Stabilizing the Oxygen Lattice and Reversible Oxygen Redox Chemistry through Structural Dimensionality in Lithium-Rich Cathode Oxides.

Lattice-oxygen redox (l-OR) has become an essential companion to the traditional transition-metal (TM) redox charge compensation to achieve high capacity in Li-rich cathode oxides. However, the understanding of l-OR chemistry remains elusive, and a critical question is the structural effect on the stability of l-OR reactions. Herein, the coupling between l-OR and structure dimensionality is studied. We reveal that the evolution of the oxygen-lattice structure upon l-OR in Li-rich TM oxides which have a three-dimensional (3D)-disordered cation framework is relatively stable, which is in direct contrast to the clearly distorted oxygen-lattice framework in Li-rich oxides which have a two-dimensional (2D)/3D-ordered cation structure. Our results highlight the role of structure dimensionality in stabilizing the oxygen lattice in reversible l-OR, which broadens the horizon for designing high-energy-density Li-rich cathode oxides with stable l-OR chemistry

Polyphyllin VII alleviates pulmonary hypertension by inducing miR-205–5p to target the β-catenin pathway

Objective: This study aims to investigate the impact of Polyphyllin VII (PP7) on pulmonary hypertension (PH) and elucidate the underlying mechanism involving microRNA (miR)−205–5p/β-catenin. Methods: The PH rat model was induced through hypoxia exposure. The effects of intraperitoneal injection of PP7 on pulmonary artery tissue pathology, hemodynamics, miR-205–5p expression and β-catenin protein levels were assessed. In vitro, pulmonary arterial smooth muscle cells (PASMCs) were subjected to hypoxic conditions. Moreover, miR-205–5p and/or β-catenin were overexpressed through transfection. PASMCs were pre-cultured in 20 μM PP7, and subsequent measurements included proliferation, apoptosis and vascular remodeling protein expression. Results: PP7 ameliorated PH symptoms in rats, upregulated miR-205–5p expression and inhibited β-catenin protein expression. Furthermore, miR-205–5p upregulation inhibited β-catenin expression in PASMCs. The overexpression of β-catenin aggravated hypoxia-induced proliferation, inhibited apoptosis and further augmented VEGF and α-SMA protein expression. Additionally, miR-205–5p overexpression alleviated the hypoxia-induced PASMC proliferation and apoptosis by inhibiting β-catenin protein expression. Under hypoxic conditions, PP7 significantly elevated miR-205–5p while downregulating β-catenin protein expression. Furthermore, inhibiting miR-205–5p counteracted the inhibitory effect of PP7 on β-catenin, consequently blocking the regulatory role of PP7 in PASMC proliferation and apoptosis. Conclusion: PP7 likely modulates β-catenin protein levels by promoting miR-205–5p expression, thereby alleviating PH, vascular remodeling and airway smooth muscle remodeling

Phthalocyanine-Triggered Helical Dipeptide Nanotubes with Intense Circularly Polarized Luminescence

Nanotubes with circularly polarized luminescence (CPL) are attracting much attention due to many potential applications, such as chiroptical materials, displays, and sensing. However, it remains a challenge to change the assemblies of ordinarily molecular building blocks into CPL supramolecular nanotubes. Herein, the regulation of quite common dipeptide (Fmoc-FF) assemblies into unprecedented helical nanotubes exhibiting intense CPL is reported by simply doping a few phthalocyanine (octakis(carboxyl)phthalocyaninato zinc complex (Pc)) molecules. Interestingly, altering the Fmoc-FF/Pc molar ratios over a wide range cannot change the nanotubes structures according to transmission electron microscopy (TEM) and atomic force microscope (AFM) measurements. Although molecular dynamics simulations suggest that the noncovalent interactions between Fmoc-FF and Pc are quite weak, few Pc molecules can still change the secondary structures of a large number of Fmoc-FF assemblies, which hierarchically form helical supramolecular nanotubes with long-range ordered molecular packing, leading to intense CPL signals with large luminescence dissymmetry factor (g(lum) = 0.04). Consequently, the chiral reorganization of Fmoc-FF assemblies is dependent on the coassembly between Pc molecule and Fmoc-FF supramolecular architectures. These results open the possibility for the fine-tuning of helix and supramolecular nanotubes with CPL properties by using a small number of cofactors

Building aqueous K-ion batteries for energy storage

Aqueous K-ion batteries (AKIBs) are promising candidates for grid-scale energy storage due to their inherent safety and low cost. However, full AKIBs have not yet been reported due to the limited availability of suitable electrodes and electrolytes. Here we propose an AKIB system consisting of an Fe-substituted Mn-rich Prussian blue KxFeyMn1-y[Fe(CN)(6)](w)center dot zH(2)O cathode, an organic 3,4,9,10-perylenetetracarboxylic diimide anode and a 22 M KCF3SO3 water-in-salt electrolyte. The cathode achieves 70% capacity retention at 100 C and a lifespan of over 10,000 cycles due to the mitigation of phase transitions by Fe substitution. Meanwhile, the electrolyte can help decrease the dissolution of both electrodes owing to the lack of free water. The AKIB exhibits a high energy density of 80 Wh kg(-1) and can operate well at rates of 0.1-20 C and over a wide temperature range (-20 to 60 degrees C). We believe that our demonstration could pave the way for practical applications of AKIBs for grid-scale energy storage.</p

Enhancement of Tendon Repair Using Tendon-Derived Stem Cells in Small Intestinal Submucosa via M2 Macrophage Polarization

(1) Background: Reconstruction of Achilles tendon defects and prevention of postoperative tendon adhesions were two serious clinical problems. In the treatment of Achilles tendon defects, decellularized matrix materials and mesenchymal stem cells (MSCs) were thought to address both problems. (2) Methods: In vitro, cell adhesion, proliferation, and tenogenic differentiation of tendon-derived stem cells (TDSCs) on small intestinal submucosa (SIS) were evaluated. RAW264.7 was induced by culture medium of TDSCs and TDSCs–SIS scaffold groups. A rat Achilles tendon defect model was used to assess effects on tendon regeneration and antiadhesion in vivo. (3) Results: SIS scaffold facilitated cell adhesion and tenogenic differentiation of TDSCs, while SIS hydrogel coating promoted proliferation of TDSCs. The expression of TGF-β and ARG-1 in the TDSCs-SIS scaffold group were higher than that in the TDSCs group on day 3 and 7. In vivo, the tendon regeneration and antiadhesion capacity of the implanted TDSCs–SIS scaffold was significantly enhanced. The expression of CD163 was significantly highest in the TDSCs–SIS scaffold group; meanwhile, the expression of CD68 decreased more significantly in the TDSCs–SIS scaffold group than the other two groups. (4) Conclusion: This study showed that biologically prepared SIS scaffolds synergistically promote tendon regeneration with TDSCs and achieve antiadhesion through M2 polarization of macrophages