Heavy surface state in a possible topological Kondo insulator: Magneto-thermoelectric transport on the (011)-plane of SmB6_6

Motivated by the high sensitivity to Fermi surface topology and scattering mechanisms in magneto-thermoelectric transport, we have measured the thermopower and Nernst effect on the (011)-plane of the proposed topological Kondo insulator SmB$_6$. These experiments, together with electrical resistivity and Hall effect measurements, demonstrate that the (011)-plane also harbors a metallic surface with the effective mass in the order of 10-10$^2$ $m_0$. The surface and bulk conductances are well distinguished in these measurements and are categorized into metallic and non-degenerate semiconducting regimes, respectively. Electronic correlations play an important role in enhancing scattering and also contribute to the heavy surface state.Comment: 4 figures, 1 tabl

Covert Laparoscopic Cholecystectomy: A New Minimally Invasive Technique

To further improve our developed transumbilical endoscopic surgery (TUES), we developed a completely covert laparoscopic cholecystectomy (LC). Twelve cases of LC were recruited for this new approach. First, a 10-mm trocar was placed above the umbilicus for inserting the laparoscope. Two 5-mm trocars were then placed near the right and left ends of the superior margin of the suprapubic hair. After the 5-mm 30° laparoscope was shifted to the left suprapubic trocar, the harmonic scalper, electric hook, and grasper were inserted either through the 10-mm umbilical trocar or through the right suprapubic trocar. All gallbladders were successfully removed without intraoperative complications. The mean operating time was 28.5±5.7min (range 20-45min). All patients felt well after surgery and did not need postoperative analgesia. They resumed free oral intake 6h after the procedure. All patients were satisfied with the appearance of the incisions, which were completely hidden in the umbilicus and suprapubic hair. The approach we developed has overcome both external instrument interference around the umbilicus and the loss of triangulation in the operative field. It is relatively simpler than a typical TUES and offers better cosmetic results

Protective Effect of Anthocyanins Extract from Blueberry on TNBS-Induced IBD Model of Mice

This study was carried out to evaluate the protective effect of anthocyanins extract of blueberry on trinitrobenzene sulfonic acid (TNBS)-induced inflammatory bowel disease (IBD) model of mice. The study employed female C57BL/6 mice (n = 50), and colitis was induced by intracolonic injection of 0.5 mg of TNBS dissolved in 50% ethanol–phosphate buffered solution. The mice were divided into five groups (n = 10): vehicle, TNBS control and anthocyanins groups that received different doses of anthocyanins extract (10, 20 and 40 mg kg−1) daily for 6 days. Both increase in body weight and diarrhea symptoms were monitored each day. After 6 days, the animals were killed, and the following parameters were assessed: colon length, morphological score, histological score and biochemical assay (NO, myeloperoxidase (MPO), interleukin (IL)-12, IL-10, tumor necrosis factor (TNF)-α and interferon (IFN)-γ). The results showed that the anthocyanins extract of blueberry rendered strong protection against TNBS-induced colonic damage at a dosage of 40 mg kg−1. When compared with the control, anthocyanins extract significantly prevented loss of body weight and ameliorated the scores of diarrhea, morphology and histology. Treatment with anthocyanins extract restored IL-10 excretion, as well as caused reduction in the levels of NO, MPO, IL-12, TNF-α and IFN-γ. Our research revealed the protective effect of anthocyanins extract from blueberry on TNBS-induced experimental colitis in mice, as well as examined whether high levels of dietary blueberries would lower the risk or have protective effects on human IBD, which may require further investigation

Pressure induced superconductivity bordering a charge-density-wave state in NbTe4 with strong spinorbit coupling

Transition-metal chalcogenides host various phases of matter, such as charge-density wave (CDW), superconductors, and topological insulators or semimetals. Superconductivity and its competition with CDW in low-dimensional compounds have attracted much interest and stimulated considerable research. Here we report pressure induced superconductivity in a strong spin-orbit (SO) coupled quasi-one-dimensional (1D) transition-metal chalcogenide NbTe$_4$, which is a CDW material under ambient pressure. With increasing pressure, the CDW transition temperature is gradually suppressed, and superconducting transition, which is fingerprinted by a steep resistivity drop, emerges at pressures above 12.4 GPa. Under pressure $p$ = 69 GPa, zero resistance is detected with a transition temperature $T_c$ = 2.2 K and an upper critical field $H_{c2}$= 2 T. We also find large magnetoresistance (MR) up to 102\% at low temperatures, which is a distinct feature differentiating NbTe$_4$ from other conventional CDW materials.Comment: https://rdcu.be/LX8