Lithium-ion batteries (LIBs) are common in everyday life
and the
demand for their raw materials is increasing. Additionally, spent
LIBs should be recycled to achieve a circular economy and supply resources
for new LIBs or other products. Especially the recycling of the active
material of the electrodes is the focus of current research. Existing
approaches for recycling (e.g., pyro-, hydrometallurgy, or flotation)
still have their drawbacks, such as the loss of materials, generation
of waste, or lack of selectivity. In this study, we test the behavior
of commercially available LiFePO4 and two types of graphite
microparticles in a dielectrophoretic high-throughput filter. Dielectrophoresis
is a volume-dependent electrokinetic force that is commonly used in
microfluidics but recently also for applications that focus on enhanced
throughput. In our study, graphite particles show significantly higher
trapping than LiFePO4 particles. The results indicate that
nearly pure fractions of LiFePO4 can be obtained with this
technique from a mixture with graphite.
Efavirenz is a widely prescribed non-nucleoside reverse transcriptase inhibitor for the treatment of HIV infections. To test for potential long-term consequences of efavirenz on brain cells, cultured primary astrocytes were incubated with this substance or with its primary metabolite 8-hydroxy efavirenz for up to 7 days. Both, efavirenz and 8-hydroxy efavirenz caused time- and concentration-dependent cell toxicity and stimulated in subtoxic concentrations the glycolytic flux (glucose consumption and lactate release) in astrocytes. As 8-hydroxy efavirenz was less toxic than efavirenz and stimulated glycolysis in lower concentrations we tested for a potential hydroxylation of efavirenz to 8-hydroxy efavirenz in astrocytes. Analysis of media and cell lysates by HPLC-UV and mass spectrometry revealed that after 3 days of incubation viable astrocytes had accumulated about 17 and 7 % of the applied efavirenz and 8-hydroxy efavirenz, respectively. However, in cultures treated with efavirenz neither 8-hydroxy efavirenz nor any other known metabolite of efavirenz was detectable. These data demonstrate that cultured rat astrocytes efficiently accumulate, but not metabolize, efavirenz and 8-hydroxy efavirenz and that the observed chronic stimulation of glycolysis is mediated by both efavirenz and 8-hydroxy efavirenz.
Many interesting applications of magnetic iron oxide nanoparticles (IONPs) have recently been developed based on their magnetic properties and promising catalytic activity. Depending on their intended use, such nanoparticles (NPs) are frequently functionalized with proteins, polymers, or other organic molecules such as meso-2,3-dimercaptosuccinic acid (DMSA) to improve their colloidal stability or biocompatibility.Although the coating strongly affects the colloidal properties and environmental behaviour of NPs, quantitative analysis of the coating is often neglected. To address this issue, we established an ion chromatographic method for the quantitative analysis of surface-bound sulfur-containing molecules such as DMSA. The method determines the amount of sulfate generated by complete oxidation of sulfur present in the molecule. Quantification of the DMSA content of DMSA-coated IONPs showed that reproducibly approximately 38% of the DMSA used in the synthesis was adsorbed on the IONPs. Tests for the biodegradability of free and NP-bound DMSA using a microbial community from a wastewater treatment plant showed that both free and NP-bound DMSA was degraded to negligible extent, suggesting long-term environmental stability of DMSA-coated IONPs.
The data provided by the spectrometer was acquired by a Labview program every 250 ms and stored in a text file. The files were then processed using a MATLAB script, which is published in an online repository along with the measurement data. 1 First, the background intensity i b is determined and subtracted from the signal (see below). Second, the data was summed over several wavelengths (here, from 400 nm to
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