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Impact of Annealing Treatment on the Behaviour of Titanium Dioxide Nanotube Layers

Journal of Biomaterials and Nanobiotechnology 2016年第3期7卷 142-153页

作者： Marie Siampiringue Christophe Massard Eric Caudron yves sibaud Mohammed Sarakha Komla Oscar Awitor Clermont Université Université d’Auvergne Clermont-Ferrand France Clermont Université Université Blaise Pascal Institut de Chimie de Clermont-Ferrand Clermont-Ferrand France Centre National de la Recherche Scientifique Unité Mixte de Recherches 6296 Institut de Chimie de Clermont-Ferrand Aubiere France

In this work, we study the influence of the annealing treatment on the behaviour of titanium dioxide nanotube layers. The heat treatment protocol is actually the key parameter to induce stable oxide layers and needs to be better understood. Nanotube layers were prepared by electrochemical anodization of Ti foil in 0.4 wt% hydrofluoric acid solution during 20 minutes and then annealed in air atmosphere. In-situ X-ray diffraction analysis, coupled with thermogravimetry, gives us an inside on the oxidation behaviour of titanium dioxide nanotube layers compared to bulk reference samples. Structural studies were performed at 700°C for 12 h in order to follow the time consequences on the oxidation of the material, in sufficient stability conditions. In-situ XRD brought to light that the amorphous oxide layer induced by anodization is responsible for the simultaneous growths of anatase and rutile phase during the first 30 minutes of annealing while the bulk sample oxidation leads to the nucleation of a small amount of anatase TiO2. The initial amorphous oxide layer created by anodization is also responsible for the delay in crystallization compared to the bulk sample. Thermogravimetric analysis exhibits parabolic shape of the mass gain for both anodized and bulk sample;this kinetics is caused by the formation of a rutile external protective layer, as depicted by the associated in-situ XRD diffractograms. We recorded that titanium dioxide nanotube layers exhibit a lower mean mass gain than the bulk, because of the presence of an initial amorphous oxide layer on anodized samples. In-situ XRD results also provide accurate information concerning the sub-layers behavior during the annealing treatment for the bulk and nanostructured layer. Anatase crystallites are mainly localized at the interface oxide layer-metal and the rutile is at the external interface. Sample surface topography was characterized using scanning electron microscopy (SEM). As a probe of the photoa

关键词： Titanium Dioxide Nanotubes In-Situ X-Ray Diffraction Annealing Treatment Photo-Degradation

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Boosted Photoactivity of Titania Nanotube Layers Doped with a Suspension of Gold Nanoparticles

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Advances in Nanoparticles 2017年第3期6卷 114-127页

作者： Christophe Massard Sébastien Pairis yves sibaud Christelle Blavignac Oscar Komla Awitor Université Clermont Auvergne CNRS/IN2P3 LPC+ F-63000 Clermont-Ferrand France Université Grenoble Alpes Institut NEEL CNRS BP 166 F-38042 Grenoble France Université Clermont Auvergne CICS F-63000 Clermont-Ferrand France

In the present work, we report on the behavior of synthesized gold nano-particles suspension, incorporated in titanium dioxide nanotube layers (TiO2- NT) and fabricated by electrochemical anodization in 0.4 wt% hydrofluoric acid solution and we study its photocatalytic response. Gold nanoparticles were characterized using Transmission electron microscopy and X-ray diffraction. Scanning electron microscopy was used to study the morphology of TiO2 nanotube layers doped by gold nanoparticles. Boosted photocatalytic performances on the degradation of an azo dye were obtained by using TiO2 nanotube layers doped by gold nanoparticles (Au/TiO2-NT), compared to undoped TiO2 nanotube layer (TiO2-NT) catalysts. Under UV irradiation, this new nanomaterial, with noble metal-semi conductor heterojunction (Au/ TiO2-NT) exhibits a synergetic effect in accelerating the electron transfert, resulting in an enhanced photoactivity recorded in the kinetics of degradation of Acid Orange 7 (AO7). Chronoamperometry was used to highlight higher photocurrent produced by gold-titania interface submited to UV irradiation.

关键词： Gold Nanoparticle TiO2-NT Photocurrent Photodegradation

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Photokilling of Escherichia coli Using Hybrid Titania Nanoparticles Suspended in an Aqueous Liquid

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Journal of Biomaterials and Nanobiotechnology 2013年第2期4卷 137-144页

作者： Christophe Massard Muriel Bonnet Philippe Veisseire yves sibaud Eric Caudron Komla Oscar Awitor Clermont Université Université d’Auvergne C-BIOSENSS EA-4676 Clermont-Ferrand France Clermont Université Université d’Auvergne Laboratoire de Biologie IUT Génie Biologique Aurillac France

In this work, the photokilling of Escherichia coli using a “one-pot” synthesized suspension of anatase crystallized nanoparticles is evaluated. Preliminary to the biological tests concerning the antibacterial efficiency, the fabricated suspension, using a derived solgel process in soft chemistry condition, is characterized. Structural properties of the nanoparticles are investigated using Electronic Transmission Microscopy (TEM) equipped with Selected Area Electron Diffraction (SAED) probe and X-ray diffraction. The inorganic solid content was evaluated by Thermogravimetric Analysis (TGA). Photodegradation of Acid Orange 7 in aqueous solution was used a probe to assess the photocatalytic activity of the elaborated suspension under UV irradiation. The photokilling of Escherichia coli in presence of hybrid TiO2 nanoparticles suspended in aqueous liquid under UV irradiation is evaluated. Such TiO2 nanoparticles suspension shows a strong bactericidal activity with the total destruction of bacteria after only one hour.

关键词： Anatase TiO2 Photocatalysis Sol-Gel Bacteria Photokilling Escherichia coli

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Cytotoxicity Study of Gold Nanoparticles on the Basal-Like Triple-Negative HCC-1937 Breast Cancer Cell Line

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Journal of Biomaterials and Nanobiotechnology 2018年第1期9卷 13-25页

作者： Christophe Massard Clémence Dubois Vincent Raspal Pierre Daumar yves sibaud Emmanuelle Mounetou Mahchid Bamdad Oscar Komla Awitor Université Clermont Auvergne Institut Universitaire de Technologie UMR 6533 CNRS/IN2P3 LPC+ Equipe Physico Chimie des Surfaces Nanostructurées Clermont-Ferrand France Université Clermont Auvergne Institut Universitaire de Technologie UMR INSERM 1240 Imagerie Moléculaire et Stratégies Théranostiques Groupe “Résistance” Clermont-Ferrand France

The Triple Negative “Basal-like” breast cancer (TNBL) tumours have a high proliferative capacity and develop a resistance phenotype associated with metastases. However, the management of TNBL carcinomas is still not standardized. Among the promising trails, gold nanoparticles could be a relevant tool for the development of a targeted treatment for this breast cancer subtype in monotherapy, associated and/or conjugated with other drugs. In this work, we report the cytotoxicity impact of gold nanoparticles wrapped in Poly-Ethylene Glycol (PEG) on the TNBL HCC-1937 breast cancer cell line. PEG-coated gold nanoparticles (PEG-Au NPs) were synthesized by a two-step method using a reduction process followed by a post-functionalization called PEGylation. PEG-Au NPs were characterized using transmission electron microscopy and X-ray diffraction. The gold content of the samples was determined using atomic absorption spectrometer. The cytotoxicity tests were performed using Sulforhodamine B survival test and resazurin viability test. PEG-Au NPs impact analysis on HCC1937 TNBL cell line showed a clear toxic action of type dose dependent and at long term. These PEGylated gold nanoparticles present a promising tool for the development of tumor-specific radiosensitizing vectors, with or without the association of other treatment strategies.

关键词： Breast Cancer “Basal-Like” Triple Negative HCC-1937 Gold Nanoparticles Cytotoxicity

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Feasibility of a Chronic Foreign Body Infection Model Studying the Influence of TiO₂ Nanotube Layers on Bacterial Contamination

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Journal of Biomaterials and Nanobiotechnology 2016年第1期7卷 45-54页

作者： Charles Vorilhon Christophe Massard Vincent Raspal yves sibaud Christiane Forestier Nicolas Charbonnel Stéphane Descamps Komla Oscar Awitor Department of Cardiology Clermont-Ferrand University Hospital Clermont-Ferrand France C-BIOSENSS Laboratory EA 4676 Clermont-Ferrand University Clermont-Ferrand France Laboratory Microorganism UMR 6023 Clermont-Ferrand University Clermont-Ferrand France Department of Orthopedic Surgery Clermont-Ferrand University Hospital Clermont-Ferrand France

Bacterial infections on the surface of medical devices are a significant problem in therapeutic approach, especially when implants are used in the living. In cardiology, pacemaker generator pocket surfaces, made in titanium alloy can be colonized by pathogen microorganism. This contamination represents a major risk of sepsis, endocarditis and localized infections for patients. A way to limit this bacterial contamination is to modify the surface topography using nano-structuration process of the titanium alloy surface of the implanted devices. The aim of this study is to evaluate the influence of TiO2 nanotube layers on bacterial infection in the living, considering the feasibility of an animal model of chronic foreign body infection. TiO2 nanotube layers prepared by electrochemical anodization of Ti foil in 0.4 wt% hydrofluoric acid solution were implanted subcutaneously in Wistar rats. Three weeks after implantation, TiO2 implants were contaminated by a Staphylococcus epidermilis strain using two different concentrations at 106 and 108 colony forming unit (CFU) in order to induce a sufficient infection level and to avoid unwanted over infection consequences on rats health during the experiments. After 28 days in the living, 75% of nanotube layers initially submitted to the 108 CFU inoculum were contaminated while only 25% nanotube layers initially submitted to the 106 CFU inoculum remained infected. This significant result underlines the influence of TiO2 nanotube layers in decreasing the infection level. Our in vitro experiments showed that the synthesized TiO2 nanotubes indeed decreased the Staphylococcus epidermilis adhesion compared to unanodized Ti foil.

关键词： Titanium Implants Titanium Dioxide Nanotubes Bacterial Adhesion Cardiac Device Implantable

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One-pot Synthesis of TiO2 Nanoparticles in Suspensions for Quantification of Titanium Debris Release in Biological Liquids

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Advances in Nanoparticles 2012年第3期1卷 86-94页

作者： Christophe Massard Daniel Bourdeaux Vincent Raspal Emmanuelle Feschet-Chassot yves sibaud Eric Caudron Thierry Devers Kolma Oscar Awitor C-BIOSENSS Clermont Université Université d’Auvergne Clermont Ferrand France CRMD CNRS Université d’Orléans Chartres France

In this work we have developed an analytical method to measure potential titanium debris released from TiO2 nanotube layers devices immersed in biological fluids. This quantitative study is highly required to ensure both the security and non toxicity of the nanostructured surfaces used as future implantable medical devices in the living. A one-pot synthesis process is developed to produce high quality standard solutions of titanium dioxide nanoparticles in aqueous medium. The elaborated dispersion is then used to fabricate standard solutions in both aqueous and human blood plasma media. The synthesized nanoparticles dispersion was characterized by granulometry. The nanoparticles structure and morphology were then observed using Transmission Electron Microscopy (TEM). Thermogravimetric Analysis (TGA) was used to evaluate the concentration of TiO2 in the suspension. A quantitative routine by the use of Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) is developed. The quantification threshold of titanium species is found to be in the 30 - 40 ppb range. None interference is detected between the particles and the human blood plasma. Using the established quantitative routine, the titanium species release from titania nanotube layers in human blood plasma is evaluated.

关键词： Titanium Dioxide Nanotube Layer TiO2 Nanoparticles Debris Release Biological Matrix Inductively Coupled Plasma Atomic Emission Spectroscopy

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Morphometric Differentiation between Four Strains of Japanese Quail (Coturnix coturnix japonica) Reared in Southern Côte d’Ivoire

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Open Journal of Animal Sciences 2025年第1期15卷 77-88页

作者： Brahima Soro Isidore Kouadio Kpandji Sylvain Zadi Bopo Stéphane yves Aka André N’guessan Yao Didier Paulin Sokouri Laboratory of Biotechnology Agriculture and Valorisation of Biological Resources UFR Biosciences Flix Houphout-Boigny University Abidjan Cte dIvoire

The Japanese quail (Coturnix japonica) is a disease-resistant, high-productivity bird. It has few breeding constraints. A phenotypic characterization study of the Japanese quail was carried out in southern Côte d’Ivoire to gain a better understanding of this bird. The study involved 298 individuals. The phenotypes were white, black, gray, and red. A total of 11 morphometric parameters were examined. Variables were significantly different between the phenotype and sex groups. The female quail was larger than the male quail. The quail was 20.77 and 4.10 cm long. The head was supported by a 5.89 cm-long neck. The tail was 3.61 cm long. The wing length was 10.42 cm, and the thigh diameter was 2.12 cm. The tarsus was 3.39 cm long and 0.61 cm in diameter. The average quail weight was 297.06 g. The quails in this study exhibit a high degree of morphological variation between individuals in terms of plumage. These results can help develop strategies for developing and genetically improving this short-cycle resource.

关键词： Quail Coturnix japonica Phenotypic Characterization Improving

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Plasma transthyretin is a nutritional biomarker in human morbidities

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Frontiers of Medicine 2022年第4期16卷 540-550页

作者： yves Ingenbleek Faculty of Pharmacy Laboratory of NutritionUniversity of StrasbourgRoute du RhinIllkirch–Graffenstaden F-67401(Strasbourg)France

Transthyretin(TTR)is a small liver-secreted plasma protein that shows close correlations with changes in lean body mass(LBM)during the entire human lifespan and agglomerates the bulk of nitrogen(N)-containing substrates,hence constituting the cornerstone of body *** acids(AAs)dietary restriction causes inhibition of TTR production and impairs the accretion of LBM *** disorders result in cytokine-induced abrogation of TTR synthesis and urinary leakage of nitrogenous *** together,the data indicate that malnutrition and inflammation may similarly suppress the production of TTR through distinct and unrelated pathophysiological mechanisms while operating in concert to downsize LBM *** hepatic synthesis of TTR integrates both machineries,acting as a marker of reduced LBM resources still available for defense and repair *** operates as a universal surrogate analyte that allows for the grading of residual LBM capacity to reflect disease *** of TTR is a simple,rapid,and inexpensive micromethod that may be reproduced on a daily basis,hence ideally suited for the follow-up of the most intricated clinical situations and as a reliable predictor of any morbidity outcome.

关键词： lean body mass nutritional status transthyretin malnutrition inflammation amyloidosis

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Overall Thermodynamic Model of an Ultra Micro Turbine

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Journal of Thermal Science 2004年第4期13卷 297-301页

作者： yves RIBAUD ONERA DEFA 29 Avenue de la Division Leclerc 92 CHATILLON France

The overall thermodynamic model of an ultra micro turbine engine has been established and applied in different situations in this tiny engine where heat transfer is dominant. The aerothermal conditions of the flow were calculated and analyzed. A corresponding calculation software (hot button software) was developed. The first results show that the non-adiabatic operation of the turbomachines leads to a strong penalty in performances. The dramatic influence of the compressor and turbine efficiency is confirmed in a non-adiabatic operation. A better knowledge of heat transfer coefficients at low Reynolds numbers in different components of the micro turbine has to be obtained to refine the results of this study.

关键词： micro energy micro engines micro turbine micro propulsion micro turbine thermodynamic model MEMS

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Three Problems on Trigonometric Sums

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Acta Mathematica Sinica,English Series 2019年第6期35卷 721-727页

作者： yves MEYER CMLA ENS Paris-Saclay

Let Λ ? R^n be a uniformly discrete set and let C_Λ be the vector space consisting of all mean periodic functions whose spectrum is simple and contained in Λ. If Λ is a gentle set then for every f ∈ C_Λ we have f(x) = O(ω_Λ(x)) as |x| →∞ and ω_Λ(x) can be estimated(Theorem 4.1). This line of research was proposed by Jean-Pierre Kahane in 1957.

关键词： Mean periodic functions almost periodic functions trigonometric sums

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