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1.
Case Rep Dent ; 2020: 2769873, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32908715

RESUMO

Summary. Prosthetic rehabilitation of a completely edentulous patient is no more confined to replacement of missing teeth. Long span of edentulism and ageing leads to loss of support of the facial musculature, which is of great concern in treating completely edentulous patients. Flaccid facial musculature eventually leads to sunken cheeks and unesthetic appearance, causing a negative impact on psychological well-being of the patient. The use of conventional complete dentures can restore the loss to some extent, but in some cases, additional support is required. The present clinical report exemplifies the use of magnet-retained detachable maxillary cheek plumper prosthesis in a completely edentulous patient with sunken cheeks.

2.
J Colloid Interface Sci ; 469: 38-46, 2016 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-26866888

RESUMO

Keeping in view the role of neurotransmitters (NTs) in central nervous system diseases and in controlling various physiological processes, present study is aimed to study the binding of neurotransmitters (NTs) such as norepinephrine hydrochloride (NE) and serotonin hydrochloride (5-HT) with twin tailed surfactant sodium bis(2-ethylhexyl)sulfosuccinate (AOT). Spectroscopic and electrochemical measurements combined with microcalorimetric measurements were used to characterize the interactions between AOT and NTs. Meteoric modifications to emission profile and absorption spectra of NTs upon addition of AOT are indicative of the binding of NTs with AOT. Distinct interactional states such as formation of ion-pairs, induced and regular micelles with adsorbed NTs molecules have been observed in different concentration regimes of AOT. The formation of ion-pairs from oppositely charged NTs and AOT is confirmed by the reduced absorbance, quenched fluorescence intensity and decrease in peak current (ipa) as well as shifts in peak potential (Epa) values. The stoichiometry and formation of the NTs-AOT complexes has been judged and the extent of interactions is quantitatively discussed in terms of binding constant (K) and free energy of binding (ΔG°). The enthalpy (ΔH°mic) and free energy of micellization (ΔG°mic) for AOT in presence and absence of NTs are determined from the enthalpy curves.


Assuntos
Ácido Dioctil Sulfossuccínico/química , Neurotransmissores/química , Norepinefrina/química , Serotonina/química , Tensoativos/química , Ânions/química , Físico-Química , Micelas , Termodinâmica
3.
Phys Chem Chem Phys ; 16(12): 5667-77, 2014 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-24522552

RESUMO

The interactions of methylene blue (MB), a redox active dye with surface active biamphiphilic ionic liquids (BAILs): 1-butyl-3-methylimidazolium dodecylsulfate, [C4mim][C12OSO3] and 1-hexyl-3-methylimidazolium dodecylsulfate [C6mim][C12OSO3] have been investigated in aqueous medium to explore the candidature of surface active ionic liquids (ILs) in the field of dye-surfactant chemistry. Various thermodynamic, spectroscopic and electrochemical techniques such as conductivity, steady-state fluorescence, UV-visible absorption, and cyclic voltammetry (CV) have been used to obtain comprehensive information about MB-BAIL interactions. The presence of MB is seen to enhance the critical micellar concentration (cmc) of BAILs. The extent of interaction between the MB and BAILs varies with the concentration as well as the nature of BAILs. Different interactional phenomena such as the formation of ion-pair complexes, dimers, and solubilisation of monomers of MB have been observed in different concentration regimes of BAILs. A quantitative evaluation of the process of interaction between MB and BAILs has been made in terms of various micellar and binding parameters exploiting UV-visible absorption and CV measurements. Comparatively more hydrophobic [C6mim][C12OSO3] interacts strongly with MB as compared to [C4mim][C12OSO3] via hydrophobic and electrostatic interactions.

4.
J Colloid Interface Sci ; 394: 346-52, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23375810

RESUMO

With an aim to characterize the micellar aggregates of imidazolium based ionic liquids, a new potentiometric PVC sensor based on neutral ion-pair complexes of dodecylmethylimidazolium bromide-sodium dodecylsulfate (C12MeIm(+)DS(-)) has been developed. The electrode exhibited a linear response for the concentration range of 7.9×10(-5)-9.8×10(-3) M with a super-Nernstian slope of 92.94 mV/decade, a response time of 5 s and critical micellar concentration (cmc) of 10.09 mM for C12MeImBr. The performance of the electrode in investigating the cmc of C12MeImBr in the presence of two drugs [promazine hydrochloride (PMZ) and promethazine hydrochloride (PMT)] and three triblock copolymers (P123, L64 and F68) has been found to be satisfactory on comparison with conductivity measurements. Various micellar parameters have been evaluated for the binary mixtures of C12MeImBr with drugs and triblock copolymers using Clint's, Rubingh's, and Motomura's approach. Thus the electrode offers a simple, straightforward and relatively fast technique for the characterization of micellar aggregates of C12MeImBr, complementing existing conventional techniques. Further, the analytical importance of proposed C12MeIm(+)-ISE as end point indicator in potentiometric titrations and for direct determination of cationic surfactants [cetylpyridinium chloride (CPC), tetradecyltrimethylammonium bromide (TTAB), benzalkonium chloride (BC)] in some commercial products was judged by comparing statistically with classical two-phase titration methods.

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