Weak anti-localization in spin-orbit coupled lattice systems.

The quantum correction to electrical conductivity is studied on the basis of two-dimensional Wolff Hamiltonian, which is an effective model for a spin-orbit coupled (SOC) lattice system. It is shown that weak anti-localization (WAL) arises in SOC lattices, although its mechanism and properties are different from the conventional WAL in normal metals with SOC impurities. The interband SOC effect induces the contribution from the interband singlet Cooperon, which plays a crucial role for WAL in the SOC lattice. It is also shown that there is a crossover from WAL to weak localization in SOC lattices when the Fermi energy or band gap changes. The implications of the present results to Bi-Sb alloys and PbTe under pressure are discussed.

Crystalline spin-orbit interaction and the Zeeman splitting in Pb1-x Sn x Te.

The ratio of the Zeeman splitting to the cyclotron energy ([Formula: see text]), which characterizes the relative strength of the spin-orbit interaction in crystals, is examined for the narrow gap IV-VI semiconductors PbTe, SnTe, and their alloy Pb1-x Sn x Te on the basis of the multiband [Formula: see text] theory. The inverse mass α, the g-factor g, and M are calculated numerically by employing the relativistic empirical tight-binding band calculation. On the other hand, a simple but exact formula of M is obtained for the six-band model based on the group theoretical analysis. It is shown that M < 1 for PbTe and M > 1 for SnTe, which are interpreted in terms of the relevance of the interband couplings due to the crystalline spin-orbit interaction. It is clarified both analytically and numerically that M is not a quantized value but a continuous one, and M = 1 is obtained just at the band inversion point, where the transition from trivial to nontrivial topological crystalline insulator occurs. By using this property, one can detect the transition point only with the bulk measurements. It is also proposed that M is useful to evaluate quantitatively a degree of the Dirac electrons in solids.

Peat-fire-related air pollution in Central Kalimantan, Indonesia.

The past decade marked record high air pollution episodes in Indonesia. In this study, we specifically focus on vegetation fires in Palangkaraya located near a Mega Rice Project area in Indonesia. We analyzed various gaseous air pollution data such as particulate matter (PM10), SO2, CO, O3, and NO2 study region. We also conducted elemental analysis at two different sites. Results from 2001 to 2010 suggested the longest hazardous air pollution episode during 2002 lasting about 80 days from mid-August to late-October. Maximum peak concentrations of PM10, SO2, CO, and O3 were also observed during 2002 and their values reached 1905, 85.8, 38.3, and 1003×10(-6) gm(-3) respectively. Elemental analysis showed significant increase in concentrations during 2011 and 2010. Satellite retrieved fires and weather data could explain most of the temporal variations. Our results highlight peat fires as a major contributor of photochemical smog and air pollution in the region.

The effect of adjuvant 5'-deoxy-5-fluorouridine in early stage breast cancer patients: results from a multicenter randomized controlled trial.

To assess the efficacy of 5'-DFUR, an intermediate of capecitabine, for adjuvant treatment of early breast cancer, we conducted an open-labeled multi-center randomized controlled trial to compare postoperative 5'-DFUR treatment with surgery alone. We enrolled 1217 primary breast cancer patients and randomly assigned them into two treatment groups; one received six-month postoperative 5'-DFUR treatment by consecutive or intermittent administration, and the other surgery alone. Follow-up surveys were conducted once a year for all subjects simultaneously and examined their outcome/presence or absence of the cancer recurrence. The central study committee reviewed all follow-up data and judged the recurrence data to be used for the analysis. Eight-year follow-up data showed no significant differences in relapse-free and overall survival between the two groups, and 5'-DFUR treatment regimen showed an extremely high tolerance. Possible explanations are discussed for the finding of no significant survival difference between adjuvant 6-month 5'-DFUR monotherapy and surgery alone in early breast cancer.