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Concentration-Dependent Solar Thermochemical CO_(2)/H_(2)O Splitting Performance by Vanadia-Ceria Multiphase Metal Oxide Systems

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Research 2020年第1期2020卷 522-533页

作者： Asim Riaz Muhammad Umair Ali T.Gabriel Enge takuya Tsuzuki Adrian Lowe Wojciech Lipinski Research School of Electrical Energy and Materials EngineeringThe Australian National UniversityCanberra ACT 2601Australia Department of Materials Science and Engineering College of EngineeringPeking UniversityBeijing 100871China Research School of Earth Sciences The Australian National UniversityCanberra ACT 2601Australia

The effects of V and Ce concentrations(each varying in the 0-100%range)in vanadia-ceria multiphase systems are investigated for synthesis gas production via thermochemical redox cycles of CO_(2) and H_(2)O splitting coupled to methane partial oxidation *** oxidation of prepared oxygen carriers is performed by separate and sequential CO_(2) and H_(2)O splitting *** and chemical analyses of the mixed-metal oxides revealed important information about the Ce and V interactions affecting their crystal phases and redox *** CeO_(2) and pure V_(2)O_(5) are found to offer the lowest and highest oxygen exchange capacities and syngas production performance,*** mixed-oxide systems provide a balanced performance:their oxygen exchange capacity is up to 5 times higher than that of pure CeO_(2) while decreasing the extent of methane *** addition of 25%V to CeO_(2) results in an optimum mixture of CeO_(2) and CeVO4 for enhanced CO_(2) and H_(2)O *** higher V concentrations,cyclic carbide formation and oxidation result in a syngas yield higher than that for pure CeO_(2).

关键词： pure methane splitting

Anaplastic carcinoma associated with a mucinous cystic neoplasm of the pancreas during pregnancy:Report of a case and a review of the literature

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World Journal of Gastroenterology 2008年第1期14卷 132-135页

作者： Kenichi Hakamada takuya Miura Akitoshi Kimura Masaki Nara Yoshikazu Toyoki Shunij Narumi Mutsuo Sasak Department of Gastroenterological Surgery Hirosaki University Graduate School of Medicine Hirosaki 036-8562 Japan

Oncogenesis of anaplastic carcinoma of the pancreas is a subject of controversy, because it shows sarcomatous nature with extremely poor prognosis. We herein report an unusual case of anaplastic carcinoma occurring with a recurrent mucinous cystic neoplasm in a 38-year-old female. A 10-cm retroperitoneal cystic mass was pointed out in the first pregnancy and a probable diagnosis of mucinous cystic neoplasm was made in October 2000. She refused surgery first and delivered her baby uneventfully. During her second pregnancy in 2002, however, she presented hematemesis and underwent urgent distal pancreatectomy, splenectomy and partial resection of the gastric wall where the tumor perforated. A diagnosis of borderline-type mucinous cystic neoplasm with ovarian-like stroma was made. Nine months later, CT visualized a recurrent cystic tumor near the pancreatic stump, which was subsequently resected. Pathology revealed that the tumor was composed of two different components of borderline-type mucinous cystic neoplasm and anaplastic carcinoma. The latter was intensely positive for vimentin, CD68, p53 and focally for cytokeratin, suggesting both sarcomatous and carcinomatous differentiation. She survived four years after the second surgery without tumor recurrence. Although the origin of anaplastic carcinoma has not been determined yet, it should be remembered that anaplastic carcinoma can occur in association with mucinous cystic neoplasm of more benign histology.

关键词： Mucinous cystic neoplasm Anaplastic carcinoma Pancreatic tumor Ovarian-like stroma Pregnancy

Primary rhegmatogenous retinal detachment:evaluation of a minimally restricted face-down positioning after pars plana vitrectomy and gas tamponade

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International Journal of Ophthalmology(English edition) 2021年第6期14卷 936-939页

作者： Kiichiro Kusaba Kotaro Tsuboi Tsuneaki Handa Yukihiko Shiraki takuya Kataoka Motohiro Kmaei Department of Ophthalmology Aichi Medical UniversityNagakute-cityAichi 480-1195Japan

AIM:To evaluate the safety and efficacy of a minimally restricted face-down postoperative positioning following pars plana vitrectomy(PPV)with gas tamponade for primary rhegmatogenous retinal detachment(RRD).METHODS:Patients with primary RRD treated with PPV and gas tamponade and followed up for at least 6 mo were selected for the *** phakic eyes underwent simultaneous cataract *** patients were required to be in a postoperative position that prevented downward flow of retinal *** with macular detachment were positioned face-down for only a couple of *** patients were assessed for preoperative and postoperative best-corrected visual acuity(BCVA),anatomical retinal reattachment rate,and postoperative ***:In total,40 eyes of 39 patients with primary RRD were included in the study.A single tear was present in 30 eyes(75.0%),multiple retinal tears were present in nine eyes(22.5%),and oral dialysis was present in one eye(2.5%).The anatomical success rate was 90.0%(36 cases)after the primary surgery,and the final anatomical success rate was 100%.The BCVA improved significantly(P<0.001)from 0.75 logarithm angle of resolution(log MAR)preoperatively to 0.12 log MAR at the final *** complications included intraocular pressure elevation(≥25 mm Hg)in 11 patients(27.5%),fibrin formation in two patients(5.0%),pupillary capture of the intraocular lens in two patients(5.0%),and posterior synechia in one patient(2.5%).CONCLUSION:A minimally restricted face-down and flexible postoperative positioning after PPV and gas tamponade for primary RRD is effective and safe.

关键词： retinal detachment vitrectomy flexible postoperative positioning

A Case of Muscle Contraction-Induced Ischemic Limb Hyperemia in a Patient with Peripheral Arterial Disease during Incremental Repeat Isometric Knee Extensor Workloads

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World Journal of Cardiovascular Diseases 2020年第12期10卷 796-808页

作者： takuya Osada Cardiac Rehabilitation Center Tokyo Medical University Hospital Tokyo Japan Rehabilitation Center Tokyo Medical University Hospital Tokyo Japan

Background: To determine whether muscle contraction-induced leg blood flow (LBF) during exercise may be altered in a patient with an ischemic limb due to peripheral arterial disease (PAD) compared with the non-PAD limb. Case Presentation: A 66-year-old male patient with intermittent claudication due to PAD in the right leg (ankle brachial pressure index, 0.69) showed complete obstruction in both common iliac arteries including internal/external segments with collaterals above the femoral artery and popliteal artery with collaterals, and in the healthy left non-PAD-leg (1.06). He attempted unilateral repeat isometric knee extensions at a target contraction rhythm with each leg at incremental contraction intensities (5%, 10%, and 30% of maximum voluntary contraction [MVC] for 3 min at each intensity). Blood velocity/flow (Doppler ultrasound) in the femoral artery, blood pressure, and leg vascular conductance (LVC) were measured. Isometric thigh MVC strength pre-exercise was similar between the PAD-leg (48.0 kg) and non-PAD-leg (48.7 kg). Pre-exercise LBF (ml/min) was also similar between the PAD-leg (316) and non-PAD-leg (327). Blood pressure increases were similar during exercise. Average exercising LBF in ml/min in the last 1 min at each intensity was higher in the PAD-leg than the non-PAD-leg: 1087 vs. 471 at 5%, 2097 vs. 712 at 10%, and 2656 vs. 1517 at 30% MVC with a close positive linear relationship between LBF and %MVC in the non-PAD-leg (r = 0.999, P Conclusion: Knee extensor exercising LBF in the femoral artery was dissimilar between the PAD-leg and non-PAD-leg at the same exercise intensity, even though pre-exercising LBF was the same. Further research on the time-course

关键词： Leg Blood Flow Peripheral Arterial Disease Collaterals Flow Repeat Isometric Knee Extensor Exercise Doppler Ultrasound

Numerical Simulation of a Domain-Tessellation Pattern on a Spherical Surface Using a Phase Field Model

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Open Journal of Modelling and Simulation 2016年第2期4卷 24-33页

作者： takuya Uehara Department of Mechanical Systems Engineering Yamagata University Yonezawa Japan

A numerical simulation scheme is proposed to analyze domain tessellation and pattern formation on a spherical surface using the phase-field method. A multi-phase-field model is adopted to represent domain growth, and the finite-difference method (FDM) is used for numerical integration. The lattice points for the FDM are distributed regularly on a spherical surface so that a mostly regular triangular domain division is realized. First, a conventional diffusion process is simulated using this lattice to confirm its validity. The multi-phase-field equation is then applied, and pattern formation processes under various initial conditions are simulated. Unlike pattern formation on a flat plane, where the regular hexagonal domains are always stable, certain different patterns are generated. Specifically, characteristic stable patterns are obtained when the number of domains, n, is 6, 8, or 12;for instance, a regular pentagonal domain division pattern is generated for n = 12, which corresponds to a regular dodecahedron.

关键词： Pattern Formation Domain Tessellation Computer Simulation Phase Field Method

Simulation of Polyhedral Crystal Growth Based on the Estimated Surface Energy of Crystallographic Planes

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Materials Sciences and Applications 2021年第11期12卷 519-533页

作者： takuya Uehara Department of Mechanical Systems Engineering Yamagata University Yonezawa Japan

Polyhedral shapes can be found in crystalline materials ranging from macroscopic natural mineral solids to microscopic or nanoscopic particles. These shapes originate from the crystallographic properties of the constituting material, and the outer shape depends on several unique habit planes. In this study, polyhedral crystal growth was simulated considering the surface energy and crystallographic characteristics. A series of polyhedrons, including cube, truncated hexahedron, cuboctahedron, truncated octahedron, and regular octahedron, was targeted. First, the polyhedron’s static surface energy and dynamic energy variation during crystal growth were computed. Then, the crystal-growth process was simulated based on the energy minimization policy. Interestingly, when the simulation began with truncated hexahedral nucleus, the shape changed to a cuboctahedron;however, a certain type of truncated octahedron was obtained when starting with different types of truncated octahedrons. In addition, once converged cuboctahedron abruptly changed the shape to a truncated octahedron as the crystal became larger. These results were supported by the static and dynamic energy curves. Furthermore, the method was applied to different materials by assuming virtual parameters, yielding various morphologies.

关键词： Polyhedron Crystalline Material Morphology Nanoparticle Energy Minimization Crystal-Growth Simulation

Simulation of Crack Pattern Formation Due to Shrinkage in a Drying Material

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Open Journal of Modelling and Simulation 2023年第1期11卷 1-13页

作者： takuya Uehara Department of Mechanical Systems Engineering Yamagata University Yonezawa Japan

Crack patterns observed in nature have attracted the interest of researchers in various fields, and the mechanism of the pattern formation has been investigated. However, the phenomenon is very complicated, and many factors affect the process. Therefore, we are motivated to construct a general simulation code with a simple algorithm. In this study, crack pattern formation due to shrinkage caused by the drying of a wet material was simulated. The process was simplified as follows: tensile force is generated in the model, and a crack is generated when the tension exceeds a critical value. The tensile forces in the x and y directions are independently evaluated. A crack propagates perpendicular to the tension until it reaches another crack or a boundary. Based on this modeling, simulations with a two-dimensional square domain were performed. Consequently, a cross-divided pattern was generated. Assuming zigzag crack propagation, more realistic patterns were obtained. The effects of the boundary and domain size were also considered, and various characteristic patterns were obtained. Furthermore, the orientation dependency was simulated, and 45˚ declined patterns and rectangularly divided patterns were generated. The model presented in this study is very simplified and is expected to be applicable to various objects.

关键词： Desiccation Crack Tensile Force Crack Initiation Crack Propagation Pattern Formation Computer Simulation

Biochemically curative surgery for gastrinoma in multiple endocrine neoplasia type 1 patients

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World Journal of Gastroenterology 2011年第10期17卷 1343-1353页

作者： Masayuki Imamura Izumi Komoto Shuichi Ota takuya Hiratsuka Shinji Kosugi Ryuichiro Doi Masaaki Awane Naoya Inoue Department of Surgery Kansa Electric Power Company Hospital Departments of Surgery and Pathology Saiseikai Noe Hospital Medical Gene Research Center Graduate School of Medicine Kyoto University Department of Surgery Graduate School of MedicineKyoto University

AIM： To search for the optimal surgery for gastrinoma and duodenopancreatic neuroendocrine tumors in patients with multiple endocrine neoplasia type 1. METHODS： Sixteen patients with genetically confirmed multiple endocrine neoplasia type 1 （MEN 1） and Zollinger-Ellison syndrome （ZES） underwent resection of both gastrinomas and duodenopancreatic neuroendocrine tumors （NETs） between 1991 and 2009. For localization of gastrinoma, selective arterial secretagogue injection test （SASI test） with secretin or calcium solution was performed as well as somatostatin receptor scintigraphy （SRS） and other imaging methods such as computed tomography （CT） or magnetic resonance imaging （MRI）. The modus of surgery for gastrinoma has been changed over time, searching for the optimal surgery： pancreaticoduodenectomy （PD） was first performed guided by localization with the SAST test, then local resection of duodenal gastrinomas with dissection of regional lymph nodes （LR）, and recently pancreas-preserving total duodenectomy （PPTD） has been performed for multiple duodenal gastrinomas. RESULTS： Among various types of preoperative localizing methods for gastrinoma, the SASI test was the most useful method. Imaging methods such as SRS or CT made it essentially impossible to differentiate functioning gastrinoma among various kinds of NETs. However, recent imaging methods including SRS or CT were useful for detecting both distant metastases and ectopic NETs; therefore they are indispensable for staging of NETs. Biochemical cure of gastrinoma was achieved in 14 of 16 patients （87.5%）; that is, 100% in 3 patients who underwent PD, 100% in 6 patients who underwent LR （although in 2 patients （33.3%） second LR was performed for recurrence of duodenal gastri- noma）, and 71.4% in 7 patients who underwent PPTD. Pancreatic NETs more than 1 cm in diameter were resected either by distal pancreatectomy or enucleations, and no hepatic metastases have developed postoperatively. Pathological study of the

关键词： Gastrinoma Duodenopancreatic neuroendocrine tumors Multiple endocrine neoplasia type 1 Selective arterial secretagogue injection test 5omatostatin receptor scintigraphy Pancreas-preserving total duode- nectomy Pancreaticoduodenectomy

Histopathological and genetic differences between polypoid and non-polypoid submucosal colorectal carcinoma

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World Journal of Gastroenterology 2007年第14期13卷 2048-2052页

作者： Ichiro Hirata Fang-Yu Wang Mitsuyuki Murano takuya Inoue Ken Toshina Takashi Nishikawa Kentaro Maemura Department of Gastroenterology Fujita Health University Japan Department of Gastroenterology Jinling Hospital Nanjing University School of Medicine Nanjing 210000 Jiangshu Province China Second Department of Internal medicine Osaka medical College Japan Department of Anatomy Osaka Medical College Japan

AIM： To investigate the histopathological and geneticdifferences between polypoid growth （PG） and nonpolypoid growth （NPG） submucosal invasive colorectal carcinoma （CRC）.METHODS： A total of 96 cases of submucosal CRC were divided into two groups according to their growth type;60 cases of PG and 36 cases of NPG. The size, histological degree of dysplasia, depth of submucosal invasion and lymph node metastasis were compared between the two groups. Furthermore, expression of p53 was detected by immunohistochemical staining, and K-ras gene mutation was examined by polymerase chain reaction based single-strand conformation polymorphism （SSCP）.RESULTS： The average size of the lesions in the NPG group was significantly smaller than those in the PG group （7.5 mm vs 13.8 mm, P 〈 0.001）. The histological degree of dysplasia tended to be more severe in NPG group, while the incidence of submucosal massive invasion and the lymph node metastasis were both significantly higher in the NPG type than in the PG group （64.3% vs 43.3%, P = 0.004; 43% vs 7%, P =0.008, respectively）. In addition, K-ras gene mutations were detected in 67% of lesions in the PG group, but none in the NPG group, while no difference in p53immunohistochemical expression was found between the two groups.CONCLUSION： Compared with PG submucosal CRC,NPG type demonstrates more frequent submucosal massive invasion, more lymph node metastasis and a higher degree dysplasia. Genetically, NPG type shows much less frequent K-ras mutation.

关键词： Colorectal cancer Early/submucosal Polypoidgrowth Non-polypoid growth Histogenesis K-ras gene p53