188 research outputs found

    Editorial Catalysts: Supported Metal Catalysts and Their Applications in Fine Chemicals

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    Editorial to the Special" Issue Supported Metal Catalysts and Their Applications in Fine Chemicals

    Comparison between fermentation and ultrasound‐assisted extraction: Which is the most efficient method to obtain antioxidant polyphenols from sambucus nigra and punicagranatum fruits?

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    Fruit extracts of Sambucus nigra L. (elderberry) and Punica granatum L. (pomegranate) have several applications in nutraceutical, cosmetics, and pharmaceutical industries thanks to their richness in antioxidant polyphenols, whose composition changes with the extraction method applied. We aimed to compare the efficiency of the fermentation extraction, recently applied by industries, with the ultrasound‐assisted extraction–UAE, a well‐known and efficient technique, on the yield of antioxidant polyphenols from elderberry fruits and pomegranate fruit‐peels. Extracts were obtained by both methods, analyzed by high‐performance liquid chromatography (HPLC) and the antioxi-dant capacities were evaluated using 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and Hydroxyl Radical Scavenging (HRS) assays. The main compounds detected in elderberry were caffeoyl and quercetin derivatives, present in higher amounts in UAE extracts. In pomegranate, punicalagin were the main constituents, also detected in higher contents in the UAE extracts compared to fermented ones. The UAE was more suitable for extracting anthocyanins from pomegranate. In addition, higher antiox-idant capacities were observed in UAE extracts, possibly due to their richness in polyphenols. Therefore, despite the recent wide applicability and the good performance of the fermentation pro-cess, the UAE may be considered more efficient for the extraction of polyphenols from S. nigra and P. granatum fruits and may be used to obtain polyphenolic antioxidant extracts to be applied by several industries

    Unravelling main- and side-chain motions in polymers with NMR spectroscopy and relaxometry: The case of polyvinyl butyral

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    Polyvinyl butyral (PVB) is an amorphous polymer employed in many technological applications. In order to highlight the relationships between macroscopic properties and dynamics at a microscopic level, motions of the main-chain and of the propyl side-chains were investigated between Tg − 288◩ C and Tg + 55◩ C, with Tg indicating the glass transition temperature. To this aim, a combination of solid state Nuclear Magnetic Resonance (NMR) methods was applied to two purposely synthesized PVB isotopomers: one fully protonated and the other perdeuterated on the side-chains.1 H time domain NMR and1 H field cycling NMR relaxometry experiments, performed across and above Tg, revealed that the dynamics of the main-chain corresponds to the α-relaxation associated to the glass transition, which was previously characterized by dielectric spectroscopy. A faster secondary relaxation was observed for the first time and ascribed to side-chains. The geometry and rate of motions of the different groups in the side-chains were characterized below Tg by2 H NMR spectroscopy

    Supported tris-triazole ligands for batch and continuous-flow copper-catalyzed huisgen 1,3-dipolar cycloaddition reactions

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    The lack of supported versions of the tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine (TBTA) ligand, suitable for flow-chemistry applications at scale, prompted us to develop a new route for the immobilization of such tris-triazole chelating units on highly cross-linked polystyrene resins. With this aim, the preparation of the known TBTA-type monomer 3 was optimized to develop a high-yield synthetic sequence, devoid of chromatographic purifications at any stage. Then, bead-type (P7) and monolithic (M7) functional resins were obtained by the easy and scalable suspension-or mold-copolymerization of 3 with divinylbenzene. Both types of materials were found to possess a highly porous morphology and specific surface area in the dry state and could be charged with substantial amounts of Cu(I) or Cu(II) salts. After treatment of the latter with a proper reducing agent, the corresponding supported Cu(I) complexes were tested in the copper-catalyzed alkyne-azide cycloaddition reaction (CuAAC). The immobilized catalysts proved active at room temperature and, in batch and with catalyst loadings as low as 0.6 mol%, afforded quantitative conversions within 20 h. Independent of the alkyne structure, extended use of the supported catalyst in flow was also possible. In the reaction of benzylazide and propargyl alcohol, this allowed a total turnover number larger than 400 to be reached

    Heart transplantation and biomarkers: a review about their usefulness in clinical practice

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    Advanced heart failure (AdvHF) can only be treated definitively by heart transplantation (HTx), yet problems such right ventricle dysfunction (RVD), rejection, cardiac allograft vasculopathy (CAV), and primary graft dysfunction (PGD) are linked to a poor prognosis. As a result, numerous biomarkers have been investigated in an effort to identify and prevent certain diseases sooner. We looked at both established biomarkers, such as NT-proBNP, hs-troponins, and pro-inflammatory cytokines, and newer ones, such as extracellular vesicles (EVs), donor specific antibodies (DSA), gene expression profile (GEP), donor-derived cell free DNA (dd-cfDNA), microRNA (miRNA), and soluble suppression of tumorigenicity 2 (sST2). These biomarkers are typically linked to complications from HTX. We also highlight the relationships between each biomarker and one or more problems, as well as their applicability in routine clinical practice

    PrĂ€ferenz fĂŒr Intuition und Deliberation – Messung und Konsequenzen von affekt- und kognitionsbasiertem Entscheiden

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    Personen unterscheiden sich darin, ob sie bevorzugt intuitiv oder reflektiv entscheiden (Epstein et al., 1996). Um diese individuellen Unterschiede zu erfassen, wurde ein neues Fragebogenmaß konstruiert, das die PrĂ€ferenz fĂŒr Intuition und Deliberation (PID, Betsch, 2004) auf zwei unabhĂ€ngigen Skalen misst (PrĂ€ferenz fĂŒr Intuition und PrĂ€ferenz fĂŒr Deliberation). Intuition wird hier als ein rein affektiver Modus verstanden. Deliberation ist konzipiert als reflektiver, kognitionsbasierter Modus. In drei Studien wird die Konstruktion, ÜberprĂŒfung der ZweidimensionalitĂ€t und Validierung der Skala anhand von insgesamt ĂŒber 2500 Versuchspersonen berichtet (Betsch, 2004). PrĂ€ferenz fĂŒr Intuition korreliert positiv mit schnellem Entscheiden, Extraversion und VertrĂ€glichkeit und ist unabhĂ€ngig von der FĂ€higkeit zu logischem Denken. PrĂ€ferenz fĂŒr Deliberation korreliert mit Gewissenhaftigkeit, Perfektionismus, BedĂŒrfnis nach Strukturiertheit und ist ebenfalls unabhĂ€ngig von logischem Denken. Die ValiditĂ€t der Skala und die Implikationen fĂŒr die Entscheidungsforschung werden in einer weiteren Studie ĂŒberprĂŒft, die die KrĂŒmmung der Nutzenfunktion mit der individuellen PrĂ€ferenz fĂŒr Intuition und Deliberation in Verbindung setzt (Schunk & Betsch, im Druck). Die Ergebnisse der Studie zeigen, dass die Entscheidungen intuitiver Menschen das GefĂŒhl, das durch erlebtes Risiko evoziert wurde, integrieren, wĂ€hrend dies bei deliberaten Personen nicht der Fall ist. Dies fĂŒhrt zu unterschiedlich gekrĂŒmmten Nutzenfunktionen. Neben den Haupteffekten der StrategieprĂ€ferenzen werden auch die Interaktion zwischen der individuell bevorzugten und der tatsĂ€chlich angewandten Strategie in fĂŒnf Studien untersucht (Betsch & Kunz, zur Veröffentlichung eingereicht). Die Ergebnisse der Studien zeigen, dass die Passung zwischen der bevorzugten und tatsĂ€chlich verwendeten Strategie (sogenannter decisional fit) den wahrgenommenen Wert des gewĂ€hlten oder evaluierten Objektes erhöht und dass die Passung als Schutzschild dient gegenĂŒber negativen Emotionen (z.B. Bedauern) nach Entscheidungen mit schlechtem Ausgang. Zusammenfassend umfasst diese Dissertation die Konstruktion und Validierung der Skala zur Erfassung der individuellen PrĂ€ferenz fĂŒr Intuition und Deliberation (PID; Betsch, 2004). Weiterhin untersucht sie die Konsequenzen von individuellen Unterschieden in affekt- vs. kognitionsbasiertem Entscheiden auf einen basalen Entscheidungsparameter (die Nutzenfunktion, Schunk & Betsch, im Druck). Außerdem zeigen weitere Studien die Konsequenzen einer Person x Situation Interaktion fĂŒr zentrale Variablen der Entscheidungsliteratur auf (Wert, Bedauern; Betsch & Kunz, zur Veröffentlichung eingereicht)

    Attaching DNA to Nanoceria: Regulating Oxidase Activity and Fluorescence Quenching

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    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Applied Materials and Interfaces copyright © American Chemical Society after peer review and technical editing by publisher. To access the final edited and published work see Pautler, R., Kelly, E. Y., Huang, P.-J. J., Cao, J., Liu, B., & Liu, J. (2013). Attaching DNA to Nanoceria: Regulating Oxidase Activity and Fluorescence Quenching. ACS Applied Materials & Interfaces, 5(15), 6820–6825. https://doi.org/10.1021/am4018863Cerium oxide nanoparticles (nanoceria) have recently emerged as a nanozyme with oxidase activity. In this work, we present a few important interfacial properties of nanoceria. First, the surface charge of nanoceria can be controlled not only by adjusting pH but also by adsorption of simple inorganic anions. Adsorption of phosphate and citrate gives negatively charged surface over a broad pH range. Second, nanoceria adsorbs DNA via the DNA phosphate backbone in a sequence-independent manner; DNA adsorption inhibits its oxidase activity. Other anionic polymers display much weaker inhibition effects. Adsorption of simple inorganic phosphate does not have the inhibition effect. Third, nanoceria is a quencher for many fluorophores. These discoveries provide an important understanding for further use of nanoceria in biosensor development, materials science, and nanotechnology.University of Waterloo || Canadian Foundation for Innovation || Natural Sciences and Engineering Research Council || Ontario Ministry of Research and Innovation |

    Cerium Oxide Nanoparticles Protect Cardiac Progenitor Cells from Oxidative Stress

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    Cardiac progenitor cells (CPCs) are a promising autologous source of cells for cardiac regenerative medicine. However, CPC culture in vitro requires the presence of microenvironmental conditions (a complex array of bioactive substance concentration, mechanostructural factors, and physicochemical factors) closely mimicking the natural cell surrounding in vivo, including the capability to uphold reactive oxygen species (ROS) within physiological levels in vitro. Cerium oxide nanoparticles (nanoceria) are redox-active and could represent a potent tool to control the oxidative stress in isolated CPCs. Here, we report that 24 h exposure to 5, 10, and 50 !g/mL of nanoceria did not a!ect cell growth and function in cardiac progenitor cells, while being able to protect CPCs from H2O2-induced cytotoxicity for at least 7 days, indicating that nanoceria in an e!ective antioxidant. Therefore, these "ndings con"rm the great potential of nanoceria for controlling ROS-induced cell damage

    A physical map for the Amborella trichopoda genome sheds light on the evolution of angiosperm genome structure

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    Background: Recent phylogenetic analyses have identified Amborella trichopoda, an understory tree species endemic to the forests of New Caledonia, as sister to a clade including all other known flowering plant species. The Amborella genome is a unique reference for understanding the evolution of angiosperm genomes because it can serve as an outgroup to root comparative analyses. A physical map, BAC end sequences and sample shotgun sequences provide a first view of the 870 Mbp Amborella genome.Results: Analysis of Amborella BAC ends sequenced from each contig suggests that the density of long terminal repeat retrotransposons is negatively correlated with that of protein coding genes. Syntenic, presumably ancestral, gene blocks were identified in comparisons of the Amborella BAC contigs and the sequenced Arabidopsis thaliana, Populus trichocarpa, Vitis vinifera and Oryza sativa genomes. Parsimony mapping of the loss of synteny corroborates previous analyses suggesting that the rate of structural change has been more rapid on lineages leading to Arabidopsis and Oryza compared with lineages leading to Populus and Vitis. The gamma paleohexiploidy event identified in the Arabidopsis, Populus and Vitis genomes is shown to have occurred after the divergence of all other known angiosperms from the lineage leading to Amborella.Conclusions: When placed in the context of a physical map, BAC end sequences representing just 5.4% of the Amborella genome have facilitated reconstruction of gene blocks that existed in the last common ancestor of all flowering plants. The Amborella genome is an invaluable reference for inferences concerning the ancestral angiosperm and subsequent genome evolution

    The Allelic Landscape of Human Blood Cell Trait Variation and Links to Common Complex Disease

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    Many common variants have been associated with hematological traits, but identification of causal genes and pathways has proven challenging. We performed a genome-wide association analysis in the UK Biobank and INTERVAL studies, testing 29.5 million genetic variants for association with 36 red cell, white cell, and platelet properties in 173,480 European-ancestry participants. This effort yielded hundreds of low frequency (<5%) and rare (<1%) variants with a strong impact on blood cell phenotypes. Our data highlight general properties of the allelic architecture of complex traits, including the proportion of the heritable component of each blood trait explained by the polygenic signal across different genome regulatory domains. Finally, through Mendelian randomization, we provide evidence of shared genetic pathways linking blood cell indices with complex pathologies, including autoimmune diseases, schizophrenia, and coronary heart disease and evidence suggesting previously reported population associations between blood cell indices and cardiovascular disease may be non-causal.We thank members of the Cambridge BioResource Scientific Advisory Board and Management Committee for their support of our study and the National Institute for Health Research Cambridge Biomedical Research Centre for funding. K.D. is funded as a HSST trainee by NHS Health Education England. M.F. is funded from the BLUEPRINT Grant Code HEALTH-F5-2011-282510 and the BHF Cambridge Centre of Excellence [RE/13/6/30180]. J.R.S. is funded by a MRC CASE Industrial studentship, co-funded by Pfizer. J.D. is a British Heart Foundation Professor, European Research Council Senior Investigator, and National Institute for Health Research (NIHR) Senior Investigator. S.M., S.T, M.H, K.M. and L.D. are supported by the NIHR BioResource-Rare Diseases, which is funded by NIHR. Research in the Ouwehand laboratory is supported by program grants from the NIHR to W.H.O., the European Commission (HEALTH-F2-2012-279233), the British Heart Foundation (BHF) to W.J.A. and D.R. under numbers RP-PG-0310-1002 and RG/09/12/28096 and Bristol Myers-Squibb; the laboratory also receives funding from NHSBT. W.H.O is a NIHR Senior Investigator. The INTERVAL academic coordinating centre receives core support from the UK Medical Research Council (G0800270), the BHF (SP/09/002), the NIHR and Cambridge Biomedical Research Centre, as well as grants from the European Research Council (268834), the European Commission Framework Programme 7 (HEALTH-F2-2012-279233), Merck and Pfizer. DJR and DA were supported by the NIHR Programme ‘Erythropoiesis in Health and Disease’ (Ref. NIHR-RP-PG-0310-1004). N.S. is supported by the Wellcome Trust (Grant Codes WT098051 and WT091310), the EU FP7 (EPIGENESYS Grant Code 257082 and BLUEPRINT Grant Code HEALTH-F5-2011-282510). The INTERVAL study is funded by NHSBT and has been supported by the NIHR-BTRU in Donor Health and Genomics at the University of Cambridge in partnership with NHSBT. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR, the Department of Health of England or NHSBT. D.G. is supported by a “la Caixa”-Severo Ochoa pre-doctoral fellowship
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