617 research outputs found

    Extraction of Features from the Palm for Identification of Persons

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    Práca sa zaoberá identifikáciou osôb pomocou dlane. Využívaju sa špecifické vlastnosti kože a ciev. K zachyteniu týchto vlastností sa využíva reakcia kože a ciev na elektromagnetické žiarenie. Pri extrahovaní vlastností kože sa využíva Gáborov filter. Pre extrahovanie žíl sa používa algoritmus LLBP. K porovnávaniu vlastností využíva Hammingova vzdialenosť, Euklidova vzdialenosť a klasifikátor najbližšieho suseda.The work deals with the identification of persons using the palm. The specific properties of the skin and blood vessels are used. The response of the skin and blood vessels to electromagnetic radiation is used to capture these properties. Gabor's filter is used to extract skin properties. The LLBP algorithm is used to extract the veins. It uses the Hamming distance, the Euclidean distance and the K-nearest neighbor algorithm to compare properties.

    Evolution from Covalent to Self-Assembled PAMAM-Based Dendrimers as Nanovectors for siRNA Delivery in Cancer by Coupled In Silico-Experimental Studies. Part I: Covalent siRNA Nanocarriers

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    Small interfering RNAs (siRNAs) represent a new approach towards the inhibition of gene expression; as such, they have rapidly emerged as promising therapeutics for a plethora of important human pathologies including cancer, cardiovascular diseases, and other disorders of a genetic etiology. However, the clinical translation of RNA interference (RNAi) requires safe and efficient vectors for siRNA delivery into cells. Dendrimers are attractive nanovectors to serve this purpose, as they present a unique, well-defined architecture and exhibit cooperative and multivalent effects at the nanoscale. This short review presents a brief introduction to RNAi-based therapeutics, the advantages offered by dendrimers as siRNA nanocarriers, and the remarkable results we achieved with bio-inspired, structurally flexible covalent dendrimers. In the companion paper, we next report our recent efforts in designing, characterizing and testing a series of self-assembled amphiphilic dendrimers and their related structural alterations to achieve unprecedented efficient siRNA delivery both in vitro and in vivo

    Perceptions and Misconceptions in Molecular Recognition: Key Factors in Self-Assembling Multivalent (SAMul) Ligands/Polyanions Selectivity

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    Biology is dominated by polyanions (cell membranes, nucleic acids, and polysaccharides just to name a few), and achieving selective recognition between biological polyanions and synthetic systems currently constitutes a major challenge in many biomedical applications, nanovectors-assisted gene delivery being a prime example. This review work summarizes some of our recent efforts in this field; in particular, by using a combined experimental/computation approach, we investigated in detail some critical aspects in self-assembled nanomicelles and two major polyanions-DNA and heparin

    Cationic carbosilane dendrimers and oligonucleotide binding: an energetic affair

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    GENERATION 2 CATIONIC CARBOSILANE DENDRIMERS HOLD GREAT PROMISE AS INTERNALIZING AGENTS FOR GENE THERAPY AS THEY PRESENT LOW TOXICITY AND RETAIN AND INTERNALIZE GENETIC MATERIAL AS OLIGONUCLEOTIDE OR SIRNA. IN THIS WORK WE CARRIED OUT A COMPLETE IN SILICO STRUCTURAL AND ENERGETICAL CHARACTERIZATION OF THE INTERACTIONS OF A SET OF 2G CARBOSILANE DENDRIMERS, SHOWING DIFFERENT AFFINITY TOWARDS TWO SINGLE STRAND OLIGONUCLEOTIDE (ODN) SEQUENCES IN VITRO. OUR SIMULATIONS PREDICT THAT THESE FOUR DENDRIMERS AND THE RELEVANT ODN COMPLEXES ARE CHARACTERIZED BY SIMILAR SIZE AND SHAPE, AND THAT THE MOLECULE-SPECIFIC ODN BINDING ABILITY CAN BE RATIONALIZED ONLY CONSIDERING A CRITICAL MOLECULAR DESIGN PARAMETER: THE NORMALIZED EFFECTIVE BINDING ENERGY \u394GBIND,EFF/NEFF I.E., THE PERFORMANCE OF EACH ACTIVE INDIVIDUAL DENDRIMER BRANCH DIRECTLY INVOLVED IN A BINDING INTERACTIO

    Evolution from Covalent to Self-Assembled PAMAM-Based Dendrimers as Nanovectors for siRNA Delivery in Cancer by Coupled in Silico-Experimental Studies. Part II: Self-Assembled siRNA Nanocarriers

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    In part I of this review, the authors showed how poly(amidoamine) (PAMAM)-based dendrimers can be considered as promising delivering platforms for siRNA therapeutics. This is by virtue of their precise and unique multivalent molecular architecture, characterized by uniform branching units and a plethora of surface groups amenable to effective siRNA binding and delivery to e.g., cancer cells. However, the successful clinical translation of dendrimer-based nanovectors requires considerable amounts of good manufacturing practice (GMP) compounds in order to conform to the guidelines recommended by the relevant authorizing agencies. Large-scale GMP-standard high-generation dendrimer production is technically very challenging. Therefore, in this second part of the review, the authors present the development of PAMAM-based amphiphilic dendrons, that are able to auto-organize themselves into nanosized micelles which ultimately outperform their covalent dendrimer counterparts in in vitro and in vivo gene silencing

    Chiral recognition at self-assembled multivalent (SAMul) nanoscale interfaces – enantioselectivity in polyanion binding

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    Self-assembled multivalent (SAMul) ligands based on palmitic acid functionalised with cationic L/D-lysine bind polyanionic heparin or DNA with no chiral preference. Inserting a glycine spacer unit switches on chiral discrimination – a rare example of controlled chiral recognition at a SAMul nanoscale interface

    Thermoplastic Materials for the Metal Replacement of Non-Structural Components in Marine Engines

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    Metal replacements for automotive and aerospace components are already a consolidated reality, in light of the advantages offered by fibre-reinforced polymers, consisting of reduced costs, weight, and environmental impact. As a result, engineering has been studying the possibility of replacing currently used metallic alloys with alternative materials, such as thermoplastic fibre-reinforced polymers, in the manufacturing of non-structural sections of marine engines. Given the peculiar characteristics of the working environment of such parts, i.e., ship engine spaces, and the strict requirements regarding safety, the selection of the polymer must be properly performed through a tailored material design process. Consequently, the redesign of the components must be carried out with the aim of exploiting the best of the materials’ properties while ensuring the correct resistance and simplifying installation operations. In this framework, finite element simulations may represent a suitable approach to validate the conformity of the proposed material and design. In this paper, this methodology is applied to a camshaft cover of a four-stroke marine engine, currently made of aluminium alloy. A 30% wt GFs/PA6,6 was identified as the most promising material and the novel plastic cover proved to guarantee the correct resistance while ensuring an important reduction in weight, processing costs, and required energy

    Novel epigenetic therapeutic strategies and targets in cancer

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    The critical role of dysregulated epigenetic pathways in cancer genesis, development, and therapy has typically been established as a result of scientific and technical innovations in next generation sequencing. RNA interference, histone modification, DNA methylation and chromatin remodelling are epigenetic processes that control gene expression without causing mutations in the DNA. Although epigenetic abnormalities are thought to be a symptom of cell tumorigenesis and malignant events that impact tumor growth and drug resistance, physicians believe that related processes might be a key therapeutic target for cancer treatment and prevention due to the reversible nature of these processes. A plethora of novel strategies for addressing epigenetics in cancer therapy for immuno-oncological complications are currently available - ranging from basic treatment to epigenetic editing. - and they will be the subject of this comprehensive review. In this review, we cover most of the advancements made in the field of targeting epigenetics with special emphasis on microbiology, plasma science, biophysics, pharmacology, molecular biology, phytochemistry, and nanoscience

    Highly grafted polystyrene/polyvinylpyridine polymer gold nanoparticles in a good solvent: effects of chain length and composition

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    In this work, the structural features of spherical gold nanoparticles (NPs) decorated with highly grafted poly(styrene) (PS), poly(vinylpyridine) (PVP) and PS\u2013PVP diblock copolymer brushes immersed in a good solvent are investigated by means of Dissipative Particle Dynamics (DPD) simulations as a function of grafted chain length and of homopolymer and copolymer chain composition. For NPs grafted either by PS or PVP homopolymer brushes (selected as a proof of concept), good agreement between the Daoud\u2013Cotton theory, experimental evidence, and our DPD simulations is observed in the scaling behavior of single chain properties, especially for longer grafted chains, and in brush thickness prediction. On the other hand, for grafted chain lengths comparable to NP dimensions parabolic-like profiles of the end-monomer distributions are obtained. Furthermore, a region of high concentration of polymer segments is observed in the monomer density distribution for long homopolymers. In the case of copolymer-decorated NPs, the repulsion between PS and PVP blocks is found to substantially influence the radius of gyration and the shape of the end-monomer distribution of the relevant polymer shell. Moreover, for diblock chains, the un-swollen region is observed to be thinner (and, correspondingly, the swollen layer thicker) than that of a NP modified with a homopolymer of the same length. Finally, the lateral segregation of PS and PVP blocks is evidenced by our calculations and a detailed analysis of the corona behavior is reported, thus revealing the key parameters in controlling the surface properties and the response of diblock copolymer modified nanoparticles

    Consumer outrage: Emotional reactions to unethical corporate behavior ☆

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    Unethical corporate conduct frequently leads to public outrage, which in turn triggers detrimental consumer behavior, such as consumer boycotts. However, few studies examine the effects of unethical corporate behavior on consumer emotions. To address this gap, the present work develops and validates a model of consumer outrage. The analysis suggests that consumer outrage is a compound emotion that comprises affective and cognitive experiences. Moreover, the results indicate that consumer outrage is a major trigger of boycotting behavior and that gender affects the predictions of the outrage model. The paper provides implications for management and suggestions for further research
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