• Title/Summary/Keyword: MgB2

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Investigation of Unintentionally Hazardous Substance in Commercial Herbs for Food and Medicine (유통 식약공용농산물 중 비의도적 유해물질 오염도 조사)

  • Seo, Mi-Young;Kim, Myung-Gil;Kim, Jae-Kwan;Jang, Mi-Kyung;Lee, Yu-Na;Ku, Eun-Jung;Park, Kwang-Hee;Yoon, Mi-Hye
    • Journal of Food Hygiene and Safety
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    • v.33 no.6
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    • pp.453-459
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    • 2018
  • This study was performed to investigate the contamination levels of heavy metals (such as lead, cadmium, arsenic and mercury) and aflatoxin (such as $B_1$, $B_2$, $G_1$ and $G_2$) in commercial herbs for food and medicine. The concentrations of the heavy metals were measured by the ICP-MS and a mercury analyzer. The aflatoxins were analyzed by a HPLC-florescence coupled with photochemical derivatization. The detection ranges of the lead, cadmium, arsenic and mercury were found to be 0.006~4.088 mg/kg, 0.002~2.150 mg/kg, ND~0.610 mg/kg and ND~0.0139 mg/kg respectively. Among the total samples, the 3 samples (2.6%) were not suitable for the specification of cadmium by the MFDS (Ministry of Food and Drug Safety). The 13 samples of the total 117 samples were aflatoxin positive (11.1%). The amount of aflatoxin $G_1$ was $0.7834{\mu}g/kg$ in the Puerariae Radix and aflatoxin $G_2$ were $0.3517{\mu}g/kg$, $0.4881{\mu}g/kg$ in two samples of the Glycyrrhizae Radix et Rhizoma, respectively. The aflatoxins $B_2$ and $G_1$ were simultaneously detected in the 10 Angelicae Gigantis Radix. The detection ranges of aflatoxins $B_2$ and $G_1$ were $0.2324{\sim}1.0358{\mu}g/kg$ and $0.7552{\sim}1.6545{\mu}g/kg$ respectively in Angelicae Gigantis Radix. The results of the current study suggest that continuous monitoring is needed for the proactive management of commercial herbs for food and medicine safety.

Characteristics of Mixed Tea Prepared with Several Herbs Cultivated in Korea (한국산 허브를 이용한 혼합 침출차 가공특성)

  • 주선종;최금주;김기식;박성규;김태수;오문헌;이상수;고재원
    • Food Science and Preservation
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    • v.9 no.4
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    • pp.400-405
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    • 2002
  • Herbs are widely used as a source of tea and otherwise such as botanical medicine, essential oil for perfumes, cosmetics, and food spices. This study was carried out to investigate the characteristics of herb tea prepared with lavender, rosemary, mint, thyme and sage cultivated in korea. Approximate composition were as follows : crude protein 1.4∼17.5%, crude fat 6.1∼15.8%, sugars 43.5∼61s%, crude ash 7.7∼10.7%. Minerals contents of Ca ranged 707∼1763mg%, P 234 ∼513mg%, K 2,391∼3,430mg%, and Mg 361∼573mg%. Vitamins were $\beta$ -Carotene 6.9∼27.7mg%, B$_1$, 0.34∼0.62mg%, B$_2$1.37 ∼2.52mg%, niacin 5.3∼8.8mg%, and C 102∼111mg%. The changes of chromaticity a and b, pH, and sugar content of the herb tea at the different temperatures were decreased 80$\^{C}$ and 100$\^{C}$ in comparison to 60$\^{C}$ but increased chromaticity L. In the result of sensory test of the processed herb tea was more preferred than the market goods.

Antimicrobial Activity of Extract from Gall-nut and Red-grape Husk (오배자와 포도 껍질 추출물의 항균 활성에 관한 연구)

  • 이만종;김관필;김성호;정낙현;임무현
    • The Korean Journal of Food And Nutrition
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    • v.10 no.2
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    • pp.174-179
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    • 1997
  • The antimicrobial and GTase(Glucosyltransferase) inhibition activity were investigated for solvent fractions of Gall-nut, variety of fork drugs and Red-grape husk water extracts. Among them, Gall-nut and Red-grape husk water extracts were selected for the powerful antimicrobial and GTase inhibition activity. The methanol fractions of Gall-nut and Red-grape husk were showed very powerful antimicrobial activity on both B. subtilis and E. coli. The MIC(Minimum Inhibitory Concentration) of gall-nut methanol fraction were 1.0mg/ml for B. subtilis and 3.0mg/ml for E. coli. Red-grape husk were 2.0mg/ml for B. subtilis and 3.0mg/ml for E. coli. The methanol fractions of Gall-nut and Red-grape husk were showed very powerful Gtase inhibition activity. The concentrations of these fractions for 80% inhibition of GTase activity were 1.08$\times$10-3mg/ml and 1.08$\times$10-2mg/ml, respectively. The principal compound for the antimicrobial and GTase inhibition activity in tese extracts seems to be polyphenol derivatives.

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Studies on the Chemical Synthesis of Aflatoxin-DNA Adduct (Aflatoxin-DNA Adduct의 화학합성에 관한 연구)

  • Choi, Sang-Kyung;Kim, Sung-Young;Kang, Jin-Soon;Chung, Duck-Hwa
    • Korean Journal of Food Science and Technology
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    • v.24 no.4
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    • pp.367-370
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    • 1992
  • Aflatoxins are highly carcinogenic agents consistantly found as contaminants in human food supplies in many areas of the world and epidemiologically linked to incidence of human liver cancer. To examine the carcinogenic action of aflatoxin $B_1$, aflatoxin $B_1-DNA$ adducts were chemically synhtesized with the reaction of 20 mg calf thymus DNA, and 8 mg standard aflatoxin $B_1$. Since DNA molecule was too large for analysis, it was fragmented by acid hydrolysis and heat. The fragmented aflatoxin $B_1-DNA$ adducts were selectively concentrated by immunoaffinity column procedure and confirmed by HPLC method. The main component was aflatoxin $B_1-guanine$ adduct, which was quantatively measured as 5.2 mg aflatoxin $B_1$.

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Chemical Components of Gastrodia elata Blume Powder (천마 분말의 화학적 성분)

  • Kim, Hyeon-Ju;Chung, Shin-Kyo;Moon, Kwang-Deog
    • Food Science and Preservation
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    • v.7 no.3
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    • pp.278-284
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    • 2000
  • The chemical components in freeze dried Korean Gastrodia elata blume powder were analyzed. The proximate composition was composed of moisture(2.12%), crude protein (4.41%), crude fat(1.20%), crude ash(2.25%), crude fiber(4.60%) and N-free extract(85.15%). Free sugar was composed of glucose(1,314mg%), sucrose(1,081mg%) and fructose(869mg%). Total organic acid content was 2,095mg% and composed of succinic acid(1,238mg%), citric acid, malic acid, oxalic acid and fumaric acid in the order. Among the 11 fatty acids detected, linoleic acid was the most predominant one and unsaturated fatty acid was 80.55 area percent. 18 and 39 amino acids were detected from total and free amino acid, respectively. Arginine, asparagine, proline and sarcosine were the major components of free amino acid. The content of crude saponin and total phenol were 3,768mg% and 821mg%, respectively. Ascorbic acid(6.4mg%), vitamin B1(1.2mg%), vitamin B2(1.7mg%) and niacinamide(0.2m%) were detected as soluble vitamins of the powder. The content of vitamin A and vitamin E was 1.22mg% and 0.32%, respectively.

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Magnesium diboride(MgB2) wires for applications

  • Patel, Dipak;Kim, Jung Ho
    • Progress in Superconductivity and Cryogenics
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    • v.18 no.1
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    • pp.1-5
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    • 2016
  • Field and temperature dependence of the critical current density, Jc, were measured for both un-doped and carbon doped $MgB_2/Nb/Monel$ wires manufactured by Hyper Tech Research, Inc. In particular, carbon incorporation into the $MgB_2$ structure using malic acid additive and a chemical solution method can be advantageous because of the highly uniform mixing between the carbon and boron powders. At 4.2 K and 10 T, Jc was estimated to be $25,000-25,300Acm^{-2}$ for the wire sintered at $600^{\circ}C$ for 4 hours. The irreversibility field, $B_{irr}$, of the malic acid doped wire was approximately 21.0 - 21.8 T, as obtained from a linear extrapolation of the J-B characteristic. Interestingly enough, the Jc of the malic acid doped sample exceeds $10^5Acm^{-2}$ at 6 T and 4.2 K, which is comparable to that of commercial Nb-Ti wires.

Chemical Composition and Antioxidant Activity of Korean Buckwheat (Fagopyrum esculentum) Pollen Grain Collected by Honey Bee, Apis mellifera (메밀화분의 성분 특성 및 항산화 활성)

  • Hong, In-Pyo;Woo, Soon-Ok;Han, Sang-Mi;Lee, Mi-Kyoung
    • Journal of Apiculture
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    • v.32 no.3
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    • pp.261-268
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    • 2017
  • We evaluated the nutritional composition including proximate, amino acid, vitamin, minerals, and the antioxidant activity of buckwheat (Fagopyrum esculentum) pollen grains collected by Apis mellifera bees, to be used as a species of forage plant with Quercus acutissima (acorn) and Actinidia arguta pollen grains. The content of crude protein and fat were found 14.43% and 5.67%, respectively. Eighteen amino acids from buckwheat pollen were found, including 8 essential amino acids. The predominant amino acids were glutamic acid, aspartic acid and lysine, accounting for about 42.7% of total free amino acids. The concentration of vitamin C was the highest value of 13.7 mg/100g, followed by $B_3$ (niacin) and $B_1$ among the detected vitamins. The predominant minerals were potassium (1197.95mg/100g), followed by phosphorus (962.77mg/100g) and magnesium (535.42mg/100g), whereas copper, zinc and manganese were detected as minor elements. Antioxidant activity and total phenolic content accounted for 8.1% at $500{\mu}g/ml$ extract and $2.25{\mu}g/mg$, respectively.

Nutritional Status and Requirements of Protein and Energy in Female Korean College Students Maintaining Their Usual and Activity(2) : Nitrogen Intake and Balance (자유로운 식이와 활동을 유지하는 한국 여대생의 에너지와 단백질대사에 대한 연구(2) : 질소섭취와 평형)

  • 김주연
    • Journal of Nutrition and Health
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    • v.28 no.4
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    • pp.259-267
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    • 1995
  • A study was conducted to investigate nitrogen balance and to estimate daily nitrogen requirement in 43 Korean female college students students maintaining their usual diet and activity levels. Nitrogen intake and excretion were measured in two separate peroids about one month apart, each period lasting for 3 days. Nitrogen intake was assessed by duplicate portion analysis of diet, and N excretion in faces and urine were measured during the study period. Mean daily nitrogen intake level was 129.3mg/kg B.W and the apparent digestibility of nitrogen was 76%. Mean daily urinary nitrogen excretion was 113.5mg/kg BW. 895 of total nitrogen intake. Mean daily nitrogen balance of subjects was -14.5mg/kg BW. Mean daily requirements of nitrogen for 0 balance, calculated by regression analysis of N balance and energy-adjusted N intake. were 1) 197.mg/kg B.W with the present energy intake level of the study subjects. 2) 157mg/kg B.W when energy intake is sufficient to maintain energy balance, and 30 130mg/kg B.W. when energy intake is Korean RDA level for moderate activity. When energy intake level is sufficient to meet their requirement, daily protein requirement for 0 balance is about 1.0g/kg B.W. The results of this study indicate that nitrogen intake level of young female college students is not sufficient to meet their requirements, and they should increase protein intake together with increase in energy intake.

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Fabrication of Magnesium Diboride Thin Films by Aerosol Deposition (에어로졸 증착법에 의한 $MgB_2$ 박막 제조)

  • Sinha, B.B.;Chung, K.C.;Jang, S.H.;Hahn, B.D.;Park, D.S.;Wang, X.L.;Dou, S.X.
    • Progress in Superconductivity
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    • v.13 no.2
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    • pp.122-126
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    • 2011
  • Superconducting $MgB_2$ thin films were fabricated by using a novel aerosol deposition technique wherein the pre-reacted powder is directly transformed into respective thin film. The formed thin films were characterized by X-ray diffraction technique and FE-SEM to understand its structure and morphology and the superconducting behavior has been characterized with the four probe resistivity measurement. The as-deposited thin films were formed into the frustrated amorphous structure, which were relaxed on the further heat treatment at $900^{\circ}C$ for 3 hrs. The relaxed amorphous $MgB_2$ thin films showed a comparatively high superconducting onset at about 38 K.

Effect of Hizikia Fusiforme Water Extracts on Mouse Immune Cell Activation (2주 동안의 톳 추출물 투여가 마우스의 비장세포와 Cytokine ($IL-1{\beta}$, IL-6, $TNF-{\alpha}$)의 생성량에 미치는 영향)

  • Ryu, Hye-Sook;Jung, Yun-Hee;Kim, Hyun-Sook
    • Journal of Nutrition and Health
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    • v.40 no.7
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    • pp.624-629
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    • 2007
  • Hizikia fusiforme(sea weed fusiforme) has long been used for food source in this country. This study was performed to evalute the immunomodulative effects of Hizikia fusiforme (sea weed fusiforme) in mouse, using in vivo experiments. In vivo experiment, different concentration (0, 50, 500 mg/kg B.W.) of Hizikia fusiforme water extracts were orally administrated into mouse every other day for two weeks. The proliferation of mouse splenocytes, the production of three cytokines ($IL-1{\beta}$, IL-6, $TNF-{\alpha})$ secreted by activated macrophage. Splenocyte proliferation was enhanced in mouse orally administrated with 50 mg/kg B.W. and 500 mg/kg B.W. concentration compared to that of control group. Especially, the highest proliferation of spleoncyte was seen from the mouse orally administrated at the concentration of 50 mg/kg B.W. Also, the mouse of Hizikia fusiforme water extracts supplementation group in the both concentrations showed enhanced levels of cytokine production by activated peritoneal macrophages compared to those in control group. The highest level of cytokine ($IL-1{\beta}$, IL-6, $TNF-{\alpha})$ production was observed at 50 mg/kg B.W. supplementation group with LPS stimulation in all cases.