Search results for "OPAL"
showing 10 items of 283 documents
Ancient Schwannoma of the hard palate. An uncommon case report and review
2013
Schwannoma or neurilemmoma is an infrequent benign tumor in the oral cavity that originates from the Schwann cells on the neural sheath of the peripheral nerves. Schwannomas are frequently located in the soft tissues of head and neck region, but only a 1 to 12% of them are located in the oral cavity. Some histological variants of schwannoma have been described including the cellular, plexiform, epithelioid, ancient, and melanocytic types. The “ancient schwannoma” is an uncommon variant of this tumor that shows specific histological characteristics, and is rare in the oral cavity with less than 15 cases described on the literature. Most of them were located in the tongue or in the floor of t…
Anthropomorphism and social presence in Human–Virtual service assistant interactions: The role of dialog length and attitudes
2022
In this study, we delve into the perceived quality of recommendations provided by AI-based virtual service assistants (VSAs). Specifically, the role of the social presence of VSAs in influencing recommendation perceptions is investigated. We also explore how the social presence of a VSA is formed and how perceived anthropomorphism plays a vital role in shaping social presence and eventually instilling trust in VSAs among consumers. These relationships are examined in the context of online government services. The results indicate that consumer interaction with VSAs - manifesting via perceived anthropomorphism, social presence, dialog length, and attitudes - improves recommendation quality p…
Light propagation in triple-film hetero-opals
2005
Spectra of transmitted and forward scattered light of single opal films and triple-film hetero-opals have been compared. The presence of an intermediate film in hetero-opal results in an anomalous increase of the scattered light intensity and in the change of the mainly ballistic light propagation regime to the mainly diffusive one in the frequency range of the photonic bandgap defect state.
Effect of sintering process on color parameters of nano-sized yttria partially stabilized tetragonal monolithic zirconia
2018
Background Sintering process is responsible for aesthetic of zirconia restoration. This study evaluated the effect of different sintering temperatures and sintered-holding times on color parameters of monolithic zirconia. Material and Methods One hundred and thirty five zirconia bar specimens (width-length-thickness = 10×20×1.5 mm) were prepared from yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramic and randomly divided into nine groups to be sintered at different temperatures [decreasing- (SD, 1350°C), regular- (SR, 1450°C), and increasing- (SI, 1550°C) sintering temperature] and different sintered-holding times [shortening- (HS, 60 min), regular- (HR, 120 min), and pro…
Influence of thermal tempering processes on color characteristics of different monolithic computer-assisted design and computer-assisted manufacturin…
2019
Background The optical properties of dental restoration were influenced by the sintering parameters. This study investigated the effects of different tempering processes on optical properties of three monolithic Cad-Cam ceramics. Material and Methods 135 monolithic material bars (4 mm width, 14 mm length, 1.2 mm thickness) were prepared from yttria-stabilized tetragonal zirconia polycrystalline (inCoris TZI, I), zirconia-reinforced lithium silicate (Vita Suprinity, V), and lithium disilicate glass (e.max CAD, E) ceramics, with different tempering processes through slow (S), normal (N), and fast (F) cooling (n=15). The color appearance (∆EW), translucency parameter (TP), contrast ratio (CR),…
A one-pot cascade to protoberberine alkaloids via Stevens rearrangement of nitrile-stabilized ammonium ylides.
2015
A facile one-pot synthesis of protoberberines from readily accessible 1,2,3,4-tetrahydroisoquinoline-1-carbonitriles and 1,2-bis(bromomethyl)arenes is described. The reaction cascade comprises four consecutive transformations, all of which can be effected under a single set of conditions. Ten protoberberines, including the alkaloids pseudopalmatine and pseudoepiberberine, were prepared in yields up to 86% according to this strategy. No chromatographic purification of the products is required, and the route is devoid of any protecting group manipulations.
ChemInform Abstract: A One-Pot Cascade to Protoberberine Alkaloids via Stevens Rearrangement of Nitrile-Stabilized Ammonium Ylides.
2015
This method gives access to quaternary protoberberines including naturally occurring pseudopalmatine (IIIf) and pseudoepiberberine (IIIg).
Mediators of change in online acceptance and commitment therapy for psychological symptoms of parents of children with chronic conditions : An invest…
2020
Highlights: Parents of children with chronic conditions can benefit from an ACT web intervention. Cognitive defusion and acting with awareness mediated effects on psychological symptoms. General psychological flexibility did not mediate effects on outcomes. Improving mindfulness skills aid in optimizing treatment effects in online interventions. peerReviewed
Uvulopalatoplasty by radiosurgery
2003
Preferential CO oxidation over catalysts with well-defined inverse opal structure in microchannels
2008
Catalyst supports of CeO 2 /SiO 2 and Al 2 O 3 with three-dimensionally ordered macroporous structure were fabricated in microchannels by application of PMMA opals as templates. Pt-Rh supported on CeO 2 /SiO 2 showed high efficiency for CO removal in preferential CO oxidation in the presence of excess hydrogen. Pt-Rh supported on Al 2 O 3 with an inverse opal structure showed higher reactivity than that supported on wash-coated Al 2 O 3 layers in microchannel reactor.