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Liquid crystals have been used as the stationary phase in gas chromatography since the 1960s [1-3]. Much research has been devoted to their analytical performance in many applications, particularly for [...], Liquid crystals are used as the stationary phase in gas chromatography to separate close-boiling isomers. In this paper, a new nematic liquid crystal containing oxadiazole was prepared by condensation of the amino group of 4-(5-(ethylthio)-1,3,4-oxadiazole-2-yl)aniline and the aldehyde group ofp-methoxybenzaldehyde. The compound was characterized by NMR, IR, X-ray diffraction, polarized light microscopy, and differential scanning calorimetry. The liquid crystal was used as the stationary phase in gas chromatography, and the nematic phase separated a variety of isomers, such as benzene derivatives, ionone, and citral. Keywords: liquid crystal, synthesis, characterization, stationary phase, gas chromatography DOI: 10.1134/S1061934816050026

Heavy metals have a detrimental effect on human health and environment if not managed efficiently. For this reason, industrial wastewaters are strictly regulated and have to be treated before being discharged. The efficiency of bipolar reactor with recirculation flow mode and aluminum electrode in removing copper and nickel from high concentrated solution by electrocoagulation was examined. The experimental design (Box-Behnken) was employed to investigate the effects of different operating conditions and their interactions on the removal: electrolysis time (t, min), current density (i, A/m²), pH, and initial concentration (Ci, mg/L). The results showed a high removal rate (97.42% for copper, and 100% for nickel), and also a good correlation between the values measured and those predicted by the Box-Behnken experimental design, for the removal of copper (R² = 0.94, P value = 0.0003) as well as of nickel (R² = 0.95, P value = 0.0001). [ABSTRACT FROM AUTHOR]

The objective of this research paper is to study the competitive adsorption of cadmium and nickel ions, where the effect of experimental factors such as pH solution, temperature, contact time and initial concentration of metals ions have been studied. The test of isothermal models indicated that the Freundlich model showed more explanation for this competitive adsorption of the ions studied. In addition, the study of thermodynamic parameters has been carried out. The results also showed that the adsorbent have a greater affinity for cadmium ions than nickel ions under optimum experimental conditions. [ABSTRACT FROM AUTHOR]

This study consists of evaluating the biosorption on a local material, palm stems from the Laghouat region. In order to optimize this process, several parameters such as: pH, contact time, initial dye concentration and ionic strength were also studied. Monitoring of the kinetics of direct absorption of methyl orange by palm stems and the isothermal study. The results of the batch biosorption tests confirmed the ability of this material to adsorb the studied dye with an equilibrium time of 120 min at pH 4. The modeling shows that the biosorption of the elements considered takes place in a monolayer according to the Langmuir isotherm with a maximum adsorption quantity of methyl orange is estimated at 8.67 mg/g under the optimal conditions obtained. [ABSTRACT FROM AUTHOR]

The electric field distribution is one of the main factors governing the long-term reliability of high voltage composite insulators. However, under severe pollution conditions, electric field stresses, when exceeding thresholds and applying for long periods, could lead to degradation and deterioration of the housing materials and, therefore, to failures of the composite insulators. This paper is intended to improve the distributions of the electric field and potential by minimizing the corona ring on a 400 kV AC transmission line composite insulator. The performances of three powerful multi-objective meta-heuristic algorithms, namely Ant Lion Optimizer (MOALO), Particle Swarm Optimizer (MOPSO), and non-dominated sorting genetic algorithm (NSGA-II) are established to achieve this goal. First, variations of electrical fields on the critical parts of the string are obtained using three-dimensional finite element method (FEM) software. Then, three objective functions are developed to establish the relationships between the electric field and the guard ring parameters. Finally, the optimization parameters consist of diameter, tube diameter, and installation height of the corona ring. The obtained results confirm the effectiveness of the three algorithms; the MOLAO is the better in terms of computing time and solution quality.

Background: Osteoprotegerin (OPG), a glycoprotein of the tumour necrosis factor (TNF) superfamily, is one of the main biomarkers for vascular calcification., Aim: We aimed to evaluate the association between serum OPG levels and extent of coronary lesions in patients with acute myocardial infarction (MI)., Methods: Consecutive patients hospitalized for an acute MI who underwent coronary angiography were included. SYNTAX score was calculated to assess the severity of coronary artery disease. The population was analysed in low (5 (3-6)), medium (11 (9-13)) and high (20 (18-23)) tertiles of SYNTAX score., Results: Among the 378 patients included, there was a gradual increase in age, rate of diabetes, anterior wall location, and a reduction in left ventricular ejection fraction across the SYNTAX tertiles. OPG levels significantly increased across the tertiles (962 (782-1497), 1240 (870-1707), and 1464 (1011-2129) pg/mL, respectively ( p < 0.001)). In multivariate analysis, OPG [OR(CI95%): 2.10 (1.29-3.49) 0.003], were associated with the high SYNTAX group, beyond hypercholesterolemia, CV history and reduced glomerular filtration rate., Conclusion: We found an association between OPG levels and coronary lesions complexity patients with acute MI.

The new acylated indole alkaloid glucoside indole-3-carboxylic acid-(6'- O -caffeoyl)-β-D-glucoside 1 has been isolated from the ethyl acetate (EtOAC) extract of Saccocalyx satureioides Coss. & Dur. (Lamiaceae) together with eight known secondary metabolites 2 - 9 . Two indoles 2 and 3 , five methylated flavone aglycones 4-8 and one monoterpene glucoside 9 were reported for the first time in the genus Saccocalyx. The structural elucidation of these compounds was accomplished by spectroscopic methods including 1 D ( 1 H and 13 C) and 2 D (COSY, HSQC and HMBC) NMR techniques, and mass spectrometry, and by comparison with literature data. Light petroleum, EtOAc, chloroform and n -butanol ( n -BuOH) extracts of S. Satureioides were screened for their antioxidant activity using DPPH radical scavenging and β-carotene bleaching methods. The antibacterial activity of these extracts indicates that n -BuOH and EtOAc extracts possess the strongest activity.