Identification of Compounds that Selectively Stabilize Specific G‐Quadruplex Structures by Using a Thioflavin T‐Displacement Assay as a Tool

Small molecules are used in the G‐quadruplex (G4) research field in vivo and in vitro, and there are increasing demands for ligands that selectively stabilize different G4 structures. Thioflavin T (ThT) emits an enhanced fluorescence signal when binding to G4 structures. Herein, we show that ThT can be competitively displaced by the binding of small molecules to G4 structures and develop a ThT‐displacement high‐throughput screening assay to find novel and selective G4‐binding compounds. We screened approximately 28 000 compounds by using three different G4 structures and identified eight novel G4 binders. Analysis of the structural conformation and stability of the G4 structures in presence of these compounds demonstrated that the four compounds enhance the thermal stabilization of the structures without affecting their structural conformation. In addition, all four compounds also increased the G4‐structure block of DNA synthesis by Taq DNA polymerase. Also, two of these compounds showed selectivity between certain Schizosaccharomyces pombe G4 structures, thus suggesting that these compounds or their analogues can be used as selective tools for G4 DNA studies.     

Improvement of solar cell efficiency by applying Si3N4 nanopattern on glass substrate

A cylindrical Si₃N₄ nanopattern whose heights was 200 nm was fabricated on a glass substrate, and an aluminum-doped zinc oxide (AZO) layer was grown on the nanopatterned glass substrate. The nanopattern was applied to an amorphous silicon solar cell in order to increase the light-scattering effect, thus enhancing the efficiency of the solar cell. The reflectance of the solar cell on the Si₃N₄ nanopattern decreased and its absorption increased. Compared to a flat substrate, the short-circuit current density (J_sc) and conversion efficiency of a solar cell on the Si₃N₄ nanopatterned substrate were improved by 17.9% and 24.2%, respectively, as determined from solar simulator measurements.     

Corrosion inhibition of ammonium molybdate for AA6061 alloy in NaCl solution and its synergistic effect with calcium gluconate

The corrosion inhibition of ammonium heltamolybdate (AH) and calcium gluconate (CG) for AA6061 alloy in 3% NaCl solution was investigated by the electrochemical measurements. It indicates that AH inhibits the corrosion of AA6061 alloy and acts as an anodic inhibitor. Maximum inhibition efficiency reaches 74.3% at the concentration of 1 × 10^?4 mol.l^?1 AH. The results of the electrochemical studies reveal AH is physically adsorbed on the AA6061 alloy surface and the adsorption follows Langmuir isotherm. The combination of AH and CG enhances the inhibition efficiency to 95.9%. The enhanced inhibition is attributed to the promotion of AH adsorption by CG. The mixture of AH and CG is a mixed‐type inhibitor and renders the corrosion potential to more positive values. Copyright © 2011 John Wiley & Sons, Ltd.     

Isobaric expansion coefficient and isothermal compressibility for a finite-size ideal Fermi gas system

Due to quantum size effects (QSEs), the isobaric thermal expansion coefficient and isothermal compressibility well defined for macroscopic systems are invalid for finite-size systems. The two parameters are redefined and calculated for a finite-size ideal Fermi gas confined in a rectangular container. It is found that the isobaric thermal expansion coefficient and isothermal compressibility are generally anisotropic, i.e., they are generally different in different directions. Moreover, it is found the thermal expansion coefficient may be negative in some directions under the condition that the pressures in all directions are kept constant.     

Identification of radical structures on 1‐pentamethylbenzyl‐3‐ethylimidazoliumsilver(I)bromide and 1,3‐bis(pentamethylbenzyl)‐4,5‐dimethylbenzimidazoliumsilver(I)bromide exposed to gamma rays: an EPR study

1‐Pentamethylbenzyl‐3‐ethylimidazoliumsilver(I)bromide and 1,3‐bis(pentamethylbenzyl)‐4,5dimethylbenzimidazoliumsilver(I)bromide and their Ag⁺ complexes were synthesized and their polycrystal forms were produced by recrystallization in dichloromethane/Et₂O solvent system. Structural determinations were carried out by ¹H NMR and ¹³C NMR with a Varian 400 NMR system using tetramethylsilane as internal standard and CDCl₃ as solvent. The disappearance of acidic N‐heterocyclic carbene proton showed the formation of Ag(I) complexes. Also, elemental analyses were carried out. Electron paramagnetic resonance (EPR) measurements were performed to determine the formed radical structure on the samples irradiated at the room temperature for 72 h by using ⁶⁰Co‐source with dose rate of 0.680 kGy. The EPR measurements were carried out in the temperature range of 200 K–450 K. Identical radicals were determined on the irradiated compounds. It was observed that the shapes of the spectra of the samples were independent of the temperature but, the resonance line intensities changed linearly with the temperature. Also, it was detected that the free radical on the 1‐pentamethylbenzyl‐3‐ethylimidazoliumsilver(I)bromide is not stable compared to that on the 1,3‐bis(pentamethylbenzyl)‐4,5dimethylbenzimidazoliumsilver(I)bromide. Copyright © 2016 John Wiley & Sons, Ltd.     

Calibration Curve with Improved Limit of Detection for Cadmium in Soil: An Approach to Minimize the Matrix Effect in Laser-Induced Breakdown Spectroscopic Analysis

The present article describes a working or combined calibration curve in laser-induced breakdown spectroscopic analysis, which is the cumulative result of the calibration curves obtained from neutral and singly ionized atomic emission spectral lines. This working calibration curve reduces the effect of change in matrix between different zone soils and certified soil samples because it includes both the species' (neutral and singly ionized) concentration of the element of interest. The limit of detection using a working calibration curve is found better as compared to its constituent calibration curves (i.e., individual calibration curves). The quantitative results obtained using the working calibration curve is in better agreement with the result of inductively coupled plasma–atomic emission spectroscopy as compared to the result obtained using its constituent calibration curves.     

Temperature memory effect and its stability revealed via differential scanning calorimetry in ethylene‐vinyl acetate within glass transition range

In this article, we reveal the temperature memory effect (TME) in a commercial thermoplastic polymer, namely ethylene‐vinyl acetate (EVA), within its glass transition range via a series of differential scanning calorimeter (DSC) tests. In addition, we investigate the influence of heating holding time and also compare the observed TME in current study with that of shape memory alloys (SMAs). It is concluded that the TME via DSC (without any macroscopic shape change) is achievable within the glass transition range of a polymer. Conversely, although the observed TME shares the many similar features as those in SMAs, due to the nature of micro‐Brownian motion in the glass transition of polymers, the resulted TME is strongly affected by the heating holding time. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1731–1737     

Periodic solutions to a class of biological diffusion models with hysteresis effect

This paper is concerned with a class of biological models which consists of a nonlinear diffusion equation and a hysteresis operator describing the relationship between some variables of the equations. By the viscosity approach, we show the existence of periodic solutions of the problem under consideration. More precisely, with the help of the subdifferential operator theory and Leray–Schauder theorem, we show the existence of periodic solutions to the approximation problem and then obtain the solution of the original problem by using a passage-to-limit procedure.     

硼对第二代镍基单晶高温合金显微组织的影响

硼(B)是强化镍基单晶合金小角度晶界的重要微量元素,但目前关于B对镍基单晶合金显微组织影响的系统报道非常有限。通过对3种不同B含量(质量分数分别为0、0.01%、0.02%)的第二代镍基单晶合金DD11铸态及热处理态组织定量表征,研究了B对相转变温度、(γ+γ′)共晶组织、硼化物的影响。结果表明:B显著降低合金的固液相线,提高铸态共晶组织体积分数;0.01%B的加入,合金中未出现M3B2型硼化物相;而0.02%B的加入,显著促进了骨架状硼化物的形成,降低合金初熔点,引起残余共晶含量的大幅度提高;骨架状硼化物吸收较多的Cr、Mo和W等元素,降低合金的固溶强化效果,可导致单晶合金基体的蠕变性能大幅度降低。研究结果对认识单晶合金中微量元素B的作用机理及优化B成分范围具有理论指导意义。     

Oxygen consumption and chemisorption in low-temperature oxidation of sub-bituminous pulverized coal

Studying the effect of oxygen in coal oxidation is very important for understanding and controlling coal spontaneous combustion. However, the oxygen effect is not very easy to determine clearly due to the large effect of heat source on coal oxidation in temperature rising experiments. Here, focused on sub-bituminous coal, the oxygen effect was separated from coal oxidation by continuously measuring FTIR spectra of coal with respect to varying temperatures and under oxygen and nitrogen. The active groups’ real-time changes of coal oxidation, thermal treatment and oxygen effect were measured. The carboxylic ester and carboxyl units are the main functional groups that increase with temperatures increasing under oxygen and nitrogen, while the other functional groups decrease in quantity. The oxygen effect promoted the consumption of aliphatic hydrocarbons and hydroxyl groups and also promoted the formation of oxygen-containing groups (except hydroxyl). Four characteristic temperature stages involved in the oxygen effect and their key functional groups were identified. Simultaneously, the relationship of oxygen consumption and chemisorption in oxygen effect was analyzed. The starting temperature of oxygen chemisorption is between 50 and 60°C. The maximum contribution of oxygen effect was observed in methyl and methylene groups. These results are important for chemical control of coal spontaneous combustion. The oxidation of aliphatic hydrocarbon should be controlled before oxygen chemisorption. The value of oxygen consumption between 70 and 80°C can be measured accurately due to the constant chemisorption rate, which help to identify the tendency for spontaneous combustion. These results will help in better understanding of the reaction mechanism of coal oxidation, especially the oxygen effect.