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Dima D, Jiang D, Singh DJ, Hasipek M, Shah HS, Ullah F, Khouri J, Maciejewski JP, Jha BK. Multiple Myeloma Therapy: Emerging Trends and Challenges. Cancers (Basel) 2022; 14:cancers14174082. [PMID: 36077618 PMCID: PMC9454959 DOI: 10.3390/cancers14174082] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/16/2022] [Accepted: 08/18/2022] [Indexed: 11/16/2022] Open
Abstract
Multiple myeloma (MM) is a complex hematologic malignancy characterized by the uncontrolled proliferation of clonal plasma cells in the bone marrow that secrete large amounts of immunoglobulins and other non-functional proteins. Despite decades of progress and several landmark therapeutic advancements, MM remains incurable in most cases. Standard of care frontline therapies have limited durable efficacy, with the majority of patients eventually relapsing, either early or later. Induced drug resistance via up-modulations of signaling cascades that circumvent the effect of drugs and the emergence of genetically heterogeneous sub-clones are the major causes of the relapsed-refractory state of MM. Cytopenias from cumulative treatment toxicity and disease refractoriness limit therapeutic options, hence creating an urgent need for innovative approaches effective against highly heterogeneous myeloma cell populations. Here, we present a comprehensive overview of the current and future treatment paradigm of MM, and highlight the gaps in therapeutic translations of recent advances in targeted therapy and immunotherapy. We also discuss the therapeutic potential of emerging preclinical research in multiple myeloma.
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Affiliation(s)
- Danai Dima
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Center for Immunotherapy and Precision Immuno-Oncology, Lerner Research Institute, Cleveland, OH 44195, USA
- Department of Hematology and Medical Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Dongxu Jiang
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Center for Immunotherapy and Precision Immuno-Oncology, Lerner Research Institute, Cleveland, OH 44195, USA
| | - Divya Jyoti Singh
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Center for Immunotherapy and Precision Immuno-Oncology, Lerner Research Institute, Cleveland, OH 44195, USA
| | - Metis Hasipek
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Haikoo S. Shah
- Department of Hematology and Medical Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Fauzia Ullah
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Jack Khouri
- Department of Hematology and Medical Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106, USA
- Cleveland Clinic Lerner College of Medicine, Cleveland, OH 44195, USA
| | - Jaroslaw P. Maciejewski
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106, USA
- Cleveland Clinic Lerner College of Medicine, Cleveland, OH 44195, USA
| | - Babal K. Jha
- Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Center for Immunotherapy and Precision Immuno-Oncology, Lerner Research Institute, Cleveland, OH 44195, USA
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106, USA
- Cleveland Clinic Lerner College of Medicine, Cleveland, OH 44195, USA
- Correspondence:
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Sun JP, Ye GZ, Shahi P, Yan JQ, Matsuura K, Kontani H, Zhang GM, Zhou Q, Sales BC, Shibauchi T, Uwatoko Y, Singh DJ, Cheng JG. High-T_{c} Superconductivity in FeSe at High Pressure: Dominant Hole Carriers and Enhanced Spin Fluctuations. Phys Rev Lett 2017; 118:147004. [PMID: 28430492 DOI: 10.1103/physrevlett.118.147004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Indexed: 06/07/2023]
Abstract
The importance of electron-hole interband interactions is widely acknowledged for iron-pnictide superconductors with high transition temperatures (T_{c}). However, the absence of hole pockets near the Fermi level of the iron-selenide (FeSe) derived high-T_{c} superconductors raises a fundamental question of whether iron pnictides and chalcogenides have different pairing mechanisms. Here, we study the properties of electronic structure in the high-T_{c} phase induced by pressure in bulk FeSe from magnetotransport measurements and first-principles calculations. With increasing pressure, the low-T_{c} superconducting phase transforms into the high-T_{c} phase, where we find the normal-state Hall resistivity changes sign from negative to positive, demonstrating dominant hole carriers in contrast to other FeSe-derived high-T_{c} systems. Moreover, the Hall coefficient is enlarged and the magnetoresistance exhibits anomalous scaling behaviors, evidencing strongly enhanced interband spin fluctuations in the high-T_{c} phase. These results in FeSe highlight similarities with high-T_{c} phases of iron pnictides, constituting a step toward a unified understanding of iron-based superconductivity.
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Affiliation(s)
- J P Sun
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - G Z Ye
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Science and Astronomy, Yunnan University, Kunming 650091, China
| | - P Shahi
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - J-Q Yan
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - K Matsuura
- Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| | - H Kontani
- Department of Physics, Nagoya University, Furo-cho, Nagoya 464-8602, Japan
| | - G M Zhang
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
| | - Q Zhou
- School of Physical Science and Astronomy, Yunnan University, Kunming 650091, China
| | - B C Sales
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - T Shibauchi
- Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba 277-8561, Japan
| | - Y Uwatoko
- The Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - D J Singh
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211-7010, USA
| | - J-G Cheng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
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Singh DJ, Singh VK, Singh DK. Photomediated Larvicidal Activity of Pheophorbide a against Cercaria Larvae of Fasciola gigantica. Scientifica (Cairo) 2017; 2017:5219194. [PMID: 28127494 PMCID: PMC5239984 DOI: 10.1155/2017/5219194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 12/14/2016] [Indexed: 06/06/2023]
Abstract
Fasciolosis is a parasitic disease caused by Fasciola gigantica. The freshwater snail Lymnaea acuminata is the intermediate host of F. gigantica which cause endemic fasciolosis in the northern part of India. To investigate larvicidal activity of pure and laboratory extracted pheophorbide a (Pa) against cercaria larvae of F. gigantica, data were analyzed in different spectra of visible light, sunlight, and laboratory conditions. Photostimulation of chlorophyll derivative pheophorbide a (Pa) caused time and concentration dependent larvicidal activity against cercaria larvae of F. gigantica. Larvicidal activity of pure Pa under 650 nm and 400-650 nm (8 h LC50 0.006 mg/10 mL) was more pronounced than extracted Pa under same irradiations (650 nm LC50 0.12 mg/10 mL, 400-650 nm LC50 0.14 mg/10 mL). Lowest toxicity of pure (8 h LC50 0.14 mg/10 mL) and extracted Pa (8 h LC50 1.25 mg/10 mL) was noted under 400 nm. Pa was found to be toxic in laboratory conditions also. The results presented in this paper indicate that pheophorbide a possess potential larvicidal activity against Fasciola gigantica larvae in different wavelengths of visible light, sunlight, and laboratory conditions.
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Affiliation(s)
- Divya Jyoti Singh
- Malacology Laboratory, Department of Zoology, D.D.U. Gorakhpur University, Gorakhpur, Uttar Pradesh 273 009, India
| | - Vinay Kumar Singh
- Malacology Laboratory, Department of Zoology, D.D.U. Gorakhpur University, Gorakhpur, Uttar Pradesh 273 009, India
| | - D. K. Singh
- Malacology Laboratory, Department of Zoology, D.D.U. Gorakhpur University, Gorakhpur, Uttar Pradesh 273 009, India
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Poudel L, May AF, Koehler MR, McGuire MA, Mukhopadhyay S, Calder S, Baumbach RE, Mukherjee R, Sapkota D, de la Cruz C, Singh DJ, Mandrus D, Christianson AD. Candidate Elastic Quantum Critical Point in LaCu_{6-x}Au_{x}. Phys Rev Lett 2016; 117:235701. [PMID: 27982606 DOI: 10.1103/physrevlett.117.235701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Indexed: 06/06/2023]
Abstract
The structural properties of LaCu_{6-x}Au_{x} are studied using neutron diffraction, x-ray diffraction, and heat capacity measurements. The continuous orthorhombic-monoclinic structural phase transition in LaCu_{6} is suppressed linearly with Au substitution until a complete suppression of the structural phase transition occurs at the critical composition x_{c}=0.3. Heat capacity measurements at low temperatures indicate residual structural instability at x_{c}. The instability is ferroelastic in nature, with density functional theory calculations showing negligible coupling to electronic states near the Fermi level. The data and calculations presented here are consistent with the zero temperature termination of a continuous structural phase transition suggesting that the LaCu_{6-x}Au_{x} series hosts an elastic quantum critical point.
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Affiliation(s)
- L Poudel
- Department of Physics & Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - A F May
- Materials Science & Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - M R Koehler
- Department of Material Science & Engineering, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - M A McGuire
- Materials Science & Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - S Mukhopadhyay
- Materials Science & Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - S Calder
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - R E Baumbach
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA
| | - R Mukherjee
- Department of Material Science & Engineering, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - D Sapkota
- Department of Physics & Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - C de la Cruz
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - D J Singh
- Department of Physics & Astronomy, University of Missouri, Columbia, Missouri 65211, USA
| | - D Mandrus
- Department of Physics & Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
- Materials Science & Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Material Science & Engineering, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A D Christianson
- Department of Physics & Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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Morrow R, Taylor AE, Singh DJ, Xiong J, Rodan S, Wolter AUB, Wurmehl S, Büchner B, Stone MB, Kolesnikov AI, Aczel AA, Christianson AD, Woodward PM. Spin-orbit coupling control of anisotropy, ground state and frustration in 5d(2) Sr2MgOsO6. Sci Rep 2016; 6:32462. [PMID: 27571715 PMCID: PMC5004149 DOI: 10.1038/srep32462] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 08/05/2016] [Indexed: 11/09/2022] Open
Abstract
The influence of spin-orbit coupling (SOC) on the physical properties of the 5d2 system Sr2MgOsO6 is probed via a combination of magnetometry, specific heat measurements, elastic and inelastic neutron scattering, and density functional theory calculations. Although a significant degree of frustration is expected, we find that Sr2MgOsO6 orders in a type I antiferromagnetic structure at the remarkably high temperature of 108 K. The measurements presented allow for the first accurate quantification of the size of the magnetic moment in a 5d2 system of 0.60(2) μB –a significantly reduced moment from the expected value for such a system. Furthermore, significant anisotropy is identified via a spin excitation gap, and we confirm by first principles calculations that SOC not only provides the magnetocrystalline anisotropy, but also plays a crucial role in determining both the ground state magnetic order and the size of the local moment in this compound. Through comparison to Sr2ScOsO6, it is demonstrated that SOC-induced anisotropy has the ability to relieve frustration in 5d2 systems relative to their 5d3 counterparts, providing an explanation of the high TN found in Sr2MgOsO6.
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Affiliation(s)
- Ryan Morrow
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210-1185, USA
| | - Alice E Taylor
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - D J Singh
- Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211-7010, USA
| | - Jie Xiong
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210-1185, USA
| | - Steven Rodan
- Leibniz Institute for Solid State and Materials Research Dresden IFW, D-01171 Dresden, Germany
| | - A U B Wolter
- Leibniz Institute for Solid State and Materials Research Dresden IFW, D-01171 Dresden, Germany
| | - Sabine Wurmehl
- Leibniz Institute for Solid State and Materials Research Dresden IFW, D-01171 Dresden, Germany.,Institute for Solid State Physics, Technische Universität Dresden, D-01062 Dresden, Germany
| | - Bernd Büchner
- Leibniz Institute for Solid State and Materials Research Dresden IFW, D-01171 Dresden, Germany.,Institute for Solid State Physics, Technische Universität Dresden, D-01062 Dresden, Germany
| | - M B Stone
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - A I Kolesnikov
- Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Adam A Aczel
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - A D Christianson
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.,Department of Physics and Astronomy, The University of Tennessee, Knoxville, TN 37996, USA
| | - Patrick M Woodward
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210-1185, USA
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Singh DJ, Singh DK. ANTHELMINTIC ACTIVITY OF CHLOROPHYLLIN AGAINST DIFFERENT LARVAL STAGES OF Fasciola gigantica. Rev Inst Med Trop Sao Paulo 2016; 58:39. [PMID: 27253741 PMCID: PMC4879996 DOI: 10.1590/s1678-9946201658039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Accepted: 11/23/2015] [Indexed: 01/04/2023] Open
Abstract
Fasciolosis is a food borne zoonosis, caused by the digenetic trematode
Fasciola. Freshwater lymnaeid snails are the intermediate host of
the trematodes. Chlorophyllin, a semi-synthetic derivative of chlorophyll and its
formulations obtained from freeze dried cow urine (FCU) had their toxicity tested
against redia and cercaria larvae of F. gigantica. The larvicidal
activity of chlorophyllin and its formulations were found to depend on both, time and
concentration used against the larvae. Toxicity of chlorophyllin + FCU (1:1 ratio) in
sunlight against redia larva (8 h LC50: 0.03 mg/mL) was more pronounced
than using just chlorophyllin (8 h LC50: 0.06 mg/mL). Toxicity of
chlorophyllin + FCU in sunlight against redia (8 h LC50: 0.03 mg/mL) was
higher than against cercaria (8 h LC50: 0.06 mg/mL). The larvicidal
activity of chlorophyllin in sunlight (redia/cercaria larvae: 8 h LC50:
0.06 mg/mL) was more pronounced than under laboratory conditions (redia: 8 h
LC50: 22.21 mg/mL/, cercaria 8 h LC50: 96.21 mg/mL).
Toxicity of FCU against both larvae was lower than that of chlorophyllin and
chlorophyllin + FCU. Chlorophyllin and its formulations + FCU were 357.4 to 1603.5
times more effective against redia/cercaria larvae in sunlight than under laboratory
conditions. The present study has shown that chlorophyllin formulations may be used
as potent larvicides against fasciolosis.
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Singh DJ, Singh DK. Phytotherapy of chlorophyllin exposed Lymnaea acuminata: A new biotechnological tool for fasciolosis control. Parasite Epidemiol Control 2016; 1:20-25. [PMID: 29988195 PMCID: PMC5991855 DOI: 10.1016/j.parepi.2016.03.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 03/17/2016] [Accepted: 03/17/2016] [Indexed: 01/20/2023] Open
Abstract
Phytotherapy of chlorophyllin formulations against Fasciola gigantica infected Lymnaea acuminata under sunlight exposure was highly toxic against redia and cercaria larvae. Binary combinations (1:1 ratio) of chlorophyllin (CHL) + freeze dried cow urine (FCU) were more toxic against cercariae (8 h LC50: 9.6 mg L- 1) than single treatment with chlorophyllin (8 h LC50: 12.6 mg L- 1) in sunlight. The larvicidal activity of sunlight exposed CHL against rediae (8 h LC50: 13.5 mg L- 1) and cercariae (8 h LC50: 12.6 mg L- 1) was more pronounced than laboratory conditions CHL treatment (rediae- 8 h LC50: 305.9 mg L- 1; cercariae- 8 h LC50: 765.4 mg L- 1). Larvicidal activity of FCU was less than CHL and CHL + FCU against both redia and cercaria. Chlorophyllin and its formulations were more toxic against redia and cercaria larvae in sunlight than laboratory conditions. CHL and its different formulations may be used as potent larvicides against Fasciola gigantica larvae. Chlorophyllin formulations will be economical, ecologically sounder and their use in aquatic environment will be safe.
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Affiliation(s)
- Divya Jyoti Singh
- Malacology Laboratory, Department of Zoology, D.D.U. Gorakhpur University, Gorakhpur, Uttar Pradesh, Pin: 273 009, India
| | - D K Singh
- Malacology Laboratory, Department of Zoology, D.D.U. Gorakhpur University, Gorakhpur, Uttar Pradesh, Pin: 273 009, India
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Cao G, Singh DJ, Zhang XG, Samolyuk G, Qiao L, Parish C, Jin K, Zhang Y, Guo H, Tang S, Wang W, Yi J, Cantoni C, Siemons W, Payzant EA, Biegalski M, Ward TZ, Mandrus D, Stocks GM, Gai Z. Ferromagnetism and nonmetallic transport of thin-film α-FeSi(2): a stabilized metastable material. Phys Rev Lett 2015; 114:147202. [PMID: 25910157 DOI: 10.1103/physrevlett.114.147202] [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] [Received: 09/01/2014] [Indexed: 06/04/2023]
Abstract
A metastable phase α-FeSi_{2} was epitaxially stabilized on a silicon substrate using pulsed laser deposition. Nonmetallic and ferromagnetic behaviors are tailored on α-FeSi_{2} (111) thin films, while the bulk material of α-FeSi_{2} is metallic and nonmagnetic. The transport property of the films renders two different conducting states with a strong crossover at 50 K, which is accompanied by the onset of a ferromagnetic transition as well as a substantial magnetoresistance. These experimental results are discussed in terms of the unusual electronic structure of α-FeSi_{2} obtained within density functional calculations and Boltzmann transport calculations with and without strain. Our finding sheds light on achieving ferromagnetic semiconductors through both their structure and doping tailoring, and provides an example of a tailored material with rich functionalities for both basic research and practical applications.
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Affiliation(s)
- Guixin Cao
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - D J Singh
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056, USA
| | - X-G Zhang
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - German Samolyuk
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056, USA
| | - Liang Qiao
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Chad Parish
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056, USA
| | - Ke Jin
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Yanwen Zhang
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056, USA
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Hangwen Guo
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056, USA
| | - Siwei Tang
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Wenbin Wang
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056, USA
| | - Jieyu Yi
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Claudia Cantoni
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056, USA
| | - Wolter Siemons
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056, USA
| | - E Andrew Payzant
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Michael Biegalski
- 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 37831-6056, USA
| | - David Mandrus
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056, USA
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - G M Stocks
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056, USA
| | - Zheng Gai
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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Singh DJ, Singh DK. Toxicity of chlorophyllin in different wavelengths of visible light against Fasciola gigantica larvae. J Photochem Photobiol B 2015; 144:57-60. [PMID: 25720554 DOI: 10.1016/j.jphotobiol.2015.01.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 01/13/2015] [Accepted: 01/27/2015] [Indexed: 06/04/2023]
Abstract
Toxicity of chlorophyllin against redia and cercaria larvae of Fasciola gigantica was studied under irradiation of visible light. Highest and lowest toxicity of chlorophyllin against both larvae was noted under red (redia - 8 h LC₅₀ 7.88 mg/10 mL and cercaria - 11.99 mg/10 mL) and green (redia - 8 h LC₅₀ 32.12 mg/10 mL and cercaria - 8 h LC₅₀ 43.80 mg/10 mL) light irradiation respectively. The highest toxicity of chlorophyllin under red light irradiation against redia (8h LC₅₀ 7.88 mg/10 mL)/cercaria (8h LC₅₀ 11.99 mg/10 mL) was followed by white (8 h LC₅₀ redia - 20.48 mg/10 mL, 8 h LC₅₀ cercaria - 18.0 3mg/10 mL), blue (8 h LC₅₀ redia - 33.10 mg/10 mL/ 8 h LC₅₀ cercaria - 19.98 mg/10 mL) and yellow (8 h LC₅₀ redia - 23.87 mg/10 mL/ 8 h LC₅₀ cercaria - 23.48 mg/10 mL). Chlorophyllin treatment in darkness (control I) and without treatment of chlorophyllin, while all other conditions were same as treatment group (control II) caused no mortality of redia/cercaria larva. Chlorophyllin might be a promising new safe strategy to replace synthetic larvicide in fasciolosis control programme.
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Affiliation(s)
- Divya Jyoti Singh
- Malacology Laboratory, Department of Zoology, DDU Gorakhpur University, Gorakhpur, U.P., India
| | - D K Singh
- Malacology Laboratory, Department of Zoology, DDU Gorakhpur University, Gorakhpur, U.P., India.
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10
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Li CW, Hellman O, Ma J, May AF, Cao HB, Chen X, Christianson AD, Ehlers G, Singh DJ, Sales BC, Delaire O. Phonon self-energy and origin of anomalous neutron scattering spectra in SnTe and PbTe thermoelectrics. Phys Rev Lett 2014; 112:175501. [PMID: 24836255 DOI: 10.1103/physrevlett.112.175501] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Indexed: 05/02/2023]
Abstract
The anharmonic lattice dynamics of rock-salt thermoelectric compounds SnTe and PbTe are investigated with inelastic neutron scattering (INS) and first-principles calculations. The experiments show that, surprisingly, although SnTe is closer to the ferroelectric instability, phonon spectra in PbTe exhibit a more anharmonic character. This behavior is reproduced in first-principles calculations of the temperature-dependent phonon self-energy. Our simulations reveal how the nesting of phonon dispersions induces prominent features in the self-energy, which account for the measured INS spectra and their temperature dependence. We establish that the phase space for three-phonon scattering processes, combined with the proximity to the lattice instability, is the mechanism determining the complex spectrum of the transverse-optic ferroelectric mode.
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Affiliation(s)
- C W Li
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - O Hellman
- Department of Physics, Chemistry and Biology, Linköping University, Linköping SE-581 83, Sweden
| | - J Ma
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - A F May
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - H B Cao
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - X Chen
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - A D Christianson
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - G Ehlers
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - D J Singh
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - B C Sales
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - O Delaire
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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11
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Singh DJ, Lohade AA, Parmar JJ, Hegde DD, Soni P, Samad A, Menon MD. Development of Chitosan-based Dry Powder Inhalation System of Cisplatin for Lung Cancer. Indian J Pharm Sci 2013; 74:521-6. [PMID: 23798777 PMCID: PMC3687921 DOI: 10.4103/0250-474x.110584] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Revised: 11/18/2012] [Accepted: 11/27/2012] [Indexed: 11/08/2022] Open
Abstract
Cisplatin, a platinum compound, exerts its cytotoxic effects by coordinating to DNA where it inhibits both replication and transcription, and induces programmed cell death. It is used in the treatment of non-small cell lung cancer. In the present study, an attempt was made to achieve better treatment of lung cancer by direct lung delivery of cisplatin microparticulate systems, which helps to localize the drug in the lungs, and also provide sustained action. Cisplatin-loaded chitosan microspheres were prepared by emulsification and ionotropic gelation method, and characterized for drug content, particle size, densities, flow properties, moisture content, and surface topography by SEM and in vitro drug release was evaluated in simulated lung fluid at 37° at pH 7.4. The respirable or fine particle fraction (FPF) was determined by using twin stage impinger (TSI). Further stability evaluation of cisplatin-loaded DPI systems was carried out at 25°/60% RH and at 40°/75% RH.
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Affiliation(s)
- D J Singh
- Department of Pharmaceutics, Bombay College of Pharmacy, Kalina, Santacruz (E), Mumbai-400 098, India
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12
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Parmar JJ, Singh DJ, Lohade AA, Hegde DD, Soni PS, Samad A, Menon MD. Inhalational system for Etoposide liposomes: formulation development and in vitro deposition. Indian J Pharm Sci 2012; 73:656-62. [PMID: 23112400 PMCID: PMC3480751 DOI: 10.4103/0250-474x.100240] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Revised: 12/16/2011] [Accepted: 12/25/2011] [Indexed: 11/04/2022] Open
Abstract
Etoposide is a semisynthetic compound, widely used in treatment of non small cell lung cancer. However, frequent dosing and adverse effects remain a major concern in the use of etoposide. Liposomal systems for pulmonary drug delivery have been particularly attractive because of their compatibility with lung surfactant components. In the present investigation, pulmonary liposomal delivery system of etoposide was prepared by film hydration method. Various parameters were optimized with respect to entrapment efficiency as well as particle size of etoposide liposomes. For better shelf life of etoposide liposomes, freeze drying using trehalose as cryoprotectant was carried out. The liposomes were characterized for entrapment efficiency, particle size, surface topography, and in vitro drug release was carried out in simulated lung fluid at 37° at pH 7.4. The respirable or fine particle fraction was determined by using twin stage impinger. The stability study of freeze dried as well as aqueous liposomal systems was carried out at 2-8° and at ambient temperature (28±4°). The freeze dried liposomes showed better fine particle fraction and drug content over the period of six months at ambient as well as at 2-8° storage condition compared to aqueous dispersion of liposomes.
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Affiliation(s)
- J J Parmar
- Bombay College of Pharmacy, Kalina, Santacruz (E), Mumbai-400 098, India
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13
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Biswas K, Du MH, T-Thienprasert J, Limpijumnong S, Singh DJ. Comment on "Uncovering the complex behavior of hydrogen in Cu2O". Phys Rev Lett 2012; 108:219703-219704. [PMID: 23003317 DOI: 10.1103/physrevlett.108.219703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Indexed: 06/01/2023]
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14
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Stone MB, Lumsden MD, Nagler SE, Singh DJ, He J, Sales BC, Mandrus D. Quasi-one-dimensional magnons in an intermetallic marcasite. Phys Rev Lett 2012; 108:167202. [PMID: 22680752 DOI: 10.1103/physrevlett.108.167202] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 01/30/2012] [Indexed: 06/01/2023]
Abstract
We present inelastic neutron scattering measurements and first principles calculations examining the intermetallic marcasite CrSb(2). The observed spin-wave dispersion implies that the magnetic interactions are strongly one-dimensional with antiferromagnetic chains parallel to the crystalline c axis. Such low-dimensional excitations are unexpected in a semiconducting intermetallic system. Moreover, we observe a clear anisotropic thermal conductivity indicating that the magnetic anisotropy enhances thermoelectric properties along particular crystallographic directions.
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Affiliation(s)
- M B Stone
- Neutron Sciences Directorate, Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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15
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Dunsiger SR, Aczel AA, Arguello C, Dabkowska H, Dabkowski A, Du MH, Goko T, Javanparast B, Lin T, Ning FL, Noad HML, Singh DJ, Williams TJ, Uemura YJ, Gingras MJP, Luke GM. Spin ice: magnetic excitations without monopole signatures using muon spin rotation. Phys Rev Lett 2011; 107:207207. [PMID: 22181768 DOI: 10.1103/physrevlett.107.207207] [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: 08/04/2011] [Indexed: 05/31/2023]
Abstract
Theory predicts the low temperature magnetic excitations in spin ices consist of deconfined magnetic charges, or monopoles. A recent transverse-field (TF) muon spin rotation (μSR) experiment [S. T. Bramwell et al., Nature (London) 461, 956 (2009)] reports results claiming to be consistent with the temperature and magnetic field dependence anticipated for monopole nucleation-the so-called second Wien effect. We demonstrate via a new series of μSR experiments in Dy(2)Ti(2)O(7) that such an effect is not observable in a TF μSR experiment. Rather, as found in many highly frustrated magnetic materials, we observe spin fluctuations which become temperature independent at low temperatures, behavior which dominates over any possible signature of thermally nucleated monopole excitations.
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Affiliation(s)
- S R Dunsiger
- Physik Department, Technische Universität München, Garching, Germany.
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16
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Delaire O, Ma J, Marty K, May AF, McGuire MA, Du MH, Singh DJ, Podlesnyak A, Ehlers G, Lumsden MD, Sales BC. Giant anharmonic phonon scattering in PbTe. Nat Mater 2011; 10:614-9. [PMID: 21642983 DOI: 10.1038/nmat3035] [Citation(s) in RCA: 174] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 04/22/2011] [Indexed: 05/24/2023]
Abstract
Understanding the microscopic processes affecting the bulk thermal conductivity is crucial to develop more efficient thermoelectric materials. PbTe is currently one of the leading thermoelectric materials, largely thanks to its low thermal conductivity. However, the origin of this low thermal conductivity in a simple rocksalt structure has so far been elusive. Using a combination of inelastic neutron scattering measurements and first-principles computations of the phonons, we identify a strong anharmonic coupling between the ferroelectric transverse optic mode and the longitudinal acoustic modes in PbTe. This interaction extends over a large portion of reciprocal space, and directly affects the heat-carrying longitudinal acoustic phonons. The longitudinal acoustic-transverse optic anharmonic coupling is likely to play a central role in explaining the low thermal conductivity of PbTe. The present results provide a microscopic picture of why many good thermoelectric materials are found near a lattice instability of the ferroelectric type.
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Affiliation(s)
- O Delaire
- Neutron Scattering Science Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, USA.
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17
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18
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Zhang L, T-Thienprasert J, Du MH, Singh DJ, Limpijumnong S. Comment on "Spectroscopic signatures of novel oxygen-defect complexes in stoichiometrically controlled CdSe". Phys Rev Lett 2009; 102:209601-209602. [PMID: 19519081 DOI: 10.1103/physrevlett.102.209601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2009] [Indexed: 05/27/2023]
Affiliation(s)
- L Zhang
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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19
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Kurita N, Ronning F, Tokiwa Y, Bauer ED, Subedi A, Singh DJ, Thompson JD, Movshovich R. Low-temperature magnetothermal transport investigation of a Ni-based superconductor BaNi2As2: evidence for fully gapped superconductivity. Phys Rev Lett 2009; 102:147004. [PMID: 19392475 DOI: 10.1103/physrevlett.102.147004] [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: 11/17/2008] [Indexed: 05/27/2023]
Abstract
We have performed low-temperature specific heat and thermal conductivity measurements of the Ni-based superconductor BaNi2As2 (T{c}=0.7 K) in a magnetic field. In a zero field, thermal conductivity shows T-linear behavior in the normal state and exhibits a BCS-like exponential decrease below T{c}. The field dependence of the residual thermal conductivity extrapolated to zero temperature is indicative of a fully gapped superconductor. This conclusion is supported by the analysis of the specific heat data, which are well fit by the BCS temperature dependence from T{c} down to the lowest temperature of 0.1 K.
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Affiliation(s)
- N Kurita
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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20
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Bondino F, Magnano E, Malvestuto M, Parmigiani F, McGuire MA, Sefat AS, Sales BC, Jin R, Mandrus D, Plummer EW, Singh DJ, Mannella N. Evidence for strong itinerant spin fluctuations in the normal state of CeFeAsO0.89F0.11 iron-oxypnictide superconductors. Phys Rev Lett 2008; 101:267001. [PMID: 19113783 DOI: 10.1103/physrevlett.101.267001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2008] [Indexed: 05/27/2023]
Abstract
The electronic structure in the normal state of CeFeAsO0.89F0.11 oxypnictide superconductors has been investigated with x-ray absorption and photoemission spectroscopy. All of the data exhibit signatures of Fe d-electron itinerancy. Exchange multiplets appearing in the Fe 3s core level indicate the presence of itinerant spin fluctuations. These findings suggest that the underlying physics and the origin of superconductivity in these materials are likely to be quite different from those of the cuprate high-temperature superconductors. These materials provide opportunities for elucidating the role of magnetic fluctuations in high-temperature superconductivity.
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Affiliation(s)
- F Bondino
- CNR-INFM, Laboratorio Nazionale TASC, S.S. 14, km 163.5, 1-34012 Trieste, Italy
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21
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Mazin II, Singh DJ, Johannes MD, Du MH. Unconventional superconductivity with a sign reversal in the order parameter of LaFeAsO1-xFx. Phys Rev Lett 2008; 101:057003. [PMID: 18764420 DOI: 10.1103/physrevlett.101.057003] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Indexed: 05/15/2023]
Abstract
We argue that the newly discovered superconductivity in a nearly magnetic, Fe-based layered compound is unconventional and mediated by antiferromagnetic spin fluctuations, though different from the usual superexchange and specific to this compound. This resulting state is an example of extended s-wave pairing with a sign reversal of the order parameter between different Fermi surface sheets. The main role of doping in this scenario is to lower the density of states and suppress the pair-breaking ferromagnetic fluctuations.
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Affiliation(s)
- I I Mazin
- Code 6393, Naval Research Laboratory, Washington, D.C. 20375, USA
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22
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Tamai A, Allan MP, Mercure JF, Meevasana W, Dunkel R, Lu DH, Perry RS, Mackenzie AP, Singh DJ, Shen ZX, Baumberger F. Fermi surface and van Hove singularities in the itinerant Metamagnet Sr3Ru2O7. Phys Rev Lett 2008; 101:026407. [PMID: 18764208 DOI: 10.1103/physrevlett.101.026407] [Citation(s) in RCA: 7] [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] [Received: 03/06/2008] [Indexed: 05/26/2023]
Abstract
The low-energy electronic structure of the itinerant metamagnet Sr3Ru2O7 is investigated by angle-resolved photoemission and density-functional calculations. We find well-defined quasiparticle bands with resolution-limited linewidths and Fermi velocities up to an order of magnitude lower than in single layer Sr2RuO4. The complete topography, the cyclotron masses, and the orbital character of the Fermi surface are determined, in agreement with bulk sensitive de Haas-van Alphen measurements. An analysis of the dxy band dispersion reveals a complex density of states with van Hove singularities near the Fermi level, a situation which is favorable for magnetic instabilities.
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Affiliation(s)
- A Tamai
- Scottish Universities Physics Alliance, School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9SS, United Kingdom.
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23
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Singh DJ, Du MH. Density functional study of LaFeAsO(1-x)F(x): a low carrier density superconductor near itinerant magnetism. Phys Rev Lett 2008; 100:237003. [PMID: 18643537 DOI: 10.1103/physrevlett.100.237003] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Indexed: 05/15/2023]
Abstract
Density functional studies of 26 K superconducting LaFeAs(O,F) are reported. We find a low carrier density, high density of states, N(E(F)), and modest phonon frequencies relative to T(c). The high N(E(F)) leads to proximity to itinerant magnetism, with competing ferromagnetic and antiferromagnetic fluctuations and the balance between these controlled by the doping level. Thus LaFeAs(O,F) is in a unique class of high T(c) superconductors: high N(E(F)) ionic metals near magnetism.
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Affiliation(s)
- D J Singh
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6114, USA
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24
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Bultmark F, Dewhurst K, Singh DJ, Nordström L. Tests of the efficiency of an augmented distorted planewave basis in electronic structure calculations. J Phys Condens Matter 2008; 20:235241. [PMID: 21694331 DOI: 10.1088/0953-8984/20/23/235241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
An augmented distorted planewave plus local orbital basis set has been developed and implemented in a simple fashion in order to test its efficiency for electronic structure calculations. It is based on the idea of using distorted planewaves (Gygi 1993 Phys. Rev. B 48 11692) as basis functions in the interstitial region instead of ordinary planewaves, as in the usual linearized augmented planewave and augmented planewave plus local orbitals methods. This is shown to lead to a significantly more rapid convergence for open structures as well as a modestly improved convergence for close packed structures.
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Affiliation(s)
- F Bultmark
- Department of Physics, Uppsala University, Box 530, SE-751 21, Uppsala, Sweden
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25
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Singh DJ, Park CH. Polar behavior in a magnetic perovskite from a-site size disorder: a density functional study. Phys Rev Lett 2008; 100:087601. [PMID: 18352665 DOI: 10.1103/physrevlett.100.087601] [Citation(s) in RCA: 11] [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: 09/20/2007] [Indexed: 05/26/2023]
Abstract
We elucidate a mechanism for obtaining polar behavior in magnetic perovskites based on A-site disorder and demonstrate this mechanism by density functional calculations for the double perovskite (La,Lu)MnNiO6 with Lu concentrations at and below 50%. We show that this material combines polar behavior and ferromagnetism. The mechanism is quite general and may be applicable to a wide range of magnetic perovskites.
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Affiliation(s)
- D J Singh
- Materials Science and Technology Division, Oak Ridge, Tennessee 37831-6114, USA
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26
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Krishnamurthy VV, Lang JC, Haskel D, Keavney DJ, Srajer G, Robertson JL, Sales BC, Mandrus DG, Singh DJ, Bilc DI. Ferrimagnetism in EuFe4Sb12 due to the interplay of f-electron moments and a nearly ferromagnetic host. Phys Rev Lett 2007; 98:126403. [PMID: 17501140 DOI: 10.1103/physrevlett.98.126403] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2006] [Indexed: 05/15/2023]
Abstract
We combine x-ray magnetic circular dichroism spectroscopy at Fe L2,3 edges, at Eu M4,5 edges, x-ray absorption spectroscopy (XAS) investigation of Eu valence, and local spin density calculations, to show that the filled skutterudite Eu0.95Fe4Sb12 is a ferrimagnet in which the Fe 3d moment and the Eu2+ 4f moment are magnetically ordered with dominant antiferromagnetic coupling. From Eu L3 edge XAS, we find that about 13% of the Eu have a formal valence of 3+. We ascribe the origin of ferrimagnetism at a relatively high transition temperature TC of 85 K in Eu0.95Fe4Sb12 to f-electron interaction with the nearly ferromagnetic [Fe4Sb12]2.2- host lattice.
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Affiliation(s)
- V V Krishnamurthy
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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27
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Singh DJ, Kasinathan D. Destruction of the small Fermi surfaces in NaxCoO2 by disorder. Phys Rev Lett 2006; 97:016404. [PMID: 16907391 DOI: 10.1103/physrevlett.97.016404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2006] [Indexed: 05/11/2023]
Abstract
We show using density functional calculations that the small e'g Fermi surfaces in NaxCoO2 are destroyed by Na disorder. This provides a means to resolve the prediction of these sections in band structure calculations with their nonobservation in angle resolved photoemission experiments.
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Affiliation(s)
- D J Singh
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6032, USA
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28
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Baumberger F, Ingle NJC, Meevasana W, Shen KM, Lu DH, Perry RS, Mackenzie AP, Hussain Z, Singh DJ, Shen ZX. Fermi surface and quasiparticle excitations of Sr2RhO4. Phys Rev Lett 2006; 96:246402. [PMID: 16907260 DOI: 10.1103/physrevlett.96.246402] [Citation(s) in RCA: 3] [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: 12/30/2005] [Indexed: 05/11/2023]
Abstract
The electronic structure of the layered 4d transition metal oxide Sr2RhO4 is investigated by angle resolved photoemission. We find well-defined quasiparticle excitations with a highly anisotropic dispersion, suggesting a quasi-two-dimensional Fermi-liquid-like ground state. Markedly different from the isostructural Sr2RuO4, only two bands with dominant Rh 4dxz,zy character contribute to the Fermi surface. A quantitative analysis of the photoemission quasiparticle band structure is in excellent agreement with bulk data. In contrast, it is found that state-of-the-art density functional calculations in the local density approximation differ significantly from the experimental findings.
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Affiliation(s)
- F Baumberger
- Department of Applied Physics, and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, California 94305, USA
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29
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Bilc DI, Singh DJ. Frustration of tilts and A-site driven ferroelectricity in KNbO3-LiNbO3 alloys. Phys Rev Lett 2006; 96:147602. [PMID: 16712120 DOI: 10.1103/physrevlett.96.147602] [Citation(s) in RCA: 9] [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: 02/08/2006] [Revised: 03/07/2006] [Indexed: 05/09/2023]
Abstract
Density functional calculations for K(0.5)Li(0.5)NbO(3) show strong A-site driven ferroelectricity, even though the average tolerance factor is significantly smaller than unity and there is no stereochemically active A-site ion. This is due to the frustration of tilt instabilities by A-site disorder. There are very large off centerings of the Li ions, which contribute strongly to the anisotropy between the tetragonal and rhombohedral ferroelectric states, yielding a tetragonal ground state even without strain coupling.
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Affiliation(s)
- D I Bilc
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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30
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Abstract
Density functional calculations of the fermiology and magnetic properties of Ca3Ru2O7 reveal an unusual state: a bulk spin valve. The ground state consists of nearly half-metallic bilayers stacked antiferromagnetically with a weak coupling. Out of plane transport is very strongly suppressed by the antiferromagnetic alignment, which can be destroyed in favor of ferromagnetism at low energy cost. Furthermore, the spin transport in the ferromagnetic state is highly unusual; opposite sign spin polarizations are found for currents in plane and out of plane.
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Affiliation(s)
- D J Singh
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6032, USA
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31
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Balicas L, Nakatsuji S, Hall D, Ohnishi T, Fisk Z, Maeno Y, Singh DJ. Severe Fermi surface reconstruction at a metamagnetic transition in Ca2-xSrxRuO4 (for 0.2 <or=x<or=0.5). Phys Rev Lett 2005; 95:196407. [PMID: 16384006 DOI: 10.1103/physrevlett.95.196407] [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: 07/19/2005] [Indexed: 05/05/2023]
Abstract
We report an electrical transport study in Ca2-xSrxRuO4 single crystals at high magnetic fields (B). For x=0.2, the Hall constant Rxy decreases sharply at an anisotropic metamagnetic transition, reaching its value for Sr2RuO4 at high fields. A sharp decrease in the coefficient of the resistivity T2 term and a change in the structure of the angular magnetoresistance oscillations for B rotating in the planes confirms the reconstruction of the Fermi surface. Our observations and local-density-approximation calculations indicate a strong dependence of the Fermi surface on Ca concentration and suggest the coexistence of itinerant and localized electronic states in single layered ruthenates.
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Affiliation(s)
- L Balicas
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA
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32
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Blaha P, Singh DJ, Schwarz K. Geometric frustration, electronic instabilities, and charge singlets in Y2Nb2O7. Phys Rev Lett 2004; 93:216403. [PMID: 15601038 DOI: 10.1103/physrevlett.93.216403] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2004] [Indexed: 05/24/2023]
Abstract
Pyrochlore Y2Nb2O7 is studied with density functional calculations. In the ideal pyrochlore structure, no magnetism is found, consistent with experiments, but the band structure is metallic. The phonon dispersions show unstable modes corresponding to charge instabilities. These frustrated instabilities lead to a metal-insulator transition with the formation of "charge singlets". Partial substitution of Ti for Nb results in moment formation due to the occurrence of Ti3+.
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Affiliation(s)
- P Blaha
- Institute for Materials Chemistry, TU Wien, Getreidemarkt 9/165-TC, A-1060, Vienna, Austria
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33
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Johannes MD, Mazin II, Singh DJ, Papaconstantopoulos DA. Nesting, spin fluctuations, and odd-gap superconductivity in NaxCoO2.yH2O. Phys Rev Lett 2004; 93:097005. [PMID: 15447132 DOI: 10.1103/physrevlett.93.097005] [Citation(s) in RCA: 13] [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: 03/03/2004] [Indexed: 05/24/2023]
Abstract
We calculated the one-electron susceptibility of hydrated NaxCoO2 and find strong nesting, involving about 70% of all electrons at the Fermi level and nearly commensurate with a 2 x 2 superstructure. This nesting creates a tendency to a charge density wave compatible with the charge order often seen at x approximately 0.5 and usually ascribed to electrostatic repulsion of Na ions. In the spin channel, it leads to strong spin fluctuations, which should be important for superconductivity. The state most compatible with this nesting structure is an odd-gap triplet s-wave state.
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Affiliation(s)
- M D Johannes
- Code 6391, Naval Research Laboratory, Washington, DC 20375, USA
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34
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Aguayo A, Mazin II, Singh DJ. Why Ni3Al is an itinerant ferromagnet but Ni3Ga is not. Phys Rev Lett 2004; 92:147201. [PMID: 15089568 DOI: 10.1103/physrevlett.92.147201] [Citation(s) in RCA: 7] [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] [Received: 10/27/2003] [Revised: 10/31/2003] [Indexed: 05/24/2023]
Abstract
Ni3Al and Ni3Ga are closely related materials on opposite sides of a ferromagnetic quantum critical point. The Stoner factor of Ni is virtually the same in both compounds and the density of states is larger in Ni3Ga. Thus in Stoner theory it should be more magnetic, and in local-density approximation (LDA) calculations it is. However, experimentally it is a paramagnet, while Ni3Al is an itinerant ferromagnet. We show that critical spin fluctuations are stronger in Ni3Ga, due to weaker q dependence of the susceptibility, and this effect is enough to reverse the trend. The approach combines LDA calculations with Landau theory and the fluctuation-dissipation theorem using the same momentum cutoff for both compounds. The calculations provide evidence for strong, beyond LDA, spin fluctuations associated with the critical point in both materials, but stronger in Ni3Ga than in Ni3Al.
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Affiliation(s)
- A Aguayo
- Center for Computational Materials Science, Naval Research Laboratory, Washington, D.C. 20375, USA
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Sergienko IA, Keppens V, McGuire M, Jin R, He J, Curnoe SH, Sales BC, Blaha P, Singh DJ, Schwarz K, Mandrus D. Metallic "ferroelectricity" in the pyrochlore Cd2Re2O7. Phys Rev Lett 2004; 92:065501. [PMID: 14995250 DOI: 10.1103/physrevlett.92.065501] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2003] [Indexed: 05/24/2023]
Abstract
A class of materials known as "ferroelectric metals" was discussed theoretically by Anderson and Blount in 1965 [Phys. Rev. Lett. 14, 217 (1965)]], but to date no examples of this class of materials have been reported. Here we present measurements of the elastic moduli of Cd2Re2O7 through the 200 K cubic-to-tetragonal phase transition. A Landau analysis of the moduli reveals that the transition is consistent with Cd2Re2O7 being classified as a ferroelectric metal in the weaker sense described by Anderson and Blount (loss of a center of symmetry). First-principles calculations of the lattice instabilities indicate that the dominant lattice instability corresponds to a twofold degenerate mode with E(u) symmetry and that motions of the O ions forming the O octahedra dominate the energetics of the transition.
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Affiliation(s)
- I A Sergienko
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, Newfoundland, Canada A1B 3X7
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Abstract
It has long been suspected that spin fluctuations in ZrZn2 may lead to a triplet superconductivity. We point out another possibility, an inhomogeneous singlet (Fulde-Ferrell) state. We calculated the electronic structure, as well as the zone center phonons and their coupling with electrons. We find that the exchange splitting is nonuniform and the Fermi surface exhibits substantial nesting. Both factors favor a Fulde-Ferrell state at parts of the Fermi surface. We find a substantial coupling of Zr rattling modes with electrons, which can provide the necessary pairing in the s-channel.
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Affiliation(s)
- D J Singh
- Code 6390, Naval Research Laboratory, Washington, D.C. 20375, USA
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Dhillon SS, Singh DJ, Dass B, Schaub CR. Transitional cell carcinoma manifesting as acute cor pulmonale: cause of microscopic tumor embolism. South Med J 2001; 94:1030-2. [PMID: 11702817] [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: 02/22/2023]
Abstract
Acute cor pulmonale is an uncommon manifestation of microscopic pulmonary tumor embolism. We describe the case of an 84-year-old man with a history of transitional cell carcinoma (TCC) of the urinary bladder who had acute cor pulmonale and died within a few hours after the onset of dyspnea. Autopsy showed that the right ventricle was dilated without hypertrophy. Microscopic examination of the lung showed that the small arteries, arterioles, and capillaries were filled with micrometastases of TCC. Microscopic pulmonary tumor embolism has rarely been reported with TCC, and to the best of our knowledge, such a fulminant course has not been previously described in the English language.
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Affiliation(s)
- S S Dhillon
- Department of Internal Medicine , St Elizabeth Health Center, Youngstown, Ohio, USA
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Wong PM, Piamsomboon C, Mathur A, Chastain HD, Singh DJ, Liu MW, Parks JM, Iyer S, Dean LS, Baxley WA, Bourge RC, Roubin GS. Efficacy of coronary stenting in the management of cardiac allograft vasculopathy. Am J Cardiol 1998; 82:239-41. [PMID: 9678298 DOI: 10.1016/s0002-9149(98)00295-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We undertook a study to determine the efficacy of stents in reducing restenosis in cardiac allograft vasculopathy. The result shows that coronary stenting significantly reduces restenosis in cardiac allograft vasculopathy compared with balloon angioplasty alone.
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Affiliation(s)
- P M Wong
- Division of Cardiovascular Diseases, the University of Alabama at Birmingham, USA
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Singh DJ. Cryohaemorrhoidectomy for primary haemorrhoids: an evaluation of the procedure in the Indian population. J Indian Med Assoc 1998; 96:16-8. [PMID: 9601185] [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] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cryotherapy is one of the available modalities for the management of primary haemorrhoids. It is a simple non-invasive procedure conducted without anaesthesia, ideal for surgery outpatients' department. Though practically given up in the west due to a distressing side-effect in the local population, it was evaluated for its efficacy and acceptability in the Indian population. The study of 174 patients revealed the procedure to be well accepted, extremely cost effective and with a low complication rate in the Indian population, in contrast to the western experience.
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Affiliation(s)
- D J Singh
- Department of Surgery, Military Hospital, Jodhpur
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Singh DJ. STRESS FRACTURES OF THE FEMORAL SHAFT IN MILITARY RECRUITS. Med J Armed Forces India 1996; 52:239-241. [PMID: 28769404 DOI: 10.1016/s0377-1237(17)30875-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Stress fractures amongst military recruits are limited to the lower extremities; yet involvement of the shaft of the femur is unusual. Seven such cases in a series of 352 stress fractures are presented. The importance of early recognition and management is emphasized with a view to prevent bony disruption in an otherwise easily treatable condition.
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Affiliation(s)
- D J Singh
- Classified Specialist (Surgery), Military Hospital Jodhpur - 342010.,Military Hospital Roorkee
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Feldman JL, Singh DJ. Erratum: Lattice dynamics of skutterudites: First-principles and model calculations for CoSb3. Phys Rev B Condens Matter 1996; 54:712. [PMID: 9986980 DOI: 10.1103/physrevb.54.712.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Pickett WE, Singh DJ. Comment on "Density-functional description of the electronic structure of LaMO3 (M=Sc, Ti, V, Cr, Mn, Fe, Co, Ni)". Phys Rev B Condens Matter 1996; 53:7550. [PMID: 9982207 DOI: 10.1103/physrevb.53.7550] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Feldman JL, Singh DJ. Lattice dynamics of skutterudites: First-principles and model calculations for CoSb3. Phys Rev B Condens Matter 1996; 53:6273-6282. [PMID: 9982027 DOI: 10.1103/physrevb.53.6273] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [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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Pickett WE, Singh DJ. Electronic structure and half-metallic transport in the La1-xCaxMnO3 system. Phys Rev B Condens Matter 1996; 53:1146-1160. [PMID: 9983571 DOI: 10.1103/physrevb.53.1146] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.7] [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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Singh DJ. ACUTE ACALCULOUS CHOLECYSTITIS: Author's reply. Med J Armed Forces India 1995; 51:294. [PMID: 28769322 DOI: 10.1016/s0377-1237(17)31000-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- D J Singh
- Classified SpI (Surgery), Military Hospital Jodhpur
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