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Based on green chemistry, 3D hierarchical ZnO microflowers (MFs) constructed from layered 2D nanosheets have been designed as carriers to uniformly load PdO/Pd nanoparticles by the calcination of the precursor (ZnO/Pd(II) microflowers) in air. The ZnO/Pd(II) microflowers are prepared by dipping the 3D ZnO MFs in an ethanolic solution of PdCl2 without involving additional agents. The as-prepared 3D hierarchical ZnO microflowers are a stable support to enhance the dispersibility of PdO/Pd nanoparticles to achieve better catalytic performance for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). In addition, the synergistic effect between the PdO and Pd nanoparticles is another major driver that promotes the catalytic process. Over 98% of 4-NP is reduced within 7 min. Furthermore, structural analysis of the ZnO/PdO/Pd microflowers can provide useful information for understanding structure-performance relationships.

We designed a facile and green self-assembly route for the large-scale production of bimetallic coordination polymer–Zn(MAA)2/Pd(II) nanoribbons by employing two terminal units with distinct hard–soft properties of the smallest semi-rigid methacrylate anion (MAA−) to combine with two different metal ions. The COO− (chemically hard base) served as the initial unit, which was applied to coordinate with the Zn2+ ions for constructing the host network of this Janus CPs by facilely adjusting the proportion of ethanol/water to control the degree of solvation. After soaking in an ethanol solution of PdCl2, the alkene units (chemically soft base) act as secondary donors to load the soft noble metal Pd2+ ions and form Zn(MAA)2/Pd(II) nanoribbons, which are ideal precursors of ZnO/PdO nanoribbons. By pyrolyzing the dual metal ion equipped Zn(MAA)2/Pd(II) precursors, ZnO nanoribbon supported PdO nanoparticles (NPs) with a well-defined structure were facilely fabricated on a large scale. Furthermore, the as-obtained ZnO/PdO nanoribbons exhibit efficient catalytic performance for the reduction of 4-NP, which can convert 99.3% of the substrates within 6 min. This superior catalytic performance may be attributed to the well-dispersed PdO nanoparticles as well as the absence of additional agents introduced a green synthetic method.

Large-scale Ni-based nano-sized coordination polymers (Ni-nCPs) are facilely constructed by a self-assembled approach at room temperature and atmosphere pressure. In this strategy, we use only the environmentally friendly solvents of water and ethanol, and the synthesis of 2D Ni-nCPs via a self-assembly route appears close to the “green chemistry” concept. In addition, the morphologies of the Ni-nCPs can be easily adjusted by the water/ethanol ratio. Owing to its unique 2D ultrathin nature and large specific surface area, Ni-nCPs-1 achieves a great number of channels for the transport of electrons and ions and electrochemically redox active sites for a faradaic reaction. Therefore, battery-type Ni-nCPs-1 electrodes have a bright prospect in energy storage, and can reach an outstanding specific capacitance value as high as 1066.9 F g−1 at 1 A g−1. Additionally, the asymmetric supercapacitor (Ni-nCPs-1//active carbon) displays a high energy density of 47.9 W h kg−1 at a power density of 440 W kg−1 and an excellent long-term cycle stability. This work may open up a new path in advanced electrode materials for efficient and real-time energy storge applications.

3D hierarchical CuS architectures consisting of 1D nanotubes have been synthesized by the combination of the self-assembly method and a simple solvothermal process. The hierarchical structures not only provide a large number of active sites on the surfaces, but also integrate the advantages of 1D nanotubes for molecular or ionic transport and 3D for mechanical stability. The hierarchical CuS architectures can be a Fenton-like catalyst with excellent catalytic performance. The degradation rate constant k of 3D hierarchical CuS is 8.37 × 10−2 min−1 at the concentration of rhodamine B (RhB) of 50 mg/mL under visible light irradiation.

CoO-C nanowires can be large-scale synthesized with the Co(MAA)2 nanowires as precursors, which are fabricated by a simple self-assembled process at room temperature. Since the Co2+ ions are uniformly distributed in the precursor at molecular level, the generated CoO nanoparticles are well dispersed in the whole carbon nanowires. Such “brick and cement” hybrid structures of CoO and carbon are regarded as reasonable structures to achieve supercapacitor with high specific capacitance and outstanding cycle performance. To investigate the effect of heating rates on the electrochemistry performance, CoO-C nanowires with different heating rates are prepared in the atmosphere of nitrogen. The as-prepared CoO-C electrode shows the highest specific capacity of 187 F/g at the current density of 1 A/g. More importantly, the cyclic stability of the CoO-C hybrid electrode is extraordinary. Over 90% of the capacitance is retained after a long cycle exceeding 12,000 cycles.

Epithelial-mesenchymal interactions are required for tissue growth and gene expression patterns during odontogenesis. We showed previously that Sonic hedgehog (SHH) is detectable in both dental epithelium and mesenchyme, while Shh transcripts are present in dental epithelium only, suggesting that SHH functions as an autocrine signal in epithelium and a paracrine signal in mesenchyme. This hypothesis was tested here. We found by in situ hybridization that the SHH autocrine receptor Ptch-2 is indeed expressed in dental epithelium whereas the paracrine receptor Ptc is expressed in mesenchyme. Bovine bell stage tooth germs were microsurgically separated into epithelial and mesenchymal portions and the resulting tissue fragments were organ-cultured. In epithelium fragments cultured by themselves, gene expression of Shh and Gli-1 (a putative transcriptional mediator of hedgehog signaling) was significantly decreased in both inner dental epithelium and stratum intermedium layers; this was accompanied by a sharp drop in epithelial cell proliferation. However, in companion control tissue fragments containing both epithelium and mesenchyme, Shh and Gli-1 expression as well as cell proliferation were maintained. Treatment of dental epithelial or mesenchymal cell populations in monolayer cultures with exogenous recombinant SHH stimulated cell proliferation. Together, the data provide clear evidence that Shh is synthesized by dental epithelium, reaches the underlying mesenchyme, and appears to act as an autocrine mitogen for epithelial cells and a paracrine mitogen for mesenchymal cells, thus exerting crucial functions in tooth germ growth, morphogenesis, and tissue-tissue interactions of bell stage of odontogenesis.

Joint formation is a complex and multistep process during skeletogenesis. It involves joint site determination, local chondrocyte de-differentiation, formation of a mesenchymal interzone separating contiguous cartilaginous elements, production of a fluid-rich synovial cavity, and emergence of articu

Chondrocyte proliferation is important for skeletal development and growth, but the mechanisms regulating it are not completely clear. Previously, we showed that syndecan-3, a cell surface heparan sulfate proteoglycan, is expressed by proliferating chondrocytes in vivo and that proliferation of cultured chondrocytes in vitro is sensitive to heparitinase treatment. To further establish the link between syndecan-3 and chondrocyte proliferation, additional studies were carried out in vivo and in vitro. We found that the topographical location of proliferating chondrocytes in developing chick long bones changes with increasing embryonic age and that syndecan-3 gene expression changes in a comparable manner. For in vitro analysis, mitotically quiescent chondrocytes were exposed to increasing amounts of fibroblast growth factor-2 (FGF-2). Proliferation was stimulated by as much as 8-10-fold within 24 h; strikingly, this stimulation was significantly prevented when the cells were treated with both fibroblast growth factor-2 (FGF-2) and antibodies against syndecan-3 core protein. This neutralizing effect was dose-dependent and elicited a maximum of 50-60% inhibition. To establish specificity of neutralizing effect, cultured chondrocytes were exposed to FGF-2, insulin-like growth factor-1, or parathyroid hormone, all known mitogens for chondrocytes. The syndecan-3 antibodies interfered only with FGF-2 mitogenic action, but not that of insulin-like growth factor-1 or parathyroid hormone. Protein cross-linking experiments indicated that syndecan-3 is present in monomeric, dimeric, and oligomeric forms on the chondrocyte surface. In addition, molecular modeling indicated that contiguous syndecan-3 molecules might form stable complexes by parallel pairing of beta-sheet segments within the ectodomain of the core protein. In conclusion, the results suggest that syndecan-3 is a direct and selective regulator of the mitotic behavior of chondrocytes and its role may involve formation of dimeric/oligomeric structures on their cell surface.