Large area precision optical coatings by reactive ion beam sputtering.

The demand for ion beam sputtering (IBS) coated substrates is growing. In order to introduce IBS technology into new fields of application, the uniform deposition area (UDA) must be further increased. In the present investigation, a simple approach toward enlarging a UDA and the corresponding scaling laws are presented.

Evaluation of the use of botulinum toxin in children with achalasia.

Background: Achalasia is rare in children. Recently, injection of botulinum toxin into the lower esophageal sphincter has been studied as an alternative to esophageal pneumatic dilatation or surgical myotomy as treatment for achalasia. In the current study, the effects of botulinum toxin were investigated in the largest known series of children with achalasia.

Chewing gum bezoars of the gastrointestinal tract.

Children have chewed gum since the Stone Age. Black lumps of prehistoric tar with human tooth impressions have been found in Northern Europe dating from approximately 7000 BC (Middle Stone Age) to 2000 BC (Bronze Age). The bite impressions suggest that most chewers were between 6 and 15 years of age.

Differential diagnosis of dysphagia in children.

Dysphagia in children often presents a difficult diagnostic challenge. A systematic approach in each individual can help with diagnosis and treatment. An overview of the differential diagnosis and the diagnostic and treatment options available is provided.