25 results on '"Benmansour S"'
Search Results
2. On Nonlocal Elliptic Problems of the Kirchhoff Type Involving the Hardy Potential and Critical Nonlinearity.
- Author
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El Mokhtar, M. E. O., Benmansour, S., and Matallah, A.
- Abstract
In this article, we deal with the nonlocal elliptic problems of the Kirchhoff type involving the Hardy potential and critical nonlinearity on a bounded domain in R 3 . Under an appropriate condition on the nonhomogeneous term and using variational methods, we obtain two distinct solutions. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. Solvent-tuned ultrasonic synthesis of 2D coordination polymer nanostructures and flakes
- Author
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European Commission, Generalitat de Catalunya, Agencia Estatal de Investigación (España), La Caixa, Pepió, Belén, Contreras-Pereda, Noemí, Suárez-García, Salvio, Hayati, Payam, Benmansour, S., Retailleau, Pascal, Morsali, Ali, Ruiz Molina, Daniel, European Commission, Generalitat de Catalunya, Agencia Estatal de Investigación (España), La Caixa, Pepió, Belén, Contreras-Pereda, Noemí, Suárez-García, Salvio, Hayati, Payam, Benmansour, S., Retailleau, Pascal, Morsali, Ali, and Ruiz Molina, Daniel
- Abstract
Herein, a new 2-dimensional coordination polymer based on copper (II), {Cu(L)(DMF)}, where L stands for 1,2,4,5-benzenetetracarboxylate (complex 1) is synthesized. Interestingly, we demonstrate that both solvent and sonication are relevant in the top-down fabrication of nanostructures. Water molecules are intercalated in suspended crystals of complex 1 modifying not only the coordination sphere of Cu(II) ions but also the final chemical formula and crystalline structure obtaining {[Cu(L)(HO)]·HO} (complex 2). On the other hand, ultrasound is required to induce the nanostructuration. Remarkably, different morphologies are obtained using different solvents and interconversion from one morphology to another seems to occur upon solvent exchange. Both complexes 1 and 2, as well as the corresponding nanostructures, have been fully characterized by different means such as infrared spectroscopy, x-ray diffraction and microscopy.
- Published
- 2021
4. Correction to: miRNA-23b as a biomarker of culture-positive neonatal sepsis
- Author
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Fatmi A, Rebiahi S, Chabni N, Zerrouki H, Azzaoui H, Elhabiri Y, Benmansour S, Ibanez-Cabellos J, Smahi M, Aribi M, Garcia-Gimenez J, and Pallardo F
- Published
- 2020
5. Delamination of 2D coordination polymers: The role of solvent and ultrasound
- Author
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Agencia Estatal de Investigación (España), Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Generalitat de Catalunya, Generalitat Valenciana, La Caixa, Ministerio de Economía, Industria y Competitividad (España), Contreras-Pereda, Noemí, Hayati, Payam, Suárez-García, Salvio, Esrafili, P., Retailleau, Pascal, Benmansour, S., Novio, Fernando, Morsali, Ali, Ruiz Molina, Daniel, Agencia Estatal de Investigación (España), Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Generalitat de Catalunya, Generalitat Valenciana, La Caixa, Ministerio de Economía, Industria y Competitividad (España), Contreras-Pereda, Noemí, Hayati, Payam, Suárez-García, Salvio, Esrafili, P., Retailleau, Pascal, Benmansour, S., Novio, Fernando, Morsali, Ali, and Ruiz Molina, Daniel
- Abstract
Two novel cadmium-based 2D coordination polymers have been synthesized and characterized. Experimental results evidence that the best delamination processes occurs when weak interactions dominate the cohesion between layers and solvent molecules are occluded within the crystalline network. In this case, the delamination of the crystals occurs spontaneously in water. On top of that, and thanks to the high stability of the resulting (flake) colloidal dispersions, we have completed a detailed study of the sonication assisted delamination impact by: I) comparison of two different sonication approaches (bath vs. tip sonication) and II) optimization of final flake morphology and yield by controlling solvent and sonication time. Our results definitely pave the way for the fabrication and implementation of 2D coordination polymers using ultrasound.
- Published
- 2019
6. Static and dynamic interaction between pi and d electrons in organic superconductor beta '-(BEDT-TTF)(4)[(H3O)Fe(C2O4)(3)] center dot C6H5Br studied by C-13 NMR spectroscopy
- Author
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Ihara, Y., Futami, Y., Kawamoto, A., Matsui, K., Goto, T., Sasaki, T., Benmansour, S., Gomez-Garcia, C. J., Ihara, Y., Futami, Y., Kawamoto, A., Matsui, K., Goto, T., Sasaki, T., Benmansour, S., and Gomez-Garcia, C. J.
- Abstract
We present the results of C-13 NMR experiments in an organic superconductor with localized Fe spins beta ''-(BEDT-TTF)(4)[(H3O)Fe(C2O4)(3)] center dot C6H5Br. We reveal the antiferromagnetic coupling between Fe d spins and pi spins, which creates an exchange field antiparallel to the external field direction at the pi electrons. In addition to the static effects of Fe spins, we show from the nuclear spin-lattice relaxation rate measurement that the magnetic fluctuations generated by Fe spins are suppressed at low temperatures and high magnetic fields. These conditions are suitable to stabilize the field-induced superconductivity by the field compensation mechanism. After the suppression of Fe-spin dynamics by a magnetic field of 19 T, we observed the underlying pi-electron contribution. We discuss a possible anomaly in the pi-electron system.
- Published
- 2016
7. Solvent Modulated Assembly of Two Ni(II) Complexes: Syntheses, Structures and Magnetic Properties
- Author
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Vinayak, R, Harinath, A, Gómez-García, C J, Panda, Tarun K, Benmansour, S, Nayek, H P, Vinayak, R, Harinath, A, Gómez-García, C J, Panda, Tarun K, Benmansour, S, and Nayek, H P
- Abstract
A dinuclear [Ni2(L)2(DMSO)2(MeOH)2] (1) and a tetra-nuclear [Ni4(L)4(DMF)2(H2O)2].DMF (2) Ni(II) complexes have been prepared by treating nickel nitrate hexahydrate with the Schiff base ligand H2L (H2L=(E)-2-(2-hydroxybenzyliden)amino-4-nitrophenol) in a one-pot reaction. Complex 1 was obtained after recrystallization of the precipitate from the reaction with a 1:1:1 mixture of DMSO/CH2Cl2/MeOH. In contrast, the tetrameric complex 2 was obtained after slow evaporation of the filtrate. Both complexes were characterized by analytical, thermogravimetric, optical and magnetic techniques. The solid state molecular structures of 1 and 2 were determined by single crystal X-ray crystallography. Complex 1 shows a dinuclear structure whereas complex 2 shows a defective dicubane structure. The magnetic properties of complex 1 show a predominant ferromagnetic coupling between the Ni(II) ions with J=+16.1 cm−1 and 2 shows a predominant Ni−Ni antiferromangetic interaction of J=-15.5 cm−1. Both coupling constants are the expected ones from magneto-structural correlations. The thermal stability and optical properties of both complexes have also been investigated.
- Published
- 2016
8. Electrical Conductivity and Strong Luminescence in Copper Iodide Double Chains with Isonicotinato Derivatives
- Author
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Hassanein K., Conesa-Egea J., Delgado S., Castillo O., Benmansour S., Martínez J.I., Abellán G., Gómez-García C.J., Zamora F., Amo-Ochoa P., Hassanein K., Conesa-Egea J., Delgado S., Castillo O., Benmansour S., Martínez J.I., Abellán G., Gómez-García C.J., Zamora F., and Amo-Ochoa P.
- Published
- 2015
9. Reversible stimulus-responsive Cu(i) iodide pyridine coordination polymer
- Author
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Ministerio de Ciencia e Innovación (España), Ministerio de Economía y Competitividad (España), Eusko Jaurlaritza, Generalitat Valenciana, Consejo Superior de Investigaciones Científicas (España), Amo-Ochoa, Pilar, Hassanein, K., Gómez-García, Carlos J., Benmansour, S., Perles, J., Castillo, Óscar, Martínez, José I., Ocón, P., Zamora, F., Ministerio de Ciencia e Innovación (España), Ministerio de Economía y Competitividad (España), Eusko Jaurlaritza, Generalitat Valenciana, Consejo Superior de Investigaciones Científicas (España), Amo-Ochoa, Pilar, Hassanein, K., Gómez-García, Carlos J., Benmansour, S., Perles, J., Castillo, Óscar, Martínez, José I., Ocón, P., and Zamora, F.
- Abstract
We present a structurally flexible copper-iodide-pyridine-based coordination polymer showing drastic variations in its electrical conductivity driven by temperature and sorption of acetic acid molecules. The dramatic effect on the electrical conductivity enables the fabrication of a simple and robust device for gas detection. X-ray diffraction studies and DFT calculations allow the rationalisation of these observations.
- Published
- 2015
10. Electrical conductivity and strong luminescence in copper Iodide double chains with isonicotinato derivatives
- Author
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Ministerio de Ciencia e Innovación (España), European Commission, Universidad Autónoma de Madrid, Consejo Superior de Investigaciones Científicas (España), Eusko Jaurlaritza, Ministerio de Economía y Competitividad (España), Generalitat Valenciana, Hassanein, K., Conesa-Egea, J., Delgado, S., Castillo, Óscar, Benmansour, S., Martínez, José I., Abellán, G., Gómez-García, Carlos J., Zamora, F., Amo-Ochoa, Pilar, Ministerio de Ciencia e Innovación (España), European Commission, Universidad Autónoma de Madrid, Consejo Superior de Investigaciones Científicas (España), Eusko Jaurlaritza, Ministerio de Economía y Competitividad (España), Generalitat Valenciana, Hassanein, K., Conesa-Egea, J., Delgado, S., Castillo, Óscar, Benmansour, S., Martínez, José I., Abellán, G., Gómez-García, Carlos J., Zamora, F., and Amo-Ochoa, Pilar
- Abstract
Direct reactions between CuI and isonicotinic acid (HIN) or the corresponding esters, ethyl isonicotinate (EtIN) or methyl isonicotinate (MeIN), give rise to the formation of the coordination polymers [CuI(L)] with L=EtIN (1), MeIN (2) and HIN (3). Polymers 1-3 show similar structures based on a CuI double chain in which ethyl-, methyl isonicotinate or isonicotinic acid are coordinated as terminal ligands. Albeit, their supramolecular architecture differs considerably, affecting the distances and angles of the central CuI double chains and thereby their physical properties. Hence, the photoluminescence shows remarkable differences; 1 and 2 show a strong yellow emission, whereas 3 displays a weak emission; and 1 and 2 are semiconductors with moderate room temperature conductivities, whereas 3 has increased electrical conductivity up to 3×10 S cm. Additionally, 1 and 2 present an irreversible transition to a highly conducting phase with a conductivity almost 4 orders of magnitude higher and a quasi-metallic behaviour. Thermogravimetric analysis (TGA) coupled to a mass spectrometer and magnetic measurements point to a partial thermally induced oxidation of the carboxylate groups of the ligands with Cu to Cu reduction. DFT calculations have been carried out to rationalise these observations.
- Published
- 2015
11. Delayed pharmacological effects of antidepressants
- Author
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Frazer, A, primary and Benmansour, S, additional
- Published
- 2002
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12. Nutrient intake in a cohort of 9-month-old infants in the district of Tlemcen (Northwest of Algeria).
- Author
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Smahi, M. C., Benmansour, S. A., Hadj-Kacem, A., Ghomari, S. M., Grangaud, J. P., and Touhami, M.
- Subjects
- *
INFANT nutrition , *FOOD consumption , *MICRONUTRIENTS - Abstract
Objective: To investigate food and nutrient intakes in 9-month-old infants. Design: Cross-sectional survey, including 24-hour dietary recalls of infants food and nutrient intakes, as reported by parents. Material and methods: 378 infants (9 months old completed, singleton, born at term in the district of Tlemcen, birth weight a 2,500 grams) were randomly recruited at the time of vaccination against measles, from the 9 immunization's centers in the district of Tlemcen, between 29/11/2007 and 14/10/2008, after parents signed consent. Diet was assessed using a structured 24-hour food recall. Data collection and statistical analyses were performed using Nutri-survey 2007 and SPSS statistics 17.0. In the absence of national guidelines, nutrient intakes were compared with dietary recommended nutritional intakes (RNI) or the Dietary Refe-rence Intakes (DRIs). Results: Globally, all mean macronutrient nutrient intakes, met dietary recommended nutritional intakes. However, daily intakes of some micronutrients (folie acid, vitamin A, vitamin C, zinc and especially iron) were below recommendations. Thus, consi-dering a 10% bioavailability level, 38.1 % of the subjeets had iron intakes less than the recommended nutrient intake and 80% lessthan RNI X 0.77. Conclusions: Daily intakes of micronutrients, especially iron, must be improved. [ABSTRACT FROM AUTHOR]
- Published
- 2012
13. Maternal immune activation during pregnancy is associated with more difficulties in socio-adaptive behaviors in autism spectrum disorder.
- Author
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Ellul P, Maruani A, Vantalon V, Humeau E, Amestoy A, Anchordoqui A, Atzori P, Baleyte JM, Benmansour S, Bonnot O, Bouvard M, Cartigny A, Coulon N, Coutelle R, Da Fonseca D, Demily C, Givaudan M, Gollier-Briant F, Guénolé F, Koch A, Leboyer M, Lefebvre A, Lejuste F, Levy C, Mendes E, Robert N, Schroder CM, Speranza M, Zante E, Peyre H, Rosenzwajg M, Klatzmann D, Tchitchek N, and Delorme R
- Subjects
- Pregnancy, Female, Humans, Retrospective Studies, Prospective Studies, Adaptation, Psychological, Autism Spectrum Disorder, Prenatal Exposure Delayed Effects
- Abstract
Autism spectrum disorder (ASD) are neurodevelopmental conditions characterised by deficits in social communication and interaction and repetitive behaviours. Maternal immune activation (MIA) during the mid-pregnancy is a known risk factor for ASD. Although reported in 15% of affected individuals, little is known about the specificity of their clinical profiles. Adaptive skills represent a holistic approach to a person's competencies and reflect specifically in ASD, their strengths and difficulties. In this study, we hypothesised that ASD individual with a history of MIA (MIA
+ ) could be more severely socio-adaptively impaired than those without MIA during pregnancy (MIA- ). To answer this question, we considered two independent cohorts of individuals with ASD (PARIS study and FACE ASD) screened for pregnancy history, and used supervised and unsupervised machine learning algorithms. We included 295 mother-child dyads with 14% of them with MIA+ . We found that ASD-MIA+ individuals displayed more severe maladaptive behaviors, specifically in their socialization abilities. MIA+ directly influenced individual's socio-adaptive skills, independent of other covariates, including ASD severity. Interestingly, MIA+ affect persistently the socio-adaptive behavioral trajectories of individuals with ASD. The current study has a retrospective design with possible recall bias regarding the MIA event and, even if pooled from two cohorts, has a relatively small population. In addition, we were limited by the number of covariables available potentially impacted socio-adaptive behaviors. Larger prospective study with additional dimensions related to ASD is needed to confirm our results. Specific pathophysiological pathways may explain these clinical peculiarities of ASD- MIA+ individuals, and may open the way to new perspectives in deciphering the phenotypic complexity of ASD and for the development of specific immunomodulatory strategies., (© 2023. Springer Nature Limited.)- Published
- 2023
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14. Solvent-tuned ultrasonic synthesis of 2D coordination polymer nanostructures and flakes.
- Author
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Pepió B, Contreras-Pereda N, Suárez-García S, Hayati P, Benmansour S, Retailleau P, Morsali A, and Ruiz-Molina D
- Abstract
Herein, a new 2-dimensional coordination polymer based on copper (II), {Cu
2 (L)(DMF)2 }n , where L stands for 1,2,4,5-benzenetetracarboxylate (complex 1) is synthesized. Interestingly, we demonstrate that both solvent and sonication are relevant in the top-down fabrication of nanostructures. Water molecules are intercalated in suspended crystals of complex 1 modifying not only the coordination sphere of Cu(II) ions but also the final chemical formula and crystalline structure obtaining {[Cu(L)(H2 O)3 ]·H2 O}n (complex 2). On the other hand, ultrasound is required to induce the nanostructuration. Remarkably, different morphologies are obtained using different solvents and interconversion from one morphology to another seems to occur upon solvent exchange. Both complexes 1 and 2, as well as the corresponding nanostructures, have been fully characterized by different means such as infrared spectroscopy, x-ray diffraction and microscopy., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)- Published
- 2021
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15. Stroke knowledge among emergency centre visitors: A cross-sectional multicenter survey.
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Chakroun-Walha O, Samet A, Ben Abdallah M, Benmansour S, Issaoui F, Rebai M, Ben Messaoud K, Benali C, Mokni W, Nasri A, Rejeb I, and Rekik N
- Abstract
Introduction: Stroke is a public health problem worldwide. Community stroke knowledge is crucial to guide the prevention approach. We aimed to evaluate the level of stroke knowledge among the visitors to Emergency Centres (ECs) in the southern region of Tunisia concerning factors of risk, symptoms, and treatment of stroke., Methods: A multicenter cross-sectional survey about stroke knowledge; conducted in five ECs for 10 days. All the visitors to these ECs were invited to participate in this survey. In each center, one investigator had to conduct the questionnaire. We used the stroke knowledge test (SKT)., Results: We enrolled 839 participants aged at 44 ± 7 years and with an M/F sex-ratio at 0.9. Relatives and mass media were the most reported sources of information about stroke. In 32.3% of cases, the participants had a university schooling level. The upper quartile had an SKT score of 55% or over (n = 247; 29.4%). The SKT score was significantly higher in young, female participants, in rural centers, with a university level of schooling and with no reported chronic diseases. Receiving information about stroke through the medium of television or via relatives was an independent predictor of a high SKT score compared with other knowledge sources., Conclusion: This study emphasises the urgent need for improving the population's knowledge about stroke in Tunisia. These findings may reflect the lack of government policies for education and training on stroke. A national educating program is necessary to implement to increase stroke knowledge., Competing Interests: The authors declared no conflict of interest., (© 2018 Published by Elsevier Ltd. CC BY-NC-ND 4.0.)
- Published
- 2021
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16. Slow Relaxation of the Magnetization in Anilato-Based Dy(III) 2D Lattices.
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Benmansour S, Hernández-Paredes A, Bayona-Andrés M, and Gómez-García CJ
- Subjects
- Models, Molecular, Molecular Structure, Benzoquinones chemistry, Coordination Complexes chemistry, Dysprosium chemistry
- Abstract
The search for two- and three-dimensional materials with slow relaxation of the magnetization (single-ion magnets, SIM and single-molecule magnets, SMM) has become a very active area in recent years. Here we show how it is possible to prepare two-dimensional SIMs by combining Dy(III) with two different anilato-type ligands (dianions of the 3,6-disubstituted-2,5-dihydroxy-1,4-benzoquinone: C
6 O4 X2 2- , with X = H and Cl) in dimethyl sulfoxide (dmso). The two compounds prepared, formulated as: [Dy2 (C6 O4 H2 )3 (dmso)2 (H2 O)2 ]·2dmso·18H2 O ( 1 ) and [Dy2 (C6 O4 Cl2 )3 (dmso)4 ]·2dmso·2H2 O ( 2 ) show distorted hexagonal honeycomb layers with the solvent molecules (dmso and H2 O) located in the interlayer space and in the hexagonal channels that run perpendicular to the layers. The magnetic measurements of compounds 1 , 2 and [Dy2 (C6 O4 (CN)Cl)3 (dmso)6 ] ( 3 ), a recently reported related compound, show that the three compounds present slow relaxation of the magnetization. In compound 1 the SIM behaviour does not need the application of a DC field whereas 2 and 3 are field-induced SIM (FI-SIM) since they show slow relaxation of the magnetization when a DC field is applied. We discuss the differences observed in the crystal structures and magnetic properties based on the X group of the anilato ligands (H, Cl and Cl/CN) in 1 - 3 and in the recently reported derivative [Dy2 (C6 O4 Br2 )3 (dmso)4 ]·2dmso·2H2 O ( 4 ) with X = Br, that is also a FI-SIM.- Published
- 2021
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17. miRNA-23b as a biomarker of culture-positive neonatal sepsis.
- Author
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Fatmi A, Rebiahi SA, Chabni N, Zerrouki H, Azzaoui H, Elhabiri Y, Benmansour S, Ibáñez-Cabellos JS, Smahi MC, Aribi M, García-Giménez JL, and Pallardó FV
- Subjects
- Age Factors, Age of Onset, Blood Culture, Disease Susceptibility, Gene Expression Regulation, Humans, Infant, Newborn, MicroRNAs blood, MicroRNAs genetics, Neonatal Sepsis blood, Neonatal Sepsis epidemiology, Public Health Surveillance, Symptom Assessment, Biomarkers, Neonatal Sepsis diagnosis, Neonatal Sepsis etiology
- Abstract
Background: Neonatal sepsis remains an important cause of morbidity and mortality. The ability to quickly and accurately diagnose neonatal sepsis based on clinical assessments and laboratory blood tests remains difficult, where haemoculture is the gold standard for detecting bacterial sepsis in blood culture. It is also very difficult to study because neonatal samples are lacking., Methods: Forty-eight newborns suspected of sepsis admitted to the Neonatology Department of the Mother-Child Specialized Hospital of Tlemcen. From each newborn, a minimum of 1-2 ml of blood was drawn by standard sterile procedures for blood culture. The miRNA-23b level in haemoculture was evaluated by RT-qPCR., Results: miR-23b levels increased in premature and full-term newborns in early onset sepsis (p < 0.001 and p < 0.005 respectively), but lowered in late onset sepsis in full-term neonates (p < 0.05) compared to the respective negative controls. miR-23b levels also increased in late sepsis in the negative versus early sepsis negative controls (p < 0.05). miR-23b levels significantly lowered in the newborns who died from both sepsis types (p < 0.0001 and p < 0.05 respectively). In early sepsis, miR-23b and death strongly and negatively correlated (correlation coefficient = - 0.96, p = 0.0019). In late sepsis, miRNA-23b and number of survivors (correlation coefficient = 0.70, p = 0.506) positively correlated., Conclusions: Lowering miR-23b levels is an important factor that favours sepsis development, which would confirm their vital protective role, and strongly suggest that they act as a good marker in molecular diagnosis and patient monitoring.
- Published
- 2020
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18. Magnetic Properties of End-to-End Azide-Bridged Tetranuclear Mixed-Valence Cobalt(III)/Cobalt(II) Complexes with Reduced Schiff Base Blocking Ligands and DFT Study.
- Author
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Banerjee A, Banerjee S, Gómez García CJ, Benmansour S, and Chattopadhyay S
- Abstract
Two tetranuclear mixed-valence cobalt(III/II) complexes having the general formula [(μ
1,3 -N3 ){CoII (Ln )(μ-O2 CC6 H4 NO2 )CoIII (N3 )}2 ]PF6 (where H2 L1 and H2 L2 are two reduced Schiff base ligands) have been synthesized and characterized. The structures of both complexes show cobalt(II) and cobalt(III) centers with a distorted octahedral geometry with cobalt(III) and cobalt(II) centers located at the inner N2 O2 and outer O4 cavities of the reduced Schiff base ligands, respectively. The oxidation states of both cobalt centers have been confirmed by bond valence sum (BVS) calculations. The magnetic properties show that both compounds behave as cobalt(II) dimers connected through an end-to-end azido bridging ligand and show moderate antiferromagnetic Co(II)-Co(II) couplings of -11.0 and -14.4 cm-1 for 1 and 2 , respectively, as also corroborated by DFT calculations, Jtheo = -13.07 cm-1 for 1 and -12.49 cm-1 for 2 . The calculated spin densities of both complexes at the cobalt(II) centers are -2.75 and +2.75, respectively, clearly supporting that they are the magnetic centers., Competing Interests: The authors declare no competing financial interest., (Copyright © 2019 American Chemical Society.)- Published
- 2019
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19. Comparison of the Antidepressant-Like Effects of Estradiol and That of Selective Serotonin Reuptake Inhibitors in Middle-Aged Ovariectomized Rats.
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Benmansour S, Arroyo LD, and Frazer A
- Abstract
This study investigated the effect of age and that of the post-ovariectomy (OVX) time interval on the antidepressant (AD)-like effects of estradiol (E
2 ) and selective serotonin reuptake inhibitors (SSRIs) in middle-aged (10 month) OVX rats (10m-OVX). Acute or chronic effects of these treatments in 10m-OVX were compared with those (1) in young adult (4-month) OVX rats (4m-OVX) or with older (14-month) OVX rats (14m-OVX), at a short time: 2 weeks post-OVX (+2w) and (2) in 10m-OVX rats after a longer times: 4 or 8 months post-OVX (+4m or +8m). Using in vivo chronoamperometry in the CA3 region of the hippocampus, E2 at 20 pmol, a dose shown previously to inhibit the serotonin transporter (SERT) in 4m-OVX, had no effect in 10m-OVX+2w. A higher dose of E2 (40 pmol) increased T80 value, a measure of serotonin or 5-hydroxytryptamine (5-HT) clearance, and also blocked the ability of fluvoxamine to increase T80. By contrast, estradiol had no effects on SERT function in 10m-OVX+4m, even at a higher dose than 40 pmol. Fluvoxamine slowed 5-HT clearance in 10m-OVX at +2w, +4m and +8m post-OVX as it did in the 4m-OVX. Using the forced swim test, 2 weeks treatment with E2 (5 μg/day), a dose shown previously to induce AD-like effects in 4m-OVX, had no effect in 10m-OVX+2w. However, a higher dose (10 μg/day) of E2 induced an AD-like effect as demonstrated by significantly increased swimming behavior and decreased immobility. This effect was not seen in 10m-OVX+4m. By contrast, significant AD-like effects were obtained in 14m-OVX+2w, thereby demonstrating that the lack of an AD effect of E2 is due to the 4-month hormone withdrawal and not to an age effect. After 2 weeks treatment with the SSRI sertraline, similar AD-like effects were obtained in 10m-OVX tested at +2w, +4m or +8m post-OVX as those found in 4m-OVX. Thus, the potency of estradiol to produce effects consistent with inhibition of the SERT was not only decreased in older rats but its effects were markedly diminished the longer hormonal depletion occurred. By contrast, the ability of SSRIs to inhibit the SERT was not affected either by age or the length of hormonal depletion.- Published
- 2016
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20. A Heterobimetallic Anionic 3,6-Connected 2D Coordination Polymer Based on Nitranilate as Ligand.
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Benmansour S and Gómez-García CJ
- Abstract
In order to synthesize new coordination polymers with original architectures and interesting magnetic properties, we used the nitranilate ligand (C₆O₄(NO₂)₂
2- = C₆N₂O₈2- ), derived from the dianionic ligand dhbq2- (2,5-dihydroxy-1,4-benzoquinone = H₂C₆O₄2- ). The use of this bis-bidentate bridging ligand led to [(DAMS)₂{FeNa(C₆N₂O₈)₃}·CH₃CN]n (1) (DAMS⁺ = C16 H17 N₂⁺ = 4-[4-(dimethylamino)-α-styryl]-1-methylpyridinium), a 2D heterometallic coordination polymer presenting an unprecedented structure for any anilato-based compound. This structural type is a 3,6-connected 2D coordination polymer derived from the well-known honeycomb hexagonal structure, where Fe(III) ions alternate with Na⁺ dimers (as Na₂O12 units) in the vertices of the hexagons and with an additional [Fe(C₆N₂O₈)₃]3- anion located in the center of the hexagons connecting the three Na⁺ dimers. The magnetic properties of compound 1 show the presence of paramagnetic isolated high spin Fe(III) complexes with a zero field splitting, |D| = 8.5 cm-1 .- Published
- 2016
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21. Guest-dependent single-ion magnet behaviour in a cobalt(ii) metal-organic framework.
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Vallejo J, Fortea-Pérez FR, Pardo E, Benmansour S, Castro I, Krzystek J, Armentano D, and Cano J
- Abstract
Single-ion magnets (SIMs) are the smallest possible magnetic devices for potential applications in quantum computing and high-density information storage. Both, their addressing in surfaces and their organization in metal-organic frameworks (MOFs) are thus current challenges in molecular chemistry. Here we report a two-dimensional 2D MOF with a square grid topology built from cobalt(ii) SIMs as nodes and long rod-like aromatic bipyridine ligands as linkers, and exhibiting large square channels capable to host a large number of different guest molecules. The organization of the cobalt(ii) nodes in the square layers improves the magnetic properties by minimizing the intermolecular interactions between the cobalt(ii) centres. Moreover, the SIM behaviour was found to be dependent on the nature of the aromatic guest molecules. The whole process could be followed by single-crystal X-ray diffraction, providing comprehensive evidence of the putative role of the solvent guest molecules that leave a "fingerprint" on the 2D structures and thus, on the cobalt environment.
- Published
- 2016
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22. Signaling mechanisms involved in the acute effects of estradiol on 5-HT clearance.
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Benmansour S, Privratsky AA, Adeniji OS, and Frazer A
- Subjects
- Animals, CA3 Region, Hippocampal drug effects, CA3 Region, Hippocampal metabolism, Estrogen Receptor alpha agonists, Estrogen Receptor alpha metabolism, Estrogen Receptor beta agonists, Estrogen Receptor beta metabolism, Female, Fluvoxamine pharmacology, MAP Kinase Signaling System drug effects, Nitriles pharmacology, Ovariectomy, Phenols, Proto-Oncogene Proteins c-akt metabolism, Pyrazoles pharmacology, Rats, Rats, Sprague-Dawley, Receptor, IGF Type 1 metabolism, Receptor, trkB metabolism, Receptors, Metabotropic Glutamate metabolism, Serotonin Antagonists pharmacology, Serotonin Plasma Membrane Transport Proteins metabolism, Estradiol pharmacology, Estrogens pharmacology, Serotonin metabolism, Signal Transduction drug effects
- Abstract
Estradiol was found previously to have an antidepressant-like effect and to block the ability of selective serotonin reuptake inhibitors (SSRIs) to have an antidepressant-like effect. The antidepressant-like effect of estradiol was due to estrogen receptor β (ERβ) and/or GPR30 activation, whereas estradiol's blockade of the effect of an SSRI was mediated by ERα. This study focuses on investigating signaling pathways as well as interacting receptors associated with these two effects of estradiol. In vivo chronoamperometry was used to measure serotonin transporter (SERT) function. The effect of local application of estradiol or selective agonists for ERα (PPT) or ERβ (DPN) into the CA3 region of the hippocampus of ovariectomized (OVX) rats on 5-hydroxytryptamine (5-HT) clearance as well as on the ability of fluvoxamine to slow 5-HT clearance was examined after selective blockade of signaling pathways or that of interacting receptors. Estradiol- or DPN-induced slowing of 5-HT clearance mediated by ERβ was blocked after inhibition of MAPK/ERK1/2 but not of PI3K/Akt signaling pathways. This effect also involved interactions with TrkB, and IGF-1 receptors. Estradiol's or PPT's inhibition of the fluvoxamine-induced slowing of 5-HT clearance mediated by ERα, was blocked after inhibition of either MAPK/ERK1/2 or PI3K/Akt signaling pathways. This effect involved interactions with the IGF-1 receptor and with the metabotropic glutamate receptor 1, but not with TrkB. This study illustrates some of the signaling pathways required for the effects of estradiol on SERT function, and particularly shows that ER subtypes elicit different as well as common signaling pathways for their actions.
- Published
- 2014
- Full Text
- View/download PDF
23. Impact of ovarian hormones on the modulation of the serotonin transporter by fluvoxamine.
- Author
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Benmansour S, Piotrowski JP, Altamirano AV, and Frazer A
- Subjects
- Animals, Diestrus physiology, Estradiol blood, Estradiol pharmacology, Estrus physiology, Female, Hippocampus drug effects, Hippocampus metabolism, Male, Orchiectomy, Ovariectomy, Proestrus physiology, Progesterone blood, Rats, Rats, Sprague-Dawley, Serotonin pharmacokinetics, Serotonin Plasma Membrane Transport Proteins drug effects, Serum Albumin, Bovine pharmacology, Sex Characteristics, Time Factors, Estradiol analogs & derivatives, Fluvoxamine pharmacology, Progesterone pharmacology, Serotonin Plasma Membrane Transport Proteins metabolism, Selective Serotonin Reuptake Inhibitors pharmacology
- Abstract
Most preclinical studies examining the mechanism(s) of action of antidepressants are carried out using male animals. Blockade of serotonin transporter (SERT) function by selective serotonin reuptake inhibitors (SSRIs) is the initial event that triggers a not completely understood process that results in clinical improvement in depression. To investigate whether there are differences in the ability of SSRIs to inhibit the SERT between male and female rats at different phases of the estrous cycle, clearance of locally applied serotonin (5-HT) was measured by in vivo chronoamperometry. Local application of the SSRI, fluvoxamine, directly into the CA3 area of hippocampus increased significantly 5-HT clearance time parameters in male rats and female rats in estrus or diestrus, but not in proestrus. The contribution of ovarian steroids to this result was investigated in ovariectomized (OVX) rats treated with estradiol benzoate (EB) and/or progesterone (P). In OVX-control rats, fluvoxamine increased clearance time parameters, whereas EB and/or P treatment blocked this effect, consistent with what was seen in female rats in proestrus. This effect was gender-specific, since treatment of castrated rats with EB/P had no effect on the ability of fluvoxamine to slow 5-HT clearance. The time course of hormonal effects showed that 1-60 min after local application of 17-beta-estradiol (E(2)) into the CA3 region of OVX rats, fluvoxamine had no effect on clearance time of 5-HT. E(2)-BSA mimicked E(2)'s effects at 10 min but not at 60 min. Pretreatment with estrogen receptor antagonists blocked the effects of E(2). The finding that acutely both estradiol and progesterone can inhibit the ability of an SSRI to slow the clearance of 5-HT, may have important implications for the use of SSRIs in women.
- Published
- 2009
- Full Text
- View/download PDF
24. Serotonin clearance in vivo is altered to a greater extent by antidepressant-induced downregulation of the serotonin transporter than by acute blockade of this transporter.
- Author
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Benmansour S, Owens WA, Cecchi M, Morilak DA, and Frazer A
- Subjects
- Animals, Binding, Competitive drug effects, Carrier Proteins genetics, Dose-Response Relationship, Drug, Hippocampus drug effects, Hippocampus metabolism, In Situ Hybridization, Male, Membrane Glycoproteins genetics, RNA, Messenger analysis, RNA, Messenger metabolism, Raphe Nuclei metabolism, Rats, Rats, Sprague-Dawley, Serotonin pharmacokinetics, Serotonin Plasma Membrane Transport Proteins, Selective Serotonin Reuptake Inhibitors pharmacology, Sertraline pharmacology, Time, Antidepressive Agents pharmacology, Carrier Proteins antagonists & inhibitors, Carrier Proteins metabolism, Down-Regulation drug effects, Membrane Glycoproteins antagonists & inhibitors, Membrane Glycoproteins metabolism, Membrane Transport Proteins, Nerve Tissue Proteins, Serotonin metabolism
- Abstract
Serotonin uptake, mediated by the serotonin transporter (SERT), is blocked acutely by antidepressants such as the selective serotonin reuptake inhibitors (SSRIs), but such blockade does not correlate temporally with the onset of therapeutic improvement. Treatment with SSRIs for 21 d induced downregulation of the SERT (Benmansour et al., 1999). The time course of SERT downregulation as well as the time course for its recovery after cessation of treatment with the SSRI sertraline were investigated using tritiated cyanoimipramine to measure SERT binding sites. To determine if there was a temporal correlation between the time when sertraline induced downregulation of the SERT and when marked alteration in SERT function occurred, clearance of locally applied 5-HT into the CA3 region of hippocampus was achieved using in vivo electrochemistry. After 4 or 10 d treatment with sertraline, SERT binding sites decreased very little (15-30%), and the chronoamperometric signals for serotonin in sertraline-treated rats were comparable with ones obtained in control animals. By contrast, after 15 d of treatment, when SERT binding sites were markedly reduced by 80%, there was robust decrease in the clearance of 5-HT. Moreover, the functional consequences of SERT downregulation as measured by chronoamperometry were significantly greater than those seen after acute blockade of the SERT by SSRIs. SERT binding sites decreases are not a consequence of reduced SERT gene expression, as revealed by in situ hybridization measurements. SSRI-induced downregulation of the SERT may be a key component for the clinical response to SSRIs.
- Published
- 2002
- Full Text
- View/download PDF
25. Effects of chronic antidepressant treatments on serotonin transporter function, density, and mRNA level.
- Author
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Benmansour S, Cecchi M, Morilak DA, Gerhardt GA, Javors MA, Gould GG, and Frazer A
- Subjects
- Adrenergic Uptake Inhibitors pharmacology, Animals, Antidepressive Agents blood, Carrier Proteins drug effects, Desipramine pharmacology, Fluvoxamine pharmacology, Male, Membrane Glycoproteins drug effects, Monoamine Oxidase Inhibitors pharmacology, Paroxetine pharmacology, Phenelzine pharmacology, Rats, Rats, Sprague-Dawley, Serotonin pharmacokinetics, Serotonin Plasma Membrane Transport Proteins, Selective Serotonin Reuptake Inhibitors pharmacology, Sertraline pharmacology, Time Factors, Antidepressive Agents pharmacology, Carrier Proteins genetics, Carrier Proteins metabolism, Membrane Glycoproteins genetics, Membrane Glycoproteins metabolism, Membrane Transport Proteins, Nerve Tissue Proteins, RNA, Messenger metabolism
- Abstract
To investigate functional changes in the brain serotonin transporter (SERT) after chronic antidepressant treatment, several techniques were used to assess SERT activity, density, or its mRNA content. Rats were treated by osmotic minipump for 21 d with the selective serotonin reuptake inhibitors (SSRIs) paroxetine or sertraline, the selective norepinephrine reuptake inhibitor desipramine (DMI), or the monoamine oxidase inhibitor phenelzine. High-speed in vivo electrochemical recordings were used to assess the ability of the SSRI fluvoxamine to modulate the clearance of locally applied serotonin in the CA3 region of hippocampus in drug- or vehicle-treated rats. Fluvoxamine decreased the clearance of serotonin in rats treated with vehicle, DMI, or phenelzine but had no effect on the clearance of serotonin in SSRI-treated rats. SERT density in the CA3 region of the hippocampus of the same rats, assessed by quantitative autoradiography with tritiated cyanoimipramine ([(3)H]CN-IMI), was decreased by 80-90% in SSRI-treated rats but not in those treated with phenelzine or DMI. The serotonin content of the hippocampus was unaffected by paroxetine or sertraline treatment, ruling out neurotoxicity as a possible explanation for the SSRI-induced decrease in SERT binding and alteration in 5-HT clearance. Levels of mRNA for the SERT in the raphe nucleus were also unaltered by chronic paroxetine treatment. Based on these results, it appears that the SERT is downregulated by chronic administration of SSRIs but not other types of antidepressants; furthermore, the downregulation is not caused by decreases in SERT gene expression.
- Published
- 1999
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