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Yavas B, Akram N, Frye A, Venkatesh V, Pilchak A, Furrer D, Cernatescu I, Aindow M. Evaluating the Dislocation Structures Involved in Dwell Fatigue Crack Initiation. Microsc Microanal 2023; 29:138-139. [PMID: 37613575 DOI: 10.1093/micmic/ozad067.062] [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] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- B Yavas
- Department of Materials Science and Engineering, Institute of Materials Science, University of Connecticut, Storrs, CT, USA
| | - N Akram
- Department of Materials Science and Engineering, Institute of Materials Science, University of Connecticut, Storrs, CT, USA
| | - A Frye
- Pratt & Whitney, East Harford, CT, USA
| | | | - A Pilchak
- Pratt & Whitney, East Harford, CT, USA
| | - D Furrer
- Pratt & Whitney, East Harford, CT, USA
| | | | - M Aindow
- Department of Materials Science and Engineering, Institute of Materials Science, University of Connecticut, Storrs, CT, USA
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Humayun A, Siddiqui FM, Akram N, Saleem S, Ali A, Iqbal T, Kumar A, Kamran R, Bokhari H. Incidence of metallo-beta-lactamase-producing Klebsiella pneumoniae isolates from hospital setting in Pakistan. Int Microbiol 2018; 21:73-78. [PMID: 30810920 DOI: 10.1007/s10123-018-0006-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 04/19/2018] [Accepted: 04/20/2018] [Indexed: 10/16/2022]
Abstract
The aim of this study was monitoring and surveillance in different wards of the PIMS hospital, Islamabad, to understand emerging challenges of antibiotic resistance in particular association with most virulent serotypes of Klebsiella pneumoniae. The study was conducted during March 2015 to September 2015. The study showed that rate of isolation of K. pneumoniae was 37% (103 positives out of a total of 277 clinical samples) and 7.7% (8) were phenotypically and genotypically confirmed to be metallo-β-lactamase resistant (carbapenem resistant) and all of them were multidrug resistant (MDR). These carbapenem-resistant isolates were isolated from blood, endotracheal tubes, and pus. Molecular screening for the presence of integrons indicated that distribution of class I integrons (87.5% of carbapenem-resistant K. pneumoniae isolates) was higher than class II integrons (1.25%) among given isolates. The study indicated that exposure of metallo-beta-lactamase-producing strains through hospitalizations increases the chances of spread of MDR pathogens. There is an urgent need for effective surveillance and monitoring strategies to control the spread of extremely resistant K. pneumoniae implicated in nosocomial infections leading to the increased health burden and enforcement of policy guideline on appropriate antibiotics usage.
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Affiliation(s)
- Aqsa Humayun
- Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan
| | - Fariha Masood Siddiqui
- Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan
| | - Neelam Akram
- Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan
| | - Sidra Saleem
- Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan
| | - Amjad Ali
- Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Tariq Iqbal
- PIMS Hospital, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Ashok Kumar
- PIMS Hospital, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Rubina Kamran
- PIMS Hospital, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Habib Bokhari
- Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan.
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Thulborn SJ, Akram N, Mistry V, Brightling CE, Moffitt K, Ribeiro D, Bafadhel M. S45 Evaluating the sensitivity and specificity of active neutrophil elastase as a biomarker for bacterial infection in subjects with copd. Thorax 2016. [DOI: 10.1136/thoraxjnl-2016-209333.51] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Akram N, Palovaara J, Forsberg J, Lindh MV, Milton DL, Luo H, González JM, Pinhassi J. Regulation of proteorhodopsin gene expression by nutrient limitation in the marine bacterium Vibrio sp. AND4. Environ Microbiol 2013; 15:1400-15. [PMID: 23379752 DOI: 10.1111/1462-2920.12085] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 01/08/2013] [Indexed: 01/21/2023]
Abstract
Proteorhodopsin (PR), a ubiquitous membrane photoprotein in marine environments, acts as a light-driven proton pump and can provide energy for bacterial cellular metabolism. However, knowledge of factors that regulate PR gene expression in different bacteria remains strongly limited. Here, experiments with Vibrio sp. AND4 showed that PR phototrophy promoted survival only in cells from stationary phase and not in actively growing cells. PR gene expression was tightly regulated, with very low values in exponential phase, a pronounced peak at the exponential/stationary phase intersection, and a marked decline in stationary phase. Thus, PR gene expression at the entry into stationary phase preceded, and could therefore largely explain, the stationary phase light-induced survival response in AND4. Further experiments revealed nutrient limitation, not light exposure, regulated this differential PR expression. Screening of available marine vibrios showed that the PR gene, and thus the potential for PR phototrophy, is found in at least three different clusters in the genus Vibrio. In an ecological context, our findings suggest that some PR-containing bacteria adapted to the exploitation of nutrient-rich micro-environments rely on a phase of relatively slowly declining resources to mount a cellular response preparing them for adverse conditions dispersed in the water column.
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Affiliation(s)
- Neelam Akram
- Centre for Ecology and Evolution in Microbial model Systems - EEMiS, Linnaeus University, SE-39182, Kalmar, Sweden
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Zhang HQ, Akram N, Skog P, Soroka IL, Trautmann C, Schuch R. Tailoring of keV-ion beams by image charge when transmitting through rhombic and rectangular shaped nanocapillaries. Phys Rev Lett 2012; 108:193202. [PMID: 23003038 DOI: 10.1103/physrevlett.108.193202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Indexed: 06/01/2023]
Abstract
We report on an unexpected effect of tailoring transmission profiles of Ne(7+) ions through nanocapillaries of rhombic and rectangular cross sections in mica. We find that capillaries of rhombic cross sections produce rectangular shaped ion transmission profiles and, vice versa, that capillaries of rectangular geometry give a rhombic beam shape. This shaping effect only occurs for transmitted ions and is absent for the small fraction of neutralized particles. The experimental findings and simulations of the projectile trajectories give clear evidence that the observed effect is due to the image forces experienced by the transmitting ions. This novel beam shaping mechanism suggests applications for the guiding, focusing, and shaping of ion beams.
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Affiliation(s)
- H-Q Zhang
- Physics Department, Stockholm University, S-106 91 Stockholm, Sweden
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Gómez-Consarnau L, Akram N, Lindell K, Pedersen A, Neutze R, Milton DL, González JM, Pinhassi J. Proteorhodopsin phototrophy promotes survival of marine bacteria during starvation. PLoS Biol 2010; 8:e1000358. [PMID: 20436956 PMCID: PMC2860489 DOI: 10.1371/journal.pbio.1000358] [Citation(s) in RCA: 145] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Accepted: 03/18/2010] [Indexed: 12/21/2022] Open
Abstract
Proteorhodopsins are globally abundant photoproteins found in bacteria in the photic zone of the ocean. Although their function as proton pumps with energy-yielding potential has been demonstrated, the ecological role of proteorhodopsins remains largely unexplored. Here, we report the presence and function of proteorhodopsin in a member of the widespread genus Vibrio, uncovered through whole-genome analysis. Phylogenetic analysis suggests that the Vibrio strain AND4 obtained proteorhodopsin through lateral gene transfer, which could have modified the ecology of this marine bacterium. We demonstrate an increased long-term survival of AND4 when starved in seawater exposed to light rather than held in darkness. Furthermore, mutational analysis provides the first direct evidence, to our knowledge, linking the proteorhodopsin gene and its biological function in marine bacteria. Thus, proteorhodopsin phototrophy confers a fitness advantage to marine bacteria, representing a novel mechanism for bacterioplankton to endure frequent periods of resource deprivation at the ocean's surface.
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Affiliation(s)
- Laura Gómez-Consarnau
- Marine Microbiology, School of Natural Sciences, Linnaeus University, Kalmar, Sweden
| | - Neelam Akram
- Marine Microbiology, School of Natural Sciences, Linnaeus University, Kalmar, Sweden
| | | | - Anders Pedersen
- Department of Chemistry, Biochemistry and Biophysics, Göteborg Gothenburg University, Göteborg, Sweden
| | - Richard Neutze
- Department of Chemistry, Biochemistry and Biophysics, Göteborg Gothenburg University, Göteborg, Sweden
| | - Debra L. Milton
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - José M. González
- Department of Microbiology and Cell Biology, University of La Laguna, La Laguna, Tenerife, Spain
| | - Jarone Pinhassi
- Marine Microbiology, School of Natural Sciences, Linnaeus University, Kalmar, Sweden
- * E-mail:
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Skog P, Zhang HQ, Akram N, Soroka IL, Trautmann C, Schuch R. Guiding of slow Ne7+-ions through insulating nano-capillaries of various geometrical cross-sections. ACTA ACUST UNITED AC 2009. [DOI: 10.1088/1742-6596/194/13/132030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Butt SB, Farhat W, Jan S, Ahmed S, Mohammad B, Akram N. Optimization of a Mobile Phase for Monitoring Strontium in Seawater Using Non‐suppressed Ion Chromatography. J LIQ CHROMATOGR R T 2009. [DOI: 10.1081/jlc-120037367] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- S. Bilal Butt
- a Central Analytical Facility Division , Pakistan Institute of Nuclear Science and Technology , P.O. Nilore, Islamabad , Pakistan
| | - W. Farhat
- a Central Analytical Facility Division , Pakistan Institute of Nuclear Science and Technology , P.O. Nilore, Islamabad , Pakistan
| | - S. Jan
- a Central Analytical Facility Division , Pakistan Institute of Nuclear Science and Technology , P.O. Nilore, Islamabad , Pakistan
| | - S. Ahmed
- a Central Analytical Facility Division , Pakistan Institute of Nuclear Science and Technology , P.O. Nilore, Islamabad , Pakistan
| | - B. Mohammad
- a Central Analytical Facility Division , Pakistan Institute of Nuclear Science and Technology , P.O. Nilore, Islamabad , Pakistan
| | - N. Akram
- a Central Analytical Facility Division , Pakistan Institute of Nuclear Science and Technology , P.O. Nilore, Islamabad , Pakistan
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