1
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Tzschaschel C, Qiu JX, Gao XJ, Li HC, Guo C, Yang HY, Zhang CP, Xie YM, Liu YF, Gao A, Bérubé D, Dinh T, Ho SC, Fang Y, Huang F, Nordlander J, Ma Q, Tafti F, Moll PJW, Law KT, Xu SY. Nonlinear optical diode effect in a magnetic Weyl semimetal. Nat Commun 2024; 15:3017. [PMID: 38589414 DOI: 10.1038/s41467-024-47291-8] [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: 07/19/2023] [Accepted: 03/27/2024] [Indexed: 04/10/2024] Open
Abstract
Diode effects are of great interest for both fundamental physics and modern technologies. Electrical diode effects (nonreciprocal transport) have been observed in Weyl systems. Optical diode effects arising from the Weyl fermions have been theoretically considered but not probed experimentally. Here, we report the observation of a nonlinear optical diode effect (NODE) in the magnetic Weyl semimetal CeAlSi, where the magnetization introduces a pronounced directionality in the nonlinear optical second-harmonic generation (SHG). We demonstrate a six-fold change of the measured SHG intensity between opposite propagation directions over a bandwidth exceeding 250 meV. Supported by density-functional theory, we establish the linearly dispersive bands emerging from Weyl nodes as the origin of this broadband effect. We further demonstrate current-induced magnetization switching and thus electrical control of the NODE. Our results advance ongoing research to identify novel nonlinear optical/transport phenomena in magnetic topological materials and further opens new pathways for the unidirectional manipulation of light.
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Affiliation(s)
- Christian Tzschaschel
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA.
- Max-Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, Berlin, Germany.
| | - Jian-Xiang Qiu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Xue-Jian Gao
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Hou-Chen Li
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Chunyu Guo
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
- Laboratory of Quantum Materials (QMAT), Institute of Materials (IMX), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Hung-Yu Yang
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Cheng-Ping Zhang
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Ying-Ming Xie
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Yu-Fei Liu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Anyuan Gao
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Damien Bérubé
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Thao Dinh
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Sheng-Chin Ho
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Yuqiang Fang
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai, China
- State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering Peking University, Beijing, China
| | - Fuqiang Huang
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai, China
- State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering Peking University, Beijing, China
| | | | - Qiong Ma
- Department of Physics, Boston College, Chestnut Hill, MA, USA
- CIFAR Azrieli Global Scholars program, CIFAR, Toronto, Ontario, Canada
| | - Fazel Tafti
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Philip J W Moll
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
- Laboratory of Quantum Materials (QMAT), Institute of Materials (IMX), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Kam Tuen Law
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Su-Yang Xu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA.
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2
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Gao A, Liu YF, Qiu JX, Ghosh B, V Trevisan T, Onishi Y, Hu C, Qian T, Tien HJ, Chen SW, Huang M, Bérubé D, Li H, Tzschaschel C, Dinh T, Sun Z, Ho SC, Lien SW, Singh B, Watanabe K, Taniguchi T, Bell DC, Lin H, Chang TR, Du CR, Bansil A, Fu L, Ni N, Orth PP, Ma Q, Xu SY. Quantum metric nonlinear Hall effect in a topological antiferromagnetic heterostructure. Science 2023:eadf1506. [PMID: 37319246 DOI: 10.1126/science.adf1506] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 06/06/2023] [Indexed: 06/17/2023]
Abstract
Quantum geometry in condensed matter physics has two components: the real part quantum metric and the imaginary part Berry curvature. Whereas the effects of Berry curvature have been observed through phenomena such as the quantum Hall effect in 2D electron gases and the anomalous Hall effect (AHE) in ferromagnets, quantum metric has rarely been explored. Here, we report a nonlinear Hall effect induced by quantum metric dipole by interfacing even-layered MnBi2Te4 with black phosphorus. The quantum metric nonlinear Hall effect switches direction upon reversing the AFM spins and exhibits distinct scaling that is independent of the scattering time. Our results open the door to discovering quantum metric responses predicted theoretically and pave the way for applications that bridge nonlinear electronics with AFM spintronics.
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Affiliation(s)
- Anyuan Gao
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Yu-Fei Liu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Jian-Xiang Qiu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Barun Ghosh
- Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Thaís V Trevisan
- Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA
- Ames National Laboratory, Ames, IA 50011, USA
| | - Yugo Onishi
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Chaowei Hu
- Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Tiema Qian
- Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Hung-Ju Tien
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - Shao-Wen Chen
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Mengqi Huang
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
| | - Damien Bérubé
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Houchen Li
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Christian Tzschaschel
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Thao Dinh
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
- Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Zhe Sun
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Sheng-Chin Ho
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Shang-Wei Lien
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - Bahadur Singh
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Colaba, Mumbai, India
| | - Kenji Watanabe
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - David C Bell
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
- Center for Nanoscale Systems, Harvard University, Cambridge, MA 02138, USA
| | - Hsin Lin
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
| | - Tay-Rong Chang
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - Chunhui Rita Du
- Department of Physics, University of California San Diego, La Jolla, CA 92093, USA
| | - Arun Bansil
- Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Liang Fu
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Ni Ni
- Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Peter P Orth
- Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA
- Ames National Laboratory, Ames, IA 50011, USA
| | - Qiong Ma
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Su-Yang Xu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
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3
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Qiu JX, Tzschaschel C, Ahn J, Gao A, Li H, Zhang XY, Ghosh B, Hu C, Wang YX, Liu YF, Bérubé D, Dinh T, Gong Z, Lien SW, Ho SC, Singh B, Watanabe K, Taniguchi T, Bell DC, Lu HZ, Bansil A, Lin H, Chang TR, Zhou BB, Ma Q, Vishwanath A, Ni N, Xu SY. Axion optical induction of antiferromagnetic order. Nat Mater 2023; 22:583-590. [PMID: 36894774 DOI: 10.1038/s41563-023-01493-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 01/25/2023] [Indexed: 05/05/2023]
Abstract
Using circularly polarized light to control quantum matter is a highly intriguing topic in physics, chemistry and biology. Previous studies have demonstrated helicity-dependent optical control of chirality and magnetization, with important implications in asymmetric synthesis in chemistry; homochirality in biomolecules; and ferromagnetic spintronics. We report the surprising observation of helicity-dependent optical control of fully compensated antiferromagnetic order in two-dimensional even-layered MnBi2Te4, a topological axion insulator with neither chirality nor magnetization. To understand this control, we study an antiferromagnetic circular dichroism, which appears only in reflection but is absent in transmission. We show that the optical control and circular dichroism both arise from the optical axion electrodynamics. Our axion induction provides the possibility to optically control a family of [Formula: see text]-symmetric antiferromagnets ([Formula: see text], inversion; [Formula: see text], time-reversal) such as Cr2O3, even-layered CrI3 and possibly the pseudo-gap state in cuprates. In MnBi2Te4, this further opens the door for optical writing of a dissipationless circuit formed by topological edge states.
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Affiliation(s)
- Jian-Xiang Qiu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Christian Tzschaschel
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Junyeong Ahn
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Anyuan Gao
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Houchen Li
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Xin-Yue Zhang
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Barun Ghosh
- Department of Physics, Northeastern University, Boston, MA, USA
| | - Chaowei Hu
- Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, CA, USA
| | - Yu-Xuan Wang
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Yu-Fei Liu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Damien Bérubé
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Thao Dinh
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Zhenhao Gong
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen, China
- Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (Guangdong), Shenzhen, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen, China
- International Quantum Academy, Shenzhen, China
| | - Shang-Wei Lien
- Department of Physics, National Cheng Kung University, Tainan, Taiwan
- Center for Quantum Frontiers of Research and Technology (QFort), Tainan, Taiwan
- Physics Division, National Center for Theoretical Sciences, Taipei, Taiwan
| | - Sheng-Chin Ho
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Bahadur Singh
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai, India
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - David C Bell
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
- Center for Nanoscale Systems, Harvard University, Cambridge, MA, USA
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen, China
- Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (Guangdong), Shenzhen, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen, China
- International Quantum Academy, Shenzhen, China
| | - Arun Bansil
- Department of Physics, Northeastern University, Boston, MA, USA
| | - Hsin Lin
- Institute of Physics, Academia Sinica, Taipei, Taiwan
| | - Tay-Rong Chang
- Department of Physics, National Cheng Kung University, Tainan, Taiwan
- Center for Quantum Frontiers of Research and Technology (QFort), Tainan, Taiwan
- Physics Division, National Center for Theoretical Sciences, Taipei, Taiwan
| | - Brian B Zhou
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Qiong Ma
- Department of Physics, Boston College, Chestnut Hill, MA, USA
- Canadian Institute for Advanced Research, Toronto, Canada
| | | | - Ni Ni
- Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, CA, USA.
| | - Su-Yang Xu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
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4
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Gao A, Liu YF, Hu C, Qiu JX, Tzschaschel C, Ghosh B, Ho SC, Bérubé D, Chen R, Sun H, Zhang Z, Zhang XY, Wang YX, Wang N, Huang Z, Felser C, Agarwal A, Ding T, Tien HJ, Akey A, Gardener J, Singh B, Watanabe K, Taniguchi T, Burch KS, Bell DC, Zhou BB, Gao W, Lu HZ, Bansil A, Lin H, Chang TR, Fu L, Ma Q, Ni N, Xu SY. Layer Hall effect in a 2D topological axion antiferromagnet. Nature 2021; 595:521-525. [PMID: 34290425 DOI: 10.1038/s41586-021-03679-w] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 05/27/2021] [Indexed: 11/10/2022]
Abstract
Whereas ferromagnets have been known and used for millennia, antiferromagnets were only discovered in the 1930s1. At large scale, because of the absence of global magnetization, antiferromagnets may seem to behave like any non-magnetic material. At the microscopic level, however, the opposite alignment of spins forms a rich internal structure. In topological antiferromagnets, this internal structure leads to the possibility that the property known as the Berry phase can acquire distinct spatial textures2,3. Here we study this possibility in an antiferromagnetic axion insulator-even-layered, two-dimensional MnBi2Te4-in which spatial degrees of freedom correspond to different layers. We observe a type of Hall effect-the layer Hall effect-in which electrons from the top and bottom layers spontaneously deflect in opposite directions. Specifically, under zero electric field, even-layered MnBi2Te4 shows no anomalous Hall effect. However, applying an electric field leads to the emergence of a large, layer-polarized anomalous Hall effect of about 0.5e2/h (where e is the electron charge and h is Planck's constant). This layer Hall effect uncovers an unusual layer-locked Berry curvature, which serves to characterize the axion insulator state. Moreover, we find that the layer-locked Berry curvature can be manipulated by the axion field formed from the dot product of the electric and magnetic field vectors. Our results offer new pathways to detect and manipulate the internal spatial structure of fully compensated topological antiferromagnets4-9. The layer-locked Berry curvature represents a first step towards spatial engineering of the Berry phase through effects such as layer-specific moiré potential.
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Affiliation(s)
- Anyuan Gao
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Yu-Fei Liu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Chaowei Hu
- Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA
| | - Jian-Xiang Qiu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Christian Tzschaschel
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Barun Ghosh
- Department of Physics, Indian Institute of Technology, Kanpur, India.,Department of Physics, Northeastern University, Boston, MA, USA
| | - Sheng-Chin Ho
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Damien Bérubé
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Rui Chen
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen, China
| | - Haipeng Sun
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen, China
| | - Zhaowei Zhang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Xin-Yue Zhang
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Yu-Xuan Wang
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Naizhou Wang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Zumeng Huang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, Dresden, Germany
| | - Amit Agarwal
- Department of Physics, Indian Institute of Technology, Kanpur, India
| | - Thomas Ding
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Hung-Ju Tien
- Department of Physics, National Cheng Kung University, Tainan, Taiwan
| | - Austin Akey
- Center for Nanoscale Systems, Harvard University, Cambridge, MA, USA
| | - Jules Gardener
- Center for Nanoscale Systems, Harvard University, Cambridge, MA, USA
| | - Bahadur Singh
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Mumbai, India
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - Kenneth S Burch
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - David C Bell
- Center for Nanoscale Systems, Harvard University, Cambridge, MA, USA.,Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Brian B Zhou
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Weibo Gao
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen, China
| | - Arun Bansil
- Department of Physics, Northeastern University, Boston, MA, USA
| | - Hsin Lin
- Institute of Physics, Academia Sinica, Taipei, Taiwan
| | - Tay-Rong Chang
- Department of Physics, National Cheng Kung University, Tainan, Taiwan.,Center for Quantum Frontiers of Research and Technology (QFort), Tainan, Taiwan.,Physics Division, National Center for Theoretical Sciences, National Taiwan University, Taipei, Taiwan
| | - Liang Fu
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Qiong Ma
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Ni Ni
- Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, USA.
| | - Su-Yang Xu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
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5
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Andersen TI, Scuri G, Sushko A, De Greve K, Sung J, Zhou Y, Wild DS, Gelly RJ, Heo H, Bérubé D, Joe AY, Jauregui LA, Watanabe K, Taniguchi T, Kim P, Park H, Lukin MD. Excitons in a reconstructed moiré potential in twisted WSe 2/WSe 2 homobilayers. Nat Mater 2021; 20:480-487. [PMID: 33398121 DOI: 10.1038/s41563-020-00873-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 11/11/2020] [Indexed: 06/12/2023]
Abstract
Moiré superlattices in twisted van der Waals materials have recently emerged as a promising platform for engineering electronic and optical properties. A major obstacle to fully understanding these systems and harnessing their potential is the limited ability to correlate direct imaging of the moiré structure with optical and electronic properties. Here we develop a secondary electron microscope technique to directly image stacking domains in fully functional van der Waals heterostructure devices. After demonstrating the imaging of AB/BA and ABA/ABC domains in multilayer graphene, we employ this technique to investigate reconstructed moiré patterns in twisted WSe2/WSe2 bilayers and directly correlate the increasing moiré periodicity with the emergence of two distinct exciton species in photoluminescence measurements. These states can be tuned individually through electrostatic gating and feature different valley coherence properties. We attribute our observations to the formation of an array of two intralayer exciton species that reside in alternating locations in the superlattice, and open up new avenues to realize tunable exciton arrays in twisted van der Waals heterostructures, with applications in quantum optoelectronics and explorations of novel many-body systems.
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Affiliation(s)
| | - Giovanni Scuri
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Andrey Sushko
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Kristiaan De Greve
- Department of Physics, Harvard University, Cambridge, MA, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- imec, Leuven, Belgium
| | - Jiho Sung
- Department of Physics, Harvard University, Cambridge, MA, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - You Zhou
- Department of Physics, Harvard University, Cambridge, MA, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Dominik S Wild
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Ryan J Gelly
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Hoseok Heo
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Damien Bérubé
- Department of Physics, California Institute of Technology, Pasadena, CA, USA
| | - Andrew Y Joe
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Luis A Jauregui
- Department of Physics, Harvard University, Cambridge, MA, USA
- Department of Physics and Astronomy, UC Irvine, Irvine, CA, USA
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - Philip Kim
- Department of Physics, Harvard University, Cambridge, MA, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Hongkun Park
- Department of Physics, Harvard University, Cambridge, MA, USA.
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
| | - Mikhail D Lukin
- Department of Physics, Harvard University, Cambridge, MA, USA.
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6
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Sung J, Zhou Y, Scuri G, Zólyomi V, Andersen TI, Yoo H, Wild DS, Joe AY, Gelly RJ, Heo H, Magorrian SJ, Bérubé D, Valdivia AMM, Taniguchi T, Watanabe K, Lukin MD, Kim P, Fal'ko VI, Park H. Broken mirror symmetry in excitonic response of reconstructed domains in twisted MoSe 2/MoSe 2 bilayers. Nat Nanotechnol 2020; 15:750-754. [PMID: 32661373 DOI: 10.1038/s41565-020-0728-z] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 06/03/2020] [Indexed: 05/27/2023]
Abstract
Van der Waals heterostructures obtained via stacking and twisting have been used to create moiré superlattices1, enabling new optical and electronic properties in solid-state systems. Moiré lattices in twisted bilayers of transition metal dichalcogenides (TMDs) result in exciton trapping2-5, host Mott insulating and superconducting states6 and act as unique Hubbard systems7-9 whose correlated electronic states can be detected and manipulated optically. Structurally, these twisted heterostructures feature atomic reconstruction and domain formation10-14. However, due to the nanoscale size of moiré domains, the effects of atomic reconstruction on the electronic and excitonic properties have not been systematically investigated. Here we use near-0°-twist-angle MoSe2/MoSe2 bilayers with large rhombohedral AB/BA domains15 to directly probe the excitonic properties of individual domains with far-field optics. We show that this system features broken mirror/inversion symmetry, with the AB and BA domains supporting interlayer excitons with out-of-plane electric dipole moments in opposite directions. The dipole orientation of ground-state Γ-K interlayer excitons can be flipped with electric fields, while higher-energy K-K interlayer excitons undergo field-asymmetric hybridization with intralayer K-K excitons. Our study reveals the impact of crystal symmetry on TMD excitons and points to new avenues for realizing topologically non-trivial systems16,17, exotic metasurfaces18, collective excitonic phases19 and quantum emitter arrays20,21 via domain-pattern engineering.
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Affiliation(s)
- Jiho Sung
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - You Zhou
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Giovanni Scuri
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Viktor Zólyomi
- National Graphene Institute, University of Manchester, Manchester, UK
- Hartree Centre, STFC Daresbury Laboratory, Daresbury, UK
| | | | - Hyobin Yoo
- Department of Physics, Harvard University, Cambridge, MA, USA
- Department of Physics, Sogang University, Seoul, Republic of Korea
| | - Dominik S Wild
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Andrew Y Joe
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Ryan J Gelly
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Hoseok Heo
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Department of Physics, Harvard University, Cambridge, MA, USA
| | | | - Damien Bérubé
- Department of Physics, California Institute of Technology, Pasadena, CA, USA
| | - Andrés M Mier Valdivia
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | | | - Kenji Watanabe
- National Institute for Materials Science, Tsukuba, Japan
| | - Mikhail D Lukin
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Philip Kim
- Department of Physics, Harvard University, Cambridge, MA, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Vladimir I Fal'ko
- National Graphene Institute, University of Manchester, Manchester, UK.
- Henry Royce Institute for Advanced Materials, University of Manchester, Manchester, UK.
| | - Hongkun Park
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
- Department of Physics, Harvard University, Cambridge, MA, USA.
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7
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Scuri G, Andersen TI, Zhou Y, Wild DS, Sung J, Gelly RJ, Bérubé D, Heo H, Shao L, Joe AY, Mier Valdivia AM, Taniguchi T, Watanabe K, Lončar M, Kim P, Lukin MD, Park H. Electrically Tunable Valley Dynamics in Twisted WSe_{2}/WSe_{2} Bilayers. Phys Rev Lett 2020; 124:217403. [PMID: 32530686 DOI: 10.1103/physrevlett.124.217403] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Accepted: 05/06/2020] [Indexed: 05/25/2023]
Abstract
The twist degree of freedom provides a powerful new tool for engineering the electrical and optical properties of van der Waals heterostructures. Here, we show that the twist angle can be used to control the spin-valley properties of transition metal dichalcogenide bilayers by changing the momentum alignment of the valleys in the two layers. Specifically, we observe that the interlayer excitons in twisted WSe_{2}/WSe_{2} bilayers exhibit a high (>60%) degree of circular polarization (DOCP) and long valley lifetimes (>40 ns) at zero electric and magnetic fields. The valley lifetime can be tuned by more than 3 orders of magnitude via electrostatic doping, enabling switching of the DOCP from ∼80% in the n-doped regime to <5% in the p-doped regime. These results open up new avenues for tunable chiral light-matter interactions, enabling novel device schemes that exploit the valley degree of freedom.
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Affiliation(s)
- Giovanni Scuri
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Trond I Andersen
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - You Zhou
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Dominik S Wild
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Jiho Sung
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Ryan J Gelly
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Damien Bérubé
- Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
| | - Hoseok Heo
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Linbo Shao
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Andrew Y Joe
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Andrés M Mier Valdivia
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Takashi Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Marko Lončar
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Philip Kim
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Mikhail D Lukin
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Hongkun Park
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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D. Lubell W, Poupart J, Doan ND, Bérubé D, Hamdane Y, Medena C. Palladium-Catalyzed Arylation of N-Aminoimidazol-2-ones towards Synthesis of Constrained Phenylalanine Dipeptide Mimics. HETEROCYCLES 2019. [DOI: 10.3987/com-18-s(f)22] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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9
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Tugulea AM, Bérubé D, Giddings M, Lemieux F, Hnatiw J, Priem J, Avramescu ML. Nano-silver in drinking water and drinking water sources: stability and influences on disinfection by-product formation. Environ Sci Pollut Res Int 2014; 21:11823-11831. [PMID: 24458938 PMCID: PMC4177100 DOI: 10.1007/s11356-014-2508-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Accepted: 12/27/2013] [Indexed: 05/30/2023]
Abstract
Nano-silver is increasingly used in consumer products from washing machines and refrigerators to devices marketed for the disinfection of drinking water or recreational water. The nano-silver in these products may be released, ending up in surface water bodies which may be used as drinking water sources. Little information is available about the stability of the nano-silver in sources of drinking water, its fate during drinking water disinfection processes, and its interaction with disinfection agents and disinfection by-products (DBPs). This study aims to investigate the stability of nano-silver in drinking water sources and in the finished drinking water when chlorine and chloramines are used for disinfection and to observe changes in the composition of DBPs formed when nano-silver is present in the source water. A dispersion of nano-silver particles (10 nm; PVP-coated) was used to spike untreated Ottawa River water, treated Ottawa River water, organic-free water, and a groundwater at concentrations of 5 mg/L. The diluted dispersions were kept under stirred and non-stirred conditions for up to 9 months and analyzed weekly using UV absorption to assess the stability of the nano-silver particles. In a separate experiment, Ottawa River water containing nano-silver particles (at 0.1 and 1 mg/L concentration, respectively) was disinfected by adding sodium hypochlorite (a chlorinating agent) in sufficient amounts to maintain a free chlorine residual of approximately 0.4 mg/L after 24 h. The disinfected drinking water was then quenched with ascorbic acid and analyzed for 34 neutral DBPs (trihalomethanes, haloacetonitriles, haloacetaldehydes, 1,1 dichloro-2-propanone, 1,1,1 trichloro-2-propanone, chloropicrin, and cyanogen chloride). The results were compared to the profile of DBPs obtained under the same conditions in the absence of nano-silver and in the presence of an equivalent concentration of Ag(+) ions (as AgNO3). The stability of the nano-silver dispersions in untreated Ottawa River water, with a dissolved organic carbon concentration of 6 mg/L, was significantly higher than the stability of the nano-silver dispersions in distilled, organic-free water. Nano-silver particles suspended in the groundwater agglomerated and were quickly and quantitatively removed from the solution. Our data confirm previous observations that natural dissolved organic matter stabilizes nano-silver particles, while the high-ionic strength of groundwater appears to favor their agglomeration and precipitation. As expected, nano-silver was not stable in Ottawa River water through the chlorination process, but survived for many days when added to the Ottawa River water after treatment with chlorine or chloramines. Stirring appeared to have minimal effect on nano-silver stability in untreated and treated Ottawa River water. The profile of DBPs formed in the presence of nAg differed significantly from the profile of DBPs formed in the absence of nAg only at the 1 mg/L nAg concentration. The differences observed consisted mainly in reduced formation of some brominated DBPs and a small increase in the formation of cyanogen chloride. The reduced formation of brominated congeners may be explained by the decrease in available bromide due to the presence of Ag(+) ions. It should be noted that a concentration of 1 mg/L is significantly higher than nAg concentrations that would be expected to be present in surface waters, but these results could be significant for the disinfection of some wastewaters with comparably high nano-silver concentrations.
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Moussa A, Villeneuve A, Lachance C, Krammoh E, Bérubé D, Bigras JL. Pulmonary Artery Pressure Variations in Infants with Bronchopulmonary Dysplasia. Paediatr Child Health 2009. [DOI: 10.1093/pch/14.suppl_a.35ab] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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11
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Bérubé D. Montelukast as controller monotherapy for Canadian pediatric asthma patients. J Allergy Clin Immunol 2003. [DOI: 10.1016/s0091-6749(03)80471-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
This article describes a novel case management program implemented by the Canadian Forces Health Services to care for its ill and injured members. A brief overview of the military environment is followed by the reasons why the military looked to the civilian sector and selected case management as a strategy for its continuity of care issues. Principles guiding the design and operations of the program are highlighted along with a description of the core case management activities. Staff roles are outlined including the reasoning behind hiring baccalaureate prepared civilian nurses as Case Managers. The article ends with a description of its current status and notes that preliminary member satisfaction findings demonstrate that nurses are making a positive difference in lives of soldiers that are ill or injured.
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Affiliation(s)
- D Bérubé
- Canadian Forces Health Services in Ottawa, Ontario
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13
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Vincent R, Kumarathasan P, Goegan P, Bjarnason SG, Guénette J, Bérubé D, Adamson IY, Desjardins S, Burnett RT, Miller FJ, Battistini B. Inhalation toxicology of urban ambient particulate matter: acute cardiovascular effects in rats. Res Rep Health Eff Inst 2001:5-54; discussion 55-62. [PMID: 11833973] [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] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
Wistar rats were exposed for 4 hours by nose-only inhalation to clean air, resuspended Ottawa ambient particles (EHC-93*, 48 mg/m3), the water-leached particles (EHC-93L, 49 mg/m3), diesel soot (5 mg/m3), or carbon black (5 mg/m3). Continuous data for physiologic endpoints (heart rate, blood pressure, body temperature, animal's activity) were captured by telemetry before and after exposure. Blood was sampled from jugular cannulas 1 to 3 days before exposure and at 2 and 24 hours after exposure, and by heart puncture on termination at 32 hours (histology group) or 48 hours (telemetry group) after exposure. Lung injury was assessed by 3H-thymidine autoradiography after the rats were killed. We measured endothelins (plasma ET-1, big ET-1, ET-2, ET-3) to assess the vasopressor components; nitric oxide (NO)-related metabolites (blood nitrate, nitrite, nitrosyl compounds, and plasma 3-nitrotyrosine) to assess the vasodilator components; and catecholamines (epinephrine, norepinephrine, L-DOPA, dopamine) and oxidative stressors (m- and o-tyrosine) for additional insight into possible stress components. Lung cell labeling was uniformly low in all treatment groups, which indicates an absence of acute lung injury. Inhalation of EHC-93 caused statistically significant elevations (P < 0.05) of blood pressure on day 2 after exposure, plasma ET-1 at 32 hours after exposure, and ET-3 at 2, 32, and 48 hours after exposure. In contrast, the modified EHC-93L particles, from which soluble components had been extracted, did not affect blood pressure. The EHC-93L particles caused early elevation (P < 0.05) of the plasma levels of ET-1, ET-2, and ET-3 at 2 hours after exposure, but the endothelins returned to basal levels 32 hours after exposure. Exposure to diesel soot, but not carbon black, caused an elevation (P < 0.05) of plasma ET-3 at 36 hours after exposure; blood pressure was not affected by diesel soot. Our results indicate that inhalation of the urban particles EHC-93 can affect blood levels of ET-1 and ET-3 and cause a vasopressor response in Wistar rats without causing acute lung injury. Furthermore, the potency of the particles to influence hemodynamic changes appears to be modified by removing polar organic compounds and soluble elements. Because the pathophysiologic significance of elevated endothelins has been clinically established in humans, our observations suggest a novel mechanism by which inhaled particles may cause cardiovascular effects. These findings in rats contribute to the weight of evidence in favor of a biologically plausible epidemiologic association between ambient particulate matter and cardiovascular morbidity and mortality in human populations.
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Affiliation(s)
- R Vincent
- Safe Environments Programme, Health Canada, Ottawa, Ontario
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14
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Boulet LP, Bai TR, Becker A, Bérubé D, Beveridge R, Bowie DM, Chapman KR, Côté J, Cockcroft D, Ducharme FM, Ernst P, FitzGerald JM, Kovesi T, Hodder RV, O'Byrne P, Rowe B, Sears MR, Simons FE, Spier S. What is new since the last (1999) Canadian Asthma Consensus Guidelines? Can Respir J 2001; 8 Suppl A:5A-27A. [PMID: 11360044 DOI: 10.1155/2001/278435] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The objective of the present document is to review the impact of new information on the recommendations made in the last (1999) Canadian Asthma Consensus Guidelines. It includes relevant published studies and observations or comments regarding what are considered to be the main issues in asthma management in children and adults in office, emergency department, hospital and clinical settings. Asthma is still insufficiently controlled in a large number of patients, and practice guidelines need to be integrated better with current care. This report re-emphasises the need for the following: objective measures of airflow obstruction to confirm the diagnosis of asthma suggested by the clinical evaluation; identification of contributing factors; and the establishment of a treatment plan to rapidly obtain and maintain optimal asthma control according to specific criteria. Recent publications support the essential role of asthma education and environmental control in asthma management. They further support the role of inhaled corticosteroids as the mainstay of anti-inflammatory therapy of asthma, and of both long acting beta2-agonists and leukotriene antagonists as effective means to improve asthma control when inhaled corticosteroids are insufficient. New developments, such as combination therapy, and recent major trials, such as the Children's Asthma Management Project (CAMP) study, are discussed.
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15
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Bérubé D, Chirron R. Asthma education: the impact on care: the Quebec experience. Pediatr Pulmonol 2001; Suppl 23:16-7. [PMID: 11886129] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Affiliation(s)
- D Bérubé
- Service de Pneumologie, Hĵpital Ste-Justine, Université de Montréal, PQ, Canada
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16
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Boulet LP, Becker A, Bérubé D, Beveridge R, Ernst P. [Summary of the recommendations of the Canadian Consensus Conference on Asthma 1999. Canadian Asthma Consensus Group]. CMAJ 1999; 161:SF1-14. [PMID: 10906908 PMCID: PMC1230848] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Affiliation(s)
- L P Boulet
- Institut de cardiologie et de pneumologie de l'Université Laval, Hôpital Laval, Sainte-Foy, Qué.
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17
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Boulet LP, Becker A, Bérubé D, Beveridge R, Ernst P. Canadian Asthma Consensus Report, 1999. Canadian Asthma Consensus Group. CMAJ 1999; 161:S1-61. [PMID: 10906907 PMCID: PMC1230847] [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] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
OBJECTIVES To provide physicians with current guidelines for the diagnosis and optimal management of asthma in children and adults, including pregnant women and the elderly, in office, emergency department, hospital and clinic settings. OPTIONS The consensus group considered the roles of education, avoidance of provocative environmental and other factors, diverse pharmacotherapies, delivery devices and emergency and in-hospital management of asthma. OUTCOMES Provision of the best control of asthma by confirmation of the diagnosis using objective measures, rapid achievement and maintenance of control and regular follow-up. EVIDENCE The key diagnostic and therapeutic recommendations are based on the 1995 Canadian guidelines and a critical review of the literature by small groups before a full meeting of the consensus group. Recommendations are graded according to 5 levels of evidence. Differences of opinion were resolved by consensus following discussion. VALUES Respirologists, immunoallergists, pediatricians and emergency and family physicians gave prime consideration to the achievement and maintenance of optimal control of asthma through avoidance of environmental inciters, education of patients and the lowest effective regime of pharmacotherapy to reduce morbidity and mortality. BENEFITS, HARMS AND COSTS Adherence to the guidelines should be accompanied by significant reduction in patients' symptoms, reduced morbidity and mortality, fewer emergency and hospital admissions, fewer adverse side-effects from medications, better quality of life for patients and reduced costs. RECOMMENDATIONS Recommendations are included in each section of the report. In summary, after a diagnosis of asthma is made based on clinical evaluation, including demonstration of variable airflow obstruction, and contributing factors are identified, a treatment plan is established to obtain and maintain optimal asthma control. The main components of treatment are patient education, environmental control, pharmacotherapy tailored to the individual and regular follow-up. VALIDATION The recommendations were distributed to the members of the Canadian Thoracic Society Asthma and Standards Committees, as well as members of the board of the Canadian Thoracic Society. In addition, collaborating groups representing the Canadian Association of Emergency Physicians, the Canadian College of Family Physicians, the Canadian Paediatric Society and the Canadian Society of Allergy and Immunology were asked to validate the recommendations. The recommendations were discussed at regional meetings throughout Canada. They were also compared with the recommendations of other similar groups in other countries. DISSEMINATION AND IMPLEMENTATION: An implementation committee has established a strategy for disseminating these guidelines to physicians, other health professionals and patients and for developing tools and means that will help integrate the recommendations into current asthma care. The plan is outlined in this report.
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Affiliation(s)
- L P Boulet
- Centre de pneumologie, Institut de cardiologie et de pneumologie de l'Université Laval, Hôpital Laval, Sainte-Foy, Que
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Renzi PM, Turgeon JP, Marcotte JE, Drblik SP, Bérubé D, Gagnon MF, Spier S. Reduced interferon-gamma production in infants with bronchiolitis and asthma. Am J Respir Crit Care Med 1999; 159:1417-22. [PMID: 10228104 DOI: 10.1164/ajrccm.159.5.9805080] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.9] [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: 11/16/2022] Open
Abstract
Infants are at increased risk of developing asthma after acute bronchiolitis. We assessed the hypothesis that cytokine production is related to the development of asthma after bronchiolitis. The smoking history and the presence of atopy or asthma in parents or siblings were recorded and blood mononuclear cell interferon (IFN)-gamma and interleukin (IL)-4 production in response to IL-2 were assessed in 32 infants hospitalized for bronchiolitis and in a subgroup (n = 19) in which pulmonary function tests were performed approximately 4.9 mo later. The presence of asthma was determined by the Delphi consensus method 2 yr after hospitalization. Infants were classified as follows: asthma absent (A, n = 14), possible (Po, n = 9), or probable (Pr, n = 9). Infants with possible and probable asthma had lower IFN-gamma production at the time of bronchiolitis and a trend to lower IFN-gamma production 4.9 mo later when compared with those who had no asthma. At the time of bronchiolitis, IFN-gamma production was: 123 +/- 31 versus 34 +/- 20 versus 21 +/- 14 pg/ml, A versus Po versus Pr (p = 0.02, ANOVA) and 4.9 mo after bronchiolitis, IFN-gamma production was: 147.3 +/- 45 versus 47.4 +/- 30 versus 22.3 +/- 32 pg/ml, No versus Po versus Pr (p = 0.08 ANOVA). IL-4 production did not differ between groups. Infants who went on to develop asthma had more parent smokers (21.4% versus 55. 6% versus 55.6%, A versus Po versus Pr, p < 0.04), lower VmaxFRC (122 +/- 18 versus 77 +/- 7 versus 67 +/- 8% predicted, A versus Po versus Pr, p < 0.02), lower PC40 histamine (6.4 +/- 3.3 versus 1.2 +/- 0.6 mg/ml, A versus Po+Pr, p < 0.03) but no increase in atopy or asthma in their family. Significant positive correlations were found between IFN-gamma production at the time of bronchiolitis and VmaxFRC (r = 0.606) or PC40 histamine (r = 0.648) 4.9 mo after bronchiolitis. Lower IFN-gamma production at the time of bronchiolitis is an indicator of lower pulmonary function and increased responsiveness to histamine 4.9 mo after bronchiolitis and is related to the development of asthma after bronchiolitis in infants.
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Affiliation(s)
- P M Renzi
- Ste-Justine and C.H.U.M. Research Centers, Pulmonary Units of Ste-Justine and Notre Dame Hospitals, University of Montreal, Respiratory Health Network of Centers of Excellence of Canada, Quebec, Canada
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19
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Boulet LP, Becker A, Bérubé D, Ernst P, Beveridge R. 1998 revision of the Canadian Asthma Consensus Guidelines. Asthma Consensus Conference Editorial Committee. Can Respir J 1999; 6:231-2. [PMID: 10393284 DOI: 10.1155/1999/149831] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- L P Boulet
- Institut de cardiologie et de pneumologie de l'Université Laval, Hôpital Laval, Sainte-Foy, Canada
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Theophile D, Bérubé D, Augé J, Vekemans M. Absence of genomic imprinting at the DiGeorge locus. Acta Genet Med Gemellol (Roma) 1996; 45:277-280. [PMID: 8872046 DOI: 10.1017/s0001566000001458] [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: 05/22/2023]
Abstract
Fluorescence in situ hybridization (FISH) has been used to visualize specific genomic DNA sequences in interphase nuclei. Timing of replication can be measured by FISH to interphase nuclei: nuclei with a sequence that has not replicated reveal two single signals (G1), whereas those in which the sequence has replicated show two signal doublets (G2). Asynchronous nuclei show a single signal on one allele and a double hybridization dot on the other homologue. In general, most sequences replicate synchronously on the two homologues, with only 10% of nuclei showing an asynchronous hybridization pattern. However, for the sequences known about to be imprinted, approximately 30% of nuclei reveal asynchronous replication. Little is known whether or not the proximal region of chromosome 22, involved in the DiGeorge syndrome [1], is imprinted. We have, therefore, examined the replication timing pattern of the DiGeorge critical region (DGCR).
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Affiliation(s)
- D Theophile
- Laboratoire d'Histologie-Embryologie et de Cytogénétique, Hopital Necker-Enfants-Malades, Paris, France
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Abstract
Relatively little is known of the chronic effects attributable to the ingestion of inorganic components such as uranium and silicon. Although ingestion of large amounts of U can cause acute renal damage through a chemical effect, studies on humans have typically considered inhalation the route of exposure. We investigated the association between drinking water concentration levels of U and Si, and microalbuminuria, a sensitive biological indicator of renal dysfunction. Linear regression analysis revealed a statistically significant association between U cumulative exposure index and albumin per mmol creatinine (P = 0.03). No such significant relationship appeared for Si, although a positive trend was witnessed. Since normal but increasing levels of microalbuminuria were observed at U concentration levels below the Canadian Maximum Allowable Concentration (MAC), it is suggested that further study be undertaken.
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Affiliation(s)
- Y Mao
- Cancer Bureau, Laboratory Centre for Disease Control, Health Canada, Ottawa, Ontario, Canada
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Boulet LP, d'Amours P, Bérubé D, Rouleau M, Parent JG, Pelletier C, Touchette C. [Update on inhalation therapy in asthma and obstructive bronchopulmonary diseases]. Union Med Can 1994; 123:23-31. [PMID: 8109063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Significant changes have occurred in aerosol therapy in the last few years. New devices have been developed to facilitate the administration of bronchodilator or anti-inflammatory drugs into the airways. Metered-dose inhaler with or without a spacer or powder devices are now considered the ideal mode of administration of aerosolized medications in the regular treatment of child or adult asthma as well as in COPD. In mild to moderate acute asthma, bronchodilators are ideally administered with a metered dose inhaler with a spacer device, nebulisation being required in only a minority of patients. Powder devices such as the Turbuhaler may also be useful in acute asthma but inspiratory flow should be sufficient, and their usefulness in this context remains to be better determined. In severe acute asthma or in patients unable to properly use the other inhalation devices, nebulisation can be used, with oxygen in the case of acute asthma. In patients requiring mechanical ventilation, administration of bronchodilators can be done with a metered-dose inhaler with a spacer device specifically designed for this purpose: it will replace nebulisation in most cases. In young children and infants unable to use spacer devices with a mouthpiece (< 5 years), wet nebulisation is still used during acute attacks of asthma. In these circumstances, the use of metered-dose inhalers with a spacer and mask are probably appropriate in some children but further studies are required to recommend their use.
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Solberg R, Sistonen P, Träskelin AL, Bérubé D, Simard J, Krajci P, Jahnsen T, de la Chapelle A. Mapping of the regulatory subunits RI beta and RII beta of cAMP-dependent protein kinase genes on human chromosome 7. Genomics 1992; 14:63-9. [PMID: 1358799 DOI: 10.1016/s0888-7543(05)80284-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The genes encoding the regulatory subunits RI beta (locus PRKAR1B) and RII beta (locus PRKAR2B) of human cAMP-dependent protein kinase have been mapped in the basic CEPH (Centre d'Etude du Polymorphisme Humain) family panel of 40 families to chromosome 7p and 7q, respectively, using the enzymes HindIII and BanII recognizing the corresponding restriction fragment length polymorphisms (RFLPs). Previous data from the CEPH database and our present RFLP data were used to construct a six-point local framework map including PRKAR1B and a seven-point framework map including PRKAR2B. The analysis placed PRKAR1B as the most distal of the hitherto mapped 7p marker loci and resulted in an unequivocal order of pter-PRKAR1B-D7S21-D7S108-D7S17-D7S149- D7S62-cen, with a significantly higher rate of male than female recombination between PRKAR1B and D7S21. The 7q regulatory gene locus, PRKAR2B, could also be placed in an unambigous order with regard to the existing CEPH database 7q marker loci, the resulting order being cen-D7S371-(COL1A2,D7S79)-PRKAR2B-MET-D7S87++ +-TCRB-qter. Furthermore, in situ hybridization to metaphase chromosomes physically mapped PRKAR2B to band q22 on chromosome 7.
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Affiliation(s)
- R Solberg
- Laboratory for Gene Technology, Rikshospitalet, Oslo, Norway
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Bérubé D, Gagné R. Definition of a small chromosomal rearrangement on chromosome 11p14 by molecular cytogenetics in situ hybridization. CLIN INVEST MED 1992; 15:489-93. [PMID: 1286530] [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] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Chromosomal in situ hybridization allows the detection and the definition of single copy DNA segments of very small size. In a particular case, we demonstrate the inactivity of this molecular cytogenetic technique. In this case, karyotype analysis revealed a chromosome 11p+. In situ hybridization of probes PBGD, D11S29, NCAM, and ETSI located at 11q23-qter shows that the extra chromosomal material on chromosome 11p+ is a duplication of the 11q23-qter region.
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Affiliation(s)
- D Bérubé
- Department of Human Genetics, Laval Medical Center, Ste-Foy, Quebec
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26
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Simard J, Bérubé D, Sandberg M, Grzeschik KH, Gagné R, Hansson V, Jahnsen T. Assignment of the gene encoding the catalytic subunit C beta of cAMP-dependent protein kinase to the p36 band on chromosome 1. Hum Genet 1992; 88:653-7. [PMID: 1551670 DOI: 10.1007/bf02265292] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [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: 12/27/2022]
Abstract
A cDNA for the human catalytic subunit (C beta) of cAMP-dependent protein kinase (PKA) has been cloned from a testis cDNA library. In the present study, we have determined the chromosomal localization of this gene using a cDNA for C beta as a probe. Southern blot analysis of genomic DNA from human/mouse cell hybrids revealed that the presence or absence of a 20-kb XbaI fragment, which hybridized with the C beta probe, was concordant with the presence of human chromosome 1. In situ hybridization to metaphase chromosome confirmed the somatic cell hybrid data and regionally mapped the C beta gene of PKA to the p36 band on chromosome 1.
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Affiliation(s)
- J Simard
- MRC Group in Molecular Endocrinology, CHUL Research Center and Laval University, Québec, Canada
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Foss KB, Simard J, Bérubé D, Beebe SJ, Sandberg M, Grzeschik KH, Gagné R, Hansson V, Jahnsen T. Localization of the catalytic subunit C gamma of the cAMP-dependent protein kinase gene (PRKACG) to human chromosome region 9q13. Cytogenet Cell Genet 1992; 60:22-5. [PMID: 1339328 DOI: 10.1159/000133286] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A cDNA for a new catalytic subunit (C gamma) of the cAMP-dependent protein kinase (PKA) was recently isolated from a human testis cDNA library. This subunit was shown to be expressed only in testis, and has so far not been demonstrated in other species. In the present study, we have determined the chromosomal localization of this gene employing a cDNA for C gamma as a probe. Southern blot analysis of genomic DNA from human x mouse somatic cell hybrids allowed us to assign this gene (PRKACG) to human chromosome 9. In situ hybridization to metaphase chromosomes confirmed the somatic cell hybrid data and regionally mapped the C gamma gene of PKA to human chromosome 9q13.
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Affiliation(s)
- K B Foss
- Institute of Medical Biochemistry, Rikshospitalet, University of Oslo, Norway
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29
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Orstavik S, Sandberg M, Bérubé D, Natarajan V, Simard J, Walter U, Gagné R, Hansson V, Jahnsen T. Localization of the human gene for the type I cyclic GMP-dependent protein kinase to chromosome 10. Cytogenet Cell Genet 1992; 59:270-3. [PMID: 1544322 DOI: 10.1159/000133267] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We have recently characterized cDNAs and genomic DNA fragments for human type I cGMP-dependent protein kinase (cGK). By probing human x hamster hybrid cell lines with a 1.2-kb intron fragment from the human type I cGK gene, we identified a 5.9-kb BglII restriction fragment and localized it to human chromosome 10. In situ hybridization analyses using 3H-labeled cDNA and genomic DNA probes for the human type I cGK to human metaphase chromosomes supported the somatic cell hybrid data and indicated that the gene (PRKG1B; protein kinase, cGMP-dependent) maps to 10p11.2----q11.2.
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Affiliation(s)
- S Orstavik
- Institute of Medical Biochemistry, Rikshospitalet, University of Oslo, Norway
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30
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31
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Bérubé D, Cartier A, L'Archevêque J, Ghezzo H, Malo JL. Comparison of peak expiratory flow rate and FEV1 in assessing bronchomotor tone after challenges with occupational sensitizers. Chest 1991; 99:831-6. [PMID: 2009783 DOI: 10.1378/chest.99.4.831] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.7] [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: 12/29/2022] Open
Abstract
Bronchial responses to occupational sensitizers measured by peak expiratory flow rate (PEFR) and forced expiratory volume in 1 s (FEV1) during late reactions (between 90 minutes and 8 hours after exposure) were compared in two groups of 88 subjects who had undergone specific inhalation challenges in the laboratory. The first group had what was considered a positive reaction (a fall of at least 15 percent in FEV1) whereas the second group's reaction was interpreted as negative (fall in FEV1 less than 15 percent). Although the correlation in terms of percentage of change from baseline values was statistically significant, the correspondence was poor. PEFR proved far less sensitive than FEV1 in detecting a reaction. Whereas the mean maximum change in FEV1 overall was 27 percent, the mean maximum change in PEFR at the same time interval was only 16 percent. Moreover, individual correlations between the percentage of change in FEV1 and PEFR were satisfactory (r2 greater than 0.80) in only 32/88 subjects (36 percent). No subject who was considered to have a negative challenge according to FEV1 had a change in PEFR greater than 20 percent. We therefore conclude that changes in PEFR are far less sensitive than changes in FEV1 in detecting responses during late reactions to occupational sensitizers.
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Affiliation(s)
- D Bérubé
- Department of Chest Medicine, Hôpital du Sacré-Coeur, Montreal, Canada
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32
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Bérubé D, Kröger H, Lafrance R, Marleau L. Yang-Mills theory on a momentum lattice: Gauge invariance, chiral invariance, and no fermion doubling. Int J Clin Exp Med 1991; 43:1385-1392. [PMID: 10013509 DOI: 10.1103/physrevd.43.1385] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Seralini GE, Bérubé D, Gagné R, Hammond GL. The human corticosteroid binding globulin gene is located on chromosome 14q31-q32.1 near two other serine protease inhibitor genes. Hum Genet 1990; 86:73-5. [PMID: 2253941 DOI: 10.1007/bf00205177] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [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: 12/31/2022]
Abstract
Human corticosteroid binding globulin (CBG) cDNA fragments were radiolabeled and hybridized in situ to metaphase chromosome preparations. The results localized the CBG gene to the q31-q32.1 region of human chromosome 14. This location also contains the genes for two closely related serine protease inhibitors: alpha 1-proteinase inhibitor and alpha 1-antichymotrypsin. It is therefore likely that these genes evolved by duplication events, and it would appear that this region contains a series of functionally related genes.
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Affiliation(s)
- G E Seralini
- Department of Obstetrics and Gynecology, University of Western Ontario, London, Canada
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Luu-The V, Labrie C, Zhao HF, Couët J, Lachance Y, Simard J, Côté J, Leblanc G, Lagacé L, Bérubé D. Purification, cloning, complementary DNA structure, and predicted amino acid sequence of human estradiol 17 beta-dehydrogenase. Ann N Y Acad Sci 1990; 595:40-52. [PMID: 2197970 DOI: 10.1111/j.1749-6632.1990.tb34281.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- V Luu-The
- MRC Group in Molecular Endocrinology, Research Centre, Laval University Medical Centre, Quebec, Canada
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35
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Affiliation(s)
- D Bérubé
- Department of Human Genetics, Laval Medical Center, Ste-Foy, Quebec, Canada
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36
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Bérubé D, Passage E, Mattei MG, Mattei JF, Gagné R. Fine mapping of the long arm of human chromosome 11 by in situ hybridization using different translocations, including the t(11;22) of Ewing sarcoma. Cytogenet Cell Genet 1990; 54:142-7. [PMID: 2265556 DOI: 10.1159/000132978] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The progesterone receptor gene (PGR), the gene coding for porphobilinogen deaminase (PBGD), the gene coding for a neural cell adhesion molecule (NCAM), the oncogene ETS1, and the anonymous genomic sequence D11S29 have been previously located on the long arm of chromosome 11. However, gene localizations obtained with different gene-mapping procedures have led to occasional discrepancies. To localize these genes more precisely, we hybridized five human DNA sequences with different chromosomal rearrangements, including four balanced and one unbalanced translocations. We show here that the order of these five sequences is cen-PGR-PBGD-DIIS29/NCAM/ETS1-tel.
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Affiliation(s)
- D Bérubé
- Département de Génétique humaine, Centre Hospitalier de l'Université Laval, Québec, Canada
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Bérubé D, Séralini GE, Gagné R, Hammond GL. Localization of the human sex hormone-binding globulin gene (SHBG) to the short arm of chromosome 17 (17p12----p13). Cytogenet Cell Genet 1990; 54:65-7. [PMID: 2249477 DOI: 10.1159/000132958] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Human sex hormone-binding globulin (SHBG) is a plasma steroid transport protein which is known to be encoded by an autosomal gene. We have hybridized two separate cDNA probes, corresponding to the 5' and 3' portions of the coding sequence for SHBG, to human metaphase chromosomes in situ. In this way, the SHBG gene has been localized to the p12----p13 bands of chromosome 17.
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Affiliation(s)
- D Bérubé
- Department of Molecular Genetics, Laval University Medical Centre, Quebec, Canada
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Luu The V, Labrie C, Zhao HF, Couët J, Lachance Y, Simard J, Leblanc G, Côté J, Bérubé D, Gagné R. Characterization of cDNAs for human estradiol 17 beta-dehydrogenase and assignment of the gene to chromosome 17: evidence of two mRNA species with distinct 5'-termini in human placenta. Mol Endocrinol 1989; 3:1301-9. [PMID: 2779584 DOI: 10.1210/mend-3-8-1301] [Citation(s) in RCA: 207] [Impact Index Per Article: 5.9] [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: 01/02/2023] Open
Abstract
Human placenta estradiol 17 beta-dehydrogenase (E2DH) cDNA clones were isolated from a lambda gt11 expression library by screening with 33 mer synthetic oligonucleotides derived from the amino acid sequence of the catalytic site of E2DH and with polyclonal antibodies raised against the enzyme purified from human placenta. Using 32P-labeled fragments from the coding and 5'-untranslated regions, two mRNA species have been identified in poly(A)+ RNA from human placenta, a major species migrating at 1.3 kilobases (kb) while a minor one is found at 2.2 kb. Primer extension analysis identifies the major mRNA as starting 9-10 nucleotides upstream from the in-frame ATG initiating codon while the longer mRNA has at least 814 noncoding nucleotides at its 5'-terminus. Sequence analysis of the longest cDNA clone (2092 base pairs) shows that this clone possesses identical coding and noncoding sequences in the regions of overlap with the shorter cDNA clones. The 32P-labeled 5'-noncoding fragment hybridized only to the 2.2 kb band, thus providing additional evidence for the existence of two distinct mRNA species which differ only in their 5'-noncoding regions. Using hpE2DH36 cDNA as a probe for in situ hybridization, the human E2DH gene was localized to the q11-q12 region of chromosome 17. The cloned cDNAs encode E2DH, a 327-amino acid protein having a calculated molecular weight of 34,853. Since E2DH is the enzyme required for the formation of 17 beta-estradiol, the availability of the cDNA encoding the enzyme should permit a detailed investigation of the factors regulating the expression and activity of this crucial enzyme, in both normal and malignant tissues, especially breast cancer.
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Affiliation(s)
- V Luu The
- Department of Molecular Endocrinology, Laval University Medical Centre, Quebec, Canada
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Labrie F, Luu-The V, Labrie C, Bérubé D, Couet J, Zhao HF, Gagné R, Simard J. Characterization of two mRNA species encoding human estradiol 17 beta-dehydrogenase and assignment of the gene to chromosome 17. J Steroid Biochem 1989; 34:189-97. [PMID: 2483219 DOI: 10.1016/0022-4731(89)90082-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Using two 33-mer synthetic oligonucleotides derived from the amino acid sequence of the catalytic site of estradiol 17 beta-dehydrogenase (E2DH) and polyclonal antibodies raised against the enzyme purified from human placenta, clones were isolated from a lambda gt11 human placental cDNA library. A 327-amino acid sequence was deduced from cDNA sequencing. Two mRNA species have been identified in poly(A)+ RNA from human placenta, a major species migrating at 1.3 kb while a minor one is found at approx. 2.2 kb. Primer extension and S1 nuclease analysis indicate that the major mRNA species starts 9-10 nucleotides while the minor mRNA starts 971 nucleotides upstream from the ATG initiating codon, respectively. Sequence analysis of the longest cDNA clone (2092 bp) shows that it possesses identical coding and non-coding sequences in the regions of overlap with the shorter cDNA clones. The 32P-labeled 5' non-coding fragment hybridizes only to the 2.2 kb band, thus providing evidence for the existence of two distinct mRNA species which differ in their 5' noncoding regions. Using hp E2DH-36 cDNA as a probe for in situ hybridization of translocated chromosomes, the human E2DH gene was localized to the q11-q12 region of chromosome 17.
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Affiliation(s)
- F Labrie
- Department of Molecular Endocrinology, Laval University Medical Centre, Quebec, Canada
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Bérubé D, Luu The V, Lachance Y, Gagné R, Labrie F. Assignment of the human 3 beta-hydroxysteroid dehydrogenase gene (HSDB3) to the p13 band of chromosome 1. Cytogenet Cell Genet 1989; 52:199-200. [PMID: 2630193 DOI: 10.1159/000132878] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Three-beta-hydroxysteroid dehydrogenase (HSDB3) is the enzyme which catalyses the oxidative conversion of delta 5-3 beta-hydroxy steroids to the delta 4-3-keto configuration and is therefore involved in the biosynthesis of all classes of hormonal steroids, namely progesterone, glucocorticoids, mineralocorticoids, androgens, and estrogens. Deficiency of the enzyme is associated with congenital adrenal hyperplasia and is usually lethal in early life. Despite its crucial role, chromosome assignment of the gene for this enzyme has not been reported. Using in situ hybridization, we report that hybridization with labeled human HSDB3-specific cDNA yielded 27% of silver grains associated with chromosome 1 with a maximal concentration in the p13 band.
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Affiliation(s)
- D Bérubé
- Department of Molecular Genetics, Laval University Medical Centre, Québec, Canada
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Bérubé D, Kirouac D, Croteau D, Bergeron MG, Lebel M. Plasma bactericidal activity after administration of erythromycin estolate and erythromycin ethylsuccinate to healthy volunteers. Antimicrob Agents Chemother 1988; 32:1227-30. [PMID: 3142349 PMCID: PMC172382 DOI: 10.1128/aac.32.8.1227] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
In a crossover design study, we compared the plasma bactericidal activities of erythromycin estolate (500 mg) and erythromycin ethylsuccinate (600 mg) after administration of a single oral dose to 12 healthy volunteers. Both erythromycin esters displayed very good plasma bactericidal activities against Streptococcus pneumoniae. The median bactericidal titers produced in plasma against Streptococcus pyogenes and Streptococcus pneumoniae were significantly higher with erythromycin estolate than with the ethylsuccinate ester at both 2 and 8 h after dosing (P less than 0.05 by Student's t test). Both erythromycin esters showed rather weak bactericidal activity against Branhamella catarrhalis; a further look at these results indicated that erythromycin estolate presented 50% of the plasma samples at 2 h with bactericidal titers superior or equal to 1:8, versus 11% for the ethylsuccinate ester. Of the 60 plasma bactericidal activity tests performed against Staphylococcus aureus, only 6 (10%) and 3 (5%) exhibited titers of 1:8 or greater for erythromycin estolate and erythromycin ethylsuccinate, respectively. Clinical trials are warranted in which these products are compared in infections other than Streptococcus pyogenes pharyngitis, for which the clinical superiority of erythromycin estolate has been demonstrated.
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Affiliation(s)
- D Bérubé
- Ecole de Pharmacie, Université Laval, Quebec, Canada
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Bérubé D, Vallée F, Panneton AC, Bergeron MG, LeBel M. Pharmacokinetics of carumonam after single and multiple 1- and 2-g dosage regimens. Antimicrob Agents Chemother 1988; 32:354-7. [PMID: 3364953 PMCID: PMC172175 DOI: 10.1128/aac.32.3.354] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The pharmacokinetics of carumonam after single and multiple intravenous administration of 1- and 2-g dosage regimens were studied in 12 young male volunteers. Plasma and urine samples were collected in serial order for 24 h and assayed by high-pressure liquid chromatography. The mean elimination half-life of carumonam was not significantly affected by either dosage regimen or single dose versus steady state, ranging from 1.3 to 1.5 h. Mean concentrations at the end of the interval were not influenced by a multiple-dose administration. The normalized volume of distribution was independent of the dose, with values ranging from 0.16 to 0.19 liters/kg. After multiple administration, carumonam was cleared from the body more rapidly: from 96.2 to 121.7 ml/min after 1 g every 8 h, and from 102.1 to 122.3 ml/min after 2 g every 8 h (P less than 0.05). After 24 h, 75.0 to 80.7% of the dose was excreted unchanged in the urine. The protein binding of carumonam to human plasma remained stable at 28%. Carumonam was well tolerated by the volunteers.
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Affiliation(s)
- D Bérubé
- Ecole de Pharmacie, Université Laval, Quebec, Canada
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