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Quasi-periodic orbits of small solar sails with time-varying attitude around Earth–Moon libration points

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Astrodynamics 2024年第1期8卷 161-174页

作者： toshihiro Chujo Department of Mechanical Engineering School of EngineeringTokyo Institute of TechnologyTokyo152-8550Japan

This paper proposes new quasi-periodic orbits around Earth–Moon collinear libration points using solar *** including the time-varying sail orientation in the linearized equations of motion for the circular restricted three-body problem(CR3BP),four types of quasi-periodic orbits(two types around L1 and two types around L2)were *** them,one type of orbit around L2 realizes a considerably small geometry variation while ensuring visibility from the Earth if(and only if)the sail acceleration due to solar radiation pressure is approximately of a certain magnitude,which is much smaller than that assumed in several previous *** means that only small solar sails can remain in the vicinity of L2 for a long time without propellant *** orbits designed in the linearized CR3BP can be translated into nonlinear CR3BP and high-fidelity ephemeris models without losing geometrical *** this study,new quasi-periodic orbits are formulated,and their characteristics are ***,their extendibility to higher-fidelity dynamic models was verified using numerical examples.

关键词： solar sail libration point orbit Earth-Moon system circular restricted three-body problem(CR3BP)

Optimization of body configuration and joint-driven attitude stabilization for transformable spacecraft under solar radiation pressure

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Astrodynamics 2024年第1期8卷 47-60页

作者： Yuki Kubo toshihiro Chujo Institute of Space and Astronautical Science Japan Aerospace Exploration AgencyKanagawa252-5210Japan Department of Mechanical Engineering Tokyo Institute of TechnologyTokyo152-8550Japan

The solar sail is one of the most promising space exploration systems due to its theoretically infinite specific impulse achieved through solar radiation pressure(SRP).Recently,researchers have proposed“transformable spacecraft”capable of actively reconfiguring their body configurations using actuatable *** spacecraft,if used similarly to solar sails,are expected to significantly enhance orbit and attitude control capabilities owing to their high redundancy in control degrees of ***,controlling them becomes challenging due to their large number of inputs,leading previous researchers to impose strong constraints to limit their potential control *** study focuses on novel attitude control techniques for transformable spacecraft under *** developed two methods,namely,joint angle optimization to obtain arbitrary SRP force and torque,and momentum damping control driven by joint angle *** proposed methods are formulated in a general manner and can be applied to any transformable spacecraft comprising front faces that can predominantly receive the SRP on each *** validity of our proposed method is confirmed through numerical *** study contributes to making most of the high control redundancy of transformable spacecraft without the need for expendable propellants,thus significantly enhancing the orbit and attitude control capabilities.

关键词： solar sail transformable spacecraft attitude-joint coupled motion attitudestabilization

Topic highlight on texture and color enhancement imaging in gastrointestinal diseases

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World Journal of Gastroenterology 2024年第14期30卷 1934-1940页

作者： Osamu Toyoshima toshihiro Nishizawa Keisuke Hata Department of Gastroenterology Toyoshima Endoscopy ClinicTokyo 157-0066Japan Department of Gastroenterology and Hepatology International University of Health and WelfareNarita HospitalNarita 286-8520Japan Department of Gastroenterology Nihonbashi Muromachi Mitsui Tower Midtown ClinicTokyo 103-0022Japan

Olympus Corporation developed texture and color enhancement imaging(TXI)as a novel image-enhancing endoscopic *** topic highlights a series of hot-topic articles that investigated the efficacy of TXI for gastrointestinal disease identification in the clinical setting.A randomized controlled trial demonstrated improvements in the colorectal adenoma detection rate(ADR)and the mean number of adenomas per procedure(MAP)of TXI compared with those of white-light imaging(WLI)observation(58.7%vs 42.7%,adjusted relative risk 1.35,95%CI:1.17-1.56;1.36 vs 0.89,adjusted incident risk ratio 1.48,95%CI:1.22-1.80,respectively).A cross-over study also showed that the colorectal MAP and ADR in TXI were higher than those in WLI(1.5 vs 1.0,adjusted odds ratio 1.4,95%CI:1.2-1.6;58.2%vs 46.8%,1.5,1.0-2.3,respectively).A randomized controlled trial demonstrated non-inferiority of TXI to narrow-band imaging in the colorectal mean number of adenomas and sessile serrated lesions per procedure(0.29 vs 0.30,difference for non-inferiority-0.01,95%CI:-0.10 to 0.08).A cohort study found that scoring for ulcerative colitis severity using TXI could predict relapse of ulcerative colitis.A cross-sectional study found that TXI improved the gastric cancer detection rate compared to WLI(0.71%vs 0.29%).A cross-sectional study revealed that the sensitivity and accuracy for active Helicobacter pylori gastritis in TXI were higher than those of WLI(69.2%vs 52.5%and 85.3%vs 78.7%,res-pectively).In conclusion,TXI can improve gastrointestinal lesion detection and qualitative ***,further studies on the efficacy of TXI in clinical practice are required.

关键词： Endoscopy Texture and color enhancement imaging White-light imaging Narrow-band imaging Colorectal neoplasm Gastric cancer Adenoma Ulcerative colitis Helicobacter infections Colonoscopy

Effects of Direct Switching Dual Bronchodilators between Dry Powder and Soft Mist Inhalers in COPD Patients

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Open Journal of Respiratory Diseases 2020年第1期10卷 11-19页

作者： Taisuke Akamatsu toshihiro Shirai Hiromasa Nakayasu Kanami Tamura toshihiro masuda Shingo Takahashi Yuko Tanaka Hirofumi Watanabe Yutaro Kishimoto Kyohei Oishi Mika Saigusa Akito Yamamoto Satoru Morita Kazuhiro Asada Department of Respiratory Medicine Shizuoka General Hospital Shizuoka Japan

Objective: Dual bronchodilation with long-acting muscarinic antagonist and long-acting β2-agonist combinations are available worldwide in COPD patients. However, the choice of agents remains under debate. We hypothesized that switching devices between dry powder and soft mist inhalers without a wash-out period to mimic clinical practice would improve clinical symptoms and lung function. The aim of this study was to examine the effects of switching between once-daily glycopyrronium/indacaterol (GLY/IND) or umeclidinium/vilanterol (UMEC/VI), dry powder inhalers, and tiotropium/olodaterol (TIO/OLO), a soft mist inhaler, in COPD patients. Methods: This was a prospective, open-label, 8-week, observational study with follow-up. Subjects included 57 COPD patients, who attended outpatient clinics at Shizuoka General Hospital for routine check-ups between February and December 2015, receiving GLY/IND (50/110 μg) or UMEC/VI (62.5/25 μg). After an 8-week run-in period, medications were switched to TIO/OLO (5/5 μg). Study outcomes included patient’s global rating (PGR), modified MRC (mMRC), COPD assessment test (CAT), and spirometric and forced oscillatory parameters after 8 weeks. PGR used in this study was a 7-point scale ranging from 1 to 7, with 4 in the middle. Patients who consented to switch from TIO/OLO to GLY/IND or UMEC/VI were followed-up thereafter. Results: In total, 53 patients completed the study (mean age, 75 years;48 males and 5 females;GOLD 1/2/3/4 = 19/27/6/1;mMRC 0/1/2/3/4 = 14/22/12/4/1;UMEC/VI 26, GLY/IND 27). PGR, mMRC, and CAT improved in 20 (38%), 9 (17%), and 15 patients (28%), respectively. Respiratory system resistance at 5 Hz (R5), 20 Hz (R20), and the difference between R5 and R20 (R5 - R20) significantly improved. In a follow-up of 16 patients after switching from TIO/OLO to UMEC/VI (9) or GLY/IND (7), PGR, mMRC, and CAT improved in 5 (31%), 3 (12%), and 4 patients (25%), respectively, and R20 significantly improved (p = 0.011). Conclusions: Switc

关键词： Device Dry Powder Inhaler Dual Bronchodilator Soft Mist Inhaler Switching

Landscape gradient of autumn photosynthetic decline in Abies sachalinensis seedlings

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Journal of Forestry Research 2023年第1期34卷 187-195页

作者： Tetsuto Sugai Wataru Ishizuka toshihiro Watanabe Hokkaido Research Center Forestry and Forest Products Research InstituteHitsujigaoka 7Sapporo 062-8516Japan Plant Nutrition Laboratory Research Faculty of AgricultureHokkaido UniversitySapporo 060-8689Japan Forest Research Institute Hokkaido Research OrganizationBibaiHokkaido 079-0198Japan

Understanding what environmental factors are genetically linked to a phenologic al event is critical for predicting responses to climate *** synthetic phenology often varies among a species of evergreen conifers due to local ***,few empirical studies have revealed relevant relationships between climatic factors in provenance environments and photosynthetic *** study evaluated the effects of environmental conditions of the growing site and seed source provenance on the seasonal changes in maximal photochemical quantum yield of photo systemⅡ(Fv/Fm)in a common garden experiment with 2-year-old seedlings of Sakhalin fir(Abies sachalinensis),a representative species with local adaptation,from four seed source provenances.A logistic model was constructed to explain the seasonal variation of Fv/Fmfrom July to October and the relationships between the estimated model parameters and representative factors featuring provenance environments were *** landscape gradient of the detected model parameters responsible for the provenance environments was visualized in a map of the distribution *** lowest temperature was the most plausible factor in the growing environment to explain the seasonal changes of Fv/*** the representative meteorological factors of provenance environments,the lowest temperatures in July showed significant relationships with two model parameters,explaining the lower limit of Fv/Fmand the higher sensitivity of autumn Fv/*** estimated spatial maps of model parameters consistently showed that the higher the lowest temperature in July in the provenance environment,the lower the Fv/Fmin October and the greater the decrease in the autumn Fv/***,the lowest summer temperature could be associated with the local adaptation of autumn photosynthetic phenology in ***.

关键词： Phenology Local adaptation Genetic cline Lowest temperature

Kyoto classification of gastritis:Advances and future perspectives in endoscopic diagnosis of gastritis

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World Journal of Gastroenterology 2022年第43期28卷 6078-6089页

作者： Osamu Toyoshima toshihiro Nishizawa Department of Gastroenterology Toyoshima Endoscopy ClinicTokyo 157-0066Japan Department of Gastroenterology and Hepatology International University of Medicine and WelfareNarita 286-8520Japan

This editorial provides an update of the recent evidence on the endoscopy-based Kyoto classification of gastritis,clarifying the shortcomings of the Kyoto classification,and providing prospects for future research,with particular focus on the histological subtypes of gastric cancer(GC)and Helicobacter pylori(***)infection *** total Kyoto score is designed to express GC risk on a score ranging from 0 to 8,based on the following five endoscopic findings:Atrophy,intestinal metaplasia(IM),enlarged folds(EF),nodularity,and diffuse redness(DR).The total Kyoto score reflects *** status as follows:0,≥2,and≥4 indicate a normal stomach,***-infected gastritis,and gastritis at risk for GC,*** arrangement of collecting venules(RAC)predicts noninfection;EF,nodularity,and DR predict current infection;map-like redness(MLR)predicts past infection;and atrophy and IM predict current or past ***,IM,and EF all increase the incidence of ***-infected *** is a specific risk factor for ***-eradicated GC,while RAC results in less ***-type GC can be induced by active inflammation,which presents as EF,nodularity,and atrophy on endoscopy,as well as neutrophil and mononuclear cell infiltration on *** contrast,intestinal-type GC develops via atrophy and IM,and is consistent between endoscopy and ***,this GC risk-scoring design needs to be improved.

关键词： Kyoto classification Gastritis Endoscopy Gastric cancer Histology Helicobacter pylori

Multi-function adsorbent-photocatalyst MXene-TiO_(2) composites for removal of enrofloxacin antibiotic from water

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Journal of Environmental Sciences 2023年第2期124卷 414-428页

作者： Siwanat Sukidpaneenid Chamorn Chawengkijwanich Chonlada Pokhum toshihiro Isobe Pakorn Opaprakasit Paiboon Sreearunothai TAIST-Tokyo Tech Program Sirindhorn International Institute of TechnologyThammasat UniversityPathum Thani 12121Thailand National Nanotechnology Center National Science and Technology Development AgencyPathum Thani 12120Thailand Department of Materials Science and Engineering School of Materials and Chemical TechnologyTokyo Institute of TechnologyTokyo 152-8550Japan School of Bio-Chemical Engineering and Technology Sirindhorn International Institute of TechnologyThammasat UniversityPathum Thani 12121Thailand

MXenes,a new family of two-dimensional transition metal carbides or nitrides,have attracted tremendous attention for various applications due to their unique properties such as good electrical conductivity,hydrophilicity,and ion *** this work,Ti_(3)C_(2) MXene,or MX,is converted to MX-TiO_(2) composites using a simple and rapid microwave hydrothermal treatment in HCl/NaCl mixture solution that induces formation of fine TiO_(2) particles on the MX parent structure and imparts photocatalytic activity to the resulting MX-TiO_(2) *** composites were used for enrofloxacin(ENR),a frequently found contaminating antibiotic,removal from *** relative amount of the MX and TiO_(2) can be controlled by controlling the hydrothermal temperature resulting in composites with tunable adsorption/photocatalytic *** addition was found to play important role as composites synthesized without NaCl could not adsorb enrofloxacin *** NaCl into the hydrothermal treatment causes sodium ions to be simultaneously intercalated into the composite structure,improving ENR adsorption greatly from 1 to 6 mg ENR/g *** also slows down the MX to TiO2 conversion leading to a smaller and more uniform distribution of TiO_(2) particles on the ***-TiO_(2)/NaCl composites,which have sodium intercalated in their structures,showed both higher ENR adsorption and photocatalytic activity than composites without NaCl despite the latter having higher TiO2 *** ENR on the composites can be efficiently degraded by free radicals generated from the photoexcited TiO2 particles,leading to high photocatalytic degradation *** demonstrates the synergetic effect between adsorption and photocatalytic degradation of the synthesized compounds.

关键词： MXene-TiO_(2)composites Ti3C2 Ion-exchange Photocatalytic degradation Enrofloxacin Antibiotics removal

Flow field, heat transfer and inclusion behavior in a round bloom mold under effect of a swirling flow submerged entry nozzle

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Journal of Iron and Steel Research(International) 2023年第6期30卷 1211-1221页

作者： Qing-hua Xie Pei-yuan Ni toshihiro Tanaka Mikael Ersson Ying Li Key Laboratory of Ecological Metallurgy of Multi-metal Intergrown Ores of Ministry of Education School of MetallurgyNortheastern UniversityShenyang 110819LiaoningChina Liaoning Key Laboratory of Metallurgical Sensor Materials and Technology School of MetallurgyNortheastern UniversityShenyang 110819LiaoningChina Graduate School of Engineering Osaka UniversityOsaka 565-0871Japan Department of Materials Science and Engineering KTH Royal Institute of TechnologyStockholm 10044Sweden

Flow field,heat transfer and inclusion behavior in a 700 mm round bloom mold under the effect of a swirling flow submerged entry nozzle(SEN)were investigated with the aim to enhance the casting *** results indicate that the impinging flow phenomenon,which is commonly observed in conventional single-port SEN casting,was completely suppressed by the swirling flow SEN coming from a novel swirling flow generator design in *** from the SEN port moved towards the mold wall in 360 direction,leading to a uniform temperature distribution in the *** to a conventional single-port SEN casting,the steel super-heat was decreased by about 5 K at the mold center,and the temperature was increased by around 3.5 K near the *** addition,the removal ratio of inclusions to the mold top surface in the swirling flow SEN casting was found to be ***,the removal ratio of spherical inclusions with diameters of 1,10,50 and 100μm was increased by 18.2%,18.5%,22.6% and 42.7%,***,the ratio was raised by 18.2%,20.8%,21.5% and 44.1%for non-spherical inclusions,respectively.

关键词： Large round bloom Swirling flow submerged entry nozzle casting Flow field Heat transfer Inclusion behavior

On Exit Time from Balls of Jump-type Symmetric Markov Processes

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Acta Mathematica Sinica,English Series 2010年第1期26卷 185-192页

作者： toshihiro UEMURA Department of Mathematics Faculty of Engineering Science Kansai University

We obtain upper and lower bounds of the exit times from balls of a jump-type symmetric Markov process. The proofs are delivered separately. The upper bounds are obtained by using the Levy system corresponding to the process, while the precise expression of the （L^2-）generator of the Dirichlet form associated with the process is used to obtain the lower bounds.

关键词： symmetric Dirichlet form jump-type Markov process Levy system exit times from balls