145 research outputs found
(Electro)catalytic C-C bond formation reaction with a redox-active cobalt complex
Cooperativity between cobalt and non-innocent ligands in electron transfer
processes has been utilized for (electro)catalytic C–C bond formation
reactions
The CIRCULAR pathway: a new educational methodology for exploratory circular value chain redesign
The circular economy (CE) is gaining global relevance across countries and institutions as a tool to solve some of the most pressing global challenges derived from linear production and consumption systems. However, transitioning to a CE requires significant changes in how businesses and supply chains operate, including redesigning products, processes, and business models. These changes require that future professionals acquire knowledge and skills on the principles of CE, Life Cycle Thinking, and Systems Thinking. However, research on existing higher education programs signals a need for educational resources to develop these skills and knowledge in real-world settings. This paper outlines a new eight-step methodology to introduce students to the principles of CE through the exploratory redesign of a real-world product and value chain in a project-centered learning environment. This methodology was developed in four iterations and was used to teach 251 students from the BSc. Business Engineering at Maastricht University during the academic years 2020–2022. The findings indicate that this method supports students' understanding of complexity, linearity, and the importance of systemic change across the entire value chain, as well as their critical thinking, problem-solving, and decision-making skills. The methodology provided in this paper supports and encourages educational bodies to implement Education for CE in their curricula and further strengthens the complementary fields of Education for Environmental Sustainability and Education for Sustainable Development. Furthermore, educators, professionals and businesses can make use of this tested methodology for exploratory product redesign toward sustainable circularity transitions
Probing bistability in FeII and CoII complexes with an unsymmetrically substituted quinonoid ligand
The generation of molecular platforms, the properties of which can be
influenced by a variety of external perturbations, is an important goal in the
field of functional molecular materials. We present here the synthesis of a
new quinonoid ligand platform containing an [O,O,O,N] donor set. The ligand is
derived from a chloranilic acid core by using the [NR] (nitrogen atom with a
substituent R) for [O] isoelectronic substitution. Mononuclear FeII and CoII
complexes have been synthesized with this new ligand. Results obtained from
single crystal X-ray crystallography, NMR spectroscopy,
(spectro)electrochemistry, SQUID magnetometry, multi-frequency EPR
spectroscopy and FIR spectroscopy are used to elucidate the electronic and
geometric structures of the complexes. Furthermore, we show here that the spin
state of the FeII complex can be influenced by temperature, pressure and light
and the CoII complex displays redox-induced spin-state switching. Bistability
is observed in the solid-state as well as in solution for the FeII complex.
The new ligand presented here, owing to the [NR] group present in it, will
likely have more adaptability while investigating switching phenomena compared
to its [O,O,O,O] analogues. Thus, such classes of ligands as well as the
results obtained on the reversible changes in physical properties of the metal
complexes are likely to contribute to the generation of multifunctional
molecular materials
A Prospective Life Cycle Assessment (LCA) of Monomer Synthesis: Comparison of Biocatalytic and Oxidative Chemistry
Biotechnological processes are typically perceived to be greener than chemical processes. A life cycle assessment (LCA) was performed to compare the chemical and biochemical synthesis of lactones obtained by Baeyer-Villiger oxidation. The LCA is prospective (based on experiments at a small scale with primary data) because the process is at an early stage. The results show that the synthesis route has no significant effect on the climate change impact [(1.65 +/- 0.59)kgCO2 g(product)(-1) vs. (1.64 +/- 0.67)kgCO2 g(product)(-1)]. Key process performance metrics affecting the environmental impact were evaluated by performing a sensitivity analysis. Recycling of solvents and enzyme were shown to provide an advantage to the enzymatic synthesis. Additionally, the climate change impact was decreased by 71% if renewable electricity was used. The study shows that comparative LCAs can be used to usefully support decisions at an early stage of process development.</p
Functional investigation of two simultaneous or separately segregating DSP variants within a single family support the theory of a dose-dependent disease severity
Desmoplakin (DP) is an important component of desmosomes, essential in cell-cell connecting structures in stress-bearing tissues. Over many hundreds of pathogenic variants in DSP have been associated with different cutaneous and cardiac phenotypes or a combination, known as a cardiocutaneous syndrome. Of less than 5% of the reported DSP variants, the effect on the protein has been investigated. Here, we describe and have performed RNA, protein and tissue analysis in a large family where DSPc.273+5G>A/c.6687delA segregated with palmoplantar keratoderma (PPK), woolly hair and lethal cardiomyopathy, while DSPWT/c.6687delA segregated with PPK and milder cardiomyopathy. hiPSC-derived cardiomyocytes and primary keratinocytes from carriers were obtained for analysis. Unlike the previously reported nonsense variants in the last exon of DSP that bypassed the nonsense-mediated mRNA surveillance system leading to protein truncation, variant c.6687delA was shown to cause loss of protein expression. Patients carrying both variants and having a considerably more severe phenotype were shown to have 70% DP protein reduction, while patients carrying only c.6687delA had 50% protein reduction and a milder phenotype. Analysis of RNA from patient cells did not show any splicing effect of the c.273+5G>A variant. However, a minigene splicing assay clearly showed alternative spliced transcripts originating from this variant. This study shows the importance of RNA and protein analyses to pinpoint the exact effect of DSP variants instead of solely relying on predictions. In addition, the particular pattern of inheritance, with simultaneous or separately segregating DSP variants within the same family, strongly supports the theory of a dose-dependent disease severity
Developing a Sustainable and Circular Bio-Based Economy in EU:By Partnering Across Sectors, Upscaling and Using New Knowledge Faster, and For the Benefit of Climate, Environment & Biodiversity, and People & Business
This paper gives an overview of development of the EU-bioeconomy, 2014-2020. The Vision of the new Circular Bio-based Economy, CBE is presented: Unlocking the full potential of all types of sustainably sourced biomass, crop residues, industrial side-streams, and wastes by transforming it into value-added products. The resulting product portfolio consists of a wide spectrum of value-added products, addressing societal and consumer needs. Food and feed, bio-based chemicals, materials, healthpromoting products; and bio-based fuels. The pillars of CBE are described, including biotechnology, microbial production, enzyme technology, green chemistry, integrated physical/chemical processing, policies, conducive framework conditions and public private partnerships. Drivers of CBE are analyzed: Biomass supply, biorefineries, value chain clusters, rural development, farmers, foresters and mariners; urgent need for climate change mitigation and adaptation, and stopping biodiversity loss. Improved framework conditions can be drivers but also obstacles if not updated to the era of circularity. Key figures, across the entire BBI-JU project portfolio (20142020) are provided, including expansion into biomass feedstocks, terrestrial and aquatic, and an impressive broadening of bio-based product portfolio, including higher-value, healthpromoting products for man, animal, plants and soil. Parallel to this, diversification of industrial segments and types of funding instruments developed, reflecting industrial needs and academic research involvement. Impact assessment is highlighted. A number of specific recommendations are given; e.g., including international win/win CBEcollaborations, as e.g., expanding African EU collaboration into CBE. In contrast to fossil resources biological resources are found worldwide. In its outset, circular biobased economy, can be implemented all over, in a just manner, not the least stimulating rural developmentThis study received funding only for covering the production costs (carried by the public BBI-JU secretariat).info:eu-repo/semantics/publishedVersio
SARS-Coronavirus Replication Is Supported by a Reticulovesicular Network of Modified Endoplasmic Reticulum
Positive-strand RNA viruses, a large group including human pathogens such as SARS-coronavirus (SARS-CoV), replicate in the cytoplasm of infected host cells. Their replication complexes are commonly associated with modified host cell membranes. Membrane structures supporting viral RNA synthesis range from distinct spherular membrane invaginations to more elaborate webs of packed membranes and vesicles. Generally, their ultrastructure, morphogenesis, and exact role in viral replication remain to be defined. Poorly characterized double-membrane vesicles (DMVs) were previously implicated in SARS-CoV RNA synthesis. We have now applied electron tomography of cryofixed infected cells for the three-dimensional imaging of coronavirus-induced membrane alterations at high resolution. Our analysis defines a unique reticulovesicular network of modified endoplasmic reticulum that integrates convoluted membranes, numerous interconnected DMVs (diameter 200–300 nm), and “vesicle packets” apparently arising from DMV merger. The convoluted membranes were most abundantly immunolabeled for viral replicase subunits. However, double-stranded RNA, presumably revealing the site of viral RNA synthesis, mainly localized to the DMV interior. Since we could not discern a connection between DMV interior and cytosol, our analysis raises several questions about the mechanism of DMV formation and the actual site of SARS-CoV RNA synthesis. Our data document the extensive virus-induced reorganization of host cell membranes into a network that is used to organize viral replication and possibly hide replicating RNA from antiviral defense mechanisms. Together with biochemical studies of the viral enzyme complex, our ultrastructural description of this “replication network” will aid to further dissect the early stages of the coronavirus life cycle and its virus-host interactions
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