Search results for " Simulation"
showing 10 items of 4034 documents
Design and Synthesis of Novel 1,3-Thiazole and 2-Hydrazinyl-1,3-Thiazole Derivatives as Anti-
2019
In the context of there being a limited number of clinically approved drugs for the treatment of Candida sp.-based infections, along with the rapid development of resistance to the existing antifungals, two novel series of 4-phenyl-1,3-thiazole and 2-hydrazinyl-4-phenyl-1,3-thiazole derivatives were synthesized and tested in vitro for their anti-Candida potential. Two compounds (7a and 7e) showed promising inhibitory activity against the pathogenic C. albicans strain, exhibiting substantially lower MIC values (7.81 μg/mL and 3.9 μg/mL, respectively) as compared with the reference drug fluconazole (15.62 μg/mL). Their anti-Candida activity is also supported by molecular docking studies, usin…
Molecular Dynamic Simulation on Polyamide6/Graphene nano-layers nanocomposites
2016
In this work results obtained from Molecular Dynamic Simulation (MDS) on Polyamide 6 (PA6) chains in graphene containing nanocomposites are presented. Through detailed MDS, the interface of complex nanocomposites systems can be fully characterized, furthermore different physical properties, such as density, end-to-end distance , and average radius of gyration of polymers chains can be predicted. This issue is useful for the design of highly value-added nanocomposites and the optimization of their production process, by defining transformation steps and status variables (temperature, time and pressure), that can also help the industrial production.
Inhibition of Eimeria tenella CDK-related kinase 2: From target identification to lead compounds.
2010
Apicomplexan parasites encompass several human- and animal-pathogenic protozoans such as Plasmodium falciparum, Toxoplasma gondii, and Eimeria tenella. E. tenella causes coccidiosis, a disease that afflicts chickens, leading to tremendous economic losses to the global poultry industry. The considerable increase in drug resistance makes it necessary to develop new therapeutic strategies against this parasite. Cyclin-dependent kinases (CDKs) are key molecules in cell-cycle regulation and are therefore prominent target proteins in parasitic diseases. Bioinformatics analysis revealed four potential CDK-like proteins, of which one—E. tenella CDK-related kinase 2 (EtCRK2)—has already been charact…
Diatropicity of tetraazanaphthalenes
2006
Tetraazanaphthalenes are diatropic molecules, whose magnetic response to a magnetic field perpendicular to the molecular plane closely resembles that of naphthalene. The out-of-plane component of the magnetic susceptibility tensor and its strong anisotropy can be used as quantifiers of magnetic aromaticity. Maps showing streamlines and modulus of the current density field provide clear evidence for diatropicity of these systems. They also explain the strong anisotropy of carbon and nitrogen magnetic shielding, which is determined by the big out-of-plane component of the nuclear shielding tensor. The electronic ring currents observed in the map deshield the nuclei of ring hydrogens by enforc…
Computational design of biological catalysts
2008
The purpose of this tutorial review is to illustrate the way to design new and powerful catalysts. The first possibility to get a biological catalyst for a given chemical process is to use existing enzymes that catalyze related reactions. The second possibility is the use of immune systems that recognize stable molecules resembling the transition structure of the target reaction. We finally show how computational techniques are able to provide an enormous quantity of information, providing clues to guide the development of new biological catalysts
Experimental and DFT Studies on Competitive Heterocyclic Rearrangements. 3. A Cascade Isoxazole−1,2,4-Oxadiazole−Oxazole Rearrangement
2008
The thermal rearrangements of 3-acylamino-5-methylisoxazoles 1 have been investigated under basic and neutral conditions and interpreted with the support of computational data. The density functional theory (DFT) study on the competitive routes available for the base-catalyzed thermal rearrangement of isoxazoles 1 showed that the Boulton-Katritzky (BK) rearrangement, producing the less stable 3-acetonyl-1,2,4-oxadiazoles 5, is a much more favored process than either the migration-nucleophilic attack-cyclization (MNAC) or the ring contraction-ring expansion (RCRE). In turn, an increase in reaction temperature will promote the MNAC of oxadiazoles 5, producing the more stable 2-acylaminooxazol…
Natural micro-scale heterogeneity induced solute and nanoparticle retardation in fractured crystalline rock.
2011
Abstract We studied tracer (Tritiated Water (HTO); Tritium replaces one of the stable hydrogen atoms in the H 2 O molecule) and nanoparticle (quantum dots (QD)) transport by means of column migration experiments and comparison to 3D CFD modeling. Concerning the modeling approach, a natural single fracture was scanned using micro computed tomography (μCT) serving as direct input for the model generation. The 3D simulation does not incorporate any chemical processes besides the molecular diffusion coefficient solely reflecting the impact of fracture heterogeneity on mass (solute and nanoparticles) transport. Complex fluid velocity distributions (flow channeling and flowpath heterogeneity) evo…
Predicting Skin Permeability by Means of Computational Approaches: Reliability and Caveats in Pharmaceutical Studies
2019
The skin is the main barrier between the internal body environment and the external one. The characteristics of this barrier and its properties are able to modify and affect drug delivery and chemical toxicity parameters. Therefore, it is not surprising that permeability of many different compounds has been measured through several in vitro and in vivo techniques. Moreover, many different in silico approaches have been used to identify the correlation between the structure of the permeants and their permeability, to reproduce the skin behavior, and to predict the ability of specific chemicals to permeate this barrier. A significant number of issues, like interlaboratory variability, experim…
Micelles, Rods, Liposomes, and Other Supramolecular Surfactant Aggregates: Computational Approaches
2017
Surfactants are an interesting class of compounds characterized by the segregation of polar and apolar domains in the same molecule. This peculiarity makes possible a whole series of microscopic and macroscopic effects. Among their features, their ability to segregate particles (fluids or entire domains) and to reduce the surface/interfacial tension is the utmost important. The interest in the chemistry of surfactants never weakened; instead, waves of increasing interest have occurred every time a new field of application of these molecules has been discovered. All these special characteristics depend largely on the ability of surfactants to self-assemble and constitute supramolecular struc…
Rational design of allosteric modulators of the aromatase enzyme: An unprecedented therapeutic strategy to fight breast cancer.
2019
Estrogens play a key role in cellular proliferation of estrogen-receptor-positive (ER+) breast cancers (BCs). Suppression of estrogen production by competitive inhibitors of the enzyme aromatase (AIs) is currently one of the most effective therapies against ER + BC. Yet, the development of acquired resistance, after prolonged treatments with AIs, represents a clinical major concern. Serendipitous findings indicate that aromatase may be non-competitively inhibited by clinically employed drugs and/or industrial chemicals. Here, by performing in silico screening on two putative allosteric sites, molecular dynamics and free energy simulations, supported by enzymatic and cell-based assays, we id…