Evaluating Polyacrylic Acid as a Universal Aqueous Binder for Ni-Rich Cathodes NMC811 and Si Anodes in Full Cell Lithium-ion Batteries.

Silicon (Si) and silicon/graphite (Si/Gr) composite anodes are promising candidates due to their high theoretical capacity, low operating potential and natural abundance for high energy density Li-ion batteries. Green electrode production, eliminating organic volatile solvents require advancement of aqueous electrodes. Engineering the binder plays a critical role for improving waterborne electrodes. Lithium substituted polyacrylic acid LiPAA has been demonstrated as a promising binder for Si/Gr anodes and for Ni-rich cathodes in different cell configurations. LiPAA is utilized to minimize the volume expansion during cycling for Si/Gr anodes. LiPAA is formed in situ during cathode slurry preparation to regulate the pH and dimmish the Li loss. Using advanced characterization techniques, we investigated the slurries, electrodes, and active material reaction with LiPAA and its effect to the cycling performance. Our results indicate that the performance of high Si containing anode is limited by the amount of Si in the electrode. The failure mechanism with respect to high Si content was studied thoroughly. Aqueous processed cathodes with LiPAA binder in combination with Si anodes outperformed NMP based cathodes. Hence, LiPAA was successfully utilized as an active binder for both a high Si containing anode and for a Ni rich cathode.

Hybrid spheroid microscaffolds as modular tissue units to build macro-tissue assemblies for tissue engineering.

Since its inception, tissue engineering and regenerative medicine (TERM) has been relying on either scaffold-based or scaffold-free strategies. Recent reports outlined the possibility of a synergistic, convergence approach, referred to as the third TERM strategy, which could alleviate bottlenecks of the two previous options. This strategy requires the fabrication of highly porous microscaffolds, allowing to create single spheroids within each of them. The resulting tissue units can then be combined and used as modular building blocks for creating tissue constructs through a bottom-up self-assembly. Such strategy can have a significant impact for the future of TERM, but so far, no reports have assessed its feasibility in detail. This work reports a first systematic study, which includes a comparison of the in vitro behavior of tissue units based on adipose derived stem cell spheroids cultured within microscaffolds versus conventional spheroids. We first proved that the presence of the microscaffold neither impairs the cells 'ability to form spheroids nor impacts their viability. Importantly, the fusiogenic and the differentiation potential (i.e. chondrogenesis and osteogenesis), which are important features for cellularized building blocks to be used in TERM, are preserved when spheroids are cultured within microscaffolds. Significant benefits of microscaffold-based tissue units include the enhanced cell retention, the decreased compaction and the better control over the size observed when larger tissue constructs are formed through self-assembly. The proof of concept study presented here demonstrates the great potential offered by those microsize tissue units to be used as building blocks for directed tissue self-assembly. STATEMENT OF SIGNIFICANCE: One of the most exciting and recent advances in tissue engineering and regenerative medicine (TERM) is to combine together multiple micro-size cellularized units, which are able to self-assemble altogether to recreate larger tissue constructs. In this work, we produce such modules by forming single spheroids within highly porous microscaffolds, and study how this new microenvironment impacts on the spheroid's behavior and stemness potential. This work highlights as well that such novel route is enabled by two-photon polymerization, which is an additive manufacturing technique offering high spatial resolution down to 100 nm. These findings provide a first scientific evidence about the utilization of hybrid spheroid microscaffold-based tissue units with great perspective as a modular tool for TERM.

Assessment of Artificial and Natural Transport Mechanisms of Ice Nucleating Particles in an Alpine Ski Resort in Obergurgl, Austria.

Artificial snow production is a crucial part of modern skiing resorts in Austria and globally, and will develop even more so with changing precipitation patterns and a warming climate trend. Producing artificial snow requires major investments in energy, water, infrastructure and manpower for skiing resorts. In addition to appropriate meteorological conditions, the efficiency of artificial snow production depends on heterogeneous ice-nucleation, which can occur at temperatures as high as -2°C when induced by specific bacterial ice nucleating particles (INPs). We aimed to investigate the presence, source and ice nucleating properties of these particles in the water cycle of an alpine ski resort in Obergurgl, Tyrol, Austria. We sampled artificial snow, river water, water pumped from a storage pond and compared it to samples collected from fresh natural snow and aged piste snow from the area. Particles from each sampled system were characterized in order to determine their transport mechanisms at a ski resort. We applied a physical droplet freezing assay [DRoplet Ice Nuclei Counter Zurich (DRINCZ)] to heated and unheated samples to characterize the biological and non-biological component of IN-activity. Bacterial abundance and community structure of the samples was obtained using quantitative PCR and Illumina Mi-Seq Amplicon Sequencing, and their chemical properties were determined by liquid ion-chromatography, energy dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM). The results show the flow of biological and inorganic material from the river to the slopes, an uptake of new microorganisms through the air and the piping, and possible proliferation or introduction of ice nucleation active biological particles in aged piste snow. Natural snow, as the first stage in this system, had the lowest amount of ice nucleation active particles and the least amount of biological and mineral particles in general, yet shares some microbial characteristics with fresh artificial snow.