Background and Aim: Different methods and materials are available for post and core (P&C) fabrication. We aimed to compare the fracture resistance and failure modes of endodontically treated maxillary central incisors restored with six different P&C systems. Materials and Methods: In this in-vitro study, after endodontic treatment and coronal preparation of 60 maxillary central incisors, six d...

the formation of atoll garnet in the ardara aureole, nw ireland, is discussed using the textural, chemical and electron backscatter diffraction (ebsd) data. textural evidence suggests the possibility of incipient of garnet replacement from the core. in addition, the presence of staurolite and andalusite in the core of small atoll garnets as well as the occurrence of sillimanite in the core of l...

background: different postdesigns and materials are available; however, no consensus exists regarding superiority for stress distribution. the aim of this study was to evaluate the effect of design and material of post with or without ferrule on stress distribution using finite element analysis. materials and methods: a total of 12 three‑dimensional (3d) axisymmetric models of postretained cent...

conclusions there is an as yet unexplained association between hcv and host parameters with unknown mechanisms in patients with chronic hcv infection. the assessments of core aa 70 substitution and polymorphisms near the ifnl3 gene could offer promising steps to improve the management of patients with hcv. background molecular studies have demonstrated that the hepatitis c virus (hcv) genotype ...

As an international legal instrument, the International Health Regulations (IHR) is internationally binding in 196 countries, especially in all the member states of the World Health Organization (WHO). The IHR aims to prevent, protect against, control, and respond to the international spread of disease and aims to cut out unnecessary interruptions to traffic and trade. To meet IHR requirements,...

In this paper we study finding the $(k,l)$-core problem on a tree which the vertices have positive or negative weights. Let $T=(V,E)$ be a tree. The $(k,l)$-core of $T$ is a subtree with at most $k$ leaves and with a diameter of at most $l$ which the sum of the weighted distances from all vertices to this subtree is minimized. We show that, when the sum of the weights of vertices is negative, t...