
Seven young people (mean age: 14 years 4 months; age range: 11 years 11 months to 16 years 6 months) took part. Feedback questionnaires showed that all the participants found the group helpful and enjoy-able. They felt less isolated and more confident about dealing with OCD.
Clinical Implications
Establishment of groups may be a valuable way of increasing awareness and knowledge on aspects of OCD, as well as providing much-needed psycho-social support to patients.
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5
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Amole C, Ardid M, Arnquist IJ, Asner DM, Baxter D, Behnke E, Bhattacharjee P, Borsodi H, Bou-Cabo M, Campion P, Cao G, Chen CJ, Chowdhury U, Clark K, Collar JI, Cooper PS, Crisler M, Crowder G, Dahl CE, Das M, Fallows S, Farine J, Felis I, Filgas R, Girard F, Giroux G, Hall J, Harris O, Hoppe EW, Jin M, Krauss CB, Laurin M, Lawson I, Leblanc A, Levine I, Lippincott WH, Mamedov F, Maurya D, Mitra P, Nania T, Neilson R, Noble AJ, Olson S, Ortega A, Plante A, Podviyanuk R, Priya S, Robinson AE, Roeder A, Rucinski R, Scallon O, Seth S, Sonnenschein A, Starinski N, Štekl I, Tardif F, Vázquez-Jáuregui E, Wells J, Wichoski U, Yan Y, Zacek V, Zhang J. Dark Matter Search Results from the PICO-60 C_{3}F_{8} Bubble Chamber. Phys Rev Lett 2017; 118:251301. [PMID: 28696731 DOI: 10.1103/physrevlett.118.251301] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Indexed: 06/07/2023]
Abstract
New results are reported from the operation of the PICO-60 dark matter detector, a bubble chamber filled with 52 kg of C_{3}F_{8} located in the SNOLAB underground laboratory. As in previous PICO bubble chambers, PICO-60 C_{3}F_{8} exhibits excellent electron recoil and alpha decay rejection, and the observed multiple-scattering neutron rate indicates a single-scatter neutron background of less than one event per month. A blind analysis of an efficiency-corrected 1167-kg day exposure at a 3.3-keV thermodynamic threshold reveals no single-scattering nuclear recoil candidates, consistent with the predicted background. These results set the most stringent direct-detection constraint to date on the weakly interacting massive particle (WIMP)-proton spin-dependent cross section at 3.4×10^{-41} cm^{2} for a 30-GeV c^{-2} WIMP, more than 1 order of magnitude improvement from previous PICO results.
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Affiliation(s)
- C Amole
- Department of Physics, Queen's University, Kingston K7L 3N6, Canada
| | - M Ardid
- Departament de Física Aplicada, IGIC-Universitat Politècnica de València, Gandia 46730 Spain
| | - I J Arnquist
- Pacific Northwest National Laboratory, Richland, Washington 99354, USA
| | - D M Asner
- Pacific Northwest National Laboratory, Richland, Washington 99354, USA
| | - D Baxter
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - E Behnke
- Department of Physics, Indiana University South Bend, South Bend, Indiana 46634, USA
| | - P Bhattacharjee
- Astroparticle Physics and Cosmology Division, Saha Institute of Nuclear Physics, Kolkata 700064, India
| | - H Borsodi
- Department of Physics, Indiana University South Bend, South Bend, Indiana 46634, USA
| | - M Bou-Cabo
- Departament de Física Aplicada, IGIC-Universitat Politècnica de València, Gandia 46730 Spain
| | - P Campion
- Department of Physics, Drexel University, Philadelphia, Pennsylvania 19104, USA
| | - G Cao
- Department of Physics, Queen's University, Kingston K7L 3N6, Canada
| | - C J Chen
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA
| | - U Chowdhury
- Department of Physics, Queen's University, Kingston K7L 3N6, Canada
| | - K Clark
- Department of Physics, Laurentian University, Sudbury P3E 2C6, Canada
- SNOLAB, Lively, Ontario P3Y 1N2, Canada
| | - J I Collar
- Enrico Fermi Institute, KICP and Department of Physics, University of Chicago, Chicago, Illinois 60637, USA
| | - P S Cooper
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - M Crisler
- Pacific Northwest National Laboratory, Richland, Washington 99354, USA
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - G Crowder
- Department of Physics, Queen's University, Kingston K7L 3N6, Canada
| | - C E Dahl
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - M Das
- Astroparticle Physics and Cosmology Division, Saha Institute of Nuclear Physics, Kolkata 700064, India
| | - S Fallows
- Department of Physics, University of Alberta, Edmonton T6G 2E1, Canada
| | - J Farine
- Department of Physics, Laurentian University, Sudbury P3E 2C6, Canada
| | - I Felis
- Departament de Física Aplicada, IGIC-Universitat Politècnica de València, Gandia 46730 Spain
| | - R Filgas
- Institute of Experimental and Applied Physics, Czech Technical University in Prague, Prague, Cz-12800, Czech Republic
| | - F Girard
- Department of Physics, Laurentian University, Sudbury P3E 2C6, Canada
- Département de Physique, Université de Montréal, Montréal H3C 3J7, Canada
| | - G Giroux
- Department of Physics, Queen's University, Kingston K7L 3N6, Canada
| | - J Hall
- Pacific Northwest National Laboratory, Richland, Washington 99354, USA
| | - O Harris
- Department of Physics, Indiana University South Bend, South Bend, Indiana 46634, USA
- Northeastern Illinois University, Chicago, Illinois 60625, USA
| | - E W Hoppe
- Pacific Northwest National Laboratory, Richland, Washington 99354, USA
| | - M Jin
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA
| | - C B Krauss
- Department of Physics, University of Alberta, Edmonton T6G 2E1, Canada
| | - M Laurin
- Département de Physique, Université de Montréal, Montréal H3C 3J7, Canada
| | - I Lawson
- Department of Physics, Laurentian University, Sudbury P3E 2C6, Canada
- SNOLAB, Lively, Ontario P3Y 1N2, Canada
| | - A Leblanc
- Department of Physics, Laurentian University, Sudbury P3E 2C6, Canada
| | - I Levine
- Department of Physics, Indiana University South Bend, South Bend, Indiana 46634, USA
| | - W H Lippincott
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - F Mamedov
- Institute of Experimental and Applied Physics, Czech Technical University in Prague, Prague, Cz-12800, Czech Republic
| | - D Maurya
- Bio-Inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Material and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061, USA
| | - P Mitra
- Department of Physics, University of Alberta, Edmonton T6G 2E1, Canada
| | - T Nania
- Department of Physics, Indiana University South Bend, South Bend, Indiana 46634, USA
| | - R Neilson
- Department of Physics, Drexel University, Philadelphia, Pennsylvania 19104, USA
| | - A J Noble
- Department of Physics, Queen's University, Kingston K7L 3N6, Canada
| | - S Olson
- Department of Physics, Queen's University, Kingston K7L 3N6, Canada
| | - A Ortega
- Enrico Fermi Institute, KICP and Department of Physics, University of Chicago, Chicago, Illinois 60637, USA
| | - A Plante
- Département de Physique, Université de Montréal, Montréal H3C 3J7, Canada
| | - R Podviyanuk
- Department of Physics, Laurentian University, Sudbury P3E 2C6, Canada
| | - S Priya
- Bio-Inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Material and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061, USA
| | - A E Robinson
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - A Roeder
- Department of Physics, Indiana University South Bend, South Bend, Indiana 46634, USA
| | - R Rucinski
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - O Scallon
- Department of Physics, Laurentian University, Sudbury P3E 2C6, Canada
| | - S Seth
- Astroparticle Physics and Cosmology Division, Saha Institute of Nuclear Physics, Kolkata 700064, India
| | - A Sonnenschein
- Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA
| | - N Starinski
- Département de Physique, Université de Montréal, Montréal H3C 3J7, Canada
| | - I Štekl
- Institute of Experimental and Applied Physics, Czech Technical University in Prague, Prague, Cz-12800, Czech Republic
| | - F Tardif
- Département de Physique, Université de Montréal, Montréal H3C 3J7, Canada
| | - E Vázquez-Jáuregui
- Department of Physics, Laurentian University, Sudbury P3E 2C6, Canada
- Instituto de Física, Universidad Nacional Autónoma de México, México D. F. 01000, Mexico
| | - J Wells
- Department of Physics, Indiana University South Bend, South Bend, Indiana 46634, USA
| | - U Wichoski
- Department of Physics, Laurentian University, Sudbury P3E 2C6, Canada
| | - Y Yan
- Bio-Inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Material and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061, USA
| | - V Zacek
- Département de Physique, Université de Montréal, Montréal H3C 3J7, Canada
| | - J Zhang
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA
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6
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Takon I, Rickards H, Chowdhury U, Sharma S. ‘I GET THIS FEELING LIKE GRAPES BUBBLING THROUGH AND I TRY HARD TO PRESS THEM IN’. A QUALITATIVE STUDY OF PREMONITORY URGES IN CHILDREN WITH TIC DISORDERS. J Neurol Neurosurg Psychiatry 2015. [DOI: 10.1136/jnnp-2015-311750.38] [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: 11/03/2022]
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7
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Lennarz A, Grossheim A, Leach KG, Alanssari M, Brunner T, Chaudhuri A, Chowdhury U, Crespo López-Urrutia JR, Gallant AT, Holl M, Kwiatkowski AA, Lassen J, Macdonald TD, Schultz BE, Seeraji S, Simon MC, Andreoiu C, Dilling J, Frekers D. In-trap spectroscopy of charge-bred radioactive ions. Phys Rev Lett 2014; 113:082502. [PMID: 25192092 DOI: 10.1103/physrevlett.113.082502] [Citation(s) in RCA: 3] [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: 04/04/2014] [Indexed: 06/03/2023]
Abstract
In this Letter, we introduce the concept of in-trap nuclear decay spectroscopy of highly charged radioactive ions and describe its successful application as a novel spectroscopic tool. This is demonstrated by a measurement of the decay properties of radioactive mass A=124 ions (here, ^{124}In and ^{124}Cs) in the electron-beam ion trap of the TITAN facility at TRIUMF. By subjecting the trapped ions to an intense electron beam, the ions are charge bred to high charge states (i.e., equivalent to the removal of N-shell electrons), and an increase of storage times to the level of minutes without significant ion losses is achieved. The present technique opens the venue for precision spectroscopy of low branching ratios and is being developed in the context of measuring electron-capture branching ratios needed for determining the nuclear ground-state properties of the intermediate odd-odd nuclei in double-beta (ββ) decay.
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Affiliation(s)
- A Lennarz
- Institut für Kernphysik, Westfälische Wilhelms-Universität, 48149 Münster, Germany and TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - A Grossheim
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada and Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - K G Leach
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada and Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - M Alanssari
- Institut für Kernphysik, Westfälische Wilhelms-Universität, 48149 Münster, Germany
| | - T Brunner
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - A Chaudhuri
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - U Chowdhury
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada and Department of Physics, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | | | - A T Gallant
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada and Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - M Holl
- Institut für Kernphysik, Westfälische Wilhelms-Universität, 48149 Münster, Germany
| | | | - J Lassen
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - T D Macdonald
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada and Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - B E Schultz
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - S Seeraji
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - M C Simon
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - C Andreoiu
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - J Dilling
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada and Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - D Frekers
- Institut für Kernphysik, Westfälische Wilhelms-Universität, 48149 Münster, Germany
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Gallant AT, Brodeur M, Andreoiu C, Bader A, Chaudhuri A, Chowdhury U, Grossheim A, Klawitter R, Kwiatkowski AA, Leach KG, Lennarz A, Macdonald TD, Schultz BE, Lassen J, Heggen H, Raeder S, Teigelhöfer A, Brown BA, Magilligan A, Holt JD, Menéndez J, Simonis J, Schwenk A, Dilling J. Breakdown of the isobaric multiplet mass equation for the A = 20 and 21 multiplets. Phys Rev Lett 2014; 113:082501. [PMID: 25192091 DOI: 10.1103/physrevlett.113.082501] [Citation(s) in RCA: 2] [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: 11/27/2013] [Indexed: 06/03/2023]
Abstract
Using the Penning trap mass spectrometer TITAN, we performed the first direct mass measurements of (20,21)Mg, isotopes that are the most proton-rich members of the A = 20 and A = 21 isospin multiplets. These measurements were possible through the use of a unique ion-guide laser ion source, a development that suppressed isobaric contamination by 6 orders of magnitude. Compared to the latest atomic mass evaluation, we find that the mass of (21)Mg is in good agreement but that the mass of (20)Mg deviates by 3 σ. These measurements reduce the uncertainties in the masses of (20,21)Mg by 15 and 22 times, respectively, resulting in a significant departure from the expected behavior of the isobaric multiplet mass equation in both the A = 20 and A = 21 multiplets. This presents a challenge to shell model calculations using either the isospin nonconserving universal sd USDA and USDB Hamiltonians or isospin nonconserving interactions based on chiral two- and three-nucleon forces.
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Affiliation(s)
- A T Gallant
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada and Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, V6T 1Z1 Canada
| | - M Brodeur
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - C Andreoiu
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6 Canada
| | - A Bader
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada and École des Mines de Nantes, La Chantrerie, 4, rue Alfred Kastler, B.P. 20722, F-44307 Nantes Cedex 3, France
| | - A Chaudhuri
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada
| | - U Chowdhury
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada and Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, R3T 2N2 Canada
| | - A Grossheim
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada
| | - R Klawitter
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada and Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
| | - A A Kwiatkowski
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada
| | - K G Leach
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada and Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6 Canada
| | - A Lennarz
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada and Institut für Kernphysik, Westfälische Wilhelms-Universität, D-48149 Münster, Germany
| | - T D Macdonald
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada and Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, V6T 1Z1 Canada
| | - B E Schultz
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada
| | - J Lassen
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada and Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, R3T 2N2 Canada
| | - H Heggen
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada
| | - S Raeder
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada
| | - A Teigelhöfer
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada and Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, R3T 2N2 Canada
| | - B A Brown
- Department of Physics and Astronomy and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321, USA
| | - A Magilligan
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - J D Holt
- Department of Physics and Astronomy and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321, USA and Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - J Menéndez
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - J Simonis
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - A Schwenk
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - J Dilling
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada and Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, V6T 1Z1 Canada
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9
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Chaudhuri A, Andreoiu C, Brunner T, Chowdhury U, Ettenauer S, Frekers D, Gallant A, Grossheim A, Gwinner G, Klawitter R, Kwiatkowski A, Leach K, Lennarz A, Lunney D, Macdonald TD, Schultz B, Seeraji S, Simon M, Simon V, Dilling AJ. Precision mass measurements of short-lived nuclides for nuclear structure studies at TITAN. EPJ Web of Conferences 2014. [DOI: 10.1051/epjconf/20146602030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Gallant AT, Bale JC, Brunner T, Chowdhury U, Ettenauer S, Lennarz A, Robertson D, Simon VV, Chaudhuri A, Holt JD, Kwiatkowski AA, Mané E, Menéndez J, Schultz BE, Simon MC, Andreoiu C, Delheij P, Pearson MR, Savajols H, Schwenk A, Dilling J. New precision mass measurements of neutron-rich calcium and potassium isotopes and three-nucleon forces. Phys Rev Lett 2012; 109:032506. [PMID: 22861844 DOI: 10.1103/physrevlett.109.032506] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 06/03/2012] [Indexed: 06/01/2023]
Abstract
We present precision Penning trap mass measurements of neutron-rich calcium and potassium isotopes in the vicinity of neutron number N=32. Using the TITAN system, the mass of 51K was measured for the first time, and the precision of the (51,52)Ca mass values were improved significantly. The new mass values show a dramatic increase of the binding energy compared to those reported in the atomic mass evaluation. In particular, 52Ca is more bound by 1.74 MeV, and the behavior with neutron number deviates substantially from the tabulated values. An increased binding was predicted recently based on calculations that include three-nucleon (3N) forces. We present a comparison to improved calculations, which agree remarkably with the evolution of masses with neutron number, making neutron-rich calcium isotopes an exciting region to probe 3N forces.
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Affiliation(s)
- A T Gallant
- TRIUMF, University of British Columbia, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.
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Simon MC, Bale JC, Chowdhury U, Eberhardt B, Ettenauer S, Gallant AT, Jang F, Lennarz A, Luichtl M, Ma T, Robertson D, Simon VV, Andreoiu C, Brodeur M, Brunner T, Chaudhuri A, Crespo López-Urrutia JR, Delheij P, Frekers D, Grossheim A, Gwinner G, Kwiatkowski AA, Lapierre A, Mané E, Pearson MR, Ringle R, Schultz BE, Dilling J. The on-line charge breeding program at TRIUMF's Ion Trap For Atomic and Nuclear Science for precision mass measurements. Rev Sci Instrum 2012; 83:02A912. [PMID: 22380253 DOI: 10.1063/1.3673505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN) constitutes the only high precision mass measurement setup coupled to a rare isotope facility capable of increasing the charge state of short-lived nuclides prior to the actual mass determination in a Penning trap. Recent developments around TITAN's charge breeder, the electron beam ion trap, form the basis for several successful experiments on radioactive isotopes with half-lives as low as 65 ms and in charge states as high as 22+.
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Affiliation(s)
- M C Simon
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada.
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Ettenauer S, Simon MC, Gallant AT, Brunner T, Chowdhury U, Simon VV, Brodeur M, Chaudhuri A, Mané E, Andreoiu C, Audi G, López-Urrutia JRC, Delheij P, Gwinner G, Lapierre A, Lunney D, Pearson MR, Ringle R, Ullrich J, Dilling J. First use of high charge states for mass measurements of short-lived nuclides in a Penning trap. Phys Rev Lett 2011; 107:272501. [PMID: 22243307 DOI: 10.1103/physrevlett.107.272501] [Citation(s) in RCA: 4] [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: 09/11/2011] [Indexed: 05/31/2023]
Abstract
Penning trap mass measurements of short-lived nuclides have been performed for the first time with highly charged ions, using the TITAN facility at TRIUMF. Compared to singly charged ions, this provides an improvement in experimental precision that scales with the charge state q. Neutron-deficient Rb isotopes have been charge bred in an electron beam ion trap to q=8-12+ prior to injection into the Penning trap. In combination with the Ramsey excitation scheme, this unique setup creating low energy, highly charged ions at a radioactive beam facility opens the door to unrivaled precision with gains of 1-2 orders of magnitude. The method is particularly suited for short-lived nuclides such as the superallowed β emitter 74Rb (T(1/2)=65 ms). The determination of its atomic mass and an improved Q(EC) value are presented.
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Affiliation(s)
- S Ettenauer
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada.
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Wong M, Chowdhury U, Collins C, Yang B, Denyszyn J, Kim K, Campbell J, Dupuis R. High Quantum Efficiency AlGaN/GaN Solar-Blind Photodetectors Grown by Metalorganic Chemical Vapor Deposition. ACTA ACUST UNITED AC 2001. [DOI: 10.1002/1521-396x(200111)188:1<333::aid-pssa333>3.0.co;2-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Lamarre P, Hairston A, Tobin S, Wong K, Sood A, Reine M, Pophristic M, Birkham R, Ferguson I, Singh R, Eddy C, Chowdhury U, Wong M, Dupuis R, Kozodoy P, Tarsa E. AlGaN UV Focal Plane Arrays. ACTA ACUST UNITED AC 2001. [DOI: 10.1002/1521-396x(200111)188:1<289::aid-pssa289>3.0.co;2-u] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
Imaging studies have greatly improved the understanding of the pathology and physiology of psychiatric disorders, such as schizophrenia, affective disorders, obsessive-compulsive disorder, and Tourette syndrome. In the past few years, several neuroimaging studies have concentrated on patients with eating disorders. Although the number of studies is small compared with studies of other psychiatric disorders, the results are beginning to highlight potential areas in the brain that may lead to a better understanding of these disorders. Much research still is needed, and replication of results across centers is needed. The brain is an extremely complex organ; that eating disorders are a result of abnormalities in one specific area of the brain is unlikely. More likely is that several components of the brain have a role, including cortex and subcortical regions and involvement of several neurochemical pathways and circuits within the brain. Further studies are needed in this exciting development of research about eating disorders.
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Affiliation(s)
- U Chowdhury
- Department of Psychological Medicine, Great Ormond Street Hospital for Children, London, United Kingdom.
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Blaveri E, Kalsi G, Lawrence J, Quested D, Moorey H, Lamb G, Kohen D, Shiwach R, Chowdhury U, Curtis D, McQuillin A, Gramoustianou ES, Gurling HM. Genetic association studies of schizophrenia using the 8p21-22 genes: prepronociceptin (PNOC), neuronal nicotinic cholinergic receptor alpha polypeptide 2 (CHRNA2) and arylamine N-acetyltransferase 1 (NAT1). Eur J Hum Genet 2001; 9:469-72. [PMID: 11436130 DOI: 10.1038/sj.ejhg.5200646] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2000] [Revised: 02/19/2001] [Accepted: 02/23/2001] [Indexed: 11/09/2022] Open
Abstract
Schizophrenia is a common, genetically heterogeneous disorder with a lifetime prevalence of approximately 1% in the general population. Linkage studies of affected families have now strongly implicated a susceptibility locus on chromosome 8p21-22. Tests of allelic association with markers on 8p21-22 should be able to localise any quantitative trait nucleotides (QTN's) or susceptibility mutations to within a few hundred kilobases. Three brain expressed candidate susceptibility genes, prepronociceptin (PNOC), neuronal cholinergic receptor, nicotinic, alpha polypeptide 2 (CHRNA2) and arylamine N-acetyltransferase 1 (NAT1) have been mapped to chromosome 8p21-22. A case-control, allelic association study was performed using a novel highly polymorphic dinucleotide repeat, D8S2611 near the PNOC gene, two previously characterised dinucleotide repeats, D8S131 and D8S131P at the CHRNA2 locus and an RFLP at the 3'UTR of the arylamine N-acetyltransferase 1 (NAT1) gene. No differences were found in allele frequencies between the patient and control groups. DNA variations or mutations at or near the three genes under study are unlikely to increase susceptibility to schizophrenia in our population sample.
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Affiliation(s)
- E Blaveri
- Molecular Psychiatry Laboratory, Windeyer Institute of Medical Sciences, Department of Psychiatry and Behavioural Sciences, Royal Free and University College London Medical School, Windeyer Building, 46 Cleveland Street, London W1P 6DB, UK
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Kanno N, Glaser S, Chowdhury U, Phinizy JL, Baiocchi L, Francis H, LeSage G, Alpini G. Gastrin inhibits cholangiocarcinoma growth through increased apoptosis by activation of Ca2+-dependent protein kinase C-alpha. J Hepatol 2001; 34:284-91. [PMID: 11281558 DOI: 10.1016/s0168-8278(00)00025-8] [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] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND/AIMS We determined the role of gastrin in the regulation of cholangiocarcinoma growth. METHODS We evaluated for the functional presence of cholecystokinin (CCK)-B/gastrin receptors in the cholangiocarcinoma cell lines, Mz-ChA-1, HuH-28 and TFK-1. We determined the effect of gastrin on the growth of Mz-ChA-1, HuH-28 and TFK-1 cells. We evaluated the effect of gastrin on growth and apoptosis of Mz-ChA-1 in the absence or presence of inhibitors for CCK-A (L-364, 718) and CCK-B/gastrin (L-365, 260) receptors, the intracellular Ca2+ chelator (BAPTA/AM), and the protein kinase C (PKC)-alpha inhibitor, H7. We evaluated if gastrin effects on Mz-ChA-1 growth and apoptosis are associated with membrane translocation of PKC-alpha. RESULTS Gastrin inhibited DNA synthesis of Mz-ChA-1, HuH-28 and TFK-1 cells in a dose- and time-dependent fashion. The antiproliferative effect of gastrin on Mz-ChA-1 cells was inhibited by L-365, 260, H7 and BAPTA/AM but not L-364, 718. Gastrin induced membrane translocation of PKC-alpha. The inhibition of growth of Mz-ChA-1 cells by gastrin was associated with increased apoptosis through a PKC-dependent mechanism. CONCLUSIONS Gastrin inhibits the growth of Mz-ChA-1, HuH-28 and TFK-1 cells. Gastrin inhibits growth and induces apoptosis in Mz-ChA-1 cells through the Ca2+-dependent PKC-alpha. The data suggest a therapeutic role for gastrin in the modulation of cholangiocarcinoma growth.
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Affiliation(s)
- N Kanno
- Medical Physiology, The Texas A&M University System Health Science Center, College of Medicine, Temple 76504, USA
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Joos TO, Schrenk M, Höpfl P, Kröger K, Chowdhury U, Stoll D, Schörner D, Dürr M, Herick K, Rupp S, Sohn K, Hämmerle H. A microarray enzyme-linked immunosorbent assay for autoimmune diagnostics. Electrophoresis 2000; 21:2641-50. [PMID: 10949141 DOI: 10.1002/1522-2683(20000701)21:13<2641::aid-elps2641>3.0.co;2-5] [Citation(s) in RCA: 216] [Impact Index Per Article: 9.0] [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: 01/30/2023]
Abstract
In order to quantify autoantibodies in the sera of patients with autoimmune disease, we have created a microarray-based immunoassay that allows the simultaneous analysis of 18 known autoantigens. The microarrays contain serial dilutions of the various antigens, thereby allowing accurate determination of autoantibody titer using minimal amounts of serum. The assay is very sensitive and highly specific: as little as 40 fg of a known protein standard can be detected with little or no cross-reactivity to nonspecific proteins. The signal intensities observed from serial dilutions of immobilized antigen correlate well with serial dilutions of autoimmune sera. Miniaturized and highly parallelized immunoassays like these will reduce costs by decreasing reagent consumption and improve efficiency by greatly increasing the number of assays that can be performed with a single serum sample. This system will significantly facilitate and accelerate the diagnostics of autoimmune diseases and can be adapted easily to any other kind of immunoassay.
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Affiliation(s)
- T O Joos
- NMI Natural and Medical Sciences Institute at the University of Tuebingen, Reutlingen, Germany.
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Pandit S, Biswas TK, Debnath PK, Saha AV, Chowdhury U, Shaw BP, Sen S, Mukherjee B. Chemical and pharmacological evaluation of different ayurvedic preparations of iron. J Ethnopharmacol 1999; 65:149-156. [PMID: 10465655 DOI: 10.1016/s0378-8741(99)00003-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Ayurvedic preparations of metallic iron commonly categorised as different 'putas' of 'Louha Bhasma' was chemically analysed and pharmacologically investigated in iron deficiency anemia. Atomic absorption spectral (AAS) study of different putas of Louha Bhasma revealed the presence of various proportions of important metals along with varied concentration of iron in it. The effect of a representative puta viz. 50 puta of Louha Bhasma in the management of agar gel diet and phlebotomy induced iron deficiency anemia in animal model was found to be statistically highly significant (P < 0.001) in comparison to the control and standard drug Fefol treated groups.
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Affiliation(s)
- S Pandit
- Department of Kayachikitsa, Inst. of Post-graduate Ayurvedic Education & Research, Calcutta, India
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Das T, Mukherjee S, Chowdhury U. A case of non-Hodgkin's lymphoma with bone involvement. J Indian Med Assoc 1996; 94:152-153. [PMID: 8854635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- T Das
- Medical College, Calcutta
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John S, Ravikumar E, Jairaj PS, Chowdhury U, Krishnaswami S. Valve replacement in the young patient with rheumatic heart disease. Review of a twenty-year experience. J Thorac Cardiovasc Surg 1990; 99:631-8. [PMID: 2319783] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
During a 20-year period 303 young subjects between 9 and 20 years of age (mean, 16.2 +/- 2.72 years) with rapid and relentlessly progressive valvular disease from rheumatic fever underwent valve replacements. The Starr-Edwards ball valve prosthesis remains the device of choice, although other valves have been implanted. The overall hospital mortality rate was 9.6% in the mitral valve, 3.5% in the aortic valve, and 4.2% in the double valve replacement groups. Actuarial survival at 10, 15, and 20 years was 78.4% (+/- 3.3%), 70.0% (+/- 5.8%), and 59.3% (+/- 11.1%), respectively, for patients with mitral valve replacement. The rates for aortic valve replacement were 85.9% (+/- 4.6%) at 10 and 15 years and 72.7% (12.8%) at 20 years. In the double valve replacement group the survival rates after 5 and 10 years were 79.9% (+/- 5.1%). The incidence of thromboembolism was 0.41, 0.59, and 1.04 per 100 patient-years for the mitral, aortic, and double-valve prostheses, respectively. The prospect of childbearing seems promising in those young women who were subsequently married. Our favorable and gratifying experience in this review bears testimony to the physiologic advantages of the Starr-Edwards valve as the device of choice in the rehabilitation of patients with advanced and severe valvular disease after rheumatic fever.
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Affiliation(s)
- S John
- Department of Thoracic and Cardiovascular Surgery, Christian Medical College Hospital, Vellore, India
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