Search results for " bonding"
showing 10 items of 934 documents
Efficient, non-toxic anion transport by synthetic carriers in cells and epithelia.
2016
Transmembrane anion transporters (anionophores) have potential for new modes of biological activity, including therapeutic applications. In particular they might replace the activity of defective anion channels in conditions such as cystic fibrosis. However, data on the biological effects of anionophores are scarce, and it remains uncertain whether such molecules are fundamentally toxic. Here, we report a biological study of an extensive series of powerful anion carriers. Fifteen anionophores were assayed in single cells by monitoring anion transport in real time through fluorescence emission from halide-sensitive yellow fluorescent protein. A bis-(p-nitrophenyl)ureidodecalin shows especial…
Effect of thermocycling with or without 1 year of water storage on retentive strengths of luting cements for zirconia crowns
2015
Abstract Statement of problem Bond stability between zirconia crowns and luting cement and between cement and dentin is a main concern; however, only limited evidence is available as to its longevity. Purpose The purpose of this in vitro study was to measure the retentive strengths of 7 self-adhesive cements (RelyX Unicem Aplicap, RelyX Unicem Clicker, RelyX Unicem 2 Automix, iCEM, Maxcem Elite, Bifix SE, SpeedCem), 2 adhesive cements with self-etch primers (Panavia 21, SEcure), 1 glass ionomer cement (Ketac Cem), 1 resin-modified glass ionomer cement (Meron Plus), and 1 zinc phosphate cement for luting zirconia crowns (LAVA) to extracted teeth after thermocycling with or without 1 year of …
Vertical root fracture in endodontically treated teeth: A review of 25 cases
2001
Abstract Objective: We sought to examine the clinical conditions under which 25 endodontically treated teeth underwent vertical root fracture (VRF) and to relate this condition to the time elapsed from endodontic treatment to fracture. Study Design: This was a retrospective study in which we reviewed 25 case histories of patients with postendodontic VRF and studied the effect of various pretreatment and posttreatment factors as they related to VRF. Results And Conclusions: The mean time to VRF was 54 months; this was not significantly influenced by the presence or absence of prior restoration or by the presence or absence of a crown fitting. The use of a prefabricated, cylindrical, cemented…
Acid−Base Properties of Synthetic and Natural Polyelectrolytes: Experimental Results and Models for the Dependence on Different Aqueous Media
2008
Protonation constants of several natural and synthetic humates and fulvates were determined by ISE-H+ potentiometry in different ionic media (alkali metal halides and tetraethylammonium iodide) at different ionic strengths and T ) 298.15 K. Experimental data obtained in previous studies of different synthetic (polyacrylates, polymethacrylates, polyacrylate-co-maleate) and naturally occurring (alginate, humic substances) polycarboxylates were also taken into account in the general analysis of acid-base properties of polyelectrolytes. Protonation constants were expressed as a function of the dissociation degree (R) using three models, namely, a simple linear model, the Ho¨gfeldt three-paramet…
Speciation Studies of Bifunctional 3-Hydroxy-4-Pyridinone Ligands in the Presence of Zn2+ at Different Ionic Strengths and Temperatures
2019
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“Fear No More”: Gender Politics and the “Hell” of New Media Technologies in Michael Almereyda’s Cymbeline (2014)
2018
The paper focuses on Michael Almereyda’s Cymbeline (2014), a modernized re-telling of Shakespeare’s play in which the Briton motorcycle gang, led by drug kingpin Cymbeline, comes into conflict with the Rome police force, led by Caius Lucius. In the film, which has been defined as “Shakespeare in the Instagram age,” sustained attention to media practices and technologies competes with the incorporation of textual material. In particular, the film displays a conflict between old media, including Shakespearean textual inscriptions (e.g. the “Fear No More” woodcut that Posthumus makes and sends to Imogen as a gift), and new media technologies, pervasively associated with perverse visualization …
Determining the effects of Eugenol on the bond strength of resin-based restorative materials to dentin : a meta-analysis of the literature
2020
Este artículo se encuentra disponible en la siguiente URL: https://www.mdpi.com/2076-3417/10/3/1070/htm Este artículo pertenece al número especial " Permanent and long-term biodegradable biomaterials". The aim of this study was to determine whether the residual presence of eugenol in coronal dentin may compromise the bond strength of resin-based restorative materials. A search was performed on MEDLINE/Pubmed, Scopus, and by hand search for relevant papers. No restriction was applied for language and publication date. The studies selected for analysis tested specimens with reduced size (micro-shear bond strength ( SBS) and micro-tensile bond strength ( TBS)) of adhesive systems and resin-bas…
Ethylammonium hydrogen oxalate–oxalic acid (2/1)
2019
The reaction between ethylamine and oxalic acid in water in a 1:1 molar ratio afforded the title salt, C2H8N+·C2HO4 −·0.5C2H2O4. The hydrogen oxalate anions interact through hydrogen bonding and are organized into a chains propagating along the c-axis direction. The chains are connected to the neighbouring cations and oxalic acid molecules by N—H...O and O—H...O hydrogen bonds and N...O dipole–dipole contacts, leading to a supramolecular three-dimensional network.
Solid state conformational behavior and interactions of a series of aromatic oligoamide foldamers
2016
The topic of this thesis is aromatic oligoamide foldamers. The literary review of the thesis discusses the general features of foldamers and their design and then focuses on the specific examples of aromatic oligoamide foldamers. The experimental part of the thesis discusses the design and preparation of a family of aromatic oligoamide foldamers that can adopt a helical conformation. The folding is directed by intramolecular hydrogen bonding and stabilized by intramolecular aromatic interactions. The focus of the thesis is the analysis of the solid state conformations of ten foldamer analogues. The analysis is based on forty different crystal structures which are determined using single cry…
Charge Transfer Transitions in Neutral and Ionic Polypeptides: A Theoretical Study
2001
We report on the vertical electronic excitation spectra of neutral polypeptides and their radical ions. Model systems including tri-, tetra-, and octamers in an α-helix and β-sheet alike conformation are studied by various computational methods. The results allow us to assign the band centered at about 7.5 eV in the absoption spectra of proteins to charge transfer states. The calculations also support conclusions from recent experiments which propose charge transfer as a possible mechanism for photoinduced electron transfer in polypeptide cations.