Vibrational Characterization and Molecular Electronic Investigations of 2-acetyl-5-methylfuran using FT-IR,FT-Raman,UV–VIS,NMR, and DFT Methods

Spectroscopic (FT-IR, FT-Raman, UV–vis, and NMR) techniques have been extensively used for structural elucidation of compounds along with the study of geometrical and vibrational properties. Herein, 2-acetyl-5-methylfuran, a derivative of furan, was experimentally characterized and analyzed in details using FT-IR, FT-Raman, UV–vis, and ¹H NMR spectroscopic techniques conducted in different solvents. The experimentally analyzed spectral results were carefully compared with theoretical values obtained using density functional theory (DFT) calculations at the B3LYP/6–311?+?+?G (d, p) method to support, validate, and provide more insights on the structural characterizations of the titled compound. The correlated experimental and theoretical structural vibrational assignments along with their potential energy distributions (PEDs) and all the spectroscopic spectral investigations of the titled structure were observed to be in good agreements with calculated results.

     

Prognostic Value of Immunohistochemical Markers for Locally Advanced Rectal Cancer

The aim of this study is to reveal the potential roles of apoptosis markers (Bcl2 and p53), proliferation markers (Ki-67 and CyclD1), and the neuroendocrine marker Chromogranin A as markers for the radioresistance of rectal cancer. Statistically significant differences were found in the expression of p53, Ki-67, and Chromogranin A in groups of patients with and without a favorable prognosis after radiotherapy. The survival analysis revealed that the marker of neuroendocrine differentiation, Chromogranin A, also demonstrated a high prognostic significance, indicating a poor prognosis. Markers of proliferation and apoptosis had no prognostic value for patients who received preoperative radiotherapy. Higher Chromogranin A values were predictors of poor prognosis. The results obtained from studying the Chromogranin A expression suggest that the secretion of biologically active substances by neuroendocrine cells causes an increase in tumor aggressiveness.     

Towards Understanding the Anticorrosive Mechanism of Novel Surfactant Based on Mentha pulegium Oil as Eco-friendly Bio-source of Mild Steel in Acid Medium:a Combined DFT and Molecular Dynamics Investigation

Today,due to the increasingly stringent European directives concerning the use of molecules with certain toxicities towards the environment or their users,the essential oils,extracts,and molecules derived from plants exhibiting the characteristic of being biodegradable can be considered as a source of green corrosion inhibitors instead of harmful synthetic chemicals.The present work was devoted to testing the essential oil extracted from Mentha pulegium leaves(M1) as a corrosion inhibitor for C-steel in 1mol/L HCl solution using both electrochemical techniques and gravimetric measurements for the evaluation of the inhibition efficiencies at different temperatures.The results obtained showed that the inhibition efficiency increased with an increase in Ml concentration to reach a maximum value of 92.21%.We sought to determine the molecule responsible for this high efficiency,starting with the analysis of oil chemical composition by gas chromatography coupled with mass spectrometry.This analysis revealed that menthol(M2)and isomenthol(M3)were the principal constituents.In order to identify the molecule responsible for the inhibition and explain the protection mechanism involved,quantum chemical calculations and Monte Carlo simulations were used to explain the interaction of menthol,the major constituent of M1 with the Fe-surface.To practically confirm these results,we studied the action of 1mol/L HCl on steel with and without the addition of M2 by both methods(gravimetric and electrochemical study).A very high efficiency was obtained,an efficiency of 94.90% at 10^-3 mol/L,which was retained for a long exposure time,and slightly decreased in function of temperature.Finally,a good correlation between the experimental data,theoretical calculations,and SEM studies was obtained,which denied that the Ml efficiency was only a result of a synergy effect and confirmed the high efficiency of Mentha oil and its main component(menthol)as a strong ecological inhibitor of corrosion.