Publications by authors named "Luis A Zarate-Hernandez"

Context: Several descriptors from conceptual density functional theory (cDFT) and the quantum theory of atoms in molecules (QTAIM) were utilized in Random Forest (RF), LASSO, Ridge, Elastic Net (EN), and Support Vector Machines (SVM) methods to predict the toxicity (LD) of sixty-two organothiophosphate compounds. The A-RF-G1 and A-RF-G2 models were obtained using the RF method, yielding statistically significant parameters with good performance, as indicated by R values for the training set (R) and R values for the test set (R), around 0.90.

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Article Synopsis
  • The text introduces a more efficient algorithm for solving the near-congruence problem in rigid molecules and clusters using iterative assignment and alignment steps with biased costs.
  • This new method enhances efficiency by up to 5 orders of magnitude compared to older, unbiased approaches and is capable of handling large systems with hundreds or thousands of atoms.
  • The algorithm, available as an open-source Fortran library, can be utilized in global optimization techniques to identify local minima or basins in molecular structures.
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Thermal processing of certain foods implies the formation of acrylamide, which has been proven to provoke adverse effects on human health. Thus, several strategies to mitigate it have been developed. One of them could be the application of organosulfur compounds obtained from natural sources to react with the acrylamide, forming non-toxic adducts.

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Compounds containing carbamate moieties and their derivatives can generate serious public health threats and environmental problems due their high potential toxicity. In this study, a quantitative structure-toxicity relationship (QSTR) model has been developed by using one hundred seventy-eight carbamate derivatives whose toxicities in rats (oral administration) have been evaluated. The QSRT model was rigorously validated by using either tested or untested compounds falling within the applicability domain of the model.

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The relationship between structure and corrosion inhibition of a series of twenty-eight quinoline and pyridine derivatives has been established through the investigation of quantum descriptors calculated with PBE/6-311 +  + G** method. A quantitative structure-property relationship (QSPR) model was obtained by examining these descriptors using a genetic algorithm approximation method based on a multiple linear regression analysis. The results indicate that the efficiency of corrosion inhibitors is strongly associated with hardness (η), minimal electrostatic potential (ESP), and volume (V) descriptors.

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Article Synopsis
  • - This study examines how to optimize the shape and total spin of small iron clusters (Fe) using Simulated Annealing (SA) and DFTB theory, focusing on clusters ranging from 3 to 40 atoms.
  • - The researchers allowed for a flexible total spin by adjusting the occupancy of spin densities during the SA process, leading to varied spin states throughout the simulations.
  • - Their results showed that the optimized cluster structures closely matched previously reported geometries and magnetic moments, and they also computed binding energies to further validate their findings, noting few discrepancies likely due to competing magnetic states at high temperatures.
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The structural and electronic properties were calculated for seventy organic compounds used as dye sensitizers in solar cells, applying the B3LYP exchange-correlation energy functional with the 6-311G∗∗ basis set. Moreover, the present study proposes two new quantitative structure-property relationship (QSPR) models that enable the prediction of the power conversion efficiency (PCE) and maximum absorption wavelength (λ) of these systems, the two QSPR models were validated using the coefficient of determination (R) of 0.62 for both models with the leave-one-out cross-validation correlation coefficient (Q) of 0.

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Article Synopsis
  • The study focuses on the synthesis of two oligophenyleneimine pentamers, DAFCHO and FDACHO, which contain terminal aldehydes, using mechanochemistry methods and various diamines.* -
  • The compounds were characterized using spectroscopy techniques (¹H and C-NMR, FT-IR, mass spectrometry) and displayed interesting photochromic properties in chloroform when exposed to sunlight, with notable energy band gap values measured.* -
  • Electrochemical studies revealed their potential as organic semiconductors, with HOMO and LUMO values indicating favorable electronic properties, and findings were further supported by Density Functional Theory (DFT) calculations.*
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