644 research outputs found

    Accessing the Next Generation of Synthetic Mussel‐Glue Polymers via Mussel‐Inspired Polymerization

    Get PDF
    The formation of cysteinyldopa as biogenic connectivity in proteins is used to inspire a chemical pathway toward mussel-adhesive mimics. The mussel-inspired polymerization (MIPoly) exploits the chemically diverse family of bisphenol monomers that is oxidizable with 2-iodoxybenzoic acid to give bisquinones. Those react at room temperature with dithiols in Michael-type polyadditions, which leads to polymers with thiol–catechol connectivities (TCC). A set of TCC polymers proved adhesive behavior even on challenging poly(propylene) substrates, where they compete with commercial epoxy resins in dry adhesive strength. MIPoly promises facile scale up and exhibits high modularity to tailor adhesives, as proven on a small library where one candidate showed wet adhesion on aluminum substrates in both water and sea water models.Verband der Chemischen Industrie http://dx.doi.org/10.13039/100007215Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659Peer Reviewe

    Muschelinspirierte Polymerisation

    Get PDF
    Verschiedene marine Lebewesen, wie zum Beispiel Muscheln, zeigen beeindruckende Unterwasserklebefähigkeiten. Vor allem L-3,4-Dihydroxyphenylalanin (Dopa), ein sehr häufig vorkommendes Aminosäurederivat in den Proteinen des Muschelklebesystems, wirkt sich positiv auf die Adhäsions- und Kohäsionsfähigkeit der Muschel aus. Im Rahmen dieser Arbeit dient die Bildung von Cysteinyldopa, welches als biogene Verknüpfung in Proteinen vorkommt, als Inspiration für die Entwicklung eines chemischen Ansatzes zur Synthese muschelmimetischer Klebstoffe. In einem AA+BB-Polyadditionsansatz (muschelinspirierte Polymerisation, MIPoly) werden Dichinone und Dithiole als Monomere eingesetzt. Hierfür werden die Dichinone ausgehend von der chemisch vielfältigen Familie der Bisphenol-Monomere durch Oxidation mit 2-Iodoxybenzoesäure synthetisiert. Die Dichinone und die Dithiole reagieren bei Raumtemperatur in einer Michael-artigen Polyaddition, wodurch Polymeren erhalten werden, die adhäsive Thiol-Catechol-Verknüpfungen (thiol-catechol-connectivities, TCCs) in ihrem Rückgrat aufweisen. Die detaillierte Untersuchung des MIPoly-Prozesses, der gebildeten TCC-Polymere sowie niedermolekularer Modellreaktionen ermöglicht den Nachweis der TCC-Bildung und bestätigte den Michael-artigen-Polyadditionsmechanismus. Dieses chemische MIPoly ist eine robuste Reaktion, die eine einfache Skalierbarkeit verspricht und einen modularen Ansatz für maßgeschneiderte Klebstoffe bietet. Der generische Charakter der untersuchten MIPoly wird durch die Synthese einer TCC-Polymermatrix nachgewiesen. In Klebetests zeigen die synthetisierten TCC-Polymere Hafteigenschaften auf Aluminium und Polypropylen. Darüber hinaus können ausgewählte TCC-Polymere als Unterwasserklebstoffe unter Meerwassermodellbedingungen verwendet werden.Different marine organisms, such as mussels, provide impressive under water gluing capabilities. Mainly L-3,4-dihydroxyphenylalanin (Dopa), which is a highly abundant amino acid derivative in the proteins of the mussel gluing system, was found to have a positive effect on the adhesion and cohesion ability of the mussel. Here, the formation of cysteinyldopa as biogenic connectivity in proteins is used to inspire a chemical pathway toward mussel-adhesive mimics. In an AA+BB polyaddition approach (Mussel-inspired polymerization, MIPoly) bisquinones and dithiols are used as monomers. The bisquinones are synthesized from the chemically diverse family of bisphenol monomers by oxidation with 2-iodoxybenzoic acid. The bisquinones and the dithiols react at room temperature in Michel-type polyaddition, leading to polymers with adhesive thiol-catechol-connectivities (TCCs) in their backbone. The detailed investigation of the MIPoly process, the formed TCC-polymers as well as low molecular model reactions enable the verification of the TCC-formation and confirm the Michael-type polyaddition mechanism. This chemical MIPoly is a robust reaction that promises ease of scale up and provides a modular approach to tailor adhesives. The generic character of the investigated MIPoly process is shown by synthesizing a TCC-polymer matrix. In adhesive tests, the synthesized TCC-polymers show adhesive properties on aluminum and poly(propylene). Furthermore, selected TCC-polymers can be used as underwater adhesives in seawater modeling aqueous environments

    Abdominal obesity‐related disturbance of insulin sensitivity is associated with cd8+ emra cells in the elderly

    Get PDF
    Aging and overweight increase the risk of developing type 2 diabetes mellitus. In this cross‐sectional study, we aimed to investigate the potential mediating role of T‐EMRA cells and inflammatory markers in the development of a decreased insulin sensitivity. A total of 134 healthy older volunteers were recruited (age 59.2 (SD 5.6) years). T cell subpopulations were analyzed by flow cytometry. Furthermore, body composition, HOMA‐IR, plasma tryptophan (Trp) metabolites, as well as cytokines and adipokines were determined. Using subgroup and covariance analyses, the influence of BMI on the parameters was evaluated. Moreover, correlation, multiple regression, and mediation analyses were performed. In the subgroup of participants with obesity, an increased proportion of CD8+EMRA cells and elevated concentrations of plasma kynurenine (KYN) were found compared to the lower‐weight subgroups. Linear regression analysis revealed that an elevated HOMA‐IR could be predicted by a higher proportion of CD8+EMRA cells and KYN levels. A mediation analysis showed a robust indirect effect of the Waist‐to‐hip ratio on HOMA‐IR mediated by CD8+EMRA cells. Thus, the deleterious effects of abdominal obesity on glucose metabolism might be mediated by CD8+EMRA cells in the elderly. Longitudinal studies should validate this assumption and analyze the suitability of CD8+EMRA cells as early predictors of incipient prediabetes. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

    Nanoproteomic analysis of ischemia-dependent changes in signaling protein phosphorylation in colorectal normal and cancer tissue

    Get PDF
    Additional file 1: Table S1. Clinical data for the 20 patients analyzed in the study. Presents patient clinical data including tumor stage and grade

    12-week combined strength and endurance exercise attenuates CD8+ T-cell differentiation and affects the kynurenine pathway in the elderly: a randomized controlled trial

    Get PDF
    Background: Age-related accumulation of highly differentiated CD8+ effector memory re-expressing CD45RA (EMRA) T-cells and disruption of the kynurenine (KYN) pathway are associated with chronic inflammation and the development of insulin resistance. In this study the aim was to investigate the effects of 12-week combined strength and endurance exercise on CD8+ T-cell differentiation and KYN pathway metabolites. Ninety-six elderly subjects (f/m, aged 50—70) were randomized to a control (CON) or exercise (EX) group. The EX group completed combined strength and endurance training twice weekly for one hour each time at an intensity of 60% of the one-repetition maximum for strength exercises and a perceived exertion of 15/20 for endurance exercises. The EX group was also randomly subdivided into two groups with or without a concomitant balanced diet intervention in order to examine additional effects besides exercise alone. Before and after the intervention phase, the proportions of CD8+ T-cell subsets and levels of KYN pathway metabolites in peripheral blood were determined. Results: The CD8+ EMRA T-cell subsets increased in the CON group but remained almost unchanged in the EX group (p =.02). Plasma levels of kynurenic acid (KA) increased in the EX group and decreased in the CON group (p =.03). Concomitant nutritional intervention resulted in lower levels of quinolinic acid (QA) compared with exercise alone (p =.03). Overall, there was a slight increase in the QA/KA ratio in the CON group, whereas it decreased in the EX group (p >.05). Conclusions: Combined strength and endurance training seems to be a suitable approach to attenuate CD8+ T-cell differentiation in the elderly and to redirect the KYN pathway towards KA. The clinical relevance of these effects needs further investigation

    Reliability and suitability of physiological exercise response and recovery markers

    Get PDF
    There is currently insufficient evidence about the reliable quantification of exercise load and athlete’s recovery management for monitoring training processes. Therefore, this test–retest study investigated the reliability of various subjective, muscle force, and blood-based parameters in order to evaluate their suitability for monitoring exercise and recovery cycles. 62 subjects completed two identical 60-min continuous endurance exercise bouts intermitted by a four-week recovery period. Before, immediately after, three, and 24 h after each exercise bout, analysis of parameters were performed. Significant changes over time were found for rating of perceived exertion (RPE), multidimensional mood state questionnaire (MDMQ), maximum voluntary contraction parameters (MVCs), and blood-based biomarkers (p 0.90). A good reliability was found for thiobarbituric acid reactive substances (TBARS) (ICC = 0.79) and haematological markers (ICC = 0.75–0.86). For RPE, MDMQ, interleukin (IL-) 1RA, IL-6, IL-8, IL-15, cortisol, lactate dehydrogenase (LDH), creatine kinase (CK) only moderate reliability was found (ICC < 0.75). Significant associations for IL1-RA and CK to MVC were found. The excellent to moderate reliability of TBARS, LDH, IL-1RA, six measured haematological markers, MVCs and MDMQ implicate their suitability as physiological exercise response and recovery markers for monitoring athletes’ load management. © 2020, The Author(s)

    Modeling plasticity and dysplasia of pancreatic ductal organoids derived from human pluripotent stem cells

    Get PDF
    Personalized in vitro models for dysplasia and carcinogenesis in the pancreas have been constrained by insufficient differentiation of human pluripotent stem cells (hPSCs) into the exocrine pancreatic lineage. Here, we differentiate hPSCs into pancreatic duct-like organoids (PDLOs) with morphological, transcriptional, proteomic, and functional characteristics of human pancreatic ducts, further maturing upon transplantation into mice. PDLOs are generated from hPSCs inducibly expressing oncogenic GNAS, KRAS, or KRAS with genetic covariance of lost CDKN2A and from induced hPSCs derived from a McCune-Albright patient. Each oncogene causes a specific growth, structural, and molecular phenotype in vitro. While transplanted PDLOs with oncogenic KRAS alone form heterogenous dysplastic lesions or cancer, KRAS with CDKN2A loss develop dedifferentiated pancreatic ductal adenocarcinomas. In contrast, transplanted PDLOs with mutant GNAS lead to intraductal papillary mucinous neoplasia-like structures. Conclusively, PDLOs enable in vitro and in vivo studies of pancreatic plasticity, dysplasia, and cancer formation from a genetically defined background

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

    Get PDF
    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

    Get PDF
    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
    corecore