In this research, we reported an interpolated potential energy surface (PES) from ab initio electronic energy of molecular fragments for NH + OH reaction and isotopic substitution. Classical trajectory simulations were performed on this surface to determine reaction probabilities and reaction cross sections in various channels. Also, reaction probability and reaction cross section as a function of the translation energy of fragments were shown. For inelastic collision, the conversion of kinetic energy of particles into internal energy or kinetic energy of another particle was studied. The effect of the impact parameter and relative translational energy of particles on the deflection angle was also investigated. Nonlinear least squares fitting was applied to compute rate constants expressions and these were computed as a function of the cross section. Deuterium was used instead of the hydrogen atom to investigate the effect of the mass of the target molecule and incident molecule on the cross section, reaction probability, scattering angle, and reaction rate.

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In this study, the ability of salvianolic acids A, B, C, F, G and calix[[Formula: see text]]arenes ([Formula: see text], 5, 6 and 8) with different upper rims in the inhibition of insulin amyloid fibril formation was studied using molecular docking. The results were analyzed from a molecular point of view. All of the considering ligands interacted with significant residues of insulin, which had a crucial role in the process of insulin fibrillation. The interactions among the ligands and insulin residues could be done through hydrogen bonding and hydrophobic interactions with good binding affinity. So, these ligands could prevent the formation of the insulin fibril. The good consistency of the docking results of [Formula: see text]-sulfonatocalix[4]arene and [Formula: see text]-sulfonatocalix[6]arene with the experimental results in the previous literature represented the capacity of the current theoretical method to supplement and interpret experimental findings. Also, in this study, salvianolic acids A, C, F and G were suggested as new inhibitors of the insulin amyloid fibril.

The primary challenge of spectroscopic techniques in selective detection and characterization of tautomeric structures of DNA and RNA bases, and moreover, the accurate interpretation and explanation of the experimental results are the main motives of theoretical studies. Surface-enhanced Raman spectroscopy (SERS) can be a powerful approach to distinguish cytosine in the presence of its tautomers. For this respect, herein, the theoretical simulation of the SERS spectra of cytosine and its three most stable tautomers adsorbed on silver clusters is carried out. The calculations of SERS spectra is based on the excitedstate energy gradient approximation as a well-established approach that gives us the knowledge about the properties of excited states and their effect on the pattern of spectra. The good consistency of this theoretical simulation in solution and also the gas phase with the experimental results is achieved and represents the capacity of the current theoretical investigations to interpret and supplement the experimental findings.

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