Transport behavior and negative magnetoresistance in chemically reduced graphene oxide nanofilms.

The electron transport behavior in chemically reduced graphene oxide (rGO) sheets with different thicknesses of 2, 3, and 5 nm was investigated. The four-probe method for the sheet resistance (R(S)) measurement on the intensively reduced graphene oxide samples indicates an Arrhenius characteristic of the electron transport at zero magnetic field B = 0, consistent with previous experimental results on well-reduced GO samples. The anticipated variable range hopping (VRH) transport of electrons in a two-dimensional electron system at low temperatures was not observed. The measured R(S) of the rGO samples are below 52 kΩ/square at room temperature. With the application of a magnetic field up to 4 T, negative magnetoresistance in the Mott VRH regime was observed. The magnetotransport features support a model based on the spin-coupling effect from the vacancy-induced midgap states that facilitate the Mott VRH conduction in the presence of an external magnetic field.

Adjunctive choledochoduodenostomy to choledocholithotomy in the treatment of calculous biliary tract disease.

Between 1986 and 1991, 16 selected patients with calculous biliary tract disease (CBTD) underwent side-to-side choledochoduodenostomy (CDS) as an adjunct to either primary (10 patients) or secondary (six patients) choledocholithotomy. Patients selected for adjunctive CDS were those with common bile duct dilatation > or = 1.5 cm in size. All operations were elective procedures. The stoma of the CDS was about 3.0 cm in size, measured directly. There were no operative deaths. There were no early complications related to the CDS procedure itself, except for two (12.5%) wound infections. CDS significantly eliminates bile stasis which is indicated by a fall in both the serum levels of alkaline phosphatase (from 228 +/- 118 to 72 +/- 22 IU/L, p < 0.01) and total bilirubin (from 4.7 +/- 4.7 to 0.9 +/- 0.2 mg/dL, p < 0.01) postoperatively. Late complications (ascending cholangitis or sump syndrome) of CDS or recurrent symptoms of CBTD were not encountered during the average follow-up period of 21 +/- 18 months. From our clinical results, we suggest that adjunctive CDS to choledocholithotomy is a safe and effective procedure in the treatment of selected patients with CBTD.

Bilateral simultaneous transaxillary sympathectomy in treatment of palmar hyperhidrosis: report of 60 cases.

Bilateral simultaneous transaxillary sympathectomies (BSTS) were established in order to achieve a one-stage transaxillary sympathectomy in the treatment of palmar hyperhidrosis. The features of the BSTS were the patient's supine operative position, parapectoral incision, and bilateral simultaneous procedures. BSTS were safely performed on 60 patients during a 5-year period. No serious complications or recurrences were encountered. The clinical results suggest that BSTS is the technique of choice for one-stage transaxillary sympathectomy in the treatment of palmar hyperhidrosis.