Insights into the Effects of Electrolyte Composition on the Performance and Stability of FeF2 Conversion‐Type Cathodes

As an alternative to commercial Ni‐ and Co‐based intercalation‐type cathode materials, conversion‐type metal fluoride (MF_x) cathodes are attracting more interest due to their promises to increase cell‐level energy density when coupled with lithium (Li) or silicon (Si)‐based anodes. Among metal fluorides, iron fluorides (FeF₂ and FeF₃) are regarded as some of the most promising candidates due to their high capacity, moderately high potential and the very low cost of Fe. In this study, the impacts of electrolyte composition on the performance and stability of nanostructured FeF₂ cathodes are systematically investigated. Dramatic impacts of Li salt composition, Li salt concentration, solvent composition, and cycling potential range on the cathode's most critical performance parameters—stability, capacity, rate, and voltage hysteresis are discovered. In contrast to previous beliefs, it is observed that even if the Fe²⁺ cation dissolution could be avoided, the dissolution of F^? anions may still negatively affect cathode performance. Formation of the more favorable cathode solid electrolyte interface (CEI) is found to minimize both processes.     

Elongation factor eEF1B modulates functions of the release factors eRF1 and eRF3 and the efficiency of translation termination in yeast

Background  

Termination of translation in eukaryotes is controlled by two interacting polypeptide chain release factors, eRF1 and eRF3. While eRF1 recognizes nonsense codons, eRF3 facilitates polypeptide chain release from the ribosome in a GTP-dependent manner. Besides termination, both release factors have essential, but poorly characterized functions outside of translation.     

Prenatal Stress in Maternal Hyperhomocysteinemia: Impairments in the Fetal Nervous System Development and Placental Function

Biochemistry (Moscow) - The article presents current views on maternal hyperhomocysteinemia (HHcy) as an important factor causing prenatal stress and impaired nervous system development in fetuses...     

Neonatal Exposure to Bacterial Lipopolysaccharide Affects Behavior and Expression of Ionotropic Glutamate Receptors in the Hippocampus of Adult Rats after Psychogenic Trauma

Biochemistry (Moscow) - According to the two-hit hypothesis of psychoneuropathology formation, infectious diseases and other pathological conditions occurring during the critical periods of early...     

Nucleus-independent chemical shift criterion for aromaticity in π-extended tetraoxa[8]circulenes

Recently synthesized π-extended symmetrical tetraoxa[8]circulenes that exhibit electroluminescent properties were calculated at the density functional theory (DFT) level using the quantum theory of atoms in molecules (QTAIM) approach to electron density distribution analysis. Nucleus-independent chemical shift (NICS) indices were used to characterize the aromaticity of the studied molecules. The tetraoxa[8]circulene molecules were found to consist of two antiaromatic perimeters (according to the Hückel “4n” antiaromaticity rule) that include 8 and 24 π-electrons. Conversely, NICS calculations demonstrated the existence of a common π-extended system (distributed like a flat ribbon) in the studied tetraoxa[8]circulene molecules. Thus, these symmetrical tetraoxa[8]circulene molecules provide examples of diatropic systems characterized by the presence of induced diatropic ring currents.

Ceruloplasmin: Macromolecular Assemblies with Iron-Containing Acute Phase Proteins

Copper-containing ferroxidase ceruloplasmin (Cp) forms binary and ternary complexes with cationic proteins lactoferrin (Lf) and myeloperoxidase (Mpo) during inflammation. We present an X-ray crystal structure of a 2Cp-Mpo complex at 4.7 Å resolution. This structure allows one to identify major protein–protein interaction areas and provides an explanation for a competitive inhibition of Mpo by Cp and for the activation of p-phenylenediamine oxidation by Mpo. Small angle X-ray scattering was employed to construct low-resolution models of the Cp-Lf complex and, for the first time, of the ternary 2Cp-2Lf-Mpo complex in solution. The SAXS-based model of Cp-Lf supports the predicted 1∶1 stoichiometry of the complex and demonstrates that both lobes of Lf contact domains 1 and 6 of Cp. The 2Cp-2Lf-Mpo SAXS model reveals the absence of interaction between Mpo and Lf in the ternary complex, so Cp can serve as a mediator of protein interactions in complex architecture. Mpo protects antioxidant properties of Cp by isolating its sensitive loop from proteases. The latter is important for incorporation of Fe³⁺ into Lf, which activates ferroxidase activity of Cp and precludes oxidation of Cp substrates. Our models provide the structural basis for possible regulatory role of these complexes in preventing iron-induced oxidative damage.     

Intracellular Neural Recording with Pure Carbon Nanotube Probes

The computational complexity of the brain depends in part on a neuron’s capacity to integrate electrochemical information from vast numbers of synaptic inputs. The measurements of synaptic activity that are crucial for mechanistic understanding of brain function are also challenging, because they require intracellular recording methods to detect and resolve millivolt- scale synaptic potentials. Although glass electrodes are widely used for intracellular recordings, novel electrodes with superior mechanical and electrical properties are desirable, because they could extend intracellular recording methods to challenging environments, including long term recordings in freely behaving animals. Carbon nanotubes (CNTs) can theoretically deliver this advance, but the difficulty of assembling CNTs has limited their application to a coating layer or assembly on a planar substrate, resulting in electrodes that are more suitable for in vivo extracellular recording or extracellular recording from isolated cells. Here we show that a novel, yet remarkably simple, millimeter-long electrode with a sub-micron tip, fabricated from self-entangled pure CNTs can be used to obtain intracellular and extracellular recordings from vertebrate neurons in vitro and in vivo. This fabrication technology provides a new method for assembling intracellular electrodes from CNTs, affording a promising opportunity to harness nanotechnology for neuroscience applications.