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Depositional condition of Paleoproterozoic Francevillian carbonate rocks revisited from rare earth element contents

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Geoscience Frontiers 2024年第3期15卷 31-49页

作者： Satoshi Yoshida Karen Bakakas Mayika Yuki Ishihara Mathieu Moussavou Hisashi Asanuma Tomohiko Sato Takafumi hirata Cédric Ligna Yusuke Sawaki Amboise Edou-Minko Department of Earth Science and Astronomy The University of Tokyo3-8-1 Komaba Meguro-kuTokyo 153-8902Japan Center for Northeast Asian Studies Tohoku University41 KawauchiAoba-kuSendai 980-8576Japan Department of Geology Universitédes Sciences et Techniques de MasukuBP:90190025 FrancevilleGabon Department of Earth and Planetary Science The University of Tokyo7-3-1 HongoBunkyo-kuTokyo 113-0033Japan Geochemical Research Center The University of Tokyo7-3-1HongoBunkyo-kuTokyo 113-0033Japan Graduate School of Human and Environmental Studies Kyoto UniversityYoshida-nihonmatsuSakyo-kuKyoto 606-8501Japan Center for Fundamental Education Okayama University of Science1-1Ridai-choKita-kuOkayama CityOkayama 700-0005Japan

The Paleoproterozoic Francevillian Group in the eastern Gabonese Republic has been recently attracting increasing attention because it includes distinctive macroscopic structures interpreted as eukaryotic ***,its depositional setting and associated redox conditions need to be clearly *** clarify these,petrological studies and rare earth element(REE)abundances of carbonate rocks of the Francevillian Group in the Lastoursville basin were determined with ICP-MS coupled with a laser ablation sampling *** microscopic observations indicate that dolostones in this basin underwent the complicated diagenetic history,including sparitization,decomposition of organic matter,reduction of ferromanganese oxides,silicification,and later *** dolostones of lower Francevillian B(FB)Formation show heterogeneous textures formed by alterations during *** the alterations,changes of REE abundances and degrees of positive Y anomalies appear to have *** indicates that REE signatures in carbonate rocks can vary during *** high Mn contents in the dolostones of upper FB Formation were derived from the reduction of ferromanganese oxides in *** signatures of REE abundance in dolostones can be explained by the mixing of seawater and ferromanganese oxide *** that sense,the dolostones inherited the trace element characteristics of precursor ferromanganese oxides even after the diagenesis.Y/Ho values of the most primary parts of each sample exceed 33,the newly determined threshold value for marine carbonate rocks based on our *** magnitude of the La anomaly values also falls within the range of that of Holocene reefal *** indicate that a precursor of the dolostone of the Francevillian Group was deposited in a marine *** addition,presence of Ce anomalies in the upper FB Formation suggests that the Paleoproterozoic ocean was oxidized to such an ex

关键词： Carbonate diagenesis Francevillian Group LA-ICP-MS Seawater composition Y/Ho fractionation

Physicochemical properties of Li_(3)Ba_(2)La_(3)(MoO_(4))_(8):Eu,Tb red-emitting phosphor for solid state white lamps

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稀土学报:英文版 2023年第9期41卷 1279-1287,I0001页

作者： Kora Lu Rojas Baldivia Gustavo A.hirata Center for Scientific Research and Higher Education of Ensenada Ensenada Baja California 22860Mexico Center for Nanoscience and Nanotechnology National Autonomous University of Mexico EnsenadaBaja Califomia 22860Mex

In this work,combustion synthesis was used for the first time to fabricate a phosphor material with red emission for applications in solid-state white-light *** synthesized a material with emission wavelength at λ_(em)=617 nm,excited under long UV-blue wavelength based on Eu^(3+),Tb^(3+)-activated molybdates Li_(3)Ba_(2)(La_(1-x-y)Eu_(x)Tb_(y))_(3)(MoO_(4))_(8) with 0 ≤ x ≤1 and 0 ≤ y ≤ 1.A series of powder samples were produced by the combustion method and post-annealed at 800℃ in *** crystalline phase formation was investigated by X-ray diffraction,which reveals the monoclinic C2/c(15) space *** is observed that crystalline structure and morphology are preserved when the host lattice is doped with Eu^(3+) or Tb^(3+) single ions and co-doped with both ions at different doping concentrations.A detailed characterization by scanning electron microscopy(SEM) and transmission electron microscopy(TEM)shows a similar morphology in all samples:rather large(1-7 μm) agglomerate particles with irregular shapes and surrounded by smaller nanoparticles of 50 nm in ***-visible absorption spectra confirm the presence of Eu^(3+) and Tb^(3+) *** luminescent properties of the obtained phosphors were studied in *** measurements indicate that the best emission intensity is for Eu^(3+):Tb^(3+)doping ratios of 80:0,90:0 and 20:*** the other hand,samples with 80:0,60:40,and 20:80 doping ratios show the highest intensity in a detailed photoluminescence analysis and they exhibit the highest quantum yield values.A complete and efficient energy transfer from the sensitizer Tb^(3+) to the activator Eu^(3+) is observed in all co-doped phosphors post-annealed at 800℃ for 4 ***,the Li_(3)Ba_(2)La_(3)(MaO_(4))_(8):Eu^(3+),Tb^(3+) materials fabricated by combustion synthesis are excellent phosphors for being applied as red-emitting component in solid-state white-light lamps due to an improved color rendering index(CRI) that can be obtained under lo

关键词： Molybdate Europium Terbium Luminescence Phosphor-converted LED Rare earths

Characteristics and predictors of gastric cancer after Helicobacter pylori eradication

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World Journal of Gastroenterology 2018年第20期24卷 2163-2172页

作者： Satoki Shichijo Yoshihiro hirata Department of Gastrointestinal Oncology Osaka International Cancer Institute Division of Advanced Genome Medicine The Institute of Medical Science The University of Tokyo

Helicobacter pylori(H. pylori) eradication can reduce gastric cancer. However, gastric cancer still develops after eradication, and cases who received eradication therapy are increasing. In this study, we have reviewed the characteristics and predictors of primary gastric cancer developing after H. pylori eradication. In terms of the characteristics, endoscopic, histologic, and molecular characteristics are reported. Endoscopically, gastric cancer after eradication is often depressedtype and shows a gastritis-like appearance, which sometimes makes the diagnosis difficult. Histologically, most gastric cancer after eradication is intestinal type, and non-neoplastic epithelium, also called epithelium with low-grade atypia, is frequently seen over the tumor, which is presumably the cause of the endoscopic gastritis-like appearance. As for molecular characteristics, some markers, such as Ki67, MUC2, and Wnt5a expression, are lower in cancer from patients in whom H. pylori has been eradicated. In terms of predictors, several Japanese studies have reported that severe endoscopic atrophy at eradication is a risk factor for gastric cancer development. Histologic intestinal metaplasia, especially in the corpus, and long-term use of proton pump inhibitors, are also reported as risk factors for gastric cancer after H. pylori eradication. These studies on the characteristics and predictors of gastric cancer development will become the cornerstone for establishing a novel surveillance program based on the gastric cancer risk stratification specific to H. pylori-eradicated patients.

关键词： gastric cancer eradication characteristic Helicobacter pylori predictor

Decolorization of Orange Ⅱ using an anaerobic sequencing batch reactor with and without co-substrates

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Journal of Environmental Sciences 2012年第2期24卷 291-296页

作者： Soon-An Ong Eiichi Toorisaka Makoto hirata Tadashi Hano Department of Applied Chemistry OitaUniversity School of Environmental Engineering University Malaysia Perlis

We investigated the decolorization of Orange Ⅱ with and without the addition of co-substrates and nutrients under an anaerobic sequencing batch reactor（ASBR）.The increase in COD concentrations from 900 to 1750 to 3730 mg/L in the system treating 100 mg/L of Orange Ⅱ-containing wastewater enhanced color removal from 27% to 81% to 89%,*** the absence of co-substrates and nutrients,more than 95% of decolorization was achieved by the acclimatized anaerobic microbes in the bioreactor treating 600 mg/L of Orange Ⅱ.The decrease in mixed liquor suspended solids concentration by endogenous lysis of biomass preserved a high reducing environment in the ASBR,which was important for the reduction of the Orange Ⅱ azo bond that caused *** maximum decolorization rate in the ASBR was approximately 0.17 g/hr in the absence of co-substrates and nutrients.

关键词： anaerobic reduction azo dye decolorization rate endogenous lysis Orange Ⅱ

Combination of adsorption and biodegradation processes for textile effluent treatment using a granular activated carbon-biofilm configured packed column system

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Journal of Environmental Sciences 2008年第8期20卷 952-956页

作者： ONG SoonAn TOORISAKA Eiichi hirata Makoto HANO Tadashi Department of Applied Chemistry Oita UniversityOita 870-1192Japan.School of Environmental EngineeringUniversity Malaysia PerilsPerlis 02700Malaysia Department of Applied Chemistry Oita UniversityOita 870-1192Japan

The objective of this study was to investigate the feasibility of using a granular activated carbon-biofilm configured packed column system in the deeolodzation of azo dye Acid Orange 7-containing *** Acid Orange 7-degrading microbial from anaerobic sequencing batch reactor which treating the azo dye-containing wastewater for more than 200 d was immobilized on spent granular activated carbon(GAC)through *** GAC-biofilm configured packed column system showed the ability to decolorize 10...

关键词： granular activated carbon(GAC) color removal Acid Orange 7 azo dye immobilization

Three-Dimensional Lattice Boltzmann Simulation of Two-Phase Flow Containing a Deformable Body with a Viscoelastic Membrane

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Communications in Computational Physics 2011年第5期9卷 1397-1413页

作者： Toshiro Murayama Masato Yoshino Tetsuo hirata Department of Mathematics and System Development Engineering Interdisciplinary Graduate School of Science and TechnologyShinshu University4-17-1 WakasatoNagano-shiNagano 380-8553Japan Satellite Venture Business Laboratory(SVBL) Shinshu University3-15-1 TokidaUeda-shiNagano 386-8567Japan Department of Mechanical Systems Engineering Faculty of EngineeringShinshu University4-17-1 WakasatoNagano-shiNagano 380-8553Japan CREST Japan Science and Technology Agency4-1-8 HonchoKawaguchi-shiSaitama 332-0012Japan

The lattice Boltzmann method(LBM)with an elastic model is applied to the simulation of two-phase flows containing a deformable body with a viscoelastic *** numerical method is based on the LBM for incompressible two-phase fluid flows with the same *** body has an internal fluid covered by a viscoelastic membrane of a finite *** elastic model is introduced to the LBM in order to determine the elastic forces acting on the viscoelastic membrane of the *** the present method,we take account of changes in surface area of the membrane and in total volume of the body as well as shear deformation of the *** using this method,we calculate two problems,the behavior of an initially spherical body under shear flow and the motion of a body with initially spherical or biconcave discoidal shape in square pipe *** deformations of the body(the Taylor shape parameter)for various shear rates are in good agreement with other numerical ***,tank-treading motion,which is a characteristic motion of viscoelastic bodies in shear flows,is simulated by the present method.

关键词： Lattice Boltzmann method(LBM) two-phase flow viscoelastic membrane shear flow tank-treading motion

Duodenal intussusception secondary to ampullary adenoma: A case report

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World Journal of Clinical Cases 2019年第14期7卷 1857-1864页

作者： Masaaki hirata Yoshiharu Shirakata Kenya Yamanaka Department of Surgery Hyogo Prefectural Amagasaki General Medical CenterAmagasakiHyogo 660-0892Japan

BACKGROUND Because the duodenum is fixed onto the retroperitoneum, duodenal intussusception is usually impossible except in cases of malrotational abnormality. Although cases of duodenal intussusception without malrotational abnormalities have been reported, it is unclear whether they constitute true intussusception or simple mucosal prolapse. CASE SUMMARY A 66-year-old woman presented with whole-body edema and malaise. Blood analysis indicated severe anemia and cholestasis. Endoscopic examination revealed a pedunculate polyp on the second part of the duodenum that migrated distally with mucosal elongation. Computed tomography showed duodenal intussusception. A tumor as the lead point and retroperitoneal structure, including the head of the pancreas and fat, invaginated beyond the duodenojejunal flexure. She was diagnosed with ampullary adenoma caused repeated intussusception that reduced spontaneously and underwent pancreaticoduodenectomy. Laparotomy showed tumor prolapse beyond the duodenojejunal flexure without intussusception. There was no evidence of malrotational abnormality. She was discharged with no complications. CONCLUSION We report true duodenal intussusception without malrotational abnormality. This phenomenon was also associated with mucosal prolapse.

关键词： Duodenal intussusception Mucosal prolapse Ampullary adenoma Case report

Mathematically modelling and controlling prostate cancer under intermittent hormone therapy

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Asian Journal of Andrology 2012年第2期14卷 270-277页

作者： Yoshito hirata Gouhei Tanaka Nicholas Bruchovsky Kazuyuki Aihara Institute of Industrial Science University of Tokyo Tokyo 153-8505 Japan Vancouver Prostate Centre Vancouver General Hospital Vancouver BC V6H 3Z6 Canada

In this review, we summarize our recently developed mathematical models that predict the effects of intermittent androgen suppression therapy on prostate cancer （PCa）. Although hormone therapy for PCa shows remarkable results at the beginning of treatment, cancer cells frequently acquire the ability to grow without androgens during long-term therapy, resulting in an eventual relapse. To circumvent hormone resistance, intermittent androgen suppression was investigated as an alternative treatment option. However, at the present time, it is not possible to select an optimal schedule of on- and off-treatment cycles for any given patient. In addition, clinical trials have revealed that intermittent androgen suppression is effective for some patients but not for others. To resolve these two problems, we have developed mathematical models for PCa under intermittent androgen suppression. The mathematical models not only explain the mechanisms of intermittent androgen suppression but also provide an optimal treatment schedule for the on- and off-treatment periods.

关键词： diagnosis intermittent androgen suppression mathematical models personalized treatment schedule prognosis prostate cancer

Quantitative evaluation of die casting surface defect severity by analyzing surface height

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China Foundry 2017年第5期14卷 339-345页

作者： Yan Xu Naoya hirata Koichi Anzai Department of Metallurgy Graduate School of EngineeringTohoku UniversitySendai 980-85 79Japan

It is necessary in factories to assess the severity of the surface defects of castings, as a slight surface defect will be taken as qualified when it brings no bad effect or it can be removed by the subsequent processing. In practical production, professional technicians visually inspect the surface defect severity according to their individual experience. Therefore, it is difficult for them to maintain the same standard and accuracy in the subjective, tedious and labor-intensive work. Recently, image processing techniques based on optical images have been applied to achieve better accuracy and high efficiency. Unfortunately, optical images cannot directly quantify surface depth, which works as a crucial factor in the practical assessment of surface defect severity. The surface roughness evaluation algorithm, which takes into account of both area and depth information of the assessed surface, was applied to directly characterize surface defect severity based on surface asperity rather than optical image. The results using standard casting pieces show that surface defect severity has no apparent dependence on surface roughness. However, the subsequent results show that the root-mean-squared-deviation(RMSD) of surface gradient of flow line defects positively correlates with the increase of defect severity. The other types of defect do not present such tendency. Thus, practical workpieces with flow line defects on the surface were used to verify the universality of this tendency. The results show that surface roughness of an unqualified workpiece is larger than that of a qualified workpiece after surface slope adjustment, but presents no obvious coincidence before the adjustment. In contrast, the RMSD of an unqualified workpiece, no matter before or after the adjustment, is larger than that of a qualified one.

关键词： die casting surface defect surface roughness