The radionuclide thorium-229 features an isomer with an exceptionally low excitation energy that enables direct laser manipulation of nuclear states. It constitutes one of the leading candidates for ...use in next-generation optical clocks1-3. This nuclear clock will be a unique tool for precise tests of fundamental physics4-9. Whereas indirect experimental evidence for the existence of such an extraordinary nuclear state is substantially older10, the proof of existence has been delivered only recently by observing the isomer's electron conversion decay11. The isomer's excitation energy, nuclear spin and electromagnetic moments, the electron conversion lifetime and a refined energy of the isomer have been measured12-16. In spite of recent progress, the isomer's radiative decay, a key ingredient for the development of a nuclear clock, remained unobserved. Here, we report the detection ofthe radiative decay of this low-energy isomer in thorium-229 (229mTh). By performing vacuum-ultraviolet spectroscopy of 229mTh incorporated into large-bandgap CaF2 and MgF2 crystals at the ISOLDE facility at CERN, photons of8.338(24) eV are measured, in agreement with recent measurements14-16 and the uncertainty is decreased by a factor of seven. The half-life of 229mTh embedded in MgF2 is determined to be 670(102) s. The observation of the radiative decay in a large-bandgap crystal has important consequences for the design of a future nuclear clock and the improved uncertainty of the energy eases the search for direct laser excitation of the atomic nucleus.
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GEOZS, IJS, IMTLJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK, ZAGLJ
Over the past few decades, natural-origin polysaccharides have received increasing attention across different fields of application, including biomedicine and biotechnology, because of their specific ...physicochemical and biological properties that have afforded the fabrication of a plethora of multifunctional devices for healthcare applications. More recently, marine raw materials from fisheries and aquaculture have emerged as a highly sustainable approach to convert marine biomass into added-value polysaccharides for human benefit. Nowadays, significant efforts have been made to combine such circular bio-based approach with cost-effective and environmentally-friendly technologies that enable the isolation of marine-origin polysaccharides up to the final construction of a biomedical device, thus developing an entirely sustainable pipeline. In this regard, the present review intends to provide an up-to-date outlook on the current green extraction methodologies of marine-origin polysaccharides and their molecular engineering toolbox for designing a multitude of biomaterial platforms for healthcare. Furthermore, we discuss how to foster circular bio-based approaches to pursue the further development of added-value biomedical devices, while preserving the marine ecosystem.
This study compares credit spreads and pricing determinants of securitization vis‐à‐vis covered bonds. Our analysis reveals that although ratings are the most important pricing determinant for ...asset‐backed securities (ABS) and mortgage‐backed securities (MBS) investors place relatively more importance on contractual, macroeconomic and banks' characteristics rather than ratings in pricing covered bonds. We find evidence of a mispricing effect in structured finance markets: ABS and MBS have higher credit spreads than similarly rated public‐covered bonds and mortgage‐covered bonds and security prices reflect information beyond credit ratings. We find no evidence of borrowing costs affecting banks' choice between securitization and covered bonds.
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FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
•The durability of a cold-curing structural epoxy adhesive was addressed.•Effects of hygrothermal and outdoor ageing were studied for up to two years.•Media diffusion, and viscoelastic and mechanical ...behaviour were characterised.•The water uptake did not follow a Fickian behaviour.•Both viscoelastic and mechanical behaviour showed irreversible degradation.
This paper presents an experimental study about the durability of a cold curing structural epoxy (EP) adhesive exposed to different hygrothermal and outdoor ageing environments, typical of civil engineering applications, for up to two years: water and salt water immersion at 20 °C and 40 °C, continuous condensation at 40 °C, and outdoor ageing in a mild Mediterranean climate. After specific exposure periods, changes in the following physical properties and mechanical behaviour of the adhesive were assessed: (i) media diffusion, through water uptake (in hygrothermal environments); (ii) viscoelastic behaviour, through dynamic mechanical analyses (DMA); and (iii) flexural and (iv) in plane shear behaviour. Regarding media diffusion, water uptake did not follow a Fickian behaviour and a final saturation stage was not reached; two alternative non-Fickian analytical models were successfully fitted to the test data and the corresponding diffusion parameters were determined. In what concerns the viscoelastic behaviour, while continuous condensation and outdoor ageing caused negligible changes, the Tg of the adhesive generally decreased due to immersion (around 20% in water and 10% in salt water after two years); in addition, at later stages of water immersion, the tanδ curve showed significant shape differences, with the usual curve peak being replaced by two different peaks; a generalised reduction of the storage modulus at the glassy plateau was also noted. In terms of mechanical performance, such plasticization effects were visible in the flexural and shear stress-strain behaviours. The flexural properties exhibited irreversible degradation, with the highest reductions (two years of ageing in water at 40 °C) being about 24% and 30% in strength and modulus, respectively. Regarding the shear properties, in hygrothermal environments the shear modulus showed similar decreasing trends to the flexural modulus (43% reduction after one year), but the shear strength increased (∼25%); the outdoor ageing affected the shear properties in the same way, but the magnitudes of the changes were lower.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Abstract
This work describes an effective method to obtain chiral vinyl cyclopentenols with a high degree of enantioselectivity and diastereoselectivity through Heck desymmetrization of ...cyclopent‐3‐en‐1‐ylmethanol using vinyl triflates as coupling agents and chiral
N,N
ligands. This Heck vinylation protocol allowed the synthesis of several structurally complex cyclopentenols in isolated yields of up to 80 % in enantiomeric ratios of up to 97 : 3 and diastereoselectivities higher than 20 : 1 in most cases. Experiments using (
E
) or (
Z
) vinyl triflates, and desymmetrization of protected olefin 1‐(cyclopent‐3‐en‐1‐ylmethoxy)‐4‐nitrobenzene (
17)
were instrumental in rationalizing the observed diastereoselectivities of Heck products involving the interaction of vinyl triflate carbonyl and the hydroxyl group moiety of the substrate with the cationic Pd(II) complex. The absolute configuration of the vinylated Heck products was determined by Vibrational Circular Dichroism (VCD) spectroscopy.
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BFBNIB, FZAB, GIS, IJS, KILJ, OILJ, SBCE, SBMB, UPUK
Voids have a substantial impact on the mechanical properties of composite laminates and can lead to premature failure of composite parts. Optical microscopy is a commonly employed imaging technique ...to assess the void content of composite parts, as it is reliable and less expensive than alternative options. Usually, image thresholding techniques are used to parse the void content of the acquired microscopy images automatically; however, these techniques are very sensitive to the imaging acquisition conditions and type of composite material used. Additionally, these algorithms have to be calibrated before each analysis, in order to provide accurate results.
This work proposes a machine-learning approach, based on a convolutional neural network architecture, with the objective of providing a robust tool capable of automatically parsing the void content of optical microscopy images, without the need of parameter tuning.
Results from training and testing datasets composed of microscopy images extracted from three distinct types of laminates confirm that the proposed approach parses void content from microscopy images more accurately than a traditional thresholding algorithm, without the need of a previous calibration step. This work shows that the proposed approach is promising, despite sometimes lower than expected precision in individual void statistics.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Antibody-drug conjugates (ADCs) are among the fastest-growing classes of therapeutics in oncology. Although ADCs are in the spotlight, they still present significant engineering challenges. ...Therefore, there is an urgent need to develop more stable and effective ADCs. Most rabbit light chains have an extra disulfide bridge, that links the variable and constant domains, between Cys80 and Cys171, which is not found in the human or mouse. Thus, to develop a new generation of ADCs, we explored the potential of rabbit-derived VL-single-domain antibody scaffolds (sdAbs) to selectively conjugate a payload to Cys80. Hence, a rabbit sdAb library directed towards canine non-Hodgkin lymphoma (cNHL) was subjected to in vitro and in vivo phage display. This allowed the identification of several highly specific VL-sdAbs, including C5, which specifically target cNHL cells in vitro and present promising in vivo tumor uptake. C5 was selected for SN-38 site-selective payload conjugation through its exposed free Cys80 to generate a stable and homogenous C5-DAB-SN-38. C5-DAB-SN-38 exhibited potent cytotoxicity activity against cNHL cells while inhibiting DNA-TopoI activity. Overall, our strategy validates a platform to develop a novel class of ADCs that combines the benefits of rabbit VL-sdAb scaffolds and the canine lymphoma model as a powerful framework for clinically translation of novel therapeutics for cancer.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
In article number 2009619, Tiago R. Correia, João F. Mano, and co‐workers develop a new type of hybrid cells. Individual human adipose‐derived mesenchymal stem cells are partially coated with a hard ...silica layer and display enhanced single‐cell survival and functionality in suspension conditions. Moreover, the ability of functionalizing silica backpacks unlocks the potential application of this novel system in a wide range of applications from biosensing to drug delivery and microtissue formation.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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