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1.
Curr Top Med Chem ; 21(9): 839, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34086546

RESUMO

Due to an oversight of the publisher, Page no 2310 was missing in the published paper and page no 2311 repeated twice in the article entitled "Computational Modeling of Environmental Co-exposure on Oil-Derived Hydrocarbon Overload by Using Substrate-Specific Transport Protein (TodX) with Graphene Nanostructures, 2020, 20(25), 2308-2325 [1]. The page no 2310 is added in the article and the repetition of page no 2311 is corrected. The original article can be found online at https://doi.org/10.2174/1568026620666200820145412.


Assuntos
Simulação por Computador , Exposição Ambiental , Grafite/química , Hidrocarbonetos/química , Transporte Biológico
2.
Curr Top Med Chem ; 20(25): 2308-2325, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32819247

RESUMO

BACKGROUND: Bioremediation is a biotechnology field that uses living organisms to remove contaminants from soil and water; therefore, they could be used to treat oil spills from the environment. METHODS: Herein, we present a new mechanistic approach combining Molecular Docking Simulation and Density Functional Theory to modeling the bioremediation-based nanointeractions of a heterogeneous mixture of oil-derived hydrocarbons by using pristine and oxidized graphene nanostructures and the substrate-specific transport protein (TodX) from Pseudomonas putida. RESULTS: The theoretical evidences pointing that the binding interactions are mainly based on noncovalent bonds characteristic of physical adsorption mechanism mimicking the "Trojan-horse effect". CONCLUSION: These results open new horizons to improve bioremediation strategies in over-saturation conditions against oil-spills and expanding the use of nanotechnologies in the context of environmental modeling health and safety.


Assuntos
Proteínas de Bactérias/química , Teoria da Densidade Funcional , Exposição Ambiental/análise , Grafite/química , Hidrocarbonetos/isolamento & purificação , Proteínas de Membrana/química , Simulação de Acoplamento Molecular , Nanoestruturas/química , Adsorção , Hidrocarbonetos/química , Óleos/química
3.
Phys Chem Chem Phys ; 14(48): 16737-44, 2012 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-23138524

RESUMO

In this paper, the structural, electronic and magnetic properties of carbon nanotubes doped with Al, Fe, Mn and Ti atoms interacting with vitamin C molecules are studied through first principles simulations based on the density functional theory. The charge transfers are obtained from the vitamins into the tubes for adsorption and substitutional doping cases. The highest binding energies of vitamin C molecules are calculated for the Al substitutional and Ti adsorbed cases, with values of about 1.20 and 3.26 eV, respectively. The results demonstrated that, depending on doping, the spin polarizations and the conductance characters of the systems can change, which could be relevant to improve the molecule adsorption on carbon nanostructures.


Assuntos
Alumínio/metabolismo , Ácido Ascórbico/metabolismo , Ferro/metabolismo , Manganês/metabolismo , Nanotubos de Carbono/química , Titânio/metabolismo , Alumínio/química , Ferro/química , Manganês/química , Modelos Moleculares , Nanotubos de Carbono/ultraestrutura , Titânio/química
4.
J Biomed Nanotechnol ; 8(2): 345-9, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22515087

RESUMO

The energetic and structural properties of fullerenes, carbon nanotubes and graphene interacting with vitamins A, B3 and C were studied by first principles simulations. These vitamins, which have antioxidant activities, give support to the cellular metabolism, have biochemical, therapeutic and cosmetic functions, and when combined with carbon nanostructures may have their chemical instability controlled. In this work, the results illustrate that the strongest interaction is between vitamin A and graphene. The binding energies found for the interactions between carbon nanostructures and these vitamins range from 0.10 to 0.93 eV. For all the configurations studied, a physisorption regime is observed without significant changes in the chemical and physical properties of the adsorbed vitamins, which is relevant for a drug delivery system.


Assuntos
Ácido Ascórbico/química , Grafite/química , Nanotubos de Carbono/química , Niacinamida/química , Vitamina A/química , Fulerenos/química , Simulação de Dinâmica Molecular , Nanotubos de Carbono/ultraestrutura , Termodinâmica
5.
Nano Lett ; 5(1): 197-200, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15792439

RESUMO

The electronic and structural properties of a single-walled carbon nanotube (SWNT) under mechanical deformation are studied using first-principles calculations based on the density functional theory. A force is applied over one particular C-atom with enough strength to break the chemical bonds between the atom and its nearest neighbors, leading to a final configuration represented by one tube with a vacancy and an isolated C-atom inside the tube. Our investigation demonstrates that there is a tendency that the first bond to break is the one most parallel possible to the tube axis and, after, the remaining two other bonds are broken. The analysis of the electronic charge densities, just before and after the bonds breaking, helps to elucidate how the vacancy is formed on an atom-by-atom basis. In particular, for tubes with a diameter around 11 angstroms, it is shown that the chemical bonds start to break only when the externally applied force is of the order of 14 nN and it is independent of the chirality. The formation energies for the vacancies created using this process are almost independent of the chirality, otherwise the bonds broken and the reconstruction are dependent.

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