1
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Schuhmann F, Ramsay JL, Kattnig DR, Solov’yov IA. Structural Rearrangements of Pigeon Cryptochrome 4 Undergoing a Complete Redox Cycle. J Phys Chem B 2024; 128:3844-3855. [PMID: 38568745 PMCID: PMC11056986 DOI: 10.1021/acs.jpcb.4c00424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 03/04/2024] [Accepted: 03/11/2024] [Indexed: 04/26/2024]
Abstract
Cryptochrome is currently the major contender of a protein to underpin magnetoreception, the ability to sense the Earth's magnetic field. Among various types of cryptochromes, cryptochrome 4 has been identified as the likely magnetoreceptor in migratory birds. All-atom molecular dynamics (MD) studies have offered first insights into the structural dynamics of cryptochrome but are limited to a short time scale due to large computational demands. Here, we employ coarse-grained MD simulations to investigate the emergence of long-lived states and conformational changes in pigeon cryptochrome 4. Our coarse-grained simulations complete the picture by permitting observation on a significantly longer time scale. We observe conformational transitions in the phosphate-binding loop of pigeon cryptochrome 4 upon activation and identify prominent motions in residues 440-460, suggesting a possible role as a signaling state of the protein or as a gated interaction site for forming protein complexes that might facilitate downstream processes. The findings highlight the importance of considering longer time scales in studying cryptochrome dynamics and magnetoreception. Coarse-grained MD simulations offer a valuable tool to unravel the complex behavior of cryptochrome proteins and shed new light on the mechanisms underlying their role in magnetoreception. Further exploration of these conformational changes and their functional implications may contribute to a deeper understanding of the molecular mechanisms of magnetoreception in birds.
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Affiliation(s)
- Fabian Schuhmann
- Institute
of Physics, Carl von Ossietzky Universität
Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26129, Germany
- Niels
Bohr International Academy, Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, Copenhagen 2100, Denmark
| | - Jessica L. Ramsay
- Living
Systems Institute and Department of Physics, University of Exeter, Stocker Rd., Exeter EX4
4QD, U.K.
| | - Daniel R. Kattnig
- Living
Systems Institute and Department of Physics, University of Exeter, Stocker Rd., Exeter EX4
4QD, U.K.
| | - Ilia A. Solov’yov
- Institute
of Physics, Carl von Ossietzky Universität
Oldenburg, Carl-von-Ossietzky Str. 9-11, Oldenburg 26129, Germany
- Research
Centre for Neurosensory Science, Carl von
Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Str. 9-11, Oldenburg 26129, Germany
- Center
for Nanoscale Dynamics (CENAD), Carl von
Ossietzky Universität Oldenburg, Ammerländer Heerstr. 114-118, Oldenburg 26129, Germany
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2
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Reddygunta KKR, Callander A, Šiller L, Faulds K, Berlouis L, Ivaturi A. Scalable slot-die coated flexible supercapacitors from upcycled PET face shields. RSC Adv 2024; 14:12781-12795. [PMID: 38645514 PMCID: PMC11027888 DOI: 10.1039/d2ra06809e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 12/27/2022] [Indexed: 04/23/2024] Open
Abstract
Upcycling Covid19 plastic waste into valuable carbonaceous materials for energy storage applications is a sustainable and green approach to minimize the burden of waste plastic on the environment. Herein, we developed a facile single step activation technique for producing activated carbon consisting of spherical flower like carbon nanosheets and amorphous porous flakes from used PET [poly(ethylene terephthalate)] face shields for supercapacitor applications. The as-obtained activated carbon exhibited a high specific surface area of 1571 m2 g-1 and pore volume of 1.64 cm3 g-1. The specific capacitance of these carbon nanostructure-coated stainless steel electrodes reached 228.2 F g-1 at 1 A g-1 current density with excellent charge transport features and good rate capability in 1 M Na2SO4 aqueous electrolyte. We explored the slot-die coating technique for large-area coatings of flexible high-performance activated carbon electrodes with special emphasis on optimizing binder concentration. Significant improvement in electrochemical performance was achieved for the electrodes with 15 wt% Nafion concentration. The flexible supercapacitors fabricated using these electrodes showed high energy and power density of 21.8 W h kg-1 and 20 600 W kg-1 respectively, and retained 96.2% of the initial capacitance after 10 000 cycles at 2 A g-1 current density. The present study provides a promising sustainable approach for upcycling PET plastic waste for large area printable supercapacitors.
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Affiliation(s)
- Kiran Kumar Reddy Reddygunta
- Smart Materials Research and Device Technology (SMaRDT) Group, Department of Pure and Applied Chemistry, University of Strathclyde Thomas Graham Building Glasgow G1 1XL UK
| | - Andrew Callander
- Centre for Molecular Nanometrology, Department of Pure and Applied Chemistry, University of Strathclyde, Technology Innovation Centre 99 George Street Glasgow G1 1RD UK
| | - Lidija Šiller
- Newcastle University, School of Engineering Newcastle upon Tyne NE1 7RU UK
| | - Karen Faulds
- Centre for Molecular Nanometrology, Department of Pure and Applied Chemistry, University of Strathclyde, Technology Innovation Centre 99 George Street Glasgow G1 1RD UK
| | - Leonard Berlouis
- Smart Materials Research and Device Technology (SMaRDT) Group, Department of Pure and Applied Chemistry, University of Strathclyde Thomas Graham Building Glasgow G1 1XL UK
| | - Aruna Ivaturi
- Smart Materials Research and Device Technology (SMaRDT) Group, Department of Pure and Applied Chemistry, University of Strathclyde Thomas Graham Building Glasgow G1 1XL UK
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3
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Shiffa M, Dewes BT, Bradford J, Cottam ND, Cheng TS, Mellor CJ, Makarovskiy O, Rahman K, O'Shea JN, Beton PH, Novikov SV, Ben T, Gonzalez D, Xie J, Zhang L, Patanè A. Wafer-Scale Two-Dimensional Semiconductors for Deep UV Sensing. Small 2024; 20:e2305865. [PMID: 37798672 DOI: 10.1002/smll.202305865] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 08/29/2023] [Indexed: 10/07/2023]
Abstract
2D semiconductors (2SEM) can transform many sectors, from information and communication technology to healthcare. To date, top-down approaches to their fabrication, such as exfoliation of bulk crystals by "scotch-tape," are widely used, but have limited prospects for precise engineering of functionalities and scalability. Here, a bottom-up technique based on epitaxy is used to demonstrate high-quality, wafer-scale 2SEM based on the wide band gap gallium selenide (GaSe) compound. GaSe layers of well-defined thickness are developed using a bespoke facility for the epitaxial growth and in situ studies of 2SEM. The dominant centrosymmetry and stacking of the individual van der Waals layers are verified by theory and experiment; their optical anisotropy and resonant absorption in the UV spectrum are exploited for photon sensing in the technological UV-C spectral range, offering a scalable route to deep-UV optoelectronics.
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Affiliation(s)
- Mustaqeem Shiffa
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Benjamin T Dewes
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Jonathan Bradford
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Nathan D Cottam
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Tin S Cheng
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Christopher J Mellor
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Oleg Makarovskiy
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Kazi Rahman
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - James N O'Shea
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Peter H Beton
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Sergei V Novikov
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Teresa Ben
- University Research Institute on Electron Microscopy and Materials, IMEYMAT, Universidad de Cádiz, Cádiz, 11510, Spain
| | - David Gonzalez
- University Research Institute on Electron Microscopy and Materials, IMEYMAT, Universidad de Cádiz, Cádiz, 11510, Spain
| | - Jiahao Xie
- College of Materials Science and Engineering, Jilin University, Changchun, 130012, China
| | - Lijun Zhang
- College of Materials Science and Engineering, Jilin University, Changchun, 130012, China
| | - Amalia Patanè
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
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4
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Campbell E, Adamson H, Luxton T, Tiede C, Wälti C, Tomlinson DC, Jeuken LJC. Therapeutic drug monitoring of immunotherapies with novel Affimer-NanoBiT sensor construct. Sens Diagn 2024; 3:104-111. [PMID: 38249540 PMCID: PMC10795742 DOI: 10.1039/d3sd00126a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 10/23/2023] [Indexed: 01/23/2024]
Abstract
Concentration-therapeutic efficacy relationships have been observed for several therapeutic monoclonal antibodies (TmAb), where low circulating levels can result in ineffective treatment and high concentrations can cause adverse reactions. Rapid therapeutic drug monitoring (TDM) of TmAb drugs would provide the opportunity to adjust an individual patient's dosing regimen to improve treatment results. However, TDM for immunotherapies is currently limited to centralised testing methods with long sample-collection to result timeframes. Here, we show four point-of-care (PoC) TmAb biosensors by combining anti-idiotypic Affimer proteins and NanoBiT split luciferase technology at a molecular level to provide a platform for rapid quantification (<10 minutes) for four clinically relevant TmAb (rituximab, adalimumab, ipilimumab and trastuzumab). The rituximab sensor performed best with 4 pM limit of detection (LoD) and a quantifiable range between 8 pM-2 nM with neglectable matrix effects in serum up to 1%. After dilution of serum samples, the resulting quantifiable range for all four sensors falls within the clinically relevant range and compares favourably with the sensitivity and/or time-to-result of current ELISA standards. Further development of these sensors into a PoC test may improve treatment outcome and quality of life for patients receiving immunotherapy.
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Affiliation(s)
- Emma Campbell
- School of Biomedical Science, University of Leeds Leeds LS2 9JT UK
- Astbury Centre for Structural Molecular Biology, University of Leeds LS2 9JT UK
| | - Hope Adamson
- School of Biomedical Science, University of Leeds Leeds LS2 9JT UK
- Astbury Centre for Structural Molecular Biology, University of Leeds LS2 9JT UK
| | - Timothy Luxton
- School of Biomedical Science, University of Leeds Leeds LS2 9JT UK
- Astbury Centre for Structural Molecular Biology, University of Leeds LS2 9JT UK
| | - Christian Tiede
- Astbury Centre for Structural Molecular Biology, University of Leeds LS2 9JT UK
- School of Molecular and Cellular Biology, University of Leeds Leeds LS2 9JT UK
| | - Christoph Wälti
- School of Electronic and Electrical Engineering, University of Leeds LS2 9JT UK
| | - Darren C Tomlinson
- Astbury Centre for Structural Molecular Biology, University of Leeds LS2 9JT UK
- School of Molecular and Cellular Biology, University of Leeds Leeds LS2 9JT UK
| | - Lars J C Jeuken
- School of Biomedical Science, University of Leeds Leeds LS2 9JT UK
- Astbury Centre for Structural Molecular Biology, University of Leeds LS2 9JT UK
- Leiden Institute of Chemistry, Leiden University PO Box 9502 2300 RA Leiden The Netherlands
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5
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Bagha H, Hein R, Lim JYC, Durr CB, Sambrook MR, Beer PD. Halogen Bonding Tripodal Metallo-Receptors for Phosphate Recognition and Sensing in Aqueous-Containing Organic Media. Chemistry 2024; 30:e202302775. [PMID: 37792284 DOI: 10.1002/chem.202302775] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 10/02/2023] [Accepted: 10/03/2023] [Indexed: 10/05/2023]
Abstract
The anion recognition and electrochemical anion-sensing properties of halogen-bonding (XB) tripodal zinc(II) receptors strategically designed and constructed for tetrahedral anion guest binding are described. The XB tris(iodotriazole)-containing hosts exhibit high affinities and selectivities for inorganic phosphate over other more basic, mono-charged oxoanions such as acetate and the halides in a competitive CD3 CN/D2 O (9 : 1 v/v) aqueous solvent mixture. 1 H NMR anion binding and electrochemical voltammetric anion sensing studies with redox-active ferrocene functionalised metallo-tripodal receptor analogues, reveal each of the XB tripods as superior anion complexants when compared to their tris(prototriazole)-containing, hydrogen bonding (HB) counterparts, not only exemplifying the halogen bond as a strong alternative interaction to the traditional hydrogen bond for molecular recognition but also providing rare evidence of the ability of XB receptors to preferentially bind the "harder" phosphate oxoanion over the "softer" and less hydrated halides in aqueous containing media.
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Affiliation(s)
- Hena Bagha
- Department of Chemistry, University of Oxford Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK
| | - Robert Hein
- Department of Chemistry, University of Oxford Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK
| | - Jason Y C Lim
- Department of Chemistry, University of Oxford Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK
| | - Christopher B Durr
- Department of Chemistry, University of Oxford Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK
| | | | - Paul D Beer
- Department of Chemistry, University of Oxford Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK
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6
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Fergusson J, Wallace GQ, Sloan-Dennison S, Carland R, Shand NC, Graham D, Faulds K. Plasmonic and Photothermal Properties of Silica-Capped Gold Nanoparticle Aggregates. J Phys Chem C Nanomater Interfaces 2023; 127:24475-24486. [PMID: 38148849 PMCID: PMC10749475 DOI: 10.1021/acs.jpcc.3c07536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 11/22/2023] [Accepted: 11/27/2023] [Indexed: 12/28/2023]
Abstract
Owing to their biocompatibility, gold nanoparticles have many applications in healthcare, notably for targeted drug delivery and the photothermal therapy of tumors. The addition of a silica shell to the nanoparticles can help to minimize the aggregation of the nanoparticles upon exposure to harsh environments and protect any Raman reporters adsorbed onto the metal surface. Here, we report the effects of the addition of a silica shell on the photothermal properties of a series of gold nanostructures, including gold nanoparticle aggregates. The presence of a Raman reporter at the surface of the gold nanoparticles also allows the structures to be evaluated by surface-enhanced Raman scattering (SERS). In this work, we explore the relationship between the degree of aggregation and the position and the extinction of the near-infrared plasmon on the observed SERS intensity and in the increase in bulk temperature upon near-infrared excitation. By tailoring the concentration of the silane and the thickness of the silica shell, it is possible to improve the photothermal heating capabilities of the structures without sacrificing the SERS intensity or changing the optical properties of the gold nanoparticle aggregates.
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Affiliation(s)
- Jodie Fergusson
- Centre
for Nanometrology, Department of Pure and Applied Chemistry, Technology and Innovation Centre, 99 George Street, Glasgow G1 1RD, U.K.
| | - Gregory Q. Wallace
- Centre
for Nanometrology, Department of Pure and Applied Chemistry, Technology and Innovation Centre, 99 George Street, Glasgow G1 1RD, U.K.
| | - Sian Sloan-Dennison
- Centre
for Nanometrology, Department of Pure and Applied Chemistry, Technology and Innovation Centre, 99 George Street, Glasgow G1 1RD, U.K.
| | - Ruairí Carland
- Centre
for Nanometrology, Department of Pure and Applied Chemistry, Technology and Innovation Centre, 99 George Street, Glasgow G1 1RD, U.K.
| | - Neil C. Shand
- Defence
Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ, U.K.
| | - Duncan Graham
- Centre
for Nanometrology, Department of Pure and Applied Chemistry, Technology and Innovation Centre, 99 George Street, Glasgow G1 1RD, U.K.
| | - Karen Faulds
- Centre
for Nanometrology, Department of Pure and Applied Chemistry, Technology and Innovation Centre, 99 George Street, Glasgow G1 1RD, U.K.
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7
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Harwood LA, Xiong Z, Christensen KE, Wang R, Wong LL, Robertson J. Selective P450 BM3 Hydroxylation of Cyclobutylamine and Bicyclo[1.1.1]pentylamine Derivatives: Underpinning Synthetic Chemistry for Drug Discovery. J Am Chem Soc 2023; 145:27767-27773. [PMID: 38051939 PMCID: PMC10740007 DOI: 10.1021/jacs.3c10542] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 11/13/2023] [Accepted: 11/15/2023] [Indexed: 12/07/2023]
Abstract
Achieving single-step syntheses of a set of related compounds divergently and selectively from a common starting material affords substantial efficiency gains when compared with preparing those same compounds by multiple individual syntheses. In order for this approach to be realized, complementary reagent systems must be available; here, a panel of engineered P450BM3 enzymes is shown to fulfill this remit in the selective C-H hydroxylation of cyclobutylamine derivatives at chemically unactivated sites. The oxidations can proceed with high regioselectivity and stereoselectivity, producing valuable bifunctional intermediates for synthesis and applications in fragment-based drug discovery. The process also applies to bicyclo[1.1.1]pentyl (BCP) amine derivatives to achieve the first direct enantioselective functionalization of the bridging methylenes and open a short and efficient route to chiral BCP bioisosteres for medicinal chemistry. The combination of substrate, enzyme, and reaction engineering provides a powerful general platform for small-molecule elaboration and diversification.
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Affiliation(s)
- Lucy A. Harwood
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K.
| | - Ziyue Xiong
- Oxford
Suzhou Centre for Advanced Research, Ruo Shui Road, Suzhou Industrial Park, Suzhou, Jiangsu 215123, P. R. China
| | - Kirsten E. Christensen
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K.
| | - Ruiyao Wang
- Wisdom
Lake Academy of Pharmacy, Xi’an Jiaotong-Liverpool
University, Suzhou Industrial
Park, Suzhou, Jiangsu, 215123, P. R. China
| | - Luet L. Wong
- Oxford
Suzhou Centre for Advanced Research, Ruo Shui Road, Suzhou Industrial Park, Suzhou, Jiangsu 215123, P. R. China
- Inorganic
Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K.
| | - Jeremy Robertson
- Chemistry
Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K.
- Oxford
Suzhou Centre for Advanced Research, Ruo Shui Road, Suzhou Industrial Park, Suzhou, Jiangsu 215123, P. R. China
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8
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Troth TD, McInnes RS, Dunn SJ, Mirza J, Whittaker AH, Goodchild SA, Loman NJ, Harding SV, van Schaik W. Differences in the gut microbiota between Gurkhas and soldiers of British origin. PLoS One 2023; 18:e0292645. [PMID: 38113233 PMCID: PMC10729956 DOI: 10.1371/journal.pone.0292645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 09/26/2023] [Indexed: 12/21/2023] Open
Abstract
Previous work indicated that the incidence of travellers' diarrhoea (TD) is higher in soldiers of British origin, when compared to soldiers of Nepalese descent (Gurkhas). We hypothesise that the composition of the gut microbiota may be a contributing factor in the risk of developing TD in soldiers of British origin. This study aimed to characterise the gut microbial composition of Gurkha and non-Gurkha soldiers of the British Army. Recruitment of 38 soldiers (n = 22 Gurkhas, n = 16 non-Gurkhas) and subsequent stool collection, enabled shotgun metagenomic sequencing-based analysis of the gut microbiota. The microbiota of Gurkhas had significantly (P < 0.05) lower diversity, for both Shannon and Simpson diversity indices, using species level markers than the gut microbiota of non-Gurkha soldiers. Non-metric Multidimensional Scaling (NMDS) of the Bray-Curtis distance matrix revealed a significant difference in the composition of the gut microbiota between Gurkhas and non-Gurkha soldiers, at both the species level (P = 0.0178) and the genus level (P = 0.0483). We found three genera and eight species that were significantly enriched in the non-Gurkha group and one genus (Haemophilus) and one species (Haemophilus parainfluenzae) which were enriched in the Gurkha group. The difference in the microbiota composition between Gurkha soldiers and soldiers of British origin may contribute to higher colonization resistance against diarrhoeal pathogens in the former group. Our findings may enable further studies into interventions that modulate the gut microbiota of soldiers to prevent TD during deployment.
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Affiliation(s)
- Thomas D. Troth
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Ross S. McInnes
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Steven J. Dunn
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Jeremy Mirza
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Annalise H. Whittaker
- CBR Division, Defence and Science Technology Laboratory, Salisbury, Wiltshire, United Kingdom
| | - Sarah A. Goodchild
- CBR Division, Defence and Science Technology Laboratory, Salisbury, Wiltshire, United Kingdom
| | - Nicholas J. Loman
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Sarah V. Harding
- CBR Division, Defence and Science Technology Laboratory, Salisbury, Wiltshire, United Kingdom
- School of Respiratory Sciences, University of Leicester, Leicester, United Kingdom
| | - Willem van Schaik
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
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9
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Selbmann A, Miller PJO, Wensveen PJ, Svavarsson J, Samarra FIP. Call combination patterns in Icelandic killer whales (Orcinus orca). Sci Rep 2023; 13:21771. [PMID: 38065973 PMCID: PMC10709340 DOI: 10.1038/s41598-023-48349-1] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 11/25/2023] [Indexed: 12/18/2023] Open
Abstract
Acoustic sequences have been described in a range of species and in varying complexity. Cetaceans are known to produce complex song displays but these are generally limited to mysticetes; little is known about call combinations in odontocetes. Here we investigate call combinations produced by killer whales (Orcinus orca), a highly social and vocal species. Using acoustic recordings from 22 multisensor tags, we use a first order Markov model to show that transitions between call types or subtypes were significantly different from random, with repetitions and specific call combinations occurring more often than expected by chance. The mixed call combinations were composed of two or three calls and were part of three call combination clusters. Call combinations were recorded over several years, from different individuals, and several social clusters. The most common call combination cluster consisted of six call (sub-)types. Although different combinations were generated, there were clear rules regarding which were the first and last call types produced, and combinations were highly stereotyped. Two of the three call combination clusters were produced outside of feeding contexts, but their function remains unclear and further research is required to determine possible functions and whether these combinations could be behaviour- or group-specific.
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Affiliation(s)
- Anna Selbmann
- Faculty of Life and Environmental Sciences, University of Iceland, Reykjavík, Iceland.
| | - Patrick J O Miller
- Sea Mammal Research Unit, School of Biology, University of St Andrews, St Andrews, UK
| | - Paul J Wensveen
- Faculty of Life and Environmental Sciences, University of Iceland, Reykjavík, Iceland
| | - Jörundur Svavarsson
- Faculty of Life and Environmental Sciences, University of Iceland, Reykjavík, Iceland
| | - Filipa I P Samarra
- Institute of Research Centres, University of Iceland, Vestmannaeyjar, Iceland
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10
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Wilson A, Wilkes S, Teramoto Y, Hale S. Multimodal analysis of disinformation and misinformation. R Soc Open Sci 2023; 10:230964. [PMID: 38126058 PMCID: PMC10731323 DOI: 10.1098/rsos.230964] [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] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 11/22/2023] [Indexed: 12/23/2023]
Abstract
The use of disinformation and misinformation campaigns in the media has attracted much attention from academics and policy-makers. Multimodal analysis or the analysis of two or more semiotic systems-language, gestures, images, sounds, among others-in their interrelation and interaction is essential to understanding dis-/misinformation efforts because most human communication goes beyond just words. There is a confluence of many disciplines (e.g. computer science, linguistics, political science, communication studies) that are developing methods and analytical models of multimodal communication. This literature review brings research strands from these disciplines together, providing a map of the multi- and interdisciplinary landscape for multimodal analysis of dis-/misinformation. It records the substantial growth starting from the second quarter of 2020-the start of the COVID-19 epidemic in Western Europe-in the number of studies on multimodal dis-/misinformation coming from the field of computer science. The review examines that category of studies in more detail. Finally, the review identifies gaps in multimodal research on dis-/misinformation and suggests ways to bridge these gaps including future cross-disciplinary research directions. Our review provides scholars from different disciplines working on dis-/misinformation with a much needed bird's-eye view of the rapidly emerging research of multimodal dis-/misinformation.
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Affiliation(s)
- Anna Wilson
- Oxford School of Global and Area Studies, University of Oxford, Oxford OX1 2JD, UK
| | - Seb Wilkes
- Department of Physics, University of Oxford, Oxford, UK
| | | | - Scott Hale
- Oxford Internet Institute, University of Oxford, Oxford, UK
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11
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Harris DJ, Wilson MR, Chillingsworth K, Mitchell G, Smith S, Arthur T, Brock K, Vine SJ. Can cognitive training capitalise on near transfer effects? Limited evidence of transfer following online inhibition training in a randomised-controlled trial. PLoS One 2023; 18:e0293657. [PMID: 37948381 PMCID: PMC10637678 DOI: 10.1371/journal.pone.0293657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 10/17/2023] [Indexed: 11/12/2023] Open
Abstract
Despite early promise, cognitive training research has failed to deliver consistent real-world benefits and questions have been raised about the experimental rigour of many studies. Several meta-analyses have suggested that there is little to no evidence for transfer of training from computerised tasks to real-world skills. More targeted training approaches that aim to optimise performance on specific tasks have, however, shown more promising effects. In particular, the use of inhibition training for improving shoot/don't-shoot decision-making has returned positive far transfer effects. In the present work, we tested whether an online inhibition training task could generate near and mid-transfer effects in the context of response inhibition tasks. As there has been relatively little testing of retention effects in the literature to date, we also examined whether any benefits would persist over a 1-month interval. In a pre-registered, randomised-controlled trial, participants (n = 73) were allocated to either an inhibition training programme (six training sessions of a visual search task with singleton distractor) or a closely matched active control task (that omitted the distractor element). We assessed near transfer to a Flanker task, and mid-transfer to a computerised shoot/don't-shoot task. There was evidence for a near transfer effect, but no evidence for mid-transfer. There was also no evidence that the magnitude of training improvement was related to transfer task performance. This finding adds to the growing body of literature questioning the effectiveness of cognitive training. Given previous positive findings, however, there may still be value in continuing to explore the extent to which cognitive training can capitalise on near or mid-transfer effects for performance optimisation.
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Affiliation(s)
- David J. Harris
- School of Public Health and Sport Sciences, University of Exeter, Exeter, United Kingdom
| | - Mark R. Wilson
- School of Public Health and Sport Sciences, University of Exeter, Exeter, United Kingdom
| | | | | | - Sarah Smith
- Defence Science and Technology Laboratory, Salisbury, United Kingdom
| | - Tom Arthur
- School of Public Health and Sport Sciences, University of Exeter, Exeter, United Kingdom
| | - Kirsty Brock
- School of Public Health and Sport Sciences, University of Exeter, Exeter, United Kingdom
| | - Samuel J. Vine
- School of Public Health and Sport Sciences, University of Exeter, Exeter, United Kingdom
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12
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Li S, O’Hanlon JA, Mattimoe A, Pickford HD, Harwood LA, Wong LL, Robertson J. Two Total Syntheses of Trigoxyphins K and L. Org Lett 2023; 25:7507-7511. [PMID: 37801002 PMCID: PMC10594648 DOI: 10.1021/acs.orglett.3c02796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Indexed: 10/07/2023]
Abstract
Two total syntheses are presented for trigoxyphins K and L, tricyclic terpenoids from Trigonostemon xyphophylloides. The first proceeds via electrophlic cyclization in A/C-ring substrates to close the B ring at C4-C5 and then 1O2-mediated hydroxybutenolide formation to trigoxyphin L, with Luche reduction leading to trigoxyphin K. The second route develops from tetralone ring expansion to a B/C-ring intermediate that, by one-step O-demethylation-lactonization-isomerization, affords trigoxyphin K and then trigoxyphin L following enolate oxygenation.
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Affiliation(s)
- Shuyang Li
- Department
of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield
Road, Oxford OX1 3TA, United Kingdom
| | - Jack A. O’Hanlon
- Department
of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield
Road, Oxford OX1 3TA, United Kingdom
| | - Andrew Mattimoe
- Department
of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield
Road, Oxford OX1 3TA, United Kingdom
| | - Helena D. Pickford
- Department
of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield
Road, Oxford OX1 3TA, United Kingdom
| | - Lucy A. Harwood
- Department
of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield
Road, Oxford OX1 3TA, United Kingdom
| | - Luet L. Wong
- Department
of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford OX1 3QR, United Kingdom
- Oxford
Suzhou Centre for Advanced Research, Ruo Shui Road, Suzhou Industrial Park, Suzhou, Jiangsu 215123, People’s Republic of China
| | - Jeremy Robertson
- Department
of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield
Road, Oxford OX1 3TA, United Kingdom
- Oxford
Suzhou Centre for Advanced Research, Ruo Shui Road, Suzhou Industrial Park, Suzhou, Jiangsu 215123, People’s Republic of China
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13
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G M, Sharma D, Dandela R, Dhayalan V. Synthetic Strategies of N-Heterocyclic Olefin (NHOs) and Their Recent Application of Organocatalytic Reactions and Beyond. Chemistry 2023:e202302106. [PMID: 37605950 DOI: 10.1002/chem.202302106] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 08/23/2023]
Abstract
N-heterocyclic olefin (NHO) derivatives have an electron-rich as well as highly polarized carabon-carbon (C=C) double bond because of the electron-donating nature of nitrogen and sulphur atoms. While NHOs have been developing as novel organocatalysts and ligands for transition-metal complexes in various organic compound syntheses, different research groups are currently interested in preparing imidazole and triazolium-based chiral NHO catalysts. Some of them have been used for enantioselective organic transformations, but were still elusive. N-heterocyclic olefins, the alkylidene derivatives of N-heterocyclic carbenes (NHC), have shown promising results as effective promoters for numerous organic syntheses such as asymmetric catalysis, hydroborylation, hydrosilylation, reduction, CO2 sequestration, alkylation, cycloaddition, polymerization and the ring-opening reaction of aziridine and epoxides, esterification, C-F bond functionalization, amine coupling, trifluoromethyl thiolation, amination etc. NHOs catalysts with suitable structures can serve as a novel class of Lewis/Bronsted bases with strong basicity and high nucleophilicity properties.These facts strongly suggest their enormous chemical potential as sustainable catalysts for a wide variety of reactions in synthetic chemistry. The synthesis of NHOs and their properties are briefly reviewed in this article, along with a summary of the imidazole and triazole core of NHOs' most recent catalytic uses.
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Affiliation(s)
- Mahantesh G
- Department of Chemistry, National Institute of Technology Puducherry, Karaikal, 609609, Union Territory Puducherry, India
| | - Deepika Sharma
- Department of Industrial and Engineering Chemistry, Institute of Chemical Technology, Indian oil Odisha Campus, IIT, Kharagpur extension Centre Mouza Samantpuri, Bhubaneswar, 751013, Odisha, India
| | - Rambabu Dandela
- Department of Industrial and Engineering Chemistry, Institute of Chemical Technology, Indian oil Odisha Campus, IIT, Kharagpur extension Centre Mouza Samantpuri, Bhubaneswar, 751013, Odisha, India
| | - Vasudevan Dhayalan
- Department of Chemistry, National Institute of Technology Puducherry, Karaikal, 609609, Union Territory Puducherry, India
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14
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Ettabib MA, Bowden BM, Liu Z, Marti A, Churchill GM, Gates JC, Zervas MN, Bartlett PN, Wilkinson JS. Grating-incoupled waveguide-enhanced Raman sensor. PLoS One 2023; 18:e0284058. [PMID: 37561713 PMCID: PMC10414634 DOI: 10.1371/journal.pone.0284058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 03/22/2023] [Indexed: 08/12/2023] Open
Abstract
We report a waveguide-enhanced Raman spectroscopy (WERS) platform with alignment-tolerant under-chip grating input coupling. The demonstration is based on a 100-nm thick planar (slab) tantalum pentoxide (Ta2O5) waveguide and the use of benzyl alcohol (BnOH) and its deuterated form (d7- BnOH) as reference analytes. The use of grating couplers simplifies the WERS system by providing improved translational alignment tolerance, important for disposable chips, as well as contributing to improved Raman conversion efficiency. The use of non-volatile, non-toxic BnOH and d7-BnOH as chemical analytes results in easily observable shifts in the Raman vibration lines between the two forms, making them good candidates for calibrating Raman systems. The design and fabrication of the waveguide and grating couplers are described, and a discussion of further potential improvements in performance is presented.
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Affiliation(s)
- Mohamed A. Ettabib
- Zepler Institute for Photonics and Nanoelectronics, University of Southampton, Southampton, United Kingdom
| | - Bethany M. Bowden
- School of Chemistry, University of Southampton, Southampton, United Kingdom
| | - Zhen Liu
- Zepler Institute for Photonics and Nanoelectronics, University of Southampton, Southampton, United Kingdom
| | - Almudena Marti
- School of Chemistry, University of Southampton, Southampton, United Kingdom
| | - Glenn M. Churchill
- Zepler Institute for Photonics and Nanoelectronics, University of Southampton, Southampton, United Kingdom
| | - James C. Gates
- Zepler Institute for Photonics and Nanoelectronics, University of Southampton, Southampton, United Kingdom
| | - Michalis N. Zervas
- Zepler Institute for Photonics and Nanoelectronics, University of Southampton, Southampton, United Kingdom
| | - Philip N. Bartlett
- School of Chemistry, University of Southampton, Southampton, United Kingdom
| | - James S. Wilkinson
- Zepler Institute for Photonics and Nanoelectronics, University of Southampton, Southampton, United Kingdom
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15
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Charlton D, Costa C, Hinder SJ, Watts JF, Bailey MJ. Expanding the Efficacy of Fingermark Enhancement Using ToF-SIMS. Molecules 2023; 28:5687. [PMID: 37570657 PMCID: PMC10419545 DOI: 10.3390/molecules28155687] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/18/2023] [Accepted: 07/19/2023] [Indexed: 08/13/2023] Open
Abstract
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) has been shown to enhance fingermark recovery compared to standard processes used by police forces, but there is no data to show how generally applicable the improvement is. Additionally, ToF-SIMS can be run in either positive or negative ion mode (or both), and there is no data on which mode of operation is most effective at revealing fingerprints. This study aims to fill these gaps by using ToF-SIMS to image fingerprints deposited on two common exhibit-type surfaces (polyethylene and stainless steel) using 10 donors and ageing fingerprints in either ambient, rainwater, or underground for 1 and 5 months. In all, 120 fingerprints were imaged using ToF-SIMS, and each was run in positive and negative modes. A fingerprint expert compared the fingerprint ridge detail produced by the standard process to the ToF-SIMS images. In over 50% of the samples, ToF-SIMS was shown to improve fingerprint ridge detail visualised by the respective standard process for all surfaces tested. In over 90% of the samples, the ridge detail produced by ToF-SIMS was equivalent to standard development across all different ageing and exposure conditions. The data shows that there is a benefit to running the ToF-SIMS in both positive and negative modes, even if no ridge detail was seen in one mode.
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Affiliation(s)
- Deborah Charlton
- Department of Chemistry, University of Surrey, Guildford GU2 7XH, Surrey, UK;
- Fingerprint Development Laboratory, Thames Valley Police, Kidlington OX5 2NX, Oxfordshire, UK
| | - Catia Costa
- Surrey Ion Beam Centre, University of Surrey, Guildford GU2 7XH, Surrey, UK
| | - Steven J. Hinder
- School of Mechanical Engineering Sciences, University of Surrey, Guildford GU2 7XH, Surrey, UK
| | - John F. Watts
- School of Mechanical Engineering Sciences, University of Surrey, Guildford GU2 7XH, Surrey, UK
| | - Melanie J. Bailey
- Department of Chemistry, University of Surrey, Guildford GU2 7XH, Surrey, UK;
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16
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Morgan DC, McDougall L, Knuhtsen A, Jamieson AG. Development of Bifunctional, Raman Active Diyne-Girder Stapled α-Helical Peptides. Chemistry 2023; 29:e202300855. [PMID: 37130830 PMCID: PMC10946806 DOI: 10.1002/chem.202300855] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/02/2023] [Accepted: 05/02/2023] [Indexed: 05/04/2023]
Abstract
Stapled peptides are a unique class of cyclic α-helical peptides that are conformationally constrained via their amino acid side-chains. They have been transformative to the field of chemical biology and peptide drug discovery through addressing many of the physicochemical limitations of linear peptides. However, there are several issues with current chemical strategies to produce stapled peptides. For example, two distinct unnatural amino acids are required to synthesize i, i+7 alkene stapled peptides, leading to high production costs. Furthermore, low purified yields are obtained due to cis/trans isomers produced during ring-closing metathesis macrocyclisation. Here we report the development of a new i, i+7 diyne-girder stapling strategy that addresses these issues. The asymmetric synthesis of nine unnatural Fmoc-protected alkyne-amino acids facilitated a systematic study to determine the optimal (S,S)-stereochemistry and 14-carbon diyne-girder bridge length. Diyne-girder stapled T-STAR peptide 29 was demonstrated to have excellent helicity, cell permeability and stability to protease degradation. Finally, we demonstrate that the diyne-girder constraint is a Raman chromophore with potential use in Raman cell microscopy. Development of this highly effective, bifunctional diyne-girder stapling strategy leads us to believe that it can be used to produce other stapled peptide probes and therapeutics.
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Affiliation(s)
- Danielle C. Morgan
- School of ChemistryAdvanced Research CentreUniversity of Glasgow11 Chapel LaneGlasgowG11 6EWUK
| | - Laura McDougall
- School of ChemistryAdvanced Research CentreUniversity of Glasgow11 Chapel LaneGlasgowG11 6EWUK
| | - Astrid Knuhtsen
- School of ChemistryAdvanced Research CentreUniversity of Glasgow11 Chapel LaneGlasgowG11 6EWUK
| | - Andrew G. Jamieson
- School of ChemistryAdvanced Research CentreUniversity of Glasgow11 Chapel LaneGlasgowG11 6EWUK
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17
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Hadlington L, Binder J, Gardner S, Karanika-Murray M, Knight S. The use of artificial intelligence in a military context: development of the attitudes toward AI in defense (AAID) scale. Front Psychol 2023; 14:1164810. [PMID: 37213385 PMCID: PMC10196355 DOI: 10.3389/fpsyg.2023.1164810] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 04/17/2023] [Indexed: 05/23/2023] Open
Abstract
Introduction The use of artificial intelligence (AI) for national defense is a matter of high societal significance and ongoing public discourse, but very little is known about public acceptance of AI in defense contexts. Currently, there is no reliable and valid measure of attitudes towards AI in defense, and more general attitudinal measures on AI use are unlikely to capture relevant perceptions and opinions. A measure was therefore developed for the assessment of Attitudes towards AI in Defense (AAID), and this work presents the initial validation of this scale. Methods A total of 1,590 participants (aged 19-75, M = 45.7, SD = 16.1) completed a self-report questionnaire which included an initial item pool of 29 attitudinal statements related to the use of AI in defense. An additional general attitude towards AI scale was also included to assess the concurrently validity of the AAID scale. The AAID underwent initial statistical validation via exploratory factor analysis and confirmatory factor analysis to test the underlying structure of the newly developed scale. Results Items reduction and exploratory factor analysis resulted in a final scale consisting of 15 items. A final two factor solution explained 42.52% of the variance (Factor 1 = 22.35%, Factor 2 = 20.17%). Factor 1 was termed "Positive outcomes" and reflected the potential and anticipated consequences of implementing AI in defense. Factor 2 was termed "Negative Outcomes" and reflected the potential negative outcomes for AI in defense. The scale also exhibited acceptable internal reliability and current validity. Discussion The newly developed AAID presents a new measurement tool which has the capacity to assess current attitudes towards AI in defense. Such work is essential if further developments in AI in defense are to continue with the support of the public. However, the work also notes that there are some key concerns and barriers that could block further developments in the area, with further work needed to explore how such anxieties are driven by narratives related to the topic.
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Affiliation(s)
- Lee Hadlington
- Department of Psychology, Nottingham Trent University, Nottingham, United Kingdom
- *Correspondence: Lee Hadlington,
| | - Jens Binder
- Department of Psychology, Nottingham Trent University, Nottingham, United Kingdom
| | - Sarah Gardner
- Department of Psychology, Nottingham Trent University, Nottingham, United Kingdom
| | | | - Sarah Knight
- Exploration Division, Defense Science and Technology Laboratory, Salisbury, United Kingdom
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18
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Blanchard A, Taddeo M. The Ethics of Artificial Intelligence for Intelligence Analysis: a Review of the Key Challenges with Recommendations. Digit Soc 2023; 2:12. [PMID: 37034181 PMCID: PMC10073779 DOI: 10.1007/s44206-023-00036-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 02/09/2023] [Indexed: 04/11/2023]
Abstract
Intelligence agencies have identified artificial intelligence (AI) as a key technology for maintaining an edge over adversaries. As a result, efforts to develop, acquire, and employ AI capabilities for purposes of national security are growing. This article reviews the ethical challenges presented by the use of AI for augmented intelligence analysis. These challenges have been identified through a qualitative systematic review of the relevant literature. The article identifies five sets of ethical challenges relating to intrusion, explainability and accountability, bias, authoritarianism and political security, and collaboration and classification, and offers a series of recommendations targeted at intelligence agencies to address and mitigate these challenges.
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Affiliation(s)
| | - Mariarosaria Taddeo
- The Alan Turing Institute, London, UK
- Oxford Internet Institute, University of Oxford, Oxford, UK
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19
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Smith LD, Chowdhury FT, Peasgood I, Dawkins N, Kattnig DR. Driven Radical Motion Enhances Cryptochrome Magnetoreception: Toward Live Quantum Sensing. J Phys Chem Lett 2022; 13:10500-10506. [PMID: 36332112 PMCID: PMC9677492 DOI: 10.1021/acs.jpclett.2c02840] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
The mechanism underlying magnetoreception has long eluded explanation. A popular hypothesis attributes this sense to the quantum coherent spin dynamics and spin-selective recombination reactions of radical pairs in the protein cryptochrome. However, concerns about the validity of the hypothesis have been raised because unavoidable inter-radical interactions, such as the strong electron-electron dipolar coupling, appear to suppress its sensitivity. We demonstrate that sensitivity can be restored by driving the spin system through a modulation of the inter-radical distance. It is shown that this dynamical process markedly enhances geomagnetic field sensitivity in strongly coupled radical pairs via Landau-Zener-Stückelberg-Majorana transitions between singlet and triplet states. These findings suggest that a "live" harmonically driven magnetoreceptor can be more sensitive than its "dead" static counterpart.
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20
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Ramsay J, Kattnig DR. Radical triads, not pairs, may explain effects of hypomagnetic fields on neurogenesis. PLoS Comput Biol 2022; 18:e1010519. [PMID: 36108063 PMCID: PMC9514667 DOI: 10.1371/journal.pcbi.1010519] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 09/27/2022] [Accepted: 08/27/2022] [Indexed: 12/03/2022] Open
Abstract
Adult hippocampal neurogenesis and hippocampus-dependent cognition in mice have been found to be adversely affected by hypomagnetic field exposure. The effect concurred with a reduction of reactive oxygen species in the absence of the geomagnetic field. A recent theoretical study suggests a mechanistic interpretation of this phenomenon in the framework of the Radical Pair Mechanism. According to this model, a flavin-superoxide radical pair, born in the singlet spin configuration, undergoes magnetic field-dependent spin dynamics such that the pair’s recombination is enhanced as the applied magnetic field is reduced. This model has two ostensible weaknesses: a) the assumption of a singlet initial state is irreconcilable with known reaction pathways generating such radical pairs, and b) the model neglects the swift spin relaxation of free superoxide, which abolishes any magnetic sensitivity in geomagnetic/hypomagnetic fields. We here suggest that a model based on a radical triad and the assumption of a secondary radical scavenging reaction can, in principle, explain the phenomenon without unnatural assumptions, thus providing a coherent explanation of hypomagnetic field effects in biology. The hippocampal region of the brain plays a major role in learning and memory functionality. In male mice, shielding of the Earth’s magnetic field was found to decrease hippocampal neurogenesis, i.e. the formation of new neurons, following from a decrease in levels of reactive oxygen species. In this study, we suggest an explanation in terms of spin dynamics of a three radical system composed of flavin-semiquinone, superoxide and ascorbyl radical. This model agrees with the experimental data whilst retaining realistic parameters for a biological system, unlike the Radical Pair Mechanism.
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Affiliation(s)
- Jess Ramsay
- Living Systems Institute and Department of Physics, University of Exeter, Exeter, Devon, United Kingdom
| | - Daniel R. Kattnig
- Living Systems Institute and Department of Physics, University of Exeter, Exeter, Devon, United Kingdom
- * E-mail:
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21
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Dawson F, Yew WC, Orme B, Markwell C, Ledesma-Aguilar R, Perry JJ, Shortman IM, Smith D, Torun H, Wells G, Unthank MG. Self-Assembled, Hierarchical Structured Surfaces for Applications in (Super)hydrophobic Antiviral Coatings. Langmuir 2022; 38:10632-10641. [PMID: 35977085 PMCID: PMC9434993 DOI: 10.1021/acs.langmuir.2c01579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 08/03/2022] [Indexed: 06/15/2023]
Abstract
A versatile method for the creation of multitier hierarchical structured surfaces is reported, which optimizes both antiviral and hydrophobic (easy-clean) properties. The methodology exploits the availability of surface-active chemical groups while also manipulating both the surface micro- and nanostructure to control the way the surface coating interacts with virus particles within a liquid droplet. This methodology has significant advantages over single-tier structured surfaces, including the ability to overcome the droplet-pinning effect and in delivering surfaces with high static contact angles (>130°) and good antiviral efficacy (log kill >2). In addition, the methodology highlights a valuable approach for the creation of mechanically robust, nanostructured surfaces which can be prepared by spray application using nonspecialized equipment.
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Affiliation(s)
- Frances Dawson
- Northumbria
University, Newcastle
upon Tyne NE1 8ST, U.K.
| | - Wen C. Yew
- Northumbria
University, Newcastle
upon Tyne NE1 8ST, U.K.
| | - Bethany Orme
- Northumbria
University, Newcastle
upon Tyne NE1 8ST, U.K.
| | | | - Rodrigo Ledesma-Aguilar
- Institute
for Multiscale Thermofluids (IMT), School of Engineering, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JL, Scotland, U.K.
| | | | - Ian M. Shortman
- Defence
Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ, U.K.
| | - Darren Smith
- Northumbria
University, Newcastle
upon Tyne NE1 8ST, U.K.
| | - Hamdi Torun
- Northumbria
University, Newcastle
upon Tyne NE1 8ST, U.K.
| | - Gary Wells
- Institute
for Multiscale Thermofluids (IMT), School of Engineering, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JL, Scotland, U.K.
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22
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Abstract
In this report we focus on the definition of autonomous weapons systems (AWS). We provide a comparative analysis of existing official definitions of AWS as provided by States and international organisations, like ICRC and NATO. The analysis highlights that the definitions draw focus on different aspects of AWS and hence lead to different approaches to address the ethical and legal problems of these weapons systems. This approach is detrimental both in terms of fostering an understanding of AWS and in facilitating agreement around conditions of deployment and regulations of their use and, indeed, whether AWS are to be used at all. We draw from the comparative analysis to identify essential aspects of AWS and then offer a definition that provides a value-neutral ground to address the relevant ethical and legal problems. In particular, we identify four key aspects-autonomy; adapting capabilities of AWS; human control; and purpose of use-as the essential factors to define AWS and which are key when considering the related ethical and legal implications.
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Affiliation(s)
- Mariarosaria Taddeo
- Oxford Internet Institute, University of Oxford, Oxford, UK.
- Alan Turing Institute, London, UK.
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23
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De Carvalho Gomes P, Hardy M, Tagger Y, Rickard JJ, Mendes P, Oppenheimer PG. Optimization of Nanosubstrates toward Molecularly Surface-Functionalized Raman Spectroscopy. J Phys Chem C Nanomater Interfaces 2022; 126:13774-13784. [PMID: 36017358 PMCID: PMC9393890 DOI: 10.1021/acs.jpcc.2c03524] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 07/13/2022] [Indexed: 06/15/2023]
Abstract
Diagnostic advancements require continuous developments of reliable analytical sensors, which can simultaneously fulfill many criteria, including high sensitivity and specificity for a broad range of target analytes. Incorporating the highly sensitive attributes of surface-enhanced Raman spectroscopy (SERS) combined with highly specific analyte recognition capabilities via molecular surface functionalization could address major challenges in molecular diagnostics and analytical spectroscopy fields. Herein, we have established a controllable molecular surface functionalization process for a series of textured gold surfaces. To create the molecularly surface-functionalized SERS platforms, self-assembled benzyl-terminated and benzoboroxole-terminated monolayers were used to compare which thicknesses and root-mean-square (RMS) roughness of planar gold produced the most sensitive and specific surfaces. Optimal functionalization was identified at 80 ± 8 nm thickness and 7.2 ± 1.0 nm RMS. These exhibited a considerably higher SERS signal (70-fold) and improved sensitivity for polysaccharides when analyzed using principal component analysis (PCA) and self-organizing maps (SOM). These findings lay the procedure for establishing the optimal substrate specifications as an essential prerequisite for future studies aiming at developing the feasibility of molecular imprinting for SERS diagnostic applications and the subsequent delivery of advanced, highly selective, and sensitive sensing devices and analytical platforms.
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Affiliation(s)
- Paulo De Carvalho Gomes
- School of Chemical
Engineering, College of Engineering and Physical Sciences, University of Birmingham, Birmingham B15 2TT, U.K.
| | - Mike Hardy
- School of Chemical
Engineering, College of Engineering and Physical Sciences, University of Birmingham, Birmingham B15 2TT, U.K.
| | - Yazmin Tagger
- School of Chemical
Engineering, College of Engineering and Physical Sciences, University of Birmingham, Birmingham B15 2TT, U.K.
| | | | - Paula Mendes
- School of Chemical
Engineering, College of Engineering and Physical Sciences, University of Birmingham, Birmingham B15 2TT, U.K.
| | - Pola Goldberg Oppenheimer
- School of Chemical
Engineering, College of Engineering and Physical Sciences, University of Birmingham, Birmingham B15 2TT, U.K.
- Healthcare
Technologies Institute, Translational Medicine, Mindelsohn Way, Birmingham B15 2TH, U.K.
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24
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Berry M, McCabe SM, Sloan-Dennison S, Laing S, Shand NC, Graham D, Faulds K. Tomographic Imaging and Localization of Nanoparticles in Tissue Using Surface-Enhanced Spatially Offset Raman Spectroscopy. ACS Appl Mater Interfaces 2022; 14:31613-31624. [PMID: 35801671 PMCID: PMC9305698 DOI: 10.1021/acsami.2c05611] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
A fundamental question crucial to surface-enhanced spatially offset Raman spectroscopy (SESORS) imaging and implementing it in a clinical setting for in vivo diagnostic purposes is whether a SESORS image can be used to determine the exact location of an object within tissue? To address this question, multiple experimental factors pertaining to the optical setup in imaging experiments using an in-house-built point-collection-based spatially offset Raman spectroscopy (SORS) system were investigated to determine those critical to the three-dimensional (3D) positioning capability of SESORS. Here, we report the effects of the spatial offset magnitude and geometry on locating nanoparticles (NPs) mixed with silica powder as an imaging target through tissue and outline experimental techniques to allow for the correct interpretation of SESORS images to ascertain the correct location of NPs in the two-dimensional x, y-imaging plane at depth. More specifically, the effect of "linear offset-induced image drag" is presented, which refers to a spatial distortion in SESORS images caused by the magnitude and direction of the linear offset and highlight the need for an annular SORS collection geometry during imaging to neutralize these asymmetric effects. Additionally, building on these principles, the concept of "ratiometric SESORS imaging" is introduced for the location of buried inclusions in three dimensions. Together these principles are vital in developing a methodology for the location of surface-enhanced Raman scattering-active inclusions in three dimensions. This approach utilizes the relationship between the magnitude of the spatial offset, the probed depth, and ratiometric analysis of the NP and tissue Raman intensities to ultimately image and spatially discriminate between two distinct NP flavors buried at different depths within a 3D model for the first time. This research demonstrates how to accurately identify multiple objects at depth in tissue and their location using SESORS which addresses a key capability in moving SESORS closer to use in biomedical applications.
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Affiliation(s)
- Matthew
E. Berry
- Department
of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, 99 George Street, Glasgow G1 1RD, U.K.
| | - Samantha M. McCabe
- Department
of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, 99 George Street, Glasgow G1 1RD, U.K.
| | - Sian Sloan-Dennison
- Department
of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, 99 George Street, Glasgow G1 1RD, U.K.
| | - Stacey Laing
- Department
of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, 99 George Street, Glasgow G1 1RD, U.K.
| | - Neil C. Shand
- The
Defence Science and Technology Laboratory (Dstl), Porton Down, Salisbury SP4 0JQ, U.K.
| | - Duncan Graham
- Department
of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, 99 George Street, Glasgow G1 1RD, U.K.
| | - Karen Faulds
- Department
of Pure and Applied Chemistry, Technology and Innovation Centre, University of Strathclyde, 99 George Street, Glasgow G1 1RD, U.K.
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25
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Rumney BM, Morgan SR, Mosselmans JFW, Malik FT, Holden SJ, Parker AR, White N, Lewis PN, Albon J, Meek KM. Characterisation of carapace composition in developing and adult ostracods ( Skogsbergia lerneri) and its potential for biomaterials. Mar Biol 2022; 169:78. [PMID: 35607419 PMCID: PMC9119885 DOI: 10.1007/s00227-022-04047-6] [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] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 03/17/2022] [Indexed: 06/15/2023]
Abstract
The protective carapace of Skogsbergia lerneri, a marine ostracod, is scratch-resistant and transparent. The compositional and structural organisation of the carapace that underlies these properties is unknown. In this study, we aimed to quantify and determine the distribution of chemical elements and chitin within the carapace of adult ostracods, as well as at different stages of ostracod development, to gain insight into its composition. Elemental analyses included X-ray absorption near-edge structure, X-ray fluorescence and X-ray diffraction. Nonlinear microscopy and spectral imaging were performed to determine chitin distribution within the carapace. High levels of calcium (20.3%) and substantial levels of magnesium (1.89%) were identified throughout development. Amorphous calcium carbonate (ACC) was detected in carapaces of all developmental stages, with the polymorph, aragonite, identified in A-1 and adult carapaces. Novel chitin-derived second harmonic generation signals (430/5 nm) were detected. Quantification of relative chitin content within the developing and adult carapaces identified negligible differences in chitin content between developmental stages and adult carapaces, except for the lower chitin contribution in A-2 (66.8 ± 7.6%) compared to A-5 (85.5 ± 10%) (p = 0.03). Skogsbergia lerneri carapace calcium carbonate composition was distinct to other myodocopid ostracods. These calcium polymorphs and ACC are described in other biological transparent materials, and with the consistent chitin distribution throughout S. lerneri development, may imply a biological adaptation to preserve carapace physical properties. Realisation of S. lerneri carapace synthesis and structural organisation will enable exploitation to manufacture biomaterials and biomimetics with huge potential in industrial and military applications.
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Affiliation(s)
- Benjamin M. Rumney
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ UK
| | - Siân R. Morgan
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ UK
- Cardiff Institute of Tissue Engineering and Repair, Cardiff University, Cardiff, UK
| | | | - F. Tegwen Malik
- School of Management, Swansea University, Fabian Way, Swansea, SA1 8EN UK
| | - Simon J. Holden
- DSTL Physical Sciences Group, Platform Systems Division, DSTL Porton Down, Salisbury, SP4 0JQ UK
| | - Andrew R. Parker
- Green Templeton College, University of Oxford, Woodstock Road, Oxford, OX2 0HG UK
| | - Nick White
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ UK
- Vivat Scientia Bioimaging Labs, Cardiff University, Cardiff, CF24 4HQ UK
| | - Philip N. Lewis
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ UK
- Cardiff Institute of Tissue Engineering and Repair, Cardiff University, Cardiff, UK
| | - Julie Albon
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ UK
- Vivat Scientia Bioimaging Labs, Cardiff University, Cardiff, CF24 4HQ UK
- Cardiff Institute of Tissue Engineering and Repair, Cardiff University, Cardiff, UK
| | - Keith M. Meek
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ UK
- Cardiff Institute of Tissue Engineering and Repair, Cardiff University, Cardiff, UK
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26
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Milnes-Smith E, Stone CA, Willis CR, Perkin S. Surface Reconstruction of Fluoropolymers in Liquid Media. Langmuir 2022; 38:4657-4668. [PMID: 35395153 PMCID: PMC9097541 DOI: 10.1021/acs.langmuir.2c00198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/25/2022] [Indexed: 06/14/2023]
Abstract
Surface reconstruction is the rearrangement of atoms or molecules at an interface in response to a stimulus, driven by lowering the overall free energy of the system. Perfluoroalkyl acrylate polymers with short side chains undergo reconstruction at room temperature when exposed to water. Here, we use contact angle aging to examine the liquid- and temperature- dependency of surface reconstruction of plasma polymerized perfluoroalkyl acrylates. We use a first order kinetic model to examine the dynamics of reconstructive processes. Our results show that, above the bulk melting point of the polymers, the contact angles of both polar and nonpolar (hydrocarbon) liquids show a time dependency well fit by the model. We conclude that surface reconstruction can be driven by the preferential segregation of hydrocarbon and fluorocarbon moieties as well as by polar interactions. This has implications in terms of using fluorocarbons to design oleophobic surfaces (and vice versa) and in terms of designing fluorocarbon and/or hydrocarbon surfaces with switchable wettability.
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Affiliation(s)
- Eleanor Milnes-Smith
- Department
of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Corinne A. Stone
- Defence
Science and Technology Laboratory, Porton Down, Salisbury,
Wiltshire SP4 0JQ, United
Kingdom
| | - Colin R. Willis
- Defence
Science and Technology Laboratory, Porton Down, Salisbury,
Wiltshire SP4 0JQ, United
Kingdom
| | - Susan Perkin
- Department
of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
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27
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Rumney BM, Malik FT, Morgan SR, Parker AR, Holden S, Albon J, Lewis PN, Meek KM. The ultrastructural development and 3D reconstruction of the transparent carapace of the ostracod Skogsbergia lerneri. Mar Biol 2022; 169:35. [PMID: 35221378 PMCID: PMC8841342 DOI: 10.1007/s00227-021-04006-7] [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] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
The Skogsbergia lerneri is a marine ostracod which possesses a carapace that is both protective and transparent. Since development of this carapace and how it is maintained in the adult is not known, the aim of this investigation was to carry out an in-depth ultrastructural study of the ostracod carapace at different developmental stages. Standard transmission electron microscopy and novel serial block face scanning electron microscopy (SBF-SEM) were undertaken to discern carapace ultrastructure in both two and three dimensions. Analysis revealed a carapace consisting of the same basic layer structure as other myodocopid ostracods, namely an epicuticle, exocuticle, endocuticle and membranous layer, but with a thinner adult carapace of mean thickness of 19.2 ± 1.78 µm, n = 5. The carapace layers, except for instar 1 ostracods, had similar relative proportions throughout development. The endocuticle and membranous layer thickened through advancing developmental stages due to an increase in calcified crystalline polyhedrons and a greater number of chitinous lamellae in the membranous layer. Crystalline polyhedron dimensions were significantly smaller near the boundary with the membranous layer. The borders between the carapace layers were indistinct; SBF-SEM revealed an abundance of epicuticle projections into the exocuticle and apparent gradual merging at the boundary of the exocuticle and the endocuticle. Here, we discuss how the S. lerneri carapace layer structure has evolved to serve a specific mechanical function, allowing surface protection and rigidity. In addition, we suggest that the lack of pigment and graduated layer boundaries contribute to the transparency of the carapace. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s00227-021-04006-7.
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Affiliation(s)
- Benjamin M. Rumney
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ UK
| | - F. Tegwen Malik
- Swansea University, School of Management, Swansea, SA1 8EN UK
| | - Siân R. Morgan
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ UK
| | - Andrew R. Parker
- Green, Templeton College, University of Oxford, Woodstock Road, Oxford, OX2 0HG UK
| | - Simon Holden
- DSTL Physical Sciences Group, Platform Systems Division, DSTL Porton Down, Salisbury, SP4 0JQ UK
| | - Julie Albon
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ UK
| | - Philip N. Lewis
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ UK
| | - Keith M. Meek
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ UK
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28
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Iwumene NUN, Moseley DF, Pullin RDC, Willis MC. Diverse saturated heterocycles from a hydroacylation/conjugate addition cascade. Chem Sci 2022; 13:1504-1511. [PMID: 35222935 PMCID: PMC8809418 DOI: 10.1039/d1sc06900d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 01/10/2022] [Indexed: 11/21/2022] Open
Abstract
Rhodium-catalyzed hydroacylation using alkynes substituted with pendant nucleophiles, delivers linear α,β-unsaturated enone intermediates with excellent regioselectivity. These adducts are used to construct a broad range of diversely substituted, saturated O-, N- and S-heterocycles in a one-pot process. Judicious choice of cyclisation conditions enabled isolation of O-heterocycles with high levels of diastereoselectivity. A variety of derivatisation reactions are also performed, generating functionalised hydroacylation products. This sequence serves as a general approach for the synthesis of fully saturated heterocycles.
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Affiliation(s)
- Ndidi U N Iwumene
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory Mansfield Road Oxford OX1 3TA UK
| | - Daniel F Moseley
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory Mansfield Road Oxford OX1 3TA UK
| | - Robert D C Pullin
- Vertex Pharmaceuticals (Europe) Ltd 86-88 Jubilee Avenue, Milton Park Abingdon OX14 4RW UK
| | - Michael C Willis
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory Mansfield Road Oxford OX1 3TA UK
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29
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Axford D, Judge PJ, Bada Juarez JF, Kwan TOC, Birch J, Vinals J, Watts A, Moraes I. Two states of a light-sensitive membrane protein captured at room temperature using thin-film sample mounts. Acta Crystallogr D Struct Biol 2022; 78:52-58. [PMID: 34981761 PMCID: PMC8725165 DOI: 10.1107/s2059798321011220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 10/26/2021] [Indexed: 11/25/2022] Open
Abstract
Room-temperature diffraction methods are highly desirable for dynamic studies of biological macromolecules, since they allow high-resolution structural data to be collected as proteins undergo conformational changes. For crystals grown in lipidic cubic phase (LCP), an extruder is commonly used to pass a stream of microcrystals through the X-ray beam; however, the sample quantities required for this method may be difficult to produce for many membrane proteins. A more sample-efficient environment was created using two layers of low X-ray transmittance polymer films to mount crystals of the archaerhodopsin-3 (AR3) photoreceptor and room-temperature diffraction data were acquired. By using transparent and opaque polymer films, two structures, one corresponding to the desensitized, dark-adapted (DA) state and the other to the ground or light-adapted (LA) state, were solved to better than 1.9 Å resolution. All of the key structural features of AR3 were resolved, including the retinal chromophore, which is present as the 13-cis isomer in the DA state and as the all-trans isomer in the LA state. The film-sandwich sample environment enables diffraction data to be recorded at room temperature in both illuminated and dark conditions, which more closely approximate those in vivo. This simple approach is applicable to a wide range of membrane proteins crystallized in LCP and light-sensitive samples in general at synchrotron and laboratory X-ray sources.
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Affiliation(s)
- Danny Axford
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
| | - Peter J. Judge
- Biochemistry Department, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Juan F. Bada Juarez
- Biochemistry Department, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Tristan O. C. Kwan
- National Physical Laboratory, Hampton Road, Teddington, London, United Kingdom
| | - James Birch
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
- Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot OX11 0FA, United Kingdom
| | - Javier Vinals
- Biochemistry Department, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Anthony Watts
- Biochemistry Department, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Isabel Moraes
- National Physical Laboratory, Hampton Road, Teddington, London, United Kingdom
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30
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Hutchings SD, Watchorn J, McDonald R, Jeffreys S, Bates M, Watts S, Kirkman E. Quantification of stroke volume in a simulated healthy volunteer model of traumatic haemorrhage; a comparison of two non-invasive monitoring devices using error grid analysis alongside traditional measures of agreement. PLoS One 2021; 16:e0261546. [PMID: 34941918 PMCID: PMC8699736 DOI: 10.1371/journal.pone.0261546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 12/03/2021] [Indexed: 11/19/2022] Open
Abstract
Introduction Haemorrhage is a leading cause of death following traumatic injury and the early detection of hypovolaemia is critical to effective management. However, accurate assessment of circulating blood volume is challenging when using traditional vital signs such as blood pressure. We conducted a study to compare the stroke volume (SV) recorded using two devices, trans-thoracic electrical bioimpedance (TEB) and supra-sternal Doppler (SSD), against a reference standard using trans- thoracic echocardiography (TTE). Methods A lower body negative pressure (LBNP) model was used to simulate hypovolaemia and in half of the study sessions lower limb tourniquets were applied as these are common in military practice and can potentially affect some haemodynamic monitoring systems. In order to provide a clinically relevant comparison we constructed an error grid alongside more traditional measures of agreement. Results 21 healthy volunteers aged 18–40 were enrolled and underwent 2 sessions of LBNP, with and without lower limb tourniquets. With respect to absolute SV values Bland Altman analysis showed significant bias in both non-tourniquet and tourniquet strands for TEB (-42.5 / -49.6 ml), rendering further analysis impossible. For SSD bias was minimal but percentage error was unacceptably high (35% / 48%). Degree of agreement for dynamic change in SV, assessed using 4 quadrant plots showed a seemingly acceptable concordance rate for both TEB (86% / 93%) and SSD (90% / 91%). However, when results were plotted on an error grid, constructed based on expert clinical opinion, a significant minority of measurement errors were identified that had potential to lead to moderate or severe patient harm. Conclusion Thoracic bioimpedance and suprasternal Doppler both demonstrated measurement errors that had the potential to lead to clinical harm and caution should be applied in interpreting the results in the detection of early hypovolaemia following traumatic injury.
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Affiliation(s)
- Sam D. Hutchings
- Department of Inflammation Biology, School of Immunology and Microbial Sciences, King’s College London, London, United Kingdom
- Academic Department of Military Anaesthesia and Critical Care, Royal Centre for Defence Medicine, Birmingham, United Kingdom
- * E-mail:
| | - Jim Watchorn
- Department of Inflammation Biology, School of Immunology and Microbial Sciences, King’s College London, London, United Kingdom
| | - Rory McDonald
- Academic Department of Military Anaesthesia and Critical Care, Royal Centre for Defence Medicine, Birmingham, United Kingdom
| | - Su Jeffreys
- Academic Department of Military Anaesthesia and Critical Care, Royal Centre for Defence Medicine, Birmingham, United Kingdom
| | - Mark Bates
- Defence Science and Technology Laboratory, Porton Down, Wiltshire, United Kingdom
| | - Sarah Watts
- Defence Science and Technology Laboratory, Porton Down, Wiltshire, United Kingdom
| | - Emrys Kirkman
- Defence Science and Technology Laboratory, Porton Down, Wiltshire, United Kingdom
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31
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Cleverley R, Webb D, Middlemiss S, Duke P, Clare A, Okano K, Harwood C, Aldred N. In Vitro Oxidative Crosslinking of Recombinant Barnacle Cyprid Cement Gland Proteins. Mar Biotechnol (NY) 2021; 23:928-942. [PMID: 34714445 PMCID: PMC8639568 DOI: 10.1007/s10126-021-10076-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 09/23/2021] [Indexed: 06/13/2023]
Abstract
Barnacle adhesion is a focus for fouling-control technologies as well as the development of bioinspired adhesives, although the mechanisms remain very poorly understood. The barnacle cypris larva is responsible for surface colonisation. Cyprids release cement from paired glands that contain proteins, carbohydrates and lipids, although further compositional details are scant. Several genes coding for cement gland-specific proteins were identified, but only one of these showed database homology. This was a lysyl oxidase-like protein (lcp_LOX). LOX-like enzymes have been previously identified in the proteome of adult barnacle cement secretory tissue. We attempted to produce recombinant LOX in E. coli, in order to identify its role in cyprid cement polymerisation. We also produced two other cement gland proteins (lcp3_36k_3B8 and lcp2_57k_2F5). lcp2_57k_2F5 contained 56 lysine residues and constituted a plausible substrate for LOX. While significant quantities of soluble lcp3_36k_3B8 and lcp2_57k_2F5 were produced in E. coli, production of stably soluble lcp_LOX failed. A commercially sourced human LOX catalysed the crosslinking of lcp2_57k_2F5 into putative dimers and trimers, and this reaction was inhibited by lcp3_36k_3B8. Inhibition of the lcp_LOX:lcp2_57k_2F5 reaction by lcp3_36k_3B8 appeared to be substrate specific, with no inhibitory effect on the oxidation of cadaverine by LOX. The results demonstrate a possible curing mechanism for barnacle cyprid cement and, thus, provide a basis for a more complete understanding of larval adhesion for targeted control of marine biofouling and adhesives for niche applications.
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Affiliation(s)
- Robert Cleverley
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, UK
| | - David Webb
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, UK
| | - Stuart Middlemiss
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, UK
| | - Phillip Duke
- Defence Science and Technology Laboratory, Dstl Porton Down, Salisbury, SP4 0JQ, UK
| | - Anthony Clare
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Keiju Okano
- Department of Biotechnology, Akita Prefectural University, Akita, Japan
| | - Colin Harwood
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4AX, UK
| | - Nick Aldred
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK.
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32
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Babcock N, Kattnig DR. Radical Scavenging Could Answer the Challenge Posed by Electron-Electron Dipolar Interactions in the Cryptochrome Compass Model. JACS Au 2021; 1:2033-2046. [PMID: 34841416 PMCID: PMC8611662 DOI: 10.1021/jacsau.1c00332] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Indexed: 06/13/2023]
Abstract
Many birds are endowed with a visual magnetic sense that may exploit magnetosensitive radical recombination processes in the protein cryptochrome. In this widely accepted but unproven model, geomagnetic sensitivity is suggested to arise from variations in the recombination rate of a pair of radicals, whose unpaired electron spins undergo coherent singlet-triplet interconversion in the geomagnetic field by coupling to nuclear spins via hyperfine interactions. However, simulations of this conventional radical pair mechanism (RPM) predicted only tiny magnetosensitivities for realistic conditions because the RPM's directional sensitivity is strongly suppressed by the intrinsic electron-electron dipolar (EED) interactions, casting doubt on its viability as a magnetic sensor. We show how this RPM-suppression problem is overcome in a three-radical system in which a third "scavenger" radical reacts with one member of the primary pair. We use this finding to predict substantial magnetic field effects that exceed those of the RPM in the presence of EED interactions in animal cryptochromes.
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Affiliation(s)
- Nathan
Sean Babcock
- Quantum
Biology Laboratory, Howard University, 2400 Sixth Street NW, Washington District of Columbia, 20059, United States of America
- Living
Systems Institute and Department of Physics University of Exeter, Stocker Road, Exeter, EX4 4QD, United Kingdom
| | - Daniel R. Kattnig
- Living
Systems Institute and Department of Physics University of Exeter, Stocker Road, Exeter, EX4 4QD, United Kingdom
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33
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Slope LN, Daubney OJ, Campbell H, White SA, Peacock AFA. Location-Dependent Lanthanide Selectivity Engineered into Structurally Characterized Designed Coiled Coils. Angew Chem Int Ed Engl 2021; 60:24473-24477. [PMID: 34495573 PMCID: PMC8597134 DOI: 10.1002/anie.202110500] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Indexed: 11/08/2022]
Abstract
Herein we report unprecedented location-dependent, size-selective binding to designed lanthanide (Ln3+ ) sites within miniature protein coiled coil scaffolds. Not only do these engineered sites display unusual Ln3+ selectivity for moderately large Ln3+ ions (Nd to Tb), for the first time we demonstrate that selectivity can be location-dependent and can be programmed into the sequence. A 1 nm linear translation of the binding site towards the N-terminus can convert a selective site into a highly promiscuous one. An X-ray crystal structure, the first of a lanthanide binding site within a coiled coil to be reported, coupled with CD studies, reveal the existence of an optimal radius that likely stems from the structural constraints of the coiled coil scaffold. To the best of our knowledge this is the first report of location-dependent metal selectivity within a coiled coil scaffold, as well as the first report of location-dependent Ln3+ selectivity within a protein.
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Affiliation(s)
- Louise N. Slope
- School of ChemistryUniversity of BirminghamEdgbastonB15 2TTUK
| | | | - Hannah Campbell
- School of ChemistryUniversity of BirminghamEdgbastonB15 2TTUK
| | - Scott A. White
- School of BiosciencesUniversity of BirminghamEdgbastonB15 2TTUK
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34
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Attrill EL, Claydon R, Łapińska U, Recker M, Meaden S, Brown AT, Westra ER, Harding SV, Pagliara S. Individual bacteria in structured environments rely on phenotypic resistance to phage. PLoS Biol 2021; 19:e3001406. [PMID: 34637438 PMCID: PMC8509860 DOI: 10.1371/journal.pbio.3001406] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 09/02/2021] [Indexed: 12/12/2022] Open
Abstract
Bacteriophages represent an avenue to overcome the current antibiotic resistance crisis, but evolution of genetic resistance to phages remains a concern. In vitro, bacteria evolve genetic resistance, preventing phage adsorption or degrading phage DNA. In natural environments, evolved resistance is lower possibly because the spatial heterogeneity within biofilms, microcolonies, or wall populations favours phenotypic survival to lytic phages. However, it is also possible that the persistence of genetically sensitive bacteria is due to less efficient phage amplification in natural environments, the existence of refuges where bacteria can hide, and a reduced spread of resistant genotypes. Here, we monitor the interactions between individual planktonic bacteria in isolation in ephemeral refuges and bacteriophage by tracking the survival of individual cells. We find that in these transient spatial refuges, phenotypic resistance due to reduced expression of the phage receptor is a key determinant of bacterial survival. This survival strategy is in contrast with the emergence of genetic resistance in the absence of ephemeral refuges in well-mixed environments. Predictions generated via a mathematical modelling framework to track bacterial response to phages reveal that the presence of spatial refuges leads to fundamentally different population dynamics that should be considered in order to predict and manipulate the evolutionary and ecological dynamics of bacteria–phage interactions in naturally structured environments. Bacteriophages represent a promising avenue to overcome the current antibiotic resistance crisis, but evolution of phage resistance remains a concern. This study shows that in the presence of spatial refuges, genetic resistance to phage is less of a problem than commonly assumed, but the persistence of genetically susceptible bacteria suggests that eradicating bacterial pathogens from structured environments may require combined phage-antibiotic therapies.
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Affiliation(s)
- Erin L. Attrill
- Living Systems Institute and Biosciences, University of Exeter, Exeter, United Kingdom
| | - Rory Claydon
- SUPA, School of Physics and Astronomy, The University of Edinburgh, United Kingdom
| | - Urszula Łapińska
- Living Systems Institute and Biosciences, University of Exeter, Exeter, United Kingdom
| | - Mario Recker
- Centre for Ecology and Conservation, University of Exeter, Penryn, United Kingdom
| | - Sean Meaden
- Environment and Sustainability Institute and Biosciences, University of Exeter, Penryn, United Kingdom
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Aidan T. Brown
- SUPA, School of Physics and Astronomy, The University of Edinburgh, United Kingdom
| | - Edze R. Westra
- Environment and Sustainability Institute and Biosciences, University of Exeter, Penryn, United Kingdom
| | - Sarah V. Harding
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - Stefano Pagliara
- Living Systems Institute and Biosciences, University of Exeter, Exeter, United Kingdom
- * E-mail:
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35
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Gabriel P, Almehmadi YA, Wong ZR, Dixon DJ. A General Iridium-Catalyzed Reductive Dienamine Synthesis Allows a Five-Step Synthesis of Catharanthine via the Elusive Dehydrosecodine. J Am Chem Soc 2021; 143:10828-10835. [PMID: 34254792 PMCID: PMC8397322 DOI: 10.1021/jacs.1c04980] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Indexed: 02/08/2023]
Abstract
A new reductive strategy for the stereo- and regioselective synthesis of functionalized isoquinuclidines has been developed. Pivoting on the chemoselective iridium(I)-catalyzed reductive activation of β,γ-unsaturated δ-lactams, the efficiently produced reactive dienamine intermediates readily undergo [4 + 2] cycloaddition reactions with a wide range of dienophiles, resulting in the formation of bridged bicyclic amine products. This new synthetic approach was extended to aliphatic starting materials, resulting in the efficient formation of cyclohexenamine products, and readily applied as the key step in the shortest (five-step) total synthesis of vinca alkaloid catharanthine to date, proceeding via its elusive biosynthetic precursor, dehydrosecodine.
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Affiliation(s)
- Pablo Gabriel
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Yaseen A. Almehmadi
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
- Department
of Chemistry, Rabigh College of Science and Arts, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Zeng Rong Wong
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Darren J. Dixon
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
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36
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Wolde-Michael E, Roberts AD, Heyes DJ, Dumanli AG, Blaker JJ, Takano E, Scrutton NS. Design and fabrication of recombinant reflectin-based multilayer reflectors: bio-design engineering and photoisomerism induced wavelength modulation. Sci Rep 2021; 11:14580. [PMID: 34272457 PMCID: PMC8285536 DOI: 10.1038/s41598-021-94042-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 06/18/2021] [Indexed: 11/08/2022] Open
Abstract
The remarkable camouflage capabilities of cephalopods have inspired many to develop dynamic optical materials which exploit certain design principles and/or material properties from cephalopod dermal cells. Here, the angle-dependent optical properties of various single-layer reflectin thin-films on Si wafers are characterized within the UV-Vis-NIR regions. Following this, initial efforts to design, fabricate, and optically characterize a bio-inspired reflectin-based multilayer reflector is described, which was found to conserve the optical properties of single layer films but exhibit reduced angle-dependent visible reflectivity. Finally, we report the integration of phytochrome visible light-induced isomerism into reflectin-based films, which was found to subtly modulate reflectin thin-film reflectivity.
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Affiliation(s)
- Emmanuel Wolde-Michael
- Department of Chemistry, EPSRC/BBSRC Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology, The University of Manchester, Manchester, M1 7DN, UK
| | - Aled D Roberts
- Department of Chemistry, EPSRC/BBSRC Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology, The University of Manchester, Manchester, M1 7DN, UK
| | - Derren J Heyes
- Department of Chemistry, EPSRC/BBSRC Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology, The University of Manchester, Manchester, M1 7DN, UK
| | - Ahu G Dumanli
- Department of Materials and Henry Royce Institute, The University of Manchester, Manchester, M13 9PL, UK
| | - Jonny J Blaker
- Department of Materials and Henry Royce Institute, The University of Manchester, Manchester, M13 9PL, UK
| | - Eriko Takano
- Department of Chemistry, EPSRC/BBSRC Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology, The University of Manchester, Manchester, M1 7DN, UK
| | - Nigel S Scrutton
- Department of Chemistry, EPSRC/BBSRC Future Biomanufacturing Research Hub, Manchester Institute of Biotechnology, The University of Manchester, Manchester, M1 7DN, UK.
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37
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Moore J, Paineau E, Launois P, Shaffer MSP. Continuous Binder-Free Fibers of Pure Imogolite Nanotubes. ACS Appl Mater Interfaces 2021; 13:17940-17947. [PMID: 33830735 PMCID: PMC8153543 DOI: 10.1021/acsami.1c00971] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/26/2021] [Indexed: 06/12/2023]
Abstract
Imogolite nanotubes (INTs) display a range of useful properties and provide an ideal material system to study the assembly of nanomaterials into macroscopic fibers. A method of wet spinning pure, binder-free imogolite fibers has been developed using double-walled germanium imogolite nanotubes. The nanotube aspect ratio can be controlled during the initial synthesis and is critical to the spinning process. Fibers made from short nanotubes (<100 nm) have very low gel strengths, while dopes with longer nanotubes (500-1000 nm) are readily spinnable. The tensile behavior of the resulting imogolite nanotube fibers is strongly influenced by relative humidity (RH), with a modulus of 30 GPa at 10% RH compared to 2.8 GPa at 85% RH, as well as a change in failure mode. This result highlights the importance of inter-nanotube interactions in such assemblies and provides a useful strategy for further exploration. Interestingly, in the absence of a matrix phase, a degree of misorientation appears to improve load transfer between the individual INTs within the porous fiber, likely due to an increase in the number of interparticle contacts. Imogolite nanotubes are an appealing analogue to other nanotube fiber systems, and it is hoped that learnings from this system can also be used to improve carbon nanotube fibers.
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Affiliation(s)
- Joseph
F. Moore
- Department
of Materials, Imperial College London, Exhibition Road, London SW7 2AZ, U.K.
| | - Erwan Paineau
- Université
Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - Pascale Launois
- Université
Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - Milo S. P. Shaffer
- Department
of Materials, Imperial College London, Exhibition Road, London SW7 2AZ, U.K.
- Department
of Chemistry, Imperial College London, Exhibition Road, London SW7 2AZ, U.K.
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38
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Abstract
The way people choose routes through unfamiliar environments provides clues about the underlying representation they use. One way to test the nature of observers' representation is to manipulate the structure of the scene as they move through it and measure which aspects of performance are significantly affected and which are not. We recorded the routes that participants took in virtual mazes to reach previously-viewed targets. The mazes were either physically realizable or impossible (the latter contained 'wormholes' that altered the layout of the scene without any visible change at that moment). We found that participants could usually find the shortest route between remembered objects even in physically impossible environments, despite the gross failures in pointing that an earlier study showed are evident in the physically impossible environment. In the physically impossible conditions, the choice made at a junction was influenced to a greater extent by whether that choice had, in the past, led to the discovery of a target (compared to a shortest-distance prediction). In the physically realizable mazes, on the other hand, junction choices were determined more by the shortest distance to the target. This pattern of results is compatible with the idea of a graph-like representation of space that can include information about previous success or failure for traversing each edge and also information about the distance between nodes. Our results suggest that complexity of the maze may dictate which of these is more important in influencing navigational choices.
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Affiliation(s)
- Alexander Muryy
- School of Psychology and Clinical Language Sciences, University of Reading, Reading, United Kingdom
| | - Andrew Glennerster
- School of Psychology and Clinical Language Sciences, University of Reading, Reading, United Kingdom
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Englert K, Hendi R, Robbs PH, Rees NV, Robinson APG, Tucker JHR. Cisplatin adducts of DNA as precursors for nanostructured catalyst materials. Nanoscale Adv 2020; 2:4491-4497. [PMID: 36132916 PMCID: PMC9417135 DOI: 10.1039/d0na00528b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/17/2020] [Indexed: 06/16/2023]
Abstract
The synthesis and characterisation of novel metal-modified DNA precursors for fuel cell catalyst development are described. Material precursors in the form of metal-DNA complexes were prepared through the reaction of DNA with cisplatin at various loadings and spectroscopically tested to confirm the platinum binding mode and the degree of complexation. The surface morphology of the DNA-metal material was analysed by Scanning Transmission Electron Microscopy (STEM), which revealed the extent of platinum nanocluster formation, with low metal loadings leading to observation of individual platinum atoms. Electrochemical measurements showed a greater electrocatalytic activity for the hydrogen evolution reaction (HER) with increased platinum loadings, shifting the half wave potential, E 1/2, away from the glassy carbon limit towards that of a bulk Pt electrode. This is explained further by Tafel plots, from which a change in the mechanism of the apparent rate limiting step for proton reduction from a Volmer to a Heyrovsky mechanism is postulated as the platinum loading increases.
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Affiliation(s)
- Klaudia Englert
- School of Chemistry, University of Birmingham Edgbaston Birmingham B15 2TT UK
| | - Ruba Hendi
- School of Chemical Engineering, University of Birmingham Edgbaston Birmingham B15 2TT UK
| | - Peter H Robbs
- School of Chemical Engineering, University of Birmingham Edgbaston Birmingham B15 2TT UK
| | - Neil V Rees
- School of Chemical Engineering, University of Birmingham Edgbaston Birmingham B15 2TT UK
| | - Alex P G Robinson
- School of Chemical Engineering, University of Birmingham Edgbaston Birmingham B15 2TT UK
| | - James H R Tucker
- School of Chemistry, University of Birmingham Edgbaston Birmingham B15 2TT UK
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40
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Morgan SR, Paletto L, Rumney B, Malik FT, White N, Lewis PN, Parker AR, Holden S, Meek KM, Albon J. Establishment of long-term ostracod epidermal culture. In Vitro Cell Dev Biol Anim 2020; 56:760-772. [PMID: 33034828 PMCID: PMC7658072 DOI: 10.1007/s11626-020-00508-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 09/09/2020] [Indexed: 02/01/2023]
Abstract
Primary crustacean cell culture was introduced in the 1960s, but to date limited cell lines have been established. Skogsbergia lerneri is a myodocopid ostracod, which has a body enclosed within a thin, durable, transparent bivalved carapace, through which the eye can see. The epidermal layer lines the inner surface of the carapace and is responsible for carapace synthesis. The purpose of the present study was to develop an in vitro epidermal tissue and cell culture method for S. lerneri. First, an optimal environment for the viability of this epidermal tissue was ascertained, while maintaining its cell proliferative capacity. Next, a microdissection technique to remove the epidermal layer for explant culture was established and finally, a cell dissociation method for epidermal cell culture was determined. Maintenance of sterility, cell viability and proliferation were key throughout these processes. This novel approach for viable S. lerneri epidermal tissue and cell culture augments our understanding of crustacean cell biology and the complex biosynthesis of the ostracod carapace. In addition, these techniques have great potential in the fields of biomaterial manufacture, the military and fisheries, for example, in vitro toxicity testing.
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Affiliation(s)
- Siân R Morgan
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
- Cardiff Institute for Tissue Engineering and Repair, School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff, CF10 3NB, UK
| | - Laura Paletto
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
- Cardiff Institute for Tissue Engineering and Repair, School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff, CF10 3NB, UK
- Vivat Scientia Bioimaging Laboratories, School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
| | - Benjamin Rumney
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
- Cardiff Institute for Tissue Engineering and Repair, School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff, CF10 3NB, UK
- Vivat Scientia Bioimaging Laboratories, School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
| | - Farhana T Malik
- Lifescaped, Somerset House, London, WC2R 1LA, UK
- Green Templeton College, University of Oxford, Woodstock Road, Oxford, OX2 6HD, UK
| | - Nick White
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
- Cardiff Institute for Tissue Engineering and Repair, School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff, CF10 3NB, UK
- Vivat Scientia Bioimaging Laboratories, School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
| | - Philip N Lewis
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
- Cardiff Institute for Tissue Engineering and Repair, School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff, CF10 3NB, UK
| | - Andrew R Parker
- Lifescaped, Somerset House, London, WC2R 1LA, UK
- Green Templeton College, University of Oxford, Woodstock Road, Oxford, OX2 6HD, UK
| | - Simon Holden
- Defence Science and Technology Laboratory (DSTL), Porton Down, Salisbury, SP4 0JQ, UK
| | - Keith M Meek
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
- Cardiff Institute for Tissue Engineering and Repair, School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff, CF10 3NB, UK
| | - Julie Albon
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK.
- Cardiff Institute for Tissue Engineering and Repair, School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff, CF10 3NB, UK.
- Vivat Scientia Bioimaging Laboratories, School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK.
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41
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Finnigan W, Roberts AD, Ligorio C, Scrutton NS, Breitling R, Blaker JJ, Takano E. The effect of terminal globular domains on the response of recombinant mini-spidroins to fiber spinning triggers. Sci Rep 2020; 10:10671. [PMID: 32606438 PMCID: PMC7327021 DOI: 10.1038/s41598-020-67703-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 06/11/2020] [Indexed: 12/31/2022] Open
Abstract
Spider silk spidroins consist of long repetitive protein strands, flanked by globular terminal domains. The globular domains are often omitted in recombinant spidroins, but are thought to be essential for the spiders' natural spinning process. Mimicking this spinning process could be an essential step towards producing strong synthetic spider silk. Here we describe the production of a range of mini-spidroins with both terminal domains, and characterize their response to a number of biomimetic spinning triggers. Our results suggest that mini-spidroins which are able to form protein micelles due to the addition of both terminal domains exhibit shear-thinning, a property which native spidroins also show. Furthermore, our data also suggest that a pH drop alone is insufficient to trigger assembly in a wet-spinning process, and must be combined with salting-out for effective fiber formation. With these insights, we applied these assembly triggers for relatively biomimetic wet spinning. This work adds to the foundation of literature for developing improved biomimetic spinning techniques, which ought to result in synthetic silk that more closely approximates the unique properties of native spider silk.
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Affiliation(s)
- William Finnigan
- Department of Chemistry, Manchester Institute of Biotechnology, Manchester Synthetic Biology Research Centre SYNBIOCHEM, The University of Manchester, Manchester, M1 7DN, UK
| | - Aled D Roberts
- Department of Chemistry, Manchester Institute of Biotechnology, Manchester Synthetic Biology Research Centre SYNBIOCHEM, The University of Manchester, Manchester, M1 7DN, UK
| | - Cosimo Ligorio
- Department of Materials, Manchester Institute of Biotechnology, The University of Manchester, Manchester, M1 7DN, UK
| | - Nigel S Scrutton
- Department of Chemistry, Manchester Institute of Biotechnology, Manchester Synthetic Biology Research Centre SYNBIOCHEM, The University of Manchester, Manchester, M1 7DN, UK
| | - Rainer Breitling
- Department of Chemistry, Manchester Institute of Biotechnology, Manchester Synthetic Biology Research Centre SYNBIOCHEM, The University of Manchester, Manchester, M1 7DN, UK
| | - Jonny J Blaker
- Bio-Active Materials Group, Department of Materials, The University of Manchester, Manchester, M13 9PL, UK
| | - Eriko Takano
- Department of Chemistry, Manchester Institute of Biotechnology, Manchester Synthetic Biology Research Centre SYNBIOCHEM, The University of Manchester, Manchester, M1 7DN, UK.
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42
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Passaretti P, Sun Y, Dafforn TR, Oppenheimer PG. Determination and characterisation of the surface charge properties of the bacteriophage M13 to assist bio-nanoengineering. RSC Adv 2020; 10:25385-25392. [PMID: 35517472 PMCID: PMC9055230 DOI: 10.1039/d0ra04086j] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 06/29/2020] [Indexed: 12/13/2022] Open
Abstract
To truly understand the mechanisms behind the supramolecular self-assembly of nanocomponents, the characterisation of their surface properties is crucial. M13 emerged as a practical nanocomponent for bio-nanoassemblies of functional materials and devices, and its popularity is increasing as time goes by. The investigation performed in this study provides important information about the surface charge and the surface area of M13 determined through the comparison of structural data and the measurement of ζ-potential at pH ranging between 2 and 11. The developed methodologies along with the experimental findings can be subsequently exploited as a novel and convenient prediction tool of the total charge of modified versions of M13. This, in turn, will facilitate the design of the self-assembly strategies which would combine the virus building block with other micro and nano components via intermolecular interactions.
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Affiliation(s)
- Paolo Passaretti
- Institute of Cancer and Genomic Science, University of Birmingham Birmingham B15 2TT UK
| | - Yiwei Sun
- School of Engineering and Materials Science, Queen Mary University of London London E1 4NS UK
| | - Timothy R Dafforn
- School of Biosciences, University of Birmingham Birmingham B15 2TT UK
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43
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Harris DJ, Wilson MR, Crowe EM, Vine SJ. Examining the roles of working memory and visual attention in multiple object tracking expertise. Cogn Process 2020; 21:209-222. [PMID: 32016685 PMCID: PMC7203592 DOI: 10.1007/s10339-020-00954-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 01/25/2020] [Indexed: 01/04/2023]
Abstract
When tracking multiple moving targets among visually similar distractors, human observers are capable of distributing attention over several spatial locations. It is unclear, however, whether capacity limitations or perceptual-cognitive abilities are responsible for the development of expertise in multiple object tracking. Across two experiments, we examined the role of working memory and visual attention in tracking expertise. In Experiment 1, individuals who regularly engaged in object tracking sports (soccer and rugby) displayed improved tracking performance, relative to non-tracking sports (swimming, rowing, running) (p = 0.02, ηp2 = 0.163), but no differences in gaze strategy (ps > 0.31). In Experiment 2, participants trained on an adaptive object tracking task showed improved tracking performance (p = 0.005, d = 0.817), but no changes in gaze strategy (ps > 0.07). They did, however, show significant improvement in a working memory transfer task (p < 0.001, d = 0.970). These findings indicate that the development of tracking expertise is more closely linked to processing capacity limits than perceptual-cognitive strategies.
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Affiliation(s)
- David J. Harris
- School of Sport and Health Sciences, University of Exeter, St Luke’s Campus, Exeter, EX1 2LU UK
| | - Mark R. Wilson
- School of Sport and Health Sciences, University of Exeter, St Luke’s Campus, Exeter, EX1 2LU UK
| | - Emily M. Crowe
- Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands
| | - Samuel J. Vine
- School of Sport and Health Sciences, University of Exeter, St Luke’s Campus, Exeter, EX1 2LU UK
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44
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Sterling AJ, Dürr AB, Smith RC, Anderson EA, Duarte F. Rationalizing the diverse reactivity of [1.1.1]propellane through σ-π-delocalization. Chem Sci 2020; 11:4895-4903. [PMID: 34122945 PMCID: PMC8159217 DOI: 10.1039/d0sc01386b] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 04/10/2020] [Indexed: 12/31/2022] Open
Abstract
[1.1.1]Propellane is the ubiquitous precursor to bicyclo[1.1.1]pentanes (BCPs), motifs of high value in pharmaceutical and materials research. The classical Lewis representation of this molecule places an inter-bridgehead C-C bond along its central axis; 'strain relief'-driven cleavage of this bond is commonly thought to enable reactions with nucleophiles, radicals and electrophiles. We propose that this broad reactivity profile instead derives from σ-π-delocalization of electron density in [1.1.1]propellane. Using ab initio and DFT calculations, we show that its reactions with anions and radicals are facilitated by increased delocalization of electron density over the propellane cage during addition, while reactions with cations involve charge transfer that relieves repulsion inside the cage. These results provide a unified framework to rationalize experimental observations of propellane reactivity, opening up opportunities for the exploration of new chemistry of [1.1.1]propellane and related strained systems that are useful building blocks in organic synthesis.
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Affiliation(s)
| | - Alexander B Dürr
- Chemistry Research Laboratory 12 Mansfield Road Oxford OX1 3TA UK
| | - Russell C Smith
- Janssen P.R.D. 3210 Merryfield Row San Diego California CA 92121 USA
| | | | - Fernanda Duarte
- Chemistry Research Laboratory 12 Mansfield Road Oxford OX1 3TA UK
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45
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Isojunno S, Wensveen PJ, Lam FPA, Kvadsheim PH, von Benda-Beckmann AM, Martín López LM, Kleivane L, Siegal EM, Miller PJO. When the noise goes on: received sound energy predicts sperm whale responses to both intermittent and continuous navy sonar. J Exp Biol 2020; 223:jeb219741. [PMID: 32107307 PMCID: PMC7157582 DOI: 10.1242/jeb.219741] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 02/20/2020] [Indexed: 11/20/2022]
Abstract
Anthropogenic noise sources range from intermittent to continuous, with seismic and navy sonar technology moving towards near-continuous transmissions. Continuous active sonar (CAS) may be used at a lower amplitude than traditional pulsed active sonar (PAS), but potentially with greater cumulative sound energy. We conducted at-sea experiments to contrast the effects of navy PAS versus CAS on sperm whale behaviour using animal-attached sound- and movement-recording tags (n=16 individuals) in Norway. Changes in foraging effort and proxies for foraging success and cost during sonar and control exposures were assessed while accounting for baseline variation [individual effects, time of day, bathymetry and blackfish (pilot/killer whale) presence] in generalized additive mixed models (GAMMs). We found no reduction in time spent foraging during exposures to medium-level PAS (MPAS) transmitted at the same peak amplitude as CAS. In contrast, we found similar reductions in foraging during CAS (d.f.=1, F=8.0, P=0.005) and higher amplitude PAS (d.f.=1, F=20.8, P<0.001) when received at similar energy levels integrated over signal duration. These results provide clear support for sound energy over amplitude as the response driver. We discuss the importance of exposure context and the need to measure cumulative sound energy to account for intermittent versus more continuous sources in noise impact assessments.
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Affiliation(s)
- Saana Isojunno
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife KY16 8LB, UK
| | - Paul J Wensveen
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife KY16 8LB, UK
- Faculty of Life and Environmental Sciences, University of Iceland, Askja, Sturlugata 7, 102 Reykjavik, Iceland
| | - Frans-Peter A Lam
- Acoustics and Sonar, Netherlands Organization for Applied Scientific Research (TNO), PO Box 96864 The Hague, 2509 JG, The Netherlands
| | - Petter H Kvadsheim
- Defence Systems Division, Norwegian Defense Research Establishment (FFI), NO-3191 Horten, Norway
| | - Alexander M von Benda-Beckmann
- Acoustics and Sonar, Netherlands Organization for Applied Scientific Research (TNO), PO Box 96864 The Hague, 2509 JG, The Netherlands
| | - Lucía M Martín López
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife KY16 8LB, UK
| | | | - Eilidh M Siegal
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife KY16 8LB, UK
| | - Patrick J O Miller
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife KY16 8LB, UK
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Britt HM, Prakash AS, Appleby S, Mosely JA, Sanderson JM. Lysis of membrane lipids promoted by small organic molecules: Reactivity depends on structure but not lipophilicity. Sci Adv 2020; 6:eaaz8598. [PMID: 32426467 PMCID: PMC7176411 DOI: 10.1126/sciadv.aaz8598] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 01/30/2020] [Indexed: 06/11/2023]
Abstract
Several organic molecules of low molecular weight (<150 Da) are demonstrated to have substantial membrane-lytic potential despite having a low predicted lipophilicity (logD < 1 at neutral pH). In aqueous liposome dispersions, 38 aromatic compounds were tested for their ability to either promote lipid hydrolysis or directly participate in chemical reactions with lipid molecules. Behaviors observed included acyl transfer from the lipid to form a lipidated compound, both with and without concomitant lysolipid formation; increases in the rate of lipid hydrolysis without lipidation; and no reactivity. The variation in activity, including a notably higher activity for heterocycles such as amino-substituted benzimidazoles and indazoles, demonstrates the potential to predict or "design-in" lytic activity once the rules that govern reactivity are better understood. The nature of this chemical instability has significant ramifications for the use or presence of lipids in diverse fields such as materials chemistry, food chemistry, and cell physiology.
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47
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Clarke S, Rigby S, Fay S, Barr A, Tyas A, Gant M, Elgy I. Characterisation of buried blast loading. Proc Math Phys Eng Sci 2020; 476:20190791. [PMID: 32398938 PMCID: PMC7209145 DOI: 10.1098/rspa.2019.0791] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 03/04/2020] [Indexed: 12/03/2022] Open
Abstract
While it is well known that detonation of shallow-buried high explosive charges generally results in above-surface loading which is greatly amplified compared with the same detonation in air, uncertainty persists as to the mechanisms leading to this effect. The work presented in this paper is a systematic investigation into the mechanisms of load transfer in buried blast events. This paper details the results from a parametric study into the mechanisms and magnitudes of load transfer following a shallow-buried explosion, where spatial and temporal load distributions are directly measured on a rigid surface using an array of Hopkinson pressure bars. In particular, the investigation has looked at the influence of both geometrical confinement and geotechnical conditions on the loading. The parametric study was separated into four main threads: the influence of physical confinement; gravimetric moisture content; stand-off distance and depth of burial; and soil material/particle size distribution. This study allows a direct observation of the contributions of each of these distinct parameters, and in particular the ability to discern how each parameter influences the temporal form and spatial distribution of the loading.
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Affiliation(s)
- Sam Clarke
- Department of Civil & Structural Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD, UK
| | - Sam Rigby
- Department of Civil & Structural Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD, UK
| | - Steve Fay
- Department of Civil & Structural Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD, UK
| | - Andrew Barr
- Department of Civil & Structural Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD, UK
| | - Andy Tyas
- Department of Civil & Structural Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD, UK
- Blastech Ltd., The Innovation Centre, 217 Portobello, Sheffield S1 4DP, UK
| | - Matt Gant
- Defence Science and Technology Laboratory (Dstl), Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Ian Elgy
- Defence Science and Technology Laboratory (Dstl), Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
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48
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Roberts AD, Lee JSM, Magaz A, Smith MW, Dennis M, Scrutton NS, Blaker JJ. Hierarchically Porous Silk/Activated-Carbon Composite Fibres for Adsorption and Repellence of Volatile Organic Compounds. Molecules 2020; 25:E1207. [PMID: 32156015 PMCID: PMC7179458 DOI: 10.3390/molecules25051207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/04/2020] [Accepted: 03/05/2020] [Indexed: 11/16/2022] Open
Abstract
Fabrics comprised of porous fibres could provide effective passive protection against chemical and biological (CB) threats whilst maintaining high air permeability (breathability). Here, we fabricate hierarchically porous fibres consisting of regenerated silk fibroin (RSF) and activated-carbon (AC) prepared through two fibre spinning techniques in combination with ice-templating-namely cryogenic solution blow spinning (Cryo-SBS) and cryogenic wet-spinning (Cryo-WS). The Cryo-WS RSF fibres had exceptionally small macropores (as low as 0.1 µm) and high specific surface areas (SSAs) of up to 79 m2·g-1. The incorporation of AC could further increase the SSA to 210 m2·g-1 (25 wt.% loading) whilst also increasing adsorption capacity for volatile organic compounds (VOCs).
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Affiliation(s)
- Aled D. Roberts
- Bio-Active Materials Group, Department of Materials & Henry Royce Institute, The University of Manchester, Manchester M13 9PL, UK; (A.D.R.); (A.M.)
- Future Biomanufacturing Research Hub (FBRH), Manchester Institute of Biotechnology, The University of Manchester, Manchester M1 7DN, UK;
| | - Jet-Sing M. Lee
- Institute for Integrated Cell-Material Sciences, Institute for Advanced Study, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan;
| | - Adrián Magaz
- Bio-Active Materials Group, Department of Materials & Henry Royce Institute, The University of Manchester, Manchester M13 9PL, UK; (A.D.R.); (A.M.)
| | - Martin W. Smith
- Defence Science and Technology Laboratory (Dstl), Porton Down, Salisbury SP4 0JQ, UK; (M.W.S.); (M.D.)
| | - Michael Dennis
- Defence Science and Technology Laboratory (Dstl), Porton Down, Salisbury SP4 0JQ, UK; (M.W.S.); (M.D.)
| | - Nigel S. Scrutton
- Future Biomanufacturing Research Hub (FBRH), Manchester Institute of Biotechnology, The University of Manchester, Manchester M1 7DN, UK;
| | - Jonny J. Blaker
- Bio-Active Materials Group, Department of Materials & Henry Royce Institute, The University of Manchester, Manchester M13 9PL, UK; (A.D.R.); (A.M.)
- Future Biomanufacturing Research Hub (FBRH), Manchester Institute of Biotechnology, The University of Manchester, Manchester M1 7DN, UK;
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49
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Zhou J, Pellegrino A, Heisserer U, Duke PW, Curtis PT, Morton J, Petrinic N, Tagarielli VL. A new technique for tensile testing of engineering materials and composites at high strain rates. Proc Math Phys Eng Sci 2019; 475:20190310. [PMID: 31611727 PMCID: PMC6784402 DOI: 10.1098/rspa.2019.0310] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 08/27/2019] [Indexed: 11/12/2022] Open
Abstract
A new test technique and bespoke apparatus to conduct high strain rate measurements of the tensile response of materials are presented. The new test method is applicable to brittle solids and composites as well as high-performance fibres, yarns and tapes used in composite construction. In this study, the dynamic response of monolithic poly(methyl methacrylate) and unidirectional composites based on Dyneema® tape, Dyneema® SK75 yarn and Kevlar® 49 yarn are explored. The technique allows early force equilibrium and yields valid tensile stress-strain curves, which include part of the elastic material response. The new method also enables investigation of size effects in tape and yarn materials, allowing testing of specimens of arbitrary length.
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Affiliation(s)
- J. Zhou
- Department of Aeronautics, Imperial College London, London SW72AZ, UK
| | - A. Pellegrino
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, UK
| | - U. Heisserer
- DSM Materials Science Center Urmonderbaan 22, 6167 RD Geleen, The Netherlands
| | - P. W. Duke
- Defence Science and Technology Laboratory, Dstl Porton Down, Salisbury SP4 0JQ, UK
| | - P. T. Curtis
- Department of Aeronautics, Imperial College London, London SW72AZ, UK
| | - J. Morton
- Department of Aeronautics, Imperial College London, London SW72AZ, UK
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, UK
| | - N. Petrinic
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, UK
| | - V. L. Tagarielli
- Department of Aeronautics, Imperial College London, London SW72AZ, UK
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, UK
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50
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Burton HE, Cullinan R, Jiang K, Espino DM. Multiscale three-dimensional surface reconstruction and surface roughness of porcine left anterior descending coronary arteries. R Soc Open Sci 2019; 6:190915. [PMID: 31598314 PMCID: PMC6774942 DOI: 10.1098/rsos.190915] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Accepted: 08/07/2019] [Indexed: 05/11/2023]
Abstract
The aim of this study was to investigate the multiscale surface roughness characteristics of coronary arteries, to aid in the development of novel biomaterials and bioinspired medical devices. Porcine left anterior descending coronary arteries were dissected ex vivo, and specimens were chemically fixed and dehydrated for testing. Surface roughness was calculated from three-dimensional reconstructed surface images obtained by optical, scanning electron and atomic force microscopy, ranging in magnification from 10× to 5500×. Circumferential surface roughness decreased with magnification, and microscopy type was found to influence surface roughness values. Longitudinal surface roughness was not affected by magnification or microscopy types within the parameters of this study. This study found that coronary arteries exhibit multiscale characteristics. It also highlights the importance of ensuring consistent microscopy parameters to provide comparable surface roughness values.
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Affiliation(s)
- Hanna E. Burton
- PDR – International Centre for Design and Research, Cardiff Metropolitan University, Cardiff CF5 2YB, UK
- Biomedical Engineering Research Group, Department of Mechanical Engineering, University of Birmingham, Birmingham B15 2TT, UK
| | - Rachael Cullinan
- School of Chemical Engineering, University of Birmingham, Birmingham B15 2TT, UK
| | - Kyle Jiang
- Research Centre for Micro/Nanotechnology, Department of Mechanical Engineering, University of Birmingham, Birmingham B15 2TT, UK
| | - Daniel M. Espino
- Biomedical Engineering Research Group, Department of Mechanical Engineering, University of Birmingham, Birmingham B15 2TT, UK
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