Interplay of the charge density wave transition with topological and superconducting properties.

Exotic phenomena due to the interplay of different quantum orders have been observed and the study of these phenomena has emerged as a new frontier in condensed matter research, especially in the two-dimensional limit. Here, we report the coexistence of charge density waves (CDWs), superconductivity, and nontrivial topology in monolayer 1H-MSe2 (M = Nb, Ta) triggered by momentum-dependent electron-phonon coupling through electron doping. At a critical electron doping concentration, new 2 × 2 CDW phases emerge with nontrivial topology, Dirac cones, and van Hove singularities. Interestingly, these 2 × 2 CDW phases are also superconducting. Our findings not only reveal a route towards realizing nontrivial electronic characters by CDW engineering, but also provide an exciting platform to modulate different quantum states at the confluence of CDWs, superconductivity, nontrivial topology, and electron-phonon coupling.

[Comparison of diagnostic value between DR and MSCT in fracture and dislocation of foot and ankle].

OBJECTIVE: To compare the diagnostic value between digital photography (DR) and multi-slice spiral CT (MSCT) in fracture and dislocation of foot and ankle. METHODS: From August 2010 to August 2012, the DR and MSCT data of 52 patients with fracture and dislocation of foot and ankle were compared according to results of surgery or discharge diagnosis. There were 37 males and 15 females, aged from 15 to 49 years old. Wilcoxon signed rank test was used for statistical analysis. RESULTS: The results of 52 cases of MSCT were matched with the postoperative or discharge diagnosis. A total of 172 fractures were found on MSCT and 98 fractures were found on DR, the results had significant difference in detecting fracture (V=1 081, P<0.05); A total of 24 dislocations were found on MSCT and 16 dislocations were found on DR,the results also had significant difference in detecting dislocation (V=21, P<0.05). Fractures of 6 cases with DR diagnosis were corrected and located by MSCT. CONCLUSION: MSCT is significantly better than DR in diagnosis of fracture and dislocation of foot and ankle. The examination of two parts should be performed in DR. MSCT and multi-planar reconstruction (MPR) examination should be further performed if DR results are unclear or do not match with clinical symptoms, missed diagnosis and misdiagnosis can be avoided.