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Du P, Chen Y, Li Q, Gai Z, Bai H, Zhang L, Liu Y, Cao Y, Zhai Y, Jin W. CancerMHL: the database of integrating key DNA methylation, histone modifications and lncRNAs in cancer. Database (Oxford) 2024; 2024:baae029. [PMID: 38613826 PMCID: PMC11015892 DOI: 10.1093/database/baae029] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/04/2024] [Accepted: 03/23/2024] [Indexed: 04/15/2024]
Abstract
The discovery of key epigenetic modifications in cancer is of great significance for the study of disease biomarkers. Through the mining of epigenetic modification data relevant to cancer, some researches on epigenetic modifications are accumulating. In order to make it easier to integrate the effects of key epigenetic modifications on the related cancers, we established CancerMHL (http://www.positionprediction.cn/), which provide key DNA methylation, histone modifications and lncRNAs as well as the effect of these key epigenetic modifications on gene expression in several cancers. To facilitate data retrieval, CancerMHL offers flexible query options and filters, allowing users to access specific key epigenetic modifications according to their own needs. In addition, based on the epigenetic modification data, three online prediction tools had been offered in CancerMHL for users. CancerMHL will be a useful resource platform for further exploring novel and potential biomarkers and therapeutic targets in cancer. Database URL: http://www.positionprediction.cn/.
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Affiliation(s)
- Pengyu Du
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, 235 West Daxue Road, Hohhot 010021, China
| | - Yingli Chen
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, 235 West Daxue Road, Hohhot 010021, China
- The State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, Inner Mongolia University, 235 West Daxue Road, Hohhot 010021, China
| | - Qianzhong Li
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, 235 West Daxue Road, Hohhot 010021, China
- The State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, Inner Mongolia University, 235 West Daxue Road, Hohhot 010021, China
| | - Zhimin Gai
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, 235 West Daxue Road, Hohhot 010021, China
| | - Hui Bai
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, 235 West Daxue Road, Hohhot 010021, China
| | - Luqiang Zhang
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, 235 West Daxue Road, Hohhot 010021, China
| | - Yuxian Liu
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, 235 West Daxue Road, Hohhot 010021, China
| | - Yanni Cao
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, 235 West Daxue Road, Hohhot 010021, China
| | - Yuanyuan Zhai
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, 235 West Daxue Road, Hohhot 010021, China
| | - Wen Jin
- Laboratory of Theoretical Biophysics, School of Physical Science and Technology, Inner Mongolia University, 235 West Daxue Road, Hohhot 010021, China
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Stukel M, Hariasz L, Di Stefano PCF, Rasco BC, Rykaczewski KP, Brewer NT, Stracener DW, Liu Y, Gai Z, Rouleau C, Carter J, Kostensalo J, Suhonen J, Davis H, Lukosi ED, Goetz KC, Grzywacz RK, Mancuso M, Petricca F, Fijałkowska A, Wolińska-Cichocka M, Ninkovic J, Lechner P, Ickert RB, Morgan LE, Renne PR, Yavin I. Rare ^{40}K Decay with Implications for Fundamental Physics and Geochronology. Phys Rev Lett 2023; 131:052503. [PMID: 37595241 DOI: 10.1103/physrevlett.131.052503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 05/09/2023] [Accepted: 05/19/2023] [Indexed: 08/20/2023]
Abstract
Potassium-40 is a widespread, naturally occurring isotope whose radioactivity impacts subatomic rare-event searches, nuclear structure theory, and estimated geological ages. A predicted electron-capture decay directly to the ground state of argon-40 has never been observed. The KDK (potassium decay) collaboration reports strong evidence of this rare decay mode. A blinded analysis reveals a nonzero ratio of intensities of ground-state electron-captures (I_{EC^{0}}) over excited-state ones (I_{EC^{*}}) of I_{EC^{0}}/I_{EC^{*}}=0.0095±[over stat]0.0022±[over sys]0.0010 (68% C.L.), with the null hypothesis rejected at 4σ. In terms of branching ratio, this signal yields I_{EC^{0}}=0.098%±[over stat]0.023%±[over sys]0.010%, roughly half of the commonly used prediction, with consequences for various fields [27L. Hariasz et al., companion paper, Phys. Rev. C 108, 014327 (2023)PRVCAN2469-998510.1103/PhysRevC.108.014327].
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Affiliation(s)
- M Stukel
- Department of Physics, Engineering Physics & Astronomy, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - L Hariasz
- Department of Physics, Engineering Physics & Astronomy, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - P C F Di Stefano
- Department of Physics, Engineering Physics & Astronomy, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - B C Rasco
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - K P Rykaczewski
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - N T Brewer
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Joint Institute for Nuclear Physics and Application, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - D W Stracener
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Y Liu
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Z Gai
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - C Rouleau
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - J Carter
- Berkeley Geochronology Center, Berkeley, California 94709, USA
| | - J Kostensalo
- Natural Resources Institute Finland, Joensuu FI-80100, Finland
| | - J Suhonen
- Department of Physics, University of Jyväskylä, Jyväskylä FI-40014, Finland
| | - H Davis
- Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
- Joint Institute for Advanced Materials, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - E D Lukosi
- Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
- Joint Institute for Advanced Materials, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - K C Goetz
- Nuclear and Extreme Environments Measurement Group, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - R K Grzywacz
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Joint Institute for Nuclear Physics and Application, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - M Mancuso
- Max-Planck-Institut für Physik, Munich D-80805, Germany
| | - F Petricca
- Max-Planck-Institut für Physik, Munich D-80805, Germany
| | - A Fijałkowska
- Faculty of Physics, University of Warsaw, Warsaw PL-02-093, Poland
| | - M Wolińska-Cichocka
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Joint Institute for Nuclear Physics and Application, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Heavy Ion Laboratory, University of Warsaw, Warsaw PL-02-093, Poland
| | - J Ninkovic
- MPG Semiconductor Laboratory, Munich D-80805, Germany
| | - P Lechner
- MPG Semiconductor Laboratory, Munich D-80805, Germany
| | - R B Ickert
- Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, Illinois 47907, USA
| | - L E Morgan
- U.S. Geological Survey, Geology, Geophysics, and Geochemistry Science Center, Denver, Colorado 80225, USA
| | - P R Renne
- Berkeley Geochronology Center, Berkeley, California 94709, USA
- Department of Earth and Planetary Science, University of California, Berkeley, California 94720, USA
| | - I Yavin
- Department of Physics, Engineering Physics & Astronomy, Queen's University, Kingston, Ontario K7L 3N6, Canada
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Joint Institute for Nuclear Physics and Application, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Berkeley Geochronology Center, Berkeley, California 94709, USA
- Natural Resources Institute Finland, Joensuu FI-80100, Finland
- Department of Physics, University of Jyväskylä, Jyväskylä FI-40014, Finland
- Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
- Joint Institute for Advanced Materials, University of Tennessee, Knoxville, Tennessee 37996, USA
- Nuclear and Extreme Environments Measurement Group, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
- Max-Planck-Institut für Physik, Munich D-80805, Germany
- Faculty of Physics, University of Warsaw, Warsaw PL-02-093, Poland
- Heavy Ion Laboratory, University of Warsaw, Warsaw PL-02-093, Poland
- MPG Semiconductor Laboratory, Munich D-80805, Germany
- Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, Illinois 47907, USA
- U.S. Geological Survey, Geology, Geophysics, and Geochemistry Science Center, Denver, Colorado 80225, USA
- Department of Earth and Planetary Science, University of California, Berkeley, California 94720, USA
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Liu ZQ, Li L, Gai Z, Clarkson JD, Hsu SL, Wong AT, Fan LS, Lin MW, Rouleau CM, Ward TZ, Lee HN, Sefat AS, Christen HM, Ramesh R. Full Electroresistance Modulation in a Mixed-Phase Metallic Alloy. Phys Rev Lett 2016; 116:097203. [PMID: 26991197 DOI: 10.1103/physrevlett.116.097203] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Indexed: 06/05/2023]
Abstract
We report a giant, ∼22%, electroresistance modulation for a metallic alloy above room temperature. It is achieved by a small electric field of 2 kV/cm via piezoelectric strain-mediated magnetoelectric coupling and the resulting magnetic phase transition in epitaxial FeRh/BaTiO_{3} heterostructures. This work presents detailed experimental evidence for an isothermal magnetic phase transition driven by tetragonality modulation in FeRh thin films, which is in contrast to the large volume expansion in the conventional temperature-driven magnetic phase transition in FeRh. Moreover, all the experimental results in this work illustrate FeRh as a mixed-phase model system well similar to phase-separated colossal magnetoresistance systems with phase instability therein.
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Affiliation(s)
- Z Q Liu
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
| | - L Li
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Z Gai
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - J D Clarkson
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
| | - S L Hsu
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
| | - A T Wong
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - L S Fan
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - M-W Lin
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - C M Rouleau
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - T Z Ward
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - H N Lee
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - A S Sefat
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - H M Christen
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - R Ramesh
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- Department of Physics, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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4
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Leite Ferreira B, Brandão P, Dos Santos A, Gai Z, Cruz C, Reis M, Santos T, Félix V. Heptacopper(II) and dicopper(II)-adenine complexes: synthesis, structural characterization, and magnetic properties. J COORD CHEM 2015. [DOI: 10.1080/00958972.2015.1061126] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
| | - Paula Brandão
- TEMA−NRD, Departamento de Engenharia Mecânica, Universidade de Aveiro, Aveiro, Portugal
| | - A.M. Dos Santos
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Z. Gai
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - C. Cruz
- Instituto de Física, Universidade Federal Fluminense, Niterói, Brazil
| | - M.S. Reis
- Instituto de Física, Universidade Federal Fluminense, Niterói, Brazil
| | - T.M. Santos
- CICECO, Departamento de Química, Universidade de Aveiro, Aveiro, Portugal
| | - V. Félix
- CICECO, Departamento de Química, Universidade de Aveiro, Aveiro, Portugal
- iBiMED, Departamento de Química, Universidade de Aveiro, Aveiro, Portugal
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5
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Zhang KHL, Du Y, Sushko PV, Bowden ME, Shutthanandan V, Qiao L, Cao GX, Gai Z, Sallis S, Piper LFJ, Chambers SA. Electronic and magnetic properties of epitaxial perovskite SrCrO₃(0 0 1). J Phys Condens Matter 2015; 27:245605. [PMID: 26037231 DOI: 10.1088/0953-8984/27/24/245605] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We have investigated the intrinsic properties of SrCrO3 epitaxial thin films synthesized by molecular beam epitaxy. We find compelling evidence that SrCrO3 is a correlated metal. X-ray photoemission valence band and O K-edge x-ray absorption spectra indicate a strongly hybridized Cr3d-O2p state crossing the Fermi level, leading to metallic behavior. Comparison between valence band spectra near the Fermi level and the densities of states calculated using density functional theory (DFT) suggests the presence of coherent and incoherent states and points to strong electron correlation effects. The magnetic susceptibility can be described by Pauli paramagnetism at temperatures above 100 K, but reveals antiferromagnetic behavior at lower temperatures, possibly resulting from orbital ordering.
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Affiliation(s)
- K H L Zhang
- Physical Sciences Division, Fundamental & Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA. Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, CB3 0FS, UK
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6
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Jiang J, Zhang X, Huo R, Li X, Yang Y, Gai Z, Xu M, Shen L, Cai L, Wan C, Li B, He L, Qin S. Association study of UGT1A9 promoter polymorphisms with DILI based on systematically regional variation screen in Chinese population. Pharmacogenomics J 2014; 15:326-31. [PMID: 25446781 DOI: 10.1038/tpj.2014.75] [Citation(s) in RCA: 7] [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: 03/27/2014] [Revised: 09/09/2014] [Accepted: 10/09/2014] [Indexed: 02/05/2023]
Abstract
Drug-induced liver injury (DILI) is caused by unpredictable adverse drug reaction due mainly to the accumulation of hepatotoxic compounds in the liver resulting in significant damage. Drug-metabolizing enzymes have been prime targets for molecular studies relevant to DILI. The gene UGT1A9 mainly expresses in the liver and has an important role in drug metabolism. The Han Chinese has a very long and complex demographic history, and the population stratification arising from the interplay of different geographic areas may influence the polymorphism pattern. We selected 260 healthy subjects in three different geographic areas (including Xian, Shanghai and Liuzhou) for systemic screening and analysis of single-nucleotide polymorphisms (SNPs) in the promoter region of UGT1A9. Eight SNPs were identified and no regional disparity exists among the three populations. Based on these results, 213 DILI patients from all over the Chinese mainland were further recruited to investigate possible association between UGT1A9 and DILI. We observed statistically significant associations between SNP rs2741045 and DILI at both allele and genotype levels (allele: P=0.032; genotype: P=0.029; after Bonferroni correction). Also, multivariate interaction analysis discovered the interaction between rs2741045 and age associated with DILI significantly. This is the first such screening study to investigate the association between UGT1A9 promoter polymorphisms and DILI in the Chinese population and it could provide the basis for further study of DILI mechanisms.
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Affiliation(s)
- J Jiang
- 1] Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China [2] Shanghai Genome Pilot Institutes for Genomics and Human Health, Shanghai, China
| | - X Zhang
- Department of Pharmacy, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China
| | - R Huo
- 1] Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China [2] Shanghai Genome Pilot Institutes for Genomics and Human Health, Shanghai, China
| | - X Li
- 1] Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China [2] Shanghai Genome Pilot Institutes for Genomics and Human Health, Shanghai, China
| | - Y Yang
- General Hospital of Ningxia Medical University, YinChuan, China
| | - Z Gai
- Jinan Infectious Disease Hospital, Shandong University, Jinan, China
| | - M Xu
- 1] Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China [2] Shanghai Genome Pilot Institutes for Genomics and Human Health, Shanghai, China
| | - L Shen
- 1] Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China [2] Shanghai Genome Pilot Institutes for Genomics and Human Health, Shanghai, China
| | - L Cai
- 1] Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China [2] Shanghai Genome Pilot Institutes for Genomics and Human Health, Shanghai, China
| | - C Wan
- 1] Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China [2] Shanghai Genome Pilot Institutes for Genomics and Human Health, Shanghai, China
| | - B Li
- 1] Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China [2] Shanghai Genome Pilot Institutes for Genomics and Human Health, Shanghai, China
| | - L He
- 1] Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China [2] Shanghai Genome Pilot Institutes for Genomics and Human Health, Shanghai, China [3] Children's Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - S Qin
- 1] Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China [2] Shanghai Genome Pilot Institutes for Genomics and Human Health, Shanghai, China
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Pramanick A, Lauter V, Wang XL, An K, Ambaye H, Goyette Jr RJ, Yi J, Gai Z, Stoica AD. Polarized neutron diffraction at a spallation source for magnetic studies. J Appl Crystallogr 2012. [DOI: 10.1107/s0021889812034474] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The availability of high-power spallation neutron sources, along with advances in the development of coupled moderators and neutron polarizers, has made it possible to use polarized neutrons on time-of-flight diffractometers forin situstudies of phenomena contributing to field-induced magnetization of a material. Different electronic and structural phenomena that contribute to the overall magnetization of a material can be studied and clearly identified with polarized neutron diffraction measurements. This article reports the first results from polarized neutron diffraction experiments on a time-of-flight instrument at a spallation source. Magnetic field-induced rotation of electron spins in an Ni–Mn–Ga single crystal was measured with polarized neutron diffraction at the MAGICS reflectometer at the Spallation Neutron Source at Oak Ridge National Laboratory. The difference in intensities measured with spin-up and spin-down polarized neutrons is proportional to the field-induced magnetization of the crystal. The polarized neutron measurements indicate that the magnetic form factor for the 3delectrons of Mn in Ni–Mn–Ga is lower than the value reported earlier for an ideal spherical symmetry of electronic distribution. Future experiments for studying field-induced magnetization in materials following the current methodology are outlined.
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Ward TZ, Gai Z, Xu XY, Guo HW, Yin LF, Shen J. Tuning the metal-insulator transition in manganite films through surface exchange coupling with magnetic nanodots. Phys Rev Lett 2011; 106:157207. [PMID: 21568612 DOI: 10.1103/physrevlett.106.157207] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Indexed: 05/30/2023]
Abstract
In strongly correlated electronic systems, the global transport behavior depends sensitively on spin ordering. We show that spin ordering in manganites can be controlled by depositing isolated ferromagnetic nanodots at the surface. The exchange field at the interface is tunable with nanodot density and makes it possible to overcome dimensionality and strain effects in frustrated systems to greatly increasing the metal-insulator transition and magnetoresistance. These findings indicate that electronic phase separation can be controlled by the presence of magnetic nanodots.
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Affiliation(s)
- T Z Ward
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA.
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Fuchigami K, Gai Z, Ward TZ, Yin LF, Snijders PC, Plummer EW, Shen J. Tunable metallicity of the La5/8Ca3/8MnO3(001) surface by an oxygen overlayer. Phys Rev Lett 2009; 102:066104. [PMID: 19257611 DOI: 10.1103/physrevlett.102.066104] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Indexed: 05/27/2023]
Abstract
We studied the surface structure of La_{5/8}Ca_{3/8}MnO_{3}(001) thin films using in situ scanning tunneling microscopy (STM). Atomically resolved STM images reveal that a (sqrt[2]xsqrt[2])R45;{ degrees } reconstructed surface and a (1x1) surface can be converted back and forth through adsorption and desorption of oxygen at the surface. The electrical properties of the surfaces are investigated by scanning tunneling spectroscopy. I-V curves clearly show that the presence of an oxygen overlayer renders the surface insulating while the (1x1) surface without the oxygen overlayer is metallic.
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Affiliation(s)
- K Fuchigami
- Materials Sciences and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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10
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Torija MA, Gai Z, Myoung N, Plummer EW, Shen J. Frozen low-spin interface in ultrathin Fe films on Cu(111). Phys Rev Lett 2005; 95:027201. [PMID: 16090711 DOI: 10.1103/physrevlett.95.027201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Indexed: 05/03/2023]
Abstract
In ultrathin film systems, it is a major challenge to understand how a thickness-driven phase transition proceeds along the cross-sectional direction of the films. We use ultrathin Fe films on Cu(111) as a prototype system to demonstrate how to obtain such information using an in situ scanning tunneling microscope and the surface magneto-optical Kerr effect. The magnetization depth profile of a thickness-driven low-spin to high-spin magnetic phase transition is deduced from the experimental data, which leads us to conclude that a low-spin Fe layer at the Fe/Cu interface stays live upon the phase transition. The magnetically live low-spin phase is believed to be induced by a frozen fcc Fe layer that survives a thickness-driven fcc-->bcc structural transition.
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Affiliation(s)
- M A Torija
- Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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11
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Pierce JP, Torija MA, Gai Z, Shi J, Schulthess TC, Farnan GA, Wendelken JF, Plummer EW, Shen J. Ferromagnetic stability in Fe nanodot assemblies on Cu(111) induced by indirect coupling through the substrate. Phys Rev Lett 2004; 92:237201. [PMID: 15245191 DOI: 10.1103/physrevlett.92.237201] [Citation(s) in RCA: 4] [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: 02/23/2004] [Indexed: 05/24/2023]
Abstract
We report collective ferromagnetic behavior with high Curie temperatures (T(c)) in Fe dot assemblies supported by the Cu(111) surface. Our ability to tune the average size and spacing of the individual dots allows us to conclude that enhanced magnetic anisotropy cannot account for this high-T(c) ferromagnetic order. Because our Monte Carlo simulations have ruled out the dipolar interaction as the dominant factor in this system, we attribute the origin of the ferromagnetic order to indirect exchange coupling via the Cu(111) substrate.
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Affiliation(s)
- J P Pierce
- Condensed Matter Sciences Division, Oak Ridge National Laboratory, and Department of Physics and Astronomy, The University of Tennessee, Knoxville, USA
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12
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Farnan GA, Fu CL, Gai Z, Krcmar M, Baddorf AP, Zhang Z, Shen J. Electronic stability of magnetic Fe/Co superlattices with monatomic layer alternation. Phys Rev Lett 2003; 91:226106. [PMID: 14683255 DOI: 10.1103/physrevlett.91.226106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2003] [Indexed: 05/24/2023]
Abstract
We report a surprising observation that the growth of the [Fe(1 ML)/Co(1 ML)](n) superlattice of L1(0) structure on Cu(100) is stable only up to six atomic layers (n=3), which cannot be rationalized by stress arguments. Instead, first-principles calculations reveal a transition from the L1(0) to the B2 structure due to the effect of dimensionality on the stability of the electronic structure of the superlattice. Whereas the majority-spin electrons are energetically insensitive to the layer thickness, the minority-spin electrons induce the transition at n=3.
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Affiliation(s)
- G A Farnan
- Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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Gai Z, Ji H, Gao B, Zhao RG, Yang WS. Surface structure of the (3 x 1) and (3 x 2) reconstructions of Ge(113). Phys Rev B Condens Matter 1996; 54:8593-8599. [PMID: 9984536 DOI: 10.1103/physrevb.54.8593] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Gai Z, Yu H, Yang WS. Adatom diffusion on Ge(111) and the corresponding activation energy barrier. Phys Rev B Condens Matter 1996; 53:13547-13550. [PMID: 9983101 DOI: 10.1103/physrevb.53.13547] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Gai Z, Zhao RG, He Y, Ji H, Hu C, Yang WS. Chemisorption of group-III metals on the (111) surface of group-IV semiconductors: In/Ge(111). Phys Rev B Condens Matter 1996; 53:1539-1547. [PMID: 9983617 DOI: 10.1103/physrevb.53.1539] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Gai Z, He Y, Yu H, Yang WS. Observation of conductance quantization of ballistic metallic point contacts at room temperature. Phys Rev B Condens Matter 1996; 53:1042-1045. [PMID: 9983550 DOI: 10.1103/physrevb.53.1042] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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