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1.
Phys Chem Chem Phys ; 19(33): 22099-22110, 2017 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-28795704

RESUMO

Interactions of anti-inflammatory nimesulide (NM) with different graphene material species were explored employing both ab initio calculations, based on Density Functional Theory (DFT), and a batch adsorption process. The adsorption of NM onto graphene, with and without a vacancy, reduced graphene oxide (rGO) and functionalized graphene nanoribbons was simulated, providing a good understanding of the adsorption process of the NM molecule onto graphene material surfaces. The theoretical results indicate a physisorption interaction between NM and all of the evaluated adsorbents. Based on batch adsorption experiments, it was found that rGO, obtained via a modified Hummers method, is a good nanoadsorbent for the removal of the anti-inflammatory NM from aqueous solutions. The general-order kinetic equation displays the best fit to the experimental data compared with pseudo-first order and pseudo-second order kinetics. The equilibrium data fitted well into the Liu isotherm equation, and the maximum sorption capacity for the adsorption of NM by rGO was 82.4 mg g-1 at 25 °C. Our results of the first principle calculations and the batch adsorption experiments point out that graphene materials are promising nanomaterials for extracting NM from aqueous solutions.


Assuntos
Anti-Inflamatórios não Esteroides/química , Grafite/química , Modelos Teóricos , Sulfonamidas/química , Adsorção , Meia-Vida , Cinética , Nanoestruturas/química , Óxidos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Sulfonamidas/metabolismo , Temperatura , Termogravimetria
2.
Phys Chem Chem Phys ; 18(3): 1526-36, 2016 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-26671178

RESUMO

The interactions of sodium diclofenac drug (s-DCF) with different graphene species were investigated using both first principles calculations based on Density Functional Theory (DFT) and adsorption experiments. Through batch adsorption experiments, it was found that rGO was a good adsorbent for removing the s-DCF drug from aqueous solutions. The general-order kinetic model shows the best fit to the experimental data compared with pseudo-first order and pseudo-second order kinetic adsorption models. The equilibrium data (at 25 °C) were fitted to the Liu isotherm model. The maximum sorption capacity for adsorption of the s-DCF drug was 59.67 mg g(-1) for rGO. The s-DCF adsorption onto pristine graphene, graphene with a vacancy, reduced oxide graphene (rGO) and functionalized graphene nanoribbons were simulated providing a good understanding of the adsorption process of this molecule on graphene-family surfaces. The results predict a physisorption regime in all cases. Based on these results, the ab initio calculations and the adsorption experiments point out that the graphene-family are promising materials for extracting s-DCF from wastewater effluents.


Assuntos
Diclofenaco/química , Grafite/química , Adsorção , Cinética , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica , Termogravimetria
3.
Am J Orthod Dentofacial Orthop ; 114(2): 154-61, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9714280

RESUMO

Literature has shown that, even with the conservative nontraumatic surgical techniques, early repairing surgeries induce changes in the upper dental arch morphologic characteristics in patients with cleft lip and palate. The evaluation of unoperated adult cleft patients enables us to exclude the influence of treatment, emphasizing the morphologic characteristics inherent to the presence of the cleft and its functional counterbalances, that is, the morphologic pattern imposed by cleft. In this study, the maxillary dental casts of 31 unoperated adult complete bilateral cleft lip and palate patients (20 men and 11 women) were compared to a noncleft sample matched for gender. Intercanine, inter-first premolar, inter-second premolar and inter-first molar arch widths measurements as well as arch length were measured from xerox copies taken of the models. The findings indicate the presence of premaxillary prognathism and a progressive increase in the constriction of the dental arches. This constriction of the maxillary segments, even in the absence of surgical intervention, is a result of the absence of an intact palate between the two maxillary processes. Although gender significantly influenced the size of the maxillary arches in the noncleft patients, similar differences were not observed in the cleft group. It seems that the presence of the cleft in itself has the greater influence on the morphologic characteristics of the maxillary arch than gender.


Assuntos
Fenda Labial/patologia , Fissura Palatina/patologia , Arco Dental/patologia , Maxila/patologia , Palato/patologia , Adolescente , Adulto , Estudos de Casos e Controles , Cefalometria , Fenda Labial/complicações , Fissura Palatina/complicações , Arco Dental/anormalidades , Feminino , Humanos , Masculino , Maxila/anormalidades , Pessoa de Meia-Idade , Palato/anormalidades , Prognatismo/etiologia , Valores de Referência , Fatores Sexuais
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