Spectrofluorometric and Molecular Docking Studies on the Binding of Curcumenol and Curcumenone to Human Serum Albumin

Curcumenol and curcumenone are two major constituents of the plants of medicinally important genus of Curcuma, and often govern the pharmacological effect of these plant extracts. These two compounds, isolated from C. zedoaria rhizomes were studied for their binding to human serum albumin (HSA) using the fluorescence quench titration method. Molecular docking was also performed to get a more detailed insight into their interaction with HSA at the binding site. Additions of these sesquiterpenes to HSA produced significant fluorescence quenching and blue shifts in the emission spectra of HSA. Analysis of the fluorescence data pointed toward moderate binding affinity between the ligands and HSA, with curcumenone showing a relatively higher binding constant (2.46 × 10⁵ M⁻¹) in comparison to curcumenol (1.97 × 10⁴ M⁻¹). Cluster analyses revealed that site I is the preferred binding site for both molecules with a minimum binding energy of −6.77 kcal·mol⁻¹. However, binding of these two molecules to site II cannot be ruled out as the binding energies were found to be −5.72 and −5.74 kcal·mol⁻¹ for curcumenol and curcumenone, respectively. The interactions of both ligands with HSA involved hydrophobic interactions as well as hydrogen bonding.     

Smartphone-based colorimetric determination of sulfadiazine and sulfasalazine in pharmaceutical and veterinary formulations

A novel, simple, accurate, and low-cost colorimetric device based on an Android smartphone was developed for sulfonamide determination. A software program was developed to be used for analyzing the samples. Various parameters for digital colorimetric detection were investigated and optimized, such as the volume of the sample drop, the type of sample holder, the distance from the mobile phone camera to the sample holder, and the effect of ambient light. From the optimized conditions, a calibration curve was created by the intensity of blue channel for sulfonamides for the concentration range of 0.5–2.5?µg?mL^?1 with good linearity and a regression coefficient (R²) of 0.996. The results obtained by the smartphone method were compared with a spectrophotometric procedure at the 95% confidence level (n?=?3). Both methods correlated well with a regression coefficient (R²) of 0.997. The limit of detection of both methods was equal to 0.11?µg?mL^?1. The developed smartphone system was successfully used for the determination of sulfonamides in pharmaceutical and veterinary formulations with recoveries of 102 and 98.7%, respectively. The developed method provides good accuracy (relative error <5%) and precision (relative standard deviation <7%) and offers simple, convenient, rapid, and inexpensive determination of sulfonamides.     

Corrosion behaviour of two stainless steels and a chromium cast iron in phosphoric acid contaminated with S2− ions

Various impurities such as Cl^–, F^–, SO ₄ ^2– and S^2– contained in natural phosphates or introduced by enrichment processes, lead to many corrosion problems in equipment during the production of phosphoric acid by a wet process. Little is known about the action of S^2– ions in acidic media. In an attemptto investigate the mechanism of action of S^2– ions on stainless steels, the corrosion behaviour of three types of steel 904 L (X1NiCrMoCu25-20-5), 316 L (X2CrNiMo17-12-2) and cast iron containing 32wt % Cr in industrial phosphoric acid contaminated with S^2– ions was studied, using polarization curve analysis. The characterization of the corrosion products formed on the sample surface has enabled the production of a hypothesis on the corrosion and depassivation mechanisms of steels in these media. The effect of copper and molybdenum on the corrosion resistance of the studied materials in phosphoric acid contaminated by S^2– ions is noted and discussed in detail.     

Common weaving approach in mainstream languages for software security hardening

In this paper, we propose a novel aspect-oriented approach based on GIMPLE, a language-independent and a tree-based representation generated by the GNU Compiler Collection (GCC), for the systemization of application security hardening. The security solutions are woven into GIMPLE representations in a systematic way, eliminating the need for manual hardening that might generate a considerable number of errors. To achieve this goal, we present a formal specification for GIMPLE weaving and the implementation strategies of the proposed weaving semantics. Syntax for a common aspect-oriented language that is abstract and multi-language support together with syntax for a core set for GIMPLE constructs are presented to express the weaving semantics. GIMPLE weaving accompanied by a common aspect-oriented language (1) allows security experts providing security solutions using this common language, (2) lets developers focus on the main functionality of programs by relieving them from the burden of security issues, (3) unifies the matching and the weaving processes for mainstream languages, and (4) facilitates introducing new security features in AOP languages. We handle the correctness and the completeness of GIMPLE weaving in two different ways. In the first approach, we prove them according to the rules and algorithms provided in this paper. In the second approach, we accommodate Kniesel's discipline that ensures that security solutions specified by our approach are applied at all and only the required points in source code, taking into consideration weaving interactions and interferences. Finally, we explore the viability and the relevance of our propositions by applying the defined approach for systematic security hardening to develop case studies.     

Effects of Fifth-Instar Volatiles on Sexual Maturation of Adult Desert Locust Schistocerca gregaria

The effect of the presence of gregarious fifth-instar nymphs on the sexual maturation of newly molted gregarious immature adult males and females of the desert locust S. gregaria was investigated by monitoring color changes (yellowing of body), sexual activity, aggregation–maturation pheromone titers (as measured by phenylacetonitrile levels in males), oocyte length, and oviposition time. Maturation was significantly delayed in adults that were reared together with fifth-instar nymphs (visual, tactile, and chemical signals present) with respect to all parameters measured. Male and female nymphs were equally effective in inducing this delay. Nymphs kept in an upper compartment of two-chamber cages (no visual or tactile contact possible) were similarly effective, but their feces were ineffective, suggesting the mediation of a volatile signal from the nymphs themselves. This was confirmed by examining the effect of volatiles trapped from nymphs and testing synthetic blends of previously identified nymphal aggregation pheromone components (C₆, C₈–C₁₀ aliphatic aldehydes and acids, guaiacol, and phenol) on the sexual maturation of adults. These and previous studies suggest a dual role for nymphal volatiles as nymphal aggregants and adult maturation retardants, similar to the adult volatiles that are known as adult aggregants and maturation accelerants. The results are discussed in terms of the role of the two pheromone systems in synchronizing maturation of the gregarious adults.     

Antibacterial and in vivo reactivity of bioactive glass and poly(vinyl alcohol) composites prepared by melting and sol-gel techniques

Bioactive glass particle is used in the repair of bone defects. This material undergoes a series of surface in vivo reactions, which leads to osteointegration. We evaluated the effect of the bioactive glass synthesis, sol-gel (BG(S)) versus melting (BG(M)), associated with polyvinyl-alcohol (PVA) on in vivo bioactivity with biochemical parameters, liver-kidney histological structure and antibacterial in vitro activity. These composites were testified in many bacteria and implanted in ovariectomized rat. The serum and organs (liver and kidney) of all groups, control and treated rats, were collected to investigate the side effects of our composites, BG(S)-PVA and BG(M)-PVA, in comparison with control and ovariectomized rats. Also, the implants, before and after implantation, were prepared for analysis using physicochemical techniques such as Fourier transform infrared spectroscopy and X-ray diffraction. Our results have shown the stability of natremia, kaliemia, calcemia and phosphoremia. The histological structures of liver and kidney in implanted rats are intact compared to control and ovariectomized rats. BG(S)-PVA is characterized by a higher antibacterial effect on negative and positive gram bacteria than BG(M)-PVA. The physicochemical results have confirmed a progressive degradation of BG(S)-PVA and BG(M)-PVA, while replacing the implant by an apatite layer. But this bioactivity of BG(S)-PVA is faster than BG(M)-PVA. We can therefore confirm, on the one hand, the biocompatibility of our two implants and, on the other hand, the beneficial effect of sol-gel synthesis technique versus melting, both on the antibacterial effect and on the rapid formation of layer hydroxyapatite, and consequently on osteogenesis.     

Characterization of hydrothermally prepared BaTi1−xZrxO3

BaTiO₃ (BTO) and BaTi_0.8Zr_0.2O₃ (BZT) powders were prepared using the hydrothermal method, starting from BaO, TiO₂ and Zr(NO₃)₂, 7H₂O. X-ray diffraction analysis showed that the cubic phase is stable at room-temperature and the pure perovskite phase is obtained after heating the powders for 2 h at 1280 °C. The temperature dependence of the dielectric constant points to ferroelectric behavior. This ferroelectric behavior can likely be due to the presence of a possible quadraticity gradient in the grains since the cubic phase may not be ferroelectric. The diffuse character of the transition is attributed to this quadraticity gradient, to grain size distribution and (for BZT) to spatial fluctuations in the concentrations of the substituted ion (Zr) leading to the coexistence of regions of different Curie temperatures.     

Economic evaluation of fluoride removal by electrodialysis

An economic study was conducted to evaluate the costs of fluoride removal by electrodialysis on the basis of industrial and economic data. The investment and operating costs were estimated for an industrial plant with a capacity of 2200 m³/d water consumption for 50,000 per capita according to Moroccan standards for rural areas. The capital cost was estimated to be € 833,207 and the calculated operating cost to be € 0.154/m³.     

On Hybrid Petri Nets

Petrinets (PNs) are widely used to model discrete event dynamic systems(computer systems, manufacturing systems, communication systems,etc). Continuous Petri nets (in which the markings are real numbersand the transition firings are continuous) were defined morerecently; such a PN may model a continuous system or approximatea discrete system. A hybrid Petri net can be obtained if onepart is discrete and another part is continuous. This paper isbasically a survey of the work of the authors' team on hybridPNs (definition, properties, modeling). In addition, it containsnew material such as the definition of extended hybrid PNs andseveral applications, explanations and comments about the timingsin Petri nets, more on the conflict resolution in hybrid PNs,and connection between hybrid PNs and hybrid automata. The paperis illustrated by many examples.     

3D electro‐thermal modelling and experimental validation of lithium polymer‐based batteries for automotive applications

This article presents an electro‐thermal model of a stack of three lithium ion batteries for automotive applications. This tool can help to predict thermal behaviour of battery cells inside a stack. The open source software OpenFOAM provides the possibility to add heat generation because of Joule losses in a CFD model. Heat sources are introduced at the connectors and are calculated as a function of battery discharge current and internal resistance. The internal resistance is described in function of temperature. Simulation results are validated against experimental results with regard to cooling air flow field characteristic and thermal behaviour of the cell surface. The validation shows that the simulation is capable to anticipate air flow field characteristics inside the battery box. It also predicts correctly the thermal behaviour of the battery cells for various discharge rates and different cooling system conditions. The simulation supports the observation that batteries have a higher temperature close to the connectors and that the temperature increase depends highly on discharge rate and cooling system conditions. Copyright © 2016 John Wiley & Sons, Ltd.