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Goodacre S, Sutton L, Ennis K, Thomas B, Hawksworth O, Iftikhar K, Croft SJ, Fuller G, Waterhouse S, Hind D, Stevenson M, Bradburn MJ, Smyth M, Perkins GD, Millins M, Rosser A, Dickson J, Wilson M. Prehospital early warning scores for adults with suspected sepsis: the PHEWS observational cohort and decision-analytic modelling study. Health Technol Assess 2024; 28:1-93. [PMID: 38551135 PMCID: PMC11017155 DOI: 10.3310/ndty2403] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/02/2024] Open
Abstract
Background Guidelines for sepsis recommend treating those at highest risk within 1 hour. The emergency care system can only achieve this if sepsis is recognised and prioritised. Ambulance services can use prehospital early warning scores alongside paramedic diagnostic impression to prioritise patients for treatment or early assessment in the emergency department. Objectives To determine the accuracy, impact and cost-effectiveness of using early warning scores alongside paramedic diagnostic impression to identify sepsis requiring urgent treatment. Design Retrospective diagnostic cohort study and decision-analytic modelling of operational consequences and cost-effectiveness. Setting Two ambulance services and four acute hospitals in England. Participants Adults transported to hospital by emergency ambulance, excluding episodes with injury, mental health problems, cardiac arrest, direct transfer to specialist services, or no vital signs recorded. Interventions Twenty-one early warning scores used alongside paramedic diagnostic impression, categorised as sepsis, infection, non-specific presentation, or other specific presentation. Main outcome measures Proportion of cases prioritised at the four hospitals; diagnostic accuracy for the sepsis-3 definition of sepsis and receiving urgent treatment (primary reference standard); daily number of cases with and without sepsis prioritised at a large and a small hospital; the minimum treatment effect associated with prioritisation at which each strategy would be cost-effective, compared to no prioritisation, assuming willingness to pay £20,000 per quality-adjusted life-year gained. Results Data from 95,022 episodes involving 71,204 patients across four hospitals showed that most early warning scores operating at their pre-specified thresholds would prioritise more than 10% of cases when applied to non-specific attendances or all attendances. Data from 12,870 episodes at one hospital identified 348 (2.7%) with the primary reference standard. The National Early Warning Score, version 2 (NEWS2), had the highest area under the receiver operating characteristic curve when applied only to patients with a paramedic diagnostic impression of sepsis or infection (0.756, 95% confidence interval 0.729 to 0.783) or sepsis alone (0.655, 95% confidence interval 0.63 to 0.68). None of the strategies provided high sensitivity (> 0.8) with acceptable positive predictive value (> 0.15). NEWS2 provided combinations of sensitivity and specificity that were similar or superior to all other early warning scores. Applying NEWS2 to paramedic diagnostic impression of sepsis or infection with thresholds of > 4, > 6 and > 8 respectively provided sensitivities and positive predictive values (95% confidence interval) of 0.522 (0.469 to 0.574) and 0.216 (0.189 to 0.245), 0.447 (0.395 to 0.499) and 0.274 (0.239 to 0.313), and 0.314 (0.268 to 0.365) and 0.333 (confidence interval 0.284 to 0.386). The mortality relative risk reduction from prioritisation at which each strategy would be cost-effective exceeded 0.975 for all strategies analysed. Limitations We estimated accuracy using a sample of older patients at one hospital. Reliable evidence was not available to estimate the effectiveness of prioritisation in the decision-analytic modelling. Conclusions No strategy is ideal but using NEWS2, in patients with a paramedic diagnostic impression of infection or sepsis could identify one-third to half of sepsis cases without prioritising unmanageable numbers. No other score provided clearly superior accuracy to NEWS2. Research is needed to develop better definition, diagnosis and treatments for sepsis. Study registration This study is registered as Research Registry (reference: researchregistry5268). Funding This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 17/136/10) and is published in full in Health Technology Assessment; Vol. 28, No. 16. See the NIHR Funding and Awards website for further award information.
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Affiliation(s)
- Steve Goodacre
- School of Health and Related Research (ScHARR), University of Sheffield, Sheffield, UK
- Emergency Department, Northern General Hospital, Sheffield, UK
| | - Laura Sutton
- School of Health and Related Research (ScHARR), University of Sheffield, Sheffield, UK
| | - Kate Ennis
- School of Health and Related Research (ScHARR), University of Sheffield, Sheffield, UK
| | - Ben Thomas
- School of Health and Related Research (ScHARR), University of Sheffield, Sheffield, UK
| | - Olivia Hawksworth
- School of Health and Related Research (ScHARR), University of Sheffield, Sheffield, UK
| | | | - Susan J Croft
- Emergency Department, Northern General Hospital, Sheffield, UK
| | - Gordon Fuller
- Emergency Department, Northern General Hospital, Sheffield, UK
| | - Simon Waterhouse
- School of Health and Related Research (ScHARR), University of Sheffield, Sheffield, UK
| | - Daniel Hind
- School of Health and Related Research (ScHARR), University of Sheffield, Sheffield, UK
| | - Matt Stevenson
- School of Health and Related Research (ScHARR), University of Sheffield, Sheffield, UK
| | - Mike J Bradburn
- School of Health and Related Research (ScHARR), University of Sheffield, Sheffield, UK
| | - Michael Smyth
- Warwick Clinical Trials Unit, University of Warwick, Coventry, UK
| | - Gavin D Perkins
- Warwick Clinical Trials Unit, University of Warwick, Coventry, UK
| | - Mark Millins
- Yorkshire Ambulance Service NHS Trust, Wakefield, UK
| | - Andy Rosser
- West Midlands Ambulance Service University NHS Foundation Trust, Midlands, UK
| | - Jon Dickson
- Academic Unit of Primary Medical Care, University of Sheffield, Sheffield, UK
| | - Matthew Wilson
- School of Health and Related Research (ScHARR), University of Sheffield, Sheffield, UK
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Goodacre S, Sutton L, Thomas B, Hawksworth O, Iftikhar K, Croft S, Fuller G, Waterhouse S, Hind D, Bradburn M, Smyth MA, Perkins GD, Millins M, Rosser A, Dickson JM, Wilson MJ. Prehospital early warning scores for adults with suspected sepsis: retrospective diagnostic cohort study. Emerg Med J 2023; 40:768-776. [PMID: 37673643 PMCID: PMC10646863 DOI: 10.1136/emermed-2023-213315] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/18/2023] [Indexed: 09/08/2023]
Abstract
BACKGROUND Ambulance services need to identify and prioritise patients with sepsis for early hospital assessment. We aimed to determine the accuracy of early warning scores alongside paramedic diagnostic impression to identify sepsis that required urgent treatment. METHODS We undertook a retrospective diagnostic cohort study involving adult emergency medical cases transported to Sheffield Teaching Hospitals ED by Yorkshire Ambulance Service in 2019. We used routine ambulance service data to calculate 21 early warning scores and categorise paramedic diagnostic impressions as sepsis, infection, non-specific presentation or other presentation. We linked cases to hospital records and identified those meeting the sepsis-3 definition who received urgent hospital treatment for sepsis (reference standard). Analysis determined the accuracy of strategies that combined early warning scores at varying thresholds for positivity with paramedic diagnostic impression. RESULTS We linked 12 870/24 955 (51.6%) cases and identified 348/12 870 (2.7%) with a positive reference standard. None of the strategies provided sensitivity greater than 0.80 with positive predictive value greater than 0.15. The area under the receiver operating characteristic curve for the National Early Warning Score, version 2 (NEWS2) applied to patients with a diagnostic impression of sepsis or infection was 0.756 (95% CI 0.729, 0.783). No other early warning score provided clearly superior accuracy to NEWS2. Paramedic impression of sepsis or infection had sensitivity of 0.572 (0.519, 0.623) and positive predictive value of 0.156 (0.137, 0.176). NEWS2 thresholds of >4, >6 and >8 applied to patients with a diagnostic impression of sepsis or infection, respectively, provided sensitivities and positive predictive values of 0.522 (0.469, 0.574) and 0.216 (0.189, 0.245), 0.447 (0.395, 0.499) and 0.274 (0.239, 0.313), and 0.314 (0.268, 0.365) and 0.333 (0.284, 0.386). CONCLUSION No strategy is ideal but using NEWS2 alongside paramedic diagnostic impression of infection or sepsis could identify one-third to half of sepsis cases without prioritising unmanageable numbers. No other score provided clearly superior accuracy to NEWS2. TRIAL REGISTRATION NUMBER researchregistry5268, https://www.researchregistry.com/browse-the-registry%23home/registrationdetails/5de7bbd97ca5b50015041c33/.
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Affiliation(s)
- Steve Goodacre
- Sheffield Centre for Health and Related Research (SCHARR), The University of Sheffield, Sheffield, UK
| | - Laura Sutton
- Sheffield Centre for Health and Related Research (SCHARR), The University of Sheffield, Sheffield, UK
| | - Ben Thomas
- Sheffield Centre for Health and Related Research (SCHARR), The University of Sheffield, Sheffield, UK
| | - Olivia Hawksworth
- Sheffield Centre for Health and Related Research (SCHARR), The University of Sheffield, Sheffield, UK
| | | | - Susan Croft
- Emergency Department, Northern General Hospital, Sheffield, UK
| | - Gordon Fuller
- Sheffield Centre for Health and Related Research (SCHARR), The University of Sheffield, Sheffield, UK
| | - Simon Waterhouse
- Sheffield Centre for Health and Related Research (SCHARR), The University of Sheffield, Sheffield, UK
| | - Daniel Hind
- Sheffield Centre for Health and Related Research (SCHARR), The University of Sheffield, Sheffield, UK
| | - Mike Bradburn
- Sheffield Centre for Health and Related Research (SCHARR), The University of Sheffield, Sheffield, UK
| | | | | | - Mark Millins
- Yorkshire Ambulance Service NHS Trust, Wakefield, UK
| | - Andy Rosser
- West Midlands Ambulance Service, West Midlands, UK
| | - Jon M Dickson
- Sheffield Centre for Health and Related Research (SCHARR), The University of Sheffield, Sheffield, UK
| | - Matthew Joseph Wilson
- Sheffield Centre for Health and Related Research (SCHARR), The University of Sheffield, Sheffield, UK
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Ali A, Ahmed Z, Rahisuddin, Iftikhar K. Pure red-light emitting europium based complexes as efficient UV light converters: synthesis, crystal structure and photoluminescence properties. Dalton Trans 2023; 52:14075-14087. [PMID: 37743694 DOI: 10.1039/d3dt01536j] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
This paper reports three new crystallographically characterized europium complexes with composition as follows: [Eu(fod)3(L1)] (1), [Eu(fod)3(L2)] (2) and [Eu(fod)3(L3)] (3) {L1 = benzimidazole (bzi), L2 = 4,7-diphenyl-1,10-phenanthroline (bath), L3 = 2-(2-pyridyl) benzimidazole (py-im) and fod = anion of 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedione (Hfod)}. The single crystal (SC) XRD analysis shows that complex 1 is seven-coordinated while complexes 2 and 3 are eight-coordinated with the geometrical structures of a mono-capped octahedron and a trigonal dodecahedron, respectively. The NMR spectra of the complexes validate the SC-XRD results in solution. The complexes are stable in solution as no dissociation of any ligand was observed in the NMR spectra of the complexes. The photophysical properties of the complexes in solution, solid state, and PMMA thin films were studied. The hypersensitive transition 5D0 → 7F2 dominates the emission spectra in all phases, showing the highly asymmetric environment around the Eu(III) ion. The bath ligand is found to be the best sensitizer of the Eu ion and hence complex 2 shows the strongest luminescence properties with the highest absolute quantum yield among the three complexes. The CIE coordinate analysis shows that pure red-luminescence is emitted by the Eu complexes in the solid state since the coordinates found in this phase are closer to the standard NTSC 1987 values. The optical band gaps were determined for the complexes and the observed values suggest that the complexes can have possible applications in the field of semiconductor materials.
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Affiliation(s)
- Asgar Ali
- Lanthanide Research Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi 110025, India.
| | - Zubair Ahmed
- Lanthanide Research Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi 110025, India.
- Department of Chemistry, School of Basic and Applied Sciences, Galgotias University, Greater Noida, India
| | - Rahisuddin
- Lanthanide Research Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi 110025, India.
| | - K Iftikhar
- Lanthanide Research Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi 110025, India.
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Ganaie AB, Iftikhar K. Structure, optical absorption and NIR-Photoluminescence of ternary Neodymium (III) complexes with fluorinated β-diketone and heterocyclic Lewis bases. J Mol Struct 2023. [DOI: 10.1016/j.molstruc.2022.134352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Bashir Ganaie A, Iftikhar K. Stoichiometrically controlled synthesis and comparative study of photoluminescence of seven and eight coordinate complexes of Sm3+, Eu3+ and Tb3+ based on 6,6,7,7,8,8,8- heptafluoro-2,2-dimethyl-3,5-octanedione (Hfod) and imidazole. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2021.113715] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Ahmed Z, Ali A, Iftikhar K. Structure elucidation by Sparkle/RM1, and solution behavior of lanthanideIII complexes: NMR, 4f‒4f absorption spectra and Photoluminescent properties. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2021.131480] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Ansari AA, Ganaie AB, Iftikhar K. Synthesis and 4f 4f absorption studies of tris(acetylacetonato)praseodymium(III) and holmium(III) complexes with imidazole and pyrazole in non-aqueous solvents. Structure elucidation by Sparkle / PM7. J Mol Struct 2019. [DOI: 10.1016/j.molstruc.2019.07.073] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Ilmi R, Ganaie AB, Iftikhar K. 1H NMR of paramagnetic Lanthanide(III) complexes of trifluoroacetylacetone and 2,2′-Bipyridyl and 4f-4f absorption studies. J Mol Struct 2018. [DOI: 10.1016/j.molstruc.2018.07.046] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Dar WA, Ahmed Z, Iftikhar K. Cool white light emission from the yellow and blue emission bands of the Dy(III) complex under UV-excitation. J Photochem Photobiol A Chem 2018. [DOI: 10.1016/j.jphotochem.2017.12.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Ilmi R, Iftikhar K. Photophysical properties of Lanthanide(III) 1,1,1-trifluoro-2,4-pentanedione complexes with 2,2′-Bipyridyl: An experimental and theoretical investigation. J Photochem Photobiol A Chem 2017. [DOI: 10.1016/j.jphotochem.2016.10.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Dar WA, Iftikhar K. Phase controlled colour tuning of samarium and europium complexes and excellent photostability of their PVA encapsulated materials. Structural elucidation, photophysical parameters and the energy transfer mechanism in the Eu3+ complex by Sparkle/PM3 calculations. Dalton Trans 2016; 45:8956-71. [DOI: 10.1039/c6dt00549g] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Luminescence and photostability of new Sm and Eu complexes and those of their thin hybrid films have been investigated and discussed.
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Affiliation(s)
- Wakeel Ahmed Dar
- Lanthanide Research Laboratory
- Department of Chemistry
- Jamia Millia Islamia
- New Delhi 110 025
- India
| | - K. Iftikhar
- Lanthanide Research Laboratory
- Department of Chemistry
- Jamia Millia Islamia
- New Delhi 110 025
- India
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Ahmed Z, Iftikhar K. Efficient photoluminescent complexes of 400–1800 nm wavelength emitting lanthanides containing organic sensitizers for optoelectronic devices. RSC Adv 2014. [DOI: 10.1039/c4ra11330f] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Ahmed Z, Iftikhar K. Sensitization of Visible and NIR Emitting Lanthanide(III) Ions in Noncentrosymmetric Complexes of Hexafluoroacetylacetone and Unsubstituted Monodentate Pyrazole. J Phys Chem A 2013; 117:11183-201. [DOI: 10.1021/jp403668j] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zubair Ahmed
- Lanthanide Research
Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi 110 025, India
| | - K. Iftikhar
- Lanthanide Research
Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi 110 025, India
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Irfanullah M, Iftikhar K. Synthesis and spectroscopic analysis of an extended series of hetero dinuclear complexes containing two different lanthanides in 1:1 stoichiometry. Inorganica Chim Acta 2013. [DOI: 10.1016/j.ica.2012.08.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Ahmed Z, Dar WA, Iftikhar K. Syntheses and spectroscopic studies of volatile low symmetry lanthanide(III) complexes with monodentate 1H-indazole and fluorinated β-diketone. J COORD CHEM 2012. [DOI: 10.1080/00958972.2012.723704] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Zubair Ahmed
- a Department of Chemistry , Lanthanide Research Laboratory , Jamia Millia Islamia, New Delhi-110 025 , India
| | - Wakeel Ahmed Dar
- a Department of Chemistry , Lanthanide Research Laboratory , Jamia Millia Islamia, New Delhi-110 025 , India
| | - K. Iftikhar
- a Department of Chemistry , Lanthanide Research Laboratory , Jamia Millia Islamia, New Delhi-110 025 , India
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Ilmi R, Iftikhar K. Luminescent nine-coordinate lanthanide complexes derived from fluorinated β-diketone and 2,4,6-tris(2-pyridyl)-1,3,5-triazine. J COORD CHEM 2012. [DOI: 10.1080/00958972.2011.649737] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Rashid Ilmi
- a Department of Chemistry , Jamia Millia Islamia , New Delhi 110 025 , India
| | - K. Iftikhar
- a Department of Chemistry , Jamia Millia Islamia , New Delhi 110 025 , India
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Irfanullah M, Iftikhar K. A comparative study of 1H NMR and sensitized visible light emission of an extended series of dinuclear lanthanide complexes. J Photochem Photobiol A Chem 2011. [DOI: 10.1016/j.jphotochem.2011.09.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Du Plessis J, Iftikhar K. A pain in the foot. Arch Emerg Med 2011; 28:818. [DOI: 10.1136/emj.2010.098921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Ilmi R, Iftikhar K. Synthesis, visible light absorption and luminescence of bipyrimidine bridged dinuclear lanthanide complexes of 2,4-pantanedione. INORG CHEM COMMUN 2010. [DOI: 10.1016/j.inoche.2010.09.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Irfanullah M, Iftikhar K. Pyrazine-bridged dinuclear complex formation by early lanthanides (LaIII, PrIII, NdIII and SmIII) containing bulky fluorinated β-diketonates. INORG CHEM COMMUN 2010. [DOI: 10.1016/j.inoche.2010.06.045] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Ahmed Z, Iftikhar K. Synthesis and visible light luminescence of mononuclear nine-coordinate lanthanide complexes with 2,4,6-tris(2-pyridyl)-1,3,5-triazine. INORG CHEM COMMUN 2010. [DOI: 10.1016/j.inoche.2010.07.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Ahmed Z, Iftikhar K. Solution studies of lanthanide (III) complexes based on 1,1,1,5,5,5-hexafluoro-2,4-pentanedione and 1,10-phenanthroline Part-I: Synthesis, 1H NMR, 4f–4f absorption and photoluminescence. Inorganica Chim Acta 2010. [DOI: 10.1016/j.ica.2010.04.040] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Irfanullah M, Iftikhar K. New hetero-dilanthanide complexes containing Ln1(fod)3 and Ln2(fod)3 fragments (Ln=Pr–Nd; Nd–Sm; Eu–Tb and Ho–Er) linked by bis-diimine bridging ligand. INORG CHEM COMMUN 2010. [DOI: 10.1016/j.inoche.2010.03.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Abstract
A case report is presented of an aortic dissection in a patient with Turner's syndrome that went undiagnosed. A thorough discussion of this fatal condition in this group of patients is included.
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Affiliation(s)
- B J Burgess
- Southend University Hospital, Westcliff-on-Sea, Essex, UK.
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Irfanullah M, Iftikhar K. New dinuclear lanthanide(III) complexes based on 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedione and 2,2′-bipyrimidine. INORG CHEM COMMUN 2009. [DOI: 10.1016/j.inoche.2009.01.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Ansari AA, Hussain HA, Iftikhar K. Optical absorption spectroscopic studies on holmium(III) complexes with beta-diketone and heterocyclic amines: the environment effect on 4f-4f hypersensitive transitions. Spectrochim Acta A Mol Biomol Spectrosc 2007; 68:1305-12. [PMID: 17419092 DOI: 10.1016/j.saa.2007.02.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2006] [Revised: 01/15/2007] [Accepted: 02/08/2007] [Indexed: 05/14/2023]
Abstract
The optical absorption spectra of [Ho(acac)(3)(H(2)O)(2)].H(2)O, [Ho(acac)(3)phen] and [Ho(acac)(3)bpy] (where acac is the anion of acetylacetone; phen is 1,10-phenanthroline and bpy is 2,2'-bipyridyl) complexes in the visible region, in a series of non-aqueous solvents (methanol, ethanol, isopropanol, chloroform, acetonitrile and pyridine.) have been analyzed. The largest intensity variation was observed in the (5)G(6)<--(5)I(8) (centered at 450 nm), and (5)G(5), (3)H(5), (3)H(6)<--(5)I(8) (centered at 360 nm) transition regions. The band shape and oscillator strength of the hypersensitive transitions display pronounced changes as compared to Ho(3+) aqua-ion. The band shapes of the hypersensitive transitions show remarkable changes on passing from aqueous solution to various non-aqueous solutions which is the result of change in the environment about the Ho(III) ion in the various solutions and suggests coordination of solvent molecule(s), in some cases. The results clearly show that among the solvents studied pyridine is the most effective in promoting the 4f-4f spectral intensity. It has been inferred from this study that 2,2'-bipyridyl is a stronger ligand for heavier lanthanides. A comparative account of hypersensitivity in the present complexes with those of other adducts of Ho(beta-diketoenolate)(3) with heterocyclic amines is discussed. The TGA analyses showed that the phen complex is thermally more stable over its bpy analogue.
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Affiliation(s)
- A A Ansari
- Department of Chemistry, Jamia Millia Islamia, New Delhi, India
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Ansari AA, Ahmed Z, Iftikhar K. Nuclear magnetic resonance and optical absorption spectroscopic studies on paramagnetic praseodymium(III) complexes with beta-diketone and heterocyclic amines. Spectrochim Acta A Mol Biomol Spectrosc 2007; 68:176-83. [PMID: 17267279 DOI: 10.1016/j.saa.2006.11.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Revised: 11/14/2006] [Accepted: 11/15/2006] [Indexed: 05/13/2023]
Abstract
The optical absorption spectra of [Pr(acac)(3)(H(2)O)(2)].H(2)O, [Pr(acac)(3)phen.H(2)O] and [Pr(acac)(3)bpy] (where acac is the anion of acetylacetone, phen is 1,10-phenanthroline and bpy is 2,2'-bipyridyl) have been analyzed in the visible region in a series of non-aqueous solvents (methanol, ethanol, isopropanol, chloroform, acetonitrile and pyridine). The complexes display four non-hypersensitive 4f-4f transitions ((3)P(2), (3)P(1)+(1)I(6), (3)P(0) and (1)D(2)) from the (3)H(4) ground state. The band shape of the transitions shows remarkable changes upon dissolving in different solvents. Distinctively different band shapes have been observed for phen and bpy complexes. The phen is more effective in producing changes and the splitting of the bands is more pronounced in phen complex since it is a stronger ligand and leads to stronger Pr-N(phen) bond. The splitting of the bands is indicative of partaking of f-orbitals in bonding. The NMR signals of heterocyclic amines have been shifted to high fields while the resonances due to acetylacetone moiety have moved to low fields which is the consequence of change in geometry of the complexes upon coordination of the heterocyclic amines and reflects the importance of geometric factor (3cos(2)theta-1) in changing sign of the shift and to a good approximation the shifts arise predominantly from the dipolar mechanism. The phen complexes have narrower line width than bpy complexes. The line broadening in the case of bpy complexes is suggestive of exchange between inter-converting forms. The bpy possesses some degree of rotational freedom about C(6)-C(6') bond and the two pyridine rings undergo scissoring motion with respect to each other.
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Affiliation(s)
- A A Ansari
- Department of Chemistry, Jamia Millia Islamia, New Delhi 110025, India
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Ansari AA, Irfanullah M, Iftikhar K. Optical absorption and NMR spectroscopic studies on paramagnetic neodymium(III) complexes with beta-diketone and heterocyclic amines. The environment effect on 4f-4f hypersensitive transitions. Spectrochim Acta A Mol Biomol Spectrosc 2007; 67:1178-88. [PMID: 17158088 DOI: 10.1016/j.saa.2006.10.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Revised: 09/28/2006] [Accepted: 10/05/2006] [Indexed: 05/12/2023]
Abstract
The optical absorption spectra of [Nd(acac)3(H2O)2].H2O, [Nd(acac)3bpy] and [Nd(acac)3phen(H2O)2] (where acac=acetylacetone, bpy=2,2'-bipyridyl and phen=1,10-phenanthroline) complexes in the visible region, in a series of non-aqueous solvents (methanol, ethanol, isopropanol, chloroform, acetonitrile, pyridine, nitrobenzene and dimethylsulphoxide) have been analyzed. The transition 4G(5/2)<--4I(9/2) (Nd-VI) located near the middle of the visible region (17,500 cm(-1)) is hypersensitive. Its behavior is in sharp contrast to many other typically weak and consistently unvaried, normal 4f-4f transitions. The oscillator strength of this transition for the chelate as well as its adducts with phen and bpy in any of the solvent employed is larger than the oscillator strength of Nd3+ aqua-ion. It is most intense in pyridine for all the complexes studied and, therefore, pyridine is the most effective in promoting f-f spectral intensity. The band shape and oscillator strength of the hypersensitive transitions display pronounced changes as compared to Nd3+ aqua-ion. The band shapes of the hypersensitive transitions show remarkable changes on passing from aqueous solution to various non-aqueous solutions, which is the result of change in the environment about the Nd(III) ion in the various solutions and suggests change in the environment about the Nd(III) ion in the various solutions and suggests coordination of solvent molecule(s), in some cases. A comparative account of hypersensitivity in the present complexes with those of other adducts of Nd(beta-diketoenolate)3 with heterocyclic amines is discussed. The NMR signals of heterocyclic amines have been shifted to high fields while the resonances due to acetylacetone moiety have moved to low fields. The paramagnetic shift in the complexes is dipolar in nature.
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Affiliation(s)
- A A Ansari
- Department of Chemistry, Jamia Millia Islamia, New Delhi 110025, India
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Ali SM, Iftikhar K, Ahmad N. Schiff Base Complexes of Transition Metal Ions - IIa. Complexes ofp-Dimethylaminobenzaldehyde-1,3-propanediamine. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/00945718408058284] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Khan AA, Hussain HA, Iftikhar K. 4f-4f absorption spectra and hypersensitivity in nine-coordinate Ho(III) and Er(III) complexes in different environments. Spectrochim Acta A Mol Biomol Spectrosc 2004; 60:2087-2092. [PMID: 15248990 DOI: 10.1016/j.saa.2003.10.042] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2003] [Accepted: 10/30/2003] [Indexed: 05/24/2023]
Abstract
The effect of change in the environment upon 4f-4f absorption spectra of nine-coordinate Ho(III) and Er(III) complexes with thiocyanate and 2,2'-bipyridyl in methanol, DMSO, DMF and pyridine have been investigated. The oscillator strength for hypersensitive and non-hypersensitive transitions have been calculated and variation in the intensity and band shape with respect to solvent type is rationalized in terms of solvent structure and coordinating properties. A comparison with 1,10-phenanthroline complexes is investigated and has been found that phen has a larger impact on the transition intensities for these ions. Pyridine has been found most effective in promoting 4f-4f intensity. The results indicate that it is important to consider both the static and dynamic coupling mechanism while analysing the oscillator strength of hypersensitive transition.
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Affiliation(s)
- Azad A Khan
- Department of Chemistry, Jamia Millia Islamia, New Delhi 110025, India
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Hussain HA, Ansari AA, Iftikhar K. Optical absorption and NMR spectroscopic studies on paramagnetic trivalent lanthanide complexes with 2,2'-bipyridine.; The solvent effect on 4f-4f hypersensitive transitions. Spectrochim Acta A Mol Biomol Spectrosc 2004; 60:873-884. [PMID: 15036098 DOI: 10.1016/s1386-1425(03)00312-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2002] [Revised: 07/02/2003] [Accepted: 07/02/2003] [Indexed: 05/24/2023]
Abstract
The optical absorption and NMR studies of trivalent lanthanide chloride complexes with 2,2'-bipyridine (bpy) are presented and discussed. The NMR spectra of paramagnetic complexes exhibit lower as well as higher field shifts of bpy resonances that reflect change in geometry and reveals importance of the factor (3 cos2 theta - 1 ) in changing sign of the shift. The paramagnetic shifts recorded have been analyzed and the intramolecular shift ratios suggest that the paramagnetic shift is predominantly dipolar in origin. Electronic spectral studies of the Pr, Nd, Ho, Er and Dy complexes in different solvents (viz. methanol, pyridine, DMSO and DMF), which differ with respect to donor atoms, reveal that the chemical environment around the lanthanide ion has great impact on f-f transitions and any change in the environment results in modifications of the spectra. The oscillator strength for the hypersensitive and non-hypersensitive transitions have been determined and changes in the oscillator strength and band shape with respect to solvent type is rationalized in terms of ligand (solvent) structure and coordination properties.
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Affiliation(s)
- H A Hussain
- Department of Chemistry, Jamia Millia Islamia, New Delhi 110025, India
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Hussain HA, Iftikhar K. 4f-4f hypersensitivity in the absorption spectra and NMR studies on paramagnetic lanthanide chloride complexes with 1,10-phenanthroline in non-aqueous solutions. Spectrochim Acta A Mol Biomol Spectrosc 2003; 59:1061-1074. [PMID: 12633723 DOI: 10.1016/s1386-1425(02)00278-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The optical absorption and NMR studies of trivalent lanthanide chloride complexes with 1,10-phenanthroline (phen) are presented and discussed. The 1H NMR spectra of the complexes of La, Pr, Nd, Eu and Yb have been studied in methanol-d(4). The resonances of phen in the NMR spectra of the paramagnetic complexes have been shifted to lower as well as higher fields, which is a manifestation of dipolar interaction. The H (2) protons of the heterocyclic amine display broad resonances. The degree of broadening in Pr, Nd, and Yb complexes follows the order Pr < Nd < Yb. The inter- and intra-molecular shift ratios show that the paramagnetic shift is predominantly due to dipolar interaction. The electronic spectra of Pr, Nd, Ho and Er complexes have been investigated in methanol, pyridine, DMSO and DMF, which reveal that the hypersensitive transitions exhibit larger variation in oscillator strength values and band shapes. The change in the coordination geometry of the complexes and relative basicity of ligand are found responsible for oscillator strength and band shape variation. The interelectronic repulsion and covalency parameters show covalent nature of bonding between the metal and the ligand.
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Affiliation(s)
- H A Hussain
- Department of Chemistry, Jamia Millia Islamia, New Delhi 110 025, India
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Khan AA, Hussain HA, Iftikhar K. 4f-4f absorption spectra of nine-coordinate Pr (III) and Nd (III) complexes in different environments. Spectrochim Acta A Mol Biomol Spectrosc 2003; 59:1051-1059. [PMID: 12633722 DOI: 10.1016/s1386-1425(02)00277-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Absorption spectroscopic studies on the mixed-ligand complexes of Pr (III) and Nd (III) with 2,2'-bipyridyl and thiocyanate in pyridine, DMSO, DMF and methanol are presented. The oscillator strengths for the hypersensitive and non-hypersensitive transitions have been calculated and variation in the oscillator strength and band shapes with respect to solvent type is rationalized in terms of solvent structures and coordinating properties. A comparison is made with 1,10-phenanthroline complexes and has been shown that bpy is a weaker ligand than phen for these ions. Pyridine has been found most effective in promoting 4f-4f intensity and the increase in the oscillator strength in this solvent is due to dynamic ligand polarization mechanism.
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Affiliation(s)
- Azad A Khan
- Department of Chemistry, Jamia Millia Islamia, New Delhi 110 025, India
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Iftikhar K, Sayeed M, Ahmad N. Mixed-ligand complexes of trivalent lanthanide ions with .beta.-diketones and heterocyclic amines. Inorg Chem 2002. [DOI: 10.1021/ic00131a015] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Khan AA, Iftikhar K. Mixed-ligand lanthanide complexes—XI. Absorption spectra and hypersensitivity in the complexes of PrIII, NdIII, HoIII and ErIII in nonaqueous solutions. Polyhedron 1997. [DOI: 10.1016/s0277-5387(97)00138-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Khan AA, Saxena AK, Iftikhar K. Mixed-ligand lanthanide complexes—X. Interaction of trivalent lanthanides with 1,10-phenanthroline and thiocyanate in alcohol. Polyhedron 1997. [DOI: 10.1016/s0277-5387(97)00139-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Khan AA, Iftikhar K. Mixed-Ligand Lanthanide Complexes-VIII.aParamagnetic Shift Induced By Pr(fod)3pz and Pr(fod)3pyz in the NMR Spectrum of DI-n-Butyl Ether. ACTA ACUST UNITED AC 1995. [DOI: 10.1080/15533179508218278] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Iftikhar K. Mixed-ligand lanthanide complexes. Part VI. Electronic spectral study of some Ln(fod)3 adducts with heterocyclic amines. Inorganica Chim Acta 1987. [DOI: 10.1016/s0020-1693(00)86557-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Abstract
Holmium(III) mixed-ligand
complexes containing ligands having oxygen and nitrogen donors have been
spectrophotometrically investigated. The observed spectra in the visible region
have been analysed to calculate covalency parameters (β, b� and
δ), oscillator strengths and Judd-Ofelt parameters. The degree of
covalency in the complexes increases with increase in coordination number. The
hypersensitivity is correlated with the degree of covalency and number of
coordinated ligands. The higher values of covalency parameters, oscillator
strength and magnetic moment in the ten-coordinate HoIII is taken as
evidence of participation of f-orbitals in bonding.
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