ABSTRACT
In recent years, scientists have been very interested in single crystals of monoaromatic compounds with mechanical softness, but they are hard to find. The present work reports a comparative study of structural, spectroscopic, and quantum chemical investigations of three structurally similar mechanically bending monoaromatic compounds, namely, 2-amino-3-nitro-5-chloro pyridine (I), 2-amino-3-nitro-5-bromo pyridine (II), and 2-amino-3-nitro-5-iodo pyridine (III). The mechanical responses of the three organic crystals studied here are very intriguing due to the similarity of their chemical structures, which only differ in the presence of halogen atoms (Cl, Br, and I) at the fifth position of the pyridine ring and are explained through examining intermolecular interaction energies from energy frameworks analysis, slip layer topology, and Hirshfeld surface analysis. The crystals of all the three feature one dimensional ribbons comprising alternating NaminoHâ¯Onitro and NaminoHâ¯Npyridine hydrogen bonds that form R22(12) and R22(8) dimeric rings, respectively. In (III), weak Iâ¯I interactions link the adjacent ribbons forming a two dimensional sheet. Layer-like structures are observed in all three crystals, with no significant interactions between the adjacent architectures (ribbons or sheets). Energy framework calculations are used for estimating the bending ability of the three compounds, with the three following the order Cl ⪠Br < I. The iterative electrostatic scheme coupled with the supermolecule approach (SM) at the DFT/CAM-B3LYP/aug-cc-pVTZ level is used to calculate the third-order nonlinear susceptibility (χ3) values in a simulated crystalline environment for the static case as well as two typical electric field frequency values, (λ = 1064 nm) and (λ = 532 nm). In addition, estimates of the topological studies (localized orbital locator and electron localization function) and reactivity characteristics (global reactivity parameters, molecular electrostatic potential, and Fukui function) are made for the compounds under investigation. Docking studies done using AutoDock software with a protein target (PDB ID: 6CM4) revealed that three compounds could be used to treat Alzheimer's disease.
ABSTRACT
The coronavirus disease 2019 (COVID-19) pandemic has emerged as a major threat to all healthcare systems across the globe, and it was declared a public health emergency of international concern by the World Health Organization (WHO). The novel coronavirus affects the respiratory system, producing symptoms such as fever, cough, dyspnea, and pneumonia. The association between COVID-19 and coagulation has been previously reported. Due to several inflammatory changes that occur in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections such as alterations in the levels of clotting factors, platelet activation leads to thrombus formation in coronary and cerebral vessels, leading to myocardial infarction and cerebrovascular accidents, respectively.Unfortunately, the progression of hypercoagulability in COVID-19 is rapid in patients with and without comorbidities. Hence, the proper monitoring of thrombotic complications in patients with COVID-19 is essential to avoid further complications. The implementation of guidelines for antithrombotic treatments based on the presentation of the disease is recommended. This review discusses the symptoms and mechanisms of upregulated coagulation in patients with COVID-19.
ABSTRACT
The coronavirus disease 2019 (COVID-19) pandemic has emerged as a major threat to all healthcare systems across the globe, and it was declared a public health emergency of international concern by the World Health Organization (WHO). The novel coronavirus affects the respiratory system, producing symptoms such as fever, cough, dyspnea, and pneumonia. The association between COVID-19 and coagulation has been previously reported. Due to several inflammatory changes that occur in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections such as alterations in the levels of clotting factors, platelet activation leads to thrombus formation in coronary and cerebral vessels, leading to myocardial infarction and cerebrovascular accidents, respectively.Unfortunately, the progression of hypercoagulability in COVID-19 is rapid in patients with and without comorbidities. Hence, the proper monitoring of thrombotic complications in patients with COVID-19 is essential to avoid further complications. The implementation of guidelines for antithrombotic treatments based on the presentation of the disease is recommended. This review discusses the symptoms and mechanisms of upregulated coagulation in patients with COVID-19.
