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Rietveld Structure Refinement of Biotite Using Neutron Powder Diffraction (중성자분말회절법을 이용한 흑운모의 Rietveld Structure Refinement)

  • 전철민;김신애;문희수
    • Economic and Environmental Geology
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    • v.34 no.1
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    • pp.1-12
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    • 2001
  • The crystal structure of biotite-1M from Bancroft, Ontario, was determined by Rietveld refinement method using high-resolution neutron powder diffraction data at -26.3$^{\circ}C$, 2$0^{\circ}C$, 30$0^{\circ}C$, $600^{\circ}C$, 90$0^{\circ}C$. The crystal structure has been refined to a R sub(B) of 5.06%-11.9% and S (Goodness of fitness) of 2.97-3.94. The expansion rate of a, b, c unit cell dimensions with elevated temperature linearly increase to $600^{\circ}C$. The expansivity of the c dimension is $1.61{\times}10^{40}C^{-1}$, while $2.73{\times}10^{50}C^{-1}$ and $5.71{\times}10^{-50}C^{-1}$ for the a and b dimensions, respectively. Thus, the volume increase of the unit cell is dominated by expansion of the c axis as increasing temperature. In contrast to the trend, the expansivity of the dimensions is decreased at 90$0^{\circ}C$. It may be attributed to a change in cation size caused by dehydroxylation-oxidation of $Fe^{2+}$ to $Fe^{3+}$ in vacuum condition at such high temperature. The position of H-proton was determined by the refinement of diffraction pattern at low temperature (-2.63$^{\circ}C$). The position is 0.9103${\AA}$ from the O sub(4) location and located at atomic coordinates (x/a=0.138, y/b=0.5, z/c=0.305) with the OH vector almost normal to plane (001). According to the increase of the temperature, $\alpha$* (tetrahedral rotation angle), $t_{oct}$ (octahedral sheet thickness), mean distance increase except 90$0^{\circ}C$ data. But the trend is less clearly relative to unit cell dimension expansion because the expansion is dominant to the interlayer. Also, ${\Psi}$ (octahedral flattening angle) shows no trends as increasing temperature and it may be because the octahedron (M1, M2) is substituted by Mg and Fe.

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Risk Assessment of Arsenic by Human Exposure of Contaminated Soil, Groundwater and Rice Grain (오염된 토양, 지하수 및 쌀의 인체노출에 따른 비소의 위해성 평가)

  • Lee Jin-Soo;Chon Hyo-Taek
    • Economic and Environmental Geology
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    • v.38 no.5 s.174
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    • pp.535-545
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    • 2005
  • Environmental survey from some abandoned metal mine areas was undertaken on to assess the risk of adverse health effects on human exposure to arsenic influenced by past Au-Ag mining activities. Elevated levels of As were found in tailings from the studied mine areas. This high concentration may have a impact on soils and waters around the tailing piles. In order to perform the human risk assessment, chemical analysis data of soils, rice grains and waters fur As have been used. The HQ values fer As via the rice grain and groundwater consumption were significantly higher compared with other exposure pathways in all metal mine areas. However, there were minimal soil and water dermal contact risks. The resulting Hl values of As from the Dongil, Okdong and Hwacheon mine areas were higher than 5.0, and their toxic risk due to drinking water and rice grain was strong in these mine areas. The cancer risk of being exposed to As by the rice grain route from the Dongil, Okdong and Hwacheon mine areas was $5.2\times10^{-4},\;6.0\times10^{-4}\;and\;8.1\times10^{-4}$, respectively. The As cancer risk via the exposure pathway of drinking water from these mine areas exceeded the acceptable risk of 1 in 10,000 fer regulatory purposes. Thus, the daily intakes of groundwater and rice grain by the local residents from the Dongil, Okdong and Hwacheon mine areas can pose a potential health threat if exposed by long-term arsenic exposure.

Characterization of Copper Toxicity Symptoms and Determination of Tissue Critical Concentration for Diagnostic Criteria in Korean Bred Strawberries (국내육성 주요 딸기 품종에서 발생하는 구리(Cu) 과잉 증상 및 영양진단을 위한 식물체 내 한계농도)

  • Choi, Jong Myung;Nam, Min Ho;Lee, Chiwon W.
    • Horticultural Science & Technology
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    • v.30 no.5
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    • pp.477-483
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    • 2012
  • This study was carried out to investigate the influence of copper concentrations in fertilizer solution on the growth of and nutrient uptake by domestically bred strawberries. The characterization of toxicity symptoms as well as tissue analyses based on dry weight of above ground tissue were also conducted to determine the threshold levels in plants when toxicity developed in copper. The dry weights of the above ground tissue were not significantly different among the treatments of 0.25 mM to 1.0 mM in 'Keumhyang' and 'Maehyang' strawberries and that of 0.25 mM to 3.0 mM in 'Seolhyang' strawberry. This indicates that the 'Seolhyang' strawberry is more tolerant to copper toxicity than 'Keumhyang' or 'Maehyang' strawberries. Application of copper at high concentrations resulted in severe toxicity such as death of extensive areas of leaves. The lower leaves became yellow and die rapidly as the symptoms spread up the plants. The leaf blades and petioles died back to the crown and hang on by mechanical attachment. Symptoms of copper toxicity in lower leaves developed as browning on leaf margins and in patches between leaf veins that became necrotic. The elevation of copper concentrations in fertilizer solution did not influence the tissue phosphorus, potassium, calcium, and magnesium contents based on the dry weight of the above ground tissue. The tissue copper contents increased lineally as the copper concentrations in fertilizer solution were elevated. But the tissue iron, manganese and boron contents were not influenced by the concentrations. When the concentration of copper at which growth of a plant is retarded by 10% is regarded as threshold level, the copper contents based on dry weight of above ground plant tissue should be lower than 71.4, 57.9 and 74.8 $mg{\cdot}kg^{-1}$ in 'Keumhyang', 'Maehyang' and 'Seolhyang' strawberries, respectively. The symptom characterization and established threshold level in copper toxicity would help growers to prevent the reduction of crop growth and yield in 'Seolhyang' strawberry cultivation.

A Case of Adult-onset Type II Citrullinemia Confirmed by Mutation of SLC25A13 (SLC25A13 유전자 돌연변이로 확진된 성인형 제 2형 시트룰린혈증 1례)

  • Jeung, Min Sub;Yang, Aram;Kim, Jinsup;Park, Hyung-Doo;Lee, Heon Ju;Jin, Dong-Kyu;Cho, Sung Yoon
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.16 no.1
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    • pp.34-41
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    • 2016
  • Adult-onset type II citrullinemia (CTLN2) is characterized by episodes of neurologic symptoms associated with hyperammonemia leading to disorientation, irritability, seizures, and coma. CTLN2 is distinct from classical citrullinemia, which is caused by a mutation of the argininosuccinic acid synthetase (ASS) gene. The serum citrulline level is elevated, while the activity of ASS in liver tissue is decreased. CTLN2 is known to have a poor prognosis if the proper treatment is not taken. We reported a female aged 37 years who developed recurrent attacks of altered consciousness, aberrant behavior, and vomiting. We initially suspected the patient had CTLN2 because of the signs of hyperammonemic encephalopathy, such as altered mentality, memory disturbance, and aberrant behaviors provoked by exercise-induced stress and excessive intravenous amino acid administration. Through her peculiar diet preferences and laboratory findings that included hyperammonemia and citrullinemia, we diagnosed the patient as CTLN2, and SLC25A13 sequencing revealed known compound heterozygous mutations (IVS11+1G>A, c.674C> A). Her parents were heterozygous carriers, and we identified that her older sister had the same mutations. The older sister had not experienced any episodes of hyperammonemia, but she had peculiar diet preferences. The patient and her sister have been well with conservative management. When considering the clinical course of CTLN2, it was meaningful that the older sister could be diagnosed early in an asymptomatic period and that preemptive treatment was employed. Through this case, CTLN2 should be considered in adults who present symptoms of hyperammonemic encephalopathy without a definite etiology. Because of its rare incidence and similar clinical features, CTLN2 is frequently misdiagnosed as hepatic encephalopathy, and it shows a poor prognosis due to the lack of early diagnosis and proper treatment. A high-carbohydrate diet, which is usually used to treat other urea cycle defects, can also exaggerate the clinical course of CTLN2, so proper metabolic screening tests and genetic studies should be performed.

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Effects of Repeated Immobilization Stress on the Renal Peripheral Benzodiazepine Receptor in Rats (반복적 부동화 스트레스가 흰쥐 신장의 말초성 benzodiazepine 수용체에 미치는 영향)

  • Park Yong Hoon;Moon Han Ku;Shin Son Moon;Lee Eun Ju;Lee Eun Sil;Ha Jeoung-Hee
    • Childhood Kidney Diseases
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    • v.3 no.1
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    • pp.20-26
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    • 1999
  • Purpose : Several modulatory factors for renal peripheral benzodiazepine receptor (PBR) has been reported, but their physiological significance remains elusive. Tissue-specific, stress-induced down-regulation of renal PBR coupled with the pharmacological stimulation of these effects by angiotensin II suggested that physiological significance of renal PBR may be related to the pathophysiology of stress-induced hypertension. The boderline hypertensive rat (BHR) has been used extensively to study the interaction of environmental factors, such as stress and blood pressure. The BHR is the first-generation progeny of a cross between the spontaneously hypertensive rat and the control Wistar-Kyoto rat. The pathogenesis of stress induced hypertension in this model is not demonstrated well. Methods In this study, BHR (male, 150-200 g) and Sprague-Dawley (SD, male, 150-200 g) rats were treated by repeated immobilization to induce anxiety. We used plus-maze performance to observe the level of anxiety by measuring percent open crosses and percent time in open. Results : Percent open crosses and percent time in open in BHR were lower than in SD rats (P<0.05). Receptor densities of renal PBR in BHRs were significantly lower than those of SDs (P<0.05). We also observed that the renal PBR was upregulated in the repeatedly stressed (immobilization, 2 hours daily, for 2 weeks) rats, both in the BHR and SD. However, the density of renal PBR in the stressed BHR was still lower than that of stressed SD. Renal PBR has been suggested to be an important organs which Is responsible for the production of cholesterol-derived products during stress. Conrlusion : From these results, it can be summarized that the lowed density of renal PBR may be involved in the pathogeneis of stress-induced hypertension.

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A Study on the Usefulness of Perfusion MRI in Grading of Gliomas (뇌교종의 악성도 평가에서의 관류자기공명영상의 유용성에 관한 연구)

  • Khang, Hyun-Soo;Kim, Jong-Man;Ko, Shin-Kwan;Moon, Chan-Hong;Yu, In-Kyu;Han, Dong-Kyoon
    • Journal of radiological science and technology
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    • v.32 no.4
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    • pp.461-469
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    • 2009
  • To predict the tumor grading, various imaging modalities have been applied clinically. This study determines clinical usefulness of perfusion MRI, using relative cerebral blood volume in grading of the gliomas. We did a retrospective review of 17 patients (mean age, 57.5 years; 11 male, 6 female) who underwent perfusion MR and conventional MRI, and then correlated pathologically after operation. Statistical analysis of regional cerebral blood volume and relative cerebral blood volume(rCBV) was performed by using softwares such as PAT by SIEMENS and Xmap ver 2.0 developed by ourselves. Six patients out of 13 were low-grade gliomas while eleven patients were the high-grade gliomas. Mean relative CBV (m_rCBV/white matter) in the low-grade gliomas was 1.62, and mean relative CBV(m_rCBV/cortex) was 0.12. In the high-grade gliomas, mean relative CBV(m_rCBV/white matter) and mean relative CBV(m_rCBV/cortex) were 33.53 and 0.96. Mean relative CBV of gliomas were elevated with a statistical difference(P<.05), compared with contralateral white matter(P=.019) or cortex(P=.025). Furthermore mean relative CBV(m_rCBV/white matter) was much higher than mean relative CBV(m_rCBV/cortex). Perfusion MRI using regional cerebral blood volume and rCBV is very useful imaging modality for grading the glioma.

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Effect of Chelated Organic Minerals Liquid Fertilizer on Growth and Fruit Quality in 'Jukhyang' Strawberry (킬레이트 유기 미네랄 액비가 '죽향' 딸기의 생육 및 과실품질에 미치는 영향)

  • Noh, Hye-Ji;Chae, Hyo-Seok;Cho, Hyang-Hyun;Lee, Cheol-Gyu
    • Korean Journal of Organic Agriculture
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    • v.25 no.4
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    • pp.725-736
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    • 2017
  • TThis study investigated the influence of AGH-Ringer (chelated organic minerals liquid fertilizer) on the growth, yield, and fruit quality of 'Jukhyang' strawberry in a hydroponic system. The results revealed that AGH-Ringer group led to significantly higher plant length than that of the control group, and that leaf length and leaf width increased with increasing leaf area. In addition, the fresh and dry weights of leaves and SPAD unit, which measures leaf color also showed a significant increase with AGH-Ringer. However, the length and dry weight of roots did not show significant differences when compared to the control group. In the fruit quality analysis, AGH-Ringer group did not show any difference in fruit length compared to the control group, but it increased both the fruit weight, which, along with the simultaneous increase in fruit width, increased the yield per strawberry. Furthermore, AGH-Ringer group strengthened the red skin color of the fruit, and resulted in significantly greater hardness than that of the control group, but did not have any effect on the soluble solid content and acidity. As shown in the results, the AGH-Ringer group resulted in lesser mineral content and lower to medium EC (electrical conductivity) in comparison to the inorganic mineral hydroponic fertilizer, which was used as a control. However, it increased the leaf growth, fruit weight, and yield, and improved the fruit quality by increasing the soluble solid content in the hydroponic system of 'Jukhyang' strawberry. Therefore, based on this study, AGH-Ringer is thought to be a more effective hydroponic fertilizer than the inorganic mineral hydroponic fertilizer. Moreover, the field experiment demonstrated that AGH-Ringer is a useful hydroponic fertilizer convenient for application in farms. This study also proved that AGH-Ringer is a fertilizer that can promote plant nutrition by controlling the salinity of the soil and facilitating the absorption of necessary minerals in future soil cultivation, thereby providing basic data for organic farming.

Partially purified Toxoplasma gondii antigens by immunoaffinity chromatography (Immunoaffinity chromatography를 이용한 톡소포자충 항원의 부분정제)

  • 안명희;현근희
    • Parasites, Hosts and Diseases
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    • v.35 no.4
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    • pp.251-258
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    • 1997
  • Tachyzoite antigens of Toxoplosnc gondii (RH) were partially purified by immunoaffinity chromatography. The cultivated ToxopLusmc in uiuo (mouse) and in nitro (Hep-2 cell) and peritoneal fluid of T. Bondii infected mice were collected for antigen analy- sis. Tachyzoite antigens collected from infected mouse showed positive bands of 76 kDa, 70 kDa,64 kDa, 53 kDa, 46 kDa, 44 kDa, 41 kDa, 35 kDa, 25 kDa, 18 kDa, and 13 kDa on immunoblot with anti-Toxoplcsmn rabbit sera, and those from infected Hep-2 cells revealed reactive bands of 70 kDa,64 kDa,53 kDa,35 kDa,28 kDa, and 13-10 kDa. After applying to an IgG-Sepharose column, two elusion peaks, E-1 and I-2 fractions, were obtained from both soluble antigen of T. gondii and the peritoneal fluid of infected mice, respectively. Immunoblots of soluble antigen with immunized rabbit sera revealed positive bands of 97 kDa, 63 kDa, 53 kDa and 35 kDa from I-1 fraction and 53 kDa and 35 kDa from I-2. In the case of the eluted peaks from mice peritoneal fluid, E-1 showed protein bands of 84 kDa,76 kDa,53 kDa and 29 kDa bands and 53 kDa and 45 kDa from I-2 on immunoblots. Serum IgG antibody titer of mice immunized with T gonnii tachyzoites was increased on 1 week after booster immunization when analysed by ELISA using crude antigen, while it was elevated on 3 weeks after booster immunization by ELISA using puri- fied antigen.

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Ginsenoside R $b_2$ and Rc Formation and Inorganic Elements Uptake in Ginseng Hairy Roots Cultures (인삼모상근 배양에서 Ginsenoside R $b_2$ 및 Rc 생성과 무기이온 흡수)

  • 양덕조;윤길영;최규명;유승희
    • Korean Journal of Plant Tissue Culture
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    • v.27 no.6
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    • pp.461-468
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    • 2000
  • For the enhancement of ginsenoside production in hairy roots cultures of Panax ginseng, the uptake rate of inorganic elements and ginsenoside contents were investigated by different concentrations of about phosphorus (P $O_{4}$$^{[-10]}$ ) and nitrogen (N $H_{4}$$^{+}$, N $O_{3}$$^{[-10]}$ ) sources. According to increased phosphorus and nitrogen sources, the uptake rate of $Mg^{2+}$ and F $e^{2+}$ in ginseng hairy roots were significantly increased. The uptake rate of F $e^{2+}$ in 5.15 mM N $H_{4}$$^{+}$ was higher at 47.5% than that in 20.6 mM, whereas that of C $u^{2+}$ in 10.3 mM were higher at 123.1% than that in 41.2 mM. These results indicated that phosphorus and nitrogen sources act not only elevated growth of hairy roots but also the uptake-enhancement of the irons and other ions. The optimum concentration of phosphorus and nitrogen sources for the contents of free sugars were different to kinds of free sugars. The optimum concentration of phosphorus and nitrogen sources for the ginsenoside formation in ginseng hairy roots cultures were highest at the most low concentration of all. The contents of ginsenoside-R $b_2$and -Rc in 0.31 mM P $O_{4}$$^{[-10]}$ were increased to 44.7% and 29.9% than that in 0.62 mM P $O_{4}$$^{[-10]}$ , respectively. The contents of ginsenoside-R $b_2$ and -Rc in 5.15 mM N $H_{4}$$^{+}$ were increased to 21.7% and 31.9% than that in 10.30 mM N $H_{4}$$^{+}$, respectively. The contents of ginsenoside-R $b_2$and -Rc in 4.7 mn N $O_{3}$$^{[-10]}$ were also increased to 17.6% and 25.5% than that in 9.4 mM N $O_{3}$$^{[-10]}$ , respectively. These results indicate that enhancement of the ginsenoside formation in ginseng hairy roots was feasible by new medium modulation of concentration of phosphorus and nitrogen sources.rogen sources.

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Clinical Features of Dietary Protein Induced Proctocolitis (식이 단백 유발 직결장염의 임상적 고찰)

  • Im, Sun Ju;Kim, Seong Heon;Bae, Sang Nam;Park, Jae Hong
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.8 no.2
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    • pp.157-163
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    • 2005
  • Purpose: Dietary protein induced proctocolitis (DPIPC) can be considered as a cause of rectal bleeding or blood streaked stool in otherwise healthy-looking infants in the first several months of life. Failure to appreciate this entity may lead to inappropriate diagnostic or therapeutic intervention. This study aimed to ascertain the clinical features, treatment and prognosis of DPIPC. Methods: We reviewed 13 infants retrospectively, presented with bloody stool in early infancy. They were diagnosed as DPIPC clinically in Pusan National University Hospital from May 2002 to June 2004. Results: Seven males and six females were included. The mean age at onset of bleeding was $96.8{\pm}58.8days$. The mean frequency of hematochezia was $2.6{\pm}2.5$ times a day. Duration from onset of symptom to diagnosis was $35.5{\pm}55.0days$ and duration from onset of symptom to resolution of bleeding was $58.7{\pm}67.0days$. Nine (69.2%) were exclusively breast-fed infants and two (15.4%) were formula-fed infants. All but one infant did not have family history of other allergic diseases. A dietary history of ingestion of cow's milk, nut or shellfish was present in three mothers. Peripheral eosinophil count was normal to slightly elevated (total WBC count $10,555{\pm}3,145/mm^3$, relative eosinophil count $6.3{\pm}3.0%$, absolute eosinophil count $659.0{\pm}532.2/mm^3$). Sigmoidoscopy revealed lymphonodular hyperplasia with surrounding hemorrhagic spots in the rectosigmoid colon in 6 infants. Histopathologic finding of colonic biopsies in 5 infants showed chronic inflammation with lymphoid follicular hyperplasia (5 infants), crypt abscess (3 infants), or mild infiltration of eosinophils (less than 20/high power field) in the lamina propria. Spontaneous resolution of rectal bleeding occurred in all infants without dietary change or medicine. Conclusion: Most infants with DPIPC experience a very benign course and have spontaneous resolution of rectal bleeding without changes in the mother's diet. In the case of strong evidence for DPIPC we suggest deferring further invasive investigation and continuing breast feeding.

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