Fabrication and characterization of novel hydroxyapatite/porous carbon composite scaffolds

Novel hydroxyapatite (HA)/porous carbon composite scaffolds were prepared by applying sonoelectrodeposition and a subsequent hydrothermal treatment to previous carbonized phenolic resin coated polyurethane sponges. The interconnected pore network and morphology of HA/porous carbon composite scaffolds were determined by scanning electron microscope (SEM), and the whole surface of porous carbons were evenly coated with the deposited HA layer which was confirmed by EDS and XRD. The porosity (83.5 ± 0.3%) and the bulk density (0.297 ± 0.009 g·cm⁻³) of HA/porous carbon scaffolds were detected by the Archimedes method. The compressive and flexural strength of the scaffolds is 1.187 ± 0.064 MPa and 0.607 ± 0.268 MPa, respectively. Compared with the polymeric surface of 24-well cell culture plates, these novel scaffolds significantly promote the proliferation of human osteoblast-like MG-63 cells, indicating that this novel HA/porous carbon composite scaffold could be used for in vitro 3D culture of osteoblasts.     

Tuning Conversion Efficiency in Metallo Endohedral Fullerene‐Based Organic Photovoltaic Devices

Here the influence that 1‐(3‐hexoxycarbonyl)propyl‐1‐phenyl‐[6,6]‐Lu₃N@C₈₁, Lu₃N@C₈₀–PCBH, a novel acceptor material, has on active layer morphology and the performance of organic photovoltaic (OPV) devices using this material is reported. Polymer/fullerene blend films with poly(3‐hexylthiophene), P3HT, donor material and Lu₃N@C₈₀–PCBH acceptor material are studied using absorption spectroscopy, grazing incident X‐ray diffraction and photocurrent spectra of photovoltaic devices. Due to a smaller molecular orbital offset the OPV devices built with Lu₃N@C₈₀–PCBH display increased open circuit voltage over empty cage fullerene acceptors. The photovoltaic performance of these metallo endohedral fullerene blend films is found to be highly impacted by the fullerene loading. The results indicate that the optimized blend ratio in a P3HT matrix differs from a molecular equivalent of an optimized P3HT/[6,6]‐phenyl‐C₆₁‐butyric methyl ester, C₆₀–PCBM, active layer, and this is related to the physical differences of the C₈₀ fullerene. The influence that active layer annealing has on the OPV performance is further evaluated. Through properly matching the film processing and the donor/acceptor ratio, devices with power conversion efficiency greater than 4% are demonstrated.     

Subcellular Localization of Thiol-Capped CdTe Quantum Dots in Living Cells

Internalization and dynamic subcellular distribution of thiol-capped CdTe quantum dots (QDs) in living cells were studied by means of laser scanning confocal microscopy. These unfunctionalized QDs were well internalized into human hepatocellular carcinoma and rat basophilic leukemia cells in vitro. Co-localizations of QDs with lysosomes and Golgi complexes were observed, indicating that in addition to the well-known endosome-lysosome endocytosis pathway, the Golgi complex is also a main destination of the endocytosed QDs. The movement of the endocytosed QDs toward the Golgi complex in the perinuclear region of the cell was demonstrated. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Enhanced Performance of Osteoblasts by Silicon Incorporated Porous TiO2 Coating

Silicon (Si) incorporated porous TiO 2 coating (Si-TiO 2) prepared on titanium (Ti) by micro-arc oxidation (MAO) technique was demonstrated to be cytocompatible in previous studies.In view of the potential clinical applications,a detailed in vitro study of the biological activity of Si-TiO 2 coating,in terms of osteoblast (MC3T3-E1 cells) morphology,proliferation,differentiation and mineralization was performed.Immunofluorescent staining indicated that cells seeded on the Si-TiO 2 coating showed improved adhesion with developing mature cytoskeletons,which contained numerous distinct and well-defined actin stress fibers in the cell membranes compared with those on the TiO 2 coating and Ti plate.Results from proliferation assay showed that the proliferation rate of cells seeded on the Si-TiO 2 coating was significantly faster than that on the TiO 2 coating and Ti plate.Furthermore,the analysis of osteogenic gene expression demonstrated that the Si-TiO 2 coating stimulated the expression of osteoblast-related genes and promoted differentiation and mineralization of MC3T3-E1 cells.In addition,the Si-TiO 2 coating differentially regulated Wnt signaling pathway by up-regulating the expression of low-density lipoprotein (LDL) receptor-related protein 5 (Lrp5),and downregulating the expression of Dickkopf-1 (Dkk1).All together,these results indicate that the investigated titanium with Si-TiO 2 coating is biocompatible and a good candidate material used as implants.     

Preparation of TiO2 paste starting from organic colloidal suspension for semi-transparent DSSC photo-anode application

We investigated the effect of different formulation strategies on the preparation of TiO2 screen printable pastes starting from the same organic colloidal suspension for dye-sensitized solar cells (DSSCs) application. As first strategy, we developed TiO2 pastes starting from nano-crystalline powder dried from the synthetized suspension, with and without an additional acid treatment, obtaining non-transparent scattering sintered layers. Instead, we demonstrate that starting from the sol solution is a key factor to obtain a well nano-dispersed TiO2 paste. The novel paste process resulted in a final homogeneous and semitransparent porous layer (T>80% @450–550 nm). In order to evaluate the properties of TiO2 powders and inks we performed thermal analysis, BET and FTIR measurements. The films were screen printed on FTO (fluorinedoped tin oxide) glass and characterized after sintering via profilometry, FE-SEM analysis and UVVis spectra measurements. The photo-anode was further validated in small (2 cm2) and large (90 cm2) active area DSSCs, giving an average photovoltaic efficiency respectively of 5,22% and 2,39%, comparable with commercially available TiO2 paste with similar composition.     

商陆色素敏化TiO_2薄膜太阳能电池的初步研究

本文从商陆科植物商陆（Phytolacca acinosa Roxb）浆果中提取一种紫红水溶性色素,进行了敏化TiO2电极制备太阳能电池实验。结果表明：在紫外线强度134×100uw/cm2的模拟太阳光照射下,所制成的染料敏化电池可以产生0.13V的开路电压和0.007mA的短路电流;在紫外线强度90×100uw/cm...     

An original observer design for reduced sensor control of Packed U Cells based renewable energy system

This paper presents an original Switched Observer (SO) for reduced-sensor control of a grid-connected Packed U Cells (PUC) multilevel inverter. The proposed SO performance is evaluated using a single-phase 7-level PUC inverter connected to the grid through filtering inductor. Based on the actual grid current, the proposed SO estimates accurately the PUC capacitor voltage, which is fed to the Model Predictive Control (MPC) algorithm while making use of a hybrid model considering both discrete and continuous variables. For real-time application, necessary conditions are given to guarantee the practical stability of the proposed SO under system parameters and input voltage variations according to the selected switching pattern. Theoretical analysis and simulation investigations are conducted to prove that the proposed SO-MPC scheme is stable in closed-loop for all system configurations and has good performances even during various disturbances (load change, parameters mismatch, and input voltage variation).     

A multiobjective study of the Gaussian cluster paging in the Reporting Cells strategy

Mobile location management is an important task in mobile networks. This paper presents an analysis of the Gaussian cluster paging in the Reporting Cells strategy. Reporting Cells define a location update strategy in which some network cells are configured as Reporting Cells with the aim of tracking the subscribers’ movement. On the other hand, the Gaussian cluster paging is a paging scheme where we assume that the probability of finding a callee's terminal decreases as we move away from the last updated location. This paging scheme is studied in a multiobjective way for different probability thresholds, and considering time-delay constraints. With the goal of finding the best possible sets of non-dominated solutions, we propose our implementation of a well-known multiobjective evolutionary algorithm: the Non-dominated Sorting Genetic Algorithm II. By means of an experimental study, we show that each probability threshold has its own non-dominated region in the objective space.     

Cell behaviour on a polyaniline nanoprotrusion structure surface

The extracellular matrix provides mechanical support and affects cell behaviour. Nanoscale structures have been shown to have functions similar to the extracellular matrix. In this study, we fabricated nanoprotrusion structures with polyaniline as cell culture plates using a simple method and determined the effects of these nanoprotrusion structures on cells.