No abstract

The rupture of a nonparasitic hepatic cyst with biliary communication is rare. We report the case of a patient with a hepatic cyst with biliary communication that spontaneously ruptured and was successfully treated by laparoscopic deroofing and closure of the communication. A 61-year-old woman presented at our hospital with a chief complaint of right upper abdominal pain. Enhanced abdominal CT showed a collapsed hepatic cyst and fluid collection. Drip infusion CT cholangiography showed contrast medium pooling in the collapsed cyst. Therefore, hepatic cyst rupture with biliary communication was diagnosed, and laparoscopic deroofing and closure of the communication were performed. The postoperative course was uneventful, and the patient was discharged on postoperative day 6. In cases of hepatic cyst rupture, even in the presence of biliary communication, laparoscopic deroofing and closure of the communication should be recommended as the first-choice treatment.

The vapor-phase photobromination of 1-bromobutane with molecular bromine (5:1) yields 11 products resulting from direct substitution or the elimination of a bromine atom from the 1 -(bromomethyl)propyl radical. The 1 -butene resulting from elimination undergoes addition, and allylic substitution and addition to yield polyhalogenated materials. The major portion of the bromine (65% ) produced 1,2,3-tribromobutane and 1,2,3,4-tetrabromobutane. Bromination with bromine-81 produced isotopically enriched products which were consistent with the proposed mechanism and showed that 33% of the 1,2-dibromobutane formed arose from the elimination-readdition process. Vapor phase photobromination carried out to partial completion with high concentrations of bromine and hydrogen bromide resulted in only minimal amounts of 0 scission of the 1 -(bromomethyl)propyl radicals. Under these conditions the bromination of perdeuterio-1-bromobutane allowed the determination of the relative rates of transfer, with bromine and hydrogen bromide, of the radicals formed in the reaction and further allowed the determination of the relative rates of abstraction at each position in the molecule. The relative rates of transfer and abstraction indicate that the radical formed 0 to the electronegative bromine atom is stabilized (i.e., more easily formed and less reactive with hydrogen bromide) compared to those in the other positions in the molecule.

In this study, we fabricated quantum point contacts narrower than 100 nm by using an electrostatic potential to open the finite bandgap by applying a perpendicular electric field to bilayer graphene encapsulated between hexagonal boron nitride sheets. The conductance across the quantum point contact was quantized at a high perpendicular-displacement field as high as 1 V/nm at low temperature, and the quantization unit was 2e2/h instead of mixed spin and valley degeneracy of 4e2/h. This lifted degeneracy state in the quantum point contact indicates the presence of valley polarized state coming from potential profile or effective displacement field in one-dimensional channel.