• Title/Summary/Keyword: AM

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Determination of $^{241}$Am and $^{241}$Cm in Radwaste Samples (방사성폐기물 시료 중 $\^{241}$Am과 $\^{244}$Cm의 정량)

  • Joe Kih Soo;Kim Tae Hyun;Jeon Young Shin;Jee Kwsng Yong;Kim Won Ho
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.3 no.1
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    • pp.1-7
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    • 2005
  • Anion exchange chromatography and HDEHP extraction chromatography using DTPA-lactic acid as an eluent were applied in series for the separation of $^{241}$Am and $^{244}$Cm in radwaste samples. The separated elements were determined by electrodeposition at the sodium hydrogen sulfate-sodium sulfate buffer solution followed by alpha-spectrometry. The recovery yields of $^{241}$Am and $^{244}$Cm were 85.2$\pm$$15.3\%$, respectively, from the synthetic solution of spent nuclear fuel sample. The amounts of 241Am and 2440m determined in radwaste sample solutions of condensate bottoms were at the range of 1.5-1.9 Bq/g and -1.7 Bq/g, respectively.

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A Comparison of Lyophilized Amniotic Membrane with Cryopreserved Amniotic Membrane for the Reconstruction of Rabbit Corneal Epithelium

  • Ahn Jae-Il;Jang In-Keun;Lee Doo-Hoon;Seo Young-Kwon;Yoon Hee-Hoon;Shin Youn-Ho;Kim Jae-Chan;Song Kye-Yong;Lee Hee-Gu;Yang Eun-Kyung;Kim Ki-Ho;Park Jung-Keung
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.10 no.3
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    • pp.262-269
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    • 2005
  • Many researchers have employed cryopreserved amniotic membrane (CAM) in the treatment of a severely damaged cornea, using corneal epithelial cells cultured on an amniotic membrane (AM). In this study, two Teflon rings were made for culturing the cells on the LAM and CAM, and were then used to support the AM, which is referred to in this paper as an Ahn's AM supporter. The primary corneal epithelial cells were obtained from the limbus, using an ex-plantation method. The corneal epithelium could be reconstructed by culturing the third­passage corneal epithelial cells on the AM. A lyophilized amniotic membrane (LAM) has a higher rate of graft take, a longer shelf life, is easier to store, and safer, due to gamma irradiation, than a (AM. The corneal epithelium reconstructed on the LAM and (AM, supported by the two­Teflon rings, was similar to normal corneal epithelium. However, the advantages of the LAM over that of the (AM make the former more useful. The reconstruction model of the corneal epithelium, using AM, is considered as a good in vitro model for transplantation of cornel epithelium into patients with a severely damaged cornea.

Platelet-Activating Factor Enhances Interleukin-1 Activity by Alveolar Macrophages : Inhibition by PAF Specific Receptor Antagonists

  • Lee, Ji-Hee
    • The Korean Journal of Physiology and Pharmacology
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    • v.1 no.2
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    • pp.201-208
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    • 1997
  • It is becoming increasingly clear that the inflammatory reaction can be ascribed to a complex array of mediators generated and released from activated phagocytes. In this study, the effect of PAF on interleukin-1(IL-1) activity by rat alveolar macrophages(AM) was examined using thymocyte proliferation assay in the supernate of sample obtained after 24 hr culture. When AM were cultured with PAF alone, no change in IL-1 activity was observed. However, the combined addition of PAF and muramyl dipeptide(MDP) or lipopolysaccharide(LPS) to AM cultures markedly enhanced IL-1 activity by 2-3 fold compared with AM cultures with the stimulant alone in a concentration dependent fashion. The peack effect was found at $10^{-8}$ M PAF with MDP and $10^{-14}$ M PAF with LPS. the effect of PAF was also tested in silica, toxic respirable dust, -added AM cultures as well as in the cultures containing bacterial compounds. Although silica did not stimulate the IL-1 activity, PAF could enhance IL-1 activity by 2 fold above the value of the silica-treated AM cultures with the peak response at $10^{-12}$ M PAF. Optimal enhancement of IL-1 activity occured when MDP and PAF were present together at the initiation of the 24 hr AM cultures. Additionaly, the biologically inactive precursor/metabolite of PAF, lyso-PAF failed to induce enhancement of IL-1 activity. When the specific, but structurally different PAF receptor antagonists, BN 52021($10^{-5}$ M) and CV 3988($10^{-5}$ M) was treated 15 min before addition of PAF($10^{-8}$ M) and MDP$(10\;{\mu}g/ml)$ to the AM cultures, it markedly inhibited the enhancement of IL-1 activity induced by PAF. The effects of these PAF antagonists were also observed in LPS$(10\;{\mu}g/ml)$-stimulated cells. Collectively, these data suggest that PAF enhances IL-1 activity by interaction with a specific receptor.

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The Effect of clinical Experience for Psychiatric Nursing on Urinary $Na^+$, $Cl^-$, $K^+$, $Ca^{++}$ of the Student (간호대학생의 정신간호학 실습이 요중 $Na^+$, $Cl^-$, $K^+$, $Ca^{++}$에 미치는 영향)

  • Na, Hyun-Ju;Han, You-Jeong
    • Journal of Korean Biological Nursing Science
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    • v.3 no.2
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    • pp.51-61
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    • 2001
  • This study was done to investigate the effect of the first experience of the clinical experience for psychiatric nursing on urinary $Na^+$, $Cl^-$, $K^+$, $Ca^{++}$ of the nursing students. We analyzed the urine of 36 students on curriculum who were students of D college in K city. The data were analyzed with SAS Statistical analysis was performed by using paired t-test, GLM. The second day group increased 18.56 at 8AM, 31.90 at 4PM in case of $Na^+$(p=0.004). The second day group increased 27.61 at 8AM, 45.53 at 4PM in a case of $Cl^-$(p=0.009). The first day group increased 2.62 at 8AM, 7.09 at 4PM in case of $K^+$(p=0.018). The second day group increased 3.69 at 8AM, 5.19 at 4PM in a case of $K^+$(p=0.013). The second day group increased 20.65 at 8AM, 14.07 at 4PM in a case of $Ca^{++}$(p=0.033). There was a significant difference in $Na^+$ according to group at 8AM(F=4.17, p=0.024) and 4PM(F=3.58, p=0.040). There was a significant difference in $Cl^-$ according to group at 8AM(F=4.38, p=0.020) and 4PM(F=6.29, p=0.003). There was a significant difference in $K^+$ according to group at 8AM(F=5.03, p=0.012). In conclusion, $Na^+$, $Cl^-$, $K^+$, $Ca^{++}$ may be used as a indicator of the amount of stress to improve the educational environment for the students.

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Biomonitoring of Metal Exposure During Additive Manufacturing (3D Printing)

  • Ljunggren, Stefan A.;Karlsson, Helen;Stahlbom, Bengt;Krapi, Blerim;Fornander, Louise;Karlsson, Lovisa E.;Bergstrom, Bernt;Nordenberg, Eva;Ervik, Torunn K.;Graff, Pal
    • Safety and Health at Work
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    • v.10 no.4
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    • pp.518-526
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    • 2019
  • Background: Additive manufacturing (AM) is a rapidly expanding new technology involving challenges to occupational health. Here, metal exposure in an AM facility with large-scale metallic component production was investigated during two consecutive years with preventive actions in between. Methods: Gravimetric analyzes measured airborne particle concentrations, and filters were analyzed for metal content. In addition, concentrations of airborne particles <300 nm were investigated. Particles from recycled powder were characterized. Biomonitoring of urine and dermal contamination among AM operators, office personnel, and welders was performed. Results: Total and inhalable dust levels were almost all below occupational exposure limits, but inductively coupled plasma mass spectrometry showed that AM operators had a significant increase in cobalt exposure compared with welders. Airborne particle concentrations (<300 nm) showed transient peaks in the AM facility but were lower than those of the welding facility. Particle characterization of recycled powder showed fragmentation and condensates enriched in volatile metals. Biomonitoring showed a nonsignificant increase in the level of metals in urine in AM operators. Dermal cobalt and a trend for increasing urine metals during Workweek Year 1, but not in Year 2, indicated reduced exposure after preventive actions. Conclusion: Gravimetric analyses showed low total and inhalable dust exposure in AM operators. However, transient emission of smaller particles constitutes exposure risks. Preventive actions implemented by the company reduced the workers' metal exposure despite unchanged emissions of particles, indicating a need for careful design and regulation of the AM environments. It also emphasizes the need for relevant exposure markers and biomonitoring of health risks.

CO-SEPARATION OF Am AND RARE EARTH ELEMENTS FROM A HIGHLY ACIDIC RADWASTE SOLUTION BY A SOLVENT EXTRACTION WITH (DIMETHYLDIBUTYL TETRADECYLMALONAMIDE-DIHEXYLOCTANAMIDE)/N-DODECANE

  • Lee, Eil-Hee;Lim, Jae-Gwan;Chung, Dong-Yong;Yoo, Jae-Hyung;Kim, kwang-Wook
    • Nuclear Engineering and Technology
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    • v.41 no.3
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    • pp.319-326
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    • 2009
  • This study was carried out to investigate the high-acidity co-separation of Am and RE from a simulated radwaste solution by a solvent extraction using a mixture of Dimethyldibutyltetradecylmalonamide (DMDBTDMA, as an extractant) and dihexyl octanamide (DHOA, as a phase modifier) diluted with n-dodecane (NDD). All the experiments were conducted as a batch type. First, the environmentally friendly DMDBTDMA and DHOA composed of only CHON atoms were self-synthesized. Then, the conditions for the prevention of a third phase, generated in the organic phase were examined. In addition, the effects of the concentration of nitric acid, DHOA, oxalic acid and $H_2O_2$ on the co-extraction of Am and RE were elucidated. Consequently, the optimum condition of (0.5M DMDBTDMA+0.5M DHOA)/NDD-0.3M $C_2H_2O_4-4.5M$ $HNO_3$ and O/A=2 was obtained through experimental work. Under this condition, the extraction yields were found to be about 80% for Am, more than 70% for RE such as La, Eu, Nd, Ce, etc., 3% for Cs and Sr, 69% for Fe and less than 11% for Mo and Ru. For the co-extraction of Am and RE, Fe should be removed in advance or prevented from a co-extraction with Am by controlling the different extraction rates of Am and Fe. About 95% of the Am and RE in the organic phase were stripped using a 0.5M $HNO_3$.

A Performance Analysis of AM-SCS-MMA Adaptive Equalization Algorithm based on the Minimum Disturbance Technique (Minimum Disturbance 기법을 적용한 AM-SCS-MMA 적응 등화 알고리즘의 성능 해석)

  • Lim, Seung-Gag
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.3
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    • pp.81-87
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    • 2016
  • This paper analysis the AM-SCS-MMA (Adaptive Modulus-Soft Constraint Satisfaction-MMA) based on the adaptive modulus and minimus-disturbance technique in order to improve the stability and robustness in low signal to noise power of current MMA adaptive equalization algorithm. In AM-SCS-MMA, it updates the filter coefficient applying the adaptive modulus and minimum-disturbance technique of deterministic optimization problem instead of LMS or gradient descend algorithm for obtain the minimize the cost function of adaptive equalization. It is possible to improve the equalizer filter stability, robustness to the various noise characteristic and simultaneous reducing the intersymbol interference due to the amplitude and phase distortion occurred at channel. The computer simulation were performed for confirming the improved performance of SCS-MMA. For these, the output signal constellation of equalizer, residual isi, MSE, EMSE (Excess MSE) which means the channel traking capability and SER which means the robustness were applied. As a result of computer simulation, the AM-SCS-MMA have slow convergence time and less residual quantities after steady state, more good robustness in the poor signal to noise ratio, but poor in channel tracking capabilities was confirmed than MMA.

Evaluation of an Amniotic Membrane-Collagen Dermal Substitute in the Management of Full-Thickness Skin Defects in a Pig

  • Kim, Hyunji;Son, Daegu;Choi, Tae Hyun;Jung, Samhyun;Kwon, Sunyoung;Kim, Junhyung;Han, Kihwan
    • Archives of Plastic Surgery
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    • v.40 no.1
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    • pp.11-18
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    • 2013
  • Background To minimize the inflammatory reaction and improve healing, a new modified dermal substitute composed of an atelocollagen, chondroitin-6-sulfate, and amniotic membrane (AM) was applied to full-thickness skin defects in a pig. Atelocollagen was extracted from bovine skin, and two modified dermal substitutes were generated according to the cross-linking type. Methods The AM-collagen dermal substitutes were characterized and compared with currently used dermal substitutes in a pig skin defect model. There were five experimental groups: dehydrothermal (DHT) cross-linking atelocollagen with the AM on the top (AM-DHT), DHT and chemical cross-linking atelocollagen with the AM on the top (AM-DHT/chemical), Terudermis, Integra, and AlloDerm. After $3{\times}3cm$ full-thickness skin defects on the back of a pig were created, each dermal substitutes dermal substitutes was randomly grafted on the defects. Two weeks after grafting, autologous partial-thickness skin was over-grafted on the neodermis. The take rate of the dermal substitutes, skin, and histological sections were all assessed at 1, 2, and 4 weeks postoperatively. Results More rapid healing and a higher take rate were evident in the AM-DHT and Terudermis groups. Histological examination revealed fewer inflammatory cells and more fibroblast hyperplasia in these two groups. Four weeks after surgery, the amount of newly formed collagen was significantly more appropriate in the AM-DHT group. Conclusions These observations provide supporting evidence that a newly developed amniotic-collagen dermal substitute may inhibit inflammatory reactions and promote wound healing.

A Literature Study on the Application of Sa-am Acupuncture for the Treatment of Stroke (중풍(中風)에 대한 사암침법(舍岩鍼法)의 운용(運用)에 관한 문헌(文獻) 연구 - ${\ll}$사암침구정전(舍岩鍼灸正傳)${\gg}$${\ll}$동의보감(東醫寶鑑)${\gg}$${\ll}$침구대성(鍼灸大成)${\gg}$과의 비교연구 -)

  • Lee, Jung-Tae;Yim, Yun-Kyoung
    • Journal of Acupuncture Research
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    • v.23 no.5
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    • pp.115-125
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    • 2006
  • Objectives & methods : This study aimed to investigate and compare the traditional acupuncture treatment and Sa-am acupuncture treatment of stroke. We investigated ${\ll}$Sa-am chimgujeongjeon(舍岩鍼灸正傳)${\gg}$ for Sa-am acupuncture treatment, and ${\ll}$Dongeuibogam(東醫寶鑑)${\gg}$ and ${\ll}$Chimgudaesung (鍼灸大成)${\gg}$ for traditional acupuncture treatment. Results & Conclusion : 1. In the traditional acupuncture treatment, acupoints on CV, GV, GB, LI, ST meridians to remove pathogens such as fire, damp, phlegm, blood stagnation and Ashi points (nearby points) are often used rather than acupoints according to the diagnosis of excess & deficiency in organs and meridians. 2. In ${\ll}$Sa-am chimgujungjeon(舍岩鍼灸正傳)${\gg}$, symptoms of stroke are classified into 21 and each symptoms are analyzed according to the diagnosis of excess & deficiency of organs and meridians, consequently treated using tonification & sedation of corresponding meridians. 3. For the treatment of stroke in ${\ll}$Sa-am chimgujungjeon(舍岩鍼灸正傳)${\gg}$, tonification & sedation of the acupoints on related meridian is often omitted, using only the acupoints on targeted meridian. 4. In ${\ll}$Sa-am chimgujungjeon(舍岩鍼灸正傳)${\gg}$, empirical points are preferably used for the treatment of stroke.

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Growth Response and Arsenic Uptake of White Clover (Trifolium repens) and Evening Primrose(Oenothera odorata) Colonized with Arbuscular Mycorrhizal Fungi in Arsenic-Contaminated Soil

  • Kim, Dae-Yeon;Lee, Yun-Jeong;Lee, Jong-Keun;Koo, Na-Min;Kim, Jeong-Gyu
    • Korean Journal of Environmental Agriculture
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    • v.27 no.1
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    • pp.50-59
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    • 2008
  • A greenhouse experiment was conducted to investigate the role of the arbuscular mycorrhizal(AM) fungus, Glomus mosseae(BEG 107) in enhancing growth and arsenic(As) and phosphorus(P) uptake of white clover(Trifolium repens) and evening primrose(Oenothera odorata) in soil collected from a gold mine having concentrations of 381.6 mg total As $kg^{-1}$ and 20.5 mg available As $kg^{-1}$. Trifolium repens and O. odorata are widely distributed on abandoned metalliferous mines in Korea. The percent root colonization by the AM fungus was 55.9% and 62.3% in T. repens and O. odorata, respectively, whereas no root colonization was detected in control plants grown in a sterile medium. The shoot dry weight of T. repens and O. odorata was increased by 323 and 117% in the AM plants compared to non-mycorrhizal(NAM) plants, respectively. The root dry weight increased up to 24% in T. repens and 70% in O. odorata following AM colonization compared to control plants. Mycorrhizal colonization increased the accumulation of As in the root tissues of T. repens and O. odorata by 99.7 and 91.7% compared to the NAM plants, respectively. The total uptake of P following AM colonization increased by 50% in T. repens and 70% in O. odorata, whereas the P concentration was higher in NAM plants than in the AM plants. Colonization with AM fungi increased the As resistance of the host plants to As toxicity by augmenting the yield of dry matter and increasing the total P uptake. Hence, the application of an AM fungus can effectively improve the phytoremediation capability of T. repens and O. odorata in As-contaminated soil.