This study used a mechanical test to evaluate the flexibility of instruments from the K3 (conicity 0.04) and the ProTaper Universal systems when they were new and after 5 uses in simulated canals. Five sets of instruments of each system were tested: K3 (15, 20, 25, 30, 35, 40 and 45) and ProTaper Universal (S1, S2, F1, F2, F3, F4 and F5). Each set of instruments was used to prepare a simulated ...

We review recent developments in the arithmetic of K3 surfaces. Our focus lies on aspects of modularity, Picard number and rational points. Throughout we emphasise connections to geometry.

In this paper we show that there is a correspondence between some K3 surfaces with non-isometric transcendental lattices constructed as a twist of the transcendental lattice of the Jacobian of a generic genus 2 curve. Moreover, we show the existence of a correspondence between a general K3 surface with ρ = 17 and a Kummer surface having transcendental lattices Q-Hodge isomorphic.

We present a complete list of extremal elliptic K3 surfaces (Theorem 1.1). As an application, we give a sufficient condition for the topological fundamental group of complement to an ADE-configuration of smooth rational curves on a K3 surface to be trivial (Proposition 4.1 and Theorem 4.3).

A symplectic involution on a K3 surface is an involution which preserves the holomorphic 2-form. We prove that such a symplectic involution acts as the identity on the CH0 group of the K3 surface, as predicted by Bloch’s conjecture. 2010 Mathematics Subject Classification: 14C25, 14J28

We show that the geometry of K3 surfaces with singularities of type AD -E contains enough information to reconstruct a copy of the Lie algebra associated to the given Dynkin diagram. We apply this construction to explain the enhancement of symmetry in F and IIA theories compactified on singular K3's.

In this note, we consider K3 surfaces X with an action by the alternating group A 5. We show that if a cyclic extension A 5 .C n acts on X then n = 1, 2, or 4. We also determine the A 5-invariant sublattice of the K3 lattice and its discriminant form.

The Matrix theory description of Type IIA string theory on a compact K3 surface as the theory of Neveu-Schwarz five-branes oñ K3 × S 1 is analyzed. The full multiplet of space-time BPS states is identified in the five-brane world-volume as fluxes. October 1997

In this note, we report some progress we made recently on the automorphisms groups of K3 surfaces. A short and straightforward proof of the impossibility of Z/(60) acting purely non-symplectically on a K3 surface, is also given, by using Lef-schetz fixed point formula for vector bundles.

BACKGROUND The occurrence of myocyte necrosis during reperfusion of ischemic myocardium is controversial. This study measured myocardial 2-deoxyglucose uptake, correlated with histology, to determine whether loss of viability occurred during reperfusion of ischemic myocardium. METHODS AND RESULTS In 12 anesthetized dogs, the left anterior descending coronary artery was occluded for 90 minutes...