Characteristics of Ventricular Electrophysiological Substrates in Metabolic Mice Treated with Empagliflozin

Empagliflozin (EMPA) is a sodium–glucose transporter 2 (SGLT2) inhibitor that functions as a new-generation glucose-lowering agent and has been proven to be beneficial for patients with cardiovascular diseases. However, the possible benefits and mechanisms of its antiarrhythmic effects in cardiac tissue have not yet been reported. In this study, we elucidated the possible antiarrhythmic effects and mechanisms of EMPA treatment in cardiac tissues of metabolic syndrome (MS) mice. A total of 20 C57BL/6J mice (age: 8 weeks) were divided into four groups: (1) control group, mice fed a standard chow for 16 weeks; (2) MS group, mice fed a high-fat diet for 16 weeks; (3) EMPA group, mice fed a high-fat diet for 12 weeks and administered EMPA at 10 mg/kg daily for the following 4 weeks; and (4) glibenclamide (GLI) group, mice fed a high-fat diet for 12 weeks and administered GLI at 0.6 mg/kg daily for the following 4 weeks. All mice were sacrificed after 16 weeks of feeding. The parameters of electrocardiography (ECG), echocardiography, and the effective refractory period (ERP) of the left ventricle were recorded. The histological characteristics of cardiac tissue, including connexin (Cx) expression and fibrotic areas, were also evaluated. Compared with the MS group, the ECG QT interval in the EMPA group was significantly shorter (57.06 ± 3.43 ms vs. 50.00 ± 2.62 ms, p = 0.011). The ERP of the left ventricle was also significantly shorter in the EMPA group than that in the GLI group (20.00 ± 10.00 ms vs. 60.00 ± 10.00 ms, p = 0.001). The expression of Cx40 and Cx43 in ventricular tissue was significantly lower in the MS group than in the control group. However, the downregulation of Cx40 and Cx43 was significantly attenuated in the EMPA group compared with the MS and GLI groups. The fibrotic areas of ventricular tissue were also fewer in the EMPA group than that in the MS group. In this study, the ECG QT interval in the EMPA group was shorter than that in the MS group. Compared with the MS group, the EMPA group exhibited significant attenuation of downregulated connexin expression and significantly fewer fibrotic areas in ventricles. These results may provide evidence of possible antiarrhythmic effects of EMPA.     

Electroactive PI sphere generated by electrospraying

In this study, electroactive polyimide microspheres (EPSs) based on conjugating segments of electroactive aminocapped aniline trimer as diamine and 4,4′‐(4,4′‐isopropylidenediphenoxy)‐bis(phthalic anhydride) as dianhydride were successfully prepared by electrospraying technology and characterized by time of flight mass spectroscopy, ¹H‐NMR, Fourier transform infrared spectroscopy and cyclic voltammetry. The prepared electroactive polyimide was then dissolved in a suitable organic solvent (N,N‐dimethylformamide; N‐methyl‐2‐pyrrolidone) followed by electrospraying treatment under four different operational parameters (i.e. solution concentration, applied voltage, feeding rate and deposition distance) to give EPSs of various diameters. Moreover, EPSs deposited on the Pt electrode were tested in a 1.0 mol L^?1 H₂SO₄ aqueous solution by cyclic voltammetry which showed an obvious redox peak similar to polyaniline. Copyright © 2011 Society of Chemical Industry     

Effect of TiO2 nanotubes with TiCl4 treatment on the photoelectrode of dye-sensitized solar cells

In this study, we used the electrochemical anodization to prepare TiO₂ nanotube arrays and applied them on the photoelectrode of dye-sensitized solar cells. In the field emission scanning electron microscopy analysis, the lengths of TiO₂ nanotube arrays prepared by electrochemical anodization can be obtained with approximately 10 to 30 μm. After titanium tetrachloride (TiCl₄) treatment, the walls of TiO₂ nanotubes were coated with TiO₂ nanoparticles. XRD patterns showed that the oxygen-annealed TiO₂ nanotubes have a better anatase phase. The conversion efficiency with different lengths of TiO₂ nanotube photoelectrodes is 3.21%, 4.35%, and 4.34% with 10, 20, and 30 μm, respectively. After TiCl₄ treatment, the efficiency of TiO₂ nanotube photoelectrode for dye-sensitized solar cell can be improved up to 6.58%. In the analysis of electrochemical impedance spectroscopy, the value of R_k (charge transfer resistance related to recombination of electrons) decreases from 26.1 to 17.4 Ω when TiO₂ nanotubes were treated with TiCl₄. These results indicate that TiO₂ nanotubes treated with TiCl₄ can increase the surface area of TiO₂ nanotubes, resulting in the increase of dye adsorption and have great help for the increase of the conversion efficiency of DSSCs.     

Spatial?temporal content-adaptive deinterlacing algorithm

An algorithm, which adapts to an appropriate interpolation technique for high-quality deinterlacing based on the spatial?temporal spectral and edge-oriented features of local video contents, is introduced. This algorithm employs a spectrum-adaptive vertical?temporal filter to deal with generic video scenes, and adopts a texture-adaptive edge-based line-averaging interpolation with an edge-consistency check to interpolate moving edges with high efficiency. This deinterlacing algorithm likewise incorporates an economical recursive stationary-pixel detection scheme with a field-averaging filter to effectively interpolate stationary video scenes. Because of the precise selection of the interpolation technique for versatile video contents, the proposed algorithm provides not only better objective peak signal-to-noise ratio, but also results in more impressive subjective visual quality when compared with other non-motion compensated deinterlacing approaches.     

A two-stage three-machine assembly scheduling problem with a position-based learning effect

The two-stage assembly scheduling problem has attracted increasing research attention. In many such problems, job processing times are commonly assumed to be fixed. However, this assumption does not hold in many real production situations. In fact, processing times usually decrease steadily when the same task is performed repeatedly. Therefore, in this study, we investigated a two-stage assembly position-based learning scheduling problem with two machines in the first stage and an assembly machine in the second stage. The objective was to complete all jobs as soon as possible (or to minimise the makespan, implying that the system can perform better and efficient task planning with limited resources). Because this problem is NP-hard, we derived some dominance relations and a lower bound for the branch-and-bound method for finding the optimal solution. We also propose three heuristics, three versions of the simulated annealing (SA) algorithm, and three versions of cloud theory-based simulated annealing algorithm for determining near-optimal solutions. Finally, we report the performance levels of the proposed algorithms.     

Infrared brazing of Fe3Al intermetallic compound using gold-based braze alloy

Infrared-brazing Fe₃Al with Au–44Cu as filler metal has been investigated. The brazed joint consists mainly of a β-phase, Au_8 − x Cu_4 + x Al₄, caused by the dissolution of Al from Fe₃Al substrate into the braze alloy. The depletion of Al from Fe₃Al substrate results in the formation of a layer of β-phase particles dispersed in the Fe-rich phase. The highest shear strength for AuCu filler is 327 MPa for specimens infrared brazed at 880°C for 180 s. The brazed joint is mainly fractured along the central β-phase in which the fractograph exhibits quasi-cleavage with dimples. Increasing the brazing time or temperature will deteriorate the bonding strength of the joint, and the fracture mode is prone to cleavage of brittle fracture. Au–44Cu filler demonstrates a great potential for bonding Fe₃Al intermetallic compound.     

Advanced antistatic/anticorrosion coatings prepared from polystyrene composites incorporating dodecylbenzenesulfonic acid‐doped SiO2@polyaniline core–shell microspheres

We present the preparation of advanced antistatic and anticorrosion coatings of polystyrene (PS) incorporating a suitable amount of dodecylbenzenesulfonic acid (DBSA)‐doped SiO₂@polyaniline (SP) core–shell microspheres. First, aniline‐anchored SiO₂ (AS) microspheres that were about 850 nm in diameter were synthesized using the conventional base‐catalyzed sol–gel process with tetraethyl orthosilicate in the presence of N‐[3‐(trimethoxysilyl)propyl]aniline. SP core–shell microspheres were then synthesized by chemical oxidative polymerization of aniline monomers with ammonium persulfate as an oxidizing agent in the presence of the AS microspheres. The polyaniline shell thickness of the as‐prepared core–shell microspheres was estimated to be about 120 nm. The AS and SP microspheres were further characterized using Fourier transform infrared spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy. The as‐synthesized DBSA‐doped SP core–shell microspheres were then blended into PS using N‐methyl‐2‐pyrrolidone as solvent and then cast onto a cold–rolled steel (CRS) electrode to obtain antistatic and anticorrosion coatings with a thickness of about 10 µm. The corrosion protection efficiency of the as‐prepared coating materials on the CRS electrode was investigated using a series of systematic electrochemical measurements under saline conditions. The enhanced corrosion protection ability of the PS/SP composite coatings may be attributed to the formation of a dense passive metal oxide layer induced by the redox catalytic effect of the polyaniline shell of the as‐synthesized core–shell microspheres, as evidenced by electron spectroscopy for chemical analysis and SEM observations. Moreover, the PS composite coating containing 10 wt% of the SP core–shell microspheres showed an electrical resistance of about 3.65 × 10⁹Ω cm^?2, which meets the requirements for antistatic applications. Copyright © 2012 Society of Chemical Industry     

An improved method for forecasting enrollments based on fuzzy time series and particle swarm optimization

Many forecasting models based on the concept of fuzzy time series have been proposed in the past decades. Two main factors, which are the lengths of intervals and the content of forecast rules, impact the forecasted accuracy of the models. How to find the proper content of the main factors to improve the forecasted accuracy has become an interesting research topic. Some forecasting models, which combined heuristic methods or evolutionary algorithms (such as genetic algorithms and simulated annealing) with the fuzzy time series, have been proposed but their results are not satisfied. In this paper, we use the particle swarm optimization to find the proper content of the main factors. A new hybrid forecasting model which combined particle swarm optimization with fuzzy time series is proposed to improve the forecasted accuracy. The experimental results of forecasting enrollments of students of the University of Alabama show that the new model is better than any existing models, and it can get better quality solutions based on the first-order and the high-order fuzzy time series, respectively.     

A hybrid forecasting model for enrollments based on aggregated fuzzy time series and particle swarm optimization

In this paper, a new forecasting model based on two computational methods, fuzzy time series and particle swarm optimization, is presented for academic enrollments. Most of fuzzy time series forecasting methods are based on modeling the global nature of the series behavior in the past data. To improve forecasting accuracy of fuzzy time series, the global information of fuzzy logical relationships is aggregated with the local information of latest fuzzy fluctuation to find the forecasting value in fuzzy time series. After that, a new forecasting model based on fuzzy time series and particle swarm optimization is developed to adjust the lengths of intervals in the universe of discourse. From the empirical study of forecasting enrollments of students of the University of Alabama, the experimental results show that the proposed model gets lower forecasting errors than those of other existing models including both training and testing phases.     

The Novel Additive 1‐Naphthalenethiol Opens a New Processing Route to Efficiency‐Enhanced Polymer Solar Cells

Polymer solar cells (PSCs) based on fullerene derivatives often require additives to optimize active layer morphology. Here, the novel additive 1‐naphthalenethiol (SH‐na) is proposed for processing the PSC active layer of PTB7:PC₇₁BM. Spin‐casting with SH‐na as additive achieves a power conversion efficiency (PCE) of 7.3%, compared to 6.7% for preparations containing the conventional 1,8‐diiodooctane additive. Dipping of the active layer into a methanol solution of critical SH‐na concentration increases the PCE further to 8.75%. This is mainly due to an improved open‐circuit voltage (from 0.72 to 0.79 V) together with a high achieved fill factor of 0.70. The improved PCE is correlated to the morphology optimization according to measurements of grazing incidence small/wide‐angle X‐ray scattering, neutron reflectivity, atomic force microscopy, Fourier transform infrared spectroscopy, and X‐ray photoelectron spectroscopy. The integrated results suggest that the halogen‐free additive SH‐na can form hydrogen bonds with both PTB7 and PC₇₁BM, resulting in substantially improved PTB7 crystallization and multi‐length‐scale PC₇₁BM dispersion for appropriate aggregation and networks. The subsequent dipping treatment with SH‐na further modifies the active layer morphology for a more PC₇₁BM‐enriched surface and better PC₇₁BM networks in the bulk film for an optimized electron‐to‐hole mobility ratio of 2.04, hence resulting in improved device performance.