In-plane ferromagnetism in charge-ordering Na0.55CoO2Na_{0.55}CoO_2

The magnetic and transport properties are systematically studied on the single crystal $Na_{0.55}CoO_2$ with charge ordering and divergency in resistivity below 50 K. A long-range ferromagnetic ordering is observed in susceptibility below 20 K with the magnetic field parallel to Co-O plane, while a negligible behavior is observed with the field perpendicular to the Co-O plane. It definitely gives a direct evidence for the existence of in-plane ferromagnetism below 20 K. The observed magnetoresistance (MR) of 30 % at the field of 6 T at low temperatures indicates an unexpectedly strong spin-charge coupling in triangle lattice systems.Comment: 4 pages, 5 figure

Mixed-Spin Pairing Condensates in Heavy Nuclei

We show that the Bogoliubov-de Gennes equations for nuclear ground-state wave functions support solutions in which the condensate has a mixture of spin-singlet and spin-triplet pairing. We find that such mixed-spin condensates do not occur when there are equal numbers of neutrons and protons, but only when there is an isospin imbalance. Using a phenomenological Hamiltonian, we predict that such nuclei may occur in the physical region within the proton dripline. We also solve the Bogoliubov-de Gennes equations with variable constraints on the spin-singlet and spin-triplet pairing amplitudes. For nuclei that exhibit this new pairing behavior, the resulting energy surface can be rather soft, suggesting that there may be low-lying excitations associated with the spin mixing.Comment: 4+ pages, 3 figures, 1 table; 1 reference added; v2 corresponds to the published versio

Integer quantum Hall effect and topological phase transitions in silicene

We numerically investigate the effects of disorder on the quantum Hall effect (QHE) and the quantum phase transitions in silicene based on a lattice model. It is shown that for a clean sample, silicene exhibits an unconventional QHE near the band center, with plateaus developing at $\nu=0,\pm2,\pm6,\ldots,$ and a conventional QHE near the band edges. In the presence of disorder, the Hall plateaus can be destroyed through the float-up of extended levels toward the band center, in which higher plateaus disappear first. However, the center $\nu=0$ Hall plateau is more sensitive to disorder and disappears at a relatively weak disorder strength. Moreover, the combination of an electric field and the intrinsic spin-orbit interaction (SOI) can lead to quantum phase transitions from a topological insulator to a band insulator at the charge neutrality point (CNP), accompanied by additional quantum Hall conductivity plateaus.Comment: 7 pages, 4 figure

Synergistic effect of radiation and traditional Chinese medicine Rhizomatyphonii ethanol extracts depends on P53 expression in treatment of Lewis mouse lung cancer cells

Background: Lung cancer is the leading cause of cancer-related death, and it is the most common cancer in terms of both incidence and mortality. There is an urgent need on novel therapeutic strategies for lung cancer. Traditional Chinese herbal medicines (CHM) have potential valuable for cancer treatment.Materials and Methods: Lewis mouse lung cancer cell line and Lewis cells tumors xenograft were used in this experiment. MTT assay was used to detect cell proliferation, flow cytometry (FCM) analysis and Western blotting to detect cell apoptosis, and colony formation assay to evaluate the effect of combined therapy of RT+IR.Results: Our data showed that Rhizoma typhonii (RT) obviously inhibited the proliferations of Lewis cells in time and dose dependent manners by MTT assay and enhanced radiosensitivity by colony formation assay. The effects of RT to Ionizing radiation (IR) therapy were demonstrated radiosensitivity on tumors xenograft experiment. In our study, RT induced apoptotic in Lewis cells directly and enhanced the pro-apoptotic effect of IR by regulating the expression of p53.Conclusions: These data suggested that RT may be a great potential anti-tumor medicine and the combination of RT and IR may provide a new therapeutic strategy for the treatment of Lewis lung cancer.Keywords: Rhizoma Typhonii, Radiation, Lung cancer, Combined therapy, Apoptosi

Evidence of s-wave pairing symmetry in layered superconductor Li0.68_{0.68}NbO2_2 from the specific heat measurement

A high quality superconducting Li$_{0.68}$NbO$_2$ polycrystalline sample was synthesized by deintercalation of Li ions from Li$_{0.93}$NbO$_2$. The field dependent resistivity and specific heat were measured down to 0.5 K. The upper critical field $H_{c2} (T)$ is deduced from the resistivity data and $H_{c2}(0)$ is estimated to be $\sim 2.98$ T. A notable specific heat jump is observed at the superconducting transition temperature $T_c \sim 5.0$ K at zero field. Below $T_c$, the electronic specific heat shows a thermal activated behavior and agrees well with the theoretical result of the BCS s-wave superconductors. It indicates that the superconducting pairing in Li$_{0.68}$NbO$_2$ has s-wave symmetry.Comment: 4 pages, 5 figure