Academic literature on the topic 'Composites tissés lin'

Исследованы структурные особенности нанокомпозитов, полученных при лазерном облучении водно-белковых сред с одностенными углеродными нанотрубками (ОУНТ), электродуговым (ОУНТI) и газофазным методами (ОУНТII). С помощью спектроскопии комбинационного рассеяния нанокомпозитов определен нековалентный характер взаимодействия нанотрубок с молекулами белков. Белковая составляющая в нанокомпозитах подверглась необратимой денатурации и может выступать в качестве связующего биосовместимого материала, который является источником аминокислот для биологических тканей при имплантации нанокомпозитов в организм. Образцы, изготовленные из ОУНТI, с меньшим диаметром и длиной имели наиболее однородную структуру. При увеличении концентрации от 0.01 до 0.1 % происходило увеличение среднего размерамикропор от 45 до 85 мкм и пористости образца в общем с 46 до 58 %. При этом доля открытых пор для двух типов концентраций ОУНТI составила 2 % от общего объема композита. В нанокомпозитах на основе ОУНТI показано наличие мезопор. Увеличение концентрации нанотрубок привело к уменьшению удельных значений поверхности и объема пор образца. Исследованные нанокомпозиты могут использоваться в качестве тканеинженерных матриц для восстановления объемных дефектов биологических тканей REFERENCES Eletskii A. V. Carbon nanotubes. Usp., 1997, v. 40(9), pp. 899–924. https://dji.org/10.1070/PU1997v040n09ABEH000282 Tuchin A. V., Tyapkina V. A., Bityutskaya L. A., Bormontov E. N. Functionalization of capped ultrashort single-walled carbon nanotube (5, 5). Condensed matter and interphases, 2016, v. 18(4), pp. 568–577. URL: http://www.kcmf.vsu.ru/resources/t_18_4_2016_015.pdf (in Russ.) Dolgikh I., Tyapkina V. A., Kovaleva T. A., Bityutskaya L. A. 3D Topological changes in enzyme glucoamylase when immobilized on ulrta0short carbon naotubes. Condensed matter and interphases, 2016, v. 18(4), pp. 505–512. URL: http://www.kcmf.vsu.ru/resources/t_18_4_2016_007.pdf (in Russ.) Kulikova T. V., Tuchin A. V., Testov D. A., Bityutskaya L. A., Bormontov E. N., Averin A. A. Structure and properties of self-organized 2D and 3D antimony/carbon composites. Technical Physics, 2018, v. 63(7), pp. 995–1001. https://doi.org/10.1134/S1063784218070216 Kulikova T. V., Bityutskaya L. A., Tuchin A. V., Lisov E. V., Nesterov S. I., Averin A. A., Agapov B. L. Structural heterogeneities and electronic effects in self-organized core-shell type structures of Sb. Letters on materials, 2017, v. 7(4), pp. 350–354. https://doi.org/10.22226/2410-3535-2017-4-350-354 Gerasimenko A. Yu. Laser structuring of the carbon nanotubes ensemble intended to form biocompatible ordered composite materials. Condensed matter and interphases, 2017, v. 19(4), pp. 489–501. https://doi.org/10.17308/kcmf.2017.19/227 Ma R. Z., Wei B. Q., Xu C. L., Liang J., Wu D. H. The morphology changes of carbon nanotubes under laser irradiation. Carbon, 2000, vol. 38(4), pp. 636–638. https://doi.org/10.1016/s0008-6223(00)00008-7 Sadeghpour H. R., Brian E. Interaction of laser light and electrons with nanotubes. Physica Scripta, 2004, vol. 110, pp. 262–267. https://doi.org/10.1238/physica. topical.110a00262 Gyorgy E., Perez del Pino A., Roqueta J., Ballesteros B., Cabana L., Tobias G. Effect of laser radiation on multi-wall carbon nanotubes: study of shell structure and immobilization process. of Nanoparticle Research, 2013, v. 15(8), p. 1852. https://doi.org/10.1007/s11051-013-1852-6 Krasheninnikov A. V., Banhart F. Engineering of nanostructured carbon materials with electron or ion beams. Nature Materials, 2007, v. 6(10), pp. 723–733. https://doi.org/10.1038/nmat1996 Ogihara N., Usui Y., Aoki K., Shimizu M., Narita N., Hara K., Nakamura K., Ishigaki N., Takanashi S., Okamoto M., Kato H., Haniu H., Ogiwara N., Nakayama N., Taruta S., Saito N. Biocompatibility and bone tissue compatibility of alumina ceramics reinforced with carbon nanotubes. Nanomedicine, 2012, v. 7(7), pp. 981–993. https://doi.org/10.2217/nnm.12.1 Abarrategi A., Gutiérrez M.C., Moreno-Vicente C., Hortigüela M. J., Ramos V., Lуpez-Lacomba J. L., Ferrer M. L., del Monte F. Multiwall carbon nanotube scaffolds for tissue engineering purposes. Biomaterials, 2008, v. 29(1), pp. 94–102. https://doi.org/10.1016/j.biomaterials.2007.09.021 Newman P., Minett A., Ellis-Behnke R., Zreiqat H. Carbon nanotubes: Their potential and pitfalls for bone tissue regeneration and engineering. Nanomedicine, 2013, v. 9(8), pp. 1139–1158. https://doi.org/10.1016/j.nano.2013.06.001 Sahithi K., Swetha M., Ramasamy K., Selvamurugan N. Polymeric composites containing carbon nanotubes for bone tissue engineering. International journal of biological macromolecules, 2010, v. 46(3). pp. 281–283. https://doi.org/10.1016/j.ijbiomac.2010.01.006 Pan L., Pei, He R., Wan Q., Wang J. Colloids and Surfaces B: Biointerfaces, 2012, vol. 93, pp. 226–234. https://doi.org/10.1016/j.colsurfb.2012.01.011 Mattioli-Belmonte M., Vozzi G, Whulanza Y., Seggiani M., Fantauzzi V., Orsini G., Ahluwalia A. Tuning polycaprolactone–carbon nanotube composites for bone tissue engineering scaffolds. Materials Science and Engineering: C, 2012, v. 32(2), pp. 152–159. https://doi.org/10.1016/j.msec.2011.10.010 Venkatesan J., Qian Z., Ryu B., Kumar N.A., Kim S. Preparation and characterization of carbon nanotube-grafted-chitosan – Natural hydroxyapatite composite for bone tissue engineering. Carbohydrate Polymers, 2011, v. 83(2). pp. 569–577. https://doi.org/10.1016/j.carbpol.2010.08.019 Lin C., Wang Y., Lai Y., Yang W., Jiao F., Zhang H., Shefang Ye., Zhang Q. Incorporation of carboxylation multiwalled carbon nanotubes into biodegradable poly(lactic-co-glycolic acid) for bone tissue engineering. Colloids and Surfaces B: Biointerfaces, 2011, v. 83(2), pp. 367–375. https://doi.org/10.1016/j.colsurfb.2010.12.011 Gerasimenko A. Yu. , Glukhova O. E., Savostyanov G. V., Podgaetsky V. M. Laser structuring of carbon nanotubes in the albumin matrix for the creation of composite biostructures. Journal of Biomedical Optics, 2017, v. 22(6), pp. 065003-1–065003-8. https://doi.org/10.1117/1.jbo.22.6.065003

Trauma pada gigi yang dialami pada saat muda dapat menyebabkan gigi immature non vital dengan apek terbuka, yang berlanjut pada infeksi pada jaringan pulpa dan diskolorasi gigi. Laporan kasus ini menyajikan penggunaan MTA (Mineral Trioxide Aggregate) sebagai bahan apeksifikasi, perawatan bleaching intrakoronal serta restorasi resin komposit dengan pasak resin komposit aktivasi kimia pada gigi insisivus sentralis kanan maksila, sehingga dapat mempertahankan dan mengembalikan fungsi gigi. Seorang pasien wanita muda datang ke RSGM Prof. Soedomo untuk merawatkan gigi insisivus sentralis kanan maksila yang patah 11 tahun yang lalu karena jatuh. Diagnosa gigi insisivus sentralis kanan maksila fraktur Kelas IV Ellis, pulpa nekrosis dengan lesi periapikal, apeks terbuka, dan diskolorasi. Prosedur perawatan diawali dengan preparasi saluran akar teknik konvensional, apeksifikasi menggunakan MTA dan bleaching intrakoronal teknik walking bleach, restorasi resin komposit kavitas kelas IV dengan teknik mock up dan pasak resin komposit. Apeksifikasi dan bleaching intra koronal disertai pasak dan restorasi resin komposit adalah perawatan yang baik yang dapat dilakukan pada gigi insisivus sentralis kanan maksila imature, dengan pulpa terbuka dan diskolorasi. Pasien merasa puas dengan perawatan yang telah dilakukan dan fungsi gigi juga telah dapat dikembalikan, antara lain fungsi estetik dan fonetik. ABSTRACT: Apexification Using Mineral Trioxide Aggregate, Intracoronal Bleaching, and Composite Resin Restoration with Dental Composite Resin Posts Right Central Maxillary. Trauma to teeth in a young age can cause non vital immature teeth with open apex, which leads to the infection in the pulp tissue and discoloration of the teeth. This case report is to present the use of MTA (Mineral Trioxide Aggregate) as apexification material, intracoronal bleaching treatments and composite resin restorations with composite resin chemical activation posts on the maxillary right central incisor, so as to maintain and restore tooth function. A young female patient came to Prof. Soedomo Dental Hospital to repair right maxillary central incisors which were broken 11 years previously because of falling. The diagnosis was right maxillary central incisor Ellis Class III fractures, pulp necrosis with periapical lesions, open apex, and discoloration. The treatment procedure began with the conventional root canal preparation techniques, apexification using Mineral Trioxide Aggregate (MTA) and intracoronal bleaching with the technique of walking bleach. The composite resin restorations class IV cavities used a mock-up technique and composite resin post. Apexification and intra-coronal bleaching with post and composite resin restorations are good treatments that can be performed on the immature right maxillary central incisor, without exposing pulp and discoloration. The patient was satisfied with the care that had been done and also; the function of her teeth could be restored, including aesthetic and phonetic functions.

Background Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin's lymphoma (NHL) in adults. R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone) remains the standard of care for newly diagnosed DLBCL, with cure rates of 60-70%. However, more effective front-line options are needed to further improve outcomes, particularly in high-risk patients (Sehn LH, Gascoyne RD. Blood 2015;125:22). Approximately 15-20% of treatment-naïve patients with DLBCL have CD20-low expressing tumors, while CD19 is expressed in >90% of DLBCL. CD20-low DLBCL is associated with poor response to rituximab-based regimens (Johnson NA, et al. Blood 2009;113:3773; Prevodnik VK, et al. Diagnostic Pathol 2011;6:33). CD19 is a B-lymphocyte lineage-specific surface antigen that is widely expressed in mature B-cell malignancies, including DLBCL. CD19 functions as a positive regulator of B-cell receptor signaling and is important for B-cell activation and proliferation, and is, therefore, an attractive therapeutic target in addition to CD20. Tafasitamab (MOR208) is a humanized anti-CD19 monoclonal antibody with an engineered constant region (Fc) that enhances Fc-γ receptor binding affinity on effector cells, thereby enhancing antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis (ADCP). Preliminary data in DLBCL cell lines suggest that combined targeting of CD19 and CD20 with tafasitamab and rituximab, respectively, could have synergistic cytotoxic effects. Monotherapy with tafasitamab has shown clinical activity and acceptable safety in a Phase I study in relapsed/refractory (R/R) chronic lymphocytic leukemia/small lymphocytic lymphoma (NCT01161511) and in a Phase IIa study in R/R NHL (NCT01685008). In patients with R/R DLBCL, treatment with single agent tafasitamab until progression led to a 26% objective response rate (ORR) with several long-term responses (Jurczak W, et al. Ann Oncol 2018; 29:1266). Preclinical in vitro and in vivo data have demonstrated increased combinatorial antitumor effects with tafasitamab and the immunomodulatory agent lenalidomide (LEN). In the Phase II, single-arm L-MIND study (NCT02399085) in patients with R/R DLBCL, treatment with tafasitamab/LEN achieved an ORR of 60%, a complete response (CR) rate of 42.5% and a median progression-free survival (PFS) of 12.1 months (Salles GA, et al. ICML 2019; Abstr 124). This combination received breakthrough therapy designation by the US Food and Drug Administration. Study design and methods First-MIND is a Phase Ib, open-label, multicenter, randomized trial of tafasitamab/R-CHOP or tafasitamab/LEN/R-CHOP in patients with newly diagnosed DLBCL (Figure 1). Patients must be aged ≥18 years, treatment naïve, with histologically confirmed DLBCL not otherwise specified and have intermediate- to high-risk disease (International Prognostic Index 2-5). Key exclusion criteria include known double- or triple-hit lymphoma, and transformed or composite lymphoma. Treatment consists of six 21-day cycles of tafasitamab (12 mg/kg intravenously [IV], on Days [D] 1, 8 and 15) in addition to R-CHOP (Arm A) or tafasitamab (12 mg/kg IV, on D1, 8 and 15) and LEN (25 mg orally, on D1-10) in addition to R-CHOP (Arm B). The trial includes a safety run-in phase and a main phase. In the safety run-in phase, 12 patients will be enrolled in each arm. If no unexpected safety signals suspected to be related to the addition of tafasitamab ± LEN to R-CHOP are observed, an additional 18 patients will be enrolled in each arm in the main phase. The primary objective of the trial is to assess safety; secondary objectives include evaluation of efficacy (ORR and PET-assessed CR rate at end of treatment, PFS, overall survival, event-free survival, time to next anti-lymphoma treatment), long-term safety and pharmacokinetics, and immunogenicity of tafasitamab in each arm. Exploratory objectives will include the assessment of biomarkers in peripheral blood (natural killer [NK] cell count, cell-free circulating tumor DNA) and tumor tissue (DLBCL cell of origin, NK cell or macrophage count/gene expression profile, CD19 and CD20 expression) that may be relevant to the mechanism of action and/or response to study treatment. As this is a Phase Ib study to primarily explore safety, no formal statistical hypothesis is considered for the sample size calculation; approximately 60 patients will be recruited across Europe and the US. Disclosures Burke: Gilead: Consultancy; Roche/Genentech: Consultancy; Celgene: Consultancy. André:Celgene: Other: Travel grants, Research Funding; Chugai: Research Funding; Takeda Millenium: Research Funding; Johnson & Johnson: Research Funding; Amgen: Other: Travel grants, Research Funding; Roche: Other: Travel grants, Research Funding; Abbvie: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers-Squibb: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees, Other: Travel grants. Cheson:Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Research Funding; Acerta: Consultancy, Research Funding; Kite: Research Funding; Epizyme: Research Funding; Morphosys: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Symbios: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Trillium: Research Funding; TG Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Research Funding; Bristol Myers Squibb: Research Funding; Portola: Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Duell:Regeneron Pharmaceuticals, Inc.: Research Funding. Nowakowski:Genentech, Inc.: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Selvita: Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding; MorphoSys: Consultancy, Research Funding; Curis: Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Research Funding. Rosenwald:MorphoSys: Consultancy. Salles:Roche, Janssen, Gilead, Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; BMS: Honoraria; Novartis, Servier, AbbVie, Karyopharm, Kite, MorphoSys: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Autolus: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Epizyme: Consultancy, Honoraria; Amgen: Honoraria, Other: Educational events; Merck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Sharman:Acerta: Consultancy, Honoraria, Research Funding; TG Therapeutics: Consultancy, Honoraria, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Genentech: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Research Funding. Staber:Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Takeda-Millenium: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Honoraria, Speakers Bureau; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Trněný:Abbvie: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Gilead Sciences: Consultancy, Honoraria; Incyte: Consultancy, Honoraria; MorphoSys: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; F. Hoffmann-La Roche: Consultancy, Honoraria; Celgene: Consultancy; Janssen: Consultancy, Honoraria. Westin:Novartis: Other: Advisory Board, Research Funding; Juno: Other: Advisory Board; Unum: Research Funding; Curis: Other: Advisory Board, Research Funding; Genentech: Other: Advisory Board, Research Funding; Kite: Other: Advisory Board, Research Funding; Celgene: Other: Advisory Board, Research Funding; 47 Inc: Research Funding; MorphoSys: Other: Advisory Board; Janssen: Other: Advisory Board, Research Funding. Brugger:MorphoSys: Employment; AstraZeneca: Equity Ownership. Fingerle-Rowson:MorphoSys AG: Employment. Klanova:MorphoSys AG: Employment. Würth:MorphoSys AG: Employment. Truemper:Janssen Oncology: Consultancy; Nordic Nanovector: Consultancy; Takeda: Consultancy, Research Funding; Seattle Genetics, Inc.: Research Funding; Roche: Research Funding; Mundipharma: Research Funding.

Graphene-based composites have received a great deal of attention in recent year because the presence of graphene can enhance the conductivity, strength of bulk materials and help create composites with superior qualities. Moreover, the incorporation of metal oxide nanoparticles such as Fe3O4 can improve the catalytic efficiency of composite material. In this work, we have synthesized a composite material with the combination of reduced graphene oxide (rGO), and Fe3O4 modified tissue-paper (mGO-PP) via a simple hydrothermal method, which improved the removal efficiency of the of methylene blue (MB) in water. MB blue is used as the model of contaminant to evaluate the catalytic efficiency of synthesized material by using a Fenton-like reaction. The obtained materials were characterized by SEM, XRD. The removal of materials with methylene blue is investigated by UV-VIS spectroscopy, and the result shows that mGO-PP composite is the potential composite for the color removed which has the removal efficiency reaching 65% in acetate buffer pH = 3 with the optimal time is 7 h. Keywords Graphene-based composite, methylene blue, Fenton-like reaction. References [1] Ma Joshi, Rue Bansal, Reng Purwar, Colour removal from textile effluents, Indian Journal of Fibre & Textile Research, 29 (2004) 239-259 http://nopr.niscair.res.in/handle/123456789/24631.[2] Kannan Nagar, Sundaram Mariappan, Kinetics and mechanism of removal of methylene blue by adsorption on various carbons-a comparative study, Dyes and pigments, 51 (2001) 25-40 https://doi.org/10.1016/S0143-7208(01)00056-0.[3] K Rastogi, J. N Sahu, B. C Meikap, M. N Biswas, Removal of methylene blue from wastewater using fly ash as an adsorbent by hydrocyclone, Journal of hazardous materials, 158 (2008) 531-540.https://doi.org/10.1016/j.jhazmat.2008.01. 105.[4] Qin Qingdong, Ma Jun, Liu Ke, Adsorption of anionic dyes on ammonium-functionalized MCM-41, Journal of Hazardous Materials, 162 (2009) 133-139 https://doi.org/10.1016/j.jhazmat. 2008.05.016.[5] Mui Muruganandham, Rps Suri, Sh Jafari, Mao Sillanpää, Lee Gang-Juan, Jaj Wu, Muo Swaminathan, Recent developments in homogeneous advanced oxidation processes for water and wastewater treatment, International Journal of Photoenergy, 2014 (2014). http://dx. doi.org/10.1155/2014/821674.[6] Herney Ramirez, Vicente Miguel , Madeira Luis Heterogeneous photo-Fenton oxidation with pillared clay-based catalysts for wastewater treatment: a review, Applied Catalysis B: Environmental, 98 (2010) 10-26 https://doi.org/ 10.1016/j.apcatb.2010.05.004.[7] Guo Rong, Jiao Tifeng, Li Ruifei, Chen Yan, Guo Wanchun, Zhang Lexin, Zhou Jingxin, Zhang Qingrui, Peng Qiuming, Sandwiched Fe3O4/carboxylate graphene oxide nanostructures constructed by layer-by-layer assembly for highly efficient and magnetically recyclable dye removal, ACS Sustainable Chemistry & Engineering, 6 (2017) 1279-1288 https://doi.org/10.1021/acssuschemeng.7b03635.[8] Sun Chao, Yang Sheng-Tao, Gao Zhenjie, Yang Shengnan, Yilihamu Ailimire, Ma Qiang, Zhao Ru-Song, Xue Fumin, Fe3O4/TiO2/reduced graphene oxide composites as highly efficient Fenton-like catalyst for the decoloration of methylene blue, Materials Chemistry and Physics, 223 (2019) 751-757 https://doi.org/ 10.1016/j.matchemphys.2018.11.056.[9] Guo Hui, Ma Xinfeng, Wang Chubei, Zhou Jianwei, Huang Jianxin, Wang Zijin, Sulfhydryl-Functionalized Reduced Graphene Oxide and Adsorption of Methylene Blue, Environmental Engineering Science, 36 (2019) 81-89 https://doi. org/10.1089/ees.2018.0157.[10] Zhao Lianqin, Yang Sheng-Tao, Feng Shicheng, Ma Qiang, Peng Xiaoling, Wu Deyi, Preparation and application of carboxylated graphene oxide sponge in dye removal, International journal of environmental research and public health, 14 (2017) 1301 https://doi.org/10.3390/ijerph14111301.[11] Yu Dandan, Wang Hua, Yang Jie, Niu Zhiqiang, Lu Huiting, Yang Yun, Cheng Liwei, Guo Lin, Dye wastewater cleanup by graphene composite paper for tailorable supercapacitors, ACS applied materials & interfaces, 9 (2017) 21298-21306 https://doi.org/10.1021/acsami.7b05318.[12] Wang Hou, Yuan Xingzhong, Wu Yan, Huang Huajun, Peng Xin, Zeng Guangming, Zhong Hua, Liang Jie, Ren MiaoMiao, Graphene-based materials: fabrication, characterization and application for the decontamination of wastewater and wastegas and hydrogen storage/generation, Advances in Colloid and Interface Science, 195 (2013) 19-40 https://doi. org/10.1016/j.cis.2013.03.009.[13] Marcano Daniela C, Kosynkin Dmitry V, Berlin Jacob M, Sinitskii Alexander, Sun Zhengzong, Slesarev Alexander, Alemany Lawrence B, Lu Wei, Tour James M, Improved synthesis of graphene oxide, ACS nano, 4 (2010) 4806-4814 https://doi.org/10.1021/nn1006368.[14] Zhang Jiali, Yang Haijun, Shen Guangxia, Cheng Ping, Zhang Jingyan, Guo Shouwu, Reduction of graphene oxide via L-ascorbic acid, Chemical Communications, 46 (2010) 1112-1114 http://doi. org/10.1039/B917705A [15] Gong Ming, Zhou Wu, Tsai Mon-Che, Zhou Jigang, Guan Mingyun, Lin Meng-Chang, Zhang Bo, Hu Yongfeng, Wang Di-Yan, Yang Jiang, Nanoscale nickel oxide/nickel heterostructures for active hydrogen evolution electrocatalysis, Nature communications, 5 (2014) 4695 https:// doi.org/10.1038/ncomms5695.[16] Wu Zhong-Shuai, Yang Shubin, Sun Yi, Parvez Khaled, Feng Xinliang, Müllen Klaus, 3D nitrogen-doped graphene aerogel-supported Fe3O4 nanoparticles as efficient electrocatalysts for the oxygen reduction reaction, Journal of the American Chemical Society, 134 (2012) 9082-9085 https://doi.org/10.1021/ja3030565.[17] Nguyen Son Truong, Nguyen Hoa Tien, Rinaldi Ali, Nguyen Nam Van, Fan Zeng, Duong Hai Minh, Morphology control and thermal stability of binderless-graphene aerogels from graphite for energy storage applications, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 414 (2012) 352-358 https://doi.org/ 10.1016/j.colsurfa.2012.08.048.[18] Deng Yang, Englehardt James D, Treatment of landfill leachate by the Fenton process, Water research, 40 (2006) 3683-3694 https://doi.org/ 10.1016/j.watres.2006.08.009.

Os defeitos mandibulares devido à ressecção de lesão óssea interferem a harmonia e estética facial comprometendo a qualidade de vida dos pacientes. Grandes defeitos exigem planejamento minucioso, principalmente quando lançamos mão de enxertos e placas de reconstrução, evitando assim resultados insatisfatórios ou até mesmo sequelas. Apesar de algumas classificações dos defeitos mandibulares vêm sendo discutidas ao longo dos anos, ainda não há um protocolo definido para reconstrução mandibular. O uso de prototipagem na Cirurgia Bucomaxilofacial tem se tornado cada vez mais frequente; a precisão da reconstrução, diminuição do tempo de cirurgia reflete em recuperação mais rápida do paciente. Mesmo com a ferramenta da prototipagem, grandes lesões e perdas ósseas permanecem como grande desafio ao cirurgião. O objetivo deste trabalho é relatar um caso clínico de reconstrução mandibular no qual houve a necessidade de ser tratado com remoção de placa de reconstrução e nova reabilitação cirúrgica do paciente.Descritores: Mandíbula; Reconstrução Mandibular; Modelos Biológicos.ReferênciasSantos LCS, Seixas AM, Barbosa B, Cincura RNS. Adaptação de placas reconstrutivas: uma nova técnica. Rev Cir Traumatol Buco-Maxilo-Fac. 2011;11(2):9-14.Lin PY, Lin KC, Jeng SF. Oromandibular reconstruction: the history, operative options and strategies, and our experience. ISRN Surg. 2011;2011:824251.Martins Jr. JC, Keim FS. Uso de prototipagem no planejamento de reconstrução microcirúrgica da mandíbula. Rev Bras Cir Craniomaxilofac. 2011;14(4):225-28.Montoro JR, Tavares MG, Melo DH, Franco Rde L, Mello-Filho FV, Xavier SP, Trivellato AE, Lucas AS. Mandibular ameloblastoma treated by bone resection and imediate reconstruction. Braz J Otorhinolaryngol. 2008;74(1):155-57.Nóia CF, Ortega-Lopes R, Chaves Netto HDM, Nascimento FFAO, Sá BCM. Desafios na reconstrução mandibular devido a lesões extensas ou traumatismos. Rev Assoc Paul Cir Dent. 2015;69(2):158-63.Cohen A, Laviv A, Berman P, Nashef R, Abu-Tair J. Mandibular reconstruction using stereolithographic 3-dimensional printing modeling technology. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009;108(5):661-6.Rana M, Warraich R, Kokemüller H, Lemound J, Essig H, Tavassol F et al. Reconstruction of mandibular defects - clinical retrospective research over a 10-year period. Head Neck Oncol. 2011;3:23.Fariña R, Alister JP, Uribe F, Olate S, Arriagada A. Indications of Free Grafts in Mandibular Reconstruction, after Removing Benign Tumors: Treatment Algorithm. Plast Reconstr Surg Glob Open. 2016;4(8):e845.Fariña R, Plaza C, Martinovic G. New transference technique of position of mandibular reconstructing plates using stereolithographic models. J Oral Maxillofac Surg. 2009;7(11):2544-48.Mooren RE, Merkx MA, Kessler PA, Jansen JA, Stoelinga PJ. Reconstruction of the mandible using preshaped 2.3-mm titanium plates, autogenous cortical bone plates, particulate cancellous bone, and platelet-rich plasma: a retrospective analysis of 20 patients. J Oral Maxillofac Surg. 2010;68(10):2459–67.Brown JS, Barry C, Ho M, Shaw R.A new classification for mandibular defects after oncological resection. Lancet Oncol. 2016;17(1):23-30Urken ML, Weinberg H, Vickery C, Buchbinder D, Lawson W, Biller HF. Oromandibular reconstruction using microvascular composite free flaps. Report of 71 cases and a new classification scheme for bony, soft-tissue, and neurologic defects. Arch Otolaryngol Head Neck Surg. 1991;117(7):733-44.Shnayder Y, Lin D, Desai SC, Nussenbaum B, Sand JP, Wax MK. Reconstruction of the Lateral Mandibular Defect: A Review and Treatment Algorithm. JAMA Facial Plast Surg. 2015;17(5):367-73.Wei FC, Celik N, YangWG, Chen IH, Chang YM, Chen HC. Complications after reconstruction by plate and soft-tissue free flap in composite mandibular defects and secondary salvage reconstruction with osteocutaneous flap. Plast Reconstr Surg. 2003;112(1):37-42.Li BH, Jung HJ, Choi SW, Kim SM, Kim MJ, Lee JH. Latissimus dorsi (LD) free flap and reconstruction plate used for extensive maxillo-mandibular reconstruction after tumour ablation. J Craniomaxillofac Surg. 2012;40(8):293-300.

La caractérisation multi-échelle des préformes textiles en fibres naturelles est un moyen indispensable pour comprendre et évaluer les propriétés mécaniques et le comportement du composite. Dans cette étude, une caractérisation expérimentale multi-échelle est réalisée sur des tissus 3D interlock chaine en fibre de lin à l'échelle des fibres (micro), des mèches (méso), des tissus et des matériaux composites (macro). Les propriétés mécaniques en traction de la fibre de lin ont été déterminées en utilisant la méthodologie de l'IFBT. L'effet de la torsion a également été pris en compte dans le calcul de la rigidité de la fibre et a révélé les limites de la loi des mélanges et d'autres modèles. Des essais de traction sur des mèches sèches ont été effectués en considérant différents niveaux de torsion afin de déterminer le niveau de torsion optimal pour tisser 3D la mèche de lin. Les résultats révèlent l'importance de considérer les propriétés de la fibre et des mèches à ces échelles pour déterminer la matière première la plus adéquate pour le tissage. A l'échelle du tissu, dix sept tissus 3D interlocks chaines ont été réalisés pour comprendre l’influence des paramètres produits sur les paramètres textiles et sur le comportement mécanique. La caractérisation des structures tissées 3D interlock chaine montre le rôle prépondérant des mèches sur les propriétés structurelles et mécaniques. A l'échelle macroscopique suivante, les six structures résinées ont permis d'établir des relations entre les structures de renfort et les matériaux composites associés. Couplé à l'ensemble de ces études, une approche statistique a permis d'apporter une vision globale des paramètres produits qui influent sur les tissus 3D interlock chaine et les matériaux composites associés
The multi-scale characterisation of textile preforms made with natural fibres is a necessary method to understand and analyse the mechanical properties and behaviour of the composite. In this study, a multi-scale experimental characterisation is carried out on 3D warp interlock fabrics made with flax fibres at the fibre (micro), yarns (meso), fabric and composites (macro) scales. The mechanical tensile properties of the flax fibre were determined using the IFBT methodology. The twist effect was also taken into account in the calculation of fibre stiffness and revealed the limits of the rules of mixtures and some other models. Tensile tests on dry rovings were carried out considering different levels of twist, in order to determine the optimal twist level suited for 3D weaving process. The results reveal the importance of considering the properties of the fibre and the yarn at these scales to determine the most suitable material for weaving. At the fabric scale, seventeen 3D warp interlock fabrics were produced to understand the influence of product parameters on textile parameters and mechanical behaviour. The characterisation of 3D warp interlock woven structures shows the predominant role of yarns on structural and mechanical properties. On the following macroscopic scale, the six impregnated structures have enabled relationships to be established between the reinforcing structures and the associated composite materials. Coupled with these studies, a statistical approach provided a global vision of the product parameters that influence the 3D interlock warp interlock fabrics and the associated composite materials

Cette thèse s’intéresse au tissage et au préformage de renforts fibreux à base de fibres de lin. Avant d’être utilisés, ces fibres sont disposées en faisceaux de faible longueur (~ 30 mm en moyenne) et ont besoin d’être assemblées pour constituer un renfort linéaire continu. L’utilisation de rubans ou de rovings sans torsion est recommandée pour des applications composites. Dans un premier temps, cette étude se concentre sur l’élaboration et l’utilisation de rovings traités par un agent d’encollage et sans torsion ainsi que sur l’influence des paramètres du procédé de tissage sur les propriétés mécaniques et les caractéristiques textiles des renforts tissés. Pour éviter l’endommagement de ces rovings durant le tissage, des solutions sont proposées. Dans un second temps cette thèse s’intéresse à la mise en forme de ces renforts sur une géométrie complexe. Ce travail se concentre alors sur l’étape de préformage du procédé RTM. Une approche expérimentale est abordée pour identifier et quantifier les défauts apparaissant durant l’emboutissage sur une géométrie complexe comme le tétraèdre. Cette analyse se concentre en particulier sur le défaut de bouclage causé par un fléchissement des mèches. Des solutions comme l’optimisation de l’architecture des renforts sont observées pour obtenir cette géométrie complexe sans défaut avec des renforts à base de fibres de lin. La forme, le positionnement ainsi que la pression appliquée sur les serre-flans maintenant le renfort au cours du passage du poinçon influent également sur la génération des défauts. L’optimisation du procédé d’emboutissage pour empêcher l’apparition de boucles sur les préformes conclut ce travail
This work focuses on the weaving and forming of flax based reinforcements. Before being woven, naturalfibres on the form of finite length bundles (~ 30 mm in average for flax) need to be assembled together in a1D continuous product. The use of roving or slivers without twist is rather recommended for compositeapplications. In a first part, this study focuses on the manufacturing and the use of untwisted rovings treatedwith a bonding agent as well as on the weaving process parameters that may influence the mechanicalproperties and the textile characteristics of the woven fabric. Solutions to prevent roving defects duringweaving are proposed. In a second part, this study investigates the ability to develop composite parts with complex geometrieswithout defect. It focuses on the first step of RTM process which consists in forming dry fibrousreinforcements. An experimental approach is used to identify and quantify the defects. The buckling defectcaused by the bending of tows during the preforming step is particularly investigated. Solutions to realize acomplex shape such as a tetrahedron without any defect from flax based woven reinforcements areproposed. With optimized reinforcement architecture, buckling can be prevented. Another solutionconsisting in optimising the process parameters such as the blank holder geometry or the blank holderpressure to prevent the appearance of buckles from commercial fabrics was also investigated with success

Cette thèse a pour objectif la compréhension des propriétés mécaniques des composites à base de fibres de lin. Tout d’abord, on s’est focalisé sur les renforts tissés, ayant différents types de fils, structures et traitements, à travers une caractérisation multi-échelle. Les résultats montrent une forte influence du procédé du tissage ainsi que les traitements de désencollage et de séchage sur les propriétés mécaniques. L’étude montre une grande variabilité des propriétés mécaniques à l’échelle fil qui diminue significativement de l’échelle tissu à l’échelle composite où les résultats mettent en évidence des propriétés régulières et reproductibles, équivalentes aux composites à base de fibres synthétiques. Ensuite, cette thèse s’est intéressée aux propriétés mécaniques des renforts à orientation aléatoire, les non tissés. La caractérisation mécanique est réalisée sous forme sèche avec des essais de traction simple, de flexion pour différents lots de non tissé. Egalement, l’étude de la déformabilité des renforts non tissés est effectuée avec des essais d’emboutissage sur des géométries simple (hémisphère) et complexe (boite carrée). S’appuyant sur une approche expérimentale, un protocole de caractérisation est établi afin d’identifier et quantifier la réponse du non tissé lors de la mise en forme. L’apparition de nouveaux phénomènes tels que la variation de la densité locale et le glissement des fibres est observée pour les renforts de type non tissé. La caractérisation a démontré les effets de facteurs comme la géométrie du poinçon, la pression du serre-flan, la densité et la direction du renfort
This work focuses on understanding the mechanical properties of flax-based composites. First of all, a multi-scale characterization is carried out for oriented fabric with different types of yarns, structures and treatments. Parameters such as the weaving process and the existence of treatments like desizing and drying has a strong impact on the mechanical properties. Furthermore, the results shows a high variability of the mechanical properties at the yarn scale which decreases significantly at the fabric and composite equivalent properties with the synthetic fibres based composites. Secondly, the thesis focused on the mechanical properties of randomly oriented preforms known as nonwovens. The mechanical characterizations of flax fibre nonwoven are carried out with tensile, bending tests in the dry form. Then, forming tests of the non-woven preforms are performed with different geometries. Based on this experimental approach, a characterization protocol is established to identify and quantify their formability behavior. New phenomena such the variation of local density and the slippage of fibres network are observed for this type of reinforcement. The forming behavior depends strongly on the punch geometry, blank-holder, the area density and direction of the preform

Dans cette étude doctorale, nous proposons d’étudier la durabilité de deux matériaux composites à matrices thermodurcissable et thermoplastique renforcées par des tissus sergé de lin. Nous analysons d’abord la cinétique de diffusion d'eau dans les deux composites par identification de leurs paramètres de diffusion 3D, via une approche d’optimisation basée sur les modèles de Fick et de Langmuir 3D. Nous étudions ensuite l’effet de plusieurs paramètres géométriques et l’orientation des fibres sur la cinétique de diffusion d’eau au sein des deux composites. Nous analysons par la suite l'effet du vieillissement hydrique sur leurs propriétés élastiques et à la rupture. Enfin, nous proposons une analyse numérique par éléments finis de la diffusion d’eau au sein des deux composites et de leur comportement hydro-élastique. Nous estimons ainsi les paramètres de diffusion de la fibre de lin et des matrices à travers une approche numérique inverse, en décrivant la section et l’ondulation des mèches de lin au sein des deux matériaux. Nous montrons en particulier que les composites non vieillis présentent un comportement mécanique proche de l'effet Kaiser. Cependant, les composites vieillis présentent clairement un effet Felicity, ce qui indique la présence significative d’endommagements induits par l’absorption d'eau. Nous affirmons enfin que l’analyse numérique permet d’identifier d’importantes concentrations de contraintes pouvant induire des endommagements microstructuraux au sein des composites étudiés
In this thesis work, we study the durability of two twill flax fabrics reinforced thermosetting and thermoplastic composites. Firstly, the diffusion behaviour of these composites is investigated by identifying their 3D Fick’s and Langmuir’s diffusion parameters using an optimization algorithm. The influence of several geometric parameters and fibre orientation on their 3D moisture diffusion is also studied. Then, we analyse the effect of water ageing on their elastic and failure properties. Finally, a numerical finite element analysis is performed in order to study their diffusive and hydro-mechanical behaviour. The water diffusion parameters of the flax fibre and the used resins are estimated by a numerical inverse analysis exploiting experimental water uptake data. The heterogeneity of the studied composites is considered by modelling the twill weave fabrics undulation of their unit-cell. In particular, the mechanical behaviour of the unaged composites is found to exhibit a Kaiser effect contrary to the aged materials which exhibit a significant Felicity effect synonymous of substantial damage induced by water ageing. Besides, it is found that high mechanical stress concentrations are developed at the fibre-matrix interface, which could cause damage initiation and lead to the final composite failure

Cette thèse s’inscrit à mi-chemin entre l’étude de la déformabilité des structures tissées et la valorisation de la fibre de lin pour des applications dans le renforcement des matériaux composites. Le premier objectif de l’étude est de caractériser expérimentalement le comportement en flexion des mèches de différentes structures constituées de fibres de lin ainsi que des tissus de différentes armures. Les travaux ont abordé aussi des paramètres tels que l’humidité relative et la composition (des mèches comélées ou en lin pure). Le deuxième objectif des travaux est d’étudier le comportement en flexion des tissus en fonction du comportement en flexion des mèches. Cette partie a commencé par la modélisation géométrique des renforts tissés dans le but de suivre l’évolution de la section du tissu qui varie dans la direction de la flexion. La modélisation mésoscopique a permis de calculer analytiquement les propriétés géométriques du tissu en particulier son moment quadratique. Les résultats obtenus ont été utilisés dans la simulation de la flexion du tissu. L’étude a permis de voir jusqu’à quel point le comportement de la mèche et le moment quadratique du tissu pilotent le comportement en flexion du tissu. D’après ces travaux, le comportement en flexion du tissu semble être approché de façon satisfaisante sur toute la gamme de longueurs envisagées à partir de ces deux grandeurs sauf pour les forts taux d’humidité où d’autres phénomènes doivent être considérés. L’étude a souligné que la différence entre deux renforts testés expérimentalement peut être anticipée numériquement. Ainsi, le concepteur de tissus sera capable d’anticiper la rigidité expérimentale du tissu pour faire des tissages adaptés à la mise en forme du renfort. Une étude paramétrique de la flexion a été également réalisée dans le but de déduire les paramètres les plus influents sur lesquels il peut jouer
This thesis is halfway between the study of the deformability of woven structures and the use of flax fibre as reinforcement of composite materials. The first aim of the study is the experimental characterization of the bending behaviour of tows with different structures made of flax fibres and fabrics with different weaves. Parameters such as relative humidity and the composition (100% flax and commingled tows) were also considered. The second aim of the study is to link the bending behaviour of the fabric to the bending behaviour of its constituent tows. This part starts with the geometric modelling of woven fabrics in order to follow the variation of its section in the bending direction. Mesoscopic modelling allows the analytical calculation of the geometric properties of the fabric in particular its moment of inertia. The results obtained were used in the simulation of the fabrics bending to see how far the behaviour depends on the tows bending behaviour and the moment of inertia. The bending behaviour of the fabric seems to be approached satisfactorily from these two factors. This is verified within the range of lengths considered except for high humidity (in this case, other phenomena must be considered). The study pointed out that the difference between two reinforcements tested experimentally can be predicted numerically. Thus, the fabrics designer will be able to anticipate the experimental bending stiffness of the fabric in order to adapt the weaving to the shape forming. A parametric study of the bending was also achieved in order to deduce the most influential parameters of the fabric for an appropriate weaving

L'objectif du projet de thèse est d'étudier et d'analyser le comportement mécanique à l'impact et en post impact de composites à fibres végétales. Le déroulement de cette thèse nécessite : L'élaboration et la caractérisation des matériaux de l'étude : Les matériaux de l'étude seront constitués de tissus à fibres végétales (lin et/ou chanvre) imprégnées de résine thermodurcissable (de type époxyde) ou thermoplastique (de type PP ou PLA). Ceux-ci seront fabriqués sous forme de plaque par la technique d'infusion sous vide ou la technique de la thermocompression, en fonction du type de résine. La caractérisation mécanique sera effectuée à partir d'essais mécaniques statiques et d'essais d'impact avec une tour de chute (à plusieurs niveaux d'énergie). Celle-ci sera d'abord menée sur des éprouvettes modèles (non impactées et non vieillis, sans et avec renfort fibreux) puis sur des éprouvettes dégradées (impactées à chaque niveau d'énergie et vieillis en humidité et température). La caractérisation de l'endommagement : Elle permettra, à partir des analyses d'images associées aux techniques de l'émission acoustique, de localiser et d'identifier les différents mécanismes d'endommagement intervenant dans ces matériaux au cours des diverses sollicitations choisies. Cette étude conduira à définir le degré de nocivité de ces endommagements tout en associant à la démarche l'influence des paramètres microstructuraux tels que la nature du renfort fibreux et des constituants (résine et fibres). L'identification de modèles de comportement : Il s'agit de proposer une méthode d'identification des paramètres matériaux de modèles de comportement tenant compte de l'endommagement au niveau de la microstructure du matériau (résine et torons de fibres). Cette étude conduira à la mise en œuvre d'une méthode de type recalage de modèles éléments finis en utilisant les bases de données expérimentales constituées notamment des mesures de champs cinématiques. L'objectif à terme est de disposer de modèles fiables et prédictifs pour le calcul de structures de ces matériaux dans l'industrie
The purpose of this PhD project is to study and analyze the mechanical behavior during the impact and post-impact of plant-fiber based composite materials. The conduct of this thesis requires: The manufacturing and characterization of the materials involved in the study : The materials are composed of plant-fiber fabrics (flax and/or hemp) impregnated with thermosetting resin (epoxy type) or thermoplastic resin (PP or PLA). These are manufactured using the vacuum infusion process or using thermocompression, depending on the resin. The materials are plate-shaped. The mechanical characterization will be performed using static mechanical testing and impact testing with a drop tower (over several energy levels). This will be first conducted on unmodified specimens (unimpacted and unaged, with and without fiber reinforcement) then on degraded specimens (impacted with a known energy and/or aged in humidity and temperature). The characterization of damage: It will, from the analysis of the images associated to the techniques of the acoustic emission, locate and identify the various damage mechanisms that intervene in these materials during different stresses. This study will lead to define the degree of harmfulness of such damage while associating to the approach the influence of microstructural parameters such as the nature of the fiber reinforcement and the components (resin and fibers). The identification of behavioral patterns: It consists in suggesting a method to identify the material parameters of behavioral patterns while taking into account the damage level of the material's microstructure (resin and fiber strands). This study will lead to the implementation of a finite element model updating-like method using experimental databases such as kinematic field measurements. The ultimate purpose is to have reliable and predictive models in order to calculate the structures of such materials in the industry

Cette thèse porte sur la caractérisation et l’optimisation d’un pré-imprégné à base de résine époxy et de fibres de lin. Le renfort est constitué de tissus fabriqués par tissage de fils de lin torsadés. Les composites ont été élaborés par deux procédés : thermo-compression et enceinte autoclave. Chaque matériau a été testé en traction afin de déterminer ses propriétés mécaniques (élastique et à rupture). Les propriétés de sorption ont été étudiées grâce à des essais de vieillissement en immersion. Enfin, la capacité d’amortissement des composites lin/époxy a été déterminée à partir d’essais de vibration de poutres libres et comparée avec des composites carbone/époxy, verre/époxy et kevlar /époxy. Une étude systématique de l’influence des paramètres liés à chaque étape de l’élaboration des pré-imprégnés a été effectuée. Nous étudions l’effet du type du renfort (tissu ou asi-unidirectionnel), les paramètres associés au tissage (diamètre de fil, taux de remplissage) et l’influence de divers prétraitements textiles (appliqués aux fils ou aux tissus de lin). Un travail de modélisation est proposé, pour s’affranchir du taux de porosité, aussi bien sur les propriétés mécaniques que sur les propriétés de sorption. L’ensemble du travail effectué durant la thèse a pour objectif de déterminer les principales propriétés d’une gamme de pré-imprégnés lin/époxy à renforts tissés, et d’établir les conditions d’élaboration optimales pour optimiser leurs performances
This thesis focuses on the characterization and optimization of a prepreg based on epoxy resin and flax fibres. The reinforcement consists of fabrics made by twisted flax yarn. The composites were manufactured by two methods: hot platen press and autoclave chamber. Each material was tested using tensile tests to determine its mechanical properties (elastic and at break). Sorption properties were studied by immersion aging tests. Finally, the damping capacity of the flax/epoxy composite was determined from vibration tests of free beams and was compared with carbon/epoxy, glass/epoxy and kevlar/epoxy composites. A systematic study of the influence of the prepreg manufacturing parameters has been performed. We have studied the effect of the type of reinforcement (woven or quasi-unidirectional), the weaving parameters (yarn diameter, filling rate) and the influence of various textile pretreatments (applied to yarn or fabric). Some models are proposed to overcome the rate of porosity on the mechanical properties as well as on the sorption properties. The aim of this work is to identify the main properties of a range of flax/epoxy prepregs with woven reinforcement, and to establish optimal manufacturing conditions to optimize their performances

Ce mémoire de thèse de doctorat est structuré en deux parties. Dans la 1ère partie, une nouvelle approche traitant la caractérisation géométrique et mécanique est décrite. La modélisation géométrique de tissu 3D interlock est corrélée avec les paramètres de tissage afin de mieux prendre en compte ces paramètres. Le tissage de tissu 3D interlock est décrit en détail. Par la suite, une étude a été menée pour mieux comprendre les changements qui se produisent dans une mèche de carbone lorsque cette dernière est intégrée dans un renfort. Un coefficient de transfert des propriétés mécaniques a été proposé permettant une meilleure compréhension de l’influence des paramètres structuraux sur les propriétés d’un composite. Dans la 2eme partie du mémoire, un système de mesure in situ pour les composites a été développé. Ce système comporte un capteur souple et un module de traitement de données et d’amplification des signaux. Le capteur fibreux développé durant nos recherches a été inséré pendant le tissage comme un fil de trame. Le système a été testé sur une plaque en composite, contenant les renforts en 3D interlock, en traction. Le capteur suit fidèlement les déformations de la plaque composite jusqu’à la rupture
This thesis is divided in two parts. In the first part a geometrical modelling approach has been developed in tandem with weaving parameters. The reinforcements were woven on a modified conventional loom to study the geometry of these structures. Their weaving has been described in detail. The weaving parameters have been correlated to the modelling approach. The meso structural modelling approach is capable of predicting essential reinforcement geometrical characteristics at meso structural level without being too complicated. Furthermore, mechanical characterization of 3D interlock reinforcements has been carried out in such a way that a track of mechanical properties during the complete production cycle has been maintained. A novel parameter called strength transfer coefficient was proposed which allows better understanding of the influence of structural parameters on the final properties of the composite. In the second part of the thesis an online structural health monitoring system which is composed of a textile based sensor and signal amplification and treatment module, has been developed. This system is capable of detecting structural deformations in the composite as the sensor is integrated during the manufacturing of the reinforcement and can follow its deformation pattern when composite is subjected to tensile loading in a real time

This chapter includes detailed review of the research undertaken with conducting polymer (CP) based composites with chitosan (Ch) for tissue engineering till date. The beneficial role of electrically conductive biomaterials has been discussed with the possible strategies to overcome the shortcomings of CP alone through blending with Ch due to its excellent biocompatibility, biodegradability, and bioactivity. Additionally, this embodiment deals with the optimization and characterization of electrically conductive, biocompatible and biodegradable Polyaniline: Chitosan (PAni:Ch) nanocomposites as cell culture substrates for MDA-MB-231 and NIH 3T3 fibroblast in order to examine the combined effect of nanofiber structure and surface modification on cell-biomaterial interactions. The nanocomposites were further checked as a conductive scaffold for electrical stimulation of a neuronal model PC12 cell line in order to explore the potential of the materials in neural tissue engineering.

This chapter includes detailed review of the research undertaken with conducting polymer (CP) based composites with chitosan (Ch) for tissue engineering till date. The beneficial role of electrically conductive biomaterials has been discussed with the possible strategies to overcome the shortcomings of CP alone through blending with Ch due to its excellent biocompatibility, biodegradability, and bioactivity. Additionally, this embodiment deals with the optimization and characterization of electrically conductive, biocompatible and biodegradable Polyaniline: Chitosan (PAni:Ch) nanocomposites as cell culture substrates for MDA-MB-231 and NIH 3T3 fibroblast in order to examine the combined effect of nanofiber structure and surface modification on cell-biomaterial interactions. The nanocomposites were further checked as a conductive scaffold for electrical stimulation of a neuronal model PC12 cell line in order to explore the potential of the materials in neural tissue engineering.

Nanodiamond (ND) is an attractive nanomaterial for reinforcement of polymers [1] due to the ND’s superior mechanical and chemical properties, and low biotoxicity. A novel composite material has been produced for bone scaffolds utilizing the biodegradable polymer, poly(L-lactic acid) (PLLA), and octadecylamine-functionalized nanodiamond (ND-ODA) [2]. Composites were prepared by admixing to a PLLA/chloroform solution chloroform suspensions of ND-ODA at concentrations of 0, 1, 3, 5, 7, and 10 (w/w). Dispersion of ND-ODA in the composites was studied by transmission electron microscopy (TEM). The lower-resolution TEM micrograph of 1% wt ND-ODA/PLLA film (Fig. 1a) shows nanodiamond particles dispersed in PLLA film on amorphous carbon support. Due to long hydrocarbon chains of ODA the ND-ODA particles have good wettability with the PLLA so there is no segregation of ND-ODA and PLLA, and the polymer completely surrounds the particles. The high-resolution TEM image (Fig. 1b) shows ND crystals with attached organic material that can be ODA or PLLA. Nanoindentation tests show that the mechanical strength of ND-ODA/PLLA composites improves upon addition of ND (Table 1). Even at low concentrations (1% wt) the ND-ODA increased the hardness of the composite by 60% and Young’s modulus by 20% over neat PLLA. Based on our preliminary observations, we conclude that further additions of ND-ODA resulted in smaller changes with subsequent saturation in the mechanical properties at ∼7% wt (see Table 1). ND is relatively novel nanomaterial. Establishing its biocompatibility requires further studies, especially for modified ND. We studied the biocompatibility of 5–10nm ND and ND-ODA in experiments with a murine osteoblast cell line (7F2, from ATCC). Incubation of a cultured osteoblasts with 1–100μg/ml of ND or ND-ODA particles for 4 hours did not show much influence on the cell viability (Fig. 2), as inferred from an alamarBlue™ assay. To test the feasibility of ND-ODA/PLLA as a matrix material supporting cell growth, osteoblasts were cultured on the composites for 6 days. The attactment and proliferation of 7F2 cells on the scaffolds were assessed, respectively, by fluorescent nuclear staining with Hoechst 33258 and the alamarBlueTM assay. Our results showed that the addition of ND-ODA had only a negligibly small effect on cell proliferation, which is indicative of good biocompatibility of the composites (Fig. 3). The morphology of 7F2 cells growing on all ND-ODA/PLLA composite scaffolds was assessed by SEM. The data (not shown) confirm that the osteoblasts spread on the scaffolds similar to their spreading on TCP (tissue culture plastic). To summarize, the improved mechanical properties of the PLLA/ND-ODA composites and their good biocompatibility suggest that these materials may be suitable for applications in musculoskeletal tissue engineering.

Rupture of vascular tissue in the circulatory system under non-impact loading is involved in potentially life threatening events such as Marfan’s syndrome or rupture of small renal veins during shock wave lithotripsy. The rupture mechanisms are not well-understood. The complexity of the artery wall precludes the use of rupture theories invented for metals or for fibered composites with a homogeneous matrix. Artery tissue is composed of ground material, smooth muscle cells, elastin and collagen. The collagen fibers, which are generally circumferentially oriented, are the load carrying material after large deformations. Clark and Glagov [1] propose that the media of an elastic artery is built of musculo-elastic fascicles made up of a layer of circumferentially oriented SMC that lie parallel and between two elastin lamellae. Between the elastin sheets of adjacent elements are interspersed collagen fiber bundles.

Nano-scale materials and devices allow for unique interactions that are not possible at larger scales. Magnetic particles below a critical size (∼10 nm) demonstrate distinctive behavior known as superparamagnetism, where particles do not exhibit any net magnetic force outside the presence of an external magnetic field. However, within an alternating magnetic field, as in a magnetic resonance imaging (MRI) machine, superparamagnetic particles give off heat as a result of Brownian and Nee´lian relaxation. Heat produced by the shifting pole orientation can raise the temperature of the tissue sufficient to cause cell death through necrosis or apoptosis [1]. Additionally, combinations of electrically conductive and insulating materials within a single nanoparticle give rise to surface plasmon resonance. The resonance of the plasmon absorption can be tuned based on the relative thicknesses of the two layers. These particles can be used to thermally ablate cancer cells if the resonance is tuned to absorb light from an infrared laser. The penetrating ability of the nanoparticles combined with their capacity to kill cells make them excellent candidates for treatment of conditions such as brain tumors and prostate cancer.

Achieving cell adhesion, growth and homeostasis on an underlying biomaterial surface may be a desirable feature in implant device design and tissue engineering. Insight has been gained from numerous cell patterning strategies where spatial cues and physical constraints have been shown to regulate the structure and function of cells. Despite significant advances in modifying substrates for cellular attachment, migration and proliferation, the achievement of confluent and aligned growth of functional endothelial cells on cardiovascular blood-contacting implants under physiologically significant wall shear stress has proven difficult. Recently we have reported on a method that enhances cellular adhesion under flow conditions on synthetic polymer surfaces, without reliance on pro-adhesive protein biomaterials, which are often thrombogenic. In this method we utilize electron beam lithography and size-dependent self-assembly to fabricate line arrays of nanowells allowing entrapment and retention of charged nanoparticles, covalently conjugated with a RGD adhesive ligand, GRGDSPK. This approach is an additive strategy of combining substrata topographic alteration, electrostatic charge and biochemical ligands, all uniquely incorporated as an ensemble of charged, ligand-bearing nanoparticles entrapped in arrays of nanowells. However, the modulation of endothelial cell physiologic mechanisms as a result of ensemble surface exposure remains to be characterized. In this report, we extend our studies and probe cell physiologic mechanisms altered as a result of nanofeatured surface exposure. We first examined the functional intactness or normalcy of endothelial cells adherent to the nanofeatured ensemble surface utilizing standard immunostaining and flow cytometry methods. We found β1-integrin expression dominated quiescent adherent endothelial cells while αVβ3-integrins expression was more common in migratory cells. Endothelial cells were noted to express high levels of PECAM-1 over time when exposed to nanofeatured surface and RGD peptides. For understanding the contribution of the nanofeatured surface (entrapped RGD conjugated nanoparticles) to cell adhesion, cytochalasin B was used to alter cell spreading. Confocal microscopy illustrated the uptake of nanoparticles in endothelial cells on composite surfaces, as well as the inhibition of this endocytosis by cytochalasin B. After prohibiting the cells from engulfing nanoparticles, we found an 80% reduction in cell adhesion; suggesting that an endocytic mechanism might play a role in maintaining cell adhesion. Nanofeatured ensemble surfaces appear to be good substrates for achieving a high level of EC adhesion, with maintained growth and stability.