The NaxMnO2 materials prepared by a glycine-nitrate method as advanced cathode materials for aqueous sodium-ion rechargeable batteries

Cathodic material for sodium-ion rechargeable batteries based on Na_xMnO₂ were synthesized by glycine nitrate method and subsequent annealing at high temperatures. Different crystal structures with different morphologies were obtained depending on the annealing temperature: hexagonal layeredα-Na_0.7MnO_2.05 nanoplates were obtained at 850 °C, while 3-D tunnel structured Na_0·4MnO₂ and Na_0·44MnO₂, both with rod-like morphology, were obtained at 800 °C and 900 °C, respectively. The investigations of the electrochemical behavior of obtained cathodic materials in aqueous NaNO₃ solution have shown that Na_0·44MnO₂ obtained at 900 °C has shown the best battery performance. Its initial discharge capacities are 123.5 mA h/g, 113.2 mA h/g, and 102.0 mA h/g at the high current densities of 1000, 2000 and 5000 mA/g, respectively.     

Size and Fluorescence Properties of Algal Photosynthetic Antenna Proteins Estimated by Microscopy

Antenna proteins play a major role in the regulation of light-harvesting in photosynthesis. However, less is known about a possible link between their sizes (oligomerization state) and fluorescence intensity (number of photons emitted). Here, we used a microscopy-based method, Fluorescence Correlation Spectroscopy (FCS), to analyze different antenna proteins at the particle level. The direct comparison indicated that Chromera Light Harvesting (CLH) antenna particles (isolated from Chromera velia) behaved as the monomeric Light Harvesting Complex II (LHCII) (from higher plants), in terms of their radius (based on the diffusion time) and fluorescence yields. FCS data thus indicated a monomeric oligomerization state of algal CLH antenna (at our experimental conditions) that was later confirmed also by biochemical experiments. Additionally, our data provide a proof of concept that the FCS method is well suited to measure proteins sizes (oligomerization state) and fluorescence intensities (photon counts) of antenna proteins per single particle (monomers and oligomers). We proved that antenna monomers (CLH and LHCIIm) are more “quenched” than the corresponding trimers. The FCS measurement thus represents a useful experimental approach that allows studying the role of antenna oligomerization in the mechanism of photoprotection.     

Broad Specific Xyloglucan:Xyloglucosyl Transferases Are Formidable Players in the Re-Modelling of Plant Cell Wall Structures

Plant xyloglucan:xyloglucosyl transferases, known as xyloglucan endo-transglycosylases (XETs) are the key players that underlie plant cell wall dynamics and mechanics. These fundamental roles are central for the assembly and modifications of cell walls during embryogenesis, vegetative and reproductive growth, and adaptations to living environments under biotic and abiotic (environmental) stresses. XET enzymes (EC 2.4.1.207) have the β-sandwich architecture and the β-jelly-roll topology, and are classified in the glycoside hydrolase family 16 based on their evolutionary history. XET enzymes catalyse transglycosylation reactions with xyloglucan (XG)-derived and other than XG-derived donors and acceptors, and this poly-specificity originates from the structural plasticity and evolutionary diversification that has evolved through expansion and duplication. In phyletic groups, XETs form the gene families that are differentially expressed in organs and tissues in time- and space-dependent manners, and in response to environmental conditions. Here, we examine higher plant XET enzymes and dissect how their exclusively carbohydrate-linked transglycosylation catalytic function inter-connects complex plant cell wall components. Further, we discuss progress in technologies that advance the knowledge of plant cell walls and how this knowledge defines the roles of XETs. We construe that the broad specificity of the plant XETs underscores their roles in continuous cell wall restructuring and re-modelling.     

Synthetic Polyamine BPA‐C8 Inhibits TGF‐β1‐Mediated Conversion of Human Dermal Fibroblast to Myofibroblasts and Establishment of Galectin‐1‐Rich Extracellular Matrix in Vitro

Cancer‐associated fibroblasts (CAFs) play a role in the progression of malignant tumors. They are formed by conversion of fibroblasts to smooth muscle α‐actin‐positive (SMA‐positive) myofibroblasts. Polyamines are known to change the arrangement of the actin cytoskeleton by binding to the anionic actin. We tested the effect of the synthetic polyamine BPA‐C8 on the transition of human dermal fibroblasts to myofibroblasts induced either by TGF‐β1 alone or by TGF‐β1 together with adhesion/growth‐regulatory galectin‐1. Pre‐existing CAFs, myofibroblasts from pancreatitis, and rat smooth muscle cells were also exposed to BPA‐C8. BPA‐C8 impaired myofibroblast formation from activated fibroblasts, but it had no effect on cells already expressing SMA. BPA‐C8 also reduced the occurrence of an extracellular matrix around the activated fibroblasts. The reported data thus extend current insights into polyamine activity, adding interference with tumor progression to the tumor‐promoting processes warranting study.     

Electrochemical properties of nanostructured Li1.2V3O8 in aqueous LiNO3 solution

The amorphous hydrated precursor of Li_1.2V₃O₈ was synthesized by soft chemistry method, and then heat-treated in air at several temperatures within the range 200–400 °C. The heat-treatment changed its morphological, structural and charging/discharging performance. The product obtained upon the treatment at 300 °C, consisting of uniform, rod-shaped particles, 100–150 nm in diameter and 300–800 nm in length, displayed the best electrochemical performance in aqueous LiNO₃ solution. Its initial discharge capacity amounted to 136.8 mAh g⁻¹ at a rate of C/5, which upon 50 charging/discharging cycles decreased for only 12%.