Chiral gauge theory for graphene.

We construct a chiral gauge theory to describe fractionalization of fermions in graphene. Thereby we extend a recently proposed model, which relies on vortex formation. Our chiral gauge fields provide dynamics for the vortices and also couple to the fermions.

Covariant coordinate transformations on noncommutative space.

We show how to define gauge-covariant coordinate transformations on a noncommuting space. The construction uses the Seiberg-Witten equation and generalizes similar results for commuting coordinates.

Sonographic windsock sign of a duodenal web.

We report a neonate with a duodenal web demonstrating the windsock appearance on US. In neonates, duodenal web is rare and its windsock appearance is also rarely seen. The windsock sign of duodenal web has been a well-known finding on upper gastrointestinal series. The corresponding windsock appearance may be demonstrated on US. Duodenal web can, therefore, be accurately diagnosed by identifying the sonographic windsock sign even in neonates.

Using edge enhancement to identify subtle findings on soft-copy neonatal chest radiographs.

OBJECTIVE: The purpose of this study was to evaluate whether edge enhancement could improve the visibility of subtle findings on soft copies of neonatal chest radiographs. MATERIALS AND METHODS: Two radiologists reviewed 82 soft-copy neonatal chest radiographs before and after the application of edge enhancement on our picture archiving and communication system (PACS). The visibility of a pneumothorax (n = 22), central venous catheter (n = 32), umbilical arterial catheter (n = 36), endotracheal tube (n = 40), and normal anatomic structures (the minor fissure, anterior segmental bronchus of the right upper lobe, and aortic arch, n = 57) was evaluated. Six of 22 soft-copy images depicting a pneumothorax were excluded from the evaluation of image quality either because of the large size of the pneumothorax itself (n = 7) or because of the lack of confirmatory evidence that would have been provided by an additional lateral decubitus (n = 6) or cross-table lateral radiograph (n = 3). Image quality was evaluated by visual grading analysis. RESULTS: The visibility of a pneumothorax (p < 0.01), vascular catheters (p < 0.001), the minor fissure (p < 0.001), and the anterior segmental bronchus of the right upper lobe (p < 0.001) improved significantly after applying edge enhancement to soft copies of neonatal chest radiographs, whereas the visibility of the aortic arch did not improve. Evaluations of the improvements in the visibility of the endotracheal tube were inconsistent. CONCLUSION: Application of edge enhancement to soft copies of neonatal chest radiographs helps radiologists to identify small pneumothoraces, vascular catheters, and delicate normal structures, thereby improving the detection of subtle chest findings in the neonatal intensive care unit.

Fetus-in-fetu in the scrotal sac of a newborn infant: imaging, surgical and pathological findings.

We report a case of fetus-in-fetu located in the scrotal sac of a newborn male infant. Plain radiography (including specimen radiography), ultrasonography and MRI clearly demonstrated vertebral column, ribs, skull, pelvic bones, femurs and a portion of tibiae and humeri. The diagnosis was confirmed by pathological examination.

Holoprosencephaly in a Down syndrome child.

Gross malformation of the central nervous system (CNS) is rare in Down syndrome (DS). To our knowledge we report for the first time the association of trisomy 21 and holoprosencephaly. Because of the low probability of chance concurrence due to unrelated causes, a causal relationship between these two conditions in the patient must be presumed. The anatomic similarity of the holoprosencephalic defect in this infant to that seen in others with autosomal dominant, recessive, sporadic, or syndromal forms of holoprosencephaly, supports the hypothesis that: a) this CNS defect is a causally nonspecific developmental field complex (DFC); b) the increased incidence of such DFC's in the DS represents the result of a nonspecific decrease of developmental homeostasis [Waddington, 1975] due to autosomal aneuploidy.