Rutin Modulates MAPK Pathway Differently from Quercetin in Angiotensin II-Induced H9c2 Cardiomyocyte Hypertrophy

Rutin is a flavonoid with antioxidant property. It has been shown to exert cardioprotection against cardiomyocyte hypertrophy. However, studies regarding its antihypertrophic property are still lacking, whether it demonstrates similar antihypertrophic effect to its metabolite, quercetin. Hence, this study aimed to investigate the effects of both flavonoids on oxidative stress and mitogen-activated protein kinase (MAPK) pathway in H9c2 cardiomyocytes that were exposed to angiotensin II (Ang II) to induce hypertrophy. Cardiomyocytes were exposed to Ang II (600 nM) with or without quercetin (331 μM) or rutin (50 μM) for 24 h. A group given vehicle served as the control. The concentration of the flavonoids was chosen based on the reported effective concentration to reduce cell hypertrophy or cardiac injury in H9c2 cells. Exposure to Ang II increased cell surface area, intracellular superoxide anion level, NADPH oxidase and inducible nitric oxide synthase activities, and reduced cellular superoxide dismutase activity and nitrite level, which were similarly reversed by both rutin and quercetin. Rutin had no significant effects on phosphorylated proteins of extracellular signal-related kinases (ERK1/2) and p38 but downregulated phosphorylated c-Jun N-terminal kinases (JNK1/2), which were induced by Ang II. Quercetin, on the other hand, had significantly downregulated the phosphorylated proteins of ERK1/2, p38, and JNK1/2. The quercetin inhibitory effect on JNK1/2 was stronger than the rutin. In conclusion, both flavonoids afford similar protective effects against Ang II-induced cardiomyocyte hypertrophy, but they differently modulate MAPK pathway.     

Hydrogels of Thermoreversible Comb‐Polymers Exhibit Increased Resistance for Dissolution

The N‐isopropylacrylamide (NiPAM) polymers exhibit thermoreversible properties in aqueous solutions. The resiliency of NiPAM hydrogels is believed to influence the outcome when the polymers are utilized in biomedical applications. To determine the influence of polymer architecture on hydrogel resiliency, polymers of NiPAM, methyl methacrylate (MMA) and acrylic acid were synthesized as random polymers and as comb polymers, where MMA was incorporated as side‐chains. Random polymers exhibited a Lower Critical Solution Temperature (LCST) that decreased in proportion to MMA content in polymers. The LCST of comb polymers was not dependent on MMA content or the length of MMA side‐chain (between 3.0 and 10.1 kD). Whereas low molecular weight (～100 kD) random polymers did not form intact gels, comb‐polymers of equivalent molecular weight were capable of forming intact gels. Gel resiliency, as determined by propensity of hydrogels to dissolve upon cooling, was improved when the molecular weight of comb‐polymers was increased but the length of the MMA side‐branch did not influence the gel resiliency. We conclude that hydrogel dissolution was dependent on polymer architecture as well as the polymer molecular weight.     

Vibration characteristics of laminated composite beams with magnetorheological layer using layerwise theory

Vibration characteristics of laminated composite beams with magnetorheological (MR) layer are investigated using layerwise theory. In most studies, shear strain across the thickness of MR layer has been considered as a constant value, which does not precisely describe the shear strain. In this study, layerwise theory is employed to develop a finite element formulation to investigate MR-laminated beams. Experimental tests under different magnetic fields are carried out to verify the numerical results. Layerwise numerical results are compared with the experimental results and other theories. An empirical expression for complex shear modulus is presented. The effects of MR layer thickness on vibration of MR-laminated beams are examined.     

Robust brain MRI denoising and segmentation using enhanced non‐local means algorithm

Image denoising is an integral component of many practical medical systems. Non‐local means (NLM) is an effective method for image denoising which exploits the inherent structural redundancy present in images. Improved adaptive non‐local means (IANLM) is an improved variant of classical NLM based on a robust threshold criterion. In this paper, we have proposed an enhanced non‐local means (ENLM) algorithm, for application to brain MRI, by introducing several extensions to the IANLM algorithm. First, a Rician bias correction method is applied for adapting the IANLM algorithm to Rician noise in MR images. Second, a selective median filtering procedure based on fuzzy c‐means algorithm is proposed as a postprocessing step, in order to further improve the quality of IANLM‐filtered image. Third, different parameters of the proposed ENLM algorithm are optimized for application to brain MR images. Different variants of the proposed algorithm have been presented in order to investigate the influence of the proposed modifications. The proposed variants have been validated on both T1‐weighted (T1‐w) and T2‐weighted (T2‐w) simulated and real brain MRI. Compared with other denoising methods, superior quantitative and qualitative denoising results have been obtained for the proposed algorithm. Additionally, the proposed algorithm has been applied to T2‐weighted brain MRI with multiple sclerosis lesion to show its superior capability of preserving pathologically significant information. Finally, impact of the proposed algorithm has been tested on segmentation of brain MRI. Quantitative and qualitative segmentation results verify that the proposed algorithm based segmentation is better compared with segmentation produced by other contemporary techniques.     

Isolation enhancement of rectangular dielectric resonator antennas using wideband double slit complementary split ring resonators

A wideband epsilon‐negative structure is employed as one‐layer and two‐layer isolators to reduce mutual coupling in multiple‐input multiple‐output systems composed of two E‐coupled rectangular dielectric resonator antennas. The proposed unit cell with ?15 dB bandwidth for S₂₁ extending from 1970 to 3317 MHz, is a double slit complementary split ring resonator etched on the ground plane of a stripline. Each layer is composed of a 2 × 3 array of the suggested unit cell. Reduction in isolation of more than 11 dB for the one‐layer case and higher than 20 dB for the two‐layer case are measured within the frequency range of 2.604 to 2.64 GHz which includes WiMAX. The highest isolation level of 36 dB is realized at 2.868 GHz. The impedance matching, gain, radiation efficiency, and envelope correlation are improved compared to the original case. A prototype is designed, fabricated, and tested. Simulation data and measurement results are in good agreement.     

Multifractality in fidelity sequences of optimized Toffoli gates

We analyze the multifractality in the fidelity sequences of several engineered Toffoli gates. Using quantum control methods, we consider several optimization problems whose global solutions realize the gate in a chain of three qubits with XY Heisenberg interaction. Applying a minimum number of control pulses assuring a fidelity above 99 % in the ideal case, we design stable gates that are less sensitive to variations in the interqubits couplings. The most stable gate has the fidelity above 91 % with variations about 0.1 %, for up to 10 % variation in the nominal couplings. We perturb the system by introducing a single source of 1 / f noise that affects all the couplings. In order to quantify the performance of the proposed optimized gates, we calculate the fidelity of a large set of optimized gates under prescribed levels of coupling perturbation. Then, we run multifractal analysis on the sequence of attained fidelities. This way, gate performance can be assessed beyond mere average results, since the chosen multifractality measure (the width of the multifractal spectrum) encapsulates into a single performance indicator the spread of fidelity values around the mean and the presence of outliers. The higher the value of the performance indicator the more concentrated around the mean the fidelity values are and rarer is the occurrence of outliers. The results of the multifractal analysis on the fidelity sequences demonstrate the effectiveness of the proposed optimized gate implementations, in the sense they are rendered less sensitive to variations in the interqubits coupling strengths.     

The impact of growth, energy and financial development on the environment in China: A cointegration analysis

This article aims to investigate the impact of financial development, economic growth and energy consumption on environmental pollution in China from 1953 to 2006 using the Autoregressive Distributed Lag (ARDL) bounds testing procedure. The main objective is to examine the long run equilibrium relationship between financial development and environmental pollution. The results of the analysis reveal a negative sign for the coefficient of financial development, suggesting that financial development in China has not taken place at the expense of environmental pollution. On the contrary, it is found that financial development has led to a decrease in environmental pollution. It is concluded that carbon emissions are mainly determined by income, energy consumption and trade openness in the long run. Moreover, the findings confirm the existence of an Environmental Kuznets Curve in the case of China.     

Improvements in hydrogen production from methane dry reforming on filament-shaped mesoporous alumina-supported cobalt nanocatalyst

The mesoporous gamma-alumina (γ-Al₂O₃) synthesized via evaporation-induced self-assembly method (EISA) using inorganic salt, Al(NO₃)₃·9H₂O precursor and water-ethanol solvent mixture was implemented as a support for Co catalyst in methane dry reforming at 973–1073 K under 1 atm. The γ-Al₂O₃ support possessed filament-shaped morphology with surface area of 173.4 m² g^?1 and cobalt nanoparticles were successfully dispersed on support with small crystallite size of 7.8 nm. The stability of 10%Co/Al₂O₃ was evident for CH₄ and CO₂ conversions at 1023 and 1073 K. CH₄ conversion could reach to 76.2% while 81.6% was observed for CO₂ conversion at 1073 K. Although graphitic and amorphous carbons were unavoidably formed on used catalyst, 10%Co/Al₂O₃ exhibited an outstanding performance comparable to noble metals with the desired ratio of H₂/CO for downstream Fischer-Tropsch process.