283 research outputs found

    Spin torque ferromagnetic resonance with magnetic field modulation

    Full text link
    We demonstrate a technique of broadband spin torque ferromagnetic resonance (ST-FMR) with magnetic field modulation for measurements of spin wave properties in magnetic nanostructures. This technique gives great improvement in sensitivity over the conventional ST-FMR measurements, and application of this technique to nanoscale magnetic tunnel junctions (MTJs) reveals a rich spectrum of standing spin wave eigenmodes. Comparison of the ST-FMR measurements with micromagnetic simulations of the spin wave spectrum allows us to explain the character of low-frequency magnetic excitations in nanoscale MTJs.Comment: Also see: http://faculty.sites.uci.edu/krivorotovgroup

    Radiation Heating of Primary Collimators at Ramping

    Get PDF
    A time-dependent temperature map is derived for the primary jaw of the momentum collimation system during the high transient loss period which is to occur at the beginning of the ramp of acceleration. An adequate margin factor is obtained for a loss of 5% of the nominal stored beam and for the nominal parabolic ramping curve

    Magnetic phase transitions in Ta/CoFeB/MgO multilayers

    Full text link
    We study thin films and magnetic tunnel junction nanopillars based on Ta/Co20_{20}Fe60_{60}B20_{20}/MgO multilayers by electrical transport and magnetometry measurements. These measurements suggest that an ultrathin magnetic oxide layer forms at the Co20_{20}Fe60_{60}B20_{20}/MgO interface. At approximately 160 K, the oxide undergoes a phase transition from an insulating antiferromagnet at low temperatures to a conductive weak ferromagnet at high temperatures. This interfacial magnetic oxide is expected to have significant impact on the magnetic properties of CoFeB-based multilayers used in spin torque memories

    Возможности сфинктеросохраняющего лечения больных местно-распространенным первично-неоперабельным раком прямой кишки

    Get PDF
    The aim of this study was to compare results of sphincter-sparing operations (SSO) and abdominoperineal resections (APR) in patients  undergoing combined treatment for unresectable locally-advanced rectal cancer.Methods. During September 2007 – January 2011 59 patients were enrolled. Original treatment scheme (RF patent № 2414936) was developed including radiotherapy 40 Gy in 4 Gy fractions, capecitabine 650 mg/m2 bid per os days 1-22, oxaliplatin 50 mg/m2 iv days 3, 10, 17, local hyperthermia on days 8, 12, 15, 17, 2 applications of metronidazole 10 g/m2 per rectum in a polymeric composition. Surgery was carried out following 6–8 weeks. SSO were carried out in 36 patients, APR in 23 patients. Study endpoints included 2-year OS and DFS, local recurrence and distant metastases rate, postoperative complications rate.Results. No significant differences in survival were observed: 2-year OS was 93.2 and 85.6 % (log- rank test p = 0.157) for SSO and APR groups accordingly, 2-year DFS was 88 and 71.9 % (log-rank test p = 0.064). Four (11.1 %) patients in SSO group and 4 (17.4 %) patients in APR group (р = 0.5511) developed local recurrences, 4 (11.1 %) and 7 (30.4 %) (р = 0.1293) developed distant metastases. Postoperative complications rate was 27.8 % (n = 10) and 39.1 % (n = 9) (р = 0.5181) in SSO and APR groups accordingly.Conclusions. Sphincter-sparting surgery is justified for unresectable locally advanced rectal cancer when technically feasible

    Femtomolar detection of the heart failure biomarker NT-proBNP in artificial saliva using an immersible liquid-gated aptasensor with reduced graphene oxide

    Full text link
    Measuring NT-proBNP biomarker is recommended for preliminary diagnostics of the heart failure. Recent studies suggest a possibility of early screening of biomarkers in saliva for non-invasive identification of cardiac diseases at the point-of-care. However, NT-proBNP concentrations in saliva can be thousand time lower than in blood plasma, going down to pg/mL level. To reach this level, we developed a label-free aptasensor based on a liquid-gated field effect transistor using a film of reduced graphene oxide monolayer (rGO-FET) with immobilized NT-proBNP specific aptamer. We found that, depending on ionic strength of tested solutions, there were different levels of correlation in responses of electrical parameters of the rGO-FET aptasensor, namely, the Dirac point shift and transconductance change. The correlation in response to NT-proBNP was high for 1.6 mM phosphate-buffered saline (PBS) and zero for 16 mM PBS in a wide range of analyte concentrations, varied from 1 fg/mL to 10 ng/mL. The effects of transconductance and Dirac point shift in PBS solutions of different concentrations are discussed. The biosensor exhibited a high sensitivity for both transconductance (2 uS/decade) and Dirac point shift (2.3 mV/decade) in diluted PBS with the linear range from 10 fg/mL to 1 pg/mL. The aptasensor performance has been also demonstrated in undiluted artificial saliva with the achieved limit of detection down to 41 fg/mL (~4.6 fM)

    A RARE CASE OF TREATMENT POLICY FOR RECURRENT NEUROENDOCRINE CARCINOMA OF THE ANAL CANAL

    Get PDF
    A rare case of multicomponental treatment of low-differentiated anal neuroendocrine cancer is presented. By using combined treatment involving chemotherapy, local hyperthermia and radiotherapy a complete response of recurrent neuroendocrine cancer has been achieved.A review of modern methods of diagnostics and treatment of rectal neurtoendocrine tumors is presented and possibilities of modern combined treatment are discussed
    corecore