212 research outputs found

    Fourier coefficient of parameterized quantum circuits and barren plateau problem

    Full text link
    We show the relationship between the Fourier coefficients and the barren plateau problem emerging in parameterized quantum circuits. In particular, the sum of squares of the Fourier coefficients is exponentially restricted concerning the qubits under the barren plateau condition. Throughout theory and numerical experiments, we introduce that this property leads to the vanishing of a probability and an expectation formed by parameterized quantum circuits. The traditional barren plateau problem requires the variance of gradient, whereas our idea does not explicitly need a statistic. Therefore, it is not required to specify the kind of initial probability distribution.Comment: 5 pages, 4 figure

    A computer-aided temporal and dynamic subtraction technique of the liver for detection of small hepatocellular carcinomas on abdominal CT images

    Get PDF
    金沢大学大学院医学系研究科量子医療技術学It is often difficult for radiologists to identify small hepatocellular carcinomas (HCCs) due to insufficient contrast enhancement. Therefore, we have developed a new computer-aided temporal and dynamic subtraction technique to enhance small HCCs, after automatically selecting images set at the same anatomical position from the present (non-enhanced and arterial-phase CT images) and previous images. The present study was performed with CT images from 14 subjects. First, we used template-matching based on similarities in liver shape between the present (non-enhanced and arterial-phase CT images) and previous arterial-phase CT images at the same position. Temporal subtraction images were then obtained by subtraction of the previous image from the present image taken at the same position of the liver. Dynamic subtraction images were also obtained by subtraction of non-enhanced CT images from arterial-phase CT images taken at the same position of the liver. Twenty-one of 22 nodules (95.5%) with contrast enhancement were visualized in temporal and dynamic subtraction images. Compared with present arterial-phase CT images, increases of 150% and 140% in nodule-to-liver contrast were observed on dynamic and temporal subtraction images, respectively. These subtraction images may be useful as reference images in the detection of small moderately differentiated HCCs. © 2006 IOP Publishing Ltd

    Radioanatomical study of the bronchovascular anomalies of the middle and lower lobes of the right lung using multidetector computed tomography

    Get PDF
    石川県済生会金沢病院放射線部金沢大学医薬保健研究域保健学系Objective:: Preoperative evaluation of bronchovascular structures is useful for prevention of accidents in pulmonary lobectomy. The purpose of this study was to examine the frequency and multidetector computed tomographic (CT) appearances of bronchovascular anomalies between the right middle and lower lobes. Methods:: A total of 1116 consecutive chest CT examinations were analyzed in the present study. On display, the bronchovascular anomalies between the right middle and lower lobes were searched. When anomalous structures were observed, 3-dimensional images were reconstructed. Results:: Sixty-seven cases (6.0%) with anomalous findings were observed. In 20 cases (1.79%), the right middle lobe bronchus and artery supplied the lower lobe, whereas the lower lobe artery supplied the right middle lobe in 46 cases (4.12%). In 1 case (0.09%), the 2 patterns previously mentioned were observed concomitantly. Conclusions:: Anomalous bronchovascular structures between the right middle and lower lobes were identified by a multidetector CT with an incidence of 6.0%. Knowledge of the frequency and CT features is useful for preoperative CT evaluation. © 2009 Lippincott Williams & Wilkins

    Lesões pancreáticas em Doença de Chagas aguda experimental

    Get PDF
    BACKGROUND: Chagas' disease is an endemic tropical affliction found from southern United States to Argentina. The acute phase of this disease is difficult to study in man because the symptoms are non-specific and most cases require no medical assistance. Experimental models have been developed for sequential studies, and intense parasitism in all organs and tissues, including the pancreas, have been detected in the acute phase. PURPOSE: To evaluate the involvement of the pancreas in acute experimental Chagas' disease in a mouse model by histopathological characterization. CASUISTIC AND METHODS: Ten BALBc mice, about 20 g, injected i.p. with 100 000 forms of the Y strain of Trypanosoma cruzi were used. The animals were sacrificed after 14 days of infection. Fragments of pancreas were processed by conventional paraffin embedding and hematoxylin-eosin staining. RESULTS: Ruptured pseudocysts and release of parasites to the extracellular medium caused by necrosis of acinar and duct cells and foci of fat were the most striking histopathological features of acute Chagasic pancreatitis. CONCLUSION: Parasitism is the main cause of acute pancreatitis in Chagas' disease.INTRODUÇÃO: A Doença de Chagas é uma endemia tropical encontrada desde o sul dos Estados Unidos até a Argentina. Os estudos de fase aguda da doença são difíceis de serem realizados em seres humanos porque os sintomas são inespecíficos e a maioria dos casos não requer socorro médico. Em modelos experimentais desenvolvidos a doença aguda aparece com intenso parasitismo em todos os órgãos e tecidos. OBJETIVO: Caracterizar histopatologicamente o envolvimento pancreático na Doença de Chagas aguda experimental. CASUÍSTICA E MÉTODOS: Com esta finalidade utilizamos animais inoculados intraperitonialmente com 100.000 formas de cepa Y de Trypanosoma cruzi. Os animais foram sacrificados após 14 dias de infecção e os fragmentos colhidos foram processados em parafina e corados pela H&E. RESULTADOS: As características histopatológicas mais importantes da pancreatite aguda na Doença de Chagas experimental são: pseudocistos intensamente parasitados, íntegros ou rompidos, parasitas no espaço extracelular, necrose de células acinares e ductais, além de focos de esteatonecrose. CONCLUSÃO: O parasitismo dos tecidos é o principal mecanismo patogenético da pancreatite aguda na Doença de Chagas

    The Subaru FMOS Galaxy Redshift Survey (FastSound). II. The Emission Line Catalog and Properties of Emission Line Galaxies

    Full text link
    We present basic properties of \sim3,300 emission line galaxies detected by the FastSound survey, which are mostly Hα\alpha emitters at zz \sim 1.2-1.5 in the total area of about 20 deg2^2, with the Hα\alpha flux sensitivity limit of 1.6×1016erg cm2s1\sim 1.6 \times 10^{-16} \rm erg \ cm^{-2} s^{-1} at 4.5 sigma. This paper presents the catalogs of the FastSound emission lines and galaxies, which will be open to the public in the near future. We also present basic properties of typical FastSound Hα\alpha emitters, which have Hα\alpha luminosities of 1041.810^{41.8}-1043.310^{43.3} erg/s, SFRs of 20--500 MM_\odot/yr, and stellar masses of 1010.010^{10.0}--1011.310^{11.3} MM_\odot. The 3D distribution maps for the four fields of CFHTLS W1--4 are presented, clearly showing large scale clustering of galaxies at the scale of \sim 100--600 comoving Mpc. Based on 1,105 galaxies with detections of multiple emission lines, we estimate that contamination of non-Hα\alpha lines is about 4% in the single-line emission galaxies, which are mostly [OIII]λ\lambda5007. This contamination fraction is also confirmed by the stacked spectrum of all the FastSound spectra, in which Hα\alpha, [NII]λλ\lambda \lambda6548,6583, [SII]λλ\lambda \lambda6717, 6731, and [OI]λλ\lambda \lambda6300,6364 are seen.Comment: 17 pages, 15 figures, accepted for publication in PAS
    corecore