1
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Chen TL, Salij A, Parrish KA, Rasch JK, Zinna F, Brown PJ, Pescitelli G, Urraci F, Aronica LA, Dhavamani A, Arnold MS, Wasielewski MR, di Bari L, Tempelaar R, Goldsmith RH. A 2D chiral microcavity based on apparent circular dichroism. Nat Commun 2024; 15:3072. [PMID: 38594293 PMCID: PMC11004002 DOI: 10.1038/s41467-024-47411-4] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 03/28/2024] [Indexed: 04/11/2024] Open
Abstract
Engineering asymmetric transmission between left-handed and right-handed circularly polarized light in planar Fabry-Pérot (FP) microcavities would enable a variety of chiral light-matter phenomena, with applications in spintronics, polaritonics, and chiral lasing. Such symmetry breaking, however, generally requires Faraday rotators or nanofabricated polarization-preserving mirrors. We present a simple solution requiring no nanofabrication to induce asymmetric transmission in FP microcavities, preserving low mode volumes by embedding organic thin films exhibiting apparent circular dichroism (ACD); an optical phenomenon based on 2D chirality. Importantly, ACD interactions are opposite for counter-propagating light. Consequently, we demonstrated asymmetric transmission of cavity modes over an order of magnitude larger than that of the isolated thin film. Through circular dichroism spectroscopy, Mueller matrix ellipsometry, and simulation using theoretical scattering matrix methods, we characterize the spatial, spectral, and angular chiroptical responses of this 2D chiral microcavity.
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Affiliation(s)
- Tzu-Ling Chen
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, WI, 53706, USA
- Department of Photonics, National Yang Ming Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu, Taiwan
| | - Andrew Salij
- Department of Chemistry, Northwestern University, 2145 Sheridan Rd, Evanston, IL, 60208, USA
| | - Katherine A Parrish
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, WI, 53706, USA
| | - Julia K Rasch
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, WI, 53706, USA
| | - Francesco Zinna
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Giuseppe Moruzzi, 13, Pisa, PI, 56124, Italy
| | - Paige J Brown
- Department of Chemistry, Northwestern University, 2145 Sheridan Rd, Evanston, IL, 60208, USA
| | - Gennaro Pescitelli
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Giuseppe Moruzzi, 13, Pisa, PI, 56124, Italy
| | - Francesco Urraci
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Giuseppe Moruzzi, 13, Pisa, PI, 56124, Italy
| | - Laura A Aronica
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Giuseppe Moruzzi, 13, Pisa, PI, 56124, Italy
| | - Abitha Dhavamani
- Department of Materials Science and Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI, 53706, USA
| | - Michael S Arnold
- Department of Materials Science and Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI, 53706, USA
| | - Michael R Wasielewski
- Department of Chemistry, Northwestern University, 2145 Sheridan Rd, Evanston, IL, 60208, USA
| | - Lorenzo di Bari
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Giuseppe Moruzzi, 13, Pisa, PI, 56124, Italy
| | - Roel Tempelaar
- Department of Chemistry, Northwestern University, 2145 Sheridan Rd, Evanston, IL, 60208, USA.
| | - Randall H Goldsmith
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave, Madison, WI, 53706, USA.
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2
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Zimmerman EA, Irani I, Chen P, Gal-Yam A, Schulze S, Perley DA, Sollerman J, Filippenko AV, Shenar T, Yaron O, Shahaf S, Bruch RJ, Ofek EO, De Cia A, Brink TG, Yang Y, Vasylyev SS, Ben Ami S, Aubert M, Badash A, Bloom JS, Brown PJ, De K, Dimitriadis G, Fransson C, Fremling C, Hinds K, Horesh A, Johansson JP, Kasliwal MM, Kulkarni SR, Kushnir D, Martin C, Matuzewski M, McGurk RC, Miller AA, Morag J, Neil JD, Nugent PE, Post RS, Prusinski NZ, Qin Y, Raichoor A, Riddle R, Rowe M, Rusholme B, Sfaradi I, Sjoberg KM, Soumagnac M, Stein RD, Strotjohann NL, Terwel JH, Wasserman T, Wise J, Wold A, Yan L, Zhang K. The complex circumstellar environment of supernova 2023ixf. Nature 2024; 627:759-762. [PMID: 38538936 DOI: 10.1038/s41586-024-07116-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 01/24/2024] [Indexed: 04/01/2024]
Abstract
The early evolution of a supernova (SN) can reveal information about the environment and the progenitor star. When a star explodes in vacuum, the first photons to escape from its surface appear as a brief, hours-long shock-breakout flare1,2, followed by a cooling phase of emission. However, for stars exploding within a distribution of dense, optically thick circumstellar material (CSM), the first photons escape from the material beyond the stellar edge and the duration of the initial flare can extend to several days, during which the escaping emission indicates photospheric heating3. Early serendipitous observations2,4 that lacked ultraviolet (UV) data were unable to determine whether the early emission is heating or cooling and hence the nature of the early explosion event. Here we report UV spectra of the nearby SN 2023ixf in the galaxy Messier 101 (M101). Using the UV data as well as a comprehensive set of further multiwavelength observations, we temporally resolve the emergence of the explosion shock from a thick medium heated by the SN emission. We derive a reliable bolometric light curve that indicates that the shock breaks out from a dense layer with a radius substantially larger than typical supergiants.
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Affiliation(s)
- E A Zimmerman
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, Israel.
| | - I Irani
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, Israel
| | - P Chen
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, Israel
| | - A Gal-Yam
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, Israel
| | - S Schulze
- The Oskar Klein Centre, Department of Physics, Stockholm University, AlbaNova, Stockholm, Sweden
| | - D A Perley
- Astrophysics Research Institute, Liverpool John Moores University, Liverpool, UK
| | - J Sollerman
- The Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, Stockholm, Sweden
| | - A V Filippenko
- Department of Astronomy, University of California, Berkeley, Berkeley, CA, USA
| | - T Shenar
- Departamento de Astrofísica, Centro de Astrobiología (CSIC-INTA), Madrid, Spain
| | - O Yaron
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, Israel
| | - S Shahaf
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, Israel
| | - R J Bruch
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, Israel
- School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel
| | - E O Ofek
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, Israel
| | - A De Cia
- European Southern Observatory, Garching bei München, Germany
- Department of Astronomy, University of Geneva, Versoix, Switzerland
| | - T G Brink
- Department of Astronomy, University of California, Berkeley, Berkeley, CA, USA
| | - Y Yang
- Department of Astronomy, University of California, Berkeley, Berkeley, CA, USA
- Physics Department and Tsinghua Center for Astrophysics (THCA), Tsinghua University, Beijing, China
| | - S S Vasylyev
- Department of Astronomy, University of California, Berkeley, Berkeley, CA, USA
| | - S Ben Ami
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, Israel
| | - M Aubert
- Université Clermont Auvergne, CNRS/IN2P3, LPC, Clermont-Ferrand, France
| | - A Badash
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, Israel
| | - J S Bloom
- Department of Astronomy, University of California, Berkeley, Berkeley, CA, USA
| | - P J Brown
- Department of Physics and Astronomy, Texas A&M University, College Station, TX, USA
| | - K De
- MIT Kavli Institute for Astrophysics and Space Research, Cambridge, MA, USA
| | - G Dimitriadis
- School of Physics, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland
| | - C Fransson
- The Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, Stockholm, Sweden
| | - C Fremling
- Caltech Optical Observatories, California Institute of Technology, Pasadena, CA, USA
- Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA, USA
| | - K Hinds
- Astrophysics Research Institute, Liverpool John Moores University, Liverpool, UK
| | - A Horesh
- The Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - J P Johansson
- The Oskar Klein Centre, Department of Physics, Stockholm University, AlbaNova, Stockholm, Sweden
| | - M M Kasliwal
- Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA, USA
| | - S R Kulkarni
- Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA, USA
| | - D Kushnir
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, Israel
| | - C Martin
- Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA, USA
| | - M Matuzewski
- Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA, USA
| | - R C McGurk
- W. M. Keck Observatory, Kamuela, HI, USA
| | - A A Miller
- Department of Physics and Astronomy, Northwestern University, Evanston, IL, USA
- Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Northwestern University, Evanston, IL, USA
| | - J Morag
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, Israel
| | - J D Neil
- Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA, USA
| | - P E Nugent
- Department of Astronomy, University of California, Berkeley, Berkeley, CA, USA
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - R S Post
- Post Observatory, Lexington, MA, USA
| | - N Z Prusinski
- Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA, USA
| | - Y Qin
- Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA, USA
| | - A Raichoor
- Department of Astronomy, University of California, Berkeley, Berkeley, CA, USA
| | - R Riddle
- Caltech Optical Observatories, California Institute of Technology, Pasadena, CA, USA
| | - M Rowe
- Department of Physics and Astronomy, Texas A&M University, College Station, TX, USA
| | - B Rusholme
- IPAC, California Institute of Technology, Pasadena, CA, USA
| | - I Sfaradi
- The Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - K M Sjoberg
- Department of Astronomy, Harvard University, Cambridge, MA, USA
- Isaac Newton Group (ING), Santa Cruz de La Palma, Canary Islands, Spain
| | - M Soumagnac
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Physics, Bar-Ilan University, Ramat Gan, Israel
| | - R D Stein
- Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA, USA
| | - N L Strotjohann
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, Israel
| | - J H Terwel
- School of Physics, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland
- Isaac Newton Group (ING), Santa Cruz de La Palma, Canary Islands, Spain
| | - T Wasserman
- Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, Israel
| | - J Wise
- Astrophysics Research Institute, Liverpool John Moores University, Liverpool, UK
| | - A Wold
- IPAC, California Institute of Technology, Pasadena, CA, USA
| | - L Yan
- Caltech Optical Observatories, California Institute of Technology, Pasadena, CA, USA
| | - K Zhang
- Department of Astronomy, University of California, Berkeley, Berkeley, CA, USA
- Department of Astronomy & Astrophysics, University of California, San Diego, La Jolla, CA, USA
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3
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Bradley JM, Coleman AF, Brown PJ, Huang Y, Young RM, Wasielewski MR. Harvesting electrons and holes from photodriven symmetry-breaking charge separation within a perylenediimide photosynthetic model dimer. Proc Natl Acad Sci U S A 2023; 120:e2313575120. [PMID: 37983509 PMCID: PMC10691211 DOI: 10.1073/pnas.2313575120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 10/11/2023] [Indexed: 11/22/2023] Open
Abstract
Understanding how to utilize symmetry-breaking charge separation (SB-CS) offers a path toward increasingly efficient light-harvesting technologies. This process plays a central role in the first step of photosynthesis, in which the dimeric "special pair" of the photosynthetic reaction center enters a coherent SB-CS state after photoexcitation. Previous research on SB-CS in both biological and synthetic chromophore dimers has focused on increasing the efficiency of light-driven processes. In a chromophore dimer undergoing SB-CS, the energy of the radical ion pair product is nearly isoenergetic with that of the lowest excited singlet (S1) state of the dimer. This means that very little energy is lost from the absorbed photon. In principle, the relatively high energy electron and hole generated by SB-CS within the chromophore dimer can each be transferred to adjacent charge acceptors to extend the lifetime of the electron-hole pair, which can increase the efficiency of solar energy conversion. To investigate this possibility, we have designed a bis-perylenediimide cyclophane (mPDI2) covalently linked to a secondary electron donor, peri-xanthenoxanthene (PXX) and a secondary electron acceptor, partially fluorinated naphthalenediimide (FNDI). Upon selective photoexcitation of mPDI2, transient absorption spectroscopy shows that mPDI2 undergoes SB-CS, followed by two secondary charge transfer reactions to generate a PXX•+-mPDI2-FNDI•- radical ion pair having a nearly 3 µs lifetime. This strategy has the potential to increase the efficiency of molecular systems for artificial photosynthesis and photovoltaics.
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Affiliation(s)
- Jillian M. Bradley
- Department of Chemistry, Northwestern University, Evanston, IL60208-3113
- Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, IL60208-3113
| | - Adam F. Coleman
- Department of Chemistry, Northwestern University, Evanston, IL60208-3113
- Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, IL60208-3113
| | - Paige J. Brown
- Department of Chemistry, Northwestern University, Evanston, IL60208-3113
- Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, IL60208-3113
| | - Yuheng Huang
- Department of Chemistry, Northwestern University, Evanston, IL60208-3113
- Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, IL60208-3113
| | - Ryan M. Young
- Department of Chemistry, Northwestern University, Evanston, IL60208-3113
- Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, IL60208-3113
| | - Michael R. Wasielewski
- Department of Chemistry, Northwestern University, Evanston, IL60208-3113
- Paula M. Trienens Institute for Sustainability and Energy, Northwestern University, Evanston, IL60208-3113
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4
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Garci A, Abid S, David AHG, Jones LO, Azad CS, Ovalle M, Brown PJ, Stern CL, Zhao X, Malaisrie L, Schatz GC, Young RM, Wasielewski MR, Stoddart JF. Exciplex Emission and Förster Resonance Energy Transfer in Polycyclic Aromatic Hydrocarbon-Based Bischromophoric Cyclophanes and Homo[2]catenanes. J Am Chem Soc 2023; 145:18391-18401. [PMID: 37565777 DOI: 10.1021/jacs.3c04213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Energy transfer and exciplex emission are not only crucial photophysical processes in many living organisms but also important for the development of smart photonic materials. We report, herein, the rationally designed synthesis and characterization of two highly charged bischromophoric homo[2]catenanes and one cyclophane incorporating a combination of polycyclic aromatic hydrocarbons, i.e., anthracene, pyrene, and perylene, which are intrinsically capable of supporting energy transfer and exciplex formation. The possible coconformations of the homo[2]catenanes, on account of their dynamic behavior, have been probed by Density Functional Theory calculations. The unique photophysical properties of these exotic molecules have been explored by steady-state and time-resolved absorption and fluorescence spectroscopies. The tetracationic pyrene-perylene cyclophane system exhibits emission emanating from a highly efficient Förster resonance energy transfer (FRET) mechanism which occurs in 48 ps, while the octacationic homo[2]catenane displays a weak exciplex photoluminescence following extremely fast (<0.3 ps) exciplex formation. The in-depth fundamental understanding of these photophysical processes involved in the fluorescence of bischromophoric cyclophanes and homo[2]catenanes paves the way for their use in future bioapplications and photonic devices.
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Affiliation(s)
- Amine Garci
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Seifallah Abid
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Arthur H G David
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Leighton O Jones
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Chandra S Azad
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Marco Ovalle
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Paige J Brown
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
- Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Charlotte L Stern
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Xingang Zhao
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Luke Malaisrie
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - George C Schatz
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Ryan M Young
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
- Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Michael R Wasielewski
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
- Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - J Fraser Stoddart
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
- Stoddart Institute of Molecular Science, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
- ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou 311215, China
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5
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Fisher JM, O'Connor JP, Brown PJ, Kim T, Lorenzo ER, Young RM, Wasielewski MR. Two-Dimensional Electronic Spectroscopy Reveals Vibrational Modes Coupled to Charge Transfer in a Julolidine-BODIPY Dyad. J Phys Chem A 2023; 127:2946-2957. [PMID: 36961364 DOI: 10.1021/acs.jpca.3c01122] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
Understanding charge transfer (CT) dynamics in molecular donor-acceptor (D-A) dyads can provide insight into developing efficient D-A molecules for capturing solar energy. Here, we characterize the excited-state evolution of a julolidine-BODIPY (Jul-BD) D-A system with an emissive CT state using time-resolved fluorescence, femtosecond transient absorption, and two-dimensional electronic spectroscopies. Comparison of these results with those from phenyl-BODIPY (Ph-BD) allows us to identify the dynamics at play during CT state formation and its subsequent conversion to either a fully charge-separated or triplet state. Photoexcitation of Jul-BD in tetrahydrofuran results in the formation of an initial emissive CT state that relaxes before fully charge-separating. In contrast, Jul-BD in toluene exhibits similar CT state dynamics, albeit at slower timescales, before decaying to a terminal triplet species. Quantum beat analysis at early times in both solvents shows several vibronic modes, which are corroborated using density functional theory (DFT) calculations. For Ph-BD, a single 220 cm-1 compression mode about the single bond linking the phenyl to BODIPY modulates their orbital overlap. Three active vibronic modes, 147, 174, and 214 cm-1, are found in Jul-BD, regardless of the dielectric constant of the medium. These motions correspond to compression and torsional motions along the single bond joining Jul to BD and are responsible for the evolution of the spontaneous and stimulated emission features in the time-resolved spectroscopic data, which is further supported by time-dependent DFT calculations of the steady-state absorption spectrum of the Jul-BD as a function of increasing D-A dihedral core angle. These findings show how torsional and compression motions can play a pivotal role in intramolecular CT between a D and an A linked by a single bond.
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Affiliation(s)
- Jeremy M Fisher
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern (ISEN), Northwestern University, Evanston, Illinois 60208-3113, United States
| | - James P O'Connor
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern (ISEN), Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Paige J Brown
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern (ISEN), Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Taeyeon Kim
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern (ISEN), Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Emmaline R Lorenzo
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern (ISEN), Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Ryan M Young
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern (ISEN), Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Michael R Wasielewski
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern (ISEN), Northwestern University, Evanston, Illinois 60208-3113, United States
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6
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Lin C, Qi Y, Brown PJ, Williams ML, Palmer JR, Myong M, Zhao X, Young RM, Wasielewski MR. Singlet Fission in Perylene Monoimide Single Crystals and Polycrystalline Films. J Phys Chem Lett 2023; 14:2573-2579. [PMID: 36880847 DOI: 10.1021/acs.jpclett.2c03621] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Singlet fission (SF) is a spin-allowed process in which a photogenerated singlet exciton down-converts into two triplet excitons. Perylene-3,4-dicarboximide (PMI) has singlet and triplet state energies of 2.4 and 1.1 eV, respectively; thus making SF slightly exoergic and providing triplet excitons that have sufficient energy to raise the efficiency of single-junction solar cells by reducing thermalization losses from hot excitons formed when absorbed photons have energies higher than the semiconductor bandgap. However, PMI SF in the solid state has not been studied previously. Here, we show that 2,5-diphenyl-N-(2-ethylhexyl)perylene-3,4-dicarboximide (dp-PMI) crystallizes into a slip-stacked intermolecular morphology favorable for SF. Transient absorption microscopy and spectroscopy show that dp-PMI SF occurs in ≤50 ps in both single crystals and polycrystalline thin films with a triplet yield of 150 ± 20%. Ultrafast SF in the solid state, the high triplet yield, and its photostability make dp-PMI an attractive candidate for SF-enhanced solar cells.
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Affiliation(s)
- Chenjian Lin
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113 United States
| | - Yue Qi
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Paige J Brown
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113 United States
| | - Malik L Williams
- Department of Chemistry, Center for Molecular Quantum Transduction, and Institute for Sustainability and Energy, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Jonathan R Palmer
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113 United States
| | - Michele Myong
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113 United States
| | - Xingang Zhao
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113 United States
| | - Ryan M Young
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113 United States
| | - Michael R Wasielewski
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113 United States
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7
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Qiu Y, Equbal A, Lin C, Huang Y, Brown PJ, Young RM, Krzyaniak MD, Wasielewski MR. Optical Spin Polarization of a Narrow-Linewidth Electron-Spin Qubit in a Chromophore/Stable-Radical System. Angew Chem Int Ed Engl 2023; 62:e202214668. [PMID: 36469535 PMCID: PMC10107609 DOI: 10.1002/anie.202214668] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 11/29/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022]
Abstract
Photoexcited organic chromophores appended to stable radicals can serve as qubit and/or qudit candidates for quantum information applications. 1,6,7,12-Tetra-(4-tert-butylphenoxy)-perylene-3,4 : 9,10-bis(dicarboximide) (tpPDI) linked to a partially deuterated α,γ-bisdiphenylene-β-phenylallyl radical (BDPA-d16 ) was synthesized and characterized by time-resolved optical and electron paramagnetic resonance (EPR) spectroscopies. Photoexcitation of tpPDI-BDPA-d16 results in ultrafast radical-enhanced intersystem crossing to produce a quartet state (Q) followed by formation of a spin-polarized doublet ground state (D0 ). Pulse-EPR experiments confirmed the spin multiplicity of Q and yielded coherence times of Tm =2.1±0.1 μs and 2.8±0.2 μs for Q and D0 , respectively. BDPA-d16 eliminates the dominant 1 H hyperfine couplings, resulting in a single narrow line for both the Q and D0 states, which enhances the spectral resolution needed for good qubit addressability.
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Affiliation(s)
- Yunfan Qiu
- Department of Chemistry, Center for Molecular Quantum Transduction, Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, IL 60208-3113, USA
| | - Asif Equbal
- Department of Chemistry, Center for Molecular Quantum Transduction, Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, IL 60208-3113, USA
| | - Chenjian Lin
- Department of Chemistry, Center for Molecular Quantum Transduction, Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, IL 60208-3113, USA
| | - Yuheng Huang
- Department of Chemistry, Center for Molecular Quantum Transduction, Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, IL 60208-3113, USA
| | - Paige J Brown
- Department of Chemistry, Center for Molecular Quantum Transduction, Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, IL 60208-3113, USA
| | - Ryan M Young
- Department of Chemistry, Center for Molecular Quantum Transduction, Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, IL 60208-3113, USA
| | - Matthew D Krzyaniak
- Department of Chemistry, Center for Molecular Quantum Transduction, Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, IL 60208-3113, USA
| | - Michael R Wasielewski
- Department of Chemistry, Center for Molecular Quantum Transduction, Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, IL 60208-3113, USA
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8
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Garci A, David AHG, Le Bras L, Ovalle M, Abid S, Young RM, Liu W, Azad CS, Brown PJ, Wasielewski MR, Stoddart JF. Thermally Controlled Exciplex Fluorescence in a Dynamic Homo[2]catenane. J Am Chem Soc 2022; 144:23551-23559. [PMID: 36512436 DOI: 10.1021/jacs.2c10591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Motion-induced change in emission (MICE) is a phenomenon that can be employed to develop various types of probes, including temperature and viscosity sensors. Although MICE, arising from the conformational motion in particular compounds, has been studied extensively, this phenomenon has not been investigated in depth in mechanically interlocked molecules (MIMs) undergoing coconformational changes. Herein, we report the investigation of a thermoresponsive dynamic homo[2]catenane incorporating pyrene units and displaying relative circumrotational motions of its cyclophanes as evidenced by variable-temperature 1H NMR spectroscopy and supported by its visualization through molecular dynamics simulations and quantum mechanics calculations. The relative coconformational motions induce a significant change in the fluorescence emission of the homo[2]catenane upon changes in temperature compared with its component cyclophanes. This variation in the exciplex emission of the homo[2]catenane is reversible as demonstrated by four complete cooling and heating cycles. This research opens up possibilities of using the coconformational changes in MIMs-based chromophores for probing fluctuations in temperature which could lead to applications in biomedicine or materials science.
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Affiliation(s)
- Amine Garci
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Arthur H G David
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Laura Le Bras
- Laboratoire Chrono-environnement (UMR 6249), Université de Bourgogne Franche-Comté, 16 route de Gray, 25030 Besançon, France
| | - Marco Ovalle
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Seifallah Abid
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Ryan M Young
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.,Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Wenqi Liu
- Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
| | - Chandra S Azad
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Paige J Brown
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.,Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Michael R Wasielewski
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.,Institute for Sustainability and Energy at Northwestern, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - J Fraser Stoddart
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.,School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia.,Stoddart Institute of Molecular Science, Department of Chemistry, Zhejiang University, Hangzhou 310027, China.,ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou 311215, China
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9
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Qiu Y, Equbal A, Lin C, Huang Y, Brown PJ, Young RM, Krzyaniak MD, Wasielewski MR. Optical Spin Polarization of a Narrow Linewidth Electron Spin Qubit in a Chromophore/Stable‐Radical System. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202214668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Yunfan Qiu
- Northwestern University Chemistry 2145 Sheridan Rd 60208 Evanston, Illinois UNITED STATES
| | - Asif Equbal
- Northwestern University Chemistry 2145 Sheridan Rd 60208 Evanston UNITED STATES
| | - Chenjian Lin
- Northwestern University Chemistry 2145 Sheridan Rd 60208 Evanston UNITED STATES
| | - Yuheng Huang
- Northwestern University Chemistry 2145 Sheridan Rd 60208 Evanston UNITED STATES
| | - Paige J Brown
- Northwestern University Chemistry 2145 Sheridan Rd 60208 Evanston UNITED STATES
| | - Ryan M Young
- Northwestern University Chemistry 2145 Sheridan Rd 60208 Evanston UNITED STATES
| | - Matthew D Krzyaniak
- Northwestern University Chemistry 2145 Sheridan Rd 60208 Evanston UNITED STATES
| | - Michael R. Wasielewski
- Northwestern University Department of Chemistry 2145 N. Sheridan Rd. 60208-3113 Evanston UNITED STATES
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10
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Garci A, Abid S, David AHG, Codesal MD, Đorđević L, Young RM, Sai H, Le Bras L, Perrier A, Ovalle M, Brown PJ, Stern CL, Campaña AG, Stupp SI, Wasielewski MR, Blanco V, Stoddart JF. Aggregation-Induced Emission and Circularly Polarized Luminescence Duality in Tetracationic Binaphthyl-Based Cyclophanes. Angew Chem Int Ed Engl 2022; 61:e202208679. [PMID: 35904930 PMCID: PMC9804443 DOI: 10.1002/anie.202208679] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Indexed: 01/05/2023]
Abstract
Here, we report an approach to the synthesis of highly charged enantiopure cyclophanes by the insertion of axially chiral enantiomeric binaphthyl fluorophores into the constitutions of pyridinium-based macrocycles. Remarkably, these fluorescent tetracationic cyclophanes exhibit a significant AIE compared to their neutral optically active binaphthyl precursors. A combination of theoretical calculations and time-resolved spectroscopy reveal that the AIE originates from limited torsional vibrations associated with the axes of chirality present in the chiral enantiomeric binaphthyl units and the fine-tuning of their electronic landscape when incorporated within the cyclophane structure. Furthermore, these highly charged enantiopure cyclophanes display CPL responses both in solution and in the aggregated state. This unique duality of AIE and CPL in these tetracationic cyclophanes is destined to be of major importance in future development of photonic devices and bio-applications.
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Affiliation(s)
- Amine Garci
- Department of ChemistryNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA
| | - Seifallah Abid
- Department of ChemistryNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA
| | - Arthur H. G. David
- Department of ChemistryNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA
| | - Marcos D. Codesal
- Departamento de Química OrgánicaFacultad de CienciasUnidad de Excelencia de Química Aplicada a Biomedicina y Medioambiente (UEQ)Universidad de Granada (UGR)Avda. Fuente Nueva S/N18071GranadaSpain
| | - Luka Đorđević
- Department of ChemistryNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA,Center for Bio-inspired Energy ScienceNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA
| | - Ryan M. Young
- Department of ChemistryNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA,Institute for Sustainability and Energy at NorthwesternNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA
| | - Hiroaki Sai
- Department of ChemistryNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA,Simpson Querrey Institute for BioNanotechnologyNorthwestern University303 E. Superior StreetChicagoIL 60611USA,Department of Materials Science and EngineeringNorthwestern University2220 Campus DriveEvanstonIL 60208USA
| | - Laura Le Bras
- Laboratoire Chrono-environnement (UMR 6249)Université de Bourgogne Franche-Comté16 route de Gray25030BesançonFrance
| | - Aurélie Perrier
- Chimie Paris TechPSL Research UniversityCNRSInstitute of Chemistry for Life and Health Sciences (i-CLeHS)UMR 806075005ParisFrance,Université Paris Cité75006ParisFrance
| | - Marco Ovalle
- Department of ChemistryNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA
| | - Paige J. Brown
- Department of ChemistryNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA,Institute for Sustainability and Energy at NorthwesternNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA
| | - Charlotte L. Stern
- Department of ChemistryNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA
| | - Araceli G. Campaña
- Departamento de Química OrgánicaFacultad de CienciasUnidad de Excelencia de Química Aplicada a Biomedicina y Medioambiente (UEQ)Universidad de Granada (UGR)Avda. Fuente Nueva S/N18071GranadaSpain
| | - Samuel I. Stupp
- Department of ChemistryNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA,Center for Bio-inspired Energy ScienceNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA,Simpson Querrey Institute for BioNanotechnologyNorthwestern University303 E. Superior StreetChicagoIL 60611USA,Department of Materials Science and EngineeringNorthwestern University2220 Campus DriveEvanstonIL 60208USA,Department of Biomedical EngineeringNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA,Department of MedicineNorthwestern University676N St. Clair StreetChicagoIL 60611USA
| | - Michael R. Wasielewski
- Department of ChemistryNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA,Institute for Sustainability and Energy at NorthwesternNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA
| | - Victor Blanco
- Departamento de Química OrgánicaFacultad de CienciasUnidad de Excelencia de Química Aplicada a Biomedicina y Medioambiente (UEQ)Universidad de Granada (UGR)Avda. Fuente Nueva S/N18071GranadaSpain
| | - J. Fraser Stoddart
- Department of ChemistryNorthwestern University2145 Sheridan RoadEvanstonIL 60208USA,School of ChemistryUniversity of New South WalesSydneyNSW 2052Australia,Stoddart Institute of Molecular ScienceDepartment of ChemistryZhejiang UniversityHangzhou310027China,ZJU-Hangzhou Global Scientific and Technological Innovation CenterHangzhou311215China
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11
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Feng Y, Das PJ, Young RM, Brown PJ, Hornick JE, Weber JA, Seale JSW, Stern CL, Wasielewski MR, Stoddart JF. Alkoxy-Substituted Quadrupolar Fluorescent Dyes. J Am Chem Soc 2022; 144:16841-16854. [PMID: 36083184 DOI: 10.1021/jacs.2c04906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Polar and polarizable π-conjugated organic molecules containing push-pull chromophores have been investigated extensively in the past. Identifying unique backbones and building blocks for fluorescent dyes is a timely exercise. Here, we report the synthesis and characterization of a series of fluorescent dyes containing quadrupolar A-D-A constitutions (where A = acceptor and D = donor), which exhibit fluorescence emission at a variety of different wavelengths. We have investigated the effects of different electron-withdrawing groups, located at both termini of a para-terphenylene backbone, by steady-state UV/vis and fluorescence spectroscopy. Pyridine and substituted pyridinium units are also introduced during the construction of the quadrupolar backbones. Depending on the quadrupolarity, fluorescence emission wavelengths cover from 380 to 557 nm. Time-resolved absorption and emission spectroscopy reveal that the photophysical properties of those quadrupolar dyes result from intramolecular charge transfer. One of the dyes we have investigated is a symmetrical box-like tetracationic cyclophane. Its water-soluble tetrachloride, which is non-cytotoxic to cells up to a loading concentration of 1 μM, has been employed in live-cell imaging. When taken up by cells, the tetrachloride emits a green fluorescence emission without any hint of photobleaching or disruption of normal cell behavior. We envision that our design strategy of modifying molecules through the functionalization of the quadrupolar building blocks as chromophores will lead to future generations of fluorescent dyes in which these A-D-A constitutional fragments are incorporated into more complex molecules and polymers for broader photophysical and biological applications.
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Affiliation(s)
- Yuanning Feng
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Partha Jyoti Das
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Ryan M Young
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.,Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208, United States
| | - Paige J Brown
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.,Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208, United States
| | - Jessica E Hornick
- Chemistry for Life Processes Institutes, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.,Department of Molecular Biosciences, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Jacob A Weber
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - James S W Seale
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Charlotte L Stern
- Integrated Molecular Structure Education and Research Center, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Michael R Wasielewski
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.,Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208, United States
| | - J Fraser Stoddart
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.,School of Chemistry, University of New South Wales, Sydney 2052, New South Wales, Australia.,Stoddart Institute of Molecular Science, Department of Chemistry, Zhejiang University, Hangzhou 310027, China.,ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou 311215, China
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12
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Alzola JM, Tcyrulnikov NA, Brown PJ, Marks TJ, Wasielewski MR, Young RM. Symmetry-Breaking Charge Separation in Phenylene-Bridged Perylenediimide Dimers. J Phys Chem A 2021; 125:7633-7643. [PMID: 34431674 DOI: 10.1021/acs.jpca.1c05100] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Perylenediimides (PDIs) are important molecular building blocks that are being investigated for their applicability in optoelectronic technologies. Covalently linking multiple PDI acceptors at the 2,5,8,11 (headland) positions adjacent to the PDI carbonyl groups is reported to yield higher power conversion efficiencies in photovoltaic cells relative to PDI acceptors linked at the 1,6,7,12 (bay) positions. While the photophysical properties of PDIs linked via the bay positions have been investigated extensively, those linked at the headland positions have received far less attention. We showed previously that symmetry-breaking charge separation (SB-CS) in PDIs hold promise as a strategy for increasing photovoltaic efficiency. Here we use transient absorption and emission spectroscopies to investigate the competition between SB-CS, fluorescence, and internal conversion in three related PDI dimers linked at the headland positions with o-, m-, and p-phenylene moieties: o-PDI2, m-PDI2, and p-PDI2, respectively. It is found that o-PDI2 supports SB-CS yielding PDI•+-PDI•-, which is in equilibrium with the o-PDI2 first excited state in a polar solvent (CH2Cl2) while m-PDI2 and p-PDI2 exhibit accelerated internal conversion due to the motion of the linker along with subnanosecond intersystem crossing (ISC). Electronic coupling and structural dynamics are shown to play a significant role, with o-PDI2 being the only member of the series that exhibits significant through-bond interchromophore coupling. The pronounced o-PDI2 steric congestion prevents the free internal rotation that leads to rapid deactivation of the excited state in the other dimers.
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Affiliation(s)
- Joaquin M Alzola
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Nikolai A Tcyrulnikov
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Paige J Brown
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Tobin J Marks
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Michael R Wasielewski
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Ryan M Young
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
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13
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Fatania K, Brown PJ, Xie C, McDermott G, Callister MEJ, Graham R, Subesinghe M, Gleeson FV, Scarsbrook AF. Multi-observer concordance and accuracy of the British Thoracic Society scale and other visual assessment qualitative criteria for solid pulmonary nodule assessment using FDG PET-CT. Clin Radiol 2020; 75:878.e21-878.e28. [PMID: 32709393 DOI: 10.1016/j.crad.2020.06.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 06/24/2020] [Indexed: 10/23/2022]
Abstract
AIM To compare the interobserver reliability and diagnostic accuracy of the British Thoracic Society (BTS) scale and other visual assessment criteria in the context of 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET)-computed tomography (CT) evaluation of solid pulmonary nodules (SPNs). MATERIALS AND METHODS Fifty patients who underwent FDG PET-CT for assessment of a SPN were identified. Seven reporters with varied experience at four centres graded FDG uptake visually using the British Thoracic Society (BTS) four-point scale. Five reporters also scored SPNs according to three- and five-point visual assessment scales and using semi-quantitative assessment (maximum standardised uptake value [SUVmax]). Interobserver reliability was assessed with the intra-class correlation coefficient (ICC) and weighted Cohen's kappa (κ). Diagnostic performance was evaluated by receiver operator characteristic (ROC) analysis. RESULTS Good interobserver reliability was demonstrated with the BTS scale (ICC=0.78, 95% confidence interval [CI]: 0.69-0.85) and five-point scale (ICC=0.78, 95 CI 0.68-0.86), whilst the three-point scale demonstrated moderate reliability (ICC=0.70, 95% CI: 0.59-0.80). Almost perfect agreement was achieved between two consultants (κ=0.85), and substantial agreement between two other consultants (κ=0.78) using the BTS scale. ROC curves for the BTS and five-point scales demonstrated equivalent accuracy (BTS area under the ROC curve [AUC]=0.768; five-point AUC=0.768). SUVmax was no more accurate compared to the BTS scale (SUVmax AUC=0.794; BTS AUC=0.768, p=0.43). CONCLUSIONS The BTS scale can be applied reliably by reporters with varied levels of PET-CT reporting experience, across different centres and has a diagnostic performance that is not surpassed by alternative scales.
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Affiliation(s)
- K Fatania
- Department of Radiology, Leeds Teaching Hospitals NHS Trust, Leeds, UK.
| | - P J Brown
- Department of Radiology, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - C Xie
- Department of Radiology, Oxford University Hospitals Foundation Trust, Oxford, UK
| | - G McDermott
- Department of Medical Physics, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - M E J Callister
- Department of Respiratory Medicine, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - R Graham
- Department of Radiology, Royal United Hospitals Bath NHS Foundation Trust, Bath, UK
| | - M Subesinghe
- King's College London & Guy's and St. Thomas' PET Centre, St Thomas' Hospital, London, UK; Department of Cancer Imaging, School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - F V Gleeson
- Department of Radiology, Oxford University Hospitals Foundation Trust, Oxford, UK
| | - A F Scarsbrook
- Department of Radiology, Leeds Teaching Hospitals NHS Trust, Leeds, UK; Leeds Institute of Research at St James', University of Leeds, UK
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14
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Brown PJ, Zhong J, Frood R, Currie S, Gilbert A, Appelt AL, Sebag-Montefiore D, Scarsbrook A. Prediction of outcome in anal squamous cell carcinoma using radiomic feature analysis of pre-treatment FDG PET-CT. Eur J Nucl Med Mol Imaging 2019; 46:2790-2799. [PMID: 31482428 PMCID: PMC6879433 DOI: 10.1007/s00259-019-04495-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [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: 05/08/2019] [Accepted: 08/20/2019] [Indexed: 12/22/2022]
Abstract
PURPOSE Incidence of anal squamous cell carcinoma (ASCC) is increasing, with curative chemoradiotherapy (CRT) as the primary treatment of non-metastatic disease. A significant proportion of patients have locoregional treatment failure (LRF), but distant relapse is uncommon. Accurate prognostication of progression-free survival (PFS) would help personalisation of CRT regimens. The study aim was to evaluate novel imaging pre-treatment features, to prognosticate for PFS in ASCC. METHODS Consecutive patients with ASCC treated with curative intent at a large tertiary referral centre who underwent pre-treatment FDG-PET/CT were included. Radiomic feature extraction was performed using LIFEx software on baseline FDG-PET/CT. Outcome data (PFS) was collated from electronic patient records. Elastic net regularisation and feature selection were used for logistic regression model generation on a randomly selected training cohort and applied to a validation cohort using TRIPOD guidelines. ROC-AUC analysis was used to compare performance of a regression model encompassing standard clinical prognostic factors (age, sex, tumour and nodal stage-model A), a radiomic feature model (model B) and a combined radiomic/clinical model (model C). RESULTS A total of 189 patients were included in the study, with 145 in the training cohort and 44 in the validation cohort. Median follow-up was 35.1 and 37. 9 months, respectively for each cohort, with 70.3% and 68.2% reaching this time-point with PFS. GLCM entropy (a measure of randomness of distribution of co-occurring pixel grey-levels), NGLDM busyness (a measure of spatial frequency of changes in intensity between nearby voxels of different grey-level), minimum CT value (lowest HU within the lesion) and SMTV (a standardized version of MTV) were selected for inclusion in the prognostic model, alongside tumour and nodal stage. AUCs for performance of model A (clinical), B (radiomic) and C (radiomic/clinical) were 0.6355, 0.7403, 0.7412 in the training cohort and 0.6024, 0.6595, 0.7381 in the validation cohort. CONCLUSION Radiomic features extracted from pre-treatment FDG-PET/CT in patients with ASCC may provide better PFS prognosis than conventional staging parameters. With external validation, this might be useful to help personalise CRT regimens in the future.
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Affiliation(s)
- P J Brown
- Department of Clinical Radiology, Lincoln Wing, Leeds Teaching Hospitals NHS Trust, St James's University Hospital, Beckett Street, Leeds, LS9 7TF, UK.
| | - J Zhong
- Department of Clinical Radiology, Lincoln Wing, Leeds Teaching Hospitals NHS Trust, St James's University Hospital, Beckett Street, Leeds, LS9 7TF, UK
| | - R Frood
- Department of Clinical Radiology, Lincoln Wing, Leeds Teaching Hospitals NHS Trust, St James's University Hospital, Beckett Street, Leeds, LS9 7TF, UK
| | - S Currie
- Department of Clinical Radiology, Lincoln Wing, Leeds Teaching Hospitals NHS Trust, St James's University Hospital, Beckett Street, Leeds, LS9 7TF, UK
- Radiotherapy Research Group, Leeds Institute of Medical Research at St James's, Faculty of Medicine & Health, University of Leeds, Leeds, UK
| | - A Gilbert
- Radiotherapy Research Group, Leeds Institute of Medical Research at St James's, Faculty of Medicine & Health, University of Leeds, Leeds, UK
- Department of Clinical Oncology, Bexley Wing, Leeds Teaching Hospitals NHS Trust, St James's University Hospital, Beckett Street, Leeds, LS9 7TF, UK
| | - A L Appelt
- Radiotherapy Research Group, Leeds Institute of Medical Research at St James's, Faculty of Medicine & Health, University of Leeds, Leeds, UK
- Department of Clinical Oncology, Bexley Wing, Leeds Teaching Hospitals NHS Trust, St James's University Hospital, Beckett Street, Leeds, LS9 7TF, UK
| | - D Sebag-Montefiore
- Radiotherapy Research Group, Leeds Institute of Medical Research at St James's, Faculty of Medicine & Health, University of Leeds, Leeds, UK
- Department of Clinical Oncology, Bexley Wing, Leeds Teaching Hospitals NHS Trust, St James's University Hospital, Beckett Street, Leeds, LS9 7TF, UK
| | - A Scarsbrook
- Department of Clinical Radiology, Lincoln Wing, Leeds Teaching Hospitals NHS Trust, St James's University Hospital, Beckett Street, Leeds, LS9 7TF, UK
- Radiotherapy Research Group, Leeds Institute of Medical Research at St James's, Faculty of Medicine & Health, University of Leeds, Leeds, UK
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15
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Nelson KJ, Brown PJ, Rudel HE, Takematsu K. Divergent excited state proton transfer reactions of bifunctional photoacids 1-ammonium-2-naphthol and 3-ammonium-2-naphthol in water and methanol. Phys Chem Chem Phys 2019; 21:24383-24392. [PMID: 31663559 DOI: 10.1039/c9cp05269k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This paper highlights the challenge of predicting the excited state proton transfer (ESPT) reactions of small organic compounds with multiple proton transfer sites. Aminonaphthols, naphthalene compounds with both hydroxyl and amino substituents, can be viewed as a combination of two monoprotic photoacids, naphthol and naphthylammonium. Here, the ESPT reactions of 3-ammonium-2-naphthol (3N2OH) and 1-ammonium-2-naphthol (1N2OH) were studied in water and methanol using a combination of steady-state and time-correlated single-photon counting emission spectroscopy. For 3N2OH, ESPT was observed at the OH site in water but at neither of the sites in methanol; for 1N2OH, ESPT was observed at both the OH and NH3+ sites in water but only at the NH3+ site in methanol. Evidence of ESPT at the NH3+ site is limited for aminonaphthols. The divergent dynamics of 3N2OH and 1N2OH in water and methanol are discussed; dependent on the substitution and solvent, the ESPT reactions were analysed within the frameworks of reference photoacids 2-naphthol and 1-naphthylammonium. The application of crown ether and salt to control the release of select protons in non-aqueous media is also discussed.
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Affiliation(s)
- Kacie J Nelson
- Department of Chemistry, Bowdoin College, Brunswick, ME 04011, USA.
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16
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Holper L, Lan MJ, Brown PJ, Sublette ME, Burke A, Mann JJ. Brain cytochrome-c-oxidase as a marker of mitochondrial function: A pilot study in major depression using NIRS. Depress Anxiety 2019; 36:766-779. [PMID: 31111623 PMCID: PMC6716511 DOI: 10.1002/da.22913] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Revised: 03/12/2019] [Accepted: 04/22/2019] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Brain mitochondrial dysfunction is implicated in the pathophysiology of mood disorders. Brain cytochrome-c-oxidase (COX) activity is associated with the mitochondrial function. Near-infrared spectroscopy (NIRS) noninvasively measures oxidized COX (oxCOX) and tissue oxygenation index (TOI) reflecting cerebral blood flow and oxygenation. METHODS oxCOX and TOI were assessed in prefrontal cortex (Fp1/2, Brodmann area 10) in patients in a major depressive episode (N = 13) with major depressive disorder (MDD; N = 7) and bipolar disorder (BD; N = 6) compared with the controls (N = 10). One patient with MDD and all the patients with BD were taking medications. Computational modeling estimated oxCOX and TOI related indices of mitochondrial function and cerebral blood flow, respectively. RESULTS oxCOX was lower in patients than controls (p = .014) correlating inversely with depression severity (r = -.72; p = .006), driven primarily by lower oxCOX in BD compared with the controls. Computationally modeled mitochondrial parameters of the electron transport chain, such as the nicotinamide adenine dinucleotide ratio (NAD+ /NADH; p = .001) and the proton leak rate across the inner mitochondrial membrane (klk2 ; p = .008), were also lower in patients and correlated inversely with depression severity. No such effects were found for TOI. CONCLUSIONS In this pilot study, oxCOX and related mitochondrial parameters assessed by NIRS indicate an abnormal cerebral metabolic state in mood disorders proportional to depression severity, potentially providing a biomarker of antidepressant effect. Because the effect was driven by the medicated BD group, findings need to be evaluated in a larger, medication-free population.
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Affiliation(s)
- L Holper
- Division of Molecular Imaging and Neuropathology, Columbia University and New York State Psychiatric Institute, New York, NY,Department of Psychiatry, Psychotherapy, and Psychosomatics, University Hospital of Psychiatry Zurich, 8032 Zurich, Switzerland
| | - MJ Lan
- Division of Molecular Imaging and Neuropathology, Columbia University and New York State Psychiatric Institute, New York, NY
| | - PJ Brown
- Geriatric Psychiatry, Columbia University College of Physicians and Surgeons and New York State Psychiatric Institute, New York, NY
| | - ME Sublette
- Division of Molecular Imaging and Neuropathology, Columbia University and New York State Psychiatric Institute, New York, NY
| | - A Burke
- Division of Molecular Imaging and Neuropathology, Columbia University and New York State Psychiatric Institute, New York, NY
| | - JJ Mann
- Division of Molecular Imaging and Neuropathology, Columbia University and New York State Psychiatric Institute, New York, NY,Department of Radiology, Columbia University, New York, NY
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Brown PJ, Hyland R, Quyn AJ, West NP, Sebag-Montefiore D, Jayne D, Sagar P, Tolan DJ. Current concepts in imaging for local staging of advanced rectal cancer. Clin Radiol 2019; 74:623-636. [PMID: 31036310 DOI: 10.1016/j.crad.2019.03.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 03/22/2019] [Indexed: 12/20/2022]
Abstract
Imaging of rectal cancer has an increasingly pivotal role in the diagnosis, staging, and treatment stratification of patients with the disease. This is particularly true for advanced rectal cancers where magnetic resonance imaging (MRI) findings provide essential information that can change treatment. In this review we describe the rationale for the current imaging standards in advanced rectal cancer for both morphological and functional imaging on the baseline staging and reassessment studies. In addition the clinical implications and future methods by which radiologists may improve these are outlined relative to TNM8.
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Affiliation(s)
- P J Brown
- Department of Clinical Radiology, Lincoln Wing, St James' University Hospital, Leeds Teaching Hospitals NHS Trust, Beckett Street, Leeds, LS9 7TF, UK.
| | - R Hyland
- Department of Clinical Radiology, Lincoln Wing, St James' University Hospital, Leeds Teaching Hospitals NHS Trust, Beckett Street, Leeds, LS9 7TF, UK
| | - A J Quyn
- Department of General Surgery, Lincoln Wing, St James' University Hospital, Leeds Teaching Hospitals NHS Trust, Beckett Street, Leeds, LS9 7TF, UK
| | - N P West
- Pathology and Data Analytics, Leeds Institute of Medical Research at St James's, University of Leeds, Welcome Trust Brenner Building, St James's University Hospital, Leeds, LS9 7TF, UK
| | - D Sebag-Montefiore
- Department of Clinical Oncology, Bexley Wing, St James' University Hospital, Leeds Teaching Hospitals NHS Trust, Beckett Street, Leeds, LS9 7TF, UK
| | - D Jayne
- Department of General Surgery, Lincoln Wing, St James' University Hospital, Leeds Teaching Hospitals NHS Trust, Beckett Street, Leeds, LS9 7TF, UK
| | - P Sagar
- Department of General Surgery, Lincoln Wing, St James' University Hospital, Leeds Teaching Hospitals NHS Trust, Beckett Street, Leeds, LS9 7TF, UK
| | - D J Tolan
- Department of Clinical Radiology, Lincoln Wing, St James' University Hospital, Leeds Teaching Hospitals NHS Trust, Beckett Street, Leeds, LS9 7TF, UK
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18
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Cotter LF, Brown PJ, Nelson RC, Takematsu K. Divergent Hammett Plots of the Ground- and Excited-State Proton Transfer Reactions of 7-Substituted-2-Naphthol Compounds. J Phys Chem B 2019; 123:4301-4310. [PMID: 31021637 DOI: 10.1021/acs.jpcb.9b01295] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The rational design of photoacids requires accessible predictive models of the electronic effect of functional groups on chemical templates of interest. Here, the effect of substituents on the photoacidity and excited-state proton transfer (PT) pathways of prototype 2-naphthol (2OH) at the symmetric C7 position was investigated through photochemical and computational studies of 7-amino-2-naphthol (7N2OH) and 7-methoxy-2-naphthol (7OMe2OH). Time-resolved emission experiments of 7N2OH revealed that the presence of an electron-withdrawing versus electron-donating group (EWG vs EDG, NH3+ vs NH2) led to a drastic decline in photoacidity: p Ka* = 1.1 ± 0.2 vs 9.6 ± 0.2. Time-dependent density functional theory calculations with explicit water molecules confirmed that the excited neutral state (x = NH2) is greatly stabilized by water, with equation-of-motion coupled cluster singles and doubles calculations supporting potential mixing between the La and Lb states. Similar suppression of photoacidity, however, was not observed for 7OMe2OH with EDG OCH3, p Ka* = 2.7 ± 0.1. Hammett plots of the ground- and excited-state PT reactions of substituted 7-x-2OH compounds (x = CN, NH3+, H, CH3, OCH3, OH, and NH2) vs Hammett parameters σp showed breaks in the linearity between the EDG and EWG regions: ρ ∼ 0 vs 1.14 and ρ* ∼ 0 vs 3.86. The divergent acidic behavior most likely arises from different mixing mechanisms of the lowest Lb state with the La and possible Bb states upon substitution of naphthalene in water.
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Affiliation(s)
- Laura F Cotter
- Department of Chemistry , Bowdoin College , Brunswick , Maine 04011 , United States
| | - Paige J Brown
- Department of Chemistry , Bowdoin College , Brunswick , Maine 04011 , United States
| | - Ryan C Nelson
- Department of Chemistry , Bowdoin College , Brunswick , Maine 04011 , United States
| | - Kana Takematsu
- Department of Chemistry , Bowdoin College , Brunswick , Maine 04011 , United States
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Brown PJ, Rossington H, Taylor J, Lambregts DMJ, Morris EJA, West NP, Quirke P, Tolan D. Radiologist and multidisciplinary team clinician opinions on the quality of MRI rectal cancer staging reports: how are we doing? Clin Radiol 2019; 74:637-642. [PMID: 31084973 DOI: 10.1016/j.crad.2019.04.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
AIM To evaluate the current opinion of magnetic resonance imaging (MRI) reports amongst specialist clinicians involved in colorectal cancer multidisciplinary teams (CRC MDTs). MATERIALS AND METHODS Active participants at 16 UK CRC MDTs across a population of 5.7 million were invited to complete a questionnaire, this included 22 closed and three open questions. Closed questions used ordinal (Likert) scales to judge the subjective inclusion of tumour descriptors and impressions on the clarity and consistency of the MRI report. Open (free-text) questions allowed overall feedback and suggestions. RESULTS A total of 69 participants completed the survey (21 radiologists and 48 other CRC MDT clinicians). Both groups highlighted that reports commonly omit the status of the circumferential resection margin (CRM; 83% versus 81% inclusion, other clinicians and radiologists, respectively, p>0.05), presence or absence of extra-mural venous invasion (EMVI; 67% versus 57% inclusion, p>0.05), and lymph node status (90% inclusion in both groups). Intra-radiologist agreement across MRI examinations is reported as 75% by other clinicians. Free-text comments included suggestions for template-style reports. CONCLUSION Both groups recognise a proportion of MRI reports are suboptimal with key tumour descriptors omitted. There are also concerns around the presentation style of MRI reports and inter- and intra-radiologist report variability. The widespread implementation of standardised report templates may improve completeness and clarity of MRI reports for rectal cancer and thus clinical management and outcomes in rectal cancer.
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Affiliation(s)
- P J Brown
- Department of Clinical Radiology, Lincoln Wing, St James' University Hospital, Leeds Teaching Hospitals NHS Trust, Beckett Street, Leeds, LS9 7TF, UK.
| | - H Rossington
- Epidemiology and Biostatistics, Section of Pathology and Data Analytics, Medical Research at St. James's, University of Leeds, St James's Institute of Oncology, St James's University Hospital, Leeds, LS9 7TF, UK
| | - J Taylor
- Epidemiology and Biostatistics, Section of Pathology and Data Analytics, Medical Research at St. James's, University of Leeds, St James's Institute of Oncology, St James's University Hospital, Leeds, LS9 7TF, UK
| | - D M J Lambregts
- Department of Radiology, Netherlands Cancer Institute - Antoni van Leeuwenhoek, PO Box 90203, 1006 BE Amsterdam, Netherlands
| | - E J A Morris
- Epidemiology and Biostatistics, Section of Pathology and Data Analytics, Medical Research at St. James's, University of Leeds, St James's Institute of Oncology, St James's University Hospital, Leeds, LS9 7TF, UK
| | - N P West
- Pathology, Section of Pathology and Data Analytics, Medical Research at St. James's, University of Leeds, St James's Institute of Oncology, St James's University Hospital, Leeds, LS9 7TF, UK
| | - P Quirke
- Pathology, Section of Pathology and Data Analytics, Medical Research at St. James's, University of Leeds, St James's Institute of Oncology, St James's University Hospital, Leeds, LS9 7TF, UK
| | - D Tolan
- Department of Clinical Radiology, Lincoln Wing, St James' University Hospital, Leeds Teaching Hospitals NHS Trust, Beckett Street, Leeds, LS9 7TF, UK
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Carvalho AL, Miquel-Clopés A, Wegmann U, Jones E, Stentz R, Telatin A, Walker NJ, Butcher WA, Brown PJ, Holmes S, Dennis MJ, Williamson ED, Funnell SGP, Stock M, Carding SR. Use of bioengineered human commensal gut bacteria-derived microvesicles for mucosal plague vaccine delivery and immunization. Clin Exp Immunol 2019; 196:287-304. [PMID: 30985006 PMCID: PMC6514708 DOI: 10.1111/cei.13301] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2019] [Indexed: 12/19/2022] Open
Abstract
Plague caused by the Gram‐negative bacterium, Yersinia pestis, is still endemic in parts of the world today. Protection against pneumonic plague is essential to prevent the development and spread of epidemics. Despite this, there are currently no licensed plague vaccines in the western world. Here we describe the means of delivering biologically active plague vaccine antigens directly to mucosal sites of plague infection using highly stable microvesicles (outer membrane vesicles; OMVs) that are naturally produced by the abundant and harmless human commensal gut bacterium Bacteroides thetaiotaomicron (Bt). Bt was engineered to express major plague protective antigens in its OMVs, specifically Fraction 1 (F1) in the outer membrane and LcrV (V antigen) in the lumen, for targeted delivery to the gastrointestinal (GI) and respiratory tracts in a non‐human primate (NHP) host. Our key findings were that Bt OMVs stably expresses F1 and V plague antigens, particularly the V antigen, in the correct, immunogenic form. When delivered intranasally V‐OMVs elicited substantive and specific immune and antibody responses, both in the serum [immunoglobulin (Ig)G] and in the upper and lower respiratory tract (IgA); this included the generation of serum antibodies able to kill plague bacteria. Our results also showed that Bt OMV‐based vaccines had many desirable characteristics, including: biosafety and an absence of any adverse effects, pathology or gross alteration of resident microbial communities (microbiotas); high stability and thermo‐tolerance; needle‐free delivery; intrinsic adjuvanticity; the ability to stimulate both humoral and cell‐mediated immune responses; and targeting of primary sites of plague infection.
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Affiliation(s)
- A L Carvalho
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, UK
| | - A Miquel-Clopés
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, UK
| | - U Wegmann
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, UK
| | - E Jones
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, UK
| | - R Stentz
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, UK
| | - A Telatin
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, UK
| | - N J Walker
- Defence Science and Technology Laboratory, Porton, Salisbury, UK
| | - W A Butcher
- Defence Science and Technology Laboratory, Porton, Salisbury, UK
| | - P J Brown
- Public Health England, Porton, Porton, Salisbury, UK
| | - S Holmes
- Public Health England, Porton, Porton, Salisbury, UK
| | - M J Dennis
- Public Health England, Porton, Porton, Salisbury, UK
| | - E D Williamson
- Defence Science and Technology Laboratory, Porton, Salisbury, UK
| | - S G P Funnell
- Public Health England, Porton, Porton, Salisbury, UK
| | - M Stock
- Plant Biotechnology Ltd, Norwich, UK
| | - S R Carding
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, UK.,Norwich Medical School, University East Anglia, Norwich, UK
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21
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Chatterji T, Stunault A, Brown PJ. Single crystal polarized neutron diffraction study of the magnetic structure of HoFeO 3. J Phys Condens Matter 2017; 29:385802. [PMID: 28677596 DOI: 10.1088/1361-648x/aa7db9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Polarised neutron diffraction measurements have been made on HoFeO3 single crystals magnetised in both the [0 0 1] and [1 0 0] directions (Pbnm setting). The polarisation dependencies of Bragg reflection intensities were measured both with a high field of [Formula: see text] T parallel to [0 0 1] at [Formula: see text] K and with the lower field [Formula: see text] T parallel to [1 0 0] at [Formula: see text] K. A Fourier projection of magnetization induced parallel to [0 0 1], made using the hk0 reflections measured in 9 T, indicates that almost all of it is due to alignment of Ho moments. Further analysis of the asymmetries of general reflections in these data showed that although, at 70 K, 9 T applied parallel to [0 0 1] hardly perturbs the antiferromagnetic order of the Fe sublattices, it induces significant antiferromagnetic order of the Ho sublattices in the [Formula: see text] plane, with the antiferromagnetic components of moment having the same order of magnitude as the induced ferromagnetic ones. Strong intensity asymmetries measured in the low temperature [Formula: see text] structure with a lower field, 0.5 T [Formula: see text] [1 0 0] allowed the variation of the ordered components of the Ho and Fe moments to be followed. Their absolute orientations, in the [Formula: see text] domain stabilised by the field were determined relative to the distorted perovskite structure. This relationship fixes the sign of the Dzyalshinski-Moriya (D-M) interaction which leads to the weak ferromagnetism. Our results indicate that the combination of strong y-axis anisotropy of the Ho moments and Ho-Fe exchange interactions breaks the centrosymmetry of the structure and could lead to ferroelectric polarization.
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22
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Kaniskan HÜ, Eram MS, Liu J, Smil D, Martini ML, Shen Y, Santhakumar V, Brown PJ, Arrowsmith C, Vedadi M, Jin J. Design and synthesis of selective, small molecule inhibitors of coactivator-associated arginine methyltransferase 1 (CARM1). Medchemcomm 2016; 7:1793-1796. [PMID: 28042453 DOI: 10.1039/c6md00342g] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Coactivator-associated arginine methyltransferase 1 (CARM1) is a type I protein arginine methyltransferase (PRMT) that catalyzes the conversion of arginine into monomethylarginine (MMA) and further into asymmetric dimethylarginine (ADMA). CARM1 methylates histone 3 arginines 17 and 26, as well as numerous non-histone proteins including CBP/p300, SRC-3, NCOA2, PABP1, and SAP49, while also functioning as a coactivator for various proteins that have been linked to cancer such as p53, NF-κβ, β-catenin, E2F1 and steroid hormone receptor ERα. As a result, CARM1 is involved in transcriptional activation, cellular differentiation, cell cycle progression, RNA splicing and DNA damage response. It has been associated with several human cancers including breast, colon, prostate and lung cancers and thus, is a potential oncological target. Herein, we present the design and synthesis of a series of CARM1 inhibitors. Based on a fragment hit, we discovered compound 9 as a potent inhibitor that displayed selectivity for CARM1 over other PRMTs.
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Affiliation(s)
- H Ü Kaniskan
- Departments of Pharmacological Sciences and Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - M S Eram
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - J Liu
- Departments of Pharmacological Sciences and Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - D Smil
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - M L Martini
- Departments of Pharmacological Sciences and Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Y Shen
- Departments of Pharmacological Sciences and Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - V Santhakumar
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - P J Brown
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada
| | - C Arrowsmith
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada; Princess Margaret Cancer Centre and Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 2M9, Canada
| | - M Vedadi
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada; Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - J Jin
- Departments of Pharmacological Sciences and Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
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Brown PJ, Bradshaw JM, Sozmen M, Campbell RH. Feline necrotising sialometaplasia: A report of two cases. J Feline Med Surg 2016; 6:279-81. [PMID: 15265483 DOI: 10.1016/j.jfms.2003.11.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 10/27/2003] [Accepted: 11/12/2003] [Indexed: 10/26/2022]
Abstract
Unilateral swelling of submandibular salivary gland in two cats was diagnosed as necrotising sialometaplasia. Histological features that differentiate the disease from other salivary gland lesions, particularly neoplasia are: lobular necrosis of salivary tissue; squamous metaplasia conforming to duct and/or acinar outlines; preservation of salivary lobular morphology; and variable inflammation and granulation tissue.
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Affiliation(s)
- P J Brown
- Comparative Pathology Laboratory, Division of Veterinary Pathology, Infection and Immunity, Department of Clinical Veterinary Science, University of Bristol Veterinary School, Langford House, Langford, Bristol BS40 5DU, UK.
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Brown PJ, Wong KK, Felce SL, Lyne L, Spearman H, Soilleux EJ, Pedersen LM, Møller MB, Green TM, Gascoyne DM, Banham AH. FOXP1 suppresses immune response signatures and MHC class II expression in activated B-cell-like diffuse large B-cell lymphomas. Leukemia 2015; 30:605-16. [PMID: 26500140 PMCID: PMC4777777 DOI: 10.1038/leu.2015.299] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 10/07/2015] [Accepted: 10/13/2015] [Indexed: 12/25/2022]
Abstract
The FOXP1 (forkhead box P1) transcription factor is a marker of poor prognosis in diffuse large B-cell lymphoma (DLBCL). Here microarray analysis of FOXP1-silenced DLBCL cell lines identified differential regulation of immune response signatures and major histocompatibility complex class II (MHC II) genes as some of the most significant differences between germinal center B-cell (GCB)-like DLBCL with full-length FOXP1 protein expression versus activated B-cell (ABC)-like DLBCL expressing predominantly short FOXP1 isoforms. In an independent primary DLBCL microarray data set, multiple MHC II genes, including human leukocyte antigen DR alpha chain (HLA-DRA), were inversely correlated with FOXP1 transcript expression (P<0.05). FOXP1 knockdown in ABC-DLBCL cells led to increased cell-surface expression of HLA-DRA and CD74. In R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone)-treated DLBCL patients (n=150), reduced HLA-DRA (<90% frequency) expression correlated with inferior overall survival (P=0.0003) and progression-free survival (P=0.0012) and with non-GCB subtype stratified by the Hans, Choi or Visco-Young algorithms (all P<0.01). In non-GCB DLBCL cases with <90% HLA-DRA, there was an inverse correlation with the frequency (P=0.0456) and intensity (P=0.0349) of FOXP1 expression. We propose that FOXP1 represents a novel regulator of genes targeted by the class II MHC transactivator CIITA (MHC II and CD74) and therapeutically targeting the FOXP1 pathway may improve antigen presentation and immune surveillance in high-risk DLBCL patients.
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Affiliation(s)
- P J Brown
- NDCLS, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - K K Wong
- Department of Immunology, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, Kelantan, Malaysia
| | - S L Felce
- NDCLS, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - L Lyne
- NDCLS, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - H Spearman
- NDCLS, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - E J Soilleux
- NDCLS, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - L M Pedersen
- Department of Haematology, Roskilde Hospital, Roskilde, Denmark
| | - M B Møller
- Department of Pathology, Odense University Hospital, Odense, Denmark
| | - T M Green
- Department of Pathology, Odense University Hospital, Odense, Denmark
| | - D M Gascoyne
- NDCLS, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - A H Banham
- NDCLS, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
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25
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Roberts KK, Cochet AE, Lamb PB, Brown PJ, Battafarano DF, Brunt EM, Harrison SA. The prevalence of NAFLD and NASH among patients with psoriasis in a tertiary care dermatology and rheumatology clinic. Aliment Pharmacol Ther 2015; 41:293-300. [PMID: 25521607 DOI: 10.1111/apt.13042] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 10/23/2014] [Accepted: 11/17/2014] [Indexed: 12/14/2022]
Abstract
BACKGROUND Psoriasis has been linked to metabolic syndrome and non-alcoholic fatty liver disease (NAFLD). Data suggest that the prevalence of NAFLD is increased in patients with psoriasis. The aim of this study was to determine the prevalence and severity of NAFLD in this patient population. AIM To determine the prevalence of both NAFLD and non-alcoholic steatohepatitis (NASH) in patients with psoriasis. METHODS Patients between the ages of 18 and 70 years with a diagnosis of psoriasis or psoriatic arthritis and followed by either the Dermatology or Rheumatology Division within the Department of Medicine at San Antonio Military Medical Center were considered for enrollment. Each patient completed a questionnaire, underwent a thorough skin evaluation, and had a right upper quadrant ultrasound and fasting blood work. If the liver enzymes were elevated or fatty liver detected on imaging, percutaneous liver biopsy was recommended. RESULTS One hundred and twenty-nine patients were enrolled and 103 completed all necessary studies. The participants were predominantly middle aged (52.7 ± 12) and overweight or obese (average BMI 30.1 ± 5.9, range: 19.8-52.5 kg/m(2)). 53% (n = 54) were male while 15% (n = 15) of participants identified themselves as being a diabetic. The overall prevalence of NAFLD was 47%. The overall prevalence of NASH was 22% in those who underwent biopsy. CONCLUSIONS Non-alcoholic fatty liver disease is very common among our cohort of patients with psoriasis, occurring in roughly 47% of patients. The more progressive form of the disease, NASH, is found in approximately one in five patients. Health care providers should be mindful of this association given the high prevalence of both NAFLD and NASH in this cohort of patients.
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Affiliation(s)
- K K Roberts
- Division of Gastroenterology and Hepatology, Department of Medicine, San Antonio Military Medical Center, Fort Sam Houston, TX, USA
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Higgins RH, Thurber CS, Assaranurak I, Brown PJ. Multiparental mapping of plant height and flowering time QTL in partially isogenic sorghum families. G3 (Bethesda) 2014; 4:1593-602. [PMID: 25237111 PMCID: PMC4169151 DOI: 10.1534/g3.114.013318] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Accepted: 06/11/2014] [Indexed: 12/31/2022]
Abstract
Sorghum varieties suitable for grain production at temperate latitudes show dwarfism and photoperiod insensitivity, both of which are controlled by a small number of loci with large effects. We studied the genetic control of plant height and flowering time in five sorghum families (A-E), each derived from a cross between a tropical line and a partially isogenic line carrying introgressions derived from a common, temperate-adapted donor. A total of 724 F2:3 lines were phenotyped in temperate and tropical environments for plant height and flowering time and scored at 9139 SNPs using genotyping-by-sequencing. Biparental mapping was compared with multiparental mapping in different subsets of families (AB, ABC, ABCD, and ABCDE) using both a GWAS approach, which fit each QTL as a single effect across all families, and using a joint linkage approach, which fit QTL effects as nested within families. GWAS using all families (ABCDE) performed best at the cloned Dw3 locus, whereas joint linkage using all families performed best at the cloned Ma1 locus. Both multiparental approaches yielded apparently synthetic associations due to genetic heterogeneity and were highly dependent on the subset of families used. Comparison of all mapping approaches suggests that a GA2-oxidase underlies Dw1, and that a mir172a gene underlies a Dw1-linked flowering time QTL.
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Affiliation(s)
- R H Higgins
- Department of Crop Sciences, University of Illinois, Urbana, Illinois 61801 Energy Biosciences Institute, University of Illinois, Urbana, Illinois 61801
| | - C S Thurber
- Energy Biosciences Institute, University of Illinois, Urbana, Illinois 61801
| | - I Assaranurak
- Department of Crop Sciences, University of Illinois, Urbana, Illinois 61801
| | - P J Brown
- Department of Crop Sciences, University of Illinois, Urbana, Illinois 61801 Energy Biosciences Institute, University of Illinois, Urbana, Illinois 61801
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Brown PJ, Marquard JL, Amster B, Romoser M, Friderici J, Goff S, Fisher D. What do physicians read (and ignore) in electronic progress notes? Appl Clin Inform 2014; 5:430-44. [PMID: 25024759 DOI: 10.4338/aci-2014-01-ra-0003] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Accepted: 03/30/2014] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE Several studies have documented the preference for physicians to attend to the impression and plan section of a clinical document. However, it is not clear how much attention other sections of a document receive. The goal of this study was to identify how physicians distribute their visual attention while reading electronic notes. METHODS We used an eye-tracking device to assess the visual attention patterns of ten hospitalists as they read three electronic notes. The assessment included time spent reading specific sections of a note as well as rates of reading. This visual analysis was compared with the content of simulated verbal handoffs for each note and debriefing interviews. RESULTS Study participants spent the most time in the "Impression and Plan" section of electronic notes and read this section very slowly. Sections such as the "Medication Profile", "Vital Signs" and "Laboratory Results" received less attention and were read very quickly even if they contained more content than the impression and plan. Only 9% of the content of physicians' verbal handoff was found outside of the "Impression and Plan." CONCLUSION Physicians in this study directed very little attention to medication lists, vital signs or laboratory results compared with the impression and plan section of electronic notes. Optimizing the design of electronic notes may include rethinking the amount and format of imported patient data as this data appears to largely be ignored.
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Affiliation(s)
- P J Brown
- Division of Clinical Informatics, Baystate Health , Springfield, MA, USA
| | - J L Marquard
- College of Engineering, University of Massachusetts Amherst , Amherst, MA, USA
| | - B Amster
- College of Engineering, University of Massachusetts Amherst , Amherst, MA, USA
| | - M Romoser
- College of Engineering, University of Massachusetts Amherst , Amherst, MA, USA
| | - J Friderici
- Department of Epidemiology & Biostatistics, Baystate Health , Springfield, MA, USA
| | - S Goff
- Department of Epidemiology & Biostatistics, Baystate Health , Springfield, MA, USA
| | - D Fisher
- College of Engineering, University of Massachusetts Amherst , Amherst, MA, USA
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Wong KK, Gascoyne DM, Brown PJ, Soilleux EJ, Snell C, Chen H, Lyne L, Lawrie CH, Gascoyne RD, Pedersen LM, Møller MB, Pulford K, Murphy D, Green TM, Banham AH. Erratum: Reciprocal expression of the endocytic protein HIP1R and its repressor FOXP1 predicts outcome in R-CHOP-treated diffuse large B-cell lymphoma patients. Leukemia 2014. [DOI: 10.1038/leu.2013.276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
Human predispositions to fatness and obesity are best understood in the context of cultural and biological evolution. Both genes and cultural traits that were adaptive in the context of past food scarcities play a role today in the etiology of maladaptive adult obesity. The etiology of obesity must account for the social distribution of the condition with regard to gender, ethnicity, social class, and economic modernization. This distribution, which has changed throughout history, undoubtedly involves cultural factors. A model of culture is presented that has advantages over an undifferentiated concept of the "environment" for hypothesis generation. Cultural predispositions to obesity are found in the productive economy, the mode of reproduction, social structure, and cultural beliefs about food and ideal body size. Cross-cultural comparison can contribute to an understanding of the prevalence of obesity in some modern affluent societies.
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Affiliation(s)
- P J Brown
- Department of Anthropology, Emory University, 30322, Atlanta, GA
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Wong KK, Gascoyne DM, Brown PJ, Soilleux EJ, Snell C, Chen H, Lyne L, Lawrie CH, Gascoyne RD, Pedersen LM, Møller MB, Pulford K, Murphy D, Green TM, Banham AH. Reciprocal expression of the endocytic protein HIP1R and its repressor FOXP1 predicts outcome in R-CHOP-treated diffuse large B-cell lymphoma patients. Leukemia 2013; 28:362-72. [PMID: 23884370 DOI: 10.1038/leu.2013.224] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 07/18/2013] [Accepted: 07/19/2013] [Indexed: 02/07/2023]
Abstract
We previously identified autoantibodies to the endocytic-associated protein Huntingtin-interacting protein 1-related (HIP1R) in diffuse large B-cell lymphoma (DLBCL) patients. HIP1R regulates internalization of cell surface receptors via endocytosis, a process relevant to many therapeutic strategies including CD20 targeting with rituximab. In this study, we characterized HIP1R expression patterns, investigated a mechanism of transcriptional regulation and its clinical relevance in DLBCL patients treated with immunochemotherapy (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone, R-CHOP). HIP1R was preferentially expressed in germinal center B-cell-like DLBCL (P<0.0001) and inversely correlated with the activated B-cell-like DLBCL (ABC-DLBCL) associated transcription factor, Forkhead box P1 (FOXP1). HIP1R was confirmed as a direct FOXP1 target gene in ABC-DLBCL by FOXP1-targeted silencing and chromatin immunoprecipitation. Lower HIP1R protein expression (≤ 10% tumoral positivity) significantly correlated with inferior overall survival (OS, P=0.0003) and progression-free survival (PFS, P=0.0148) in R-CHOP-treated DLBCL patients (n=157). Reciprocal expression with ≥ 70% FOXP1 positivity defined FOXP1(hi)/HIP1R(lo) patients with particularly poor outcome (OS, P=0.0001; PFS, P=0.0016). In an independent R-CHOP-treated DLBCL (n=233) microarray data set, patients with transcript expression in lower quartile HIP1R and FOXP1(hi)/HIP1R(lo) subgroups exhibited worse OS, P=0.0044 and P=0.0004, respectively. HIP1R repression by FOXP1 is strongly associated with poor outcome, thus further understanding of FOXP1-HIP1R and/or endocytic signaling pathways might give rise to novel therapeutic options for DLBCL.
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Affiliation(s)
- K K Wong
- 1] NDCLS, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK [2] Department of Immunology, School of Medical Sciences, Universiti Sains Malaysia, Kelantan, Malaysia
| | - D M Gascoyne
- NDCLS, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - P J Brown
- NDCLS, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - E J Soilleux
- NDCLS, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - C Snell
- NDCLS, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - H Chen
- Centre for Human Proteomics, Royal College of Surgeons in Ireland, Dublin 2, Ireland
| | - L Lyne
- NDCLS, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - C H Lawrie
- 1] NDCLS, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK [2] Biodonostia Research Institute, San Sebastian, Spain [3] IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - R D Gascoyne
- Department of Pathology and Experimental Therapeutics, Centre for Lymphoid Cancer, BC Cancer Agency and BC Cancer Research Centre, Vancouver, Canada
| | - L M Pedersen
- Department of Haematology, Roskilde Hospital, Roskilde, Denmark
| | - M B Møller
- Department of Pathology, Odense University Hospital, Odense, Denmark
| | - K Pulford
- NDCLS, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - D Murphy
- 1] Centre for Human Proteomics, Royal College of Surgeons in Ireland, Dublin 2, Ireland [2] School of Biological Sciences, Dublin Institute of Technology, Dublin 8, Ireland
| | - T M Green
- Department of Pathology, Odense University Hospital, Odense, Denmark
| | - A H Banham
- NDCLS, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
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Brown PJ, Chatterji T. Polarization dependence of magnetic Bragg scattering in YMn2O5. J Phys Condens Matter 2013; 25:236004. [PMID: 23685626 DOI: 10.1088/0953-8984/25/23/236004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The polarization dependence of the intensity of elastic magnetic scattering from YMn2O5 single crystals has been measured at 25 K in magnetic fields between 1 and 9 T. A significant polarization dependence was observed in the intensities of magnetic satellite reflections, propagation vector τ = ½, 0, ¼, measured with both the [100] and [010] axes parallel to the common polarization and applied field direction. The intensity asymmetries A observed in sets of orthorhombic equivalent reflections show systematic relationships which allow the phase relationship between different components of their magnetic interaction vectors to be determined. They fix the orientation relationships between the small y and z moments on the Mn(4+) and Mn(3+) sub-lattices and have allowed a further refinement of the magnetic structure, which determines the phases of the vector Fourier components with much higher precision. Systematic differences found between values of A(hkl) and A(h¯k¯l¯) suggest that there is a small modulation of the nuclear structure which has the same wavevector as the magnetic modulation and gives rise to a small nuclear structure factor for the satellite reflections. The magnitudes of the differences suggest shifts in the atomic positions of the order of 0.05 Å.
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Affiliation(s)
- P J Brown
- Institut Laue Langevin, Grenoble, France.
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Brown PJ, Kainuma R, Kanomata T, Neumann KU, Okubo A, Umetsu RY, Ziebeck KRA. A polarized neutron study of the magnetization distribution in Co₂FeSi. J Phys Condens Matter 2013; 25:206002. [PMID: 23612471 DOI: 10.1088/0953-8984/25/20/206002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The magnetization distribution in Co2FeSi which has the largest moment per formula unit ∼6 μB of all Heusler alloys, has been determined using polarized neutron diffraction. The experimentally determined magnetization has been integrated over spheres centred on the three sites of the L12 structure giving μ Fe = 3.10(3) μB and μ Co = 1.43(2) μB, results which are slightly lower than the moments in atomic spheres of similar radii obtained in recent LDA + U band structure calculations (Li et al 2010 Chin. Phys. B 19 097102). Approximately 50% of the magnetic carriers at the Fe sites were found to be in orbitals with eg symmetry. This was higher, ≃65%, at the Co sites. Both Fe and Co were found to have orbital moments that are larger than those predicted. Comparison with similar results obtained for related alloys suggests that there must be a finite density of states in both spin bands at the Fermi energy indicating that Co2FeSi is not a perfect half-metallic ferromagnet.
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Affiliation(s)
- P J Brown
- Department of Physics, Loughborough University, LE11 3TU, UK
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Abstract
Epigenetic control of gene expression occurs at two distinctlevels: DNA methylation and histone modification. Over thepast 10 years, the discovery of epigenetic targets has acceleratedto the point where more than 400 domains have beenidentified that are involved in either DNA methylation, themodification of histones (and some nonhistones), or translationof these modifications into changes in gene expression
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Affiliation(s)
- S Müller
- Structural Genomics Consortium, University of Oxford, Oxford, UK
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Hearmon AJ, Fabrizi F, Chapon LC, Johnson RD, Prabhakaran D, Streltsov SV, Brown PJ, Radaelli PG. Electric field control of the magnetic chiralities in ferroaxial multiferroic RbFe(MoO4)2. Phys Rev Lett 2012; 108:237201. [PMID: 23003983 DOI: 10.1103/physrevlett.108.237201] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Indexed: 06/01/2023]
Abstract
The coupling of magnetic chiralities to the ferroelectric polarization in multiferroic RbFe(MoO4)2 is investigated by neutron spherical polarimetry. Because of the axiality of the crystal structure below T(c)=190 K, helicity and triangular chirality are symmetric-exchange coupled, explaining the onset of the ferroelectricity in this proper-screw magnetic structure--a mechanism that can be generalized to other systems with ferroaxial distortions in the crystal structure. With an applied electric field, we demonstrate control of the chiralities in both structural domains simultaneously.
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Affiliation(s)
- Alexander J Hearmon
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom.
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35
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Abstract
Congenital abnormalities of the reproductive tract of male sheep were surveyed at three abattoirs in the south west of England during the period June 2000-January 2004. A total of 7307 rams were examined [6521 lambs (prepubescent) and hoggets (aged from their first autumn after birth until first shorn) and 786 adult rams mature rams that had been exposed to ewes]. A total of 156 congenital lesions were detected, 87 of which occurred in lambs. Testicular hypoplasia was the most common lesion occurring in 69 lambs as well as eight hoggets ('microtestes' were recognized in nine other animals in which the testis was disproportionately smaller than the epididymis). The second most common lesion found was notched scrotum occurring in 34 animals (27 young rams and seven adults). Some cases of notched scrotum were accompanied by hypospadias which was seen in a total of seven lambs and eight hoggets. Other lesions, detected in five or less animals (less than approximately 0.05% of the animals examined), included cryptorchidism and various abnormalities of the epididymis (segmental aplasia of the epididymis, blind efferent ducts and epididymal cyst) and congenital scrotal hernia. The overall prevalence of congenital lesions of 2.21% emphasizes the importance of undertaking breeding soundness examinations of young rams before they are put with the flock.
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Affiliation(s)
- K C Smith
- School of Veterinary Science, University of Bristol, Bristol, UK
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Brown PJ, Gandy AP, Kainuma R, Kanomata T, Neumann KU, Oikawa K, Ouladdiaf B, Sheikh A, Ziebeck KRA. The field and temperature dependence of the magnetic and structural properties of the shape memory compound Ni(1.84)Mn(1.64)In(0.52). J Phys Condens Matter 2011; 23:456004. [PMID: 22037587 DOI: 10.1088/0953-8984/23/45/456004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Magnetization and high resolution neutron powder diffraction measurements have been made on the magnetic shape memory alloy Ni(1.84)Mn(1.64)In(0.52). The compound undergoes a broad structural phase transition, which on heating starts at ∼150 K and finishes at ∼215 K. On cooling there is a ∼20 K hysteresis. The high temperature parent phase is cubic (a = 5.988 Å) with the L2(1) structure in which the excess Mn atoms occupy the vacancies on the Ni and In sites. The magnetic moment is located mainly on the Mn atoms with the same magnitude on both the 4a (Mn) and 4b (In) sites. The low temperature martensite is monoclinic with parameters a = 4.405(2), b = 5.553(2), c = 12.950(2) Å, β = 86.47(10)° and space group P2/m. The magnetic properties of the martensitic phase are complex and indicate metamagnetic behaviour.
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Affiliation(s)
- P J Brown
- Department of Physics, Loughborough University, LE11 3TU, UK. Institut Laue Langevin, BP 156, 38042 Grenoble, France
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Gukasov A, Brown PJ. Determination of atomic site susceptibility tensors from neutron diffraction data on polycrystalline samples. J Phys Condens Matter 2010; 22:502201. [PMID: 21406791 DOI: 10.1088/0953-8984/22/50/502201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Polarized neutron diffraction can provide information about the atomic site susceptibility tensor χ(ij) characterizing the magnetic response of individual atoms to an external magnetic field (Gukasov and Brown 2002 J. Phys.: Condens. Mater. 14 8831). The six independent atomic susceptibility parameters (ASPs) can be determined from polarized neutron flipping ratio measurements on single crystals and visualized as magnetic ellipsoids which are analogous to the thermal ellipsoids obtained from atomic displacement parameters (ADPs). We demonstrate now that the information about local magnetic susceptibility at different magnetic sites in a crystal can also be obtained from polarized and unpolarized neutron diffraction measurements on magnetized powder samples. The validity of the method is illustrated by the results of such measurements on a polycrystalline sample of Tb(2)Sn(2)O(7).
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Affiliation(s)
- A Gukasov
- Laboratoire Léon Brillouin, CEA-CNRS, CE Saclay, Gif sur Yvette, France
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Brown PJ, Kanomata T, Neumann K, Neumann KU, Ouladdiaf B, Sheikh A, Ziebeck KRA. Atomic and magnetic order in the shape memory alloy Mn2NiGa. J Phys Condens Matter 2010; 22:506001. [PMID: 21406811 DOI: 10.1088/0953-8984/22/50/506001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Magnetization and high resolution neutron powder diffraction measurements on the magnetic shape memory alloy Mn(2)NiGa have confirmed that it is ferromagnetic with a Curie temperature above 500 K. The compound undergoes a broad structural phase transformation ΔT ∼ 90 K with a mean transition temperature T(M) ∼ 270 K. The high temperature parent phase is cubic (a = 5.937 Å) and has a modified L 2(1) structure. At 500 K the ordered magnetic moment essentially all on the 4a site is 1.35 μ(B)/Mn. The low temperature martensite has space group I4/mmm and is related to the cubic phase through a Bain transformation a(tet) = (a(cub) + b(cub))/2, b(tet) = (a(cub) - b(cub)) and c(tet) = c(cub) in which the change in cell volume is < 2.6%. In this structure at 5 K the ordered moment of ≈2.3 μ(B) is again found to be confined to the sites with full Mn occupation and is aligned parallel to c. Neutron diffraction patterns obtained at 5 K suggested the presence of a weak incommensurate antiferromagnetic phase characterized by either a ((1/3)0(1/3)) or (00(1/3)) propagation vector.
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Affiliation(s)
- P J Brown
- Department of Physics, Loughborough University, UK
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Brown PJ, Gandy AP, Kainuma R, Kanomata T, Miyamoto T, Nagasako M, Neumann KU, Sheikh A, Ziebeck KRA. Atomic order and magnetization distribution in the half metallic and nearly half metallic C1(b) compounds NiMnSb and PdMnSb. J Phys Condens Matter 2010; 22:206004. [PMID: 21393715 DOI: 10.1088/0953-8984/22/20/206004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Polarized neutron diffraction has been used to study the magnetization distribution in two isostructural inter-metallic compounds NiMnSb and PdMnSb. Band structure calculations have predicted that whereas the former should be a half metallic ferromagnet the latter should not. Measurements made at 5 K on different crystals show that disorder can occur between the A (Mn) and B (Sb) sites in both alloys and in the case of NiMnSb, by partial occupation of the void D sites by Ni. In all the crystals most of the moment was found on the Mn atoms in the A sites; in NiMnSb it is due to spin only but in PdMnSb there is evidence for a significant orbital contribution (g = 2.22). The magnitudes of the moments associated with each atom are in fair agreement with the theoretical values; however, the distribution of magnetization around the Mn atoms is found to have nearly spherical symmetry (40% e(g)) rather than the 50% e(g) character expected from the band structure.
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Affiliation(s)
- P J Brown
- Department of Physics, Loughborough University, LE11 3TU, UK. Institut Laue Langevin, BP 156, 38042 Grenoble, France
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Brown PJ, Gandy AP, Ishida K, Ito W, Kainuma R, Kanomata T, Neumann KU, Oikawa K, Ouladdiaf B, Sheikh A, Ziebeck KRA. Magnetic and structural properties of the magnetic shape memory compound Ni(2)Mn(1.48)Sb(0.52). J Phys Condens Matter 2010; 22:096002. [PMID: 21389429 DOI: 10.1088/0953-8984/22/9/096002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Magnetization and high resolution neutron powder diffraction measurements on the magnetic shape memory compound Ni(2)Mn(1.48)Sb(0.52) have confirmed that it is ferromagnetic below 350 K and undergoes a structural phase transition at T(M)≈310 K. The high temperature phase has the cubic L2(1) structure with a = 5.958 Å, with the excess manganese atoms occupying the 4(b) Sb sites. In the cubic phase above ≈310 K the manganese moments are ferromagnetically aligned. The magnetic moment at the 4(a) site is 1.57(12) μ(B) and it is almost zero (0.15(9) μ(B)) at the 4(b) site. The low temperature orthorhombic phase which is only fully established below 50 K has the space group Pmma with a cell related to the cubic one by a Bain transformation a(orth) = (a(cub) + b(cub))/2; b(orth) = c(cub) and c(orth) = (a(cub) - b(cub)). The change in cell volume is ≈2.5%. The spontaneous magnetization of samples cooled in fields less than 0.5 T decreases at temperatures below T(M) and at 2 K the magnetic moment per formula unit in fields up to 5.5 T is 2.01(5) μ(B). Neutron diffraction patterns obtained below ≈132 K gave evidence for a weak incommensurate magnetic modulation with propagation vector (2/3, 1/3, 0).
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Affiliation(s)
- P J Brown
- Department of Physics, Loughborough University, Leicestershire LE11 3TU, UK
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Pregelj M, Zaharko O, Zorko A, Kutnjak Z, Jeglic P, Brown PJ, Jagodic M, Jaglicić Z, Berger H, Arcon D. Spin amplitude modulation driven magnetoelectric coupling in the new multiferroic FeTe2O5Br. Phys Rev Lett 2009; 103:147202. [PMID: 19905598 DOI: 10.1103/physrevlett.103.147202] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Indexed: 05/28/2023]
Abstract
The magnetic and ferroelectric properties of the layered geometrically frustrated cluster compound FeTe2O5Br were investigated with single-crystal neutron diffraction and dielectric measurements. An incommensurate transverse amplitude modulated magnetic order with the wave vector q=(1/2,0.463,0) develops below T(N)=10.6(2) K. Simultaneously, a ferroelectric order due to exchange striction involving polarizable Te4+ lone-pair electrons develops perpendicular to q and to Fe3+ magnetic moments. The observed magnetoelectric coupling is proposed to originate from the temperature dependent phase difference between neighboring amplitude modulation waves.
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Affiliation(s)
- M Pregelj
- Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia
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Rayoo M, Yan M, Takano EA, Bates GJ, Brown PJ, Banham AH, Fox SB. Expression of the forkhead box transcription factor FOXP1 is associated with oestrogen receptor alpha, oestrogen receptor beta and improved survival in familial breast cancers. J Clin Pathol 2009; 62:896-902. [DOI: 10.1136/jcp.2009.065169] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Background:The role of FOXP1 in sporadic breast cancers has been widely studied but its role in familial breast cancers is yet unexplored.Aims:To investigate FOXP1 expression in different molecular subtypes of familial breast cancers and to correlate its expression with clinicopathological parameters, oestrogen receptors (ER) and survival.Methods:Immunohistochemical staining for FOXP1 was performed in 126 familial breast carcinomas comprising 35 BRCA1, 34 BRCA2 and 57 BRCAX.Results:Nuclear FOXP1 expression ranged from focal weak to widespread strong expression. Expression of FOXP1 was higher in familial breast cancers (54%) compared with sporadic cancers (46%) (p<0.001). There was a significant correlation between FOXP1 with ERα (p = 0.038) and ERβ (p = 0.007) in familial breast cancers. FOXP1 was more highly expressed in familial breast cancers compared with sporadic cancers for luminal (p = 0.021) and basal (p<0.001), but not HER2 and null phenotypes (both p>0.05). The absence of FOXP1 expression was associated with a shorter relapse-free (p = 0.025) and overall survival (p = 0.009) in familial breast cancer. Negativity for FOXP1 was associated with a significantly worse overall survival in BRCA2 cancers (p = 0.021) and there was a non-significant separation of the survival curves for BRCA1 cancers (p = 0.183). No differences in survival were seen for BRCAX cancers (p = 0.762).Conclusion:Results suggest that FOXP1 demonstrates different expression patterns in familial breast cancers than sporadic tumours, even in tumours showing similar phenotypes. They also suggest a different role of FOXP1 as a tumour suppressor in familial tumours, which is unrelated to ER expression and may impact on therapeutic options.
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Schmid J, Ling LJ, Leung JLS, Zhang N, Kolbe J, Wesley AW, Mills GD, Brown PJ, Jones DT, Laing RTR, Pattemore PK, Taylor DR, Grimwood K. Pseudomonas aeruginosa transmission is infrequent in New Zealand cystic fibrosis clinics. Eur Respir J 2008; 32:1583-90. [PMID: 18715877 DOI: 10.1183/09031936.00099508] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Pseudomonas aeruginosa is an important pathogen in cystic fibrosis (CF). Although most patients harbour unique P. aeruginosa isolates, some clinics report patients sharing common strains. The overall importance of person-to-person transmission in P. aeruginosa acquisition and whether routine patient segregation is necessary remains uncertain. The present authors therefore investigated the extent of P. aeruginosa transmission in New Zealand CF clinics. New Zealand's seven major CF centres were assessed, combining epidemiological data with computer-assisted SalI DNA fingerprinting of 496 isolates from 102 patients. One cluster of related isolates was significantly more prevalent in the largest clinic than expected by chance. The seven patients with isolates belonging to this cluster had more contact with each other than the remaining patients attending this centre. No other convincing evidence of transmission was found in any of the other smaller clinics. Three P. aeruginosa strains believed to be transmissible between patients in Australian and British CF clinics are present in New Zealand, but there was no definite evidence they had spread. Pseudomonas aeruginosa transmission is currently infrequent in New Zealand cystic fibrosis clinics. This situation could change rapidly and ongoing surveillance is required. The current results confirm that computer-assisted SalI DNA fingerprinting is ideally suited for such surveillance.
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Affiliation(s)
- J Schmid
- Institute of Molecular Biosciences, Massey University, Auckland, New Zealand
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Radaelli PG, Chapon LC, Daoud-Aladine A, Vecchini C, Brown PJ, Chatterji T, Park S, Cheong SW. Electric field switching of antiferromagnetic domains in YMn2O5: a probe of the multiferroic mechanism. Phys Rev Lett 2008; 101:067205. [PMID: 18764498 DOI: 10.1103/physrevlett.101.067205] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Indexed: 05/26/2023]
Abstract
We employ neutron spherical polarimetry to determine the nature and population of the coexisting antiferromagnetic domains in multiferroic YMn2O5. By applying an electric field, we prove that reversing the electrical polarization results in the population inversion of two types of in-plane domains, related to each other by inversion. Our results are completely consistent with the exchange-striction mechanism of ferroelectricity, and support a unified model where cycloidal ordering is induced by coupling to the main magnetic order parameter.
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Affiliation(s)
- P G Radaelli
- ISIS facility, Rutherford Appleton Laboratory-STFC, Chilton, Didcot, Oxfordshire, OX11 0QX, United Kingdom
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Brown PJ, Kagaya R, Banham AH. Characterization of human FOXP1 isoform 2, using monoclonal antibody 4E3-G11, and intron retention as a tissue-specific mechanism generating a novel FOXP1 isoform. Histopathology 2008; 52:632-7. [DOI: 10.1111/j.1365-2559.2008.02990.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Lawrie CH, Saunders NJ, Soneji S, Palazzo S, Dunlop HM, Cooper CDO, Brown PJ, Troussard X, Mossafa H, Enver T, Pezzella F, Boultwood J, Wainscoat JS, Hatton CSR. MicroRNA expression in lymphocyte development and malignancy. Leukemia 2008; 22:1440-6. [DOI: 10.1038/sj.leu.2405083] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Abstract
The incidence of cryptorchidism in ram lambs of the North Ronaldsay breed was recorded between 1998 and 2005. The overall incidence of cryptorchidism was 7.4 per cent (ranging from 2.4 per cent to 18.2 per cent in different years). In 87.3 per cent of the cases only one testis was retained, with the right testis being affected in 78.5 per cent of all the cryptorchids.
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Affiliation(s)
- K C Smith
- School of Clinical Veterinary Science, University of Bristol, Langford House, Langford, Bristol
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Schonbrunn A, Gu YZ, Brown PJ, Loose-Mitchell D. Function and regulation of somatostatin receptor subtypes. Ciba Found Symp 2007; 190:204-17; discussion 217-21. [PMID: 7587648 DOI: 10.1002/9780470514733.ch13] [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] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The five known somatostatin receptors serve unique biological roles by virtue of their tissue-specific expression and particular biochemical properties. However, the function of any individual receptor in its normal physiological milieu is not understood. Studies to address this problem have been difficult because tissues and cell lines often express multiple somatostatin receptors and, in the absence of receptor-selective somatostatin analogues, the actions of individual receptors cannot be identified. Moreover, the biological and biochemical actions of somatostatin receptors depend on their cellular environment, so that the behaviour of a receptor expressed in heterologous cells does not necessarily mimic that of endogenous receptors. We have developed two approaches to examine somatostatin receptors which circumvent these problems. Using a biotinylated somatostatin analogue for affinity purification, we isolated somatostatin receptors together with associated G proteins. Subsequent analysis of the purified complex with G protein-specific antibodies showed that the somatostatin receptors in AR42J cells preferentially couple with two pertussis toxin-sensitive G proteins: Gi alpha 1 and Gi alpha 3. To examine individual receptor types, we developed receptor-specific antibodies and used them to show that both sstr1 and sstr2 proteins were present in the GH4C1 pituitary cell line whereas AR42J cells contained sstr2 but not sstr1. Immunoprecipitation of receptor-G protein complexes with GH4C1 cells showed that sstr1 and sstr2 are both coupled to pertussis toxin-sensitive G proteins, in contrast to the results observed when these receptors are overexpressed in some non-endocrine cells. We also showed that the somatostatin receptors in GH4C1 cells are subject to both homologous and heterologous hormonal regulation. The mechanisms involved in the regulation of different receptor types are now being characterized using the receptor-specific antibodies to isolate the individual receptor proteins. Elucidating signal transduction by endogenous somatostatin receptors as well as their hormonal regulation will be critical for understanding the functions of these receptors in the different physiological targets of somatostatin.
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Affiliation(s)
- A Schonbrunn
- Department of Pharmacology, University of Texas Medical School in Houston 77225, USA
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Abstract
An anthropological perspective on obesity considers both its evolutionary background and cross-cultural variation. It must explain three basic facts about obesity: gender dimorphism (women greater than men), an increase with modernization, and a positive association with socioeconomic status. Preindustrial diets varied in quality but shared a tendency to periodic shortages. Such shortages, particularly disadvantageous to women in their reproductive years, favored individuals who, for biological and cultural reasons, stored fat. Not surprisingly, the majority of the world's cultures had or have ideals of feminine beauty that include plumpness. This is consistent with the hypothesis that fat stores functioned as a cushion against food shortages during pregnancy and lactation. As obesity has increased, the traditional gap between males and females in its prevalence has narrowed. Under Western conditions of abundance, our biological tendency to regulate body weight at levels above our ideal cannot be easily controlled even with a complete reversal of the widespread cultural ideal of plumpness.
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