INTRODUCTION Aspiration or ingestion of foreign bodies may occur during dental procedures. Diagnosis and management of these accidents is sometimes challenging. The authors present a small series of clinical cases. CASE 1 Adolescent observed due to suspected accidental bracket ingestion, not visible on x-ray, removed by upper digestive endoscopy. CASE 2 Adolescent observed after accidental ...

A new method to rapidly generate pyrrolidines via a SOMO-activated enantioselective (3 + 2) coupling of aldehydes and conjugated olefins has been accomplished. A radical-polar crossover mechanism is proposed wherein olefin addition to a transient enamine radical cation and oxidation of the resulting radical furnish a cationic intermediate which is vulnerable to nucleophilic addition of a tether...

At the nexus of changing marital and fertility behavior is a new reality of contemporary family life—the fact that a significant fraction of adults today (will) have biological children by more than one partner, sometimes called ‘multi-partnered fertility.’ In this paper, we use data from the Fragile Families and Child Wellbeing Study to explore the consequences of multipartnered fertility for ...

For suitable illumination and observation conditions, sparkles may be observed in metallic coatings. The visibility of these sparkles depends critically on their intensity, and on the paint medium surrounding the metallic flakes. Based on previous perception studies from other disciplines, we derive equations for the threshold for sparkles to be visible. The resulting equations show how the vis...

Background. Much of the sedimentary transport and depositional history of Mars may be recorded in the morphologic characteristics of the individual rocks or particles that make up its sedimentary clast population (defined as a rock fragment or grain resulting from the breakdown of larger rocks or bedrock). Measuring morphology is crucial; it retains the best record of sorting and abrasive effec...

We give an example of a geometry in which the electrostatic force between a point charge and a neutral metallic object is repulsive. The example consists of a point charge centered above a thin metallic hemisphere, positioned concave up. We show that this geometry has a repulsive regime using both a simple analytical argument and an exact calculation for an analogous two-dimensional geometry. A...

Most of the basic research on the electrical behavior of CNTs has been carried out on individual or bundle nanotubes. More recently random or oriented CNT networks (CNTN) are emerging as new material for electronic application. We present the fabrication of thick and dense CNTNs, in the form of freestanding films, and the study of their electric resistance as a function of the temperature, from...

occupational exposure to elemental mercury vapor usually occurs through inhalation during its utilizations. this leads to a variety of adverse health effects. in some islamic cities, this type of poisoning may occur during gilding of shrines using elemental mercury with gold. herein, we report on three male patients aged 20–53 years, who were diagnosed with occupational metallic mercury poisoni...

In face recognition literature, major approaches based on holistic templates and geometrical local features have been taken. Both approaches have certain advantages and disadvantages. In this paper, we explore a new method which integrates the above two approaches. Among many speciic systems, we select LDA (Linear Discriminant Analysis) and MPF (Matching Pursuit Filter) as the representative fr...

The discovery of high-Tc superconductivity in iron arsenides in 2008 has arguably been the biggest breakthrough in this field since the appearance of the copper oxide superconductors in 1986. In iron arsenides, superconductivity up to 55 K originates in layers of edge-sharing [FeAs4/4]-tetrahedra. Meanwhile, a series of different structure types have been identified, but the family of supercon...