613 research outputs found

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

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    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 (σxyH\sigma_{xy}^H) obtained from the GGA+U calculations with U=1.9U = 1.9 eV and J=1.2J=1.2 eV, is in nearly perfect agreement with that measured recently at low temperatures while, in contrast, the σxyH\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 3dd 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 σxyH\sigma_{xy}^H and the number of valence electrons (NeN_e) have also been calculated as a function of the Fermi energy (EFE_F). A sign change is predicted at EF=0.38E_F = -0.38 eV (Ne=9.57N_e = 9.57), and this explain qualitatively why the theoretical and experimental σxyH\sigma_{xy}^H values for Fe and Co are positive. It is also predicted that fcc Ni(1x)_{(1-x)}Co(Fe,Cu)x_x alloys with xx being small, would also have the negative σxyH\sigma_{xy}^H with the magnitude being in the range of 5001400500\sim 1400 Ω1\Omega^{-1}cm1^{-1}. The most pronounced effect of including the on-site Coulomb interaction is that all the dd-dominant bands are lowered in energy relative to the EFE_F by about 0.3 eV, and consequently, the small minority spin X2_2 hole pocket disappears. The presence of the small X2_2 hole pocket in the GGA calculations is attributed to be responsible for the large discrepancy in the σxyH\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

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    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

    Charged Higgs boson contribution to νˉee\bar{\nu}_e-e scattering from low to ultrahigh energy in Higgs triplet model

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    We study the νˉee\bar{\nu}_e-e scattering from low to ultrahigh energy in the framework of Higgs Triplet Model (HTM). We add the contribution of charged Higgs boson exchange to the total cross section of the scattering. We obtain the upper bound hee/MH±2.8×103GeV1h_{ee}/M_{H^\pm}\lesssim2.8\times10^{-3}GeV^{-1} in this process from low energy experiment. We show that by using the upper bound obtained, the charged Higgs contribution can give enhancements to the total cross section with respect to the SM prediction up to 5.16% at E1014E\leq10^{14} eV and maximum at sMH±2s\approx M_{H^\pm}^2 and would help to determine the feasibility experiments to discriminate between SM and HTM at current available facilities.Comment: 6 pages, 6 figure

    Radiation therapy for vaginal and perirectal lesions in recurrent ovarian cancer

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    The role for localized radiation to treat ovarian cancer (OC) patients with locally recurrent vaginal/perirectal lesions remains unclear, though we hypothesize these patients may be salvaged locally and gain long-term survival benefit. We describe our institutional outcomes using intensity modulated radiation therapy (IMRT) +/- high-dose rate (HDR) brachytherapy to treat this population. Our primary objectives were to evaluate complete response rates of targeted lesions after radiation and calculate our 5-year in-field control (IFC) rate. Secondary objectives were to assess radiation-related toxicities, chemotherapy free-interval (CFI), as well as post-radiation progression-free (PFS) and overall survival (OS). PFS and OS were defined from radiation start to either progression or death/last follow-up, respectively. This was a heavily pre-treated cohort of 17 recurrent OC patients with a median follow-up of 28.4 months (range 4.5-166.4) after radiation completion. 52.9% had high-grade serous histology and 4 (23.5%) had isolated vaginal/perirectal disease. Four (23.5%) patients had in-field failures at 3.7, 11.2, 24.5, and 27.5 months after start of radiation, all treated with definitive dosing of radiation therapy. Patients who were platinum-sensitive prior to radiation had similar median PFS (6.5 vs. 13.4 months, log-rank p = 0.75), but longer OS (71.1 vs 18.8 months, log-rank p = 0.05) than their platinum-resistant counterparts. Excluding patients with low-grade histology or who were treated with palliative radiation, median CFI was 14.2 months (range 4.7 - 33.0). Radiation was well tolerated with 2 (12.0%) experiencing grade 3/4 gastrointestinal/genitourinary toxicities. In conclusion, radiation to treat locally recurrent vaginal/perirectal lesions in heavily pre-treated OC patients is safe and may effectively provide IFC

    Quality of life and menopausal transition for middle-aged women on Kinmen island

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    Although it seems reasonable to suggest that most women experience significant changes in quality of life (QOL) during the menopausal period, few researchers have quantified these changes. A total of 1497 women, aged 40–54 years and living on the island of Kinmen, were recruited for this survey. However, 137 were eliminated leaving 1360 for analysis. Women who used hormonal therapy or who had undergone surgically induced menopause were excluded. The subjects with incomplete data or who exhibited mental retardation or severe psychiatric disease were also eliminated. Univariate analysis demonstrated that, in general, QOL scores were poorer for perimenopausal and postmenopausal status. Comparing pre- and postmenopausal women, significant statistical differences were demonstrated for role limitations due to physical and emotional problems, even after adjusting for age, education level, body mass index, menarche, and chronic illness. A strong association was demonstrated between menopausal symptoms and premens-trual syndrome (PMS). Women with menopausal symptoms and PMS had significantly lower scores on all SF-36 dimensions. The results of this study suggest that poorer health status is experienced by peri- and postmenopausal women compared to premenopausal women.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43564/1/11136_2004_Article_5091165.pd

    Methods and apparatus for constructing and implementing a universal extension module for processing objects in a database

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    Methods and apparatus for providing a multi-tier object-relational database architecture are disclosed. In one illustrative embodiment of the present invention, a multi-tier database architecture comprises an object-relational database engine as a top tier, one or more domain-specific extension modules as a bottom tier, and one or more universal extension modules as a middle tier. The individual extension modules of the bottom tier operationally connect with the one or more universal extension modules which, themselves, operationally connect with the database engine. The domain-specific extension modules preferably provide such functions as search, index, and retrieval services of images, video, audio, time series, web pages, text, XML, spatial data, etc. The domain-specific extension modules may include one or more IBM DB2 extenders, Oracle data cartridges and/or Informix datablades, although other domain-specific extension modules may be used

    Gynecologic oncology patient perspectives and knowledge on advance care planning: A quality improvement intervention

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    OBJECTIVES: Assess and improve advance care planning (ACP) awareness and uptake among gynecologic oncology patients. METHODS: Using a quality improvement Plan-Do-Check-Act framework, we completed a single institution needs assessment and intervention. The needs assessment was a 26-question survey assessing baseline ACP knowledge and preferences of gynecologic oncology patients. We used this survey to implement an outpatient intervention in which patients were offered ACP resources (pamphlet, discussion with their gynecologic oncologist, and/or social work referral). We conducted a post-intervention survey among patients who had and had not received ACP resource(s) to assess whether our intervention increased ACP knowledge, discussions, or uptake. RESULTS: Among 106 patients surveyed in the needs assessment, 33 % had ACP documents, 26 % had discussed ACP with a physician, and 82 % thought discussing ACP was important. The majority preferred these conversations in the outpatient setting (52 %) with their gynecologic oncologist (80 %) instead of nurses or trainees. In the intervention, 526 patients were offered ACP resources. Compared to women who did not receive resources (n = 324), patients who received ACP resource(s) (n = 202) were more likely to have ACP discussions with their gynecologic oncologist (38 % vs 68 %, CONCLUSIONS: ACP uptake among gynecologic oncology patients is low, but ACP discussions with an oncologist during outpatient visits are important to patients and improve their knowledge regarding completing ACP documents

    Knowledge and attitudes towards dementia in adolescent students

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    Background: Improving people’s knowledge, perceptions and attitudes of dementia is important in the formation of dementia-friendly communities. However, at present, there is very little evidence from adolescents, who are already the junior members of such communities and will be carers in their own rights in the future. Our aim was to evaluate adolescents’ knowledge and attitudes of dementia. Methods: Four-hundred and fifty adolescents, aged 15–18 years, from schools in Sussex (UK) were invited to complete a series of questions that assessed their dementia knowledge and attitudes. Results: A total of 359 adolescent students completed the questionnaire. Out of 15 questions on dementia knowledge, participants were on average able to answer less than half correctly (M = 6.65, standard deviation = 2.34). Responses to the attitudes questionnaire showed that adolescent students had both positive and negative attitudes toward dementia. Discussion: There is scope for adolescents attending school to improve their dementia knowledge and attitudes. More effort is needed to embed initial dementia understanding in the school curriculum which will improve awareness about dementia at an earlier age and will enhance dementia-friendly communities
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