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Usefulness of Y-shaped sheaths in CT angiography for examination of liver tumors

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World Journal of Gastroenterology 2010年第37期16卷 4704-4708页

作者： Toru Ishikawa Kazuo Higuchi tomoyuki kubota Kei-ichi Seki Terasu Honma Toshiaki Yoshida Takeo Nemoto Keiko Takeda Tomoteru Kamimura Department of Gastroenterology and Hepatology Saiseikai Niigata Second Hospital Department of Radiology Saiseikai Niigata Second Hospital

AIM: To conduct a single-stage, combined computed tomography (CT) arterial portography (CTAP) and CT arteriography (CTA) imaging operation, we used Y-shaped sheaths with 2 valves, which allowed the insertion of 2 catheters simultaneously. METHODS: Of 1254 patients who underwent abdominal angiography for transarterial embolization and/or intraarterial chemotherapy in our department from May 2002 to November 2009, 664 patients in whom Y-shaped sheaths with 2 valves were used underwent CT angiography using a combination of CTA and CTAP. The Seldinger method was used to insert a 10 cm Y-shaped short sheath with 2 valves into the femoral artery. Under radiographic guidance, a 3.2 French (Fr) catheter was placed in the celiac artery or proper hepatic artery, and a second 3.2 Fr catheter was then placed distal to the inferior pancreaticoduodenal artery of the superior mesenteric artery. CTAP was then performed followed by CTA 10 min later. Photographs were taken during the early and late phases of the ***: Insertion of 3.2 Fr catheters was not possible in 6 of 664 (0.9%) patients with strong curvature of the femoral artery and 4 of 664 (0.6%) patients with strong curvature of the abdominal aorta. In addition, performing CTAP and CTA as a single-stage combined intervention was not possible in 14 of 664 (2.1%) patients whose right hepatic artery originated from the superior mesenteric artery and in 8 of 664 (1.2%) patients whose left hepatic artery branched from the left gastric artery. There were no sheath-related complications such as those related to arterial dissection or hemostasis. CONCLUSION: Although transfers to and from the CT room were necessary for anatomically variant patients, CT angiography using the Y-shaped sheath for combined CTAP and CTA was considered useful.

关键词： Computed tomography angiography Interventional radiology Liver tumors

Shear wave velocity is a useful marker for managing nonalcoholic steatohepatitis

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World Journal of Gastroenterology 2010年第23期16卷 2918-2925页

作者： Akihiko Osaki tomoyuki kubota Takeshi Suda Masato Igarashi Keisuke Nagasaki Atsunori Tsuchiya Masahiko Yano Yasushi Tamura Masaaki Takamura Hirokazu Kawai Satoshi Yamagiwa Toru Kikuchi Minoru Nomoto Yutaka Aoyagi Department of Gastroenterology and Hepatology Graduate School of Medical and Dental SciencesNiigata University Department of Homeostatic Regulation and Development Graduate School of Medical and Dental SciencesNiigata University Department of Laboratory Medicine Niigata University Medical and Dental Hospital

AIM:To investigate whether a noninvasive measurement of tissue strain has a potential usefulness for management of nonalcoholic steatohepatitis(NASH).METHODS:In total 26 patients,23 NASHs and 3 normal controls were enrolled in this *** was staged based on Brunt *** a region of interest(ROI),a shear wave was evoked by implementing an acoustic radiation force impulse(ARFI),and the propagation velocity was quantif ***:Shear wave velocity(SWV) could be reproducibly quantified at all ROIs in all subjects except for 4 NASH cases,in which a reliable SWV value was not calculated at several *** average SWV of 1.34 ± 0.26 m/s in fibrous stage 0-1 was significantly slower than 2.20 ± 0.74 m/s and 2.90 ± 1.01 m/s in stages 3 and 4,respectively,but was not significantly different from 1.79 ± 0.78 m/s in stage *** a cutoff value was set at 1.47 m/s,receiver operating characteristic analysis showed significance to dissociate stages 3 and 4 from stage 0-1(P=0.0092) with sensitivity,specificity and area under curve of 100%,75% and 94.2%,*** addition,the correlation between SWV and hyaluronic acid was significant(P<0.0001),while a tendency toward negative correlation was observed with serum albumin(P=0.053).CONCLUSION:The clinical implementation of ARFI provides noninvasive repeated evaluations of liver stiffness at an arbitrary position,which has the potential to shed new light on NASH management.

关键词： Nonalcoholic steatohepatitis Ultrasound Liver stiffness measurement Shear wave velocity Acoustic radiation force impulse

NUMERICAL PREDICTION OF DYNAMIC PERFORMANCE OF PELTON TURBINE

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Journal of Hydrodynamics 2007年第3期19卷 356-364页

作者： kubota Takashi College of Electric Power South China University of Technology Guangzhou 510640 China

Different from the reaction turbines, the hydraulic performance of Pelton turbine is dynamic due to the unsteady flow in the rotating buckets in time and space. The dynamic energy efficiency of bucket ηεB and power efficiency of bucket ηPB within a short period can be predicted from the dynamic flow pattern of the free-surface sheet flow in the rotating bucket, whereas the dynamic discharge efficiency of bucket ηQB is defined as the resident discharge in the bucket at the respective moment. Under the operation of higher unit speed non than the optimum one, the power efficiency of bucket is deteriorated by the jet interference with the rear surface of bucket △Prear at the first stage of the dynamic performance, as well as the loss power due to the spilt flow from the cutout of bucket at the later stage of performance. Based on the dynamic performance prediction presented, the future possibility of the quantitative investigation for the negative scale effect of Pelton turbines was discussed.

关键词： dynamic energy efficiency dynamic discharge efficiency dynamic power efficiency rotating bucket Pelton turbine

Unsteady separation of jet branch by cutout of rotating Pelton bucket

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Science China(Technological Sciences) 2011年第2期54卷 302-310页

作者： kubota Takashi College of Electric Power South China University of Technology

As a part of boundaries for a free curved surface of a Pelton bucket,the cutout is indispensable to secure the smooth entrance of the unsteady inflow of water jet into the rotating *** cutout of the rotating bucket unsteadily separates a free jet into two branches in both space and time:the impinging branch landing on the relevant bucket surface,and the flow-off branch separated by the cutout toward the preceding *** order to investigate the unsteady jet separation by the cutout three-dimensionally,a semicircular free jet was discretized into 641 nodes of boundary-fitted *** position P of impinging jet branch landing on the bucket surface was acquired with the relative velocity W and the water depth D at each *** trailing edge surface of the flow-off jet branch was simultaneously computed *** complicate unsteady interaction of the bucket cutout with the branched free jets was clarified visually with the 3D view of illustrations in order to research the unsteady hydraulic performance of Pelton turbines in space and time.

关键词： cutout rotating bucket jet branch trailing edge surface of jet unsteady in space and time

Existence and Asymptotic Behavior of Radially Symmetric Solutions to a Semilinear Hyperbolic System in Odd Space Dimensions

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Chinese Annals of Mathematics,Series B 2006年第5期27卷 507-538页

作者： Hideo KUBO Kji kubota Department of Mathematics Osaka University Machikaneyama 1-1ToyonakaOsaka 560-0043Japan Department of Mathematics Hokkaido University Sapporo 060-0810Japan

This paper is concerned with a class of semilinear hyperbolic systems in odd space dimensions. Our main aim is to prove the existence of a small amplitude solution which is asymptotic to the free solution as t →-∞ in the energy norm, and to show it has a free profile as t →＋∞. Our approach is based on the work of [11]. Namely we use a weighted L^∞ norm to get suitable a priori estimates. This can be done by restricting our attention to radially symmetric solutions. Corresponding initial value problem is also considered in an analogous framework. Besides, we give an extended result of [14] for three space dimensional case in Section 5, which is prepared independently of the other parts of the paper.

关键词： Semilinear wave equations Asymptotic behavior Radially symmetric solution

Evolution of Dentary Diastema in Iguanodontian Dinosaurs

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Acta Geologica Sinica(English Edition) 2009年第1期83卷 39-45页

作者： Katsuhiro kubota Yoshitsugu KOBAYASHI Kanna Dinosaur Center Hokkaido University Museum Hokkaido University

The dentary diastema of iguanodontians has been considered to be related to its unique jaw mechanism for herbivorous adaptation. The dentary and diastema lengths of iguanodontians were measured and compared to elucidate the evolution of iguanodontian diastema. A gap in ratios between most non-hadrosaurid iguanodontians and hadrosaurids was observed, suggesting that all non- hadrosaurid iguanodontians, expect for Ouranosaurus nigeriensis and Protohadros byrdi, lack a diastema or have a short diastema, although some other taxa have been considered to have a long diastema in previous studies. In non-hadrosaurid iguanodontians, some large-sized forms, such as Iguanodon bernissartensis, Shuangmiaosaurus gilmorei, and possibly Eolambia caroljonesa, had a short diastema through ontogeny, whereas Ouranosaurus nigeriensis and Protohadros byrdi developed a long diastema convergently. The development of a long diastema of hadrosaurine hadrosaurids may be different from that of lambeosaurine hadrosaurids. Some hadrosaurines （Edmontosaurus annectens, Edmontosaurus regalis, and Saurolophus angustirostris） may have developed a long diastema in the subadult stage and showed little elongation of dentary diastema through ontogeny. Lambeosaurines （Corythosaurus casuarius and Lambeosaurus lambei） tend to have a short diastema in the embryonic and subadult stages, and an elongated diastema from the subadult to adult stages.

关键词： Cretaceous dentary diastema dinosaur iguanodontian ontogeny

Microbial characteristics in anaerobic membrane bioreactor treating domestic sewage:Effects of HRT and process performance

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Journal of Environmental Sciences 2022年第1期34卷 392-399页

作者： Jialing Ni Jiayuan Ji Yu-You Li Kengo kubota Department of Civil and Environmental Engineering Graduate School of EngineeringTohoku University6-6-06 AobaAramakiAoba-ku 980-8579SendaiJapan Department of Frontier Science for Advanced Environment Graduate School of Environmental StudiesTohoku University6-6-06 AobaAramakiAoba-ku 980-8579SendaiJapan

Two anaerobic membrane bioreactors(AnMBRs)equipped with different membrane pore size(0.4 or 0.05μm)were operated at 25℃and fed with domestic *** hydraulic retention time(HRT)of the reactors was *** microbial communities of the two AnMBRs were investigated by 16S rRNA gene amplicon sequencing to see the effects of *** predominant Archaea was an aceticlastic methanogen *** composition of hydrogenotrophic methanogens changed with the HRTs:the population of Methanobacterium was higher for longer HRTs,whereas the population of unclassified Methanoregulaceae was higher for shorter *** Anaerolineae,Bacteroidia and Clostridia bacteria were dominant in both of the reactors,with a combined relative abundance of over 55%.The relative abundance of Anaerolineae was proportional to the biogas production *** change in the population of hydrogenotrophic methanogens or Anaerolineae can be used as an indicator for process *** sum of the relative abundance of Anaerolineae and Clostridia fluctuated slightly with changes in the HRT in both AnMBRs when the reactor was stably *** co-occurrence analysis revealed the relative abundance of the operational taxonomic units belonging to Anaerolineae and Clostridia was functionally equivalent during the treatment of real domestic sewage.A principal coordination analysis revealed that the changes in the microbial community in each reactor were consistent with the change of *** addition,both the HRT and the stability of the process are important factors for maintaining microbial community structures.

关键词： Anaerobic membrane bioreactor Co-occurrence analysis Hydrogenotrophic methanogen HRT Microbial community structure Principal coordinate analysis

Optimization of causative factors using logistic regression and artificial neural network models for landslide susceptibility assessment in Ujung Loe Watershed, South Sulawesi Indonesia

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Journal of Mountain Science 2019年第2期16卷 383-401页

作者： Andang Suryana SOMA Tetsuya kubota Hideaki MIZUNO Faculty of Forestry Hasanuddin University Faculty of Agriculture Kyushu University

Landslide susceptibility maps(LSMs) play a vital role in assisting land use planning and risk mitigation. This study aims to optimize causative factors using logistic regression(LR) and an artificial neural network(ANN) to produce a LSM. The LSM is produced with 11 causative factors and then optimized using forward-stepwise LR(FSLR), ANN, and their combination(FSLR-ANN) until eight causative factors were found for each method. The ANN method produced superior validation results compared with LR. The ROC values for the training data set ranges between 0.8 and 0.9. On the other hand, validation with the percentage of landslide fall into LSM class high and very high, ANN method was higher(92.59%) than LR(82.12%). FSLR-ANN with nine causative factors gave the best validation results with respect to area under curve(AUC) values, and validation with the percentage of landslide fall into LSM class high and very high. In conclusion, ANN was found to be better than LR when producing LSMs. The best Optimization was combination of FSLR-ANN with nine causative factors and AUC success rate 0.847, predictive rate 0.844 and validation with landslide fall into high and very high class with 91.30%. It is an encouraging preliminary model towards a systematic introduction of FSLR-ANN model for optimization causative factors in landslide susceptibility assessment in the mountainous area of Ujung Loe Watershed.

关键词： Optimized causative factor Landslide, Logistic Regression Artificial neural network Indonesia

Point scoring system to rank traffic calming projects

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Journal of Traffic and Transportation Engineering(English Edition) 2016年第4期3卷 324-335页

作者： Farzana Rahman Hisashi kubota Department of Civil Engineering University of Asia Pacific Graduate School of Science and Engineering Department of Civil & Environmental EngineeringSaitama University

The installation of calming measures on a road network is systematically planned way in general to reduce driving speeds, but also reduces the volume of through traffic on local and residential streets. When the demands of traffic calming exceed city resources, there is a need to prioritize or rank them. Asian countries, like lapan, Korea, Bangladesh and etc., do not have a ptioritization system to apply in such cases. The objective of this research is to develop a point ranking system to prioritize traffic calming projects. Firstly paired comparison method was employed to obtain residents＇ opinions about the streets severity and needs of traffic calming treatment. A binary logistic regression model was developed to identify the factors of selecting streets for traffic calming. This model also explored the weight of variables during developing the point ranking system. The weights used in the point ranking system include vehicle speed, pedestrian generation, sidewalk condition and hourly vehicle volume per width （m） of street. Results suggest that the severity of street largely depends on the absence of sidewalks, which has a weight of 45%, and high hourly vehicle volume of traffic per width （m） of street, which has a weight of 38%. These outcomes are significant to develop the state of traffic safety in Japan and other Asian countries.

关键词： Traffic calmingPrioritizePaired comparison methodPreferenceSafety