Nonequilibrium transport through a quantum dot weakly coupled to Luttinger liquids

We study the nonequlibrium transport through a quantum dot weakly coupled to Luttinger liquids (LL). A general current expression is derived by using nonequilibrium Green function method. Then a special case of the dot with only a single energy level is discussed. As a function of the dot's energy level, we find that the current as well as differential conductance is strongly renormalized by the interaction in the LL leads. In comparison with the system with Fermi liquid (FL) leads, the current is suppressed, consistent with the suppression of the electron tunneling density of states of the LL; and the outset of the resonant tunneling is shifted to higher bias voltages. Besides, the linear conductance obtained by Furusaki using master equation can be reproduced from our result.Comment: 8 pages, 3 figures, Late

Optimizing Clinical Utility of the Ultrasound-guided Core Biopsy for Head and Neck Tumor

BackgroundThe goal of this study is to validate the clinical utility and define the procedure setting of minimally invasive core biopsy that is performed under ultrasound guidance with small-gauge needles (USCB) in head and neck tumors.Materials and methodsA consecutive 56 patients with head and neck tumors received USCB with informed consents. Patients received USCB with different gauges of core needles randomly. The adequacy rate of the specimen and other clinical parameters were analyzed. The adequacy is defined as the target lesion is taken under ultrasound and specific diagnosis could be made by the specimen.ResultsThe overall diagnostic adequacy rate of USCB was 91%. Among different needle gauges of USCB, the 18-gauge group demonstrated a 100% adequate rate, a lower anesthetic demand (16.6%), and shorter postprocedure bleeding time (3.0 ± 1.4 minutes), showing significant differences when compared with others. No immediate or late complications were noted after procedure in all patients.ConclusionUSCB is minimally invasive and provides pathological information for diagnosis. It is a precise, safe, and office-based procedure and is suggested to be included in the diagnosis of head and neck tumors