Copper corrosion prevention in 3.5% NaCl solution by Spartium junceum petals extract as an eco-friendly bio-inhibitor: kinetic and thermodynamic studies.

During the last decades, numerous studies were performed to introduce green corrosion inhibitors. So, various materials were utilized due to their being bio-degradable, available, and inexpensive. Because of the aforementioned aspects, Spartium Junceum petals extract (SJPE) was used as a new bio-inhibitor for the prevention of copper corrosion in a 3.5 wt% NaCl solution. This extract was obtained in water as a non-toxic solvent. Also, gas chromatography-mass spectrometry (GC-MS) confirmed the presence of organic molecules containing O, N, and F heteroatoms in SJPE, which are important for inhibitors. Also, Fourier-transform infrared spectroscopy (FT-IR) was used to identify the functional groups of the inhibitor molecules. Moreover, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques were used which verified the great effect of this procedure to promote resistance corrosion of copper substrate. In addition, scanning electron microscopy (SEM) exhibited the surface morphology of copper substrate in the presence of SJPE which demonstrated the improvement of corrosion resistance in comparison to the absence of this bio-inhibitor. It should be noted that by increasing the amount of SJPE, the inhibition efficiency was ameliorated up to 87.8%. Furthermore, variation in temperature magnitude between 298 and 338 K implied that SPJE can improve inhibition behavior in higher temperatures. By applying temperature effect study data, the value of activation energy in the presence of the inhibitor was calculated (37.9 kJ mol-1), and the adsorption isotherm was Langmuir. Also, these data showed the inhibition mechanism is physical adsorption. The proposed inhibitor can be used as an efficient, eco-friendly, and inexpensive bio-inhibitor for the prevention of copper corrosion.

The corrosion inhibition of carbon steel in 1 M HCl solution by Oestrus ovis larvae extract as a new bio-inhibitor.

Since, nowadays, utilizing the eco-friendly and economic corrosion inhibitors in various industries is a challenge, in this research, the corrosion behavior of carbon steel in the HCl solution by the addition of the extract of Oestrus ovis larvae as a novel bio-inhibitor has been evaluated. The electrochemical tests plus the gravimetric investigations were performed to study the corrosion property of steel substrates in various concentrations of bio-inhibitor (0.25-3 g/L). Different methods such as grazing incidence X-ray diffraction, field emission scanning electron microscopy (FESEM), and atomic force spectroscopy (AFM), were utilized to detect the chemical composition and morphology of corroded surfaces. Results of the Tafel polarization showed that the inhibition efficiency was about 57-86% with the highest value at the inhibitor concentration of 1 g/L. Electrochemical impedance spectroscopy results indicated that with the specified concentration of bio-inhibitor the electrochemical properties of samples changed based on the suggested electrical circuit. Results showed that the adsorption isotherm of the inhibitor was the Langmuir model with the cathodic-anodic performance. Both FESEM and AFM images demonstrated that the intensity of deterioration and the roughness of corroded surfaces reduced significantly at the optimum concentration of inhibitor (1 g/L). The inhibition mechanism was proposed based on experimental results.

UVB represses melanocyte cell migration and acts through ß-catenin.

The exposure of skin to ultraviolet (UV) radiation can have both beneficial and deleterious effects: it can lead, for instance, to increased pigmentation and vitamin D synthesis but also to inflammation and skin cancer. UVB may induce genetic and epigenetic alterations and have reversible effects associated with post-translational and gene regulation modifications. ß-catenin is a main driver in melanocyte development; although infrequently mutated in melanoma, its cellular localization and activity are frequently altered. Here, we evaluate the consequence of UVB on ß-catenin in the melanocyte lineage. We report that in vivo, UVB induces cytoplasmic/nuclear relocalization of ß-catenin in melanocytes of newborn mice and adult human skin. In mouse melanocyte and human melanoma cell lines in vitro, UVB increases ß-catenin stability, accumulation in the nucleus and cotranscriptional activity, leading to the repression of cell motility and velocity. The activation of the ß-catenin signalling pathway and its effect on migration by UVB are increased by an inhibitor of GSK3ß, and decreased by an inhibitor of ß-catenin. In conclusion, UVB represses melanocyte migration and does so by acting through the GSK3-ß-catenin axis.