The bipolar and unipolar resistive switching (BRS and URS) modes are first observed to coexist in the Au/SrTiO3/Pt cell fabricated by pulsed laser deposition. These two switching modes can be activated separately depending on the different current compliance (CC) during the electroforming process: with a lower CC (1 mA) the asymmetric BRS behaviour is measured in the voltage range −1.2 to +1 V, while the URS behaviour is observed with a higher CC (10 mA). On the basis of current–voltage characteristics, the switching mechanisms for the BRS and URS modes are considered as a change in Schottky-like barrier height and/or width at the Au/SrTiO3 interface and the formation and disruption of conduction filaments, respectively. The conversion between BRS and URS is reversible. Because each switching mode has a specific advantage, selecting the desired switching mode can broaden the application scope of the cell and enable large flexibility in terms of memory architecture.

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Composite fibrous electrospun membranes based on poly(DL-lactide) (PLA) and poly(ε-caprolactone) (PCL) were engineered to include borate bioactive glass (BBG) for the potential purposes of guided bone regeneration (GBR). The fibers were characterized using scanning and transmission electron microscopies, which respectively confirmed the submicron fibrous arrangement of the membranes and the successful incorporation of BBG particles. Selected mechanical properties of the membranes were evaluated using the suture pullout test. The addition of BBG at 10 wt.% led to similar stiffness, but more importantly, it led to a significantly stronger (2.37±0.51 N*mm) membrane when compared to the commercially available Epiguide® (1.06±0.24 N*mm) under hydrated conditions. Stability (shrinkage) was determined after incubation in a phosphate buffer solution from 24 h up to 9 days. The dimensional stability of the PLA:PCL-based membranes with or without BBG incorporation (10.07-16.08%) was similar to that of Epiguide® (14.28%). Cell proliferation assays demonstrated a higher rate of pre-osteoblasts proliferation on BBG-containing membranes (6.4-fold) over BBG-free membranes (4-5.8-fold) and EpiGuide® (4.5-fold), following 7 days of in vitro culture. Collectively, our results demonstrated the ability to synthesize, via electrospinning, stable, polymer-based submicron fibrous BBG-containing membranes capable of sustaining osteoblastic attachment and proliferation—a promising attribute in guided bone regeneration.

Gold nanoparticle-coated Pluronic-b-poly(L-lysine) nanoparticles (Pluronic-PLL@Au NPs) were synthesized via an easy one-step method and employed as carriers for the delivery of paclitaxel (PTX) in chemo-photothermal therapy, in which Pluronic-PLL acts as the reductant for the formation of AuNPs without the need for an additional reducing agent. Methods: The deposition of AuNPs on the surface of Pluronic-PLL micelles and the thermal response of the system were followed via ultraviolet-visible spectroscopy and dynamic light scattering. Calcein-AM and MTT assays were used to study the cell viability of MDA-MB-231 cells treated with PTX-loaded Pluronic-PLL@Au NPs, and we then irradiated the cells with NIR light. Results: An obvious temperature response was observed for the Pluronic-PLL@Au NPs. Blood compatibility and in vitro cytotoxicity assays confirmed that the Pluronic-PLL@Au NPs have excellent biocompatibility. Compared to Taxol, the PTX-loaded Pluronic-PLL@Au NPs exhibited higher cytotoxicity in MDA-MB-231 cells. All of these results and confocal laser scanning microscopy analysis results suggest that Pluronic-PLL@Au NPs greatly enhance the cellular uptake efficiency of the drug. Conclusion: As confirmed by in vitro and in vivo studies, the combination of chemotherapy and photothermal therapy can cause more damage than chemo- or photothermal therapy did alone, demonstrating the synergistic effect of chemo-photothermal treatment. Thus, the as-prepared Pluronic-PLL@Au NPs are promising for chemo-photothermal therapy.

Phonon spectra of CdS, ZnS, PbS, CuS, Ag2S, and ZnO quantum dots formed by using the Langmuir–Blodgett technology are investigated by Raman and infrared spectroscopies. The Raman spectra of structures show peaks corresponding to the scattering by longitudinal and transverse optical (LO and TO) phonons localized in quantum dots that confirm the formation of nanocrystals. In addition to TO and LO phonon modes, the modes observed in the IR spectra between the frequency positions of LO and TO phonons are attributed to the surface optical phonons in quantum dots.

The Na0.5Bi0.5TiO3(NBT) thin films sandwiched between Au electrodes and fluorine-doped tin oxide (FTO) conducting glass were deposited using a sol–gel method. Based on electrochemical workstation measurements, reproducible resistance switching characteristics and negative differential resistances were obtained at room temperature. A local impedance spectroscopy measurement of Au/NBT was performed to reveal the interface-related electrical characteristics. The DC-bias-dependent impedance spectra suggested the occurrence of charge and mass transfer at the interface of the Au/NBT/FTO device. It was proposed that the first and the second ionization of oxygen vacancies are responsible for the conduction in the low- and high-resistance states, respectively. The experimental results showed high potential for nonvolatile memory applications in NBT thin films.

The mobilities of NO ϩ ͑CH 3 CN͒ n cluster ions ͑nϭ0-3͒ drifting in helium and in mixtures of helium and acetonitrile ͑CH 3 CN͒ are measured in a flow-drift tube. The mobilities in helium decrease with cluster size ͓the mobility at zero field, K 0 ͑0͒ , is 22.4Ϯ0.5 cm 2 V Ϫ1 s Ϫ1 for NO ϩ , 12.3Ϯ0.3 cm 2 V Ϫ1 s Ϫ1 for NO ϩ ͑CH 3 CN͒, 8.2Ϯ0.2 cm 2 V Ϫ1 s Ϫ1 for NO ϩ ͑CH 3 CN͒ 2 and 7.5Ϯ0.5 cm 2 V Ϫ1 s Ϫ1 for NO ϩ ͑CH 3 CN͒ 3 ͔ and depend only weakly on the characteristic parameter E/N ͑electric field strength divided by the number density of the buffer gas͒. The size dependence is explained in terms of the geometric cross sections of the different cluster ions. The rate constants for the various cluster formation and dissociation reactions have also been determined in order to rule out the possibility that reactions occurring in the drift region influence the measurements in the mixtures. Since high pressures of acetonitrile are required to form NO ϩ ͑CH 3 CN͒ 2 and NO ϩ ͑CH 3 CN͒ 3 , the mobilities of these ions are found to be dependent on the acetonitrile concentration, as a result of anomalously small mobilities of these ions in acetonitrile ͓K 0 ͑0͒ ϭ0.041Ϯ0.004 cm 2 V Ϫ1 s Ϫ1 for NO ϩ ͑CH 3 CN͒ 2 and 0.044Ϯ0.004 cm 2 V Ϫ1 s Ϫ1 for NO ϩ ͑CH 3 CN͒ 3 ͔. These values are at least an order of magnitude smaller than any previously reported ion mobility, which can be partly explained by the large ion-permanent dipole interaction between the cluster ions and acetonitrile. The remaining discrepancies may be the result of momentum transfer outside the capture cross section, dipoledipole interactions, ligand exchange, the formation of long-lived collision complexes or the transfer of kinetic energy into internal energy of the cluster ion and the acetonitrile molecule.

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