fabricated and prefabricated. In the late 19th century, the “Richmond crown,” a single-piece post-retained crown with a porcelain facing, was engineered to function as a bridge retainer. Richmond crown is not post and core system but it is customized, cast able post and crown system as both are single unit and casted together. It is easier to make cast metal restorations with the aid of posts f...

The synergistic effect of 18-crown-6 derivatives, such as 18-crown-6 (18C6), cis-dicyclohexano-18-crown-6 (DC18C6) and dibenzo-18-crown-6 (DB18C6), on the extraction of trivalent lanthanoids (Ln(3+)) into an ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, with 2-thenoyltrifluoroacetone (Htta) was investigated. The extractability of lighter Ln(3+) was enhanced by ad...

Currently some complex grid applications developing often need orchestrate multiple diverse grid services into a workflow of tasks that can submit for executing on the grid environment. In this paper, we present CROWN FlowEngine—a GPEL-based grid workflow engine for executing grid workflow instances. Besides basic functions of a conventional BPEL4WSbased workflow engine, CROWN FlowEngine has ma...

The asymmetric unit of the title compound, [Rb2(P2S6)(C12H24O6)2]·2CH3CN, contains one half of an [Rb(18-crown-6)2]2[P2S6] unit and one aceto-nitrile solvent mol-ecule. The [Rb(18-crown-6)]2[P2S6] unit is completed by inversion symmetry. Its Rb(+) ion is situated near the centre of the macrocyclic cavity, but is displaced by 0.8972 (1) Å from the O atoms of the crown in the direction of the [P2...

Ecological restoration of degraded riparian Tugai forests in north-western China is a key driver to combat desertification in this region. Recent restoration efforts attempt to recover the forest along with its most dominant tree species, Populus euphratica. The present research observed the response of natural vegetation using an object based change detection method on QuickBird (2005) and Wor...

A series of crown ether complexes of potassium quinolin-8-olates were synthesized and characterized. Catalysis of these complexes towards the ring-opening polymerization of rac-lactide was evaluated. The crown ether complexes of potassium quinolin-8-olate and potassium 2-methylquinolin-8-olate exhibited high catalytic activity and good molecular weight control. The 18-crown-6 complex of potassi...

PURPOSE High crown-implant ratios might affect the biologic and technical performance of a reconstruction. The aim of this study was to assess whether a higher crown-implant ratio of single restorations on 6-mm implants resulted in more peri-implant bone loss and more prosthetic complications during a 1-year followup period. MATERIALS AND METHODS A group of 37 patients were provided with 47 s...

 Abstract Introduction: Considering the importance of anterior teeth in chewing, speaking and esthetics, as well as the high prevalence of crown fracture among various traumatic injuries to the teeth, this study aimed to evaluate the etiology and risk factors associated with crown fractures of anterior teeth in 7-12 years old children. Materials and Methods:This descriptive cross-sectional ...

Two possible causes of crown dilaceration are trauma and developmental disturbances, and it has also been proposed that it might be associated with some developmental syndromes. This article details the diagnosis and describes the alterations in endodontic treatment procedures while managing crown dilaceration in maxillary central incisor. Diagnosis, endodontic access cavity preparation, root c...