Assessing the Quality of QM/MM Approaches to Describe Vacuo-to-water Solvatochromic Shifts

The performance of different Quantum Mechanics/Molecular Mechanics embedding models to compute vacuo-to-water solvatochromic shifts are investigated. In particular, both non-polarizable and polarizable approaches are analyzed and computed results as compared to reference experimental data. We show that none of the approaches outperforms the others and that errors strongly depend on the nature of the molecular transition. Thus, we prove that the best choice of embedding model highly depends on the molecular system, and that the use a specific approach as a black-box can lead to significant errors and sometimes totally wrong predictions.Comment: 12 pages, 6 figure

QM/Classical Modeling of Surface Enhanced Raman Scattering Based on Atomistic Electromagnetic Models

We present quantum mechanics (QM)/frequency dependent fluctuating charge (QM/ωFQ) and fluctuating dipoles (QM/ωFQFμ) multiscale approaches to model surface-enhanced Raman scattering spectra of molecular systems adsorbed on plasmonic nanostructures. The methods are based on a QM/classical partitioning of the system, where the plasmonic substrate is treated by means of the atomistic electromagnetic models ωFQ and ωFQFμ, which are able to describe in a unique fashion and at the same level of accuracy the plasmonic properties of noble metal nanostructures and graphene-based materials. Such methods are based on classical physics, i.e. Drude conduction theory, classical electrodynamics, and atomistic polarizability to account for interband transitions, by also including an ad-hoc phenomenological correction to describe quantum tunneling. QM/ωFQ and QM/ωFQFμ are thus applied to selected test cases, for which computed results are compared with available experiments, showing the robustness and reliability of both approaches

Fully Atomistic Modeling of Plasmonic Bimetallic Nanoparticles: Nanoalloys and Core-Shell Systems

The recently developed ωFQFμ model (ACS Photonics, 9, 3,025–3,034) is extended to bimetallic nanoparticles, such as nanoalloys and core-shell systems. The method finds its grounds in basic physical concepts, such as Drude conduction theory, electrostatics, interband transitions, and quantum tunneling. The approach, which is parametrized on ab initio simulations of Ag-Au nanoalloys, is challenged against complex Ag-Au nanostructures (spheres, nanorods, and core-shell nanoparticles). Remarkable agreement with available experimental data is found, thus demonstrating the reliability of the newly developed approach

The Oxidative state of LDL is the major determinant of anti/prooxidant effect of coffee on Cu²⁺ catalysed peroxidation

Antioxidants exert contrasting effect on low density lipoprotein (LDL) oxidation catalysed by metals, acting as pro-oxidants under select in vitro conditions. Through our study on the effect of coffee on LDL oxidation, we identified the parameters governing this phenomenon, contributing to the comprehension of its mechanism and discovering significant implications for correct alimentary recommendations. By measuring conjugated diene formation, we have analysed the quantitative and qualitative effects exerted by an extract of roasted coffee on LDL oxidation triggered by copper sulphate. When the relative effects of different coffee concentrations were plotted against the lag time (LT) of control LDL (C-LDL), the apparently random experimental data arranged in sensible patterns: by increasing the LT the antioxidant activity of coffee decreased progressively to become prooxidant. The critical LT, at which coffee switches from antioxidant to prooxidant, increased by increasing coffee concentration. Also the contrasting results obtained following a delayed addition of coffee to the assay, arranged in a simple pattern when referred to the LT of C-LDL: the prooxidant effect decreased to become antioxidant as the LT of C-LDL increased. The dependence of coffee effect on the LT of C-LDL was influenced by LDL but not by metal catalyst concentration. These novel findings point to the oxidative state of LDL as a major parameter controlling the anti/prooxidant effect of coffee and suggest the LT of C-LDL as a potent analytical tool to express experimental data when studying the action exerted by a compound on LDL oxidation

G/R 241 polymorphism of intercellular adhesion molecule 1 (ICAM-1) is associated with Fuchs uveitis

To investigate potential associations of the ICAM-1 gene polymorphisms and Fuchs uveitis in a cohort of Italian patients

A Rare Case of Hodgkin Lymphoma of the Maxillary Sinus.

Hodgkin lymphoma (HL) is an uncommon B-cell malignant disease. It usually presents with mediastinal and/or laterocervical lymph node localization, while primary extranodal HL is a rare entity giving rise to diagnostic and therapeutic challenges. It rarely presents as just extranodal localization, so its presence within the maxillary sinus without any lymphadenopathy is exceptional. Given the rarity of this localization, there is no standard treatment for maxillary sinus HL. We present a case of a patient with extranodal HL of the right maxillary sinus treated with primary surgery followed by adjuvant sequential chemoradiation therapy

The Oxidative State of LDL is the Major Determinant of Anti/Prooxidant Effect of Coffee on Cu2+ Catalysed Peroxidation

Antioxidants exert contrasting effect on low density lipoprotein (LDL) oxidation catalysed by metals, acting as pro-oxidants under select in vitro conditions. Through our study on the effect of coffee on LDL oxidation, we identified the parameters governing this phenomenon, contributing to the comprehension of its mechanism and discovering significant implications for correct alimentary recommendations. By measuring conjugated diene formation, we have analysed the quantitative and qualitative effects exerted by an extract of roasted coffee on LDL oxidation triggered by copper sulphate. When the relative effects of different coffee concentrations were plotted against the lag time (LT) of control LDL (C-LDL), the apparently random experimental data arranged in sensible patterns: by increasing the LT the antioxidant activity of coffee decreased progressively to become prooxidant. The critical LT, at which coffee switches from antioxidant to prooxidant, increased by increasing coffee concentration. Also the contrasting results obtained following a delayed addition of coffee to the assay, arranged in a simple pattern when referred to the LT of C-LDL: the prooxidant effect decreased to become antioxidant as the LT of C-LDL increased. The dependence of coffee effect on the LT of C-LDL was influenced by LDL but not by metal catalyst concentration. These novel findings point to the oxidative state of LDL as a major parameter controlling the anti/prooxidant effect of coffee and suggest the LT of C-LDL as a potent analytical tool to express experimental data when studying the action exerted by a compound on LDL oxidation