| 1. |
- Dahl-Jensen, D., et al.
(författare)
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Eemian interglacial reconstructed from a Greenland folded ice core
- 2013
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 493:7433, s. 489-494
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Tidskriftsartikel (refereegranskat)abstract
- Efforts to extract a Greenland ice core with a complete record of the Eemian interglacial (130,000 to 115,000 years ago) have until now been unsuccessful. The response of the Greenland ice sheet to the warmer-than-present climate of the Eemian has thus remained unclear. Here we present the new North Greenland Eemian Ice Drilling ('NEEM') ice core and show only a modest ice-sheet response to the strong warming in the early Eemian. We reconstructed the Eemian record from folded ice using globally homogeneous parameters known from dated Greenland and Antarctic ice-core records. On the basis of water stable isotopes, NEEM surface temperatures after the onset of the Eemian (126,000 years ago) peaked at 8 +/- 4 degrees Celsius above the mean of the past millennium, followed by a gradual cooling that was probably driven by the decreasing summer insolation. Between 128,000 and 122,000 years ago, the thickness of the northwest Greenland ice sheet decreased by 400 +/- 250 metres, reaching surface elevations 122,000 years ago of 130 +/- 300 metres lower than the present. Extensive surface melt occurred at the NEEM site during the Eemian, a phenomenon witnessed when melt layers formed again at NEEM during the exceptional heat of July 2012. With additional warming, surface melt might become more common in the future.
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| 2. |
- Karlsson, Björn C. G., et al.
(författare)
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Structure and Dynamics of Monomer-Template Complexation: An Explanation for Molecularly Imprinted Polymer Recognition Site Heterogeneity
- 2009
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 131:37, s. 13297-13304
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Tidskriftsartikel (refereegranskat)abstract
- We here present the first simulation of a complete molecularly imprinted polymer prepolymerization system. Molecular dynamics studies were performed for a system comprising a total of 1199 discrete molecules, replicating the components and concentrations employed in the corresponding polymer synthesis. The observed interactions correlate well with results obtained from (1)H NMR spectroscopic studies. Comparison with simulations performed in the absence of cross-linking agent (ethylene dimethacrylate) demonstrated its significance in the formation of ligand recognition sites. Moreover, the influence of events such as template-template (bupivacaine) and monomer-monomer (methacrylic acid) self-association, porogen-template interactions, and template conformational variability was revealed. The template recognition capacity of the modeled polymer system was verified by synthesis of imprinted and reference polymers and subsequent radioligand binding Analysis. Collectively, through a series of statistical analyses of molecular trajectories in conjunction with spectroscopic data it was demonstrated that an ensemble of complex structures is present in the prepolymerization mixture and that this diversity is the basis for the binding site heterogeneity observed in molecularly imprinted polymers (MIPs) prepared using the noncovalent strategy.
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| 3. |
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| 4. |
- Nicholls, Ian A., et al.
(författare)
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Theoretical and Computational Strategies for Rational Molecularly Imprinted Polymer Design
- 2009
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Ingår i: Biosensors & bioelectronics. - : Elsevier BV. - 0956-5663 .- 1873-4235. ; 25:3, s. 543-552
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Tidskriftsartikel (refereegranskat)abstract
- The further evolution of molecularly imprinted polymer science and technology necessitates the development of robust predictive tools capable of handling the complexity of molecular imprinting systems. A combination of the rapid growth in computer power over the past decade and significant software developments have opened new possibilities for simulating aspects of the complex molecular imprinting process. We present here a survey of the current status of the use of in silico-based approaches to aspects of molecular imprinting. Finally, we highlight areas where ongoing and future efforts should yield information critical to our understanding of the underlying mechanisms sufficient to permit the rational design of molecularly imprinted polymers.
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| 5. |
- Golker, Kerstin, et al.
(författare)
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Hydrogen bond diversity in the pre-polymerization stage contributes to morphology and MIP-template recognition - MAA versus MMA
- 2015
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Ingår i: European Polymer Journal. - : Elsevier BV. - 0014-3057 .- 1873-1945. ; 66, s. 558-568
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Tidskriftsartikel (refereegranskat)abstract
- This report demonstrates that the diversity of hydrogen bond interactions present in molecularly imprinted polymer pre-polymerization mixtures, typically associated with binding-site heterogeneity, can also contribute to morphological characteristics that may influence polymer-template recognition. Comparisons have been made between a series of bupivacaine molecularly imprinted methacrylic acid (MAA)-ethylene glycol dimethacrylate (EGDMA) copolymers and a series of analogous methyl methacrylate (MMA)-EGDMA copolymers using comprehensive molecular dynamics studies of the respective pre-polymerization mixtures, template-polymer binding studies and detailed BET surface area and BJH porosity analyses. The role of the carboxylic acid functionality of MAA, and in particular the acidic proton, in generating morphological features conducive to analyte access (slit-like rather than ink bottle-like structures) and recognition is discussed.
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| 6. |
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| 7. |
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| 8. |
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| 9. |
- Nicholls, Ian A., et al.
(författare)
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Rational design of biomimetic molecularly imprinted materials : theoretical and computational strategies for guiding nanoscale structured polymer development
- 2011
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 400:6, s. 1771-1786
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Forskningsöversikt (refereegranskat)abstract
- In principle, molecularly imprinted polymer science and technology provides a means for ready access to nano-structured polymeric materials of predetermined selectivity. The versatility of the technique has brought it to the attention of many working with the development of nanomaterials with biological or biomimetic properties for use as therapeutics or in medical devices. Nonetheless, the further evolution of the field necessitates the development of robust predictive tools capable of handling the complexity of molecular imprinting systems. The rapid growth in computer power and software over the past decade has opened new possibilities for simulating aspects of the complex molecular imprinting process. We present here a survey of the current status of the use of in silico-based approaches to aspects of molecular imprinting. Finally, we highlight areas where ongoing and future efforts should yield information critical to our understanding of the underlying mechanisms sufficient to permit the rational design of molecularly imprinted polymers.
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| 10. |
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| 11. |
- Nicholls, Ian A., et al.
(författare)
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Theoretical and Computational Strategies for the Study of the Molecular Imprinting Process and Polymer Performance
- 2015
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Ingår i: Molecularly Imprinted Polymers In Biotechnology. - Cham, Switzerland : Springer. - 0724-6145 .- 1616-8542. - 9783319207292 - 9783319207285 ; , s. 25-50
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Bokkapitel (refereegranskat)abstract
- The development of in silico strategies for the study of the molecular imprinting process and the properties of molecularly imprinted materials has been driven by a growing awareness of the inherent complexity of these systems and even by an increased awareness of the potential of these materials for use in a range of application areas. Here we highlight the development of theoretical and computational strategies that are contributing to an improved understanding of the mechanisms underlying molecularly imprinted material synthesis and performance, and even their rational design.
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| 12. |
- Nicholls, Ian A., et al.
(författare)
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Theoretical and Computational Strategies in Molecularly Imprinted Polymer Development
- 2018
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Ingår i: Molecularly Imprinted Polymers for Analytical Chemistry Applications. - London : Royal Society of Chemistry. - 9781782626473 - 9781788010474 - 9781788014274 ; , s. 197-226
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Bokkapitel (refereegranskat)abstract
- Theoretical and computational studies of molecular imprinting have helped provide valuable insights concerning the nature of the molecular-level events underlying the recognition characteristics of molecularly imprinted materials. Here, we first present an overview of a thermodynamic treatment of factors governing the behaviour of these functional materials, and then a summary of the development and current status of the use of computational strategies for studying aspects of molecular imprinting and the resulting material properties.
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| 13. |
- Olsson, Gustaf D., et al.
(författare)
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Mechanism of Phenylalanine Anilide Molecularly Imprinted Polymer - Template Recognition: The Role of Template Dimerization
- 2010
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Konferensbidrag (refereegranskat)abstract
- It is now widely accepted that the recognition properties of a MIP are derived from molecular level events present during the prepolymerization stage.1 Studies regarding the nature and extent of template complexation during this stage should therefore yield valuable information regarding the template recognition properties of the final MIP. One method of great potential for illuminating molecular level details in this area of MIP research is molecular dynamics (MD).2 MD simulations enable studies of molecular-level events in MIP prepolymerization mixtures.Phenylalanine anilide (PA) is a molecule that has been extensively used as a template in a series of seminal molecular imprinting studies.3-5 In an effort to elucidate the origin to the imprinting effect, Sellergren, Lepistö and Mosbach proposed that selective high-affinity sites in the PA-MIP were based on functional monomer-template complexation of a 2:1 stoichiometry.3 In a follow-up study, Katz and Davis presented results that revealed further information regarding the origin of recognition in PA-MIPs.5 It was suggested that the template recognition sites were based on functional monomer-template complexes of 1:1 stoichiometry, and also that the formation of higher order template-template complexes has important effects on the final PA-MIP recognition properties. In light of this conjecture and several more recent studies highlighting the diversity of template complexation mechanisms in prepolymerization mixtures, have pointed at the complexity and diversity in the ensemble of complexes leading to the final “molecular memory”.Here we present the novel insights into the molecular basis for PA-MIP template recognition derived from a series of MD simulations of the PA-MIP prepolymerisation systems. Data support the presence of PA-PA complexes and that the most statistically prevalent stoichiometry functional monomer-PA complexes was 1:1. The role of cross-linker is also discussed. This study highlights the potential of all component MD studies for rational MIP design. (1) Alexander, C.; Andersson, H.S.; Andersson, L.I.; Ansell, R.J.; Kirsch, N.; Nicholls, I.A.; O'Mahony, J.; Whitcombe, M.J. Molecular imprinting science and technology: A survey of the literature for the years up to and including 2003. Journal of Molecular Recognition 2006, 19, 106-180.(2) Nicholls, I.A.; Andersson, H.S.; Charlton, C; Henschel, H.; Karlsson, B.C.G.; Karlsson, J.G.; O’Mahony, J.; Rosengren, A.M.; Rosengren, J.K.; Wikman, S. Theoretical and computational stratgies for rational molecularly imprinted polymer design. Biosensors and Bioelectronics 2009, 25, 543-552(3) Sellergren, B.; Lepistoe, M.; Mosbach, K.. Highly enantioselective and substrate-selective polymers obtained by molecular imprinting utilizing noncovalent interactions. NMR and chromatographic studies on the nature of recognition. Journal of American Chemical Society 1988, 110, 5853-5860(4) Sellergren, B.. Molecular imprinting by noncovalent interactions: Tailor-made chiral stationary phases of high selectivity and sample load capacity. Chirality 1989, 1, 63-68(5) Katz, A.; Davis, M.E. Investigations into the mechanism of molecular recognition with imprinted polymers. Macromolecules 1999, 32, 4113-4121
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| 14. |
- Olsson, Gustaf D., et al.
(författare)
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Mechanisms underlying molecularly imprinted polymer molecular memory and the role of crosslinker : resolving debate on the nature of template recognition in phenylalanine anilide imprinted polymers
- 2012
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Ingår i: Journal of Molecular Recognition. - : Wiley. - 0952-3499 .- 1099-1352. ; 25:2, s. 69-73
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Tidskriftsartikel (refereegranskat)abstract
- A series of molecular dynamics simulations of prepolymerization mixtures for phenylalanine anilide imprinted co-(ethylene glycol dimethacrylate-methacrylic acid) molecularly imprinted polymers have been employed to investigate the mechanistic basis for template selective recognition in these systems. This has provided new insights on the mechanisms underlying template recognition, in particular the significant role played by the crosslinking agent. Importantly, the study supports the occurrence of template self-association events that allows us to resolve debate between the two previously proposed models used to explain this system's underlying recognition mechanisms. Moreover, the complexity of the molecular level events underlying template complexation is highlighted by this study, a factor that should be considered in rational molecularly imprinted polymer design, especially with respect to recognition site heterogeneity.
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| 15. |
- Olsson, Gustaf D., et al.
(författare)
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The nature and extent of interactions in phenylalanine anilide molecularly imprinted polymer prepolymerisation mixtures: a new model for the basis for ligand-selective recognition
- 2010
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Konferensbidrag (refereegranskat)abstract
- In this work, classical molecular dynamics (MD) simulations have been used to provide unique insights on the nature and extent of intermolecular interactions present in a phenylalanine anilide (PA) molecularly imprinted polymers (MIP) prepolymerization mixture.Molecular Imprinting is a technique for producing highly selective synthetic receptors for a predetermined molecular structure, and involves the formation of cavities in a synthetic polymer matrix that are of complementary functional and structural character to a template molecule.1 It is generally accepted that the recognition properties of a MIP is a product of the interactions between monomers and template during the prepolymerization stage. Accordingly, studies of the nature and extent of the interactions present in prepolymerization mixtures, in patricular those involving template, should yield information which can be related to the observed recognition properties of the final MIP.Phenylalanine anilide MIPs have been the subject of a significant number of studies aimed at producing an understanding of the mechanisms underlying the recognition processes. Interestingly, two different models have been proposed to explain the behaviour of PA-MIPs. Studies by Sellergren et al. proposed that template selectivity, was a consequence of the presence of a functional monomer-template complexes of 2:1 stoichiometry.2 Later, however, Katz and Davis proposed an alternative model,3 where the template (PA) recognition sites in the MIP were suggested to arise from functional monomer-template complexes of 1:1 stoichiometry in combination with the presence of higher order template-template complexes.To resolve this conjecture, we performed a series of MD studies, the results of which demonstrated both the presence of PA-PA self association complexes, and that the most statistically prevalent monomer-PA complex stoichiometry was of a 1:1 nature, though differetn in character from that proposed by Katz and Davis. Moreover, the role of cross-linker in forming recognition sites was apparnet in these studies, a fact not previously considered. ReferencesAlexander C, Andersson HS, Andersson LI, Ansell RJ, Kirsh N, Nicholls IA, O’Mahony J, Whitcombe MJ. Molecular imprinting science and technology: A survey of the literature for the years up to and including 2003. Journal of Molecular Recognition 2006;19:106-180Sellergren B, Lepistö M, Mosbach K. Highly enantioselective and substrate selective polymers obtained by molecular imprinting utilizing noncovalent interactions. NMR and chromatographic studies on the nature of recognition. Journal of the American Chemical Society 1988;110:5853-5860Katz A, Davis ME. Investigations into the mechanisms of molecular recognition with imprinted polymers. Macromolecules 1999;32:4113-4121
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| 16. |
- Olsson, Gustaf D., et al.
(författare)
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The Nature and Extent of Template-Template Complexation in Phenylalanine Anilide Molecularly Imprinted Polymers
- 2010
-
Konferensbidrag (refereegranskat)abstract
- The molecular imprinting technique has received significant attention due to its utility in the production of synthetic polymeric materials with predetermined ligand recognition properties [1].It is generally accepted that the recognition properties of a molecularly imprinted polymer (MIP) is established during the prepolymerization stage. Previous investigations on the nature and extent of template prepolymerization complexation in a phenylalanine anilide (PA) MIP pointed at the complexity and diversity in the ensemble of complexes leading to the final “molecular memory”. In particular, conflicting models have been used to explain the observed molecular memory. Sellergren, Lepistö and Mosbach [2] proposed that selective, high-affinity sites in the final MIP were based on functional monomer-PA complexation of a 2:1 stoichiometry. Later, Katz and Davis [3] proposed that the template recognition sites arose due to a 1:1 functional monomer-template complex stoichiometry and that the effect of template dimerization is critical for the observed PA-MIP recognition properties.In this study, we have attempted to shed new light on this as yet unresolved conflict using a series of molecular dynamics (MD) simulations. Results demonstrated the presence of PA-PA complexes and that the most statistically prevalent stoichiometry of functional monomer-PA complexes was of 1:1.[1] Alexander C, Andersson HS, Andersson LI, Ansell R, Kirsch N, Nicholls IA et al. Molecular imprinting science and technology: a survey of the literature for the years up to and including 2003, Journal of Molecular Recognition, 19, 106-180 (2006).[2] Sellergren B, Lepistö M, Mosbach K. Highly enantioselective and substrate selective polymers obtained by molecular imprinting utilizing noncovalent interactions. NMR and chromatographic studies on the nature of recognition, Journal of the American Chemical Society, 110, 5853-5860 (1988).[3] Katz A, Davis ME. Investigations into the mechanisms of molecular recognition with imprinted polymers, Macromolecules, 32, 4113-4121 (1999).
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| 17. |
- Shoravi, Siamak, et al.
(författare)
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In silico screening of molecular imprinting prepolymerization systems : oseltamivir selective polymers through full-system molecular dynamics-based studies
- 2016
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Ingår i: Organic and biomolecular chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 14:18, s. 4210-4219
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Tidskriftsartikel (refereegranskat)abstract
- All-component molecular dynamics studies were used to probe a library of oseltamivir molecularly imprinted polymer prepolymerization mixtures. Polymers included one of five functional monomers (acrylamide, hydroxyethylmethacrylate, methacrylic acid, 2-(triflouromethyl)acrylic acid, 4-vinylpyridine) and one of three porogens (acetonitrile, chloroform, methanol) combined with the crosslinking agent ethylene glycol dimethacrylate and initiator 2,2'-azobis(2-methylpropionitrile). Polymers were characterized by nitrogen gas sorption measurements and SEM, and affinity studies performed using radioligand binding in various media. In agreement with the predictions made from the simulations, polymers prepared in acetonitrile using either methacrylic or trifluoromethacrylic acid demonstrated the highest affinities for oseltamivir. Further, the ensemble of interactions observed in the methanol system provided an explanation for the morphology of polymers prepared in this solvent. The materials developed here offer potential for use in solid-phase extraction or for catalysis. The results illustrate the strength of this in silico strategy as a potential prognostic tool in molecularly imprinted polymer design.
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| 18. |
- Shoravi, Siamak, et al.
(författare)
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Towards Synthetic Neuraminidases
- 2010
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Konferensbidrag (refereegranskat)abstract
- Influenza endemics and pandemics have been a menace to humanity through the ages and pose ominous threats and with dire consequences for humanity [1]. A better understanding of the virus, the epidemiology of the disease, and its structure and function is essential for creating new therapies and even for better understanding resistance to existing treatments. At the molecular level the two capside proteins Neuraminidase and Hemagglutinin are engaged in interactions with host cell surface sialic acid residues, and are critical for contagion and budding off of the virus into and from the cell, and have been the targets for drug development strategies [2]. The rise of strains of the virus resistant to drugs targeting Neuraminidase make it crucial to develop techniques for better understanding of the virus and hence design of better antiviral agents [3].In this study a combination of molecular dynamics (MD) and NMR spectroscopy [4-7] is been utilised in order to screen some 60 polymers for candidate systems [8] for use in the preparation of synthetic polymer neauraminidase mimics. Progress in the design, synthesis and evaluation of these materials shall be presented.References1. Webster et al., Microbiol. Rev., 56, 152-175 (1992).2. von Itzstein et al., Nature, 263, 418-423 (1993).3. Lindberg et al., Chemosphere, 57, 1479-1488. (2004).4. Svensson et al., J. Chromatogr. A, 1024, 39-44 (2004).5. O’Mahony et al., Analyst, 23, 1147-1115 (2007).6. Karlsson et al., J. Am. Chem. Soc., 131, 13297-13304 (2009).7. Nicholls et al., Biosens. Bioelectron., 25, 553-557 (2009).8. Shoravi et al., unpublished results (2010).
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| 19. |
- Wiklander, Jesper G., et al.
(författare)
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A synthetic polymer with avidin-like binding properties
- 2010
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Konferensbidrag (refereegranskat)abstract
- A series of streptavidin mimicking molecularly imprinted polymers has been developed and evaluated for their biotin binding characteristics. A combination of molecular dynamics and NMR spectroscopy was used to examine potential polymer systems, in particular with the functional monomers methacrylic acid and 2-acrylamidopyridine. Synthesis of co-polymers of ethylene dimethacrylate and one or both of these functional monomers was performed. A combination of radioligand binding studies and surface area analyses (BET, SEM) demonstrated the presence of selectivity in polymers prepared using methacrylic acid as functional monomer. This correlated well with the molecular dynamics studies, showing the power of this methodology as a prognostic tool for predicting the behaviour of molecularly imprinted polymers.
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| 20. |
- Wiklander, Jesper G., 1974-, et al.
(författare)
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Towards a synthetic avidin mimic
- 2011
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 400:5, s. 1397-1404
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Tidskriftsartikel (refereegranskat)abstract
- A series of streptavidin-mimicking molecularly imprinted polymers has been developed and evaluated for their biotin binding characteristics. A combination of molecular dynamics and NMR spectroscopy was used to examine potential polymer systems, in particular with the functional monomers methacrylic acid and 2-acrylamidopyridine. The synthesis of copolymers of ethylene dimethacrylate and one or both of these functional monomers was performed. A combination of radioligand binding studies and surface area analyses demonstrated the presence of selectivity in polymers prepared using methacrylic acid as the functional monomer. This was predicted by the molecular dynamics studies showing the power of this methodology as a prognostic tool for predicting the behavior of molecularly imprinted polymers.
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| 21. |
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| 22. |
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| 23. |
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| 24. |
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| 25. |
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| 26. |
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| 27. |
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| 28. |
- Nicholls, Ian A., et al.
(författare)
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Can we rationally design molecularly imprinted polymers?
- 2001
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Ingår i: Analytica Chimica Acta. ; 435:1, s. 9-18
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Tidskriftsartikel (refereegranskat)abstract
- The nearly exponential growth in the molecular imprinting literature has to a large extent been fuelled by an increasing awareness of the potential of molecular imprinting based technologies. Despite the acceptance of the technique by cognate disciplines and the demonstration of its usefulness in a number of enabling technologies, relatively little is known about the molecular level events underlying the imprinting process and subsequent recognition events. What rules govern imprint formation? Can we use such rules to rationally design molecularly imprinted polymers?
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| 29. |
- Nicholls, Ian A., et al.
(författare)
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Molecularly imprinted polymers: unique possibilities for environmental monitoring
- 2002
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Ingår i: Proceedings of Kalmar Eco-Tech'01 : conference on leachate and waste water treatment with high-tech and natural systems : the 3rd International Conference on the Establishment of Cooperation Between Companies/Institutions in the Nordic Countries and the Countries in the Baltic Sea Region : November 26 to 28, 2001 Kalmar, Sweden. - : Högskolan i Kalmar. ; , s. 285-288, s. 285-288
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 30. |
- Petcu, Mira, et al.
(författare)
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Probing the limits of molecular imprinting: strategies with a template of limited size and functionality
- 2009
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Ingår i: Journal of Molecular Recognition. - : Wiley. - 0952-3499 .- 1099-1352. ; 22:1, s. 18-25
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Tidskriftsartikel (refereegranskat)abstract
- A series of polymers molecularly imprinted with the general anaesthetic propofol were synthesized using both semi- and non-covalent approaches. The polymers were evaluated with respect to template rebinding in both aqueous and organic media. In aqueous media, the observed propofol binding in these polymer systems was largely hydrophobic and non-specific in nature. In non-polar solvents such as hexane, electrostatic (hydrogen bonding) interactions dominate resulting in some selectivity. The implication of these results, in conjunction with those obtained using structures of similar size in other studies, is that propofol, a template possessing limited functionality and size, appears to define the lower limit for template size and degree of functionalization that can be used for the creation of ligand-selective recognition sites in molecularly imprinted polymers. Furthermore, studies with alternative ligands indicate that the steric crowding of a ligand's functionality to the polymer contributes to the extent of polymer-ligand recognition.
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| 31. |
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| 32. |
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| 33. |
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| 34. |
- Rosengren, Annika M., et al.
(författare)
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Dielectric constants are not enough: Principal component analysis of the influence of solvent properties on molecularly imprinted polymer–ligand rebinding
- 2009
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Ingår i: Biosensors & bioelectronics. - : Elsevier BV. - 0956-5663 .- 1873-4235. ; 25:3, s. 553-557
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Tidskriftsartikel (refereegranskat)abstract
- The influence of the physical properties of incubation medium on the rebinding of template to bupivacaine molecularly imprinted and non-imprinted methacrylic acid–ethylene dimethacrylate co-polymers has been studied. Principal component analysis (PCA) was employed to identify the factors with the greatest influence on binding. While the dielectric constant (D) made a significant contribution to describing the observed binding, the influence of polarity as reflected in the Snyder polarity index (SPI) was also demonstrated to make a significant contribution. The use of solvents containing hydroxyl functionality in particular was observed to exert unique effects on recognition. The variation in solvent influence on binding at constant D motivates more complex analyses when studying MIP–ligand recognition.
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| 35. |
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| 36. |
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| 37. |
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| 38. |
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| 39. |
- Rosengren-Holmberg, Jenny P., et al.
(författare)
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Synthesis and ligand recognition of paracetamol selective polymers: semi-covalent versus non-covalent molecular imprinting.
- 2009
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Ingår i: Organic and biomolecular chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 7, s. 3148-3155
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Tidskriftsartikel (refereegranskat)abstract
- Three molecular imprinting strategies, each based upon a series of ethylene glycol dimethacrylate (EGDMA) cross-linked co-polymers, have been used to produce materials selective for the commonly used analgesic and antipyretic agent paracetamol (p-acetaminophen or 4-acetamidophenol) (1). The polymers were synthesised using either a semi-covalent imprinting strategy based upon 4-acetamidophenyl-(4-vinylphenyl) carbonate (4) or a non-covalent strategy based on methacrylic acid (MAA) as the functional monomer, or by employing a combination of these strategies. Radioligand binding studies demonstrated low template affinity in polymers offering only a single electrostatic interaction point for recognition via the phenolic residue in the template, whereas binding was substantially increased upon the introduction of a second binding mode, namely interaction at the acetamide moiety. HPLC analyses revealed no imprinting effect in the purely semi-covalent system, and only a minor effect in the purely non-covalent systems. However, a pronounced imprinting effect was demonstrated for polymers prepared by a combination of semi-covalent and non-covalent imprinting. This study illustrates a limitation of both the non-covalent and the semi-covalent strategies when it comes to achieving imprinted selectivity for small and poorly functionalised templates such as paracetamol. Parallels with conclusions from studies with antibodies are discussed.
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| 40. |
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| 41. |
- Svenson, Johan, et al.
(författare)
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1H-nuclear magnetic resonance study of the molecular imprinting of (-)-nicotine : template self-association, a molecular basis for cooperative ligand binding
- 2004
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Ingår i: Journal of Chromatography A. - : Elsevier. - 0021-9673 .- 1873-3778. ; 1024:1-2, s. 39-44
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, the interactions of components in a (−)-nicotine molecular imprinting polymerization mixture have been studied by NMR spectroscopy. The dissociation constants for complexation of template by a functional monomer analogue, acetic acid, have been determined. Nicotine was shown to self-associate at concentrations comparable to those used in previous molecular imprinting studies (app Kdiss=0.082 M in CDCl3 at 298 K). The extent of self-association was enhanced by the presence of acetic acid. Previous studies on (−)-nicotine–imprinted methacrylic acid–ethylene dimethacrylate co-polymers suggested the involvement of recognition sites for template–template complexes. Collectively these results provide the first direct evidence for the presence of template–template complexes, and support the previously hypothesized basis for cooperative ligand recognition events in this polymer system.
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| 42. |
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| 43. |
- Svensson, Anneli, 1972-, et al.
(författare)
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Genetic Variant Score and Arrhythmogenic Right Ventricular Cardiomyopathy Phenotype in Plakophilin-2 Mutation Carriers
- 2021
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Ingår i: Cardiology. - : S. Karger. - 0008-6312 .- 1421-9751. ; 146:6, s. 763-771
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Whether detailed genetic information contributes to risk stratification of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) remains uncertain. Pathogenic genetic variants in some genes seem to carry a higher risk for arrhythmia and earlier disease onset than others, but comparisons between variants in the same gene have not been done. Combined Annotation Dependent Depletion (CADD) score is a bioinformatics tool that measures the pathogenicity of each genetic variant. We hypothesized that a higher CADD score is associated with arrhythmic events and earlier age at ARVC manifestations in individuals carrying pathogenic or likely pathogenic genetic variants in plakophilin-2 (PKP2).METHODS: CADD scores were calculated using the data from pooled Scandinavian and North American ARVC cohorts, and their association with cardiac events defined as ventricular tachycardia/ventricular fibrillation (VT/VF) or syncope and age at definite ARVC diagnosis were assessed.RESULTS: In total, 33 unique genetic variants were reported in 179 patients (90 males, 71 probands, 96 with definite ARVC diagnosis at a median age of 35 years). Cardiac events were reported in 76 individuals (43%), of whom 53 had sustained VT/VF (35%). The CADD score was neither associated with age at cardiac events (HR 1.002, 95% CI: 0.953-1.054, p = 0.933) nor with age at definite ARVC diagnosis (HR 0.992, 95% CI: 0.947-1.039, p = 0.731).CONCLUSION: No correlation was found between CADD scores and clinical manifestations of ARVC, indicating that the score has no additional risk stratification value among carriers of pathogenic or likely pathogenic PKP2 genetic variants.
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