Suchergebnisse

Pan Shang,1,* Gan Chen,1,* Guannan Zu,2 Xiang Song,1 Peng Jiao,2 Guoxing You,1 Jingxiang Zhao,1 Hongyi Li,2 Hong Zhou11Academy of Military Medical Sciences, Institute of Health Service and Transfusion Medicine, Beijing 100850, People's Republic of China; 2Photoelectrochemical Research Group, School of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, People's Republic of China *These authors contributed equally to this workBackground: Cardiovascular disease (CVD) is the leading cause of mortality all over the world. Vascular stents are used to ameliorate vascular stenosis and recover vascular function. The application of nanotubular coatings has been confirmed to promote endothelial cell (EC) proliferation and function. However, the regulatory mechanisms involved in cellular responses to the nanotubular topography have not been defined. In the present study, a microarray analysis was performed to explore the expression patterns of long noncoding RNAs (lncRNAs) in human coronary artery endothelial cells (HCAECs) that were differentially expressed in response to nitinol-based nanotubular coatings.Materials and methods: First, anodization was performed to synthesize nitinol-based nanotubular coatings. Then, HCAECs were cultured on the samples for 24 h to evaluate cell cytoskeleton organization. Next, total RNA was extracted and synthesized into cRNA, which was hybridized onto the microarray. GO analysis and KEGG pathway analysis were performed to investigate the roles of differentially expressed messenger RNAs (mRNAs). Quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR) was performed to validate the expression of randomly selected lncRNAs. Coexpression networks were created to identify the interactions among lncRNAs and the protein-coding genes involved in nanotubular topography-induced biological and molecular pathways. Independent Student's t-test was applied for comparisons between two groups with statistical significance set at p<0.05.Results: 1085 lncRNAs and 227 mRNAs were significantly differentially expressed in the nitinol-based nanotubular coating group. Bioinformatics analysis revealed that extracellular matrix receptor interactions and cell adhesion molecules play critical roles in the sensing of nitinol-based nanotubular coatings by HCAECs. The TATA-binding protein (TBP) and TBP-associated transfactor 1 (TAF1) are important molecules in EC responses to substrate topography.Conclusion: This study suggests that nanotubular substrate topography regulates ECs by differentially expressed lncRNAs involved extracellular matrix receptor interactions and cell adhesion molecules.Keywords: nitinol titanium dioxide nanotubes, RNA sequencing, long noncoding RNA, nanotopography, molecular networks

Nan Jiang,1–3 Lu Chen,1–3 Qianli Ma,4,5 Jianping Ruan1–3 1Department of Preventive Dentistry, College of Stomatology, Xi'an JiaoTong University, Xi'an, People's Republic of China; 2Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an JiaoTong University, Xi'an, People's Republic of China; 3Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, College of Stomatology, Xi'an JiaoTong University, Xi'an, People's Republic of China; 4Department of Immunology, School of Basic Medicine, Fourth Military Medical University, Xi'an, People's Republic of China; 5Department of Prosthodontics, College of Stomatology, Xi'an JiaoTong University, Xi'an, People's Republic of China Purpose: To investigate the amelogenesis-inductive effects of surface structures at the nanoscale. For this purpose, variable nanostructured titanium dioxide (TiO2) surfaces were used as a framework to regulate the amelogenic behaviors of ameloblasts with the administration of retinoic acid (RA)/dexamethasone (DEX). Materials and methods: TiO2 nanotubular (NT) surfaces were fabricated via anodization. Mouse ameloblast-like LS-8 cells were seeded and cultured on NT surfaces in the presence or absence of RA/DEX for 48 h. The amelogenic behaviors and extracellular matrix (ECM) mineralization of LS-8 cells on nanostructured Ti surfaces were characterized using field emission scanning electron microscope, laser scanning confocal microscope, quantitative polymerase chain reaction, MTT assay, and flow cytometry. Results: TiO2 NT surfaces (tube size ~30 and ~80 nm) were constructed via anodization at 5 or 20 V and denoted as NT5 and NT20, respectively. LS-8 cells exhibited significantly increased spread and proliferation, and lower rates of apoptosis and necrosis on NT surfaces. The amelogenic gene expression and ECM mineralization differed significantly on the NT20 and the NT5 and polished Ti sample surfaces in standard medium. The amelogenic behaviors of LS-8 cells were further changed by RA/DEX pretreatment, which directly drove maturation of LS-8 cells. Conclusion: Controlling the amelogenic behaviors of ameloblast-like LS-8 cells by manipulating the nanostructure of biomaterials surfaces represents an effective tool for the establishment of a systemic framework for supporting enamel regeneration. The administration of RA/DEX is an effective approach for driving the amelogenesis and maturation of ameloblasts. Keywords: TiO2 nanotube, LS-8, surface nanostructure, amelogenesis, retinoic acid

In this study, magnetic nanocomposites were developed and used as adsorbents for lead and copper from aqueous media. Structural, surface, magnetic and textural properties of functionalized maghemite nanoparticles synthesized by alkaline co-precipitation were studied. The surfaces of the iron oxide nanoparticles (Nps) were modified with different chemical agents such as fatty and amino acids, silica (SiO2), mesoporous silica (SBA-15), hydroxyapatite, multiwall carbon nanotubes (MWCNTs) and ethylenediaminetetraacetic acid (EDTA), obtaining NPs with mean particle sizes ranging from 7 to 16 nm according to Rietveld refinement and TEM images analysis. The physicochemical surface properties of the functionalized materials were studied via zeta potential (zeta) and Fourier transform infrared (FTIR) spectroscopy. Mossbauer spectroscopy (MS) as a function of temperature and DC magnetometry were used to study the magnetic properties. The superparamagnetic relaxation was studied by MS. The resolved spectra at 20 K confirm the presence of nanomaghemite phase. Besides, the saturation magnetization varies from 12 to 62 emu g(-1). A nitrogen adsorption-desorption technique was used to determine the specific surface area and to study the porous structure. The functionalized gamma-Fe2O3 Nps exhibited a Brunauer-Emmett-Teller (BET) specific surface area ranging from 74 to 214 m(2) g(-1) and revealed remarkable uptake capacities to remove Cu(II) and Pb(II) species from aqueous solutions. ; National Council of Science, Technology and Technological Innovation (CONCYTEC/Cienciactiva-Peru) ; Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) ; DAAD ; Ministerio de Economia y Competitividad of Spanish Government ; Natl Univ San Marcos, Fac Phys Sci, POB 14-0149, Lima 14, Peru ; Tech Univ Carolo Wilhelmina Braunschweig, Inst Phys Kondensierten Mat, D-38110 Braunschweig, Germany ; Univ Fed Sao Paulo, Inst Ciencia & Tecnol, Ave Cesare Mansueto Giulio Lattes 1201, BR-12247014 Sao Jose Dos Campos, SP, Brazil ; Brazilian Ctr Res Phys CBPF, BR-22290180 Rio De Janeiro, RJ, Brazil ; Univ Fed Rio Grande do Norte, Dept Fis Teor & Expt, BR-59078970 Natal, RN, Brazil ; Univ Rey Juan Carlos, Environm & Chem Engn Grp, C Tulipan S-N, Madrid, Spain ; Instituto de Ciência e Tecnologia, Universidade Federal de São Paulo, Av. Cesare Mansueto Giulio Lattes, 1201, São José dos Campos, Brazil ; CNPq: 305748/2015-7 ; Ministerio de Economia y Competitividad of Spanish Government: CTM2015-69246-R ; Web of Science

Funding Information: The authors thank Mr. Andrei Starkov for illustrations and Mrs. Anastasiya Grebenko for assistance with sample synthesis. This work was performed using equipment of MIPT Shared Facilities Center. The authors acknowledge Vadim Khrapai and Evgeny Tikhonov (ISSP) for assistance with low temperature measurements and professor Galina Tsirlina (MSU) for fruitful discussions. The authors are also grateful to Salavat Khasanov for assistance and verification of XRD measurements. The authors thank the Helmholtz‐Zentrum Berlin für Materialien und Energie for the allocation of synchrotron radiation beamtime. Computations were done at the Finnish IT Center for Science, CSC. Russian Foundation for Basic Research grant # 19‐32‐90143 (A.K.G., A.G.N.). German Federal Ministry of Education and Research (BMBF) grant no. 05K19KER (A.A.M.). Russian Science Foundation No. 21‐19‐00226 (D.V.K., graphene synthesis). Russian Science Foundation No. 21‐72‐20050 (B.P.G., THz‐FIR spectroscopy). Ministry of Science and Higher Education of the Russian Federation within the governmental order for Boreskov Institute of Catalysis project АААА‐А21‐121011390011‐4 (A.N.S.). Partially supported by the Ministry of Science and Higher Education of the Russian Federation No. FSMG‐2021‐0005 (V.S.V., ARPES studies) and Russian Science Foundation No. 21‐72‐30026 (V.S.V, STM Studies). The work was supported by the Council on grants of the President of the Russian Federation grant number НШ‐1330.2022.1.3. Publisher Copyright: © 2022 The Authors. Advanced Science published by Wiley-VCH GmbH ; Following the game-changing high-pressure CO (HiPco) process that established the first facile route toward large-scale production of single-walled carbon nanotubes, CO synthesis of cm-sized graphene crystals of ultra-high purity grown during tens of minutes is proposed. The Boudouard reaction serves for the first time to produce individual monolayer structures on the surface of a metal catalyst, thereby providing a chemical vapor deposition technique free from molecular and atomic hydrogen as well as vacuum conditions. This approach facilitates inhibition of the graphene nucleation from the CO/CO2 mixture and maintains a high growth rate of graphene seeds reaching large-scale monocrystals. Unique features of the Boudouard reaction coupled with CO-driven catalyst engineering ensure not only suppression of the second layer growth but also provide a simple and reliable technique for surface cleaning. Aside from being a novel carbon source, carbon monoxide ensures peculiar modification of catalyst and in generalopens avenues for breakthrough graphene-catalyst composite production. ; Peer reviewed

Atomically dispersed metals maximize the number of catalytic sites and enhance their activity. However, their challenging synthesis and characterization strongly complicates their optimization. Here, the aim is to demonstrate that tuning the electronic environment of atomically dispersed metal catalysts through the modification of their edge coordination is an effective strategy to maximize their performance. This article focuses on optimizing nickel-based electrocatalysts toward alcohol electrooxidation in alkaline solution. A new organic framework with atomically dispersed nickel is first developed. The coordination environment of nickel within this framework is modified through the addition of carbonyl (CO) groups. The authors then demonstrate that such nickel-based organic frameworks, combined with carbon nanotubes, exhibit outstanding catalytic activity and durability toward the oxidation of methanol (CHOH), ethanol (CHCHOH), and benzyl alcohol (CHCHOH); the smaller molecule exhibits higher catalytic performance. These outstanding electrocatalytic activities for alcohol electrooxidation are attributed to the presence of the carbonyl group in the ligand chemical environment, which enhances the adsorption for alcohol, as revealed by density functional theory calculations. The work not only introduces a new atomically dispersed Ni-based catalyst, but also demonstrates a new strategy for designing and engineering high-performance catalysts through the tuning of their chemical environment. ; ICN2 is supported by the Severo Ochoa program from Spanish MINECO (Grant No. SEV-2017-0706) and is funded by the CERCA Programme /Generalitat de Catalunya. Part of the present work has been performed in the framework of Universitat Autònoma de Barcelona Materials Science Ph.D. program. Z.L. acknowledges funding from MINECO SO-FPT Ph.D. grant (SEV-2013-0295-17-1). This project has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 823717-ESTEEM3. The present work is supported by the European Regional Development Fund and by the Spanish MINECO through the projects ENE2016-77798-C4-3-R, ENE2017-85087-C3, and project NANOGEN (PID2020-116093RB-C43). X.W. and T.Z. thank the China Scholarship Council for the scholarship support. P. Tang acknowledges the Humboldt Research Fellowship. Authors acknowledge funding from Generalitat de Catalunya 2017SGR327 and 2017SGR1246. L.L. acknowledges the support from Natural Sciences and Engineering Research Council of Canada (NSERC, DG RGPIN-2020-06675). J.L. is a Serra Húnter Fellow and is grateful to MICINN/FEDER RTI2018-093996-B-C31, GC 2017 SGR 128, and to ICREA Academia program.

This editorial focuses on the important contribution that engineering and science of materials have to offer in thermal engineering applications, in particular, energy management.The search for innovative technologies is more than ever crucial to meet many future energy needs around the world. One example is thin-film technology that continuously grows into the global research field, following recognition that the properties of thin surface layers differ greatly from those of the same materials in bulk. The effects of increased surfacearea, in tandem with quantum effects, begin to dominate material properties. The development of nano-materials research is expected to play an increasing role in sustainable technologies for energy conversion, storage and savings. Areas of interest include solar cells, batteries, fuel cells, thermoelectrics, superconductors, multiferroics, magnetocalorics, and more recently hydrogen technologies.Incremental improvements in most of the current technologies are not sufficient to address the important issues of efficiency, durability and costs. Novel materials and innovative manufacturing approaches are therefore needed to design, elaborate and integrate materials for energy applications.Among promising materials technologies stand out carbon-nanotubes and graphene, which are suitable for low power consumption integrated circuits and applications in electronics. Carbon-based nanostructures are also investigated for solid state storage of hydrogen. In another line of work, proton exchange membrane fuel cell technology has also received increased attention as an efficient and environmentally friendly means of power generation in both stationary and mobile applications. Nano-material combinations could provide the performance required for miniaturized batteries to store solar energy and power smart cards.The low-cost superconductor technology is other promising field. Wires of high temperature superconductors are necessary for applications in power generation, transportation, transformation and storage. Beyond the incorporation in the energetic network, superconductor materials are also a key to develop new medical technologies based on magnetic resonance imaging performed in high magnetic fields. An important step has been a recent demonstration of the possibility of mass manufacturing of low cost superconducting tapes with innovative methodologies for deposition fromchemical solutions.Other innovative and promising processes are chemical vapor deposition of silicon nano-films and polymer coatings structured for solar cells and light-emitters, which are also potentially helpful for photovoltaics and optoelectronics.Within this nanotech revolution, there is an urgent need for more control and specific legislation against non-advised dissemination of nanomaterials. The properties and functionalities of specific nano-materials require long term studies for understanding their behavior in organisms and the environment.All these actions and initiatives involving materials are important and welcome because attract researchers from different fields, inspiring cooperation between multidisciplinary teams in Brazil.

A concise collection of the latest advances in chemical and biological agent detection and/or their surveillance written by leading experts in the field, The 9/11 attack on US soil has inadvertently heightened the need for preparation for other potential means of terrorist attack. In particular, both biological and chemical warfare have been at the top of the priority list for most governmental agencies as these reagents can be covertly prepared and disseminated to result in both widespread fear and casualty. Among many others, one primary preventive step in preparing for the above attacks is to establish a network for efficient surveillance and rapid detection such that an appropriate response to such attacks can be timely and effective. Over the years, primarily due to technological advances, both chemical and biological agents that are able to inflict mass destructions are becoming more diverse and complex. Subsequently, improvement of sensing devices for rapid and sensitive detection should also be made to keep pace with these engineered or emerging threat agents. Of particular interest, the ability to encompass advances in micro and nanofabrication techniques to enable sensing devices are especially of interest as they have been shown to offer desired advantages such as improved and enhanced functionality, increased efficiency and speed in their readout, reduction in their fabrication cost, and also reduced reagent consumption. Numerous innovative and exciting reports which took advantage of these techniques for both chemical and biological sensing have appeared over the last decade. This unique book is the only current publication that provides readers with a brief, yet concise, collection of the latest advances in chemical and biological agent detection and/or their surveillance. It compiles and gives in-depth detail on several detection schemes so that the reader can be provided with a general sense of these micro and nanoscale sensing systems and platforms. The book covers both well established and "next-generation" micro- and nano-scale sensors and/or sensing platforms. Sensors or sensing platforms covered range from the novel utilization of nanotubes, cantilevers, nano and/or microsized pores, engineered whole cell, to polymeric transistors for sensing purposes. As a result of these advances there has been a synergistic marriage of a myriad of techniques, ranging from chemical, engineering and biological, for the development of sensors, which was once traditionally thought to be reserved for the immunologists. The enabling of these new technologies will result in a much improved sensing network for the detection and surveillance of both chemical and biological warfare agents.The book also contains chapters from leading experts in the field of chemical and biological sensing platforms and will be invaluable reading for anybody in this field

Coupling thermoelectrics (TE) with photovoltaics (PV) has emerged as an approach to solid-state solar harvesting, directly converting light and infrared heat into electricity. In this work, we compare PV-TE hybrid devices based on organic semiconductors in three different geometries: a reflection geometry, a non-contact transmission geometry, and a contact transmission geometry. The temperature rises of films of common organic thermoelectric materials, including poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), single-walled carbon nanotubes (swCNT), and poly[2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene] (PBTTT), were measured in configurations representative of the proposed geometries. Because organic semiconductors possess broadband light absorption and low thermal conductivities, a significant rise in temperature was observed under illumination for all geometries. We find, however, that the best configuration is, in fact, the transmission contact mode because it sums two effects. Operating under 1 sun illumination, the temperature of a commercial organic PV module increased by ≈30 K, which leads to an enhancement in OPV performance compared to room temperature. After attaching a thermoelectric to the OPV module, losses from convection are reduced, and the OPV module heats up even more, further increasing its efficiency while additionally enabling thermoelectric generation. Finally, we calculate theoretical thermoelectric efficiencies for the materials and their respective power densities. ; The authors acknowledge financial support from the Spanish Ministry Science and Innovation through the "Severo Ochoa" Program for Centers of Excellence in R&D SEV-2015-0496 (FUNMAT) and CEX2019-000917-S (FUNFUTURE), and PGC2018-095411-B-I00 (RAINBOW) projects; from the Generalitat de Catalunya through grants 2017SGR488 and AGAUR 2018 PROD 00191; and from the European Research Council (ERC) under grant agreement no. 648901. This project has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no. 713673. J. P. J. has received financial support through the "la Caixa" INPhINIT Fellowship Grant for Doctoral studies at Spanish Research Centers of Excellence (Grant code: LCF/BQ/IN17/11620035), "la Caixa" Banking Foundation (ID100010434), Barcelona, Spain. O. Z. A. acknowledges CONACYT-SENER for his PhD scholarship (no. 472571). J. P. J. acknowledges the departments of Physics, Chemistry and Geology of the Autonomous University of Barcelona (UAB) as coordinators of the PhD programme in Materials Science. The authors thank Dr A. Roig, Dr A. Laromaine and Dr D. Abol-Fotouh (ICMAB-CSIC) for the CNT:cellulose sample preparation and fruitful discussions. The authors thank Dr Aleksandr Perevedentsev for his help with sample preparation, and Mr Pau Molet for his help with the FTIR measurements. We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI). ; Peer reviewed

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Materials and Interfaces, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acsami.9b13484 ; The production of MoS2 nanosheets by electrochemical exfoliation routes holds great promise as a means to access this two-dimensional material in large quantities for different practical applications. However, the use of electrolytes based on synthetic organic salts and solvents, as well as issues related to the unwanted oxidation and/or phase transformation of the exfoliated nanosheets, constitute significant obstacles that hinder the industrial adoption of the electrochemical approach. Here, we introduce a safe and sustainable method for the cathodic delamination of MoS2 that makes use of aqueous solutions of very simple and widely available salts, mainly KCl, as the electrolyte. Combined with an appropriate biomolecule-based solvent transfer protocol, such an electrolytic exfoliation route is shown to afford colloidally dispersed, oxide-free, and phase-preserved MoS2 nanosheets of high structural quality in considerable yields. The mechanisms behind the efficient aqueous delamination of the bulk MoS2 cathode are also discussed and rationalized on the basis of the penetration of hydrated cations from the electrolyte between its layers and the immediate reduction of the accompanying water molecules. An asymmetric supercapacitor assembled with a cathodic MoS2 nanosheet–single walled carbon nanotube hybrid as the positive electrode and activated carbon as the negative electrode delivered energy densities (e.g., 26 W h kg–1 at 750 W kg–1 in 6 M KOH) that were competitive with those of other MoS2-based asymmetric devices. When used as a catalyst for the reduction of nitroarenes, the present cathodically exfoliated nanosheets exhibited one of the highest activities reported so far with MoS2 nanostructures, the origin of which is accounted for as well. Overall, by facilitating access to this two-dimensional material through a particularly simple, efficient, and cost-effective technique, these results should expedite the practical implementation of MoS2 nanosheets in energy storage, catalysis, and beyond. ; Funding by the Spanish Ministerio de Economía y Competitividad (MINECO) and the European Regional Development Fund (ERDF) through project MAT2015-69844-R, the Spanish Ministerio de Ciencia, Innovación y Universidades and the ERDF through project RTI2018-100832-B-I00, and Plan de Ciencia, Tecnología e Innovación (PCTI) 2013-2017 del Principado de Asturias and the ERDF (project IDI/2018/000233) is gratefully acknowledged. S.G-D. and J.M.M. are grateful to Spanish MINECO and Ministerio de Educación, Cultura y Deporte (MECD), respectively, for their respective pre-doctoral contracts (BES/2016 077830 and FPU14/00792). The University of Oviedo acknowledges the financial support from Spanish MINECO (MAT2016-78155-C2-1-R) and the Government of the Principality of Asturias (GRUPIN-IDI/2018/170) ; Peer reviewed

Jinjin Wang,1,2,* Fanhui Meng,3,* Wen Song,3,* Jingyi Jin,2 Qianli Ma,2 Dongdong Fei,1 Liang Fang,2 Lihua Chen,2 Qintao Wang,1 Yumei Zhang3 1State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Department of Periodontology, School of Stomatology, The Fourth Military Medical University, Xi'an, Shannxi Province, China; 2Department of Immunology, School of Basic Medicine, The Fourth Military Medical University, Xi'an, Shannxi Province, China; 3State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shannxi Province, China *These authors contributed equally to this work Introduction: Fabricating nanostructured surface topography represents the mainstream approach to induce osteogenesis for the next-generation bone implant. In the past, the bone implant was designed to minimize host repulsive reactions in order to acquire biocompatibility. However, increasing reports indicate that the absence of an appropriate immune response cannot acquire adequate osseointegration after implantation in vivo. Materials and methods: We prepared different topographies on the surface of titanium (Ti) specimens by grinding, etching and anodizing, and they were marked as polished specimen (P), specimen with nanotubes (NTs) in small diameters (NT-30) and specimen with NTs in large diameters (NT-100). We evaluated the ability of different topographies of the specimen to induce osteogenic differentiation of mice bone marrow mesenchymal stem cells (BMSCs) in vitro and to induce osseointegration in vivo. Furthermore, we investigated the effect of different topographies on the polarization and secretion of macrophages, and the effect of macrophage polarization on topography-induced osteogenic differentiation of mice BMSCs. Finally, we verified the effect of macrophage polarization on topography-induced osseointegration in vivo by using Cre*RBP-Jfl/fl mice in which classically activated macrophage was restrained. Results: The osteogenic differentiation of mice BMSCs induced by specimen with different topographies was NT-100>NT-30>P, while the osseointegration induced by specimen with different topographies in vivo was NT-30>NT-100>P. In addition, specimen of NT-30 could induce more macrophages to M2 polarization, while specimen of P and NT-100 could induce more macrophages to M1 polarization. When co-culture mice BMSCs and macrophages on specimen with different topographies , the osteogenic differentiation of mice BMSCs was NT-30>NT-100≥P. The osseointegration induced by NT-100 in Cre*RBP-Jfl/fl mice was much better than that of wild type mice. Conclusion: It is suggested that the intrinsic immunomodulatory effects of nanomaterials are not only crucial to evaluate the in vivo biocompatibility but also required to determine the final osseointegration. To clarify the immune response and osseointegration may be beneficial for the designation and optimization of the bone implant. Keywords: nanomaterials, topography, immunomodulatory effects, macrophage polarization, osseointegration

This book looks at the democratic constructions surrounding public debates about issues related to scientific and technological development, specifically in this case nanotechnology. Brice Laurent argues that nanotechnology is a lens through which one can build a theoretical and practical approach to the study of contemporary democracies, exploring the joint production of nanotechnology itself and democratic order and identifying questions related to the exercise of citizenship, forms of national sovereignty, and channels of political legitimacy. This book helps increase visibility of and accessibility to STS methodologies for scholars and practitioners outside the field of science, technology, and society

Composite materials are widely used in engineering, especially in constructions working under simultaneous intensive mechanical and thermal loads. In the industry the main requirements for materials are restrictions on the elastic characteristics, such as bulk modulus and shear modulus.Composite materials consist of a base material, a so-called binder (matrix), and reinforcing inclusions. The composite matrix defines a method for the composite manufacturing and must meet a set of operational and technological requirements. The most commonly used types are a metal matrix and a polymer one, because of the relative ease of manufacture, good wettability, and chemical resistance.Reinforcing inclusions can be of different nature (boron, crystalline, etc.) and shape (spherical, lamellar, fiber). Lately, active researches have been conducted with the nanostructural elements (fullerenes, single-walled and multi-walled carbon nanotubes (SWCNTs and MWCNTs) plates, nanoclusters) used as the filler.There are various ways of modeling the elastic properties of the composites. The most common are numerical methods using a finite element method and analytical methods.In simulation of composite characteristics, in addition to the properties of its components, a reinforcing structure plays an important role.The paper considers an obtained isotropic composite with a metal matrix reinforced by the spherical nanoclusters of randomly oriented SWNTs with a reinforcement scheme similar to the cubic crystal lattice. Numerical modeling and analytical methods were used.For the numerical solution two types of periodic structure of the material were obtained: a cube with eight parts of the ball in the corners of a cube and a sphere in the center. For each of the periodic cells a representative volume is selected in which, using the kinematic and force boundary conditions, have been implemented two types of stress-strain state, namely stretching along one axis and shear. For numerical implementation was used a ANSYS software complex coupled with a specially designed software module that allows creating tensors of elastic coefficient and pliability of the composite, as well as averaging its elastic characteristics to have values of bulk and shear moduli of the material.The results of numerical simulations have been compared with the analytical estimates obtained by the self-consistent method and the dual formulation of the elasticity problem in a heterogeneous solid. It is found that in numerical implementation a choice of the composite periodic cell has a significant impact on the values of the shear modulus as opposed to the bulk modulus of elasticity. It is also shown that the numerical simulation results are between the estimates obtained using the analytical models. These results allow predicting the elastic properties of composites, reinforced by spherical inclusions, including advanced materials, i.e. nanocomposites reinforced by spherical nanoclusters of randomly oriented SWCNTs.The paper is done within the framework of implementing basic part of the Governmental task of the Ministry of Education and Science of the Russian Federation (Project 9.7784.2017/БЧ). ; Композиционные материалы получили широкое распространение в технике, особенно в конструкциях, работающих при одновременном интенсивном воздействии механических и тепловых нагрузок. Одними из основных требований, предъявляемых к материалам в той или иной отрасли, являются ограничения на упругие характеристики, например, объемный модуль упругости и модуль сдвига.Композиционные материалы состоят из основного материала, так называемого связующего (матрицы), и армирующих включений. Матрица композита определяет способ изготовления композита и должна удовлетворять набору эксплуатационных и технологических требований. Наиболее часто применяемыми в силу относительной простоты изготовления, хорошей смачиваемости и химической устойчивости являются металлическая и полимерная матрицы.Армирующие включения могут иметь различную природу (борные, кристаллические и т.д.) и форму (шаровые, пластинчатые, волокно). В последнее время активно проводят исследования, направленные на использование в качестве наполнителя наноструктурных элементов (фуллерены, однослойные и многослойные углеродные нанотрубки (ОУНТ и МУНТ), пластинки, нанокластеры).Существуют различные способы моделирования упругих свойств композитов. Наиболее распространенными являются численные методы с использованием метода конечных элементов и аналитические.Для моделирования характеристик композита важную роль, помимо свойств его составляющих, имеет структура армирования.В данной работе рассмотрен композит с изотропной металлической матрицей, упрочненный шаровыми нанокластерами из хаотично ориентированных ОУНТ, со схемой армирования, аналогичной кубической кристаллической решетке. В качестве способов моделирования рассмотрены и численный, и аналитические методы.Для численного решения рассмотрено два типа периодической структуры такого материала: куб с восьмыми частями шара в углах и куб с шаром в центре. Для каждой из периодических ячеек выбран представительный объем, на котором с помощью кинематических и силовых граничных условий (ГУ) были реализованы два типа напряженно-деформированного состояния: растяжение вдоль одной оси и сдвиг. Численная реализация была проведена с помощью программного комплекса ANSYS совместно со специально разработанным программным модулем, позволяющем формировать тензоры коэффициентов упругости и податливости композита, а также осреднять его упругие характеристики для получения значений объемного модуля упругости и модуля сдвига материала. Проведено сравнение результатов численного моделирования с аналитическими оценками, полученными методом самосогласования и с помощью двойственной формулировки задачи упругости в неоднородном твердом теле. Установлено, что при численной реализации на значения модуля сдвига, в отличие от объемного модуля упругости, значительно влияет выбор периодической ячейки композита. Также показано, что результаты численного моделирования лежат между оценками, полученными с помощью аналитических моделей. Приведенные результаты позволят прогнозировать упругие характеристики композитов, армированных шаровыми включениями, в том числе перспективных материалов – нанокомпозитов, упрочненных шаровыми нанокластерами из хаотично ориентированных ОУНТ.Работа выполнена в рамках реализации базовой части государственного задания Минобрнауки РФ (проект 9.7784.2017/БЧ).

In the last 25 years, great progress has been made in the development of new materials, which have changed our lives or are in the process of changing them. The advance has been made mainly in work with materials on a nanometric scale, creating so-called nanomaterials because they are made up, in 50% or more, by particles that have at least one of their external dimensions at 100 nanometers [1]. Some of the applications of these materials are presented in the paragraphs below. In industrial applications, nanomaterials are used to make various products. In biology and medicine, magnetic nanoparticles have been used as drug carriers in the treatment of cancer, pathogen-detecting agents, also in the separation of proteins and as filter objects for molecules. Furthermore, nanowires have been manufactured from these materials, nanofibers and nanotubes, that allow observing and manipulating intracellular biological processes [2]. In the case of agriculture, preliminary studies have been carried out that show the potential of nanomaterials to improve germination and seed growth, plant protection, detection of pathogens and pesticide and herbicide residues [3]. One of the most promising and best developed environmental applications of nanotechnology has been environmental remediation and water treatment, where nanomaterials can help purify water through different mechanisms, including adsorption of heavy metals and other contaminants, contamination and inactivation of pathogens and the transformation of toxic materials into less toxic compounds [4]. Electrochemical energy storage technology is critically important to portable electronics, transportation, and large-scale energy storage systems. There is an increasing demand for energy storage devices with high energy density and high power, long-term stability, security and low cost [5]. As a solution to this demand, nanomaterials are very promising for the future, surface engineering advances in the development of materials with high energy storage capacity, fast recharge capacity and better durability [6] As a military application of nanomaterials, organic explosives are developed in the fine powder state, with submicron to nanoscale particle size distributions. Due to the complexity of manufacturing, a unique industrial method is created to produce these materials: the instant spray evaporation process, however, there is still the challenge of manufacturing objects with these explosive powders due to the balance that must be reached between power, safety and reliability. [7] Nanomaterials have become very useful tools in the fields of chemistry, materials science, physics, and nanotechnology due to their unique physical, chemical, magnetic, optical, and electronic characteristics. Along with the development of these materials, new manufacturing processes are created, as well as characterization techniques that specific their study and modifications. ; En los últimos 25 años se ha presentado un gran avance en el desarrollo de nuevos materiales, que han cambiado nuestras vidas o están en proceso de cambiarlas. El avance se ha dado principalmente a escala nanométrica, creando materiales denominados nanomateriales porque están constituidos, en un 50% o más, por partículas que tienen al menos una de sus dimensiones externas menor a 100 nanómetros [1]. A continuación, se presentan algunas de las aplicaciones de estos materiales. Los nanomateriales se utilizan en numerosos productos y aplicaciones industriales. En biología y medicina, se han utilizado nanopartículas magnéticas como portadores de fármacos en el tratamiento del cáncer, agentes detectores de patógenos, en la separación de proteínas y como objetos de manipulación de moléculas, además, a partir de estos materiales se han fabricado nanocables, nanofibras y nanotubos que permiten observar y manipular procesos biológicos intracelulares [2]. En el caso de la agricultura se han realizado estudios preliminares que muestran el potencial de los nanomateriales para mejorar la germinación y el crecimiento de las semillas, la protección de las plantas, la detección de patógenos y de residuos de pesticidas y herbicidas [3]. Una de las aplicaciones medioambientales más prometedoras y mejor desarrolladas de la nanotecnología ha sido la remediación y el tratamiento del agua, donde diferentes nanomateriales pueden ayudar a purificar el agua a través de diferentes mecanismos, incluida la adsorción de metales pesados y otros contaminantes, la eliminación e inactivación de patógenos y la transformación de materiales tóxicos en compuestos menos tóxicos [4]. La tecnología de almacenamiento de energía electroquímica es de importancia crítica para la electrónica portátil, el transporte y los sistemas de almacenamiento de energía a gran escala. Existe una creciente demanda de dispositivos de almacenamiento de energía con alta densidad de energía y alta potencia, estabilidad a largo plazo, seguridad y bajo costo [5]. Los nanomateriales son muy prometedores para el futuro, la ingeniería de superficies avanza en el desarrollo de materiales con alta capacidad de almacenamiento de energía, capacidad de recarga rápida y mejor durabilidad [6]. Las grandes potencias militares a nivel mundial están desarrollando explosivos orgánicos en el estado de polvos finos con distribuciones de tamaño de partícula submicrónicas a nanoescaladas. para lo cual también se creó un método industrial único para producir estos materiales: el proceso de evaporación por pulverización instantánea, sin embargo, aún se tiene el desafío de fabricar objetos con estos polvos explosivos debido al equilibrio que se debe alcanzar entre potencia, seguridad y fiabilidad. [7] Los nanomateriales se han convertido en herramientas muy útiles en los campos de la química, la ciencia de los materiales, la física y la nanotecnología debido a sus características físicas, químicas, magnéticas, ópticas y electrónicas únicas. A la par con el desarrollo de estos materiales, se crean nuevos procesos de fabricación y también técnicas de caracterización que permitan su estudio y manipulación.

2011/2012 ; Fossil energy sources are non-renewable being an irreplaceable endowment produced from millennia of biological and geological processes, which means that on the human time-scale they cannot be naturally regenerated and are only available in a finite amount on earth. Scientific and technological data concerning renewable fuels are exponentially growing and in parallel the governments are more and more attracted by these more sustainable energy sources. Overall, solar energy is the most abundant and easily available renewable resource which, however, has its own problems such as neither constantly available nor distributed equally over the surface of the globe. Hydrogen and various bio-fuels, such as bio-ethanol, biodiesel or biogas, have the potentiality to store the solar energy, playing a crucial role in the development of future renewable energy strategies. Nevertheless, as a general comment, it is very difficult and expensive to harness enough power from them to match the effectiveness of non-renewable resources. Thus, it is a big challenge to develop new and high efficient approach to improve the efficiency in production and use of these renewable resources. Nanotechnology is a key area that can help solving this issue. In fact, by using the tools offered by nanotechnology, it is possible to obtain tailored nanostructured catalytic materials that show remarkably better performance than that currently achievable even with state-of- the-art materials. The fields of catalysis, electrocatalysis, photocatalysis and photoelectron- catalysis are all examples of where nanotechnology is deeply impacting on current science, and in particular in energy related applications. The main focus of this PhD thesis is on nanotechnology applied to material science to enhance the performances of various on two important energy-related processes: namely the Fuel Cells (especially the Direct Alcohol Fuel Cell - DAFC) and the hydrogen production process. The H2 production processes include the electrochemical H2 production approach (the water electrolysis technique) and the photocatalytical H2 production approach (the photocatalytic decomposition of water into H2 technique). In the both the energy conversion processes, TiO2 nanotube arrays (TNTA) architectures were used as substrates and the Palladium (Pd) nanoparticles (NPs) were used as supported nanocatalysts. Therefore the most important results in this thesis are the design, realization, functional testing and characterization of supported Pd nanocatalysts on various TiO2 substrates with tailored and well-defined structures, in addition their use for energy-related applications, which are organized as follows: In the Chapter 1, the general principles of the fuel cells technique; the electrolysis technique; the TNTA substrate architecture and the principles of photocatalytic processes for H2 production are outlined or described in details. In addition, the development status and the preparation strategies of catalysts for the alcohol electrochemical oxidation are introduced in this chapter. In the chapter 2, an overview of the main characterization techniques is reported, all of which have been used in this thesis, in order to study the reactivity and the morphological and chemical properties of the samples. The aim of the present chapter is not that of providing exhaustive information about all the techniques. Rather, it is expected to furnish to the reader the main elements to better appreciate the results obtained and described in the following chapters of this thesis. Since the catalytic performance of the nanocatalysts can be finely turned by their shape, which determines surface atomic arrangement and coordination. In the chapter 3,we report a novel method of metal NPs modification, denoted as Electrochemical Milling and Faceting (ECMF), by which large supported Pd NPs (35 nm) of low-index facets supported on TNTA substrate can be milled into many small NPs (7 nm) with some HIF or high density of step atoms. By this approach, the catalytic activity of supported Pd NPs was enhanced by an order of magnitude to the ethanol electrooxidation, and was even 3 times higher than the highest value reported so far. This new approach to the synthesis of HIF-Pd NPs allows one to control metal loading, particle size and surface structure, independently from each other. Furthermore, in a practical catalytic system, such as the DAFC; the electrolysis system and the photocatalytical H2 production system, the electrochemical activity of the supported catalysts is not the only one parameter which needs to be concerned about, the other parameters for the whole test system's establishment such as the selection and preparation of the substrate material also need to the carefully optimize. In the chapter 4, a new type of Ti network substrate with the TNTA on top was prepared and introduced into the DAFC test system and also used in the electrolysis and photocatalytical H2 production process. This kind of substrate solved the typical problems of the DAFC such as the fuel solution diffusion limitation and the stability of the as supported catalysts drop during the large current density discharge. It was also proved to be a good choice as the substrate for the Photocatalytic decomposition of alkaline ethanol aqueous into H2, which showed good performances of the H2 photochatalytic evolution. Chapter 5 is the conclusion of my PhD thesis. The results clearly demonstrate the novelty and the advantage of the present approach for the obtainment of active and stable electrochemical catalysts for the DAFC and the electrolysis system, and also represent an important step forward in the exploration of new active nanosystems for the conversion of solar light into storable chemical energy. All the findings greatly contributed to the development of catalytic materials for energy-related applications. ; XXV Ciclo ; 1983

Memoria presentada por Beatriz Sánchez Page, graduada en Química y Máster en Química Molecular y Catálisis Homogénea, para optar al grado de Doctor en Ciencias, en el programa de Doctorado en Química Inorgánica. Esta Tesis Doctoral se presenta en la modalidad de Tesis por compendio de publicaciones. ; [ES]: El trabajo desarrollado en esta Memoria se ha centrado en el diseño, síntesis, caracterización y estudios de estabilidad de compuestos moleculares de rodio e iridio soportados en materiales nanoestructurados de carbono. La actividad catalítica de los nuevos materiales híbridos y la de los complejos moleculares relacionados de rodio e iridio se ha evaluado en la hidrosililación de alquinos y en la oxidación química y electroquímica de agua, respectivamente. Los complejos de rodio(I) y (III) soportados en un óxido de grafeno reducido térmicamente a 400 ºC por enlace covalente carbono-nitrógeno entre un ligando NHC mesoiónico (4-fenil-3-metil-1,2,3-triazol-5-ilideno) y la pared del grafeno, Rh(I)/Rh(III)-NHC@TRGO, y los complejos moleculares relacionados muestran alta actividad en la hidrosililación de alquinos y una excelente regio- y estereoselectividad al isómero cinético β-(Z)-vinilsilano. Concretamente, el catalizador ciclometalado [Cp*RhI(C,C')-Triaz] (Triaz = 1,4-difenil-3-metil-1,2,3-triazol-5-ilideno) es un catalizador sobresaliente en la hidrosililación de alquinos terminales, alifáticos y aromáticos, a temperatura ambiente con completa regio- y estereoselectividad al isómero β(Z)-vinilsilano. Por otro lado, aunque el catalizador híbrido relacionado de rodio(III)-triazolilideno no es activo a temperatura ambiente, muestra la misma actividad y selectividad que el catalizador homogéneo a 60 °C. Adicionalmente, los catalizadores híbridos basados en grafeno modificado Rh-NHC@TRGO son completamente reciclables en la hidrosililación de alquinos con excelente control de la selectividad β-(Z). Los estudios por DFT del mecanismo de hidrosililación para el catalizador molecular de Rh(III) evidencian la posible participación de un mecanismo bifuncional metal-ligando basado en una ciclometalación reversible. Los materiales híbridos basados en complejos Ir(I)-NHC anclados a nanotubos de carbono a través de grupos éster, Ir(I)-NHC@CNT, son catalizadores eficientes en la oxidación química y electroquímica de agua. El estudio ha revelado que tanto los catalizadores moleculares homogéneos como los heterogéneos que poseen un ligando NHC funcionalizado con un grupo sulfonato son mucho más activos que los catalizadores moleculares relacionados con ligandos NHC no hidrosolubles, tanto en la oxidación química de agua, con CAN como oxidante de sacrificio, como en la oxidación electroquímica en la que se alcanzan valores de TOF de hasta 22000 h-1 a 1.4 V para el catalizador híbrido NHC-sulfonato. Por otro lado, se ha observado que la estructura grafítica del soporte juega un papel importante en el rendimiento electrocatalítico de oxidación de agua con complejos de iridio(I)-NHC soportados por enlace carbonato a dos óxidos de grafeno de diferente estructura grafítica. Se ha comprobado que el desplazamiento del ligando cloruro en los centros metálicos de iridio por grupos oxigenados de la pared nanoestructurada del grafeno tiene un impacto negativo en la actividad electrocatalítica del catalizador híbrido resultante. ; [EN]: The work developed in this Memory has been focused on the design, synthesis, characterization and stability studies of rhodium and iridium molecular compounds supported on carbon nanostructured materials. The catalytic activity of the new hybrid materials together and that of related molecular complexes of rhodium and iridium has been evaluated in the hydrosilylation of alkynes and in the chemical and electrochemical water oxidation, respectively. Rhodium(I) and (III) complexes supported on a thermally reduced graphene oxide at 400 °C by carbon‐nitrogen covalent bond between a mesoionic NHC ligand (4‐phenyl‐3‐methyl‐1,2,3‐triazole‐5‐ylidene) and the graphene wall, Rh(I)/Rh(III)‐NHC@TRGO, and related molecular complexes show high catalytic activity in hydrosilylation of alkynes with excellent regio‐ and stereoselectivity to the kinetic β‐(Z) vinylsilane isomer. Remarkably, the cyclometalated catalyst [Cp*RhI(C,C')‐Triaz] (Triaz = 1,4‐diphenyl‐3‐methyl‐1,2,3‐triazol‐5‐ylidene) shows an outstanding performance in the hydrosilylation of terminal, aliphatic and aromatic, alkynes with various hydrosilanes at room temperature with full regio‐ and stereoselectivity to β‐(Z)‐vinylsilanes. On the other hand, the related rhodium(III) triazolylidene hybrid catalyst is not active at room temperature although it shows an excellent catalytic performance at 60 °C. In addition, the hybrid catalysts based on modified graphene, Rh‐NHC@TRGO, are fully recyclable in alkyne hydrosilylation with excellent β-(Z) selectivity control. DFT studies on the alkyne hydrosilylation mechanism by the Rh(III) molecular catalyst point to the possible participation of a bifunctional metal‐ligand mechanism based on a reversible cyclometalation. The hybrid materials based on Ir(I)‐NHC complexes covalent attached to carbon nanotubes through ester functions, Ir(I)‐NHC@CNT, are efficient chemical and electrochemical water oxidation catalysts. The study has revealed that both homogeneous and heterogeneous molecular catalysts featuring NHC ligands functionalized with a sulfonate group are much more active than the related molecular catalysts lacking hydrosoluble NHC ligands, both in water chemical oxidation, using CAN as a sacrificial oxidant, or in electrochemical oxidation with TOF values up to 22000 h‐1 at 1.4 V for the sulfonate functionalized hybrid catalyst. On the other hand, it has been observed that the graphitic structure of the supports plays an important role in the water oxidation electrocatalytic performance of Ir(I)‐NHC complexes supported by carbonate bonding to two graphene oxides with different graphitic structure. A negative impact on the electrocatalytic activity has been found for the hybrid catalysts where the chloride ligand in the coordination sphere of the iridium metal centers has been displaced by oxygenated groups on the graphene nanostructured wall. ; Projects CTQ2016-75884-P, RTI2018-098537-B-C22, PID2019-103965GB-100, CTQ2013-42532-P and the Regional Governments of Aragón/FEDER/DGA 2014-2020 "Building Europe from Aragón" (groups E42_17R and E12_17R) and Principado de Asturias (FEDER: IDI/2018/000121). ; Peer reviewed