Lithium-sulfur batteries have attracted worldwide interest due to their high theoretical capacity of 1672 mAh g and low cost. However, the practical applications are hampered by capacity decay, mainly attributed to the polysulfide shuttle. Here, the authors have fabricated a solid core-shell γ-MnO -coated sulfur nanocomposite through the redox reaction between KMnO and MnSO . The multifunctional MnO shell facilitates electron and Li transport as well as efficiently prevents polysulfide dissolution via physical confinement and chemical interaction. Moreover, the γ-MnO crystallographic form also provides one-dimensional (1D) tunnels for the Li incorporation to alleviate insoluble Li S /Li S deposition at high discharge rate. More importantly, the MnO phase transformation to Mn O occurs during the redox reaction between polysulfides and γ-MnO is first thoroughly investigated. The S@γ-MnO composite exhibits a good capacity retention of 82% after 300 cycles (0.5 C) and a fade rate of 0.07% per cycle over 600 cycles (1 C). The degradation mechanism can probably be elucidated that the decomposition of the surface Mn O phase is the cause of polysulfide dissolution. The recent work thus sheds new light on the hitherto unknown surface interaction mechanism and the degradation mechanism of Li-S cells.

Background/Aims: The elucidation of the molecular mechanism of adipocyte differentiation in mesenchymal stem cells is of essential importance for the development of treatments for metabolic diseases, such as obesity and diabetes. Methods: The expression levels of miR-342-3p and carboxy-terminal binding protein 2 (CtBP2) were regulated by oligonucleotide transfection. Adipogenic differentiation was induced by adipogenic medium containing indomethacin, dexamethasone and 3-isobutyl-1-methylxanthine on day 12, as determined by Oil Red O staining and triglyceride concentration assay to assess intracellular lipid accumulation. The induction of adipocyte-specific transcription factors and markers was detected by qRT-PCR and western blot. The regulation of CtBP2 expression by miR-342-3p was determined by western blot, qRT-PCR, luciferase reporter assay, ChIP assay and functional experiments. Results: We revealed that miR-342-3p was enriched in the adipose tissue of obese mice, and its expression was significantly elevated during adipogenic differentiation in both human mesenchymal stem cells (hMSCs) and 3T3L1 cells. Using gain- and loss-of-function assays, we demonstrated that the overexpression of miR-342-3p markedly promoted the differentiation of hMSCs into an adipogenic lineage. Adipogenesis was significantly blocked by miR-342-3p downregulation. We identified and validated that CtBP2 was a direct target of miR-342-3p in this process. The effects of the inhibition of CtBP2 were similar to those of miR-342-5p overexpression on adipogenic differentiation, promoting the release of C/EBPα from CtBP2 binding. Conclusion: miR-342-3p is a powerful enhancer of the adipogenesis of human adipose-derived MSCs that acts by inhibiting CtBP2 and releasing the key adipogenic regulator C/EBPα from CtBP2 binding, subsequently activating the expression of adipogenic transcription factors and markers.

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The control over self-assembly behavior becomes absolutely critical because it is dependent on the orientation and morphology. The motivation is focused on borrowing the help of O-H···O hydrogen bonding interactions to realize the control in chiral self-assembly. A series of perylene bisimide (PBI) dyes 3a-3d bearing chiral amino acid derivatives on the imide N atoms and four phenoxy-type substituents at the bay positions of the perylene core were synthesized. Optical properties and aggregation behavior of PBIs were investigated by absorption, fluorescence, circular dichroism (CD), and (1)H NMR spectroscopy. Except for the chiral ester 3c and achiral 3d, chiral dyes 3a and 3b show bisignated CD signals, indicating that the chiral carboxylic acid-functionalized PBI systems are found to be spontaneously self-assembled into supramolecular helices via intermolecular hydrogen bonding rather than π-π stacking. Furthermore, the chirality-controlled helical superstructures are strongly dependent on several factors, such as solvent polarity, concentration, and temperature. The supramolecular helical chirality can be well-controlled by the chiral amino acid residues in the PBI system; that is, the assembled clockwise (plus, P) or anticlockwise (minus, M) helices can be induced by L- or D-isomers, respectively.

Titanium dioxide nanoparticles (TiO2 NPs) were used worldwide for decades, and pregnant women are unable to avoid exposing to them. Studies revealed that TiO2 NPs could kill many kinds of bacteria, but whether they would affect the composition of gut microbiota, especially during pregnancy, was seldom reported. And, what adverse effects may be brought to pregnant females was also unknown. In this study, we established the prenatal exposure model of rats to explore the effects of TiO2 NPs on gut microbiota. We observed an increasing trend, but not a significant change of alpha-diversity among control and exposure groups at gestation day (GD) 10 and GD 17 during normal pregnancy process. Each different time point had unique gut microbiota operational taxonomic units (OTUs) characteristics. The abundance of Ellin6075 decreased at GD 10 and GD 17, Clostridiales increased at GD 10, and Dehalobacteriaceae decreased at GD 17 after TiO2 NPs exposure. Further phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) prediction indicated that the type 2 diabetes mellitus related genes were enhanced, and taurine metabolism was weakened at the second-trimester. Further study showed that the rats’ fasting blood glucose levels significantly increased at GD 10 (P < 0.05) and GD 17 (P < 0.01) after exposure. Our study pointed out that TiO2 NPs induced the alteration of gut microbiota during pregnancy and increased the fasting blood glucose of pregnant rats, which might increase the potential risk of gestational diabetes of pregnant women.