Granular materials, composed of densely packed particles, are known to possess unique mechanical properties that are highly dependent on the surface structure of the particles. A microscopic ...understanding of the structure‐property relationship in these systems remains unclear. Here, supra‐nanoparticle clusters (SNPCs) with precise structures are developed as model systems to elucidate the unexpected elastic behaviors. SNPCs are prepared by coordination‐driven assembly of polyhedral oligomeric silsesquioxane (POSS) with metal‐organic polyhedron (MOP). Due to the disparity in sizes, the POSS‐MOP assemblies, like their classic nanoparticles counterparts, ordering is suppressed, and the POSS‐MOP mixtures will vitrify or jam as a function of decreasing temperature. An unexpected elasticity is observed for the SNPC assemblies with a high modulus that is maintained at temperatures far beyond the glass transition temperature. From studies on the dynamics of the hierarchical structures of SNPCs and molecular dynamic simulation, the elasticity has its origins in the interpenetration of POSS‐ended arms. The physical molecular interpenetration and inter‐locking phenomenon favors the convenient solution or pressing processing of the novel cluster‐based elastomers.
Supra‐nanoparticle clusters (SNPCs) were synthesized by convergence of metal–organic polyhedron scaffolds with precise giant building blocks. The mechanical properties and structural dynamics can be regulated by fine‐tuning the surface functionalization of the terminal POSS moieties. Unexpected elasticity with high Young's modulus of the OPOSS‐ended SNPCs was found to be highly correlated with the interpenetration of the neighboring GLs.
The purpose of this study was to investigate the effects of secreted protein acidic and rich in cysteine (SPARC) on the maintenance of limbal epithelial stem cell (LESC) stemness and restoration of ...ocular surface. To determine the suitable concentration of SPARC for LESC culture, the marker expression, mitogenic effect, and holoclone‐forming capacity of LESCs treated with different concentrations of SPARC were analyzed. To investigate the mechanism of SPARC's action on the preservation of LESCs stemness, the phosphorylation of related signaling pathways was evaluated by Western blotting. A corneal wound model was established to verify the function of SPARC in ocular surface repair. Consecutive subculturing, colony‐forming efficiency, immunofluorescence, and 5‐ethynyl‐2‐deoxyuridine incorporation assays indicated that 1 μg/mL SPARC was a suitable concentration to stimulate LESC proliferation and preserve their proliferative potential. Compared with a control group, 1 μg/mL SPARC effectively increased the expression of ABCG‐2, Bmi‐1, and Ki67, while decreasing that of CK3/12. The mitogenic effect of SPARC on LESCs was found to be mediated by the phosphorylation of c‐Jun N‐terminal kinase (JNK) and p38‐MAPK signaling pathways, whereas the inhibitors of JNK and p38 MAPK reduced the marker expression and mitogenic capacity of LESCs. In a corneal injury model, SPARC facilitated corneal epithelial wound healing and promoted the proliferation of p63α‐positive cells both in the limbus and in the epithelial healing front. SPARC promotes proliferation while suppressing spontaneous differentiation of LESCs through JNK and p38‐MAPK signaling pathways, suggesting that SPARC is a promising factor for the improvement of LESCs culture in vitro and in vivo.
When cultured in medium containing1μg/mL secreted protein acidic and rich in cysteine (SPARC) in vitro, limbal epithelial stem cells (LESCs) showed a greater proliferative and clonogenic capacity and a higher expression of LESCs marker through c‐Jun N‐terminal kinase/p38 MAPK signal pathway. In corneal wounding model, exogenous SPARC accelerated corneal epithelial wound healing and promoted the proliferation of p63α‐positive cells both in limbus and in epithelial healing front.
•Different BODPY-based supramolecules are categorized.•The structure-properties effet of BODIPY-based supramolecules are summarized.•Diverse BODIPY-based supramolecules photophysical properties and ...applications are highlighted.
In the last decades, BODIPY-based supramolecules have gained considerable research interest due to their excellent photophysical properties, good photostability and widespread applications in responsive materials, gel, liquid crystal, white light emission materials and phototherapy, etc. These supramolecules provide versatile platforms for functionalization due to different reactive sites in BODIPY core. In this review, we summarize the latest progresses on BODIPY-based supramolecules, including the empirical design strategies, photophysical manipulation and various applications.
Amorphous molybdenum sulfide (MoS x ) is currently being developed as an economically viable and efficient catalyst for the electrochemical hydrogen evolution reaction (HER). An important yet ...unsolved problem in this ongoing effort is the identification of its catalytically active sites for proton reduction. In this work, cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy were used to investigate the catalytically active sites and structural evolution of MoS x films during HER in 1 M HClO4 electrolyte. Transformation of anodically deposited MoS x (x ≈ 3) to a structure with MoS2 composition during the cathodic sweep of a CV was demonstrated using XPS and operando Raman spectroscopy. Interestingly, a Raman peak at 2530 cm–1 was recorded at potentials relevant to H2 evolution, which we ascribed to the S–H stretching vibration of MoS x –H moieties. This assignment was corroborated by H/D isotope exchange experiments. Mo–H (or Mo–D) stretching vibrations were not observed, which thus allowed us to rule out Mo centers as catalytic sites for proton reduction to H2. Density functional theory (DFT) calculations were performed on a variety of MoS x structures to capture the heterogeneous nature of amorphous materials and corroborated the assignments of the observed vibrational frequencies. On the basis of these experimental measurements and quantum chemical simulations, we have for the first time directly pinpointed the sulfur atoms in amorphous MoS x to be the catalytically active sites for evolving H2.
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•The solubilities of NH3 in ethylamine hydrochloride plus acetamide DESs were determined.•The solubility data were fitted to Krichevesky-Kasarnovsky equation to calculate Henry’s ...constants.•The thermodynamic functions such as enthalpy, Gibbs free energy and entropy changes for NH3 absorption were estimated.•The densities and viscosities of ethylamine hydrochloride plus acetamide DESs were also determined.•The density and viscosity data were fitted to linear equation and Vogel-Fulcher-Tammann equation respectively.
Deep eutectic solvents (DESs) are a novel class of green solvents with promising application in gas separation. The physical properties of, and gas solubilities in DESs are fundamental data for industrial process design. In this work, the densities and viscosities of ethylamine hydrochloride (EaCl) plus acetamide (AA) mixtures were determined in the temperature range of (313.2–353.2) K. The density data and viscosity data were fitted to a linear equation and the Vogel-Fulcher-Tammann equation respectively. Furthermore, the solubilities of NH3 in EaCl + AA mixtures were determined in the temperature range of (313.2–353.2) K and pressure range of (0–300.0) kPa. It is found that the isothermal profiles for NH3 absorption slightly deviate from ideal type, probably due to the strong hydrogen-bond interaction between NH3 and EaCl. The solubilities of NH3 in EaCl + AA mixtures are fairly good, with the value of 3.84 mol·kg−1 at 313.2 K and 96.4 kPa for EaCl + AA (1:1). The solubility data were fitted to the Krichevsky-Kasarnovsky equation to calculate the Henry’s constants of NH3 in EaCl + AA mixtures. With the Henry’s constants at different temperatures, the thermodynamic functions such as enthalpy changes, Gibbs free energy changes and entropy changes for NH3 absorption in EaCl + AA mixtures were also estimated.
Developing highly luminescent and extensively stable silver cluster‐assembled materials (SCAMs) from the inferior luminogens and unstable silver cluster is an important and challenging issue. Herein, ...a new luminescent three‐dimensional SCAM (Ag12CPPP, Ag12(StBu)6(CF3COO)6(CPPP)2(DMAc)12n; CPPP=2,5‐bis(4‐cyanophenyl)‐1,4‐bis(4‐(pyridine‐4‐yl)‐phenyl)‐1,4‐dihydropyrrolo3,2‐bpyrrole, DMAc=dimethylacetamide) was designed and synthesized with a quadridentate rigid emission ligand (CPPP) and a silver–chalcogenolate cluster (SCC) containing 12 AgI atoms. The luminescence study indicates that CPPP is an aggregation‐caused quenching (ACQ) molecule with twisted intramolecular charge transfer (TICT) character. Benefiting from the strong immobilization effect in the robust framework, the quantum yield of CPPP is greatly enhanced in Ag12CPPP compared with that of CPPP in solution or in the solid state. As a result, Ag12CPPP exhibits typical matrix coordination induced emission (MCIE) effect. Such efficient rigidifying methodology provides a promising approach for enhancing luminescence of ACQ molecules in an aggregated state and strengthening the silver cluster in an unstable state.
Cluster lighting: Matrix coordination induced emission (MCIE) effect was observed in a new three‐dimensional silver cluster‐assembled material (SCAM). The quantum yield (QY) of the SCAM is much higher than that of the quadridentate ligand (see figure).
A substrate integrated waveguide (SIW) H-plane horn antenna with miniaturized longitudinal dimension and increased gain is proposed by loading slow-wave (SW) structures in the form of metallized ...blind via-holes inside the flare region of the horn for vehicular millimeter wave communications. The slow-wave structure can reduce the phase velocity around the center line of the broad wall and compensate the large phase difference between the center and edge of the aperture caused by reduction of longitudinal length of the horn. Compared with optimum horn with the same aperture width, the gain of miniaturized SIW horn is successfully increased, while the longitudinal dimension is decreased. A SW-SIW horn antenna which covers the 28 GHz band (27.5-28.35 GHz) allocated by Federal Communications Commission for the 5G millimeter wave communications is designed to verify the feasibility of the miniaturized SIW horn antenna facilitated by the proposed slow-wave structure. The SW-SIW horn realizes 53.83% reduction of longitudinal length compared with the optimum horn. The gain of the SW-SIW horn is improved by 1.1 dB on average over 27.5-28.5 GHz compared with optimum horn. A prototype of the proposed SW-SIW H-plane horn antenna is manufactured and measured. The measured results agree well with the simulations.
To integrate treatments of photothermal therapy, photodynamic therapy (PDT), and chemotherapy, this study reports on a multifunctional nanocomposite based on mesoporous silica‐coated gold nanorod for ...high‐performance oncotherapy. Gold nanorod core is used as the hyperthermal agent and mesoporous silica shell is used as the reservoir of photosensitizer (Al(III) phthalocyanine chloride tetrasulfonic acid, AlPcS4). The mesoporous silica shell is modified with β‐cyclodextrin (β‐CD) gatekeeper via redox‐cleavable Pt(IV) complex for controlled drug release. Furthermore, tumor targeting ligand (lactobionic acid, LA) and long‐circulating poly(ethylene glycol) chain are introduced via host–guest interaction. It is found that the nanocomposite can specifically target to hepatoma cells by virtue of the LA targeting moiety. Due to the abundant existence of reducing agents within tumor cells, β‐CD can be removed by reducing the Pt(IV) complex to active cisplatin drug for chemotherapy, along with the releasing of entrapped AlPcS4 for effective PDT. As confirmed by in vitro and in vivo studies, the nanocomposite exhibits an obvious near‐infrared induced thermal effect, which significantly improves the PDT and chemotherapy efficiency, resulting in a superadditive therapeutic effect. This collaborative strategy paves the way toward high‐performance nanotherapeutics with a superior antitumor efficacy and much reduced side effects.
Collaborative tumor‐targeted therapy: A highly integrated nanocomposite is constructed based on mesoporous silica‐coated gold nanorods for tumor‐targeted therapy by virtue of the GNR‐mediated PTT, PS‐mediated PDT, and platinum‐based chemotherapy. In vitro and in vivo results confirm that this multifunctional nanocomposite can serve as an ideal platform for tri‐model high‐performance tumor therapy.
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