The Role for the Endocannabinoid System in Cardioprotection and Myocardial Adaptation

Results from different studies showing CB2 receptor-associated cardioprotective action are still fairly controversial and no single specific mechanism could be identified. Several groups investigated the involvement of the endocannabinoid system in cellular systems and function of cardiomyocytes, fibroblasts, macrophages and endothelial cells. While some studies are limited in their translational relevance, a few recent studies describe a myocardial ischemia and reperfusion scenario in a fashion comparable to the clinical situation. Recent studies provided evidence for involvement of the CB2 receptor–endocannabinoid axis in prevention of cardiomyocyte apoptosis including modulation of antioxidative enzymes and contractile elements expression. CB2 receptor has further been shown to specifically modulate the inflammatory response and macrophage function after myocardial ischemia. These effects have an impact on the subsequent myocardial remodeling, where the CB2 receptor modulates function of myofibroblasts, collagen production and limitation of myocardial infarction size. Recent experimental and clinical data showed the association of the endocannabinoid system in myocardial hypertrophy. In conclusion, increasing amount of evidence supports a crucial role of the endocannabinoid system in cardioprotection and myocardial remodeling, while some of them even suggest model-independent systemic effects in adaptation of cardiomyocytes or components of the extracellular matrix

Mechanochemical synthesis and structure of lithium tetrahaloaluminates, LiAlX₄ (X = Cl, Br, I); a family of Li-ion conducting ternary halides

State-of-the-art oxides and sulfides with high Li-ion conductivity and good electrochemical stability are among the most promising candidates for solid-state electrolytes in secondary batteries. Yet emerging halides offer promising alternatives because of their intrinsic low Li+ migration energy barriers, high electrochemical oxidative stability, and beneficial mechanical properties. Mechanochemical synthesis has enabled the characterization of LiAlX4 compounds to be extended and the iodide, LiAlI4, to be synthesized for the first time (monoclinic P21/c, Z = 4; a = 8.0846(1) Å; b = 7.4369(1) Å; c = 14.8890(2) Å; β = 93.0457(8)°). Of the tetrahaloaluminates, LiAlBr4 exhibited the highest ionic conductivity at room temperature (0.033 mS cm–1), while LiAlCl4 showed a conductivity of 0.17 mS cm–1 at 333 K, coupled with the highest thermal and oxidative stability. Modeling of the diffusion pathways suggests that the Li-ion transport mechanism in each tetrahaloaluminate is closely related and mediated by both halide polarizability and concerted complex anion motions

Solid State Fluorination on the Minute Scale: Synthesis of WO₃₋ₓFx with Photocatalytic Activity

Solid state reactions are notoriously slow, because the rate‐limiting step is diffusion of atoms or ions through reactant, intermediate, and product crystalline phases. This requires days or even weeks of high temperature treatment, consuming large amounts of energy. Metal oxides are particularly difficult to react, because they have high melting points. The study reports a high‐speed solid state fluorination of WO₃ with Teflon to the oxyfluorides WO₃₋ₓFx on a minute (<10 min) scale by spark plasma sintering, a technique that is used typically for a high‐speed consolidation of powders. Automated electron diffraction analysis reveals an orthorhombic ReO₃‐type structure of WO₃₋ₓFx with F atom disorder as demonstrated by ¹⁹F magic angle spinning nuclear magnetic resonance spectroscopy. The potential of this new approach is demonstrated by the following results. i) Mixed‐ valent tungsten oxide fluorides WO₃₋ₓFx with high F content (0 < x < 0.65) are obtained as metastable products in copious amounts within minutes. ii) The spark plasma sintering technique yields WO₃₋ₓFx nanoparticles with high photocatalytic activity, whereas the corresponding bulk phases obtained by conventional solid‐state (ampoule) reactions have no photocatalytic activity. iii) The catalytic activity is caused by the microstructure originating from the processing by spark plasma sintering

Influence of Iron Sulfide Nanoparticle Sizes in Solid‐State Batteries**

Given the inherent performance limitations of intercalationbasedlithium-ion batteries, solid-state conversion batteries arepromising systems for future energy storage. A high specific capacityand natural abundancy make iron disulfide (FeS2) a promisingcathode active material. In this work, FeS2 nanoparticles wereprepared solvothermally. By adjusting the synthesis conditions,samples with average particle diameters between 10 nm and 35 nmwere synthesized. The electrochemical performance was evaluated insolid-state cells with a Li-argyrodite solid electrolyte. While thereduction of FeS2 was found to be irreversible in the initial discharge,a stable cycling of the reduced species was observed subsequently.A positive effect of smaller particle dimensions on FeS2 utilization wasidentified, which can be attributed to a higher interfacial contact areaand shortened diffusion pathways inside the FeS2 particles. Theseresults highlight the general importance of morphological design toexploit the promising theoretical capacity of conversion electrodes insolid-state batteries

Influence of Iron Sulfide Nanoparticle Sizes in Solid‐State Batteries**

Given the inherent performance limitations of intercalation-based lithium-ion batteries, solid-state conversion batteries are promising systems for future energy storage. A high specific capacity and natural abundancy make iron disulfide (FeS2) a promising cathode-active material. In this work, FeS2 nanoparticles were prepared solvothermally. By adjusting the synthesis conditions, samples with average particle diameters between 10 nm and 35 nm were synthesized. The electrochemical performance was evaluated in solid-state cells with a Li-argyrodite solid electrolyte. While the reduction of FeS2 was found to be irreversible in the initial discharge, a stable cycling of the reduced species was observed subsequently. A positive effect of smaller particle dimensions on FeS2 utilization was identified, which can be attributed to a higher interfacial contact area and shortened diffusion pathways inside the FeS2 particles. These results highlight the general importance of morphological design to exploit the promising theoretical capacity of conversion electrodes in solid-state batteries

Cardioprotective Effects of Osteopontin-1 during Development of Murine Ischemic Cardiomyopathy

Repetitive brief ischemia and reperfusion (I/R) is associated with ventricular dysfunction in pathogenesis of murine ischemic cardiomyopathy and human hibernating myocardium. We investigated the role of matricellular protein osteopontin-1 (OPN) in murine model of repetitive I/R. One 15-min LAD-occlusion followed by reperfusion was performed daily over 3, 5, and 7 consecutive days in C57/Bl6 wildtype- (WT-) and OPN−/−-mice (n=8/group). After echocardiography hearts were processed for histological and mRNA-studies. Cardiac fibroblasts were isolated, cultured, and stimulated with TGF-β1. WT-mice showed an early, strong, and cardiomyocyte-specific osteopontin-expression leading to interstitial macrophage infiltration and consecutive fibrosis after 7 days I/R in absence of myocardial infarction. In contrast, OPN−/−-mice showed small, nontransmural infarctions after 3 days I/R associated with significantly worse ventricular dysfunction. OPN−/−-mice had different expression of myocardial contractile elements and antioxidative mediators and a lower expression of chemokines during I/R. OPN−/−-mice showed predominant collagen deposition in macrophage-rich small infarctions. We found lower induction of tenascin-C, MMP-9, MMP-12, and TIMP-1, whereas MMP-13-expression was higher in OPN−/−-mice. Cultured OPN−/−-myofibroblasts confirmed these findings. In conclusion, osteopontin seems to modulate expression of contractile elements, antioxidative mediators, and inflammatory response and subsequently remodel in order to protect cardiomyocytes in murine ischemic cardiomyopathy

Experimental Assessment of the Practical Oxidative Stability of Lithium Thiophosphate Solid Electrolytes

All-solid-state batteries are often expected to replace conventional lithium-ion batteries in the future. However, the practical electrochemical and cycling stability of the best-conducting solid electrolytes, i.e. lithium thiophosphates, are still critical issues that prevent long-term stable high-energy cells. In this study, we use stepwisecyclic voltammetry to obtain information on the practical oxidative stability limit of Li10GeP2S12, a Li2S‑P2S5glass, as well as the argyrodite Li6PS5Cl solid electrolytes. We employ indium metal and carbon black as the counter and working electrode, respectively, the latter to increase the interfacial contact area to the electrolyte as compared to the commonly used planar steel electrodes. Using a stepwise increase in the reversal potentials, the onset potential at 25 °C of oxidative decomposition at the electrode-electrolyte interface is identified. X‑ray photoelectron spectroscopy is used to investigate the oxidation of sulfur(-II) in the thiophosphate polyanions to sulfur(0) as the dominant redox process in all electrolytes tested. Our results suggest that after the formation of these decomposition products, significant redox behavior is observed. This explains previously reported redox activity of thiophosphate solid electrolytes, which contributes to the overall cell performance in solid-state batteries. The stepwise cyclic voltammetryapproach presented here shows that the practical oxidative stability at 25 °C of thiophosphate solid electrolytes against carbon is kinetically higher than predicted by thermodynamic calculations. The method serves as an efficient guideline for the determination of practical, kinetic stability limits of solid electrolytes. </p