• Title/Summary/Keyword: Han-Ki Choi

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Monitoring of Pesticide Residues in Commonly Consumed Medicinal Agricultural Products (다소비 식·약공용농산물의 잔류농약 실태조사)

  • Hee-Jeong Choi;Yun-Sung Kim;Sang-Tae Kim;Nan-Joo Park;Yu-Mi Choi;Na-Young Yoo;Yoo-Li Han;Jeong-Hwa Seo;Jong-Sung Son;Myoung-Ki Park
    • Journal of Food Hygiene and Safety
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    • v.38 no.3
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    • pp.112-122
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    • 2023
  • We assessed the pesticide residues in the medicinal agricultural products distributed in Korea. Pesticide residues in 72 samples were analyzed using the QuECheRS method for 339 pesticides, using GC-MS/MS and LC-MS/MS. The pesticide residues were below the maximum residues limit (MRL) in 42 samples (58.3%); however, they exceeded the MRL in 5 samples (6.9%). These included 43 types of pesticides; 20 fungicides and 23 insecticides were detected 75 times and 58 times, respectively. Tebuconazole and carbendazim were the most detected fungicides, each 11 times. The levels of acetamiprid, cadusafos, chlorpyrifos, flubendiamide, fluopyram, and triazophos exceeded the MRL in Gogi berry, Omija, and Reishi mushroom. All of them were positive list system (PLS) items that lacked pesticide residue standards. Therefore, authorities should monitor the distributed medicinal agricultural products.

Biological Control of Tomato and Red Pepper Powdery Mildew using Paenibacillus polymyxa CW (Paenibacillus polymyxa CW를 이용한 고추 및 토마토 흰가루병 방제)

  • Kim, Yong-Ki;Choi, Eun-Jung;Hong, Sung-Jun;Shim, Chang-Ki;Kim, Min-Jeong;Jee, Hyeong-Jin;Park, Jong-Ho;Han, Eun-Jung;Jang, Bo-Kyung;Yun, Jong-Cheul
    • The Korean Journal of Pesticide Science
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    • v.17 no.4
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    • pp.379-387
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    • 2013
  • In order to improve practical utility of agro-microorganisms (AMs) which had been cultured and disseminated to promote plant growth and to control crop diseases, 51 isolates of AMs were collected from 18 agricultural extension centers in local government and screened for multi-functions such as antifungal activity, activities of phosphorus solubilization, IAA and siderophore production, nitrogen fixation, and hydrolytic enzyme activity. Finally we selected one isolate showing good antifungal activity and multi-functions related to plant growth and disease control. The selected isolate, Paenibacillus polymyxa CW, showed good inhibitory effect against plant pathogens, Pyricularia gresea, Colletotrichum acutatum, Fusarium oxysporum, Phomopsis sp., Aspergillus niger, Rhizoctonia solani and Phytophthora capsici. Suppressive effect of P. polymyxa CW against the used plant pathogens except for R. solani was much higher than that of P. polymyxa AC-1 storing in National Academy of Agricultural Science. We found P. polymyxa CW isolate showed good activity in siderophore and IAA formation, and nitrogen fixation. With P. polymyxa CW isolate, siderophore formation activity was similar to that of P. polymyxa AC-1, but IAA formation and nitrogen fixation activity was much higher than that of P. polymyxa AC-1. However neither P. polymyxa CW nor P. polymyxa AC-1 showed hydrolytic enzyme (chitinase, pectinase and cellulase) activity. The treatment of P. polymyxa CW with culture suspension of different cell density ($10^8$, $10^7$. $10^6$ cfu/ml) showed that the highest density reduced incidence of red pepper powdery mildew by 68.3% after 10 days of application. As application density of P. polymyxa CW was decreased, its control efficacy was proportionally decreased. In addition, when P. polymyxa CW was treated to control tomato powdery mildew at the same concentrations and their control effects were investigated after 7 days of inoculation, disease incidence was 0.03, 19.5, 45.7%, respectively, compared to 56.3% that of untreated check. Like red pepper powdery mildew, increase of application density of P. polymyxa CW resulted in increase of its control efficacy proportionally. P. polymyxa CW showed a density-dependent control efficacy against red pepper and tomato powdery mildews. Therefore we think that mode of action of the antagonist for suppressing two powdery mildew diseases might be antibiosis and density of more than $10^8cfu/ml$ was needed to control effectively the two diseases. On this basis, we think that P. polymyxa CW can be a promising control agent for suppressing powdery mildews of red pepper and tomato.

[ $^{18}F-FDG$ ] PET/CT in Multiple Myeloma: Is It Necessary to Include the Skull and Lower Extremity Distal to Mid-Thigh? (다발성 골수종에서의 $^{18}F$-FDG PET/CT: 전신영상 획득이 필요한가?)

  • Lee, Su-Jin; Choi, Joon-Young;Kim, Ki-Hyun;Lee, Eun-Jeong;Cho, Young-Seok;Hyun, Seung-Hyup;Lee, Ji-Young;Lee, Kyung-Han;Kim, Byung-Tae
    • Nuclear Medicine and Molecular Imaging
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    • v.42 no.1
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    • pp.39-43
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    • 2008
  • Purpose: We evaluated whether it was necessary to perform whole body acquisition of $^{18}F$-FDG PET/CT including whole skull and lower extremity (LE) distal to mid-thigh (MT) in patients with multiple myeloma (MM). Materials and Methods: Thirty patients underwent 45 whole body $^{18}F$-FDG PET/CT scans including skull and LE distal to MT. PET scans were divided by 2 subgroups according to the presence of abnormal focal $^{18}F$-FDG uptake in skull or LE distal to MT. Clinical characteristics including age, sex, and stages were compared between the 2 subgroups. Results: Of total 45 whole body PET/CT scans, focally increased abnormal FDG uptake in the skull or LE distal to MT suggesting myeloma involvement was found in 22 scans (48.9%) of 14 patients (46.7%). Skull lesions were more frequently observed than LE lesions distal to MT on PET (86.4% vs. 40.9%, p<0.005). There were no significant differences in age, sex, initial Durie/Salmon stage, and tumor burden at the time of PET scan suggested by serum hemoglobin level, serum calcium level, serum and urine paraprotein level, and serum creatinine level between the two subgroups. The presence of the skull or LE distal MT lesions on PET did not affect on the Durie/Salmon plus stage except only 1 case (1/22, 4.5%, p>0.05). Conclusion: Abnormal lesions in the skull or LE distal to MT on $^{18}F$-FDG PET/CT did not affect significantly on the tumor burden and Durie/Salmon plus stage of MM. Therefore, torso PET acquisition including head may be sufficient for evaluating patients with MM.

Effect of Characteristics of Grain and Flour on Color of Noodle Dough Sheet and Simple Test for Fe Content in Korean Wheat Cultivar (종실과 밀가루 특성이 국수 면대 색깔에 미치는 영향과 철 함량 간이 검정)

  • Kang, Chon-Sik;Kim, Kyeong-Hoon;Choi, Induck;Sin, Sang-Hyun;Son, Jae-Han;Cheong, Young-Keun;Lee, Choon-Ki;Park, Kwang-Geun;Park, Chul Soo
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.59 no.1
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    • pp.27-37
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    • 2014
  • This study was carried out to characterize the color of noodle sheet made from Korean wheat cultivars, which were then evaluated on grain and flour properties, in order to enhance the breeding-line selection for noodle wheat. In particular, a rapid method was applied to investigate the effects of iron (Fe) contents on the lightness of noodle sheet for the selection of breeding-lines with high Fe contents. Wheat flour lightness of Korean wheat cultivars had a negative correlation with ash (r = -0.634, P<0.01), protein (r = -0.635, P<0.01) and total polyphenols (r = -0.493, P<0.05). The noodle sheet color showed a positive correlation with lightness, but a negative correlation with test weight, 1000 kernels weight, PPO activity and total polyphenol contents. Also, upon the wheat flour properties, the ash, protein and total polyphenol contents had a negative correlation with the lightness of noodle sheet, and this relation varied depending on the year and cultivars. The Fe content had a negative relation with the color of wheat flour and the lightness of noodle sheet, and the potassium hexacyanoferrate(II) trihydrate (PHT) test resulted in blue color. There was no correlation between Fe contents and the color of grains with PHT treatment, but after grounding the whole grains, a negative correlation was found between Fe contents and redness (r = -0.665, P<0.001) and yellowness (r = -0.658, P<0.001) of whole wheat flour with PHT treatment. On the other hand, the lightness of wheat flour with PHT treatment showed a negative relation with Fe content.

Analysis of Contributing Factor for Cation Ratio to Calcium in Nutrient Solution on the Incidence of Blossom-end Rot in Sweet Pepper 'RZ208' Grown in Hydroponics (파프리카 배꼽썩음과 발생에 미치는 배양액 내 칼슘에 대한 양이온 기여인자 분석)

  • Lee, Hye-Jin;Oh, Jeong-Sim;Choi, Ki-Young;Lee, Yong-Beom;Bae, Jong-Hyang;Rhee, Han-Cheol;Kim, Dong-Eok
    • Horticultural Science & Technology
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    • v.30 no.1
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    • pp.27-33
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    • 2012
  • This study aimed to investigate the responses of plant growth and blossom-end rot (BER) incidence to calcium (Ca) and its three kinds of antagonistic cations (K, Mg, and $NH_4$-N) with various ratios in nutrient solution for sweet paper (Capsicum annuum L. 'RZ208'). Both Ca to each cation and Ca to a series of cation combinations, such as potassium (K), ammonium nitrate ($NH_4$), or magnesium (Mg) were more influential to the fruit growth and quality than plant growth. Especially, the BER incidence was significantly influenced by the ratio treatments. For examples, when Ca:(K + Mg) or Ca:(K + Mg + $NH_4$) ratio was 1:2 the highest incident rate of BER about 70.3 or 86.3% was observed, lowering the marketable yield to 19 or 13.7% of the total yield, respectively. The correlation coefficiencies (= r) to relationships between the BER and K as well as BER and $NH_4$ were 0.82 (P < 0.05) and 0.65 (P < 0.05), respectively. Combination only with the Mg element was not correlated with the BER incidence. However, when both of the K and Mg concentrations were 0.65 (P < 0.05). The highest correlation coefficiency, 0.92 (P < 0.05), was found to a relationship between the BER and the tree elemental combination.

Effect of Wollastonites on Silica Uptake by Rice Plant (규회석(珪灰石)의 가용성(可溶性) 규산함량(珪酸含量)이 수도(水稻)의 규산흡수(珪酸吸收)에 미치는 효과)

  • Lee, Yun Hwan;Choi, Eae Ung;Han, Ki Hak
    • Korean Journal of Soil Science and Fertilizer
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    • v.6 no.4
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    • pp.221-226
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    • 1973
  • In order to investigate the silica effect of insufficient wollastonite to the official standard (above than 15% of suluble silica (N/2 HCl) on rice plant as silica fertilizer, 9 kinds of wollastonites and slag were adopted to examine the amount of silica absorbed by rice straw during growing period, and soluble silica of wollastonites extracted by 7 buffer solutions were compared with silica content in rice straw. Crystalls of ingredient in wollastonite ores were identified by X-ray diffractometer. The results were that silica content of rice plant at growing stages were increased as same ratio of soluble silica. content in wollastonite. Wollastonite containing more than 10% of souble silica (N/2 HCl) could be applied as fertilizer because absorbed amount of silica by rice plant from them are higher than from slag which contained 30% of soluble silica. Wollastonite powder mixed with impure ores in which soluble silica could not be extracted had the same effect on silica absorption of straw as wollastonite powder which contained conformable amount of soluble silica. The soluble silica of wollastonite extracted by buffer solutions (2% citric acid, N. NaOAc, N. $NH_4OAc$, Petermann solution, 0.1M. EDTA, and Hot water) had high significant relation to silica content in rice straw, but soluble silica extracted N/2 hydrochloric acid solutilon, also, had deep relation to them in rice straw. The adequate solution to extract silica from wollastonites is N/2 hydrochloric acid solution because its extracted silia amount is much higher than other solution (about one hundred times) and can be determined by gravimetric analysis. X-ray diffraction pattern would identify qualitatively purity of wollastonite, and large amount of soluble silica was extracted from wollastonite which was appeared to be weathered.

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Responses of Plasma IGF-1, IGFBPs and Hepatic GH Receptor to Growth Hormone Releasing Peptides (GHRP)-2 Administration and Energy Level in Wethers (거세면양에 있어서 에너지수준에 GHRP-2의 투여가 혈장 IGF-1, IGFBPs 및 hepatic GH 수용체에 미치는 반응)

  • Lee, Hong-Gu;Jin, Young-Cheng;Hidari, Hisashi;Choi, Yun-Jaie;Kim, Seon-Ku;Shin, Teak-Soon;Cho, Byung-Uuk;Kim, Yong-Gyun;Kim, Keun-Ki;Son, Hong-Joo;Lee, Sang-Mong;Park, Hyun-Chul;Kang, Han-Seok
    • Journal of Life Science
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    • v.18 no.7
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    • pp.931-939
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    • 2008
  • The purpose of this study was to determine the effect of energy supplement on responses of plasma insulin-like growth factor (IGF)-1 and IGF binding proteins (IGFBPs) to growth hormone-releasing peptide-2 (GHRP-2) administration in normal protein-fed wethers, and to observe the effect of GHRP-2 treatment on hepatic growth hormone (GH) receptor in well-fed wethers. Plasma IGF-1 and 39-42 kDa IGFBP-3 during the HENP (CP, crude protein 0.34 and TDN, total digestible nutrients 1.83 kg/day DM, dry matter intake) treatment period were higher than in the LENP (CP 0.32 kg and TDN 0.87 kg/day DM intake) period (P<0.05). The response of GH was stimulated by GHRP-2 ($12.5\;{\mu}g/kg$ body weight/day) administration during both of the feed treatment periods (P<0.05). The area under curve (AUC) increment and average concentration of GH (0-180 min) with GHRP-2 administration was higher during HENP treatment than LENP treatment (P<0.01). During the HENP treatment period from day 1 to day 7 of twice daily GHRP-2 treatment, the plasma IGF-1 increment was increased on days 2, 6 and 7 of GHRP-2 administration (P<0.05). On the basis of ligand blotting, the proportions of plasma 39-43 kDa IGFBP-3 during the HENP treatment period only showed a significant difference on days 6 and 7 with GHRP-2 administration. No significant difference in the specific binding of $^{125}I-labeled$ oGH to hepatic membranes was detected between the saline and GHRP-2 treatments of the HENP-fed wethers. These results suggest that the nutritional balance between energy and protein may affect the endogenous GH / IGF-1 axis as well as plasma IGFBP-3 levels.

Investigation of the Signal Characteristics of a Small Gamma Camera System Using NaI(Tl)-Position Sensitive Photomultiplier Tube (NaI(Tl) 섬광결정과 위치민감형 광전자증배관을 이용한 소형 감마카메라의 신호 특성 고찰)

  • Choi, Yong;Kim, Jong-Ho;Kim, Joon-Young;Im, Ki-Chun;Kim, Sang-Eun;Choe, Yearn-Seong;Lee, Kyung-Han;Joo, Koan-Sik;Kim, Byung-Tae
    • The Korean Journal of Nuclear Medicine
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    • v.34 no.1
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    • pp.82-93
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    • 2000
  • Purpose: We characterized the signals obtained from the components of a small gamma camera using Nal(Tl)-position sensitive photomultiplier tube (PSPMT) and optimized the parameters employed in the modules of the system. Materials and Methods: The small gamma camera system consists of a Nal(Tl) crystal ($60{\times}60{\times}6mm^3$) coupled with a Hamamatsu R3941 PSPMT, a resister chain circuit, preamplifiers, nuclear instrument modules (NIMs), an analog to digital converter and a personal computer for control and display. The PSPMT was read out using a resistive charge division circuit which multiplexes the 34 cross wire anode channels into 4 signals (X+, X-, Y+, Y -). Those signals were individually amplified by four preamplifiers and then, shaped and amplified by amplifiers. The signals were discriminated and digitized via triggering signal and used to localize the position of an event by applying the Anger logic. The gamma camera control and image display was performed by a program implemented using a graphic software. Results: The characteristics of signal and the parameters employed in each module of the system were presented. The intrinsic sensitivity of the system was approximately $8{\times}10^3$ counts/sec/${\mu}Ci$. The intrinsic energy resolution of the system was 18% FWHM at 140 keV. The spatial resolution obtained using a line-slit mask and $^{99m}Tc$ point source were, respectively, 2.2 and 2.3 mm FWHM in X and Y directions. Breast phantom containing $2{\sim}7mm$ diameter spheres was successfully imaged with a parallel hole collimator. The image displayed accurate size and activity distribution over the imaging field of view Conclusion: We proposed a simple method for development of a small gamma camera and presented the characteristics of the signals from the system and the optimized parameters used in the modules of the small gamma camera.

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Effect of Cobalt (II) on the Fertilization and Embryo Development of the Sea Urchin ($Hemicentrotus$ $pulcherrimus$) (코발트(II)가 말똥성게($Hemicentrotus$ $pulcherrimus$)의 수정 및 배아 발생에 미치는 영향)

  • Hwang, Un-Ki;Ryu, Hyang-Mi;Choi, Yong-Hwan;Lee, Seung-Min;Kang, Han-Seung
    • Korean Journal of Environmental Biology
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    • v.29 no.4
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    • pp.251-257
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    • 2011
  • Cobalt is a naturally occurring element found in rocks, soil, water and/or is among the harmful pollutants as generated by industrialized. In the environment, cobalt has two oxidation states, cobalt (II) (Co (II)) and cobalt (III) (Co (III)). If coastal water is contaminated by cobalt, it through the food chain can have an impact on marine ecosystems. Therefore, we examined the gametotoxic and embryotoxic effects of Co (II) at various concentrations (10, 100, 500, 1000, 2500 ppb) in the sea urchin $Hemicentrotus$ $pulcherrimus$. Spawning was induced by injecting 1 mL of 0.5 M KCl into coelomic cavity. Males released white or cream-colored sperms and females released yellow or orange-colored eggs. Experiment was begun within 30 min the collection of both gametes. The fertilization and embryo development rates test were performed for 10 min and 64 h after fertilization, respectively. The fertilization rates in the control condition (not including Co (II)) and experimental group were not significantly changed. The embryo development rates in the control condition were greater than 90% and were significantly decreased with concentration dependent manner. The normal embryogenesis rate was significantly inhibited in exposed to cobalt (II) ($EC_{50}$=71.84 ppb, 95% Cl=16.71-203.36 ppb). The NOEC and LOEC of normal embryogenesis rate were <10 ppb and 10 ppb, respectively. These results suggest that the early embryo stages of $H.$ $pulcherrimus$ have toxic effect at greater than 10 ppb of Co (II) concentration.

Single Dose Oral Toxicity of Schisandrae Semen Essential Oil in ICR Mice (ICR 마우스를 이용한 오미자 종자 정유의 단회경구투여 독성시험)

  • Han, Min Ho;Kim, Joo Wan;Kim, Ki Young;Kim, Sung Goo;Yu, Gyeng Jin;Cho, Yong Bok;Hwang, Hye Jin;Kim, Byung Woo;Kim, Cheol Min;Choi, Yung Hyun
    • Journal of Life Science
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    • v.24 no.2
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    • pp.191-195
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    • 2014
  • Essential oils extracted or purified from various plants have shown various beneficial effects. Seed parts of Schizandra chinensis Baillon (Schisandrae Semen) have been used as a traditional medicine for thousands of years in parts of Asia, including Korea, China, and Japan. However, the pharmacological mechanisms of essential oils purified from S. fructus (S. chinensis Baillon) remain largely unresolved. The aim of this study was to investigate the safety of Schisandrae Semen essential oil (SSeo) by a single- dose toxicity study in mice. SSeo was orally administered at a dose of 5,000 mg/kg in ICR mice. All animals were sacrificed after 14 days of treatment. After a single administration, mortality, clinical signs, body weight changes, and gross pathological findings were observed for 14 days. We also measured parameters of organ weight, clinical chemistry, and hematology. No toxicological change related to the test substance or mortality was observed after administration of a single oral dose of SSeo. There were no adverse effects on clinical signs, body weight, or organ weight and no gross pathological findings in any treatment group. The clinical chemistry and hematological parameters were within the normal ranges except total bilirubin. Therefore, the approximate lethal dose for oral administration of SSeo in mice was considered to be over 5,000 mg/kg. The results on the single-dose toxicity of SSeo indicate that it is not possible to reach oral dose levels related to death or dose levels with any harmful side effects.