• 한국영재학회:학술대회논문집
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• 한국영재학회 2003년도 춘계학술대회
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• pp.137-138
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• 2003

Understanding how and why people differ is a fundamental, if distant, goal of research efforts to bridge psychological and biological levels of analysis. General fluid intelligence (gF) is a major dimension of individual differences and refers to reasoning and novel problemsolving ability. A conceptual integration of evidence from cognitive (behavioral) and anatomical studies suggeststhat gF should covary with both task performance and neural activity in specific brain systems when specific cognitive demands are present, with the neural activity mediating the relation between gF and performance. Direct investigation of this possibility will be a critical step toward a mechanistic model of human intelligence. In turn, a mechanistic model might suggest ways to enhance gF through targeted behavioral or neurobiological intervent ions, We formed two different groups as subjects based on their scholarly attainments. Each group consists of 20 volunteers(aged 16-17 years, right-handed males) from the National Gifted School and a local high school respectively. To test whether individual differences in general intelligence are mediated at a neural level, we first assessed intellectual characteristics in 40 subjects using standard intelligence tests (Raven's Advanced Progressive Matrices, Wechsler Adult Intelligence Scale, Torrance Tests of Creative Thinking) administered outside of the MR scanner. We then used functional magnetic resonance imaging (fMRl) to measure task-related brain activity as participants performed three different kinds of computerized reasoning tasks that were intended to activate the relevant neural systems. To examine the difference of neural activity according to discrepancy in general intelligence, we compared the brain activity of both extreme groups (each, n=10) of the participants based on the standard intelligence test scores. In contrast to the common expectation, there was no significant difference of brain region involved in high-g tasks between both groups. Random effect analysis exhibited that lateral prefrontal, anterior cingulate and parietal cortex are associated with gF. Despite very different task contents in the three high-g-low-g contrasts, recruitment of multiple regions is markedly similar in each case, However, on the task with high 9F correlations, the Prodigy group, (intelligence rank: >99%) showed higher task-related neural activity in several brain regions. These results suggest that the relationship between gF and brain activity should be stronger under high-g conditions than low-g conditions.

• 한국동물위생학회지
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• 제28권3호
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• pp.203-213
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• 2005

Oxytetracycline, tetracycline, chlortetracycline and doxycycline in honey were separated by solid phase extraction (SPE) and determined with high performance liquid chromatography (HPLC) with UV/Visible detector. Analysis was carried out using following conditions: XTerra $C_8$ column $(3.9\times150mm\;i.d. 5{\mu}m)$, mobile phase composed of 0.01M oxalic acid : methanol : acetonitrile (820 : 80 : 100, v/v/v), isocratic pump at a flow rate of 0.9 ml/min. and $50{\mu}l$ of injection volume, UV/Visible detector with wavelength of 360nm. The calibration curves of four tetracyclines showed linearity $(\gamma^2>0.999)$ at concentration range of $100\~1,000 ng/ml$. The recoveries in fortified honey represented more than $70\%$ with low coefficient of variation $(<10\%)$ for concentration range of four tetracyclines. The detection limits for oxytetracycline, tetracycline, chlortetracycline and doxycycline were 13.8, 14.6, 26.2 and 24.9ng/g in acacia honey. respectively. We also monitored tetracyclines residue in domestic honey [n : 38, acacia (20), wild flower (18) ] and foreign honey [n=22, legally distributed (13), illegally distributed (9)] using modified Charm II screening and HPLC confirmation methods. Seven of the 60 samples $(11.7\%)$ were suspect positive using modified Charm II screening test. Chlortetracycline residue was found in one foreign honey (illegally distributed) tested at concentrations of 0.22 ppm. Conclusively, for more effective control of tetracyclines used in beekeeping should be further survey for residues in honey and also national guidelines (maximum residue limit : MRL) and methods should be obligatory.

• 한국물환경학회지
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• 제28권3호
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• pp.460-466
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• 2012

Perchlorate is used in a number of applications as an oxidizer in solid propellants, munitions and fireworks and is one of the endocrine disrupting chemicals, which interferes with iodide uptake into the thyroid gland. The purpose of this study was to investigate perchlorate occurrence and distribution with a results of analysis of 94 samples collected from military facilities in Korea from October 11 to October 23, 2011. Overall, among all of the 94 samples analyzed, perchlorate was detected in 6.4% of the total number of samples above $4{\mu}g/L$ (minimum reported limit) and the average concentration was $26.1{\mu}g/L$ and the maximum concentration was $107.7{\mu}g/L$ which was observed in surface water near manufacturing site of ammunition. By site classification, perchlorate was detected at one site in 4 manufacturing sites of ammunition and the maximum concentration was $107.7{\mu}g/L$ which was six times higher than that in guideline for perchlorate in Nakdong River and resulted from point source discharge. Perchlorate was detected at 3 sites in 78 measurements for shooting area and the maximum concentration was $12.4{\mu}g/L$ which was collected in dringking water and perchlorate in another sample was detected above MRL in shooting area was collected right away after shooting. These results showed that long term monitoring was needed considering weather conditions and shooting schedules.

• Mycobiology
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• 제34권2호
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• pp.67-72
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• 2006

Efficacy of resistance induction by the bacterial isolates Pseudomonas putida (TRL2-3), Micrococcus luteus (TRK2-2) and Flexibacteraceae bacterium (MRL412), which were isolated from the rhizosphere of plants growing in Jeju Mountain, were tested in a greenhouse. The disease severity caused by Phytophthora infestans was effectively reduced in the potato plants pre-inoculated with bacterial isolates compared with those of the untreated control plants growing in a greenhouse. In order to estimate the level of protection by the bacterial isolates, Mancozeb WP (Diesen $M^{(R)}$, Kyong nong) and DL-3-amino butyric acid (BABA) were pre-treated, whereas Dimethomorph WP ($Forum^{(R)}$, Kyong nong) and phosphonic acid ($H_{3}PO_{3}$) were post-treated the challenge inoculation with the pathogen. Disease severities of chemical pre-treated as well as post-treated plants were reduced compare to those of the untreated. The disease reduction in the plants pre-treated with Mancozeb WP was the highest, whereas that of post-treated with Dimethomorph WP was the lowest. The yields of plants pre-inoculated with three bacterial isolates were greatly increased than those of control plants. These results suggest that biological control by bacterial isolates might be an alternative strategy against late blight disease in potato plants growing in greenhouse.

• 한국환경농학회지
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• 제26권4호
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• pp.337-342
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• 2007

본 연구에서는 경북의 풍기와 상주에 있는 인삼재배포장에서 직접 시료를 채취하고, 이를 이용한 홍삼농축액제품을 제조하였다. 수삼과 홍삼농축액 중 유기인계와 유기염소계 농약을 GC-NPD와 GC-ECD로 각각 정량분석 하였으며 GC-MSD로 정성분석을 실시하여, 식품의약품안전청이 2007년 1월1일부터 시행한 농약잔류허용기준에 따라 안전성을 평가하였다. 풍기 수삼에서 유기인계 농약은diazinon을 비롯한pyrimethanil, tolclofos-methyl, metalaxyl, diethofencarb, parathion, cyprodinil, tolylfluanid와 kresoxim-methyl이 모두 불검출 되었다. 그러나 상주 수삼에서는 tolclofos- methyl이 평균 $0.054{\pm}0.008\;mg/kg$ 검출되어 수삼의 농약잔류허용기준 0.3mg/kg의 $18{\pm}2%$ 수준이었다. 풍기와 상주 수삼에서 유기염소계 농약은 BHC, DDT의 이성질체와 aldrin, azoxystrobin, captan, cypermethrin, deltamethrin, dieldrin, difenoconazole, endosulfan-sulfate, endrin, fenhexamid, quintozene, ${\alpha}-endosulfan$, ${\beta}$-endosulfan도 검출 되지 않았다. 한편 풍기와 영주의 인삼으로 제조한 홍삼농축액 중에도 유기인계와 유기염소계 농약은 모두 검출 되지 않았다.

• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.274-280
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• 2005

A chitinase was purified from the culture supernatant of Paenibacillus illinoisensis KJA-424 by protein precipitation, DEAE-Sephadex anion-exchange chromatography, and Sephadex G-150 gel filtration. The molecular weight of the purified chitinase was 54 kDa on SDS-PAGE and activity staining. Optimal pH and temperature were pH 5.0 and 60$^{circ}$C, the presence of 10 ruM Ag$^{+}$ and Hg$^{2+}$ inhibited the activity by $92.1/%$ and $97.7/%$, and the K$_{m}$ and V$_{max}$ values were 1.12 mg chitin mrl and 1.48$\mu$mol GlcNAc min$^{-1}$, respectively. The enzyme hydrolyzed tetramer to dimer, pentamer to dimer and trimer, and hexamer to dimer, trimer and tetramer, indicating an endo-splitting mechanism. The chitinase had no hydrolytic activity toward dimer and trimer. The chitinase inhibited the mycelial growth of Rhizoctonia solani, suggesting an antifungal property.

• 한국환경농학회지
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• 제39권2호
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• pp.122-129
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• 2020

BACKGROUND: Dissipation patterns of insecticides (acequinocyl, clothianidin, diflubenzuron, thiacloprid, and thiamethoxam) on strawberry grown in plastic-covered greenhouse were evaluated at 7 intervals including the preharvest interval after application. This study was performed to determine the residue concentrations, half-lives and dissipation rates in strawberry for the harvest periods. METHODS AND RESULTS: Acequinocyl, clothianidin, diflubenzuron, thiacloprid, and thiamethoxam were applied in accordance with critical good agricultural practices for strawberry. Strawberry samples were collected at 0, 1, 2, 3, 5, 7 and 10 days after application. Quantitaion was performed by HPLC/DAD and HPLC-MSMS system with C₁₈ column. The limit of quantitation (LOQ) values varied between were 0.00025~0.05 mg/kg on strawberry. The recoveries of acequinocyl, clothianidin, diflubenzuron, thiacloprid and thiamethoxam at two concentrations ranged from 70.9~104.9% on strawberry. The half-lives of pesticide dissipation on strawberry for two fields ranged from 1.3~8.2 days. The dissipation rates were evaluated according to the statistics method with a 95% confidence. CONCLUSION: The residue levels of insecticides (acequinocyl, clothianidin, diflubenzuron, thiacloprid, and thiamethoxam) on strawberry at 0-day after application were below the specified values by Korean MRL. To estimate dissipation rate constant of pesticides on crop for harvest periods, it is important to set the pre-harvest residue limit for human health and consumer protection in Korea.

• 한국환경농학회지
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• 제39권2호
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• pp.142-169
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• 2020

BACKGROUND: A new analytical method has been developed to determine 261 pesticide residues in herbal medicines. METHODS AND RESULTS: The extraction of pesticides was carried out by modified method of the Korea Food Standards Codex sample extraction and determination was performed using GC-MS/MS and LC-MS/MS. During the pre-treatment process of the test method, Solid-liquid separation was changed to centrifugation. The method was validated by the precision and accuracy results. 261 pesticides spiked at three level 20, 50, 100 ug/kg in herbal medicines. The limit of quantification of method were 4-40 ug/kg for GC-MS/MS and 2-45 ug/kg for LC-MS/MS, respectively. Among the pesticides analysed by GC-MS/MS and LC-MS/MS, 244 pesticides (94% of total number) in chinese matrimony vine and 224 pesticides (86% of total number) in korean angelica root and 231 pesticides (89% of total number) in jujube and 214 (82% of total number) in cnidium showed recoveries in the range of 70-120% with RSD⪯20%. CONCLUSION: These results indicated that GC-MS/MS and LC-MS/MS analysis with the sample extraction in this study can be applied to multi-residue analysis of pesticides in herbal medicines.

• 한국식품저장유통학회:학술대회논문집
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• 한국식품저장유통학회 2003년도 제23차 추계총회 및 국제학술심포지움
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• pp.150.1-150
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• 2003

열무의 안전한 생산을 위한 생산단계에서의 각 농약 잔류량 변화 추이와 최종 소비단계에서의 농산물 안전성 평가자료로 활용하기 위하여 실제 시험포장에 열무를 파종한 후 수확 10일 전에 4 종(diazinon, endosulfan, cypermethrin, cyhalothrin)의 살충제를 각 성분별로 안전사용 기준에 따라 기준량 및 배량의 처리구에 직접 살포하여 열무의 포장상태에서의 잔류량 감소(생물학적 반감기) 변화를 조사하였다. 각 농약별로 2 수준 농도의 표준물질을 첨가하여 실험한 결과 평균회수율은 diazinon 98.7∼99.9%, endosulfan 97.6∼98.5%, cypermethrin 98.3∼99.6%, cyhalothrin 98.4∼99.1%이였고, 검출한계는 diazinon 및 cypermethrin은 0.04 mg/kg, endosulfan은 0.012 mg/kg, cyhalothrin은 0.01 mg/kg 이었다. 약제 살포 후 분해속도가 빠른 성분은 diazinon ＞ endosulfan ＞ cypermethrin ＞cyhalothrin 순이었다. 작물체(열무)내에서 시간의 경과에 따른 잔류량의 변화를 1차 반응으로 표현하여 농약 4종의 살포농도별 생물학적 반감기를 산출한 결과, 기준량 살포의 경우 diazinon 0.9일, endosulfan 2.0일, cypermethrin 2.2일, cyhalothrin 2.5일 그리고 배량 살포의 경우에는 diazinon 1.1일, endosulfan 2.0일, cypermethrin 2.1일, cyhalothrin 2.2일로 나타났다. 안전한 농산물 생산을 위한 열무 중 약제 살포 후 수확일은 잔류허용기준(MRL)을 적용시킬 경우 기준량으로 볼 때 diazinon은 6일 후, endosulfan은 10일 후에 수확하는 것이 바람직한 것으로 나타났으며 합성 피레스로이드계인 cypermethrin과 cyhalothrin은 농약살포 후 2 시간 후에 농약 잔류량이 잔류허용기준 미만으로 나타났다.

• 대한족부족관절학회지
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• 제6권2호
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• pp.195-200
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• 2002

Purpose: To investigate the MRI and arthroscopic findings of osteochondral lesion of the talus which looked normal on plane radiography. Materials and methods: We investigated the MRI and arthroscopic findings of seven osteochondral lesions in which there were no abnormal finding on plane radiography and no cystic changes on MRI. Average age was 31 years(range, 19-43 years). Arthroscopic findings were classified according to the Ferkel's criteria. Results: History of injury was reported in all cases and the average duration from injury to presentation was 4 years and 4 months. Low signal change in T1WI was found in 6 of 7 lesions, no signal change in 1 case. Low signal change in T2WI was found in 4, no signal change in 3. 6 STIR images were obtained. High signal change was found in 3, no signal change in 2 and intermediate signal change was in 1. Arthroscopic grading was A in 1, C in 1, D in 2 , E in 1 and F in 2. We could not find any correlation between the findings on MRI and arthroscopic examination. Conclusion: We suggest arthroscopic examination is needed for accurate diagnosis of the osteochondral lesions of the talus which looked normal on plane radiography, because they have various MRl findings and high likelihood of existence of unstable cartilage lesions.