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Yadav RK, Govindaraj R, Vinod K, Sreepriya T, Mythili R. New insights into defects and magnetic interactions inducing lattice disordering in Co 2Fe 0.5Cr 0.5Al. RSC Adv 2023; 13:19106-19118. [PMID: 37362337 PMCID: PMC10288218 DOI: 10.1039/d2ra08318c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 05/31/2023] [Indexed: 06/28/2023] Open
Abstract
Atomic scale understanding of defect induced magnetic interactions resulting in lattice disordering has been deduced in a detailed manner for the first time in Co2Fe0.5Cr0.5Al based on Mössbauer spectroscopic studies and compared with the results obtained in Co2Fe0.8Cr0.2Al and Co2FeAl. An interesting linear correlation between valence electron concentration and the mean hyperfine fields at Fe sites in Co2FeAl based compounds has been deduced which is observed to exhibit different slopes with the substitution of Cr. This study elucidates an important role of the manifestation of the magnetic interactions especially between Fe, Co and Cr atoms leading to significant changes in the concentration and specific types of defects selectively produced in Co2Fe0.5Cr0.5Al as compared with that of Co2Fe0.8Cr0.2Al subjected to similar non-equilibrium treatments in this study. Further, for the first time this study elucidates the striking correlation of the effective value of the hyperfine field with the degree of ordering/disordering of the lattice with the Fe atoms associated with ordered sites experiencing a much higher value of the hyperfine field as compared to that of the disordered sites. This study also proposes optimal annealing treatment for the recovery of defects in Co2Fe0.5Cr0.5Al, which would be of significant importance in these spintronic materials.
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Affiliation(s)
- Ravi Kumar Yadav
- Materials Science Group, Indira Gandhi Centre for Atomic Research Kalpakkam 603102 Tamilnadu India
- Indira Gandhi Centre for Atomic Research, A CI of Homi Bhabha National Institute Kalpakkam 603102 Tamilnadu India
| | - R Govindaraj
- Materials Science Group, Indira Gandhi Centre for Atomic Research Kalpakkam 603102 Tamilnadu India
- Indira Gandhi Centre for Atomic Research, A CI of Homi Bhabha National Institute Kalpakkam 603102 Tamilnadu India
| | - K Vinod
- Materials Science Group, Indira Gandhi Centre for Atomic Research Kalpakkam 603102 Tamilnadu India
- Indira Gandhi Centre for Atomic Research, A CI of Homi Bhabha National Institute Kalpakkam 603102 Tamilnadu India
| | - T Sreepriya
- Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research Kalpakkam 603102 Tamilnadu India
- Indira Gandhi Centre for Atomic Research, A CI of Homi Bhabha National Institute Kalpakkam 603102 Tamilnadu India
| | - R Mythili
- Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research Kalpakkam 603102 Tamilnadu India
- Indira Gandhi Centre for Atomic Research, A CI of Homi Bhabha National Institute Kalpakkam 603102 Tamilnadu India
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Sakata Gurmesa G, Teshome T, Ermias Benti N, Ayalneh Tiruye G, Datta A, Setarge Mekonnen Y, Amente Geffe C. Rational Design of Biaxial Tensile Strain for Boosting Electronic and Ionic Conductivities of Na 2 MnSiO 4 for Rechargeable Sodium-Ion Batteries. Chemistry 2022; 11:e202100289. [PMID: 35678463 PMCID: PMC9179011 DOI: 10.1002/open.202100289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 05/10/2022] [Indexed: 11/22/2022]
Abstract
Using first‐principles calculations, biaxial tensile (ϵ=2 and 4 %) and compressive (ϵ=−2 and −4 %) straining of Na2MnSiO4 lattices resulted into radial distance cut offs of 1.65 and 2 Å, respectively, in the first and second nearest neighbors shell from the center. The Si−O and Mn−O bonds with prominent probability density peaks validated structural stability. Wide‐band gap of 2.35 (ϵ=0 %) and 2.54 eV (ϵ=−4 %), and narrow bandgap of 2.24 eV (ϵ=+4 %) estimated with stronger coupling of p–d σ bond than that of the p–d π bond, mainly contributed from the oxygen p‐state and manganese d‐state. Na+‐ion diffusivity was found to be enhanced by three orders of magnitude as the applied biaxial strain changed from compressive to tensile. According to the findings, the rational design of biaxial strain would improve the ionic and electronic conductivity of Na2MnSiO4 cathode materials for advanced rechargeable sodium‐ion batteries.
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Affiliation(s)
- Gamachis Sakata Gurmesa
- Department of Physics, College of Natural and Computational Sciences, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia.,Department of Physics, College of Natural and Computational Sciences, Addis Ababa University, P. O. Box 318, Mettu, Ethiopia
| | - Tamiru Teshome
- Department of Physics, College of Natural and Social Sciences, Addis Ababa Science and Technology University, P. O. Box 16417, Addis Ababa, Ethiopia
| | - Natei Ermias Benti
- Department of Physics, College of Natural and Computational Sciences, Wolaita Sodo University, P. O. Box 138, Wolaita Sodo, Ethiopia
| | - Girum Ayalneh Tiruye
- Materials Science Program/Department of Chemistry, College of Natural and Computational Sciences, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia
| | - Ayan Datta
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A and 2B, Raja S. C. Mullick Road, Jadavpur, Kolkata700032, West Bengal, India
| | - Yedilfana Setarge Mekonnen
- Center for Environmental Science, College of Natural and Computational Sciences, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia
| | - Chernet Amente Geffe
- Department of Physics, College of Natural and Computational Sciences, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia
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Ngo TD, Plé S, Thomas A, Barette C, Fortuné A, Bouzidi Y, Fauvarque MO, Pereira de Freitas R, Francisco Hilário F, Attrée I, Wong YS, Faudry E. Chimeric Protein-Protein Interface Inhibitors Allow Efficient Inhibition of Type III Secretion Machinery and Pseudomonas aeruginosa Virulence. ACS Infect Dis 2019; 5:1843-1854. [PMID: 31525902 DOI: 10.1021/acsinfecdis.9b00154] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen naturally resistant to many common antibiotics and acquires new resistance traits at an alarming pace. Targeting the bacterial virulence factors by an antivirulence strategy, therefore, represents a promising alternative approach besides antibiotic therapy. The Type III secretion system (T3SS) of P. aeruginosa is one of its main virulence factors. It consists of more than 20 proteins building a complex syringe-like machinery enabling the injection of toxin into host cells. Previous works showed that disrupting interactions between components of this machinery efficiently lowers the bacterial virulence. Using automated target-based screening of commercial and in-house libraries of small molecules, we identified compounds inhibiting the protein-protein interaction between PscE and PscG, the two cognate chaperones of the needle subunit PscF of P. aeruginosa T3SS. Two hits were selected and assembled using Split/Mix/Click chemistry to build larger hybrid analogues. Their efficacy and toxicity were evaluated using phenotypic analysis including automated microscopy and image analysis. Two nontoxic hybrid leads specifically inhibited the T3SS and reduced the ex vivo cytotoxicity of bacteria and their virulence in Galleria mellonella.
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Affiliation(s)
- Tuan-Dung Ngo
- Univ. Grenoble Alpes, CEA, INSERM, CNRS, Bacterial Pathogenesis and Cellular Responses, UMR 1036/ERL 5261, 17 avenue des Martyrs, Grenoble 38054, France
| | - Sophie Plé
- Univ. Grenoble Alpes, CNRS, Département de Pharmacochimie Moléculaire,
UMR 5063, ICMG FR 2607, 470 rue de la chimie, Grenoble 38000, France
- Univ. Grenoble Alpes, CEA, INSERM, CNRS, Bacterial Pathogenesis and Cellular Responses, UMR 1036/ERL 5261, 17 avenue des Martyrs, Grenoble 38054, France
| | - Aline Thomas
- Univ. Grenoble Alpes, CNRS, Département de Pharmacochimie Moléculaire,
UMR 5063, ICMG FR 2607, 470 rue de la chimie, Grenoble 38000, France
| | - Caroline Barette
- Univ. Grenoble Alpes, CEA, Inserm, IRIG, BGE, Genetics & Chemogenomics, 17 avenue des Martyrs, Grenoble 38054, France
| | - Antoine Fortuné
- Univ. Grenoble Alpes, CNRS, Département de Pharmacochimie Moléculaire,
UMR 5063, ICMG FR 2607, 470 rue de la chimie, Grenoble 38000, France
| | - Younes Bouzidi
- Univ. Grenoble Alpes, CNRS, Département de Pharmacochimie Moléculaire,
UMR 5063, ICMG FR 2607, 470 rue de la chimie, Grenoble 38000, France
| | - Marie-Odile Fauvarque
- Univ. Grenoble Alpes, CEA, Inserm, IRIG, BGE, Genetics & Chemogenomics, 17 avenue des Martyrs, Grenoble 38054, France
| | - Rossimiriam Pereira de Freitas
- Universidade Federal de Minas Gerais, Departamento de Química, UFMG, Av Pres Antônio Carlos, 6627, Pampulha, Belo Horizonte, Minas Gerais 31270-901, Brazil
| | - Flaviane Francisco Hilário
- Universidade Federal de Ouro Preto, Departamento de Química, ICEB, Campus Universitário Morro do Cruzeiro, Ouro Preto, Minas Gerais 35400-000, Brazil
| | - Ina Attrée
- Univ. Grenoble Alpes, CEA, INSERM, CNRS, Bacterial Pathogenesis and Cellular Responses, UMR 1036/ERL 5261, 17 avenue des Martyrs, Grenoble 38054, France
| | - Yung-Sing Wong
- Univ. Grenoble Alpes, CNRS, Département de Pharmacochimie Moléculaire,
UMR 5063, ICMG FR 2607, 470 rue de la chimie, Grenoble 38000, France
| | - Eric Faudry
- Univ. Grenoble Alpes, CEA, INSERM, CNRS, Bacterial Pathogenesis and Cellular Responses, UMR 1036/ERL 5261, 17 avenue des Martyrs, Grenoble 38054, France
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Induction of Necrosis in Human Macrophage Cell Lines by Corynebacterium diphtheriae and Corynebacterium ulcerans Strains Isolated from Fatal Cases of Systemic Infections. Int J Mol Sci 2019; 20:ijms20174109. [PMID: 31443569 PMCID: PMC6747468 DOI: 10.3390/ijms20174109] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/20/2019] [Accepted: 08/20/2019] [Indexed: 01/10/2023] Open
Abstract
When infecting a human host, Corynebacterium diphtheriae and Corynebacterium ulcerans are able to impair macrophage maturation and induce cell death. However, the underlying molecular mechanisms are not well understood. As a framework for this project, a combination of fluorescence microscopy, cytotoxicity assays, live cell imaging, and fluorescence-activated cell sorting was applied to understand the pathogenicity of two Corynebacterium strains isolated from fatal cases of systemic infections. The results showed a clear cytotoxic effect of the bacteria. The observed survival of the pathogens in macrophages and, subsequent, necrotic lysis of cells may be mechanisms explaining dissemination of C. diphtheriae and C. ulcerans to distant organs in the body.
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Guijarro JA, García-Torrico AI, Cascales D, Méndez J. The Infection Process of Yersinia ruckeri: Reviewing the Pieces of the Jigsaw Puzzle. Front Cell Infect Microbiol 2018; 8:218. [PMID: 29998086 PMCID: PMC6028603 DOI: 10.3389/fcimb.2018.00218] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 06/08/2018] [Indexed: 12/20/2022] Open
Abstract
Finding the keys to understanding the infectious process of Yersinia ruckeri was not a priority for many years due to the prompt development of an effective biotype 1 vaccine which was used mainly in Europe and USA. However, the gradual emergence of outbreaks in vaccinated fish, which have been reported since 2003, has awakened interest in the mechanism of virulence in this pathogen. Thus, during the last two decades, a large number of studies have considerably enriched our knowledge of many aspects of the pathogen and its interaction with the host. By means of both conventional and a variety of novel strategies, such as cell GFP tagging, bioluminescence imaging and optical projection tomography, it has been possible to determine three putative Y. ruckeri infection routes, the main point of entry for the bacterium being the gill lamellae. Moreover, a wide range of potential virulence factors have been highlighted by specific gene mutagenesis strategies or genome-wide transposon/plasmid insertion-based screening approaches, such us in vivo expression technology (IVET) and signature tagged mutagenesis (STM). Finally, recent proteomic and whole genomic analyses have allowed many of the genes and systems that are potentially implicated in the organism's pathogenicity and its adaptation to the host environmental conditions to be elucidated. Altogether, these studies contribute to a better understanding of the infectious process of Y. ruckeri in fish, which is crucial for the development of more effective strategies for preventing or treating enteric redmouth disease (ERM).
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Affiliation(s)
- José A Guijarro
- Área de Microbiología, Departamento de Biología Funcional, Facultad de Medicina, Instituto de Biotecnología de Asturias (IUBA), Universidad de Oviedo, Oviedo, Spain
| | - Ana I García-Torrico
- Área de Microbiología, Departamento de Biología Funcional, Facultad de Medicina, Instituto de Biotecnología de Asturias (IUBA), Universidad de Oviedo, Oviedo, Spain
| | - Desirée Cascales
- Área de Microbiología, Departamento de Biología Funcional, Facultad de Medicina, Instituto de Biotecnología de Asturias (IUBA), Universidad de Oviedo, Oviedo, Spain
| | - Jessica Méndez
- Área de Microbiología, Departamento de Biología Funcional, Facultad de Medicina, Instituto de Biotecnología de Asturias (IUBA), Universidad de Oviedo, Oviedo, Spain
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