413 research outputs found

    Measurement-free topological protection using dissipative feedback

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    Protecting quantum information from decoherence due to environmental noise is vital for fault-tolerant quantum computation. To this end, standard quantum error correction employs parallel projective measurements of individual particles, which makes the system extremely complicated. Here we propose measurement-free topological protection in two dimension without any selective addressing of individual particles. We make use of engineered dissipative dynamics and feedback operations to reduce the entropy generated by decoherence in such a way that quantum information is topologically protected. We calculate an error threshold, below which quantum information is protected, without assuming selective addressing, projective measurements, nor instantaneous classical processing. All physical operations are local and translationally invariant, and no parallel projective measurement is required, which implies high scalability. Furthermore, since the engineered dissipative dynamics we utilized has been well studied in quantum simulation, the proposed scheme can be a promising route progressing from quantum simulation to fault-tolerant quantum information processing.Comment: 17pages, 6 figure

    The relation between visceral adipose tissue accumulation and biochemical tests in university students.

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    We evaluated the visceral adipose tissue accumulation in university students in Okayama prefecture, Japan. Fifty-eight Japanese university students (10 men and 48 women, age 18.4 +/- 0.6 years)were enrolled in this study. Fat distribution was evaluated by visceral fat (V) and subcutaneous fat (S) areas measured with computed tomography (CT) scanning at umbilical levels. Anthropometric parameters,i.e., height, weight, waist circumference, hip circumference, and body fat percentage; blood examination; and blood pressure (BP) were also measured. In 58 subjects, the V area was 23.4 +/- 21.0 cm(2) and the S area was 122.5 +/- 57.9 cm(2). V areas were significantly correlated with hepatic enzymes, uric acid, triglyceride, and BP in men, while they were weakly correlated with hepatic enzymes, triglyceride, and high density lipoprotein (HDL) cholesterol in women. Correlation coefficients between V areas and clinical parameters were comparatively higher than those between other body composition parameters,i.e., S areas, weight, body mass index (BMI), body fat percentage, and clinical parameters. The present study suggests that visceral adipose tissue accumulation is important for hepatic enzymes, uric acid, triglyceride, and BP in university students.</p

    Clinical Features of Oral Multiple Primary Carcinomas Compared with Oral Single Primary Carcinoma

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    [Background] Owing to the increase in the older population and the increased life span, the number of patients with oral multiple primary carcinomas will increase. Predicting the second and third carcinoma clinically is difficult, and the presence of second or third carcinomas is a factor that determines the prognosis of oral carcinoma. In this study, we examined the clinical features of oral multiple primary carcinomas treated in our department. [Methods] We retrospectively reviewed the medical records of patients with oral squamous cell carcinoma who underwent radical treatment at and were followed by the Department of Oral and Maxillofacial Surgery, Tottori University Hospital from January 2003 to October 2017. [Results] This study included 261 patients: 241 patients had oral single primary carcinoma and 20 patients had oral multiple primary carcinomas. Oral multiple primary carcinomas showed female predilection and occurred more frequently in the lower gingiva and significantly less frequently in the tongue (P < 0.01). Oral multiple primary carcinomas showed a significantly higher recurrence rate (P < 0.01). The 5-year overall survival of oral single primary carcinoma patients was 88.0% compared with 95% for oral multiple primary carcinomas, with no significant difference (log rank test, P = 0.54). However, the 15-year survival rate dropped to 28.1% in oral multiple primary carcinomas. The cumulative disease incidence rates of metachronous second primary carcinoma from first carcinoma at 5 years and 10 years were 3.45% and 5.36%, respectively. [Conclusion] Oral multiple primary carcinomas rarely occur in the tongue. The 5-year survival rate showed no difference between single and multiple carcinoma patients, but over longer observation, the prognosis of multiple carcinoma was poor owing to a high recurrence rate. Because of the high recurrence rate and risk of further metachronous carcinoma in oral multiple primary carcinomas, longer-term follow-up is required
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