المؤلفون: Hajar Ftouhi, Hind Lamkaouane, Mustapha Diani, Guy Louarn, Ludovic Arzel, Jean-Christian Bernède, Mohammed Addou, Linda Cattin

المصدر: Solar, Vol 2, Iss 3, Pp 375-384 (2022)

مصطلحات موضوعية: organic photovoltaic cells, ambipolar organic layer, aluminum phthalocyanine chloride, alpha-sexithiophene, Production of electric energy or power. Powerplants. Central stations, TK1001-1841

الوصف: Ternary planar heterojunction organic solar cells (PHJ-OPVs) were fabricated using three organic small molecules, alpha-sexithiophene (α-6T), aluminum phthalocyanine chloride (AlPcCl) and fullerene (C60). These molecules can be easily sublimated under a vacuum; they have complementary optical absorption spectra and their energy band structure alignment is favorable for electronic charge transfers. Moreover, α-6T and AlPcCl have almost the same HOMO, which is desirable to avoid any decrease in open circuit voltage. The AlPcCl intercalated layer bridges the energy levels of the electron donor, α-6T, and the electron acceptor, C60, which facilitates charge transport through the energy cascade effect. Moreover, the charge carrier mobility measurements of AlPcCl, using the space charge limited current method, demonstrated that it iss ambipolar. All these properties combine to improve the power conversion efficiency (PCE) of PHJ-OPVs by moving from binary structures (α-6T/C60, α-6T/AlPcCl and AlPcCl/C60) to ternary ones (α-6T/AlPcCl/C60). We show, in this study, that both interfaces of the ternary PHJ-OPVs are efficient for carrier separation. After optimization of the different layer thickness, we show that, by comparing the optimum efficiencies of the binary PHJ-OPVs, the realization of ternary PHJ-OPVs, based on the active layers α-6T/AlPcCl/C60, using the following optimized method, allows us to achieve a PCE of 4.33%.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/2673-9941/2/3/22Test; https://doaj.org/toc/2673-9941Test

الوصول الحر: https://doaj.org/article/b9ce9f5bf30d4b8c86f6c03637e8a3feTest

المؤلفون: Rebeca da Rocha Rodrigues, Diogo Silva Pellosi, Guy Louarn, Laura Oliveira Péres

المصدر: Materials, Vol 16, Iss 10, p 3663 (2023)

مصطلحات موضوعية: PEDOT, polyfluorene, plasmonic nanoparticles, Raman spectroscopy, sensors, Technology, Electrical engineering. Electronics. Nuclear engineering, TK1-9971, Engineering (General). Civil engineering (General), TA1-2040, Microscopy, QH201-278.5, Descriptive and experimental mechanics, QC120-168.85

الوصف: The use of conjugated polymers (CPs) and metallic nanoparticles is an interesting way to form nanocomposites with improved optical properties. For instance, a nanocomposite with high sensitivity can be produced. However, the hydrophobicity of CPs may hamper applications due to their low bioavailability and low operability in aqueous media. This problem can be overcome by forming thin solid films from an aqueous dispersion containing small CP nanoparticles. So, in this work we developed the formation of thin films of poly(9,9-dioctylfluorene-co-3,4-ethylenedioxythiophene) (PDOF-co-PEDOT) from its natural and nano form (NCP) from aqueous solution. These copolymers were then blended in films with triangular and spherical silver nanoparticles (AgNP) for future applicability as a SERS sensor of pesticides. TEM characterization showed that the AgNP were adsorbed on the NCP surface, forming a nanostructure with an average diameter of 90 nm (value according to that obtained by DLS) and with a negative potential zeta. These nanostructures were transferred to a solid substrate, forming thin and homogeneous films with different morphology of PDOF-co-PEDOT films, as observed by atomic force microscopy (AFM). XPS data demonstrated the presence of the AgNP in the thin films, as well as evidence that films with NCP are more resistant to the photo-oxidation process. Raman spectra showed characteristic peaks of the copolymer in the films prepared with NCP. It should also be noted the enhancement effect of Raman bands observed on films containing AgNP, a strong indication of the SERS effect induced by the metallic nanoparticles. Furthermore, the different geometry of the AgNP influences the way in which the adsorption between the NCP and the metal surface occurs, with a perpendicular adsorption between the NCP chains and the surface of the triangular AgNP.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/1996-1944/16/10/3663Test; https://doaj.org/toc/1996-1944Test

الوصول الحر: https://doaj.org/article/fd1fa0c66fe84e40bb5e5458de679112Test

المؤلفون: Linda Cattin, Guy Louarn, Ludovic Arzel, Nicolas Stephant, Mustapha Morsli, Jean Christian Bernède

المصدر: ACS Omega, Vol 6, Iss 10, Pp 6614-6622 (2021)

مصطلحات موضوعية: Chemistry, QD1-999

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2470-1343Test

الوصول الحر: https://doaj.org/article/95ccadf2be4b4220949ff0021de70bfcTest

المؤلفون: Laura Oliveira Péres, Rebeca da Rochas Rodrigues, Guy Louarn

المصدر: Molecules, Vol 27, Iss 24, p 8699 (2022)

مصطلحات موضوعية: phenylene, oligomers, X-ray, Raman, terphenyl, quaterphenyl, Organic chemistry, QD241-441

الوصف: In this study, we report on crystallographic studies that were performed on Na- and K-doped terphenyl and quaterphenyl. The data obtained via X-ray scattering and transmission electron diffraction show that, for both K-doped terphenyl and quaterphenyl samples, there is an increase in the c parameter. However, in regard to Na-doped terphenyl, there is a c parameter decrease along with an a parameter increase, which may be accounted for by the polymerization of this oligomer. Moreover, in order to complete the crystallographic study, a Raman analysis was conducted to describe the localization of the radical anions and the local distortions induced by the electric charges during the doping process.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/1420-3049/27/24/8699Test; https://doaj.org/toc/1420-3049Test

الوصول الحر: https://doaj.org/article/3a70b104b1f642f19ca1cace97c64f45Test

المؤلفون: Hind Lamkaouane, Hajar Ftouhi, Mireille Richard-Plouet, Nicolas Gautier, Nicolas Stephant, Mimoun Zazoui, Mohammed Addou, Linda Cattin, Jean Christian Bernède, Yamina Mir, Guy Louarn

المصدر: Nanomaterials, Vol 12, Iss 18, p 3171 (2022)

مصطلحات موضوعية: hybrid layer, thin films, 2D nanomaterials, transition metal dichalcogenide, molybdenum disulfide, molybdenum trioxide, Chemistry, QD1-999

الوصف: In the present study, MoO3:MoS2 hybrid thin layers have been synthesized through partial oxidation of MoS2. We have demonstrated that the reaction requires darkness conditions to decrease the oxidation rate, thus obtaining the hybrid, MoO3:MoS2. A simple liquid-phase exfoliation (LPE) is carried out to achieve homogenous MoS2 nanoflakes and high reproducibility of the results after MoS2 oxidation. XPS analyses reveal the presence of MoO3, MoS2, and MoOxSy in the hybrid layer. These results are also confirmed by X-ray diffraction and high-resolution TEM. Optical absorbance reveals that the absorption peaks of the MoO3:MoS2 hybrid are slightly redshifted with the appearance of absorption peaks in the near-infrared region due to the defects created after the oxidation reaction. The composition and atomic percentages of each component in the hybrid layer as a function of reaction time have also been reported to give perspective guides for improving electronic and optoelectronic devices based on 2D-MoS2.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/2079-4991/12/18/3171Test; https://doaj.org/toc/2079-4991Test

الوصول الحر: https://doaj.org/article/208ff94e1b0f46f38641e483da117ebfTest

المؤلفون: Emilie Duchalais, Christophe Guilluy, Steven Nedellec, Melissa Touvron, Anne Bessard, Yann Touchefeu, Céline Bossard, Hélène Boudin, Guy Louarn, Michel Neunlist, Laurianne Van Landeghem

المصدر: Cellular and Molecular Gastroenterology and Hepatology, Vol 5, Iss 1, Pp 31-49 (2018)

مصطلحات موضوعية: Colorectal Cancer, Enteric Neurons, Adhesion, Migration, Diseases of the digestive system. Gastroenterology, RC799-869

الوصف: In several types of cancers, tumor cells invade adjacent tissues by migrating along the resident nerves of the tumor microenvironment. This process, called perineural invasion, typically occurs along extrinsic nerves, with Schwann cells providing physical guidance for the tumor cells. However, in the colorectal cancer microenvironment, the most abundant nervous structures belong to the nonmyelinated intrinsic enteric nervous system (ENS). In this study, we investigated whether colon cancer cells interact with the ENS. Methods: Tumor epithelial cells (TECs) from human primary colon adenocarcinomas and cell lines were cocultured with primary cultures of ENS and cultures of human ENS plexus explants. By combining confocal and atomic force microscopy, as well as video microscopy, we assessed tumor cell adhesion and migration on the ENS. We identified the adhesion proteins involved using a proteomics approach based on biotin/streptavidin interaction, and their implication was confirmed further using selective blocking antibodies. Results: TEC adhered preferentially and with stronger adhesion forces to enteric nervous structures than to mesenchymal cells. TEC adhesion to ENS involved direct interactions with enteric neurons. Enteric neuron removal from ENS cultures led to a significant decrease in tumor cell adhesion. TECs migrated significantly longer and further when adherent on ENS compared with on mesenchymal cells, and their trajectory faithfully followed ENS structures. Blocking N-cadherin and L1CAM decreased TEC migration along ENS structures. Conclusions: Our data show that the enteric neuronal network guides tumor cell migration, partly via L1CAM and N-cadherin. These results open a new avenue of research on the underlying mechanisms and consequences of perineural invasion in colorectal cancer.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S2352345X17301480Test; https://doaj.org/toc/2352-345XTest

الوصول الحر: https://doaj.org/article/c1a241bb18b04076b030fcd1822be9a5Test

المؤلفون: Linda Cattin, Guy Louarn, Mustapha Morsli, Jean Christian Bernède

المصدر: Nanomaterials, Vol 11, Iss 2, p 393 (2021)

مصطلحات موضوعية: semi-transparent organic photovoltaic cells, dielectric/metal/dielectric transparent electrode, top transparent anode, MoO3/Ag/MoO3, inverted planar heterojunction, SubPc/C60 active layers, Chemistry, QD1-999

الوصف: In order to grow semi-transparent organic photovoltaic cells (OPVs), multilayer dielectric/metal/dielectric (D/M/D) structures are used as a transparent top electrode in inverted OPVs. Two different electrodes are probed, MoO3/Ag/MoO3 and MoO3/Ag/Cu:Ag/ZnS. Both of them exhibit high transmission in visible and small sheet resistance. Semi-transparent inverted OPVs using these electrodes as the top anode are probed. The active organic layers consist in the SubPc/C60 couple. The dependence of the OPV performances on the top electrode was investigated. The results show that far better results are achieved when the top anode MoO3/Ag/MoO3 is used. The OPV efficiency obtained was only 20% smaller in comparison with the opaque OPV, but with a transparency of nearly 50% in a broad range of the visible light (400–600 nm). In the case of MoO3/Ag/Cu:Ag/ZnS top anode, the small efficiency obtained is due to the presence of some Cu diffusion in the MoO3 layer, which degrades the contact anode/organic material.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/2079-4991/11/2/393Test; https://doaj.org/toc/2079-4991Test

الوصول الحر: https://doaj.org/article/c50b0c86d984484699b1603bd890da27Test

المؤلفون: Christelle Darrieutort-Laffite, Paul Arnolfo, Thomas Garraud, Annie Adrait, Yohann Couté, Guy Louarn, Valérie Trichet, Pierre Layrolle, Benoit Le Goff, Frédéric Blanchard

المصدر: Journal of Clinical Medicine, Vol 8, Iss 10, p 1544 (2019)

مصطلحات موضوعية: calcific tendonitis, rotator cuff, apatite, hypertrophic chondrocytes, tissue non-specific alkaline phosphatase, Medicine

الوصف: Calcific tendonitis is a frequent cause of chronic shoulder pain. Its cause is currently poorly known. The objectives of this study were to better characterize the cells and mechanisms involved in depositing apatite crystals in human tendons. Histologic sections of cadaveric calcified tendons were analyzed, and human calcific deposits from patients undergoing lavage of their calcification were obtained to perform infrared spectroscopy and mass spectrometry-based proteomic characterizations. In vitro, the mineralization ability of human rotator cuff cells from osteoarthritis donors was assessed by alizarin red or Von Kossa staining. Calcifications were amorphous areas surrounded by a fibrocartilaginous metaplasia containing hypertrophic chondrocyte-like cells that expressed tissue non-specific alkaline phosphatase (TNAP) and ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1), which are two key enzymes of the mineralization process. Calcific deposits were composed of apatite crystals associated with proteins involved in bone and cartilage development and endochondral bone growth. In vitro, tenocyte-like cells extracted from the rotator cuff were able to mineralize in osteogenic cultures, and expressed TNAP, type X COLLAGEN, and MMP13, which are hypertrophic chondrocytes markers. The use of a TNAP inhibitor significantly prevented mineral deposits. We provide evidence that tenocytes have a propensity to differentiate into hypertrophic chondrocyte-like cells to produce TNAP-dependent calcium deposits. We believe that these results may pave the way to identifying regulating factors that might represent valuable targets in calcific tendonitis.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/2077-0383/8/10/1544Test; https://doaj.org/toc/2077-0383Test

الوصول الحر: https://doaj.org/article/4a09b66646784ec894c792bfb5b3e3d4Test

المؤلفون: Angélina D’Orlando, Maxime Bayle, Guy Louarn, Bernard Humbert

المصدر: Materials, Vol 12, Iss 9, p 1372 (2019)

مصطلحات موضوعية: enhanced Raman spectroscopy, plasmonic nanoparticles, AFM-nanomanipulations, optical near-field, plasmonic molecules, Technology, Electrical engineering. Electronics. Nuclear engineering, TK1-9971, Engineering (General). Civil engineering (General), TA1-2040, Microscopy, QH201-278.5, Descriptive and experimental mechanics, QC120-168.85

الوصف: This paper explores the enhancement of Raman signals using individual nano-plasmonic structures and demonstrates the possibility to obtain controlled gold plasmonic nanostructures by atomic force microscopy (AFM) manipulation under a confocal Raman device. By manipulating the gold nanoparticles (Nps) while monitoring them using a confocal microscope, it is possible to generate individual nano- structures, plasmonic molecules not accessible currently by lithography at these nanometer scales. This flexible approach allows us to tune plasmonic resonance of the nanostructures, to generate localized hot spots and to circumvent the effects of strong electric near field gradients intrinsic to Tip Enhanced Raman Spectroscopy (TERS) or Surface Enhanced Raman Spectroscopy (SERS) experiments. The inter Np distances and symmetry of the plasmonic molecules in interaction with other individual nano-objects control the resonance conditions of the assemblies and the enhancement of their Raman responses. This paper shows also how some plasmonic structures generate localized nanometric areas with high electric field magnitude without strong gradient. These last plasmonic molecules may be used as "nano-lenses" tunable in wavelength and able to enhance Raman signals of neighbored nano-object. The positioning of one individual probed nano-object in the spatial area defined by the nano-lens becomes then very non-restrictive, contrary to TERS experiments where the spacing distance between tip and sample is crucial. The experimental flexibility obtained in these approaches is illustrated here by the enhanced Raman scatterings of carbon nanotube.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/1996-1944/12/9/1372Test; https://doaj.org/toc/1996-1944Test

الوصول الحر: https://doaj.org/article/8836005f89a04f88affc4471e372345dTest

المؤلفون: Henrique de Santana, Dimas A. M. Zaia, Paola Corio, Fady El Haber, Guy Louarn

المصدر: Química Nova, Vol 29, Iss 2, Pp 194-199 (2006)

مصطلحات موضوعية: Chemistry, QD1-999

وصف الملف: electronic resource

العلاقة: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422006000200003&tlng=ptTest; http://www.scielo.br/pdf/qn/v29n2/28431.pdfTest; https://doaj.org/toc/1678-7064Test

الوصول الحر: https://doaj.org/article/5f39873a203b460d921de4209a9f0f74Test