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Short talk Studying the stability and conformational dynamics of the SARS-CoV-2 SL4 RNA hairpin combining base analogues and optical tweezers
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Accelerating Stream Processing Queries with Congestion-aware Scheduling and Real-time Linux Threads
Get PDFStream Processing Engines (SPEs) have been used by companies and industries to develop queries able to extract insights from data streams. The Edge/IoT context poses additional challenges, since streaming queries need to run closer to data producers to save latency, i.e., on resource-constrained devices. Lachesis is a middleware helping Linux to schedule more efficiently threads of the SPE, which revealed useful especially for devices with limited CPU resources. Lachesis does not require any architectural change to the SPE implementation. It collects metrics from the SPE, and computes high-level priorities that are converted into hints to the Operating System to affect its actual scheduling of threads. This paper extends the initial contribution of Lachesis in two main directions: i) we optimize the policy assigning to threads a priority proportional to their actual load by accurately studying the implementation of Storm and Flink, two popular SPEs; ii) instead of restricting the OS scheduling to traditional SCHED_OTHER threads as done previously by Lachesis, we leverage the real-time capability of the modern Linux kernel. Our experimental evaluation shows that both enhancements provide important benefits compared with the previous version of Lachesis: we get +9.75% (average) throughput (+19% peak) with-27% latency on average (-40% peak)
Exploiting Mass Spectrometry to Unlock the Mechanism of Nanoparticle-Induced Inflammasome Activation
Get PDFNanoparticles (NPs) elicit sterile inflammation, but the underlying signaling pathways are poorly understood. Here, we report that human monocytes are particularly vulnerable to amorphous silica NPs, as evidenced by single-cell-based analysis of peripheral blood mononuclear cells using cytometry by time-of-flight (CyToF), while silane modification of the NPs mitigated their toxicity. Using human THP-1 cells as a model, we observed cellular internalization of silica NPs by nanoscale secondary ion mass spectrometry (nanoSIMS) and this was confirmed by transmission electron microscopy. Lipid droplet accumulation was also noted in the exposed cells. Furthermore, time-of-flight secondary ion mass spectrometry (ToF-SIMS) revealed specific changes in plasma membrane lipids, including phosphatidylcholine (PC) in silica NP-exposed cells, and subsequent studies suggested that lysophosphatidylcholine (LPC) acts as a cell autonomous signal for inflammasome activation in the absence of priming with a microbial ligand. Moreover, we found that silica NPs elicited NLRP3 inflammasome activation in monocytes, whereas cell death transpired through a non-apoptotic, lipid peroxidation-dependent mechanism. Together, these data further our understanding of the mechanism of sterile inflammation
Atomically Resolved Interfacial Analysis of Bone-Like Hydroxyapatite Nanoparticles on Titanium
Get PDFTitanium is commonly used for medical devices, including osseointegrating implants, owing to its biocompatibility and mechanical properties. Nanostructuring titanium implants is known to enhance the healing process by promoting bone growth on the implant surface. Hydroxyapatite nanoparticles, resembling natural bone mineral, have been used to further improve osseointegration. While previous studies have investigated the osseointegration of titanium implants using atom probe tomography, limited research has focused on the attachment of synthetic hydroxyapatite to titanium. Herein, electron microscopy and atom probe tomography are used to reveal the assembly of synthetic hydroxyapatite nanoparticles in the titanium oxide surface. By sputter coating with chromium, a suitable matrix is formed for detailed interfacial analysis. The results demonstrate the diffusion of calcium, phosphorus, and carbon from hydroxyapatite nanoparticles into the titanium oxide surface. Titanium is commonly used for medical devices, owing to its biocompatibility and mechanical properties. Nanostructuring titanium implants with hydroxyapatite nanoparticles, resembling natural bone mineral, enhances the healing process by promoting bone growth on the implant surface. Herein, atom probe tomography reveals the assembly of synthetic hydroxyapatite nanoparticles in the titanium oxide surface.image & COPY; 2023 WILEY-VCH Gmb
Holistic pedestrian safety assessment for average males and females
Get PDFObjective: An integrated assessment framework that enables holistic safety evaluations addressing vulnerable road users (VRU) is introduced and applied in the current study. The developed method enables consideration of both active and passive safety measures and distributions of real-world crash scenario parameters. Methods: The likelihood of a specific virtual testing scenario occurring in real life has been derived from accident databases scaled to European level. Based on pre-crash simulations, it is determined how likely it is that scenarios could be avoided by a specific Autonomous Emergency Braking (AEB) system. For the unavoidable cases, probabilities for specific collision scenarios are determined, and the injury risk for these is determined, subsequently, from in-crash simulations with the VIVA+ Human Body Models combined with the created metamodel for an average male and female model. The integrated assessment framework was applied for the holistic assessment of car-related pedestrian protection using a generic car model to assess the safety benefits of a generic AEB system combined with current passive safety structures. Results: In total, 61,914 virtual testing scenarios have been derived from the different car-pedestrian cases based on real-world crash scenario parameters. Considering the occurrence probability of the virtual testing scenarios, by implementing an AEB, a total crash risk reduction of 81.70% was achieved based on pre-crash simulations. It was shown that 50 in-crash simulations per load case are sufficient to create a metamodel for injury prediction. For the in-crash simulations with the generic vehicle, it was also shown that the injury risk can be reduced by implementing an AEB, as compared to the baseline scenarios. Moreover, as seen in the unavoidable cases, the injury risk for the average male and female is the same for brain injuries and femoral shaft fractures. The average male has a higher risk of skull fractures and fractures of more than three ribs compared to the average female. The average female has a higher risk of proximal femoral fractures than the average male. Conclusions: A novel methodology was developed which allows for movement away from the exclusive use of standard-load case assessments, thus helping to bridge the gap between active and passive safety evaluations
Solid solution softening or hardening induced by minor substitutional additions in a Hf20Nb31Ta31Ti18 refractory high entropy alloy
Get PDFThe effect of minor additions of substitutional elements such as Al, Cu, Mn, and Fe on the room-temperature (RT) and elevated-temperature hardness of a single bcc phase Hf20Nb31Ta31Ti18 refractory high entropy alloy is studied here. Interestingly, 2.5 at. % nominal addition of Fe hardened the base Hf20Nb31Ta31Ti18 alloy in the temperature range from RT to 800 \ub0C, while the same nominal content of addition of Al, Cu, and Mn softened the base alloy from RT to 1000 \ub0C. Regardless of solid solution hardening or solid solution softening, the hardness variation with temperature essentially showed the same three-stage pattern for all studied alloys here: a temperature-dependent decrease in hardness below 300 \ub0C/400 \ub0C, followed by a temperature-independent hardness plateau between 300/400 and 800 \ub0C, and finally a temperature-dependent decrease in hardness at temperatures higher than 800 \ub0C. The mechanism for solid solution hardening or softening in bcc-structured refractory high entropy alloys is discussed, together with their temperature dependence
Genesis-DB: a database for autonomous laboratory systems
Get PDFArtificial intelligence (AI)-driven laboratory automation - combining robotic labware and autonomous software agents - is a powerful trend in modern biology. We developed Genesis-DB, a database system designed to support AI-driven autonomous laboratories by providing software agents access to large quantities of structured domain information. In addition, we present a new ontology for modeling data and metadata from autonomously performed yeast microchemostat cultivations in the framework of the Genesis robot scientist system. We show an example of how Genesis-DB enables the research life cycle by modeling yeast gene regulation, guiding future hypotheses generation and design of experiments. Genesis-DB supports AI-driven discovery through automated reasoning and its design is portable, generic, and easily extensible to other AI-driven molecular biology laboratory data and beyond
Catalyst Design for the Valorisation of Biomass-derived Furans into Aromatics
No full textAnno 2023, mankind must strive towards a more sustainable chemical industry; one that does not solely rely on fossil fuels but also utilises renewable feedstocks such as biomass. Biomass can be catalytically converted into commodity chemicals such as aromatics, through intermediates like furans. Aromatics serve as building blocks for everyday materials.In this work, the conversion of one type of furans, 2,5-dimethylfuran, was studied at elevated temperatures in a flow reactor by using a selection of microporous, acidic catalysts. The effluent gas stream was analysed with Fourier-transform infrared spectroscopy and mass spectrometry. Zeolitic catalysts with the MFI-framework were synthesised bottom-up through hydrothermal synthesis, with aluminium or gallium substituted in their framework. Structural analysis was performed comprising X-ray fluorescence, X-ray diffraction, physisorption, thermogravimetric analysis, scanning electron microscopy, and acidity analysis by NH3-TPD.\ua0Both aluminium and gallium-substituted zeolites were active for converting 2,5-dimethylfuran into aromatics, of which Ga-MFI displayed superior benzene production and catalyst lifetime. Catalyst deactivation was caused by the loss of strong and extra-framework acid sites due to the coking. After deactivation towards aromatics, the intermediate products formed on weak acid sites such as 2,4-dimethylfuran, were detected as the main products.It was found that an increase in gallium content increases catalytic activity until a limit of Si/Ga=13 was reached, at which the synthesis of the catalyst also yielded an inactive, amorphous phase. Increasing the crystallisation duration enabled approaching this limit and forming phase-pure MFI zeolite with a Si/Ga ratio of Si/Ga=17. Mesopores were introduced to the catalyst to improve the mass transfer of reactants and products. Even though the total production of aromatics and the catalyst lifetime remained unchanged, its number of acid sites was halved implying that each acid site was able to produce twice as many aromatics
Tribo-corrosion resistance of Ti-Nb-Cr-Mo-Al refractory high-entropy alloys in molten aluminum
No full textTi40Nb25Cr15Mo10Al10 and Ti40Nb20Cr20Mo10Al10 refractory high-entropy alloys (RHEAs) were designed and fabricated, aiming at investigating their mechanical properties, corrosion and tribo-corrosion behavior in molten aluminum. Compared with H13 steel, these RHEAs exhibit significantly better combinations of high-temperature mechanical properties, corrosion and tribo-corrosion resistance. Low solubility of constituent elements in molten aluminum along with slow diffusion of Al atoms in RHEAs’ matrices, are responsible for the outstanding corrosion resistance of RHEAs. Exceptional tribo-corrosion resistance of RHEAs derives from their outstanding combinations of corrosion resistance and high-temperature mechanical properties. Additionally, higher content of Cr in RHEAs would lead to worse tribo-corrosion resistance
Nostalgia, gift, or nice to have – an analysis of unused products in Swedish households
No full textEnsuring the reuse of products once they have fulfilled their purpose at their first owner is one way of extending product lifetimes and a central part of circular economy. In Sweden unused products tend to be retained instead of recirculated, 72% of Swedes use half or less of what is stored in their households (Myrorna, 2018). This paper maps unused yet retained products to understand what causes retention, as well as explores barriers for reuse and the products’ reuse potential. Responses from a diary study (n=45), capturing consumption and divestment behaviour were analysed using thematic analysis. Hassenzahl’s (2003) concept of apparent product character was used as a framework to structure insights regarding unused products in households. Almost all participants retained multiple unused products. Analysis revealed three main types; products retained due to emotional value, products perceived as useful in the future, and products to dispose, consecutively mapping into SELF, ACT, and Unwanted character. Barriers to divestment for products of SELF and ACT character relate to their strong hedonic or pragmatic attributes as products embody memories, social relations, and identity, or a potential future utility. Divestment of these product types require detachment from the product. Products with weak hedonic and pragmatic attributes were also retained, but due to challenging disposition processes. This breadth of unused yet retained products indicates a complex relation between attachment, use, and disposition, where reuse potential varies. The discussion reveals that some product groups are suitable for recirculation outside of the household, while others hold potential for reactivation within the household instead