2,087 research outputs found

    Almost separating and almost secure frameproof codes over q-ary alphabets

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    The final publication is available at Springer via http://dx.doi.org/10.1007/s10623-015-0060-zIn this paper we discuss some variations of the notion of separating code for alphabets of arbitrary size. We show how the original definition can be relaxed in two different ways, namely almost separating and almost secure frameproof codes, yielding two different concepts. The new definitions enable us to obtain codes of higher rate, at the expense of satisfying the separating property partially. These new definitions become useful when complete separation is only required with high probability, rather than unconditionally. We also show how the codes proposed can be used to improve the rate of existing constructions of families of fingerprinting codes.Peer ReviewedPostprint (author's final draft

    gold thione complexes

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    The reaction of the ligand Et4todit (4,5,6,7-Tetrathiocino-[1,2-b:3,4-b']-diimidazolyl-1,3,8,10-tetraethyl-2,9-dithione) with gold complexes leads to the dinuclear gold(I) complexes [{Au(C6F5)}2(Et4todit)] and [Au(Et4todit)]2(OTf)2, which do not contain any gold-gold interactions, or to the gold(III) derivative [{Au(C6F5)3}2(Et4todit)]. The cristal structures have been established by X-ray diffraction studies and show that the gold centers coordinate to the sulfur atoms of the imidazoline-2-thione groups

    The Role of Metallodrugs in Cellular Senescence

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    Delivering alternative strategies to deal with cancer is a huge milestone in research. Cancer cells can give a senescence response as consequence of cellular stress or external stimuli such as the use of chemotherapies, which could end up eventually in cancer relapse. Controlling cellular senescence will surely open new cancer treatment approaches. Cancer senescence induction can be used as an added timeframe to look for alternative treatments and senolytic drugs to avoid cancer relapse destroying the senescent cells (SnCs). Within cancer senescence research, metal complexes are underdeveloped in comparison with that of organic molecules or nanoparticles. Herein, we highlight the scarce investigation performed with metal complexes in the field of senescence and how a great input on them could be a huge step towards the search of alternative cancer treatments

    Electronic structure and transport properties of atomic NiO spinvalves

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    Ab-initio quantum transport calculations show that short NiO chains suspended in Ni nanocontacts present a very strong spin-polarization of the conductance. The generalized gradient approximation we use here predicts a similiar polarization of the conductance as the one previously computed with non-local exchange, confirming the robustness of the result. Their use as nanoscopic spinvalves is proposed.Comment: 2 pages, 1 figure; accepted in JMMM (Proceedings of ICM'06, Kyoto

    Constructions of almost secure frameproof codes with applications to fingerprinting schemes

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    The final publication is available at Springer via http://dx.doi.org/10.1007/s10623-017-0359-zThis paper presents explicit constructions of fingerprinting codes. The proposed constructions use a class of codes called almost secure frameproof codes. An almost secure frameproof code is a relaxed version of a secure frameproof code, which in turn is the same as a separating code. This relaxed version is the object of our interest because it gives rise to fingerprinting codes of higher rate than fingerprinting codes derived from separating codes. The construction of almost secure frameproof codes discussed here is based on weakly biased arrays, a class of combinatorial objects tightly related to weakly dependent random variables.Peer ReviewedPostprint (author's final draft

    Theranostics Through the Synergistic Cooperation of Heterometallic Complexes

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    Heterometallic drugs are emerging as a great alternative to conventional metallodrugs. Careful selection of different metallic fragments makes possible to enhance not only the therapeutic potential by a synergistic effect, but also to incorpore key features like traceability. Drugs that integrate traceability and therapy in one system are known as theranostic agents. In cancer research, theranostic agents are becoming increasingly important. They deliver crucial information regarding their biological interplay that can ultimately be used for optimization. The well-established therapeutic potential of PtII-, RuII- and AuI-based drugs combined with the outstanding optical properties of d6 transition metal complexes grant the delivery of traceable metallodrugs. These species can be easily fine-tuned through modification of their respective ligands to provide a new generation of drugs

    Fenton and Photo-Fenton Nanocatalysts Revisited from the Perspective of Life Cycle Assessment

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    This study provides an overview of the environmental impacts associated with the production of different magnetic nanoparticles (NPs) based on magnetite (Fe3O4), with a potential use as heterogeneous Fenton or photo-Fenton catalysts in wastewater treatment applications. The tendency of Fe3O4 NPs to form aggregates in water makes necessary their decoration with stabilizing agents, in order to increase their catalytic activity. Different stabilizing agents were considered in this study: poly(acrylic acid) (PAA), polyethylenimine (PEI) and silica (SiO2), as well as the immobilization of the magnetite-based catalysts in a mesoporous silica matrix, SBA-15. In the case of photo-Fenton catalysts, combinations of magnetite NPs with semiconductors were evaluated, so that magnetic recovery of the nanomaterials is possible, thus allowing a safe discharge free of NPs. The results of this study suggest that magnetic nanoparticles coated with PEI or PAA were the most suitable option for their applications in heterogeneous Fenton processes, while ZnO-Fe3O4 NPs provided an interesting approach in photo-Fenton. This work showed the importance of identifying the relevance of nanoparticle production strategy in the environmental impacts associated with their useThis research was supported by two projects granted by Spanish Ministry of Science and Innovation: MODENA Project CTQ2016-79461-R and CLUSTERCAT Project MAT2015-67458-P, and Fundación Ramón Areces, Spain (Project CIVP18A3940). The authors belong to the Galician Competitive Research Groups ED431C-2017/22 and ED431C-2017/29 and CRETUS InstituteS

    Layer-by-layer biofabrication of coronary covered stents with clickable elastin-like recombinamers

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    Producción CientíficaCoronary artery disease is the leading cause of death around the world. Endovascular stenting is the preferred treatment option to restore blood flow in the coronary arteries due to the lower perioperative morbidity when compared with more invasive treatment options. However, stent failure is still a major clinical problem, and further technological solutions are required to improve the performance of current stents. Here, we developed coronary stents covered with elastin-like recombinamers (ELRs) by exploiting a layer-by-layer technique combined with catalyst-free click chemistry. The resulting ELR-covered stents were intact after an in vitro simulated implantation procedure by balloon dilatation, which evidenced the elastic performance of the membrane. Additionally, the stents were mechanically stable under high flow conditions, which is in agreement with the covalent and stable nature of the click chemistry crosslinking strategy exploited during the ELR-membrane manufacturing and the successful embedding of the stent. Minimal platelet adhesion was detected after blood exposure in a Chandler loop as shown by scanning electron microscopy. The seeding of human endothelial progenitor cells (EPCs) on the ELR-membranes resulted in a confluent endothelial layer. These results prove the potential of this strategy to develop an advanced generation of coronary stents, with a stable and bioactive elastin-like membrane to exclude the atherosclerotic plaque from the blood stream or to seal coronary perforations and aneurysms, while providing a luminal surface with minimal platelet adhesion and favouring endothelialization.German federal and state governments (project StUpPD_330-18)Ministerio de Economía, Industria y Competitividad (projects PCIN-2015-010 / MAT2016-78903-R)Junta de Castilla y León (project VA317P18

    Luminescent Thermochromism of 2D Coordination Polymers Based on Copper(I) Halides with 4-Hydroxythiophenol

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    This is the peer-reviewed version of the following article: Troyano, J., Perles, J., Amo‐Ochoa, P., Martínez, J. I., Concepción Gimeno, M., Fernández‐Moreira, V., ... & Delgado, S. (2016). Luminescent Thermochromism of 2D Coordination Polymers Based on Copper (I) Halides with 4‐Hydroxythiophenol. Chemistry–A European Journal, 22(50), 18027-18035., which has been published in final form at https://doi.org/10.1002/chem.201603675. This article may be used for non-commercial purposes in accordance with Wiley-VCH Terms and Conditions for Self-ArchivingSolvothermal reactions between copper(I) halides and 4-mercaptophenol give rise to the formation of three coordination polymers with general formula [Cu3X(HT)2]n(X=Cl, 1; Br, 2; and I, 3). The structures of these coordination polymers have been determined by X-ray diffraction at both room- and low temperature (110 K), showing a general shortening in Cu−S, Cu−X and Cu−Cu bond lengths at low temperatures. 1 and 2 are isostructural, consisting of layers in which the halogen ligands act as μ3-bridges joining two Cu1 and one Cu2 atoms whereas in 3 the iodine ligands is as μ4-mode but the layers are quasi-isostructural with 1 or 2. These compounds show a reversible thermochromic luminescence, with strong orange emission for 1 and 2, but weaker for 3 at room temperature, whereas upon cooling at 77 K 1 and 2 show stronger yellow emission, and 3 displays stronger green emission. DFT calculations have been used to rationalize these observations. These results suggest a high potential for this novel and promising stimuli-responsive materialsThis work was supported by MICINN (MAT2013-46753-C2-1-P). JIM acknowledges funding from the ERC-Synergy Program (Grant ERC-2013-SYG-610256 NANOCOSMOS) and computing resources from CTI-CSIC

    Mandible fracture in children: a case report

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    The type of maxillofacial fractures in children and young adults varies with evolving skeletal anatomy and social and environmental factors. The  general principles of treating mandibular fractures are the same for children and adults: Anatomic reduction along with rigid skeletal stabilization is mandatory until bone union has occurred. Here we present a female child with a fall trauma accident, presenting with fractures of the symphysis, horizontally and vertically unfavourable, with significant displacement. Open reduction and internal fixation with miniplates and screws was done, with good postoperative recovery and outcome. Keywords: maxillofacial fracture, paediatric trauma, skeletal stabilizatio
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