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Possibility of avoiding legumes-deriving boost of N 2 O emissions in tropical monoculture tree plantations

Journal of Forestry Research 2023年第2期34卷 565-573页

作者： Taiki Mori Chongrak Wachrinrat Duriya Staporn ryota aoyagi Ponthep Meunpong Warawich Suebsai Khitja Boonsri Kanehiro Kitayama Forest Ecology Laboratory Graduate School of AgricultureKyoto UniversityKitashirakawa Oiwake-cho Sakyo-kuKyoto 606-8502Japan Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems South China Botanical GardenChinese Academy of SciencesGuangzhou 510650GuangdongPeople’s Republic of China Forestry and Forest Products Research Institute FFPRI 1 MatsunosatoTsukubaIbaraki 305-8687Japan Faculty of Forestry Kasetsart UniversityChatuchakBangkok 10900Thailand Smithsonian Tropical Research Institute Bocas TownIsla AncónRepublic of Panama

Recent reports warned that planting leguminous trees under monocultures elevates nitrous oxide(N2O)emissions through N-rich litter inputs.We hypothesized that planting trees on sandy soil can avoid the legume-derived boost of N2O emissions through limiting water availability for N2O production.Effects of planting legumes on methane(CH4)uptakes were also examined.N2O emissions and CH4uptakes were compared among five tropical tree plantation stands including three leguminous stands(Acacia auriculiformis,Acacia mangium,and Xylia xylocarpa)and two non-leguminous stands(Eucalyptus camaldulensis,and Hope a odorata).Due to lower water contents of the soil,the N2O fluxes in our study site were at the lower end of the tropical rain forests.As we hypothesized,no clear differences in N2O emissions were obs erved between leguminous and non-leguminous stands.CH4uptake rates in the present study were lower than those of other tropical forests.CH4uptakes in leguminous stands did not differ from those in non-leguminous stands.Overall,we demonstrated that planting leguminous trees on sandy soils has a potential to enable us to manage leguminous monoculture tree plantations without boosting N2O emissions or reducing CH4uptakes.

关键词： Nitrous oxide Methane Fast-growing trees Tropical forest Soil texture

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Evaluation of excavation damaged zones(EDZs)in Horonobe Underground Research Laboratory(URL)

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 365-378页

作者： Koji Hata Sumio Niunoya Kazuhei aoyagi Nobukatsu Miyara Obayashi Corporation Technology Research InstituteTechnology DivisionKiyoseTokyo204-8558Japan Obayashi Corporation Nuclear Facilities DivisionSinagawaTokyo108-8502Japan Japan Atomic Energy Agency Horonobe Underground Research CenterHoronobeHokkaido098-3224Japan

Excavation of underground caverns,such as mountain tunnels and energy-storage caverns,may cause the damages to the surrounding rock as a result of the stress redistribution.In this influenced zone,new cracks and discontinuities are created or propagate in the rock mass.Therefore,it is effective to measure and evaluate the acoustic emission(AE)events generated by the rocks,which is a small elastic vibration,and permeability change.The authors have developed a long-term measurement device that incorporates an optical AE(O-AE)sensor,an optical pore pressure sensor,and an optical temperature sensor in a single multi-optical measurement probe(MOP).Japan Atomic Energy Agency has been conducting R&D activities to enhance the reliability of high-level radioactive waste(HLW)deep geological disposal technology.In a high-level radioactive disposal project,one of the challenges is the development of methods for long-term monitoring of rock mass behavior.Therefore,in January 2014,the long-term measurements of the hydro-mechanical behavior of the rock mass were launched using the developed MOP in the vicinity of 350 m below the surface at the Horonobe Underground Research Center.The measurement results show that AEs occur frequently up to 1.5 m from the wall during excavation.In addition,hydraulic conductivity increased by 2e4 orders of magnitude.Elastoplastic analysis revealed that the hydraulic behavior of the rock mass affected the pore pressure fluctuations and caused micro-fractures.Based on this,a conceptual model is developed to represent the excavation damaged zone(EDZ),which contributes to the safe geological disposal of radioactive waste.

关键词： Excavation damaged zone(EDZ) Optical sensor Long-term monitoring Acoustic emission(AE) Shaft sinking

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Effect of mechanical ball milling on the electrical and powder bed properties of gas-atomized Ti-48Al-2Cr-2Nb and elucidation of the smoke mechanism in the powder bed fusion electron b eam melting process

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Journal of Materials Science & Technology 2023年第6期137卷 36-55页

作者： Seungkyun Yim Kenta aoyagi Keiji Yanagihara Huakang Bian Akihiko Chiba Institute for Materials Research Tohoku University2-1-1 KatahiraSendaiMiyagi 980-8577Japan

Smoke is unexpected powder-splashing caused by electrostatic force and is one of the main problems hindering the process stability and applicability of the powder bed fusion electron beam(PBF-EB)tech-nology.In this study,mechanical stimulation was suggested to suppress smoke of gas-atomized(GA)Ti-48Al-2Cr-2Nb powder using Al_(2)O_(3) and WC ball milling.The deformation mechanism of the GA powder depending on the ball milling media was discussed based on the developed particle morphology distribu-tion map and contact mechanics simulation.It was revealed that the rapid decrement of flowability and packing density after WC ball milling owing to the formation of angular fragments by the brittle fracture.The variation of surface and electrical properties by mechanical stimulation was investigated via XPS,TEM,and Impedance analysis.The electrical resistivity of the ball-milled powders gradually decreased with increasing milling duration,despite the increased oxide film thickness,and the capacitive response disappeared in Al-60 and WC-30 via metal-insulator transition.This could be due to the accumulation of strain and defects on the oxide film via mechanical stimulation.The smoke mechanism of ball-milled powders was discussed based on the percolation theory.In the smoke experiment,smoke was more suppressed for WC-10 and WC-20 than that for Al-40 and Al-50,respectively,despite the longer charge dissipation time.This could be due to the high probability of contact with conductive particles.For the Al-60 and WC-30 powders,smoke was further restricted by the formation of a percolation cluster with metal-like electrical conductivity.We believe that this study will contribute to a better understanding of the smoke mechanism and process optimization of the PBF-EB.

关键词： Metal-insulator transition Electron beam melting additive manufacturing Packing density Flowability Smoke mechanism Percolation theory

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Nitrifiers activity and community characteristics under stress conditions in partial nitrification systems treating ammonium-rich wastewater

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Journal of Environmental Sciences 2018年第11期30卷 1-8页

作者： Jia Miao Qidong Yin Tomoyuki Hori Tomo aoyagi Hiroshi Habe Guangxue Wu Guangdong Province Engineering Research Center for Urban Water Recycling and Environmental Safety Graduate School at ShenzhenTsinghua University Environmental Management Research Institute National Institute of Advanced Industrial Science and Technology(AIST)

Long-term exposure of nitrifiers to high concentrations of free ammonia （FA） and free nitrous add （FNA） may affect nitrifiers activity and nitrous oxide （N2O） emission. Two sequencing batch reactors （SBRs） were operated at influent ammonium nitrogen （NH4-N） concentrations of 800 mg/L （SBRH） and 33S mg/L （SBRL）, respectively. The NH4-N removal rates in SBRH and SBRL were around 2.4 and 1.0 g/L/day with the nitritation efficiencies of 99.3% and 95.7%, respectively. In the simulated SBR cycle, the N20 emission factors were 1.61% in SBRH and 2.30% in SBRL. N2O emission was affected slightly by FA with the emission factor of 0.22%-0.65%, while N2O emission increased with increasing FNA concentrations with the emission factor of 0.22%～3.96%. The dominant ammonia oxidizing bacteria （AOB） were Nitrosomonas spp. in both reactors, and their relative proportions were 38.89% in SBRH and 13.36% in SBRL. Within the AOB genus, a species （i.e., operational taxonomic unit [OTU] 76） that was phylogenetically identical to Nitrosomonas europaea accounted for 99.07% and 82.04% in SBRH and SBRL, respectively. Additionally, OTU 215, which was related to Nitrosomonas stercoris, accounted for 16.77% of the AOB in SBRL.

关键词： Ammonium-rich wastewater Free ammonia Free nitrous acid N2O emission Partial nitrification

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Isothermal γ →ε phase transformation behavior in a Co-Cr-Mo alloy depending on thermal history during electron beam powder-bed additive manufacturing

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Journal of Materials Science & Technology 2020年第15期47卷 162-170页

作者： Yufan Zhao Yuichiro Koizumi Kenta aoyagi Kenta Yamanaka Akihiko Chiba Department of Materials Processing Graduate School of EngineeringTohoku UniversityAoba-yama 02Aoba-kuSendai980-8579Japan Institute for Materials Research Tohoku University2-1-J KatahiraAoba-kuSendai980-8577Japan

Powder bed fusion with electron beam(PBF-EB),allows Co-Cr-Mo(CCM) implants with patientcustomization to be fabricated with high quality and complex geometry.However,the variability in the properties of PBF-EB-built CCM alloy,mainly due to the lack of understanding of the mechanisms that govern microstructural heterogeneity,brings limitations in extensive application.In this study,the microstructural heterogeneity regarding the γ-fcc→ε-hcp phase transformation was characterized.The phase transformation during PBF-EB was analyzed depending on the thermal history that was elucidated by the numerical simulation.It revealed that isothermal γ→ε transformation occurred during the fabrication.Importantly,the difference in γ/ε phase distribution was a result of the thermal history determining which method phase transformation was taking place,which can be influenced by the PBF-EB process parameters.In the sample with a low energy input(Earea=2.6 J/mm2),the martensitic transformation was dominant.As the building height increased from the bottom,the e phase fraction decreased.On the other hand,in the sample with a higher energy input(Earea=4.4 J/mm2),the ε phase fo rmed via diffusional-massive transformation and only appea red in a short range of the lower part away from the bottom.

关键词： Powder bed fusion with electron beam Phase transformation Thermal history Numerical simulation

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Effects of the aluminum concentration on twin boundary motion in pre-strained magnesium alloys

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Journal of Materials Science & Technology 2021年第14期73卷 116-127页

作者： Yujie Cui Kenta aoyagi Huakang Bian Yuichiro Hayasaka Akihiko Chiba Institute for Materials Research Tohoku UniversitySendai 980-8577Japan The Electron Microscopy Center Tohoku UniversitySendai 980-8577Japan

We investigated the effects of Al concentration on the reciprocated motion of twin boundaries in pre-strained Mg-Al-Zn alloys through a combination of applied compression and tension,in-situ electron-backscattering diffraction observations,and high-angle annular dark-field scanning transmission electron microscopy observations.The twin growth was restricted by increased Al concentration,which resulted in the occurrence of smaller-sized twins.The reverse motion of twin boundaries was also restricted,resulting in the formation of higher fractions of secondary twins and 2–5°boundaries during reverse tension.The secondary twins and 2–5°boundaries mainly contributed to the increased ultimate tensile strength of the pre-strained Mg alloys.This effect is more significant in Mg alloys with larger pre-compression.Moreover,the increased amount of the Al solute atoms,rather than the precipitates,mainly contributed to the increased strengthening effect on the twin boundary motion.Our research contributes to development of high-strength Mg alloys by stabilizing twin boundaries.

关键词： Hexagonal close packed Magnesium alloy Twinning Dislocations Strength Solute atoms

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Gene expression and pathway analysis of CTNNB1 in cancer and stem cells

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World Journal of Stem Cells 2016年第11期8卷 384-395页

作者： Shihori Tanabe Takeshi Kawabata Kazuhiko aoyagi Hiroshi Yokozaki Hiroki Sasaki Division of Risk Assessment National Institute of Health Sciences Laboratory of Protein Informatics Institute for Protein Research Osaka University Department of Translational Oncology National Cancer Center Research Institute Department of Pathology Kobe University of Graduate School of Medicine

AIM To investigate β-catenin(CTNNB1) signaling in cancer and stem cells, the gene expression and pathway were analyzed using bioinformatics.METHODS The expression of the catenin β 1(CTNNB1) gene, which codes for β-catenin, was analyzed in mesenchymal stem cells(MSCs) and gastric cancer(GC) cells. Beta-catenin signaling and the mutation of related proteins were also analyzed using the cB ioP ortal for Cancer Genomics and HOMology modeling of Complex Structure(HOMCOS) databases.RESULTS The expression of the CTNNB1 gene was up-regulated in GC cells compared to MSCs. The expression of EPH receptor A8(EPHA8), synovial sarcoma translocation chromosome 18(SS18), interactor of little elongation complex ELL subunit 1(ICE1), patched 1(PTCH1), mutS homolog 3(MSH3) and caspase recruitment domain family member 11(CARD11) were also shown to be altered in GC cells in the cB ioP ortal for Cancer Genomics analysis. 3D complex structures were reported for E-cadherin 1(CDH1), lymphoid enhancer binding factor 1(LEF1), transcription factor 7 like 2(TCF7L2) and adenomatous polyposis coli protein(APC) with β-catenin. CONCLUSION The results indicate that the epithelial-mesenchymal transition(EMT)-related gene CTNNB1 plays an important role in the regulation of stem cell pluripotency and cancer signaling.

关键词： β-catenin CTNNB1 Epithelial-mesenchymal transition Mesenchymal stem cell Stem cell

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Cancer cachexia,mechanism and treatment

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World Journal of Gastrointestinal Oncology 2015年第4期7卷 17-29页

作者： Tomoyoshi aoyagi Krista P Terracina Ali Raza Hisahiro Matsubara Kazuaki Takabe Division of Surgical Oncology Department of SurgeryVirginia Commonwealth University School of Medicine and the Massey Cancer Center Department of Frontier Surgery Graduate School of Medicine Chiba University

It is estimated that half of all patients with cancer eventually develop a syndrome of cachexia, with anorexia and a progressive loss of adipose tissue and skeletal muscle mass. Cancer cachexia is characterized by systemic inflammation, negative protein and energy balance, and an involuntary loss of lean body mass. It is an insidious syndrome that not only has a dramatic impact on patient quality of life, but also is associated with poor responsesto chemotherapy and decreased survival. Cachexia is still largely an underestimated and untreated condition, despite the fact that multiple mechanisms are reported to be involved in its development, with a number of cytokines postulated to play a role in the etiology of the persistent catabolic state. Existing therapies for cachexia, including orexigenic appetite stimulants, focus on palliation of symptoms and reduction of the distress of patients and families rather than prolongation of life. Recent therapies for the cachectic syndrome involve a multidisciplinary approach. Combination therapy with diet modification and/or exercise has been added to novel pharmaceutical agents, such as Megestrol acetate, medroxyprogesterone, ghrelin, omega-3-fatty acid among others. These agents are reported to have improved survival rates as well as quality of life. In this review, we will discuss the emerging understanding of the mechanisms of cancer cachexia, the current treatment options including multidisciplinary combination therapies, as well an update on new and ongoing clinical trials.

关键词： Physical exercise Pharmacological treatment Cancer cachexia

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Characterization of CD133^+ parenchymal cells in the liver:Histology and culture

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World Journal of Gastroenterology 2009年第39期15卷 4896-4906页

作者： Seiichi Yoshikawa Yoh Zen Takahiko Fujii Yasunori Sato Tetsuo Ohta Yutaka aoyagi Yasuni Nakanuma Department of Human Pathology Kanazawa University Graduate School of Medicine Division of Gastro-enterology and Hepatology Niigata University Graduate School of Medical and Dental Sciences Division of Pathology Kanazawa University Hospital Department of Gastrointestinal Surgery Kanazawa University Graduate School of Medicine

AIM:To reveal the characteristics of CD133+ cells in the liver.METHODS:This study examined the histological characteristics of CD133+ cells in non-neoplastic and neoplastic liver tissues by immunostaining,and also analyzed the biological characteristics of CD133+ cells derived from human hepatocellular carcinoma(HCC) or cholangiocarcinoma cell lines.RESULTS:Immunostaining revealed constant expression of CD133 in non-neoplastic and neoplastic biliary epithelium,and these cells had the immunophenotype CD133+/CK19+/HepPar-1-.A small number of CD133+/CK19-/HepPar-1+ cells were also identified in HCC and combined hepatocellular and cholangiocarcinoma.In addition,small ductal structures,resembling the canal of Hering,partly surrounded by hepatocytes were positive for CD133.CD133 expression was observed in three HCC(HuH7,PLC5 and HepG2) and two cholangiocarcinoma cell lines(HuCCT1 and CCKS1).Fluorescence-activated cell sorting(FACS) revealed that CD133+ and CD133-cells derived from HuH7 and HuCCT1 cells similarly produced CD133+ and CD133-cells during subculture.To examine the relationship between CD133+ cells and the side population(SP) phenotype,FACS was performed using Hoechst 33342 and a monoclonal antibody against CD133.The ratios of CD133+/CD133-cells were almost identical in the SP and non-SP in HuH7.In addition,four different cellular populations(SP/CD133+,SP/CD133-,non-SP/CD133+,and non-SP/CD133-) could similarly produce CD133+ and CD133-cells during subculture.CONCLUSION:This study revealed that CD133 could be a biliary and progenitor cell marker in vivo.However,CD133 alone is not sufficient to detect tumor-initiating cells in cell lines.

关键词：肝实质细胞组织学表征文化

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Parental expectation of early childhood education: comparison between China, Japan, and Korea

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Frontiers of Education in China 2007年第1期2卷 140-147页

作者： ZHOU Aibao MA Xiaofeng aoyagi Hajime Department of Psychology Northwest Normal UniversityLanzhou 730070China School of Human Sciences Waseda UniversityTokyoJapan

This study investigates 727 parents from China, Japan, and Korea by a self-devised scale and compares the differences in their expectation of early childhood education in cross-cultural backgrounds. The result shows that parents from the three countries have a positive attitude toward their children’s development. The main effect of nations on such factors as individual development, close attention to diet, willpower training, moral judgment, and emotional exchange with adults is significant, while the two-way interaction between nations and child gender, nations and child age, and the three-way interaction between nations, child gender, and child age are not significant.

关键词： parental expectation nations child gender child age early childhood education cross-cultural comparison

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