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A prolonged granitoid formation in Saglek Block,Labrador:Zonal growth and crustal reworking of continental crust in the Eoarchean

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Geoscience Frontiers 2017年第2期8卷 355-385页

作者： Tsuyoshi Komiya Shinji Yamamoto Shogo Aoki Keiko Koshida Masanori Shimojo Yusuke Sawaki Kazumasa Aoki Shuhei Sakata Takaomi D.Yokoyama kenshi maki Akira Ishikawa Takafumi Hirata Kenneth D.Collerson Department of Earth Science and Astronomy Graduate School of Arts and SciencesThe University of TokyoTokyo 153-8902Japan Department of Earth and Planetary Sciences Tokyo Institute of Technology2-12-1 OokayamaMeguroTokyo 152-8551Japan Laboratory for Planetary Sciences Kyoto UniversityKitashirakawa OiwakechoKyoto 606-8502Japan School of Earth Sciences The University of QueenslandBrisbaneQueenslandAustralia KDC Consulting 33 Cramond StWitstonQld 4051Australia

The Archean continental crusts account for ca.20% of the present volume,but the thermal history of the Earths＇ mantle suggests much more continental crusts were formed in the early *** the Archean continental crust underwent severe metamorphism,it is important to avoid influence by the later thermal *** carried out a comprehensive geochronological work of Cathodoluminescence（CL） observation and U-Pb dating of zircons from orthogneisses and supracrustal rocks over the Saglek Block to obtain their protolith *** zircons were classified into three domains of core,mantle and rims,and the cores were further classified into three groups of inherited,altered and zoned cores based on the zonation on the CL *** estimated the protolith ages from Pb-Pb ages of the zoned-cores of zircons with low U *** made a detailed sketch of a small outcrop in ***＇s Harbour South（SJHS） area,and classified the orthogneisses and mafic enclaves into seven generations based on the geologic *** first and second generations comprise mafic rocks and lack magmatic *** conducted CL imaging and U-Pb dating of zircons from the third,sixth and seventh generation of the orthogneisses to estimate the protolith ages at 3902 L 25,3892 ± 33 and 3897 ± 33 Ma for each,supporting the presence of the over 3.9 Ca Iqaluk *** geological occurrence that the mafic rocks occur as enclaves within the 3.9 Ga Iqaluk Gneiss indicates that they are the oldest supracrustal rocks in the *** geochronological and geological studies show the Uivak Gneiss is quite varied in lithology and age from 3.6 to 〉3.9 Ga,and tentatively classified into six groups based on their *** oldest Uivak Gneiss components including the Iqaluk Gneiss are present around the SJHS area,and the orthogneisses become young as it is *** lines of evidence of overprinting of younger granitoid on older granitoid in small outcrops and geological-map scale as well as presence of in

关键词： Eoarchean Geochronology Uivak Gneiss Iqaluk Gneiss Continental recycling The oldest rocks

Amount of Calcium Elution and Eroded Lesion Depth in Bovine Enamel Derived from Single Short Time Immersion in Carbonated Soft Drink <i>in Vitro</i>

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Open Journal of Stomatology 2015年第3期5卷 80-86页

作者： Koji Watanabe Toshiko Tanaka kenshi maki Hideaki Nakashima Shigeru Watanabe Division of Pediatric Dentistry Department of Development and Fostering Meikai University School of Dentistry Saitama Japan Division of Surgery Department of Health Promotion Kyushu Dental University Fukuoka Japan Division of Developmental Stomatognathic Function Science Department of Health Promotion Kyushu Dental University Fukuoka Japan

Erosion is one of serious oral health problems among Japanese children. Some dentists argue that brushing just after food/drink intake induces enamel abrasion. Objectives of this study were to evaluate amount of calcium elution from bovine enamel due to single and short immersion into carbonated soft drink, to calculate depth of the eroded lesion, and to determine when to brush teeth after carbonated soft drink intake from the view point of preventing enamel abrasion. Four enamel specimens were made from each of eight bovine teeth. The specimens were covered by quick-cure resin except for enamel surfaces. The four specimens from each bovine tooth were classified into three, six, nine, and 12 minutes immersion (IM3, IM6, IM9, and IM12) groups and immersed separately in five mL of carbonated soft drink. After the immersion, the calcium concentration of the original drink and the drink samples were evaluated using atomic absorption spectrophotometry. The dimension of each enamel specimen was calculated using a planimeter. The amount of eluted calcium per unit area of the enamel specimen into each drink sample was obtained. The depth of the demineralized lesion was obtained by dividing the amount of calcium elution per unit area by the concentration of calcium in enamel and the specific gravity of enamel. The lesion depth of the IM3 group was significantly lower than those in the IM6, IM9, and IM12 groups. The mean lesion depth in the IM12 group which showed the deepest lesion depth was 0.21 μm. As conclusions, the erosive lesion depth due to intake of carbonated soft drink was much shallower than remineralized enamel surface of a white spot lesion which can be repaired in plaque fluid in a short time, suggesting such erosion hardly causes tooth wear, hence it was suggested that brushing teeth just after the intake was recommended.

关键词： Erosion Bovine Enamel Carbonated Soft Drink Calcium

Acid Elution of Aluminum and Calcium from Human Deciduous Enamel in Relation to Dental Caries

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Open Journal of Stomatology 2016年第2期6卷 54-63页

作者： Koji Watanabe Toshiko Tanaka Ayaka Enomoto Katsura Saeki Shigenori Kawagishi Hideaki Nakashima kenshi maki Shigeru Watanabe Division of Pediatric Dentistry Department of Human Development and Fostering Meikai University School of Dentistry Sakado Japan Division of Developmental Stomatognathic Function Science Department of Health Promotion Kyushu Dental University Kitakyushu Japan Division of Surgery Department of Health Promotion Kyushu Dental University Kitakyushu Japan Division of Multidisciplinary Studies Department of Health Promotion Kyushu Dental University Kitakyushu Japan

Although aluminum itself was reported to prevent dental caries, previous in vitro studies reported that the aluminum level in the whole saliva of children was independent of caries prevalence. Purposes of this study were to compare the elution levels of aluminum and calcium from deciduous enamel into acidic artificial saliva, and determine whether the degree of aluminum elution reflects individual caries risk. One hundred and eleven extracted human deciduous teeth were collected. Concentrations of aluminum and calcium eluted from sound regions of enamel into artificial saliva (pH 6.2 or 5.5) were determined using atomic absorption spectrophotometry. One hundred and four and 108 available data samples were obtained for aluminum and calcium evaluation, respectively, and were compared based on the sex, tooth type, caries history, and the number of the donor’s carious teeth at each pH. Calcium elution was not affected by the sex;however, more aluminum was eluted from boys’ than from girls’ teeth at pH 5.5. The aluminum release depended on the tooth type, and was significantly higher in incisors than in molars at a pH of 5.5. In relation to the caries history, aluminum (at pH 5.5) and calcium (at pH 6.2) dissolved more from sound regions of the enamel of caries-experienced teeth than from the enamel of teeth without caries experience. Moreover, aluminum markedly dissolved from enamel in artificial saliva at both pH 6.2 and 5.5 when the donor had more carious teeth, regardless of the presence or absence of caries experience in the sampled teeth. There is a possibility that the rate of aluminum elution from enamel into acidic fluid reflects individual caries sensitivity.

关键词： Aluminum Elution Deciduous Enamel Dental Caries Artificial Saliva

Advantage of Introducing Quantitative Light-Induced Fluorescence in School Dental Checkups

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Health 2018年第8期10卷 1095-1106页

作者： Koji Watanabe Takashi Sasabe Akihiro Nakamura Kosuke Eda Kosuke Tanase Hidefumi Ikeda Naoko Ohata Yukiko Minohara kenshi maki Shigeru Watanabe Division of Developmental Stomatognathic Function Science Department of Health Promotion Kyushu Dental University Kitakyushu Japan Division of Pediatric Dentistry Department of Human Development and Fostering Meikai University School of Dentistry Sakado Japan

Background: Caries detection in school oral examinations insufficient accuracy. Objective: To evaluate advantages of introducing quantitative light-induced fluorescence-digital (QLF-D) in school oral examinations. Methods: Experiment No. 1. Early demineralized lesions in the upper and lower incisors and canines were visually inspected by three dentists and by QLF-D. The numbers of tooth planes with early demineralized lesions were compared between the methods. Experiment No. 2. Approximal demineralized lesions in molars were assessed by visual inspection, x-ray imaging, and QLF-D. The numbers of tooth planes with demineralized lesions were compared among the methods. Experiment No. 3. Plaque distribution was evaluated by QLF-D and a traditional staining method. The ratio of the diameter of plaque to tooth crown in the tooth axis direction in each method was calculated. The results were evaluated by Pearson’s correlation coefficient analysis and Bland-Altman plot. Results: Experiment No. 1. The three dentists found 0.67 tooth planes on average. QLF-D found 22 tooth planes with early demineralized lesions in the same samples. Experiment No. 2. Fourteen approximal tooth planes of molars were found to have demineralized lesions by x-ray imaging. QLF-D detected 71.4% of the tooth planes out of the 14, whereas visual inspection found 7.1%. Experiment No. 3. The Pearson’s correlation coefficient for the evaluations of plaque distribution between the QLF-D and traditional staining methods was 0.77 (P Conclusion: The results support introduction of QLF-D for use in school dental examinations.

关键词： Oral Checkup Early Demineralized Lesion Approximal Demineralized Lesion Quantitative Light-Induced Fluorescence-Digital

Increase in colonic diverticular hemorrhage and confounding factors

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World Journal of Gastrointestinal Pharmacology and Therapeutics 2016年第3期7卷 440-446页

作者： Ken Kinjo Toshiyuki Matsui Takashi Hisabe Hiroshi Ishihara Shinichiro maki Kenta Chuman Akihiro Koga Kensei Ohtsu Noritaka Takatsu Fumihito Hirai kenshi Yao Masakazu Washio Department of Gastroenterology Fukuoka University Chikushi Hospital Department of Community Health and Clinical Epidemiology St.Mary’s College

AIM: To classify changes over time in causes of lower gastrointestinal bleeding(LGIB) and to identify factors associated with changes in the incidence and characteristics of diverticular hemorrhage(DH).METHODS: A total of 1803 patients underwent colonoscopy for overt LGIB at our hospital from 1995 to 2013. Patients were divided into an early group(EG, 1995-2006, n = 828) and a late group(LG, 2007-2013, n = 975), and specific diseases were compared between groups. In addition, antithrombotic drug(ATD) use and nonsteroidal anti-inflammatory drug(NSAID) use were comparedbetween patients with and without DH. RESULTS: Older patients(≥ 70 years old) and those with colonic DH were more frequent in LG than in EG(P < 0.01). Patients using ATDs as well as NSAIDs, male sex, obesity(body mass index ≥ 25 kg/m2), smoking, alcohol drinking, and arteriosclerotic diseases were more frequent in patients with DH than in those without. CONCLUSION: Incidence of colonic DH seems to increase with aging of the population, and factors involved include use of ATDs and NSAIDs, male sex, obesity, smoking, alcohol drinking, and arteriosclerotic disease. These factors are of value in handling DH patients.

关键词： Lower gastrointestinal bleeding Colonic diverticular hemorrhage Increase of incidence Aging