Methyl 2-[(4-chloro-2-meth­oxy-5-oxo-2,5-dihydro­furan-3-yl)amino]­acetate

The title compound, C8H10ClNO5, was obtained via a tandem Michael addition–elimination reaction of 3,4-dichloro-5-meth­oxy­furan-2(5H)-one and glycine methyl ester in the presence of triethyl­amine. The mol­ecular structure contains an approximately planar [maximum atomic deviation = 0.010 (2) Å] five-membered furan­one ring. The crystal packing is stabilized by inter­molecular N—H⋯O and weak C—H⋯O hydrogen bonding

Controlled manipulation of oxygen vacancies using nanoscale flexoelectricity

Oxygen vacancies, especially their distribution, are directly coupled to the electromagnetic properties of oxides and related emergent functionalities that have implication in device applications. Here using a homoepitaxial strontium titanate thin film, we demonstrate a controlled manipulation of the oxygen vacancy distribution using the mechanical force from a scanning probe microscope tip. By combining Kelvin probe force microscopy imaging and phase-field simulations, we show that oxygen vacancies can move under a stress-gradient-induced depolarisation field. When tailored, this nanoscale flexoelectric effect enables a controlled spatial modulation. In motion, the scanning probe tip thereby deterministically reconfigures the spatial distribution of vacancies. The ability to locally manipulate oxygen vacancies on-demand provides a tool for the exploration of mesoscale quantum phenomena, and engineering multifunctional oxide devices.Comment: 35 pages, Main text and the supplementary information combine

Enhanced Stem Cell Osteogenic Differentiation by Bioactive Glass Functionalized Graphene Oxide Substrates

An unmet need in engineered bone regeneration is to develop scaffolds capable of manipulating stem cells osteogenesis. Graphene oxide (GO) has been widely used as a biomaterial for various biomedical applications. However, it remains challenging to functionalize GO as ideal platform for specifically directing stem cell osteogenesis. Herein, we report facile functionalization of GO with dopamine and subsequent bioactive glass (BG) to enhance stem cell adhesion, spreading, and osteogenic differentiation. On the basis of graphene, we obtained dopamine functionalized graphene oxide/bioactive glass (DGO/BG) hybrid scaffolds containing different content of DGO by loading BG nanoparticles on graphene oxide surface using sol-gel method. To enhance the dispersion stability and facilitate subsequent nucleation of BG in GO, firstly, dopamine (DA) was used to modify GO. Then, the modified GO was functionalized with bioactive glass (BG) using sol-gel method. The adhesion, spreading, and osteoinductive effects of DGO/BG scaffold on rat bone marrow mesenchymal stem cells (rBMSCs) were evaluated. DGO/BG hybrid scaffolds with different content of DGO could influence rBMSCs’ behavior. The highest expression level of osteogenic markers suggests that the DGO/BG hybrid scaffolds have great potential or elicit desired bone reparative outcome

Suppression of Structural Fatigue by Doping in Spinel Electrode Probed by In Situ Bending Beam Method

The onset of a Jahn-Teller effect at the surface of LiMn2O4 particles during cycling in the 4 V range was previously reported to be one of the causes for the capacity fading. Furthermore, it has been reported that the Jahn-Teller effect in the 4 V range may be suppressed by the substitution of the Mn ions by either Li or other transition metal ions. However, no direct evidence has yet been reported. This study provides evidence for the onset of a Jahn-Teller effect in thin film 4 V LiMn2O4 and its suppression caused by substituting the Mn ions with Co31 and Ni21 ions using in situ bending beam method ~BBM!. The deflectograms are measured simultaneously with galvanostatic charge/discharge or cyclic voltammograms, and the onset of the Jahn-Teller effect is investigated by means of the differential strain peak which is observed at around 3.90-3.95 V during cyclic voltammetry, and the slope variation observed in the strain curves during galvanostatic charge/discharge. The suppression of the Jahn-Teller effect in the doped spinel leads to the magnitude of the differential strain peak resulting from the Jahn-Teller effect being reduced in comparison with the other two pairs of peaks, which correspond to the current peaks of the cyclic voltammogram.This work was supported by KOSEF through the Research Center for Energy Conversion and Storage (RCECS), Korea Science and Engineering Foundation (no. 2000-2-30100-012-3) and by the Ministry of Information and Communication of Korea (Support Project of University Information Technology Research Center supervised by KIPA). The authors thank Cheil Industries, Inc., for the supporting electrolytes

Plastome phylogenomics and morphological traits analyses provide new insights into the phylogenetic position, species delimitation and speciation of Triplostegia (Caprifoliaceae)

Background The genus Triplostegia contains two recognized species, T. glandulifera and T. grandifora, but its phylogenetic position and species delimitation remain controversial. In this study, we assembled plastid genomes and nuclear ribosomal DNA (nrDNA) cistrons sampled from 22 wild Triplostegia individuals, each from a separate population, and examined these with 11 recently published Triplostegia plastomes. Morphological traits were measured from herbarium specimens and wild material, and ecological niche models were constructed. Results Triplostegia is a monophyletic genus within the subfamily Dipsacoideae comprising three monophyletic species, T. glandulifera, T. grandifora, and an unrecognized species Triplostegia sp. A, which occupies much higher altitude than the other two. The new species had previously been misidentifed as T. glandulifera, but difers in taproot, leaf, and other characters. Triplotegia is an old genus, with stem age 39.96Ma, and within it T. glandulifera diverged 7.94Ma. Triplostegia grandifora and sp. A diverged 1.05Ma, perhaps in response to Quaternary climate fuctuations. Niche overlap between Triplostegia species was positively correlated with their phylogenetic relatedness. Conclusions Our results provide new insights into the species delimitation of Triplostegia, and indicate that a taxonomic revision of Triplostegia is needed. We also identifed that either rpoB-trnC or ycf1 could serve as a DNA barcode for Triplostegi