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Development and Validation of an Analytical Method for Quinoxyfen in Agricultural Products using QuEChERS and LC-MS/MS (QuEChERS법 및 LC-MS/MS를 이용한 농산물 중 살균제 Quinoxyfen의 잔류시험법 개발 및 검증)

  • Cho, Sung Min;Do, Jung-Ah;Lee, Han Sol;Park, Ji-Su;Shin, Hye-Sun;Jang, Dong Eun;Choi, Young-Nae;Jung, Yong-hyun;Lee, Kangbong
    • Journal of Food Hygiene and Safety
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    • v.34 no.2
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    • pp.140-147
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    • 2019
  • An analytical method was developed for the determination of quinoxyfen in agricultural products using the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The samples were extracted with 1% acetic acid in acetonitrile and water was removed by liquid-liquid partitioning with $MgSO_4$ (anhydrous magnesium sulfate) and sodium acetate. Dispersive solid-phase extraction (d-SPE) cleanup was carried out using $MgSO_4$, PSA (primary secondary amine), $C_{18}$ (octadecyl) and GCB (graphitized carbon black). The analytes were quantified and confirmed by using LC-MS/MS in positive mode with MRM (multiple reaction monitoring). The matrix-matched calibration curves were constructed using six levels ($0.001-0.25{\mu}g/mL$) and the coefficient of determination ($R^2$) was above 0.99. Recovery results at three concentrations (LOQ, 10 LOQ, and 50 LOQ, n=5) were in the range of 73.5-86.7% with RSDs (relative standard deviations) of less than 8.9%. For inter-laboratory validation, the average recovery was 77.2-95.4% and the CV (coefficient of variation) was below 14.5%. All results were consistent with the criteria ranges requested in the Codex guidelines (CAC/GL 40-1993, 2003) and Food Safety Evaluation Department guidelines (2016). The proposed analytical method was accurate, effective and sensitive for quinoxyfen determination in agricultural commodities. This study could be useful for the safe management of quinoxyfen residues in agricultural products.

Change of Schottky barrier height in Er-silicide/p-silicon junction (어븀-실리사이드/p-형 실리콘 접합에서 쇼트키 장벽 높이 변화)

  • Lee, Sol;Jeon, Seung-Ho;Ko, Chang-Hun;Han, Moon-Sup;Jang, Moon-Gyu;Lee, Seong-Jae;Park, Kyoung-Wan
    • Journal of the Korean Vacuum Society
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    • v.16 no.3
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    • pp.197-204
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    • 2007
  • Ultra thin Er-silicide layers formed by Er deposition on the clean p-silicon and in situ post annealing technique were investigated with respect to change of the Schottky barrier height. The formation of Er silicides was confirmed by XPS results. UPS measurements revealed that the workfunction of the silicide decreased and was saturated as the deposited Er thickness increased up to $10{\AA}$. We found that the silicides were mainly composed of Er5Si3 phase through the XRD experiments. After Schottky diodes were fabricated with the Er silicide/p-Si junctions, the Schottky barrier heights were calculated $0.44{\sim}0.78eV$ from the I-V measurements of the Schottky diodes. There was large discrepancy in the Schottky barrier heights deduced from the UPS with the ideal junction condition and the real I-V measurements, so that we attributed the discrepancy to the $Er_5Si_3$ phase in the Er-silicides and the large interfacial density of trap state of it.

The Mouse Mutations Circling and Spinner are Allelic

  • Kyoung in Cho;Lee, Eun-Ju;Kim, Myoung-Ok;Kim, Sung-Hyun;Pakr, Jun-Hong;Jung, Boo-Kyung;Kim, Hee-Chul;Sol ha Hwang;Suh, Jun-Gyo
    • Proceedings of the KSAR Conference
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    • 2003.06a
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    • pp.90-90
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    • 2003
  • Circling mice were recorded to display profound deafness and a head-tossing and bidirectional circling behavior, showing an autosomal recessive mode of inheritance. In addition, the histological examination of inner ears revealed that the region around organ of Corti, spiral ganglion neurons and outer hair cells showed definite abnormality. On the other hand, a genetic linkage map was constructed in an intraspecific backcross between cir and C57BL/6J mice. The cir gene was mapped to a region between D9Mitl16/D9Mit15 and D9Mit38 on the mouse chromosome 9. Estimated distances between cir and D9Mitl16, and between cir and D9Mit38 are 0.70 $\pm$ 0.40 and 0.23 $\pm$ 0.23 cM, respectively. The markers in order was defined as follows: centromere-D9Mit182- D9Mit51/ D9Mit79/ D9Mit310- D9Mit212/ D9Mit184- D9Mit116/ D9Mit15- cir- D9Mit38- D9Mit20- D9Mit243- D9Mit16- D9Mit55/ D9Mit125- D9Mit281 Based on genetic mapping, we constructed for a YAC contig across cir region. They covered the entire region or cir and cir gene was located on between the lactotransferrin (ltf) and the macrotubule-associated protein (map4). It is known that sr gene is localized in 64cM of mouse chromosome 9. The two mouse were found to be allelic by complementation test. Recently the spinner mouse has been mapped to our cir region, and tmie gene were elucidated. And further study will be needed in circling mouse to prove tmie gene mutaiton.

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Effect of Suppressing the Activation of Macrophage Migration Inhibitory Factor by $Sambucus$ $williamsii$ $H_{ANCE}$ Extract & Pharmacopuncture Solution on Type II Collagen-induced Arthritis (접골목(接骨木)추출물 및 약침액에 의한 MIF 활성 조절능이 생쥐의 제2형 Collagen 유발 관절염에 미치는 영향)

  • Lee, Dong-Gun;Kim, Eun-Jung;Lee, Eun-Sol;Wang, Kai-Hsia;Cho, Hyun-Seok;Lee, Seung-Deok;Kim, Kap-Sung;Kim, Kyung-Ho
    • Journal of Acupuncture Research
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    • v.29 no.1
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    • pp.103-113
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    • 2012
  • Objectives : The purpose of this study is to evaluate effect of suppressing the expression of cyclo-oxygenase-type-2 (COX-2) as a consequence of inhibition macrophage migration inhibitory factor (MIF) activation by $Sambucus$ $williamsii$ $Hance$ (SWH) pharmacopunctureon rheumatoid arthritis (RA). Methods : In vitro test, synoviocytes extracted from type II collagen-induced arthritis (CIA) mouse's knee joint were cultivated After that, each well of synoviocytes was mixed with the extract of SWH at the dosage of $0.4mg/m{\ell}$, $0.6mg/m{\ell}$, $0.8mg/m{\ell}$, and $1.0mg/m{\ell}$ respectively, and cultivated for 24 hours after the addition. Reverse transcriptase - polymerase chain reaction (RT-PCR) is used to investigate the expression of MIF, Tumor necrosis factor (TNF)-${\alpha}$, COX-2 mRNA. $In$ $vivo$ test, thirty DBA female mice were used, and each ten mice were allocated into three group; normal group, CIA-elicitated group, and group treated with SWH pharmacopuncture on it's the point of $ST_{35}$ after CIA elicitation. It is investigated that change of mice foot thickness, histologic change of sliced synovial joint of mouse, and extent change of MIF, TNF-${\alpha}$, COX-2 in synovial membrane. Results : $In$ $vitro$ test, the expressions of cytokine(MIF, TNF-${\alpha}$, COX-2) mRNAs related to RA were dose-dependent decreased. In the SWH pharmacopuncture group, foot thickness and histologic change of sliced synovial joint were decreased comparing with CIA-elicitated group's change. In the SWH pharmacopuncture group, the suppression of MIF, TNF-${\alpha}$, COX-2 in synovial membrane was clearly shown comparing with CIA-elicitated group's change. Conclusions : It might be suggested that SWH pharmacopuncture mitigate tissue damage originated from rheumatoid arthritis by suppressing the expression of COX-2 as a consequence of inhibition MIF activation.

Effects of Integrative Korean Medical Treatment for a Failed Epidural Steroid Injections to L-spine Disk Herniation: A Retrospective Case Series (경막외 스테로이드 주사치료에 실패 후 한방복합치료에 의해 호전된 요추 추간판 탈출증 환자 10례 : 후향적 증례 연구)

  • Kim, Ji Su;Kim, Yoo Jong;Hong, Je Rak;Kim, Min Chul;Park, Han Sol;Kim, Seh Young;Seo, Young Woo;Lee, Sang Min;Seo, Young Hoon;Kim, Ki Ok;Kim, Tae Hun
    • Journal of Acupuncture Research
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    • v.32 no.4
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    • pp.203-211
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    • 2015
  • Objectives : The purpose of this study was to assess the effectiveness of integrative Korean Medical treatments for patients with L-spine disk herniation that showed no response to Epidural Steroid Injections (ESI). Methods : In this study, we reviewed the medical records of ten patients who showed no improvement or relapsed after ESI. The patients each received more than three weeks of integrative treatments at Mokhuri Neck&Back Hospital. The Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) was measured before and after treatment. A statistical analysis to compare before and after treatments was assessed using paired t-test the SPSS 12.0 Windows program. Results : After three weeks of treatment, patients showed a significant decrease in VAS and ODI scores compared to before receiving treatment. VAS scores decreased from $5.3{\pm}1.25$ to $1.9{\pm}0.99$ (p<0.001), and ODI scores decreased from $59.8{\pm}22.2$ to $32.7{\pm}14.11$ (p<0.001). Conclusions : Complex Korean Medical treatment showed effectiveness in the treatment of L-spine HIVD patients that showed no response to ESI, and more objective research is needed.

The characteristics of dye-sensitized solar cells using carbon nanotube in working and counter electrodes (작업전극과 상대전극에 탄소나노튜브를 이용한 염료감응 태양전지의 특성연구)

  • Kim, Bora;Song, Suil;Lee, Hak Soo;Cho, Namjun
    • Analytical Science and Technology
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    • v.27 no.6
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    • pp.308-313
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    • 2014
  • The effect of electrochemical characteristics of dye-sensitized solar cells (DSSC) upon employing multi-wall carbon nanotube (MWCNT) on both working electrode and counter electrode were examined with using EIS, J-V curves and UV-Vis absorption spectrometry. When 0.1 wt% of MWCNT was employed in the $TiO_2$-MWCNT composit on working electrode, the energy conversion efficiency increased about 12.5% compared to the $TiO_2$ only working electrode. The higher light conversion efficiency may attribut to the high electrical conductivity of MWCNT in $TiO_2$-MWCNT composite which improves the electron transport in the working electrode. However, higher amount of MWCNT than 0.1 wt% in the $TiO_2$-MWCNT composite decreases the light conversion efficiency, which is mainly ascribed to the decreased transmittance of light by MWCNT and to the decreased adsorption of dye onto $TiO_2$. The MWCNT employed counter electrode exhibited much lower light conversion efficiency of DSSC than the Pt-counter electrode, while the MWCNT-Pt counter electrode showed similar in light conversion efficiency to that of Pt-counter electrode.

Application and Validation of an Optimal Analytical Method using QuEChERS for the determination of Tolpyralate in Agricultural Products (QuEChERS법을 활용한 농산물 중 제초제 Tolpyralate의 최적 분석법 선발 및 검증)

  • Lee, Han Sol;Park, Ji-Su;Lee, Su Jung;Shin, Hye-Sun;Kim, Ji-Young;Yun, Sang Soon;Jung, Yong-hyun;Oh, Jae-Ho
    • Korean Journal of Environmental Agriculture
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    • v.39 no.3
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    • pp.246-252
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    • 2020
  • BACKGROUND: Pesticides are broadly used to control weeds and pests, and the residues remaining in crops are managed in accordance with the MRLs (maximum residue limits). Therefore, an analytical method is required to quantify the residues, and we conducted a series of analyses to select and validate the quick and simple analytical method for tolpyralate in five agricultural products using QuEChERS (quick, easy, cheap, effective, rugged and safe) method and LC-MS/MS (liquid chromatography-tandem mass spectrometry). METHODS AND RESULTS: The agricultural samples were extracted with acetonitrile followed by addition of anhydrous magnesium sulfate, sodium chloride, disodium hydrogencitrate sesquihydrate and trisodium citrate dihydrate. After shaking and centrifugation, purification was performed with d-SPE (dispersive-solid phase extraction) sorbents. To validate the optimized method, its selectivity, linearity, LOD (limit of detection), LOQ (limit of quantitation), accuracy, repeatability, and reproducibility from the inter-laboratory analyses were considered. LOQ of the analytical method was 0.01 mg/kg at five agricultural products and the linearity of matrix-matched calibration were good at seven concentration levels, from 0.0025 to 0.25 mg/L (R2≥0.9980). Mean recoveries at three spiking levels (n=5) were in the range of 85.2~112.4% with associated relative standard deviation values less than 6.2%, and the coefficient of variation between the two laboratories was also below 13%. All optimized results were validated according to the criteria ranges requested in the Codex Alimentarius Commission (CAC) and Ministry of Food and Drug Safety (MFDS) guidelines. CONCLUSION: In conclusion, we suggest that the selected and validated method could serve as a basic data for detecting tolpyralate residue in imported and domestic agricultural products.

Development and Validation of a Simultaneous Analytical Method for the Detection of Mefentrifluconazole and Triticonazole Fungicide in Agricultural Crops (농산물 중 메펜트리플루코나졸 및 트리티코나졸 살균제의 동시 분석법 개발 및 검증)

  • Park, Ji-Su;Lee, Han Sol;Lee, Su Jung;Shin, Hye-Sun;Shim, Jae-Han;Yun, Sang Soon;Jung, Yong-hyun;Oh, Jae-Ho
    • Korean Journal of Environmental Agriculture
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    • v.39 no.2
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    • pp.130-137
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    • 2020
  • BACKGROUND: Mefentrifluconazole and triticonazole are the triazole fungicides. The maximum residue levels for agricultural products need to be set up. Therefore, development of the official analytical method for determination of mefentrifluconazole and triticonazole residues from agricultural crops was necessary due to safety management, and then a simultaneous analytical method was developed for the determination of mefentrifluconazole and triticonazole in agricultural crops. METHODS AND RESULTS: Samples were extracted using acetonitrile and purified using dispersive solid phase extraction, and then detected with liquid chromatograph-tandem mass spectrometry (LC-MS/MS). Matrix-matched calibration curves (0.0025-0.25 ㎍/mL) were linear into a sample extract with r2>0.99. For validation, the recovery test was carried out at three fortification levels (LOQ, 10 LOQ and 50 LOQ) from agricultural samples. The results for mefentrifluconazole and triticonazole ranged between 92.3 to 115.3% and 91.4 to 108.5%, respectively and RSD (relative standard deviation) values were also below 6.0%. Furthermore, inter-laboratory was conducted to validate the method. CONCLUSION: All values were corresponded with the criteria ranges requested by both the CODEX (CAC/GL 40-1993, 2003) and MFDS guidelines (2016). Therefore, the proposed method can be used as an official analytical method for determination of mefentrifluconazole and triticonazole (triazole fungicides) in the Republic of Korea.

Validation of ICT·Living Lab-based Program Effectiveness for Improving Health and Quality of Life Among the Elderly in Small and Medium-Sized Cities (중소도시 지역 거주 고령자의 건강 증진을 위한 ICT-리빙랩(Living lab) 기반 프로그램 효과성 검증)

  • Park, Da Sol;Lee, Hey Sig;Park, Hae Yean
    • Therapeutic Science for Rehabilitation
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    • v.10 no.3
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    • pp.137-149
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    • 2021
  • Objective : This study aimed to verify the effectiveness of ICT-Living Lab-based programs to promote the health of elderly residents in small and medium-sized cities, thus, providing basic data for solving the health and quality of life problems faced by modern society. Methods : The tow-month program included 14 elderly individuals visiting senior center located in W City, from October to November 2019. The program was organized by consulting four senior experts and one ICT expert. The program consisted of 10 min for advance assessment, 10 min for preparation activities, 30 min for main activities, and 10 min for finishing, and 60 min for eight sessions over two months, once a week. Results : EQ-5D increased from 0.76 to 0.84, compared to pre-assessment(p=.009*). EQ-VAS scores increased from 36.43 to 65.71 (p=.001*). MMSE-DS increased from 21.21 to 24.14 (p=.000*). SGDS-K decreased from 3.36 to 3.21, but this was not statistically significant (p=.854). Conclusion : The ICT·Living Lab-based program could be used as a basic material for future research as one of the ways to improve health and quality of life by preventing and addressing the problems faced by the elderly in modern society.

Bacteriological Study about the Death of Cultured Doctor Fish, Garra rufa in the Aquarium

  • Lee, Ji-Yoon;Gang, Nam-I;You, Jin-Sol;Ko, Chang-Yong;Lee, Ki-Won;Han, Won-Min;Kim, Eunheui
    • Journal of Marine Life Science
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    • v.1 no.1
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    • pp.18-24
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    • 2016
  • Since April 2012, doctor fish in the breeding tank and in the quarantine tank in Hanwha Aquaplanet Yeosu Aquarium have been dying, accompanied by diffuse bleeding around the mouth, in the chin, and at the bottom of the abdomen. In this study, the cause of death would be examined through the bacteriological study of doctor fish and the rearing water quality in the aquarium. The water quality and the bacterial counts of the rearing water in the exhibit tank and in the quarantine tank were analyzed once a week, starting from August to November 2014. Water quality was measured based on the following data: temperature was in the range of 24.5~26.8℃, pH at 6.77~7.94, DO at 6.15~8.61 ppm, ammonia at 0~0.93 ppm, nitrite at 0.009~0.075 ppm, and nitrate at 1.1~40.9 ppm. Studies revealed that the differences in these water quality factors were not related to the death of doctor fish. Bacterial counts in the rearing waters of Garra rufa slightly increased to 103~104 CFU/ml, just before the death of the doctor fish. Twelve strains of bacteria were isolated from the dead fish and rearing waters. The isolates were identified as Aeromonas veronii, Citrobacter freundii, Pseudorhodoferax aquiterrae, Shewanella putrefaciens, and Vibrio anguillarum on the basis of 16S rRNA gene sequences. The most dominant species was C. freundii, which showed medium sensitivity to florfenicol and norfloxacin, and was resistant to amoxacillin, doxycycline, oxytetracycline, tetracycline, and trimethoprim. Ten isolates were confirmed to be pathogenic to the doctor fish. Doctor fish infected with C. freundii and S. putrefaciens showed high mortality in the experimental groups. These results indicate that the variation in bacterial numbers in the rearing water was related to the death of doctor fish. C. freundii and S. putrefaciens were directly implicated in causing the death of doctor fish in the aquarium.