• Title/Summary/Keyword: fluoride migration

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Fluoride Migration of Frozen Antarctic Krill According to Thawing Methods (해동방법에 의한 냉동크릴의 불소이동)

  • Kim, Kil-Hwan;Kim, Dong-Man;Kim, Young-Ho;Yoon, Hye-Hyun
    • Korean Journal of Food Science and Technology
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    • v.22 no.2
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    • pp.168-171
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    • 1990
  • This study was purposed to elucidate the migration phenomenon of fluoride from the chitinous sections into the muscle flesh of the frozen krill during thawing. The fluoride content ratio between chitinous sections and muscle flesh in the frozen krill was 94.8 : 5.2. Among the several thawing methods used, migration velocity of fluoride was the highest in the krill thawed with microwave and the lowest in the krill thawed at low temperature $(4^{\circ}C)$. The migrated amount of fluoride after thawing was various depended upon the thawing methods, and the increased amount during thawing was 2-5 times higher than Initial amount before thawing.

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Geochemical Investigation of Fluoride Migration in the Soil Affected by an Accidental Hydrofluoric Acid Leakage (불산 누출사고 지역 토양수의 지구화학적 특성을 통한 불소 거동 및 확산 잠재성 연구)

  • Kwon, Eunhye;Lee, Hyun A;Kim, Doyoung;Lee, Junseok;Lee, Sanghoon;Yoon, Hye-On
    • Journal of Soil and Groundwater Environment
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    • v.20 no.3
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    • pp.65-73
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    • 2015
  • The hydrofluoric acid (HF) leakage accident occurred on September 2012 in Gumi, Korea affected the surrounding soils and plants. In this study, we investigated fluoride migration in Gumi area through geochemical properties of soil-liquid phase (pore water F and water-soluble F). The concentrations of porewater F and water-soluble F were obtained from N.D (Not detected) to 9.79 mg/L and from 0.001 to 21.4 mg/L, respectively. F in pore water seemed to be affected by artificial and natural origin, and PHREEQC results implied that fluorite is F control factor. F concentrations of soil and soil-liquid phase did not exceed concern level of regulatory criteria and showed similar trends compared by previous studies. Therefore, F contents remained in the soil and soil-liquid phase were considered to be not affected by HF leakage accident.

THE EFFECT OF TWO KINDS OF PERIODONTAL LIGAMENT MANAGEMENT UPON PERIODONTAL HEALING AND ROOT RESORPTION AFTER REPLANTATION IN RATS (쥐치아재식 모델에서 치주인대의 처리방법에 따른 치주조직의 치유와 치근흡수에 관한 연구)

  • Kwon, So-Ran;Kum, Kee-Yeon;Lee, Seung-Jong
    • Restorative Dentistry and Endodontics
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    • v.25 no.3
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    • pp.338-358
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    • 2000
  • The effect of bench drying or removal of the periodontal ligament with NaOCl upon periodontal healing and root resorption after replantation of molars was studied in rats. A total of 40 Sprague-Dawley female rats were used and fed a powdered purina rat chow diet containing 0.4% beta-aminoproprionitrile. The maxillary first molars were extracted and the periodontal ligaments were removed either by bench drying for 15 minutes or by immersion in 2.5% NaOCl solution. The rats were sacrificed at 5, 10, and 21 days by heart infusion. In order to observe the effect of 0.5% stannous fluoride, $10^{-4}M$, $10^{-2}M$, and 1M etidronate disodium on the early stage of periodontal healing, the periodontal ligament was removed with 2.5% NaOCl followed by immersion of the molar in the respective solutions for 5 minutes. The rats were sacrificed after 10 days and the following results were obtained. 1. The removal of the periodontal ligament with 2.5% NaOCl seemed to be more effective than bench drying, since the resorption area in the NaOCl treated group showed a gradual increase whereas a decline in resorption area from 5 days to 21 days was observed in the bench dried group. 2. The application of 0.5% stannous fluoride seemed to enhance the periodontal ligament attachment and active migration of fibroblasts could be observed. 3. The application of $10^{-4}M$, $10^{-2}M$, and 1M etidronate disodium led to a good periodontal ligament attachment. No evident areas of root resorption were found. 4. The use of ${\beta}$-APN made it possible to extract the maxillary first molar with all five roots intact.

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The ADAM15 ectodomain is shed from secretory exosomes

  • Lee, Hee Doo;Kim, Yeon Hyang;Koo, Bon-Hun;Kim, Doo-Sik
    • BMB Reports
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    • v.48 no.5
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    • pp.277-282
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    • 2015
  • We demonstrated previously that a disintegrin and metalloproteinase 15 (ADAM15) is released into the extracellular space as an exosomal component, and that ADAM15-rich exosomes have tumor suppressive functions. However, the suppressive mechanism of ADAM15-rich exosomes remains unclear. In this study, we show that the ADAM15 ectodomain is cleaved from released exosomes. This shedding process of the ADAM15 ectodomain was dramatically enhanced in conditioned ovarian cancer cell medium. Proteolytic cleavage was completely blocked by phenylmethylsulfonyl fluoride, indicating that a serine protease is responsible for exosomal ADAM15 shedding. Experimental evidence indicates that the ADAM15 ectodomain itself has comparable functions with those of ADAM15-rich exosomes, which effectively inhibit vitronectininduced cancer cell migration and activation of the MEK/extracellular regulated kinase signaling pathway. We present a tumor suppressive mechanism for ADAM15 exosomes and provide insight into the functional significance of exosomes that generate tumor-inhibitory factors. [BMB Reports 2015; 48(5): 277-282]