Effect of high annealing temperature on giant tunnel magnetoresistance ratio of CoFeB/MgO/CoFeB magnetic tunnel junctions

We report tunnel magnetoresistance (TMR) ratios as high as 472% at room temperature and 804% at 5 K in pseudo-spin valve (SV) CoFeB/MgO/CoFeB magnetic tunnel junctions (MTJs) annealed at 450oC, which is approaching the theoretically predicted value. By contrast, the TMR ratios for exchange-biased (EB) SV MTJs with a MnIr antiferromagnetic layer are found to drop when they are annealed at 450oC. Energy dispersive X-ray analysis shows that annealing at 450oC induces interdiffusion of Mn and Ru atoms into the MgO barrier and ferromagnetic layers in EB-SV MTJs. Mechanisms behind the different annealing behavior are discussed.Comment: 13 pages, 5 figure

Dependence of tunnel magnetoresistance on ferromagnetic electrode materials in MgO-barrier magnetic tunnel junctions

We investigated the relationship between the tunnel magnetoresistance (TMR) ratio and the electrode structure in MgO-barrier magnetic tunnel junctions (MTJs). The TMR ratio in a MTJ with Co40Fe40B20 reference and free layers reached 355% at the post-deposition annealing temperature of Ta=400 degree C. When Co50Fe50 or Co90Fe10 is used for the reference layer material, no high TMR ratio was observed. The key to have high TMR ratio is to have highly oriented (001) MgO barrier/CoFeB crystalline electrodes. The highest TMR ratio obtained so far is 450% at Ta = 450 degree C in a pseudo spin-valve MTJ.Comment: 6 pages, 2 figures, 1 table. to be published in J. Magn. Magn. Mate

Long-term survival after an aggressive surgical resection and chemotherapy for stage IV pulmonary giant cell carcinoma

BACKGROUND: Pulmonary giant cell carcinoma is one of the rare histological subtypes with pleomorphic, sarcomatoid or sarcomatous elements. The prognosis of patients with this tumor tends to be poor, because surgery, irradiation and chemotherapy are not usually effective. CASE PRESENTATION: We herein report a patient with pulmonary giant cell carcinoma with stage IV disease in whom aggressive multi-modality therapy resulted in a long-term survival. A 51-year-old male underwent an emergent operation with a partial resection of small intestinal metastases due to bleeding from the tumor. The patient also underwent a left pneumonectomy due to hemothorax as a result of the rapid growth of the primary tumor. Thereafter, two different regimens of chemotherapy and a partial resection for other site of small intestinal metastases and a splenectomy for splenic metastases were performed. The patient is presently doing well without any evidence of recurrence for 3 years after the initial operation. CONCLUSION: This is a first report of a rare case with stage IV pulmonary giant cell carcinoma who has survived long-term after undergoing aggressive surgical treatment and chemotherapy

Dependence of Giant Tunnel Magnetoresistance of Sputtered CoFeB/MgO/CoFeB Magnetic Tunnel Junctions on MgO Barrier Thickness and Annealing Temperatur

We investigated the dependence of giant tunnel magnetoresistance (TMR) on the thickness of an MgO barrier and on the annealing temperature of sputtered CoFeB/MgO/CoFeB magnetic tunnel junctions deposited on SiO2/Si wafers. The resistance-area product exponentially increases with MgO thickness, indicating that the quality of MgO barriers is high in the investigated thickness range of 1.15-2.4 nm. High-resolution transmission electron microscope images show that annealing at 375 C results in the formation of crystalline CoFeB/MgO/CoFeB structures, even though CoFeB electrodes are amorphous in the as-sputtered state. The TMR ratio increases with annealing temperature and is as high as 260% at room temperature and 403% at 5 K.Comment: 12 pages, 5 figure

気管支喘息患者の血清コーチゾール値について. 副腎皮質ホルモン投与および年齢との関連

Serum cortisol levels were examined in 94 patients with bronchial asthma in relation to dose of glucocorticoids and age. 1. The level of serum cortisol was significantly lower in group A patients, treated with glucocorticoids (prednisolone of 5mg/day or more) for more than 2 years, (2.4±1.2mcg/㎗) than in group B, treated with glucocorticoids (prednisolone of 5mg or less) for less than 2 years, (6.8±3.7mcg/㎗) (p<0.001) and in group C, treated without glucocorticoids, (12.6±3.9mcg/㎗) (p<0.001). The serum cortisol level was also significantly lower in group B than in group C (p<0.001). 2. The level of serum cortisol was significantly lower in patients over the age of 70 compared to that in those aged between 0 and 39 years (p<0.01) and those between 40 and 49 (p<0.05), and those between 50 and 59 (p<0.02). The level was also lower in patients between 60 and 69 compared to that in those between 0 and 39, however, this was not significant. These results demonstrate that the level of serum cortisol decreases by long-term glucocorticoid regimen and with aging.気管支喘息94例を対象に,副腎皮質ホルモン投与および年齢との関連のもとに,血清コーチゾール値の変動を観察した｡まず副腎皮質ホルモンの投与量および投与期間により以下の3群に分けて検討した｡グループA :副腎皮質ホルモン,プレドニソロンに換算して1日5mg以上を2年間以上にわたり使用している症例,グループB:プレドニソロン1日5mg以下で2年間以内の使用症例, グループC:副腎皮質ホルモンを全く使用していない症例｡その結果,グループAの血清コーチゾ-ル値(2.4±1.2mcg/㎗)は,グループB (6.8±3.7mcg/㎗)(p 0.01)やC(12.6±3.9mcg/㎗)(p 0.001)に比べ有意に低い値であった｡2､グループCでは,70才以上の症例の血清コーチゾ-ル値は,0-39才の症例(p 0.0l),40-49才の症例(p 0.05),そして,50-59才の症例(p 0.02)に比べ有意に低い値であった｡これらの結果は,血清コーチゾール値は,副腎 皮質ホルモンの投与量や投与期間以外にも､加齢による影響を受ける可能性を示唆している