208 research outputs found

    Coherent single electron spin control in a slanting Zeeman field

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    We consider a single electron in a 1D quantum dot with a static slanting Zeeman field. By combining the spin and orbital degrees of freedom of the electron, an effective quantum two-level (qubit) system is defined. This pseudo-spin can be coherently manipulated by the voltage applied to the gate electrodes, without the need for an external time-dependent magnetic field or spin-orbit coupling. Single qubit rotations and the C-NOT operation can be realized. We estimated relaxation (T1T_1) and coherence (T2T_{2}) times, and the (tunable) quality factor. This scheme implies important experimental advantages for single electron spin control.Comment: 4 pages, 3 figure

    Systematic Control of Strain-Induced Perpendicular Magnetic Anisotropy in Epitaxial Europium and Terbium Iron Garnets Thin Films

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    We show tunable strain-induced perpendicular magnetic anisotropy (PMA) over a wide range of thicknesses in epitaxial ferrimagnetic insulator Eu3Fe5O12 (EuIG) and Tb3Fe5O12 (TbIG) thin films grown by pulsed-laser deposition on Gd3Ga5O12 with (001) and (111) orientations, respectively. The PMA field is determined by measuring the induced anomalous Hall loops in Pt deposited on the garnet films. Due to positive magnetostriction constants, compressive in-plane strain induces a PMA field as large as 32.9 kOe for 4 nm thick EuIG and 66.7 kOe for 5 nm thick TbIG at 300 K, and relaxes extremely slowly as the garnet film thickness increases. In bilayers consisting of Pt and EuIG or Pt and TbIG, robust PMA is revealed by squared anomalous Hall hysteresis loops in Pt, the magnitude of which appears to be only related to the net magnetic moment of iron sublattices. Furthermore, the magnetostriction constant is found to be 2.7x10^(-5) for EuIG and 1.35x10^(-5) for TbIG, comparable with the values for bulk crystals. Our results demonstrate a general approach of tailoring magnetic anisotropy of rare earth iron garnets by utilizing modulated strain via epitaxial growth

    Synchronous bilateral pheochromocytomas and paraganglioma with novel germline mutation in MAX: a case report

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    BackgroundRecent advance of genetic testing has contributed to the diagnosis of hereditary pheochromocytoma and paraganglioma (PPGL). The clinical characteristics of hereditary PPGL are varying among the types of mutational genes. It is still difficult to specify the pathognomonic symptoms in the case of rare genetic mutations. Here, we report the case of synchronous bilateral pheochromocytomas and paraganglioma with novel MYC associated factor X (MAX) gene mutation.Case presentationA 24-year-old female had hyperhidrosis and hypertension. Her urine test showed high normetanephrine and vanillylmandelic acid. Enhanced computed tomography revealed three enhanced masses in right adrenal gland, left adrenal gland, and left renal hilus. She was diagnosed with PPGL. Because 123I-metaiodobenzylguanidine scintigraphy indicated the accumulations in the left adrenal gland mass and the left renal hilus mass and not in the right adrenal gland mass, we performed laparoscopic left adrenalectomy and extirpation of the left renal hilus mass to preserve the right adrenocortical function. However, her symptoms recurred shortly after the operation presumably due to unveiling of the activity of the right pheochromocytoma. Following right adrenalectomy as the second operation, the catecholamine levels declined to normal range. Her genetic testing indicated the novel germline mutation in MAX gene (c.70_73 del AAAC/p.Lys24fs*40).ConclusionsMAX germline mutation is recently identified as a rare cause of hereditary PPGL. The deletion mutation in MAX gene in this patient has never reported before. In the case of bilateral pheochromocytomas, the surgical indication should be decided considering each patient’s genetic background. Due to the possibility for other types of malignant tumors, close follow-up is essential for MAX mutation carriers

    Multicenter Phase II Study of Intravenous and Intraperitoneal Paclitaxel With S-1 for Pancreatic Ductal Adenocarcinoma Patients With Peritoneal Metastasis

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    OBJECTIVE:To evaluate the clinical efficacy and tolerability of intravenous (i.v.) and intraperitoneal (i.p.) paclitaxel combined with S-1, "an oral fluoropyrimidine derivative containing tegafur, gimestat, and otastat potassium" in chemotherapy-naive pancreatic ductal adenocarcinoma (PDAC) patients with peritoneal metastasis.BACKGROUND:PDAC patients with peritoneal metastasis (peritoneal deposits and/or positive peritoneal cytology) have an extremely poor prognosis. An effective treatment strategy remains elusive.METHODS:Paclitaxel was administered i.v. at 50 mg/m and i.p. at 20 mg/m on days 1 and 8. S-1 was administered at 80 mg/m/d for 14 consecutive days, followed by 7 days of rest. The primary endpoint was 1-year overall survival (OS) rate. The secondary endpoints were antitumor effect and safety (UMIN000009446).RESULTS:Thirty-three patients who were pathologically diagnosed with the presence of peritoneal dissemination (n = 22) and/or positive peritoneal cytology (n = 11) without other organ metastasis were enrolled. The tumor was located at the pancreatic head in 7 patients and the body/tail in 26 patients. The median survival time was 16.3 (11.47-22.57) months, and the 1-year survival rate was 62%. The response rate and disease control rate in assessable patients were 36% and 82%, respectively. OS in 8 patients who underwent conversion surgery was significantly higher than that of nonsurgical patients (n = 25, P = 0.0062). Grade 3/4 hematologic toxicities occurred in 42% of the patients and nonhematologic adverse events in 18%. One patient died of thrombosis in the superior mesenteric artery.CONCLUSIONS:This regimen has shown promising clinical efficacy with acceptable tolerability in chemotherapy-naive PDAC patients with peritoneal metastasis

    Chromobox 2 Expression Predicts Prognosis after Curative Resection of Oesophageal Squamous Cell Carcinoma

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    Background/Aim: To investigate the function of chromobox 2 (CBX2) in oesophageal squamous cell carcinoma (OSCC). Materials and Methods: We used real-time quantitative reverse transcription PCR (qRT-PCR) and immunohisto - chemistry to determine CBX2 expression levels in 13 human OSCC cell lines and clinical specimens of two independent cohorts of patients with OSCC. Results: PCR array analysis revealed that CBX2 was co-ordinately expressed with WNT5B in OSCC cell lines. RT-qPCR analysis of clinical samples revealed a high tumour-specific CBX2 expression compared with normal oesophageal tissues. High CBX2 expression was significantly associated with shorter disease-specific survival, hematogenous recurrence, and overall recurrence. Analysis of tissue microarrays of one cohort revealed that patients with higher CBX2 levels tended to have a shorter disease-specific survival. Conclusion: CBX2 overexpression in OSCC tissues may serve as a novel biomarker for predicting survival and hematogenous recurrence
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