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Sharma A, Bhardwaj U, Marinova M, Da Costa A, Ferri A, Royer S, Kushwaha HS, Dhainaut J. Borophene: a piezocatalyst for water remediation. Chem Commun (Camb) 2024. [PMID: 38713495 DOI: 10.1039/d4cc00463a] [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: 05/08/2024]
Abstract
Borophene is an emerging two-dimensional material exhibiting exceptional piezocatalytic activity under the influence of ultrasonic vibrations, as exemplified herein by the decomposition of highly stable organic dyes in water. After 6 minutes of exposure, borophene sheets converted up to 92 percent of a mixture of dye molecules at room temperature.
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Affiliation(s)
- Aditi Sharma
- Materials Research Centre, Malaviya National Institute of Technology Jaipur (MNITJ), India
- Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, Lille F-59000, France.
| | - Upasana Bhardwaj
- Materials Research Centre, Malaviya National Institute of Technology Jaipur (MNITJ), India
| | - Maya Marinova
- Université de Lille, CNRS, INRA, Centrale Lille, Université Artois, FR 2638 - IMEC - Institut Michel-Eugène Chevreul, Lille 59000, France
| | - Antonio Da Costa
- Univ. Artois, CNRS, Centrale Lille, Univ. Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS), Lens F-62300, France
| | - Anthony Ferri
- Univ. Artois, CNRS, Centrale Lille, Univ. Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS), Lens F-62300, France
| | - Sébastien Royer
- Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, Lille F-59000, France.
| | - Himmat Singh Kushwaha
- Materials Research Centre, Malaviya National Institute of Technology Jaipur (MNITJ), India
- Shodh Lab, Suresh Gyan Vihar University Jaipur, 302017, India.
| | - Jérémy Dhainaut
- Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, Lille F-59000, France.
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Reilly S, Dhaliwal S, Arshad U, Macerollo A, Husain N, Costa AD. The effects of rivastigmine on neuropsychiatric symptoms in the early stages of Parkinson's disease: A systematic review. Eur J Neurol 2024; 31:e16142. [PMID: 37975761 DOI: 10.1111/ene.16142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 10/14/2023] [Accepted: 10/26/2023] [Indexed: 11/19/2023]
Abstract
BACKGROUND AND PURPOSE Neuropsychiatric symptoms including depression, apathy and psychosis occur frequently in patients with Parkinson's disease. A subgroup of patients develop cognitive impairment, which may increase the risk of falls due to reduced attention. The acetylcholinesterase inhibitor rivastigmine is beneficial in Parkinson's disease dementia, but whether the use of rivastigmine is effective earlier in the disease course is unclear. The aim of this systematic review was to assess the evidence for rivastigmine in the treatment of neuropsychiatric symptoms in Parkinson's disease without dementia. METHODS Embase, Medline, PsychINFO, Cochrane CENTRAL, NGLC, National Institute for Health and Care Excellence Evidence and medRxiv.org were searched for studies with terms relating to population (Parkinson's disease) and intervention (rivastigmine). Of 1922 references identified, 358 were duplications. Following title and abstract review, 1331 articles were excluded. After full-text review, nine articles remained. RESULTS Outcomes were heterogenous, therefore, the results are presented in narrative form. The articles included six randomized controlled trials, two open-label trials and one case series. Outcome measures included: time to develop psychosis; frequency of rapid eye movement sleep behaviour disorder (RBD) episodes; apathy; gait variability; falls; cognitive ability; Neuropsychiatric Inventory score; and regional spontaneous brain activity. CONCLUSIONS There is evidence that rivastigmine is beneficial for RBD and apathy in Parkinson's disease patients without dementia. There is high level evidence that rivastigmine reduces falls, which may be due to improved attention. The impact of rivastigmine on psychotic symptoms is less clear, but is supported by current theoretical models which involve acetylcholine dysfunction in the generation of visual hallucinations in Parkinson's disease.
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Affiliation(s)
- Siobhan Reilly
- Greater Manchester Mental Health NHS Foundation Trust, Manchester, UK
| | | | - Usman Arshad
- Pakistan Institute of Living and Learning, Karachi, Pakistan
- The University of Manchester, Manchester, UK
| | - Antonella Macerollo
- The Walton Centre NHS Foundation Trust for Neurology and Neurosurgery, Liverpool, UK
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Nusrat Husain
- The University of Manchester, Manchester, UK
- Mersey Care NHS Foundation Trust, Liverpool, UK
| | - Antonio Da Costa
- Peninsula Health, Frankston South, Melbourne, Victoria, Australia
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Mohandas Moolayil S, Da Costa A, Tahon JF, Bouad V, Hamieh A, Ponchel F, Ladmiral V, Rémiens D, Lefebvre JM, Desfeux R, Barrau S, Ferri A. New Insight into Nanoscale Identification of the Polar Axis Direction in Organic Ferroelectric Films. ACS Appl Mater Interfaces 2023. [PMID: 37878996 DOI: 10.1021/acsami.3c08579] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2023]
Abstract
Ferroelectric poly(vinylidene fluoride-co-trifluoroethylene) [P(VDF-co-TrFE)] thin films have been deposited by spin-coating onto the Bi0.5Na0.5TiO3(BNT)/LNO/SiO2/Si heterostructure. The copolymer microstructure investigated by using grazing-incidence wide-angle X-ray diffraction (GIWAXD) and deduced from the (200)/(110) reflections demonstrates that the b-axis in the P(VDF-co-TrFE) orthorhombic unit cell is either in the plane or out of the plane, depending on the face-on or on the two types of edge-on (called I and II) lamellar structures locally identified by atomic force microscopy (AFM). For edge-on I lamellae regions, the electroactivity (dzzeff ∼ -50.3 pm/V) is found to be twice as high as that measured for both edge-on II or face-on crystalline domains, as probed by piezoresponse force microscopy (PFM). This result is directly correlated to the direction of the ferroelectric polarization vector in the P(VDF-co-TrFE) orthorhombic cell: larger nanoscale piezoactivity is related to the b-axis which lies along the normal to the substrate plane in the case of the edge-on I domains. Here, the ability to thoroughly gain access to the as-grown polar axis direction within the edge-on crystal lamellae of the ferroelectric organic layers is evidenced by combining the nanometric resolution of the PFM technique with a statistical approach based on its spectroscopic tool. By the gathering of information at the nanoscale, two orientations for the polar b-axis are identified in edge-on lamellar structures. These findings contribute to a better understanding of the structure-property relationships in P(VDF-co-TrFE) films, which is a key issue for the design of future advanced organic electronic devices.
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Affiliation(s)
- Sajmohan Mohandas Moolayil
- Univ. Artois, CNRS, Centrale Lille, Univ. Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS), F-62300 Lens, France
| | - Antonio Da Costa
- Univ. Artois, CNRS, Centrale Lille, Univ. Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS), F-62300 Lens, France
| | - Jean-François Tahon
- Univ. Lille, Sciences et Technologies, CNRS, Centrale Lille, INRA, UMR 8207, Unité Matériaux Et Transformations (UMET), F-59655 Villeneuve D'Ascq, France
| | - Vincent Bouad
- Univ. Lille, Sciences et Technologies, CNRS, Centrale Lille, INRA, UMR 8207, Unité Matériaux Et Transformations (UMET), F-59655 Villeneuve D'Ascq, France
- ICGM, Univ Montpellier, CNRS, ENSCM, 34296 Montpellier, France
| | - Arthur Hamieh
- Univ. Lille, Sciences et Technologies, CNRS, Centrale Lille, INRA, UMR 8207, Unité Matériaux Et Transformations (UMET), F-59655 Villeneuve D'Ascq, France
- Département Opto-Acousto-Electronique (IEMN-DOAE), Site de Valenciennes - UPHF, Univ. Polytechnique Hauts-de-France (UPHF), CNRS, UMR 8520, Institut d'Electronique, de Microélectronique et de Nanotechnologie, F-59300 Valenciennes, France
| | - Freddy Ponchel
- Département Opto-Acousto-Electronique (IEMN-DOAE), Site de Valenciennes - UPHF, Univ. Polytechnique Hauts-de-France (UPHF), CNRS, UMR 8520, Institut d'Electronique, de Microélectronique et de Nanotechnologie, F-59300 Valenciennes, France
| | | | - Denis Rémiens
- Département Opto-Acousto-Electronique (IEMN-DOAE), Site de Valenciennes - UPHF, Univ. Polytechnique Hauts-de-France (UPHF), CNRS, UMR 8520, Institut d'Electronique, de Microélectronique et de Nanotechnologie, F-59300 Valenciennes, France
| | - Jean-Marc Lefebvre
- Univ. Lille, Sciences et Technologies, CNRS, Centrale Lille, INRA, UMR 8207, Unité Matériaux Et Transformations (UMET), F-59655 Villeneuve D'Ascq, France
| | - Rachel Desfeux
- Univ. Artois, CNRS, Centrale Lille, Univ. Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS), F-62300 Lens, France
| | - Sophie Barrau
- Univ. Lille, Sciences et Technologies, CNRS, Centrale Lille, INRA, UMR 8207, Unité Matériaux Et Transformations (UMET), F-59655 Villeneuve D'Ascq, France
| | - Anthony Ferri
- Univ. Artois, CNRS, Centrale Lille, Univ. Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS), F-62300 Lens, France
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Zidani J, Hassine K, Zannen M, Zeinert A, Da Costa A, Ferri A, Belhadi J, Majdoub M, El Marssi M, Lahmar A. Synthesis, Structural, Optical, and Electrical Characterization of Biochitosan/Na 0.5Bi 0.5TiO 3 Composite Thin-Film Materials. Micromachines (Basel) 2023; 14:1841. [PMID: 37893278 PMCID: PMC10609301 DOI: 10.3390/mi14101841] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 09/25/2023] [Accepted: 09/26/2023] [Indexed: 10/29/2023]
Abstract
The purpose of this research work was to synthesis bioderived nanocomposite films by incorporating Na0.5Bi0.5TiO3 (NBTO) nanoparticles into a chitosan matrix. The NBTO nanoparticles were synthesized using a traditional solid-state technique. Then, through a solution-casting approach, flexible composite films were fabricated using chitosan polymer. The study presents a range of compelling findings. For structural and morphological insights, scanning electron microscopy (SEM) reveals a fascinating morphology where NBTO nanoparticles are uniformly dispersed and interlocked with other particles, forming interconnected grains with significant interspaces within the chitosan matrix. For the optical properties, the spectral response within the 300-800 nm range is primarily governed by light scattering attributed to NBTO particles with diameter sizes ranging from 100 to 400 nm, as well as the distinctive bandgap exhibited by the NBTO phase. The investigation of dielectric properties demonstrates that composite films exhibit markedly higher dielectric values in comparison to pure chitosan films. It is noteworthy that an increase in the NBTO content results in a corresponding increase in dielectric values, enhancing the versatility of these materials. Local piezoelectric measurements utilizing piezoresponse force microscopy confirm the expected piezoelectric and ferroelectric behavior of NBTO particles when dispersed within the chitosan matrix. This research introduces a novel class of biocompatible nanocomposite materials, combining impressive structural attributes, enhanced dielectric properties, and piezoelectric capabilities. The outcomes of this study hold substantial promise for advanced applications in opto- and piezoelectric technologies, marking a significant advancement in biologically sourced materials with multifunctional properties.
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Affiliation(s)
- Jacem Zidani
- Laboratoire de Physique de la Matière Condensée (LPMC), Université de Picardie Jules Verne, 33 rue Saint-Leu, 80039 Amiens, CEDEX 1, France; (J.Z.); (M.E.M.)
- Laboratory of Interfaces and Advanced Materials (LIMA), Faculty of Sciences of Monastir, University of Monastir, Bd. of the Environment, Monastir 5019, Tunisia; (K.H.); (M.Z.); (M.M.)
| | - Khaoula Hassine
- Laboratory of Interfaces and Advanced Materials (LIMA), Faculty of Sciences of Monastir, University of Monastir, Bd. of the Environment, Monastir 5019, Tunisia; (K.H.); (M.Z.); (M.M.)
| | - Moneim Zannen
- Laboratory of Interfaces and Advanced Materials (LIMA), Faculty of Sciences of Monastir, University of Monastir, Bd. of the Environment, Monastir 5019, Tunisia; (K.H.); (M.Z.); (M.M.)
| | - Andreas Zeinert
- Laboratoire de Physique de la Matière Condensée (LPMC), Université de Picardie Jules Verne, 33 rue Saint-Leu, 80039 Amiens, CEDEX 1, France; (J.Z.); (M.E.M.)
| | - Antonio Da Costa
- University of Artois, CNRS, UMR 8181—UCCS—Unité de Catalyse et Chimie du Solide, 62300 Lens, France; (A.D.C.); (A.F.)
| | - Anthony Ferri
- University of Artois, CNRS, UMR 8181—UCCS—Unité de Catalyse et Chimie du Solide, 62300 Lens, France; (A.D.C.); (A.F.)
| | - Jamal Belhadi
- Laboratoire de Physique de la Matière Condensée (LPMC), Université de Picardie Jules Verne, 33 rue Saint-Leu, 80039 Amiens, CEDEX 1, France; (J.Z.); (M.E.M.)
| | - Mustapha Majdoub
- Laboratory of Interfaces and Advanced Materials (LIMA), Faculty of Sciences of Monastir, University of Monastir, Bd. of the Environment, Monastir 5019, Tunisia; (K.H.); (M.Z.); (M.M.)
| | - Mimoun El Marssi
- Laboratoire de Physique de la Matière Condensée (LPMC), Université de Picardie Jules Verne, 33 rue Saint-Leu, 80039 Amiens, CEDEX 1, France; (J.Z.); (M.E.M.)
| | - Abdelilah Lahmar
- Laboratoire de Physique de la Matière Condensée (LPMC), Université de Picardie Jules Verne, 33 rue Saint-Leu, 80039 Amiens, CEDEX 1, France; (J.Z.); (M.E.M.)
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Hammersley B, Bonello M, Fahad S, Costa AD, Mullin J, Farah J, Alusi S. 107 Short term neuropsychiatric outcomes of STN – DBS using directional vs conven- tional ring mode stimulation. J Neurol Psychiatry 2022. [DOI: 10.1136/jnnp-2022-abn2.151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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
Achieving the best outcome from STN stimulation for the treatment of Parkinson’s disease depends on ideal electrode placement and optimum stimulation settings. Motor symptoms are known to respond well to stimulation of the dorsolateral nucleus of the subthalamus and avoidance of tissue activation of the surrounding structures that may give rise to unwanted side effects including slurred speech, gait problems and neuropsychiatric symptoms. The recent development of multidirectional stimulation systems has enabled electrical current steering to activate the desired tissue areas in order to achieve effective neuromodulation.In this audit of 16 patients who underwent STN-DBS, we looked at the short-term neuropsychiatric outcomes in patients in whom current steering was deployed to achieve the best motor control to those in whom control was achieved by conventional ring mode stimulation. The patients’ symptoms were assessed at baseline and at 12 months using validated scales for anxiety, depression, apathy, and impulsivity. There was no statistical difference in the neuro-psychiatric outcomes between the two groups. However, the number of patients in this study was small and larger studies for longer periods are required to evaluate the potential benefit of this new development in minimising the neuropsychiatric complications of this treatment.
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Healy S, Shepherd H, Mooney N, Da Costa A, Osman-Farah J, Macerollo A. The effect of deep brain stimulation on impulse control related disorders in Parkinson's disease - A 10-year retrospective study of 137 patients. J Neurol Sci 2022; 440:120339. [PMID: 35853293 DOI: 10.1016/j.jns.2022.120339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 06/14/2022] [Accepted: 07/06/2022] [Indexed: 11/17/2022]
Affiliation(s)
- Sarah Healy
- The Walton Centre NHS Foundation Trust for Neurology and Neurosurgery, Liverpool, UK
| | - Hilary Shepherd
- The Walton Centre NHS Foundation Trust for Neurology and Neurosurgery, Liverpool, UK; University of Liverpool Medical School, Liverpool, UK
| | - Nicole Mooney
- The Walton Centre NHS Foundation Trust for Neurology and Neurosurgery, Liverpool, UK
| | - Antonio Da Costa
- The Walton Centre NHS Foundation Trust for Neurology and Neurosurgery, Liverpool, UK
| | - Jibril Osman-Farah
- The Walton Centre NHS Foundation Trust for Neurology and Neurosurgery, Liverpool, UK
| | - Antonella Macerollo
- The Walton Centre NHS Foundation Trust for Neurology and Neurosurgery, Liverpool, UK; Institute of Systems, Molecular and Integrative Biology, University of Liverpool, UK.
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Medarev SL, Machin D, Da Costa A, Hernandez J, Auger L, Qasim M, Trupiano S, Clark R, Hendrickson D, Schaeffer M, Schaeffer H, Muller‐Delp J. Microvascular Function in Skeletal Muscle of Adiponectin Knockout Mice. FASEB J 2022. [DOI: 10.1096/fasebj.2022.36.s1.r5297] [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: 11/11/2022]
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Folgado E, Guerre M, Da Costa A, Ferri A, Addad A, Ladmiral V, Semsarilar M. “One-pot” aminolysis/thia-Michael addition preparation of well-defined amphiphilic PVDF-b-PEG-b-PVDF triblock copolymers: self-assembly behaviour in mixed solvents. Polym Chem 2020. [DOI: 10.1039/c9py00970a] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Novel amphiphilic PVDF-based triblock copolymer (PVDF50-b-PEG136-b-PVDF50) is synthesized using RAFT polymerization and a one-pot thia-Michael addition. Self-assembly of this ABA copolymer resulted in formation of original crystalline structures.
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Affiliation(s)
- Enrique Folgado
- Institut Charles Gerhardt Montpellier
- ICGM UMR5253
- Univ Montpellier
- CNRS
- ENSCM
| | - Marc Guerre
- Institut Charles Gerhardt Montpellier
- ICGM UMR5253
- Univ Montpellier
- CNRS
- ENSCM
| | | | - Anthony Ferri
- Université Artois
- CNRS
- Centrale Lille
- ENSCL
- Université Lille
| | - Ahmed Addad
- Université Lille
- Sciences et Technologies
- CNRS
- Unité Matériaux Et Transformations (UMET)
- F-59000 Lille
| | - Vincent Ladmiral
- Institut Charles Gerhardt Montpellier
- ICGM UMR5253
- Univ Montpellier
- CNRS
- ENSCM
| | - Mona Semsarilar
- Institut Européen des Membranes
- IEM
- UMR5635
- Univ Montpellier
- CNRS
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Malli S, Pomel S, Ayadi Y, Deloménie C, Da Costa A, Loiseau PM, Bouchemal K. Topically Applied Chitosan-Coated Poly(isobutylcyanoacrylate) Nanoparticles Are Active Against Cutaneous Leishmaniasis by Accelerating Lesion Healing and Reducing the Parasitic Load. ACS Appl Bio Mater 2019; 2:2573-2586. [DOI: 10.1021/acsabm.9b00263] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Sophia Malli
- Institut Galien Paris Sud, UMR CNRS 8612, Univ. Paris-Sud, Université Paris-Saclay, Faculté de Pharmacie, 5, rue J.B. Clément, 92296 Cedex Châtenay-Malabry, France
- BioCIS Biomolécules: Conception, Isolement, Synthèse, Chimiothérapie Antiparasitaire, UMR CNRS 8076, Univ. Paris-Sud, Université Paris-Saclay, Faculté de Pharmacie, 5, rue J.B. Clément, 92296 Cedex Châtenay-Malabry, France
| | - Sebastien Pomel
- BioCIS Biomolécules: Conception, Isolement, Synthèse, Chimiothérapie Antiparasitaire, UMR CNRS 8076, Univ. Paris-Sud, Université Paris-Saclay, Faculté de Pharmacie, 5, rue J.B. Clément, 92296 Cedex Châtenay-Malabry, France
| | - Yasmine Ayadi
- Institut Galien Paris Sud, UMR CNRS 8612, Univ. Paris-Sud, Université Paris-Saclay, Faculté de Pharmacie, 5, rue J.B. Clément, 92296 Cedex Châtenay-Malabry, France
- BioCIS Biomolécules: Conception, Isolement, Synthèse, Chimiothérapie Antiparasitaire, UMR CNRS 8076, Univ. Paris-Sud, Université Paris-Saclay, Faculté de Pharmacie, 5, rue J.B. Clément, 92296 Cedex Châtenay-Malabry, France
| | - Claudine Deloménie
- Faculté de Pharmacie, Institut Paris Saclay d’Innovation Thérapeutique, UMS Inserm CNRS UPSud, Université Paris-Saclay, 92296 Cedex Châtenay-Malabry, France
| | - Antonio Da Costa
- Université d’Artois, CNRS, Centrale Lille, ENSCL, Université Lille, UMR 8181, Unité de Catalyse et de Chimie du Solide (UCCS), Faculté Jean-Perrin, Rue Jean Souvras − SP 18, 62307 Lens, France
| | - Philippe M. Loiseau
- BioCIS Biomolécules: Conception, Isolement, Synthèse, Chimiothérapie Antiparasitaire, UMR CNRS 8076, Univ. Paris-Sud, Université Paris-Saclay, Faculté de Pharmacie, 5, rue J.B. Clément, 92296 Cedex Châtenay-Malabry, France
| | - Kawthar Bouchemal
- Institut Galien Paris Sud, Junior Member of the Institut Universitaire de France, UMR CNRS 8612, Univ. Paris-Sud, Université Paris-Saclay, Faculté de Pharmacie, 5, rue J.B. Clément, 92296 Cedex Châtenay-Malabry, France
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Ahmed Z, Malli S, Diaz-Salmeron R, Destruel PL, Da Costa A, Guigner JM, Porcher F, Baptiste B, Ponchel G, Bouchemal K. New insights on the structure of hexagonally faceted platelets from hydrophobically modified chitosan and α-cyclodextrin. Int J Pharm 2018; 548:23-33. [DOI: 10.1016/j.ijpharm.2018.06.035] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 06/07/2018] [Accepted: 06/12/2018] [Indexed: 12/26/2022]
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Barrau S, Ferri A, Da Costa A, Defebvin J, Leroy S, Desfeux R, Lefebvre JM. Nanoscale Investigations of α- and γ-Crystal Phases in PVDF-Based Nanocomposites. ACS Appl Mater Interfaces 2018; 10:13092-13099. [PMID: 29589902 DOI: 10.1021/acsami.8b02172] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The impact of carbon nanotube (CNT) incorporation into semicrystalline poly(vinylidene fluoride), PVDF, was investigated at both the macro and nanoscales. A special effort was devoted to probe the local morphology and the mechanical, ferroelectric, piezoelectric, and electrical conductivity response by means of atomic force microscopy. Incorporation of CNTs mainly induces the development of the polar γ-phase, and as a consequence, the coexistence of the γ-phase with the most stable nonpolar α-phase is observed. A maximum γ-phase content is reached at 0.7 wt % CNT loading. The spherulitic morphology of the PVDF α-phase is assessed, in conjunction with the lack of any ferroelectric response, while the presence of the polar γ-phase is confirmed, owing to clear piezoresponse signals. Local piezoelectric measurements on γ-phase domains yield a maximum effective coefficient | d33| ≈ 13 pm/V, thus underlining the potential for applications of such functional PVDF-based nanocomposites in advanced piezoelectric devices. An increase in macroscopic conductivity with CNT content is observed, with a percolation threshold achieved for a composition close to 0.7 wt %. Nanoscale investigation of the electrical conductivity confirms the presence of some infinite CNT cluster homogeneously distributed over the surface. The macroscopic viscoelastic behavior of the composite reflects the reinforcing effect of CNTs, while the nanomechanical characterization yields a local contact modulus of the γ-phase domains larger than that of its α-phase counterpart, in agreement with the fact that the CNTs act as γ-phase promoters and subsequently reinforce the γ-domains.
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Affiliation(s)
- Sophie Barrau
- Université Lille, Sciences et Technologies, CNRS, Unité Matériaux Et Transformations (UMET) , F-59000 Lille , France
| | - Anthony Ferri
- Université Artois, CNRS, Centrale Lille, ENSCL, Université Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS) , F-62300 Lens , France
| | - Antonio Da Costa
- Université Artois, CNRS, Centrale Lille, ENSCL, Université Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS) , F-62300 Lens , France
| | - Juliette Defebvin
- Université Lille, Sciences et Technologies, CNRS, Unité Matériaux Et Transformations (UMET) , F-59000 Lille , France
| | - Sébastien Leroy
- Université Artois, CNRS, Centrale Lille, ENSCL, Université Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS) , F-62300 Lens , France
| | - Rachel Desfeux
- Université Artois, CNRS, Centrale Lille, ENSCL, Université Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS) , F-62300 Lens , France
| | - Jean-Marc Lefebvre
- Université Lille, Sciences et Technologies, CNRS, Unité Matériaux Et Transformations (UMET) , F-59000 Lille , France
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Carlier T, Ferri A, Saitzek S, Huvé M, Bayart A, Da Costa A, Desfeux R, Tebano A. Microstructure and local electrical behavior in [(Nd 2Ti 2O 7) 4/(SrTiO 3) n ] 10 ( n = 4-8) superlattices. RSC Adv 2018; 8:11262-11271. [PMID: 35542786 PMCID: PMC9078952 DOI: 10.1039/c8ra00824h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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: 01/26/2018] [Accepted: 03/08/2018] [Indexed: 11/21/2022] Open
Abstract
Artificial [(Nd2Ti2O7)4/(SrTiO3)n]10 superlattices (n = 4 and 8) were successfully epitaxially grown on SrTiO3 substrates by pulsed laser deposition using the in situ high energy electron diffraction reflection diagnostic. The crystallographic relationships between Nd2Ti2O7 (NTO) and SrTiO3 (STO) (layers and substrate) were: [100]NTO//[001]STO, [010]NTO//[1̄10]STO, and (00l)NTO//(110)STO. Nanoscale current variation was detected on both superlattices, with the (NTO4/STO4)10 heterostructure showing a higher density. The (NTO4/STO4)10 sample did not show a piezoelectric response when measured by piezo-force microscopy (PFM), while ambiguous piezoactivity was observed on the (NTO4/STO8)10 superlattice. Scanning transmission electron microscopy energy dispersive spectroscopy analysis showed the diffusion of Nd3+ cations on Sr2+ sites in SrTiO3 structure into the multilayers, which was more pronounced when the value of n was lower. These particular nanoscale electrical behaviors, evidenced by electrical conducting channels and misleading PFM signals, were mainly attributed to the presence of oxygen vacancies in the SrTiO3 layers at higher concentrations near the interface and to the mixed valence state of the titanium (Ti3+/Ti4+). This work showed the strong influence of interface structure on nanoscale electrical phenomena in complex oxide superlattices. Artificial [(Nd2Ti2O7)4/(SrTiO3)n]10 superlattices were epitaxially grown. Local conductivity and misleading PFM signals were mainly attributed to the oxygen vacancies in the SrTiO3 layers and to the mixed valence state of the titanium.![]()
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Affiliation(s)
- Thomas Carlier
- Univ. Artois, CNRS, Centrale Lille, ENSCL, Univ. Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS), Faculté des Sciences Jean Perrin Rue Jean Souvraz SP18 F-62300 Lens France +33 321791771
| | - Anthony Ferri
- Univ. Artois, CNRS, Centrale Lille, ENSCL, Univ. Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS), Faculté des Sciences Jean Perrin Rue Jean Souvraz SP18 F-62300 Lens France +33 321791771
| | - Sébastien Saitzek
- Univ. Artois, CNRS, Centrale Lille, ENSCL, Univ. Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS), Faculté des Sciences Jean Perrin Rue Jean Souvraz SP18 F-62300 Lens France +33 321791771
| | - Marielle Huvé
- Univ. Artois, CNRS, Centrale Lille, ENSCL, Univ. Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS), Faculté des Sciences Jean Perrin Rue Jean Souvraz SP18 F-62300 Lens France +33 321791771
| | - Alexandre Bayart
- Univ. Artois, CNRS, Centrale Lille, ENSCL, Univ. Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS), Faculté des Sciences Jean Perrin Rue Jean Souvraz SP18 F-62300 Lens France +33 321791771
| | - Antonio Da Costa
- Univ. Artois, CNRS, Centrale Lille, ENSCL, Univ. Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS), Faculté des Sciences Jean Perrin Rue Jean Souvraz SP18 F-62300 Lens France +33 321791771
| | - Rachel Desfeux
- Univ. Artois, CNRS, Centrale Lille, ENSCL, Univ. Lille, UMR 8181, Unité de Catalyse et Chimie du Solide (UCCS), Faculté des Sciences Jean Perrin Rue Jean Souvraz SP18 F-62300 Lens France +33 321791771
| | - Antonello Tebano
- CNR-SPIN, Department of Civil Engineering and Computer Science Engineering, University of Rome Tor Vergata, Via del Politecnico 00133 Rome Italy
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Bleta R, Menuel S, Léger B, Da Costa A, Monflier E, Ponchel A. Evidence for the existence of crosslinked crystalline domains within cyclodextrin-based supramolecular hydrogels through sol–gel replication. RSC Adv 2014. [DOI: 10.1039/c3ra47765g] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Petit M, Hemine J, Daoudi A, Ismaili M, Buisine JM, Da Costa A. Effect of the network density on dynamics of the soft and the Goldstone modes in short-pitch ferroelectric liquid crystals stabilized by an anisotropic polymer network. Phys Rev E 2009; 79:031705. [PMID: 19391960 DOI: 10.1103/physreve.79.031705] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2007] [Revised: 06/27/2008] [Indexed: 11/07/2022]
Abstract
We report the influence of the polymer network density formed in short-pitch ferroelectric liquid crystal (FLC) on the soft and the Goldstone dielectric relaxation modes. The experimental results of the pure FLC and the FLC stabilized by a polymer network with various densities are presented and compared. These results reveal that in the SmC;{ *} phase, when the polymer concentration increases, the Goldstone dielectric strength gradually decreases and the relaxation frequency is shifted to higher values. In the SmA;{ *} phase, the results show that close to the SmC;{ *}-SmA;{ *} transition temperature, T_{c} , the soft relaxation mode is largely influenced by the polymer network: a sharp decrease in the dielectric strength and an increase in the relaxation frequency when the polymer density increases were observed. The soft mode is relatively weakly affected by the network for higher temperatures (T> or =T_{c}+0.5 degrees C) . This indicates that the behavior of the soft mode for this temperature domain is dominated rather by thermal effects than by the network. A simple phenomenological approach was proposed to explain the behavior of the soft-mode dielectric strength versus polymer concentration. This model takes into account the anisotropic interaction between the polymer network and the liquid crystal, and the elastic interaction resulting from the anchoring of the liquid crystal molecules at the polymer surfaces. The experimental results are in agreement with the proposed model.
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Affiliation(s)
- Mohamed Petit
- Laboratoire de Thermophysique de la Matière Condensée-Equipe de l' UMR-CNRS 8024, Université du Littoral Côte d'Opale, 145, Avenue Maurice Schumann, 59140 Dunkerque, France
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Vieira S, Costa A, Rieder M. Crit Care 2003; 7:P176. [DOI: 10.1186/cc2065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Borecký J, Maia IG, Costa AD, Jezek P, Chaimovich H, de Andrade PB, Vercesi AE, Arruda P. Functional reconstitution of Arabidopsis thaliana plant uncoupling mitochondrial protein (AtPUMP1) expressed in Escherichia coli. FEBS Lett 2001; 505:240-4. [PMID: 11566183 DOI: 10.1016/s0014-5793(01)02835-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The Arabidopsis thaliana uncoupling protein (UCP) gene was expressed in Escherichia coli and isolated protein reconstituted into liposomes. Linoleic acid-induced H+ fluxes were sensitive to purine nucleotide inhibition with an apparent K(i) (in mM) of 0.8 (GDP), 0.85 (ATP), 0.98 (GTP), and 1.41 (ADP); the inhibition was pH-dependent. Kinetics of AtPUMP1-mediated H+ fluxes were determined for lauric, myristic, palmitic, oleic, linoleic, and linolenic acids. Properties of recombinant AtPUMP1 indicate that it represents a plant counterpart of animal UCP2 or UCP3. This work brings the functional and genetic approaches together for the first time, providing strong support that AtPUMP1 is truly an UCP.
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Affiliation(s)
- J Borecký
- Department of Membrane Transport Biophysics, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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Abstract
Evidence has been provided that the plant uncoupling proteins (pUCP) play basic physiological roles similar to the other uncoupling protein subfamily members (mammalian UCP1,2,3,4 and BMCP) and are effective in the situations of slight uncoupling that leads to: (1) accelerated respiration and metabolic rates that are beneficial to plant growth and development; (2) decreased formation of reactive oxygen species in mitochondria; and, (3) mild thermogenesis, inevitably accompanying the previous two phenomena. Hypothetically, specific physiological roles of pUCP such as cut off of ATP synthesis could be manifested in connection with climacteric respiratory rise during fruit ripening, seed dormancy, and plant senescence. pUCP might also facilitate growth under low temperatures, e.g., during seed germination or in roots. The existence of these specific roles is suggested by the immunochemical and functional localization of pUCP in mitochondria of fruits, seeds and roots of various plant species.
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Affiliation(s)
- P Jezek
- Department of Membrane Transport Biophysics, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague
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Costa A, Moritz R, Matos J, Machado F. Crit Care 2001; 5:P82. [DOI: 10.1186/cc1415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Abstract
Chemical modifications were used to identify some of the functionally important amino acid residues of the potato plant uncoupling protein (StUCP). The proton-dependent swelling of potato mitochondria in K(+)-acetate in the presence of linoleic acid and valinomycin was inhibited by mersalyl (K(i) = 5 microM) and other hydrophilic SH reagents such as Thiolyte MB, iodoacetate and 5, 5'-dithio-bis-(2-nitrobenzoate), but not by hydrophobic N-ethylmaleimide. This pattern of inhibition by SH reagents was similar to that of brown adipose tissue uncoupling protein (UCP1). As with UCP1, the arginine reagent 2,3-butadione, but not N-ethylmaleimide or other hydrophobic SH reagents, prevented the inhibition of StUCP-mediated transport by ATP in isolated potato mitochondria or with reconstituted StUCP. The results indicate that the most reactive amino acid residues in UCP1 and StUCP are similar, with the exception of N-ethylmaleimide-reactive cysteines in the purine nucleotide-binding site.
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Affiliation(s)
- P Jezek
- Department of Membrane Transport Biophysics, Institute of Physiology, Academy of Science, Prague, Czech Republic
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Costa AD, Nantes IL, Jezek P, Leite A, Arruda P, Vercesi AE. Plant uncoupling mitochondrial protein activity in mitochondria isolated from tomatoes at different stages of ripening. J Bioenerg Biomembr 1999; 31:527-33. [PMID: 10653480 DOI: 10.1023/a:1005408809619] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In the present study we have observed a higher state of coupling in respiring mitochondria isolated from green as compared to red tomatoes (Lycopersicon esculentum, Mill.). Green tomato mitochondria produced a membrane potential (deltapsi) high enough to phosphorylate ADP, whereas in red tomato mitochondria, BSA and ATP were required to restore deltapsi to the level of that obtained with green tomato mitochondria. This supports the notion that such uncoupling in red tomato mitochondria is mediated by a plant uncoupling mitochondrial protein (PUMP; cf. Vercesi et al., 1995). Nevertheless, mitochondria from both green and red tomatoes exhibited an ATP-sensitive linoleic acid (LA)-induced deltapsi decrease providing evidence that PUMP is also present in green tomatoes. Indeed, proteoliposomes containing reconstituted green or red tomato PUMP showed LA uniport and LA-induced H+ transport. It is suggested that the higher concentration of free fatty acids (PUMP substrates) in red tomatoes could explain the lower coupling state in mitochondria isolated from these fruits.
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Affiliation(s)
- A D Costa
- Departamento de Patologia Clínica (NMCE), Faculdade de Ciências Médicas, Universidade Estadual de Campinas, SP, Brazil
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Jezek P, Engstová H, Zácková M, Vercesi AE, Costa AD, Arruda P, Garlid KD. Fatty acid cycling mechanism and mitochondrial uncoupling proteins. Biochim Biophys Acta 1998; 1365:319-27. [PMID: 9693744 DOI: 10.1016/s0005-2728(98)00084-x] [Citation(s) in RCA: 144] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We hypothesize that fatty acid-induced uncoupling serves in bioenergetic systems to set the optimum efficiency and tune the degree of coupling of oxidative phosphorylation. Uncoupling results from fatty acid cycling, enabled by several phylogenetically specialized proteins and, to a lesser extent, by other mitochondrial carriers. It is suggested that the regulated uncoupling in mammalian mitochondria is provided by uncoupling proteins UCP-1, UCP-2 and UCP-3, whereas in plant mitochondria by PUMP and StUCP, all belonging to the gene family of mitochondrial carriers. UCP-1, and hypothetically UCP-3, serve mostly to provide nonshivering thermogenesis in brown adipose tissue and skeletal muscle, respectively. Fatty acid cycling was documented for UCP-1, PUMP and ADP/ATP carrier, and is predicted also for UCP-2 and UCP-3. UCP-1 mediates a purine nucleotide-sensitive uniport of monovalent unipolar anions, including anionic fatty acids. The return of protonated fatty acid leads to H+ uniport and uncoupling. UCP-2 is probably involved in the regulation of body weight and energy balance, in fever, and defense against generation of reactive oxygen species. PUMP has been discovered in potato tubers and immunologically detected in fruits and corn, whereas StUCP has been cloned and sequenced froma a potato gene library. PUMP is supposed to act in the termination of synthetic processes in mature fruits and during the climacteric respiratory rise.
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Affiliation(s)
- P Jezek
- Department of Membrane Transport Biophysics, Academy of Sciences of the Czech Republic, Prague.
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Kowaltowski AJ, Costa AD, Vercesi AE. Activation of the potato plant uncoupling mitochondrial protein inhibits reactive oxygen species generation by the respiratory chain. FEBS Lett 1998; 425:213-6. [PMID: 9559650 DOI: 10.1016/s0014-5793(98)00231-2] [Citation(s) in RCA: 127] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A variety of plant tissues contain an uncoupling mitochondrial protein (PUMP), recently described and characterized by our group. In this study we show that the inhibition of PUMP activity in potato tuber mitochondria significantly increases mitochondrial H2O2 generation, while PUMP substrates, such as linoleic acid, reduce mitochondrial H2O2 generation. This H2O2 generation occurred mainly by the dismutation of superoxide radicals formed through monoelectronic reduction of O2 by semiquinone forms of coenzyme Q. The results presented suggest that protection against mitochondrial oxidative stress may be a physiological role of PUMP.
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Affiliation(s)
- A J Kowaltowski
- Departamento de Patologia Clinica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, SP, Brazil
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Jezek P, Costa AD, Vercesi AE. Reconstituted plant uncoupling mitochondrial protein allows for proton translocation via fatty acid cycling mechanism. J Biol Chem 1997; 272:24272-8. [PMID: 9305881 DOI: 10.1074/jbc.272.39.24272] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Potato and tomato plant uncoupling mitochondrial protein (PUMP) was reconstituted into liposomes, and K+ or H+ fluxes associated with fatty acid (FA)-induced ion movement were measured using fluorescent ion indicators potassium binding benzofuraneisophthalate and 6-methoxy-N-(3-sulfopropyl)-quinolinium. We suggest that PUMP, like its mammalian counterpart, the uncoupling protein of brown adipose tissue mitochondria (Garlid, K. D., Orosz, D. E., Modrianský, M., Vassanelli, S., and Jeek, P. (1996), J. Biol. Chem. 271, 2615-2702), allows for H+ translocation via a FA cycling mechanism. Reconstituted PUMP translocated anionic linoleic and heptylbenzoic acids, undecanesulfonate, and hexanesulfonate, but not phenylvaleric and abscisic acids or Cl-. Transport was inhibited by ATP and GDP. Internal acidification of protein-free liposomes by linoleic or heptylbenzoic acid indicated that H+ translocation occurs by FA flip-flopping across the lipid bilayer. However, addition of valinomycin after FA-initiated GDP-sensitive H+ efflux solely in proteoliposomes, indicating that influx of anionic FA via PUMP precedes a return of protonated FA carrying H+. Phenylvaleric acid, unable to flip-flop, was without effect. Kinetics of FA and undecanesulfonate uniport suggested the existence of an internal anion binding site. Exponential flux-voltage characteristics were also studied. We suggest that regulated uncoupling in plant mitochondria may be important during fruit ripening, senescence, and seed dormancy.
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Affiliation(s)
- P Jezek
- Department of Membrane Transport Biophysics, Institute of Physiology, Academy of Sciences, 14220 Prague 4, Czech Republic.
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Gadelha FR, Thomson L, Fagian MM, Costa AD, Radi R, Vercesi AE. Ca2+-independent permeabilization of the inner mitochondrial membrane by peroxynitrite is mediated by membrane protein thiol cross-linking and lipid peroxidation. Arch Biochem Biophys 1997; 345:243-50. [PMID: 9308896 DOI: 10.1006/abbi.1997.0259] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Peroxynitrite anion, the reaction product of superoxide and nitric oxide, is a potent biological oxidant, which inactivates mammalian heart mitochondrial NADH-coenzyme Q reductase (complex I), succinate dehydrogenase (complex II), and ATPase, without affecting cytochrome c oxidase (complex IV). In this paper, we evaluated the effect of peroxynitrite on mitochondrial membrane integrity and permeability under low calcium concentration. Phosphate buffer was used in most of our experiments since Hepes, Tris, mannitol, and sucrose were found to inhibit the oxidative chemistry of peroxynitrite. Peroxynitrite (0.1-1.0 mM) caused a dose-dependent decrease in the ability of mitochondria to build up a membrane potential when N,N,N',N'-tetramethyl-p-phenylenediamine/ascorbate were used as substrate. Elimination of the membrane potential was accompanied by penetration of the osmotic support (KCl/NaCl) into the matrix as judged by the parallel occurrence of mitochondrial swelling. This swelling was partially inhibited by dithiothreitol (DTT) or butylated hydroxytoluene (BHT) and was insensitive to ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid, ADP, and cyclosporin A. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of solubilized membrane proteins indicated that alterations in membrane permeability were associated with the production of protein aggregates due to membrane protein thiol cross-linking. The protective effect of DTT on both mitochondrial swelling and protein polymerization suggests the involvement of disulfide bonds in the membrane permeabilization process. In addition, the increase in thiobarbituric acid-reactive substances and the partial inhibitory effect of BHT indicate the occurrence of lipid peroxidation. These results support the idea that under our experimental conditions peroxynitrite causes mitochondrial structural and functional alterations by Ca2+-independent mechanisms through lipid peroxidation and protein sulfhydryl oxidation.
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Affiliation(s)
- F R Gadelha
- Departamento de Bioquímica, Instituto de Biologia, Universidade Estadual de Campinas, SP, Brazil
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Abstract
Transport properties of plant mitochondria from potato tubers were investigated using the swelling technique and membrane potential measurements. Proton-dependent swelling of fatty acid-depleted mitochondria in potassium acetate with valinomycin was possible only in the presence of fatty acids (linoleic acid and 12-(4-azido-2-nitrophenylamino)dodecanoic acid) and was inhibited by various purine nucleotides including ATP, GDP, and GTP. Swelling representing uptake of hexanesulfonate was also inhibited by purine nucleotides. Also, the membrane potential of fatty acid-depleted potato mitochondria energized by succinate declined upon the addition of linoleic acid or 12-(4-azido-2-nitrophenylamino)dodecanoic acid, and this decrease was prevented by ATP and other purine nucleotides. These transport activities are identical to those reported for brown adipose tissue mitochondria and related to the uncoupling protein; therefore, we ascribed them to the plant mitochondrial uncoupling protein (PUMP). A major difference between plant and mammalian uncoupling protein is that PUMP transports small hydrophilic anions such as Cl- very slowly, if at all. We suggest that PUMP may play an important role in plant physiology, where a regulated uncoupling and thermogenesis can proceed during fruit and seed development.
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Affiliation(s)
- P Jezek
- Department of Membrane Transport Biophysics, Institute of Physiology, Academy of Sciences, 14220 Prague 4, Czech Republic
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Abstract
Ethical values of 171 college students at California State University, Chico, were measured, using a subset of the Rokeach (1968, 1971) Value Survey. Nonparametric statistical analysis, four value measures, and four different consistent tests of significance and probability showed, surprisingly, that the younger students were more ethical than the older students. College students under 21 scored significantly higher ethically on three out of the four measures. Younger college students valued equality, freedom, and honesty more than their older classmates did. Surprisingly also, the younger students were significantly more concerned with being helpful and intellectual and were less involved in pursuing an exciting life and in social recognition than were the older students.
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Affiliation(s)
- A Sikula
- Department of Management, California State University, Chico 95929-0031
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de Oliveira AT, Rabelo LM, Costa AD, Lessa I. [Characteristics of the demand for cranial computerized tomography: reasons and costs of the exam]. Arq Neuropsiquiatr 1992; 50:91-8. [PMID: 1307485 DOI: 10.1590/s0004-282x1992000100016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
It was reviewed a series of 2860 cerebral computed tomography (CCT) in order to compare the main reasons at referral to investigation with the CCT results and the costs with normal and abnormal CCT. It was also studied the age and sex of the patients. Data were collected from one out of three diagnostic centers in Salvador, Brasil, for a three years period. The 2860 CCT exclude all investigation carried out for the follow-up of a previously diagnosed abnormality. CCT abnormalities were detected in 1152 (40.3%). The following reasons showed the highest proportion of abnormal CCT, for males and females respectively: demential syndrome (91.7 and 83.3%); cerebrovascular accidents (85.1 and 73.6%); infectious and parasitary diseases (76.5 and 78.6%); tumors (65.8 and 55.4%); and head injuries, 63.6% for males. In the female group, 65.0% of the CCT were normal, in a range of 65.0 to 80.0% for the age groups under 54 years old. In the male group, the highest proportion of normal CCT was found in the age groups: 25-34 (68.4%), < 15 (62.9%) and 35-44 (62.7%). The most common reasons for normal CCT for males and females were: headache (81.3 and 87.5%); dizziness/vertigo (79.3 and 78.6%); seizures (67.3 and 70.0%); psychomotor deficiency (72.0 and 67.7%) and "endocrine disorders", 75.0% for each sex. The highest proportion of normal CCT (65.3%) was requested by medical "convenios". The cost with normal CCT reached US$565,225 and with the abnormal ones, US$381,247. Costs with normal CCT were 2.2 higher for medical "convenios" as compared to those of the National Institute of Security requests and 2.8 more than those of private medicine.
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Costa AD, Anzai A, Neto JB, Ikeda J. [Use of calcium hydroxide in the treatment of teeth with periapical lesions: clinical observation of 13 cases]. Rev Assoc Paul Cir Dent 1981; 35:220-6. [PMID: 6943624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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