322 research outputs found

    Note on massless bosonic states in two-dimensional field theories

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    In a wide class of GL×GRG_L\times G_R invariant two-dimensional super-renormalizable field theories, the parity-odd part of the two-point function of global currents is completely determined by a fermion one-loop diagram. For any non-trivial fermion content, the two-point function possesses a massless pole which corresponds to massless bosonic physical states. As an application, we show that two-dimensional N=(2,2)\mathcal{N}=(2,2) supersymmetric gauge theory without a superpotential possesses U(1)L×U(1)RU(1)_L\times U(1)_R symmetry and contains one massless bosonic state per fixed spatial momentum. The N=(4,4)\mathcal{N}=(4,4) supersymmetric pure Yang-Mills theory possesses SU(2)L×SU(2)RSU(2)_L\times SU(2)_R symmetry, and there exist at least three massless bosonic states.Comment: 17pages, 4 figures, uses PTPTeX.cls and feynMF, added an appendi

    Failure pressure of straight pipe with wall-thinning under

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    The failure pressure of pipe with wall-thinning was investigated by using three-dimensional elastic-plastic finite element analyses (FEA). With careful modeling of the pipe and flaw geometry in addition to a proper stress-strain relation of the material, FEA could estimate the precise burst pressure obtained by the tests. FEA was conducted by assuming three kinds of materials: line pipe steel, carbon steel, and stainless steel. The failure pressure obtained using line pipe steel was the lowest under the same flaw size condition, when the failure pressure was normalized by the value of unflawed pipe defined using the flow stress. On the other hand, when the failure pressure was normalized by the results of FEA obtained for unflawed pipe under various flaw and pipe configurations, the failure pressures of carbon steel and line pipe steel were almost the same and lower than that of stainless steel. This suggests that the existing assessment criteria developed for line pipe steel are applicable to making a conservative assessment of carbon steel and stainless steel

    Structure Characterization of Fe-B Amorphous Alloys by a Laboratory EXAFS Spectrometer

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    The local atomic arrangement for Fe-B amorphous alloys in both as-prepared and mechanically deformed states was investigated by a laboratory EXAFS spectrometer. It was found that the nearest neigh-bour distance changed drastically at 16 to 18 at% of B atom concentration and that the mechanical deformation (cold rolling and tension yielded the non-uniform displacement of Fe atoms in Fe-B amorphous alloys, keeping the Fe-B correlation unchanged

    ピーマン(Capsicum annuum L.)に導入されたL2抵抗性遺伝子を打破する日本産トバモウイルス系統ペッパーマイルドモットルウイルス(PMMoV)の疫学的調査

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    To understand the epidemiological aspects of tobamovirus infecting the L resistance genotypes of green pepper, fifteen isolates were collected from geographically different fields and were chracterized by their biological properties. All isolates infected L1 and L2 plants systemically, but were localized in L3 and L4 plants. The symptomatology on several test plants and the reactivity to an antiserum showed that they were identical to that of a Japanese strain of pepper mild mottle virus (PMMoV-J). The viral infection was also confirmed by a reverse transcription and polymerase chain reaction (RT-PCR) with oligonucleotide primers that amplity the coat protein gene of PMMoV-RNA. On the other hand, the RT-PCR allowed us to detect PMMoV in seeds of some commercial cultivars of green pepper. Viruses isolated from the seeds could infect L2 plants systemically. Further analysis of the nucleotide sequence of the predicted coat protein gene revealed that the isolates from the commercial seeds were identical to that of PMMoV-J. These results indicated that the L2 resistance-breaking tobamovirus has prevailed in fields of green pepper in Japan. and that infected seeds may be one of the initial sources of the viral infection

    Quantitative and qualitative evaluation of sequential PET/MRI using a newly developed mobile PET system for brain imaging

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    [Purpose]To evaluate the clinical feasibility of a newly developed mobile PET system with MR-compatibility (flexible PET; fxPET), compared with conventional PET (cPET)/CT for brain imaging.[Methods]Twenty-one patients underwent cPET/CT with subsequent fxPET/MRI using 18F-FDG. As qualitative evaluation, we visually rated image quality of MR and PET images using a four-point scoring system. We evaluated overall image quality for MR, while we evaluated overall image quality, sharpness and lesion contrast. As quantitative evaluation, we compared registration accuracy between two modalities [(fxPET and MRI) and (cPET and CT)] measuring spatial coordinates. We also examined the accuracy of regional 18F-FDG uptake.[Results]All acquired images were of diagnostic quality and the number of detected lesions did not differ significantly between fxPET/MR and cPET/CT. Mean misregistration was significantly larger with fxPET/MRI than with cPET/CT. SUVmax and SUVmean for fxPET and cPET showed high correlations in the lesions (R = 0.84, 0.79; P < 0.001, P = 0.002, respectively). In normal structures, we also showed high correlations of SUVmax (R = 0.85, 0.87; P < 0.001, P < 0.001, respectively) and SUVmean (R = 0.83, 0.87; P < 0.001, P < 0.001, respectively) in bilateral caudate nuclei and a moderate correlation of SUVmax (R = 0.65) and SUVmean (R = 0.63) in vermis.[Conclusions]The fxPET/MRI system showed image quality within the diagnostic range, registration accuracy below 3 mm and regional 18F-FDG uptake highly correlated with that of cPET/CT

    An OFDM Receiver with Frequency Domain Diversity Combined Impulsive Noise Canceller for Underwater Network

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    In order to explore marine natural resources using remote robotic sensor or to enable rapid information exchange between ROV (remotely operated vehicles), AUV (autonomous underwater vehicle), divers, and ships, ultrasonic underwater communication systems are used. However, if the communication system is applied to rich living creature marine environment such as shallow sea, it suffers from generated Impulsive Noise so-called Shrimp Noise, which is randomly generated in time domain and seriously degrades communication performance in underwater acoustic network. With the purpose of supporting high performance underwater communication, a robust digital communication method for Impulsive Noise environments is necessary. In this paper, we propose OFDM ultrasonic communication system with diversity receiver. The main feature of the receiver is a newly proposed Frequency Domain Diversity Combined Impulsive Noise Canceller. The OFDM receiver utilizes 20–28 KHz ultrasonic channel and subcarrier spacing of 46.875 Hz (MODE3) and 93.750 Hz (MODE2) OFDM modulations. In addition, the paper shows Impulsive Noise distribution data measured at a fishing port in Okinawa and at a barge in Shizuoka prefectures and then proposed diversity OFDM transceivers architecture and experimental results are described. By the proposed Impulsive Noise Canceller, frame bit error rate has been decreased by 20–30%

    Evaluation of patients who underwent percutaneous transhepatic portal vein embolisation by Tc-99m GSA scintigraphy

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    Purpose: To analyse the correlation between the fold change in residual liver volume (RLV) and residual liver uptake at 15 (RLU15) before and after percutaneous transhepatic portal vein embolisation (PTPE). Material and methods: Between August 2010 and December 2016, 20 patients who underwent PTPE were retrospectively selected. Before and three weeks after PTPE, contrast-enhanced computed tomography (CECT) and Tc-99m GSA scintigraphy were performed to analyse the fold changes in RLV and RLU15, respectively, as well as their correlation. Results: After PTPE, a significant increase was observed in the RLV (before: 464 ± 99 ml; after: 573 ± 118 ml, p = 0.004) and the RLU15 (before: 11.0 ± 2.9%; after: 17.7 ± 3.8%, p = 5 × 10-7). The fold increase of RLV and RLU15 in all patients was 1.25 ± 0.15 and 1.66 ± 0.33, respectively. No significant correlation was observed in the fold increase in both RLV and RLU15 (r = 0.14, p = 0.66). In patients no. 3 and 9, who were outliers, the increase in RLV was minimal and RLU15 increased greatly, and these 2 patients underwent radical hepatectomy after PTPE. Conclusions: No correlation was observed between the fold increase in RLV and RLU15 before and after PTPE. In order to accurately evaluate the residual liver function, it should be considered necessary to evaluate not only by morphological CECT volumetry, but also by functional outcome of Tc-99m GSA scintigraphy. Residual liver volume may not necessarily reflect RLF. It may be possible to improve the radical resection rate by detecting the potential increase of RLF with RLU15 of Tc-99m GSA scintigraphy

    CHAC1 overexpression in human gastric parietal cells with Helicobacter pylori infection in the secretory canaliculi

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    Background Cation transport regulator 1 (CHAC1), a newly discovered enzyme that degrades glutathione, is induced in Helicobacter pylori (H. pylori)‐infected gastric epithelial cells in culture. The CHAC1‐induced decrease in glutathione leads to an accumulation of reactive oxygen species and somatic mutations in TP53. We evaluated the possible correlation between H. pylori infection and CHAC1 expression in human gastric mucosa. Materials and Methods Both fresh‐frozen and formalin‐fixed paraffin‐embedded tissue samples of gastric mucosa with or without H. pylori infection were obtained from 41 esophageal cancer patients that underwent esophago‐gastrectomy. Fresh samples were used for real‐time polymerase chain reaction for H. pylori DNA and CHAC1 mRNA, and formalin‐fixed samples were used for immunohistochemistry with anti‐CHAC1 and anti‐H. pylori monoclonal antibodies. Double‐enzyme or fluorescence immunohistochemistry and immuno‐electron microscopy were used for further analysis. Results Significant CHAC1 overexpression was detected in H. pylori‐infected parietal cells that expressed the human proton pump/H,K‐ATPase α subunit, whereas a constitutively low level of CHAC1 mRNA expression was observed in the other samples regardless of the H. pylori infection status, reflecting the weak CHAC1 expression detected by immunohistochemistry in the fundic‐gland areas. Immuno‐electron microscopy revealed intact H. pylori cells in the secretory canaliculi of infected parietal cells. Some parietal cells exhibited positive nuclear signals for Ki67 in the neck zone of the gastric fundic‐gland mucosa with H. pylori infection. Conclusion Cation transport regulator 1 overexpression in H. pylori‐infected parietal cells may cause the H. pylori‐induced somatic mutations that contribute to the development of gastric cancer.This work was supported by the Japan Society for the Promotion of Science KAKENHI (16K19077), and by the Practical Research for Innovative Cancer Control from Japan Agency for Medical Research and development, AMED

    A micro ultrasonic motor using a micro-machined cylindrical bulk PZT transducer

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    In this paper, a micro ultrasonic motor using a micro-machined bulk piezoelectric transducer is introduced. The cylindrical shaped bulk piezoelectric transducer, a diameter of 0.8 mm and a height of 2.2 mm, was developed as stator transducer for traveling wave type ultrasonic motor. The transducer was made of lead zirconate titanate (PZT) bulk ceramics, and formed by micro machining, Ni plating and laser beam cutting process. Using this stator transducer, we have fabricated a cylindrical micro ultrasonic motor, a diameter of 2.0 mm and a height of 5.9 mm. We have also evaluated some characteristics and succeeded in driving the micro ultrasonic motor.</p
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