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Lu Huffman posted an update 1 day, 8 hours ago
A strategy for one-pot and large-scale synthesis of functionalized core-shell nanowires (NWs) to high-efficiently construct single nanowire electrodes is proposed. Based on the polymerization reaction between 3,4-ethylenedioxythiophene (EDOT) and noble metal cations, manifold noble metal nanoparticles-polyEDOT (PEDOT) nanocomposites can be uniformly modified on the surface of any nonconductive NWs. This provides a facile and versatile approach to produce massive number of core-shell NWs with excellent conductivity, adjustable size, and well-designed properties. Nanoelectrodes manufactured with such core-shell NWs exhibit excellent electrochemical performance and mechanical stability as well as favorable antifouling properties, which are demonstrated by in situ intracellular monitoring of biological molecules (nitric oxide) and unraveling its relevant unclear signaling pathway inside single living cells.Hydrogen binding of molecules on solid surfaces is an attractive interaction that can be used as the driving force for bond activation, material-directed assembly, protein protection, etc. However, the lack of a quantitative characterization method for hydrogen bonds (HBs) on surfaces seriously limits its application. Ruboxistaurin We measured the standard Gibbs free energy change (ΔG0 ) of on-surface HBs using NMR. The HB-accepting ability of the surface was investigated by comparing ΔG0 values employing the model biomass platform 5-hydroxymethylfurfural on a series of Co-N-C-n catalysts with adjustable electron-rich nitrogen-doped contents. Decreasing ΔG0 improves the HB-accepting ability of the nitrogen-doped surface and promotes the selectively initiated activation of O-H bonds in the oxidation of 5-hydroxymethylfurfural. As a result, the reaction kinetics is accelerated. In addition to the excellent catalytic performance, the turnover frequency (TOF) for this oxidation is much higher than for reported non-noble-metal catalysts.Photoreceptors are found in all kingdoms of life and bacteriophytochromes (Bphps) are the most abundant photo-sensing receptors in bacteria. Interestingly, BphPs have been linked to some bacterial physiological responses, yet most of the biological processes they regulate are still elusive, especially in non-photosynthetic bacteria. Here, we show that a bacteriophytochrome (CmoBphp) from a deep-sea bacterium Croceicoccus marinus OT19 perceives infrared light (wavelength at 940 nm) and transduces photo-sensing signals to a downstream intracellular transduction cascade for better growth. We discover that the infrared light-mediated growth promotion of C. marinus OT19 is attributed partly to the enhancement of pyruvate and propanoate metabolism. Further study suggests that CmoBphp plays a crucial role in integrating infrared light with intracellular signalling to control the bacterial growth and metabolism. This is the first report that deep-sea non-photosynthetic bacteria can sense infrared light to control growth through a bacteriophytochrome photoreceptor, thus providing new understandings towards light energy utilization by microorganisms.Enzymes catalyzing [4+2] cycloaddition have attracted increasing attention because of their key roles in natural product biosynthesis. Here, we solved the X-ray crystal structures of a pair of decalin synthases, Fsa2 and Phm7, that catalyze intramolecular [4+2] cycloadditions to form enantiomeric decalin scaffolds during biosynthesis of the HIV-1 integrase inhibitor equisetin and its stereochemical opposite, phomasetin. Computational modeling, using molecular dynamics simulations as well as quantum chemical calculations, demonstrates that the reactions proceed through synergetic conformational constraints assuring transition state-like substrates folds and their stabilization by specific protein-substrate interactions. Site-directed mutagenesis experiments verified the binding models. Intriguingly, the flexibility of bound substrates is largely different in two enzymes, suggesting the distinctive mechanism of dynamics regulation behind these stereoselective reactions. The proposed reaction mechanism herein deepens the basic understanding how these enzymes work but also provides a guiding principle to create artificial enzymes.
The aim of this study was to explore correlations between clinical assessor and simulated patient (SP) scores drawn from summative Integrated Structured Clinical Examination (ISCE) and inform the best use of SP scores in future assessments.
This retrospective study explores summative clinical assessor and formative SP numeric scores drawn from summative ISCE assessments spanning three academic years (2017-18 to 2019-20). Analyses were carried out using R 3.5.1 (R Core Team, 2018), with the stats package.
The sample consisted of 169 final-year BDS students across the three cohorts and included 95 females (56.2%) and 74 males (43.8%). Data from eight substations where SPs were included, were explored. Kendall’s Tau, a non-parametric correlation, was used to investigate the relationships between the assessor and SP scores. Clinical assessor scores were out of a total of 20 points across various assessed domains within each substation. The formative SP assessment was out of 10 points with the same five affe information relating to affective skills of students. Notwithstanding the limitations of this study, the findings underscore the need to investigate further the value of involvement of SPs in clinical assessments to explore if scores by SPs can be used to enhance the validity of assessments if used summatively.
The ability to understand figurative language, including metaphors and proverbs, decreases with age, although the phenomenon is not universal. Cognitive capacities and education play an important role in the competence connected with figurative language use and comprehension in people during the second half of life.
To identify possible similarities and differences in task performance by subjects representing middle adulthood (40-49 and 50-59 years old) and late adulthood (60-69 and 70-92 years old). Additionally, the analyses took into account factors significantly affecting the results, that is, tasks type (metaphors versus proverbs), the way the answer is given (open-ended versus multiple choice) and types of answers (abstract and concrete). This study also aimed to identify some cognitive correlates of task completion.
A total of 86 Caucasian subjects, aged 40-92 years, participated in this study (M
= 62.37, SD = 15.53); the group included 20 subjects aged 40-49 years (M
= 45.4; SD = 3.05), 20 aged 50-59 years (M
= 55.