Intrinsic anomalous Hall effect in nickel: An GGA+U study

The electronic structure and intrinsic anomalous Hall conductivity of nickel have been calculated based on the generalized gradient approximation (GGA) plus on-site Coulomb interaction (GGA+U) scheme. It is found that the intrinsic anomalous Hall conductivity ($\sigma_{xy}^H$) obtained from the GGA+U calculations with $U = 1.9$ eV and $J=1.2$ eV, is in nearly perfect agreement with that measured recently at low temperatures while, in contrast, the $\sigma_{xy}^H$ from the GGA calculations is about 100% larger than the measured one. This indicates that, as for the other spin-orbit interaction (SOI)-induced phenomena in 3$d$ itinerant magnets such as the orbital magnetic magnetization and magnetocrystalline anisotropy, the on-site electron-electron correlation, though moderate only, should be taken into account properly in order to get the correct anomalous Hall conductivity. The intrinsic $\sigma_{xy}^H$ and the number of valence electrons ($N_e$) have also been calculated as a function of the Fermi energy ($E_F$). A sign change is predicted at $E_F = -0.38$ eV ($N_e = 9.57$), and this explain qualitatively why the theoretical and experimental $\sigma_{xy}^H$ values for Fe and Co are positive. It is also predicted that fcc Ni$_{(1-x)}$Co(Fe,Cu)$_x$ alloys with $x$ being small, would also have the negative $\sigma_{xy}^H$ with the magnitude being in the range of $500\sim 1400$ $\Omega^{-1}$cm$^{-1}$. The most pronounced effect of including the on-site Coulomb interaction is that all the $d$-dominant bands are lowered in energy relative to the $E_F$ by about 0.3 eV, and consequently, the small minority spin X$_2$ hole pocket disappears. The presence of the small X$_2$ hole pocket in the GGA calculations is attributed to be responsible for the large discrepancy in the $\sigma_{xy}^H$ between theory and experiment.Comment: 7 pages, 3 figures; Accepted for publication in Physical Review

AXL modulates extracellular matrix protein expression and is essential for invasion and metastasis in endometrial cancer

The receptor tyrosine kinase AXL promotes migration, invasion, and metastasis. Here, we evaluated the role of AXL in endometrial cancer. High immunohistochemical expression of AXL was found in 76% (63/83) of advanced-stage, and 77% (82/107) of high-grade specimens and correlated with worse survival in uterine serous cancer patients. In vitro, genetic silencing of AXL inhibited migration and invasion but had no effect on proliferation of ARK1 endometrial cancer cells. AXL-deficient cells showed significantly decreased expression of phospho-AKT as well as uPA, MMP-1, MMP-2, MMP-3, and MMP-9. In a xenograft model of human uterine serous carcinoma with AXL-deficient ARK1 cells, there was significantly less tumor burden than xenografts with control ARK1 cells. Together, these findings underscore the therapeutic potentials of AXL as a candidate target for treatment of metastatic endometrial cancer

The role of endometrial sampling for surveillance of recurrence in postmenopausal patients with medically inoperable stage I endometrial cancer

It is unclear if surveillance for postmenopausal women with medically inoperable stage 1 endometrial cancer (EC) should differ depending on their management strategy. Thus, we investigated the utility of surveillance endometrial sampling among 53 postmenopausal women with medically inoperable, clinical stage I, grade 1 endometrioid EC who received either progestin therapy or radiation between 2009 and 2018, at a single academic institution. Frequency and results of endometrial sampling, as well as recurrence and survival rates were studied. Of 53 patients, 18 (34.0%) received progestin therapy and 35 (66.0%) radiation. Medically managed patients were treated with megestrol acetate (27.7%), a levonorgestrel intrauterine device (27.7%), or both (44.4%). Radiated patients were mostly treated with high-dose rate brachytherapy only (77.1%). Surveillance endometrial sampling (median procedures = 4, range 1-10) was strictly adhered to among all patients who received progestin therapy, but infrequently (6/35, 17.1%) performed among radiated patients, yielding no positive results. Three recurrences occurred over the median follow-up of 38 months. Two (11%) women in the progestin therapy group recurred locally and were diagnosed by endometrial sampling. One (3%) patient in the radiation group recurred distally in the lung 25.3 months after completing brachytherapy. We conclude that appropriate surveillance for women with medically inoperable, clinical stage I, grade 1 EC depends on the management strategy. For those treated with progestins, surveillance with endometrial sampling every 3-6 months can reveal local recurrence. However, given the excellent local control after radiation, endometrial sampling may not be warranted for women treated with definitive radiation