Search

In this study, we develop the optimum composition of copper oxide/ruthenium oxide and multi-walled carbon nanotubes (CuO/RuO2/MWCNTs) ternary nanocomposite via a hydrothermal method as an efficient electrode material for supercapacitor applications. The ratio between CuO and RuO2 varied to improve the electrochemical performance of the electrode. The synthesized nanocomposites are analyzed by high-resolution scanning electron microscopy (HR-SEM), thermo gravimetric analyzer (TGA) and electrochemical impedance spectroscopy (EIS). Furthermore, the elemental composition is analyzed by energy dispersive X-ray (EDX) spectroscopy and the specific capacitance was analyzed by cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) methods. The electrochemical investigations is conducted in a three-electrode system and the sample is attached on a stainless steel plate as the working electrode; platinum wire works as the counter electrode and Ag/AgCl electrode as the reference electrode, adopting 3 M (NH4)2SO4 as the electrolyte. The resultant of CuO/RuO2/MWCNT nanocomposite with 7 wt% Cu and 20 wt% Ru was found to perform the highest specific capacitance of 461.59 F/g in a current density of 1 A/g.

Industrial wastewater often contains heavy metals, like lead, copper, nickel, cadmium, zinc, mercury, arsenic, and chromium. Overdoses of heavy metals will impose a severe threat to human health. Adsorption is the most efficient way of wastewater treatment for eliminating heavy metals. A novel material-reusable hydrogel-based adsorbent was developed in overcoming the regeneration issue. The polyethylene glycol diacrylate-3-sulfopropyl methacrylate potassium salt (PEGDA-SMP) hydrogel performed an ion-exchange rate to remove heavy metals from wastewater in 30-120 min. The adsorption capacity of PEGDA-SMP increases the increasing pH of a solution, in which pH 5 reaches the maximum. Pseudo-second-order adsorption and the Langmuir adsorption model can fully describe the adsorption properties of PEGDA-SMP for heavy metals. PEGDA-SMP prefers to exchange Pb2+ through K+, and its adsorption capacity can achieve 263.158 mg/g. Ag+, Zn2+, Ni2+, and Cu2+ were 227.27, 117.647, 102.041, and 99.010 mg/g, respectively. The hydrated ionic radius of the heavy metal might play an essential role to affect the adsorption preference. The removal efficiency of heavy metals can approach over 95% for each heavy metal. PEGDA-SMP performs rapid desorption and reaches desorption equilibrium in 15 min. After 10 consecutive adsorption-desorption cycles, the adsorption capacity remained over 90%. The hydrogel developed in this study showed reversible heavy metal absorption. Therefore, excellent adsorption-desorption properties of PEGDA-SMP can be potentially extended to industrial wastewater for removing heavy metals.

In an attempt to improve the photocatalytic activity of anatase TiO2, we developed a composite photocatalyst composed of hollow TiO2 microspheres (hTS) and graphene. The hTS were prepared through a two-step hydrothermal process, where SiO2 microspheres with desirable diameters of 100–400 nm were used as sacrificial templates. Accordingly, the effect of the hTS cavity size on the activity of the catalyst in wet CO2 photoreduction (CO2PR) was studied. Furthermore, it was established that the hydrothermal pH value crucially influences the photocatalytic activity of the hTS photocatalyst, as well as its composition and microstructure. The hTS photocatalyst was also combined with graphene (0–90 wt%) to improve its photocatalytic activity. This study provides insight into the optimal microsphere diameter, hydrothermal pH value, and graphene/hTSx ratio required for designing hollow microsphere-based photocatalysts with enhanced CO2PR performances.

We report the synthesis of Pt-Sn binary and Pt-Ru-Sn ternary alloy nanoparticles (NPs) dispersed on mesoporous carbon CMK-3 for bioalcohol fuel cell applications where ethanol, ethylene glycol, and fermentative hydrogen production effluent were used as the fuels. The proposed alloy electrocatalysts, denoted as Pt 20 Ru x Sn y @C (where 20, x, and y represent the weight fractions of Pt, Ru, and Sn, respectively), were examined using scanning electron microscopy, energy-dispersive X-ray spectroscopy mapping, transmission electron microscopy, Brunauer-Emmett-Teller measurements, X-ray diffraction analysis, and electrochemical measurements, in order to determine their morphologies, microstructures, compositions, phase structures, and electrochemical characteristics. The effects of the Sn content on the following factors were examined: 1) average particle size of the alloy NPs, 2) mesoporosity, 3) electrochemically active surfaces of Pt 20 Ru x Sn y @C, and 4) ethanol oxidation reaction and ethylene glycol oxidation reaction activities. Higher Sn contents improved the catalytic efficiency of Pt 20 Ru x Sn y when x = 0 or x = 10, with the optimized compositions being Pt 20 Sn 30 and Pt 20 Ru 10 Sn 15 for the binary and ternary alloys, respectively. Based on the ethanol and ethylene glycol oxidation reactions, we explain the role of Sn in promoting C C bond cleavage and in improving catalyst tolerance against poisoning. Overall, for both the ethanol system and the ethylene glycol system, the catalytic activities could be arranged as follows: Pt 20 Ru 10 Sn 15 @C > Pt 20 Sn 30 @C > Pt 20 Ru 10 @C > Pt 20 @C. The chronoamperometric measurement shows that Pt 20 Ru 10 Sn 15 @C is more stable than commercial E-TEK Pt/C catalyst under ethanol environment. Finally, the catalyst Pt 20 Ru 10 Sn 15 was used successfully to demonstrate the feasibility of using the bioalcohol from a fermentation effluent as a fuel.

This article describes the application of an e-learning system on the trainings of new employees in a LCD(Light Emitting Diode) enterprise. An international LCD chips manufacturing company regularly recruit and train new employees. Among the training content, the manufacturing process of epitaxy wafers to chips is abstract and difficult to understand, particular for those without engineering backgrounds. To make the training activities effective, the authors designed e-learning courseware with simulations of manufacturing processes. These web-based learning materials can be accessed before or after the training session. An experiment was conducted to evaluate the effectiveness of this e-learning system. The results revealed that this e-learning system significantly improved the learners content comprehension.

Extensive atomistic simulations of the mechanical deformation of defective nanowires (NWs) were performed using the embedded-atom molecular dynamics modeling approach. The investigation focuses on the coupled effects of various vacancy cluster (VC) defects, operation temperature, and wire cross-sectional area on the mechanical properties and plastic deformations of defective NWs. The stress-strain behaviors show that the elastic modulus is independent of the vacancy cluster defects. Quasi-linear decreasing Young's moduli were observed with increasing operation temperature. For a given operation temperature, NW Young's modulus increased with increasing NW size.

In this study, low-energy microwave annealing(MWA) is used to activate the germanium material which is new promising and might replace silicon in the future. A novel MWA method with two steps applies to germanium for solid phase epitaxial recrystallization(SPER) and dopants activation. The purpose of the first step MWA at 2P(1.2kW) for 75 sec is to quickly repair the destroyed crystal lattices which are caused by ion implantation to achieve the SPER. The second step MWA at 1.5P(0.9kW) for 300 sec is used to activate the phosphorus dopants effectively without diffusion and de-activation. The target dopant activation level concentration will be more than 1020 cm−3, and sheet resistance decreases to 78 ohm/sq.

This paper investigates degradation behavior induced by the self-heating effect for InGaZnO (IGZO) thin-film transistors (TFTs). Both the surrounding oxide and other thermal insulating materials, as well as the low thermal conductivity of the InGaZnO layer itself, cause the self-heating effect in InGaZnO TFTs. The heated channel layer enhances the threshold voltage shift, and the evolution of threshold voltage shift is found to be dominated by charge-trapping effects. Moreover, a nonuniform distribution of channel carrier concentration leads to an uneven temperature distribution throughout the IGZO active layer, which results in the asymmetrical degradation behavior after the self-heating operation. Further verifications indicate that the degree of the threshold voltage shift is only dependent on stress power, regardless of stress Vg, Vd, and channel length. Further, two-stage dependence of the threshold voltage shift on dynamic stress frequency is found.

ThispaperinvestigatestheeffectofDCandACbias-stressinduceddegradationbehaviorinamorphousInGaZnOthin-filmtransistors (TFTs)underlightillumination.Draincurrent-gatevoltage(ID-VG)aswellascapacitance-voltage(C-V)measurementsareemployed to analyze the degradation mechanism. Illuminated DC stress leads to not only a negative parallel shift but also a C-V curve distortion at the off-state. This can be attributed to barrier-lowering near the drain side due to the asymmetrical hole-trapping effect. To further verify the origin of the degradation behavior, AC bias with identical stress voltage is imposed on either the gate terminal or the drain terminal. It is deduced that the hole-trapping phenomenon near the drain side is dominated by the voltage across the gate and drain, and is responsible for the degradation characteristic after stress carried out under light illumination.

We previously reported the preparation and characterization of ternary nanoparticles with the negative surface charge, which comprises histidine-conjugated polyallylamine (PAA-HIS)/DNA core complex and a single-stranded oligonucleotide outer layer, to transfect various cell lines. As a continued effort, here the investigations on the endocytotic mechanisms involved in the uptake of the oligonucleotide-coated PAA-HIS/DNA complexes are reported. Interestingly, these complexes showed enhanced transfection efficiency only when deoxyadenosine-containing oligonucleotides were deposited on the PAA-HIS/DNA complex surface. The addition of uncomplexed oligonucleotide, free adenosine and adenosine receptor antagonist significantly inhibited the transfection efficiency of oligonucleotide-coated PAA-HIS/DNA complexes. These results indicated that the oligonucleotide-coated PAA-HIS/DNA complexes could specifically recognize adenosine receptors on the cell surface and were taken up by adenosine receptor-mediated process. Uptake and transfection experiments with various endocytic inhibitors suggested that, after receptor/ligand binding, oligonucleotide-coated PAA-HIS/DNA/complexes were mainly internalized via caveolae-mediated pathway to result in effective intracellular processing for gene expression. In conclusion, both adenosine receptor and caveolae-mediated endocytosis play important roles in oligonucleotide-mediated gene transfer.

DNA vaccination is a novel immunization strategy that possesses many potential advantages over other vaccine strategies. One of the major difficulties hindering the clinical application of DNA vaccination is the relative poor immunogenicity of DNA vaccines. Poly(methyl methacrylate) (PMMA) is a synthetic polymer approved by the Food and Drug Administration for certain human clinical applications such as the bone cement. In vivo, PMMA particles are phagocytosable and have the potential to initiate strong immune responses by stimulating the production of inflammatory cytokines. In this study, we synthesized a series of PMMA particles (PMMA 1-5) with different particle sizes and surface charges to test the feasibility of implementing such polymer particles for DNA vaccination. To our knowledge, this is the first report to show that the gene gun can deliver DNA vaccine by propelling PMMA particles mixed with plasmid DNA for cervical cancer. It was found that PMMA 4 particles (particle size: 460 +/- 160 nm, surface charge: +11.5 +/- 1.8 mV) stimulated the highest level of TNF-alpha production by macrophages in vitro and yielded the best result of antitumor protection in vivo. Therefore, our results possess the potential for translation and implementation of polymer particles in gene gun delivering DNA vaccination.

Copolymers of 3-hydroxyvalerate (HV) and 3-hydroxyhexanoate (HHx) membranes are a new family of biomaterials for tissue engineering applications. The object of this study is to investigate the behavior of rat tooth germ cells on various 3-hydroxyl-butyrate-co-3-hydroxy-hexanoate (PHBHHx) membranes. In this study, PHBHHx membranes from three thin-film processes were used. PHBHHx membranes with different surface morphologies were prepared by phase inversion, electrospinning, and hot pressing. The morphologies of the PHBHHx membranes were investigated by scanning electron microscopy (SEM). Tooth germ cells were isolated from four-day-old Wistar rats. The cellular adhesion, proliferation and viability were determined by SEM, BrdU (5-bromo-2-deoxyuridine) and MTT (3-[4, 5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide; Thiazolyl blue) assay. In addition, the adherent behavior of tooth germ cells on various surface structures of PHBHHx was observed under a fluorescence microscope after staining of the cytoskeletal filamentous actin of the cells. It was found that cell compatibility of the PHBHHx membranes made from the phase inversion method (p-PHBHHx) was better than that of the other PHBHHx membranes. The results also revealed that tooth germ cells cultured on the PHBHHx membranes with porous surface structure were well spread relative to those on the fibrous structure of PHBHHx membranes. Therefore, PHBHHx membranes with a porous surface structure can encourage either cell adhesion or cell proliferation. PHBHHx membranes with a porous morphology satisfy biomaterial requirements for a scaffold for tooth regeneration.

AMOLED displays based on metal oxide film as active channel layer are fabricated. To achieve cost-competitive process in OLED manufacturing, solution-processed HIL, HTL and pixilated EML (RGB) layers followed by evaporation process for other layers are demonstrated in this work. Meanwhile, the AMOLED backplanes possessing low power consumption and high frequency were fabricated on metal oxide TFTs with high mobility (23.13 cm2/Vs) technology. A 14” qHD AMOLED in 79 ppi-resolution was realized with IGZO based active matrix panel.

The purpose of this study is to demonstrate pH-responsive chitosan is able to control cell behavior in response to small changes in environmental pH, which is at useful pH suitable for recovering cultured cells without additional enzymatic treatment and extensive washing steps. HeLa cells attached and spread well on chitosan at pH 6.99 and 7.20. When the pH was increased to 7.65, over 90% of cells would rapidly detached from chitosan surface within 1 h. Similarly, fibronectin adsorbed on chitosan at pH 7.20 also rapidly desorbed after increasing the medium pH. Most importantly and interestingly, medium pH adjustment could be facilitated by altering environment pCO(2). It was found over 80% of HeLa cells could be recovered from chitosan surface within 1 h and the viability of detached cells was more than 95% by transferring the culture plate from incubator to atmospheric condition. Additionally, chitosan substrate could effectively control attachment/detachment of various types of cells including cell lines HaCaT, H1299, NIH-3T3, and primary corneal fibroblasts, indicating the technology described here is easily reproducible and should be promising for controlling rapid fibronectin adsorption/desorption and cell attachment/detachment for tissue engineering applications.

A variable gene delivery system has been developed based on conjugating chitosan to biotin through a functionalized poly(ethylene glycol) (PEG) spacer, which can be used to further bind different molecules on the outer layer of a polymer/DNA complex by streptavidin (SA)–biotin linkage. In this study, TAT-conjugated SA was used as the model molecule to prove the conjugation function of the prepared complex. In addition, low-molecular-weight poly(ethyleneimine) (PEI) was added into the polymer/DNA complex to increase the transfection efficiency. The results of the luciferase assay show that the transfection efficiency of the prepared complex was significantly correlated with the amount of PEI and was further enhanced when TAT was conjugated to the complex by SA–biotin linkage. Considered to have negligible cytotoxic effects, the variable gene delivery complex prepared in this study would be of considerable potential as carriers for in vitro applications.

A novel cationic co-polymer was developed by grafting poly(ethylene glycol) (PEG) on guanidinylated polyallylamine (PAA) for gene delivery. Characterization of PEG-g-guanidinylated PAA/DNA complexes demonstrated that particle size increased and surface charge decreased with increasing the amount of PEG. The results of cytotoxicity assay proved that grafted PEG could effectively decrease the cytotoxicity of the complexes. In transfection efficiency assay, HeLa cells treated with PEG(2)-g-guanidinylated PAA (formed with 17.5 μmol guanidinylated PAA and 2 μmol PEG)/DNA (0.2 μg EGFP plasmid) complexes showed a very high level of EGFP expression. In conclusion, combination of guanidinylation and PEGylation could effectively decrease the cytotoxicity and significantly increase the transfection efficiency of PAA.

The application of techneuqe of assembling oligonucleotides (5'-C 10 A 20 -3') with binay polyethylene imine (PEI)/DNA complexes used to prepare a ternary anioic gene delivery system. Characterization of PEI/DNA/oligonucleotide complexes demonstrated that nanoparticles possessed the negative surface charge −50 mV and size of around 100–170 nm when the molar ratio of oligonucleotide/PEI exceeded 9. Compared with PEI/DNA complexes PEI/DNA/oligonucleotide complexes could completely resistant against erythrocyte agglutination because of anionic surface charge and would not disassociate during the process of forming ternary complexes. The oligonucleotide-coated PEI/DNA complexes exhibited high gene expression with low cytotoxicity in the living Hs68 cells (cell line) and fibroblast-like synoviocytes (primary cells), respectively. Additionally, the deposition of a layer of oligonucleotide onto the binary PEI/DNA complexes could prevent serum inhibition during transfection process. Therefore, the oligonucleotide-coated PEI/DNA complex seems to be a feasible approach to develop new anionic gene delivery systems.

For enterprises, customer relationships have been commonly recognized as a critical factor to succeed their business. Effective customer relationships could help enterprises deliver services to customers based on their needs, preferences, or past transactions. In this context, many discussions have already been presented where Consumer Support Systems (CSS) is most recently introduced that alleviates the shortcomings in other approaches by a 4-layer framework of collaborative mechanisms to support effective information/service provision between enterprises and customers. Since in CSS customers get used to participate in various communities to share or co-learn information about their experiences or requests on enterprises, a comprehensive structure for such information is therefore necessary for its easy sharing or co-learning among these customers. For this need and as a pristine way for knowledge-sharing by ontology, we present in this paper a method for the construction of an ontology that describes customer information with an easy understood structure. The method starts from the specification of the ontology based on the experiences of customers, through the browsing of their new ideas, and ends with the verification of its consistency. To illustrate, the method is applied in an exemplified application for travel arrangement.

In this study, we modified poly(ethylene-co-vinyl alcohol) (EVAL) membranes by the covalent bonding of diamines via epoxidation of surface hydroxyl groups of EVAL to analyze the effect of immobilized diamines with different carbon chain length on the cultured cerebellar granule neurons. Morphological studies showed that neurons seeded on the diamine-immobilized EVAL membrane were able to survive and regenerate with formation of an extensive neuritic network. Furthermore, cultured neurons showed that the presence of diamine with different carbon chain length was able to effectively regulate the neuron adhesion, migration, aggregation, and neurite growth pattern, but mediated neuronal activity with equal efficacy. The short-chain amine stimulated neuron migration, aggregation, and neurite fasciculation, whereas the long carbon chain diamine maintained single neuron distribution with the defasciculated feature of the neurite. Although it is known that positively charged amine molecules can interact directly with cell surface proteoglycans to mediate cell attachment, this study further demonstrated that the terminal primary amine with different carbon chain length is involved in mediating cell-substrate interaction to further regulate neuron aggregation and neurite fasciculation. This indicates a delicate interaction of neuron with the immobilized diamine molecules on the EVAL membrane surface. This work is encouraging because the diamine- immobilized EVAL membranes can be applied for the establishment of different neural culture systems useful for future investigations of neuron biology under in vitro conditions.

Ternary nanoparticles with negatively charged surface were prepared by coating single-stranded oligonucleotides (5'-C(10)A(20)-3') on histidine-conjugated polyallylamine (PAA-HIS)/DNA complexes for gene delivery. Characterization of PAA-HIS/DNA/oligonucleotide complexes demonstrated that nanoparticles possessed the negative surface charge -27 mV and size of around 100 nm when the molar ratio of oligonucleotide/PAA-HIS exceeded 1.5. The negatively charged oligonucleotide-coated PAA-HIS/DNA complexes could be entirely internalized by the living HeLa cells to exhibit high gene expression with low cytotoxicity and the resistance against erythrocyte agglutination and serum inhibition. Since the gene expression of PAA-HIS/DNA complexes was significantly inhibited by coating other polyanions and oligonucleotides, the ternary PAA-HIS/DNA/deoxyadenosine-rich oligonucleotide complexes were uptaken by specific receptor-mediated process. Additionally, the deposition of a layer of oligonucleotides onto the binary PAA-HIS/DNA complexes could effectively transfect various types of cells including HEK-293, HepG2 and Hs68 cells, indicating the technology of coating specific oligonucleotides on PAA-HIS/DNA complexes or other cationic binary DNA complexes might facilitate the use of nanoparticles for safe and efficient gene delivery and eventual therapy.

This paper investigates the degradation mechanism under self-heating stress for InGaZnO thin film transistor. The apparent positive threshold voltage (Vt) shift and on-current degradation indicate that the combination of trap states generation and electron trapping effect occur during stress. Furthermore, the asymmetric degradation behavior in the Id-Vg saturation measurement demonstrates that the trap states location is near the source side since the relative vertical electrical field is higher than drain side. Moreover, the Joule heating generated by self-heating operation can enhance electron trapping effect and cause larger Vt shift in comparison with the gate-bias stress.

This letter investigates asymmetrical degradation behavior induced by the self-heating effect in InGaZnO thin-film transistors. Both the surrounding oxide and other thermal insulating material, as well as the low thermal conductivity of the InGaZnO layer itself, cause the self-heating effect in InGaZnO thin-film transistors. The heated channel layer enhances threshold voltage shift, and the evolution of threshold voltage shift is found to be dominated by charge-trapping effect. Moreover, a non-uniform distribution of channel carrier concentration leads to an uneven temperature distribution through the InGaZnO active layer and results in the asymmetrical degradation behavior after self-heating operation.

Little information is known about the genetic mechanisms of the pathophysiology of varicose veins (VVs). The purpose of this study was to systematically explore the biological pathways of genes speculatively participating in VVs by microarray bioinformatics analysis methods. The results showed that 32 genes were upregulated and 74 genes were downregulated in VVs. Gene Ontology and relevant bioinformatics tools indicated that the functional categories in which 106 genes (2.8%; 106/3800) of the most frequent alteration belonged to were apoptosis and angiogenesis. The analysis of 20 VV tissue specimens demonstrated that genes involved in angiogenesis and apoptosis pathways had high rates of overexpression. In addition, we discovered that genes involved in the angiogenesis pathways included HSP90, ILK , and TGFB1 , and they played key roles in the development of VVs. This study demonstrated that the angiogenesis and apoptosis pathways may play an important role in the formation of VVs, but their molecular mechanisms need further investigation.

This research proposes an integrated framework for the use of textual and economic features to predict the exchange rate of the TWD (Taiwan dollar) against the RMB (Chinese Renminbi). The exchange rate is affected by the current economic situation and expectations for the future economic climate. Exchange rate forecasting studies focus mainly on overall economic indices and the actual exchange rate, but overlook the influence of news. This research considers both textual and economic factors and builds three basic prediction models, i.e. multiple linear regression (MLR), support vector regression (SVR), and Gaussian process regression (GPR) for the prediction of the RMB exchange rate. In addition to the three basic prediction models, this research uses ensemble learning and feature selection techniques to improve prediction performance. Our experiments demonstrate that textual features also play an important role in predicting the RMB exchange rate. The SVR model is shown to outperform the other models and the MLR model is shown to perform worst. The ensemble of three basic models performs better than its individual counterparts. Finally, the models which use feature selection techniques demonstrate improved results in general, and different feature selection techniques are shown to be more suitable for different prediction models. JEL classification numbers: D80, F31, F47. Keywords: Exchange rate prediction, Text mining, Ensemble learning, Time series forecasting.