• Analytical Science and Technology
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• v.26 no.3
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• pp.174-181
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• 2013

Pyrifluquinazon is classified with a quinazoline insecticide that regulates food intake by controling the feeding behavior acting on the endocrine or nervous system of pests such as aphids and white fly. To keep safety on pyrifluquinazon residues in agricultural commodities a simple, accurate and rapid analytical method was developed and validated using high performance liquid chromatograph (HPLC-UVD). The pyrifluquinazon residues acidified with 1% formic acid in samples were extracted with acetonitrile and partitioned with hexane subsequently to dichloromethane then purified with silica solid phase extraction (SPE) cartridge. The purified samples were detected using HPLC-UVD. The method was validated using apple and pear spiked with pyrifluquinazon at 0.02, 0.05 and 0.1 mg/kg and hulled rice, pepper, soybean at 0.05 and 0.1 mg/kg. Average recoveries were 70.5~107.9% with relative standard deviation less than 10%. The result of recoveries and overall coefficient of variation of a laboratory results in Gwangju regional FDA and Daejeon regional FDA was followed with Codex guideline (CODEX CAC/GL 40). This method is appropriated at pyrifluquinazon residues determination and will be used as official method of analysis.

• The Korean Journal of Pharmacology
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• v.22 no.2
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• pp.105-114
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• 1986

This study was undertaken to search for a new antiarrhythmic agent in natural plants. Extracts of Buxus microphylla var. koreana Nakai have been used as folk remedies of several diseases, including malaria and venereal disease, but any study on the pharmacological actions of this plant has not yet been carried out and its active ingredients have not been identified. In our laboratory, we isolated buxuletin (nonalkaloid) and cyclobuxine D (steroidal alkaloid) from Buxus microphylla var. koreana Nakai and reported their pharmacological actions: diuretic effects of buxuletin in rabbits and hypotensive effect of cyclobuxine D in rats. In the present study, we investigated the effect of cyclobuxine D on isolated frog heart and heart rate in urethane anesthetized rats. In order to clarify the mechanism of bradycardic effect of cyclobuxine D, we examined the changes of the ECG parameters (PR, QRS and R ${\alpha}$ T interval) produced by intravenous injection of cyclobuxine D in anesthetized rats. Cyclobuxine D depressed the contractile force in isolated frog heart and exerted a dose-dependent bradycardic effect in anesthetized rats. Intracerebroventricular injection of cyclobuxine D caused a fall in blood pressure and an increase in heart rate, but those effects were not significant. Cyclobuxine D prolonged the PR interval and RaT interval (${\alpha}$ Tindicates the apex of T), but was without significant effects on the duration of the QRS complex and PRc in urethane anesthetized rats.

• Nutrition Research and Practice
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• v.12 no.3
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• pp.199-207
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• 2018

BACKGROUND/OBJECTIVES: Fermented Laminaria japonica (FL), a type sea tangle used as a functional food ingredient, has been reported to possess cognitive improving properties that may aid in the treatment of common neurodegenerative disorders, such as dementia. MATERIALS/METHODS: We examined the effects of FL on scopolamine (Sco)- and ethanol (EtOH)-induced hippocampus-dependent memory impairment, using the Passive avoidance (PA) and Morris water maze (MWM) tests. To examine the underlying mechanisms associated with neuroprotective effects, we analyzed acetylcholine (ACh) and acetylcholinesterase (AChE) activity, brain tissue expression of muscarinic acetylcholine receptor (mAChR), cAMP response element binding protein (CREB) and extracellular signal-regulated kinases 1/2 (ERK1/2), and immunohistochemical analysis, in the hippocampus of mice, compared to current drug therapy intervention. Biochemical blood analysis was carried out to determine the effects of FL on alanine transaminase (ALT), aspartate transaminase (AST), and triglyceride (TG) and total cholesterol (TC) levels. 7 groups (n = 10) consisted of a control (CON), 3 Sco-induced dementia and 3 EtOH-induced dementia groups, with both dementia group types containing an untreated group (Sco and EtOH); a positive control, orally administered donepezil (Dpz) (4mg/kg) (Sco + Dpz and EtOH + Dpz); and an FL (50 mg/kg) treatment group (Sco + FL50 and EtOH + FL50), orally administered over the 4-week experimental period. RESULTS: FL50 significantly reduced EtOH-induced increase in AST and ALT levels. FL50 treatment reduced EtOH-impaired step-through latency time in the PA test, and Sco- and EtOH-induced dementia escape latency times in the MWM test. Moreover, anticholinergic effects of Sco and EtOH on the brain were reversed by FL50, through the attenuation of AChE activity and elevation of ACh concentration. FL50 elevated ERK1/2 protein expression and increased p-CREB (ser133) in hippocampus brain tissue, according to Western blot and immunohistochemistry analysis, respectively. CONCLUSION: Overall, these results suggest that FL may be considered an efficacious intervention for Sco- and EtOH-induced dementia, in terms of reversing cognitive impairment and neuroplastic dysfunction.

• Applied Biological Chemistry
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• v.26 no.2
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• pp.125-131
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• 1983

Formal net charges, bond populations, atomic orbital coefficients, energy components and conformation of dimethyl-2,2-dichlorovinylphosphate have been studied theoretically by using the CNDO/2 molecular orbital calculation method in attempt to describe the reactivity and the stability of the molecule. From the analysis of rate equation, molecular orbital calculations and identification of the hydrolysis products, 2,2-dichloroacetaldehyde and dimethylphosphoric acid, a mechanism of the hydrolysis of dimethyl-2,2-dichlorovinylphosphate(DDVP) has been proposed. The hydrolysis of DDVP proceeds through the mechanism of nucleophilic addition, typical Micheal reaction in basic media. Therefore, it appears probable that the attack by strong nucleophile, hydroxide ion occurs at the increased positive charge $C_2({\alpha})$ atom of a staggered conformation due to the inductive effect (-)I>(+)R of 2,2-dichlorovinyl, electron-attracting group. And then, the hydrolytic scission involves the $C_2({\alpha})-O_3$, ${\pi}-anti-bonding\;orbital({\pi}^*)$ in the subsequent reaction in aqueous solution.

• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.4
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• pp.256-264
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• 2004

Vegetation structure was investigated to provide basic information on revegetation of abandoned coal mine lands in Borim, Sungwon, Hyeopjeong, Daedong and at a control site in Taebaek. The upper layer of the control site consists of 7 species and the Importance Value was highest for Pinus densijlora, but there were no species in the four abandoned coal mines. The number of dominant species in the middle layer of each coal mine site was 2 for Borim, 2 for Sungwon, 3 for Hyeopjeong and 2 for Daedong. In the case of the lower layer in Borim, Sungwon, Hyeopjeong and Daedong, there were 12, 14, 9 and 8 species, respectively. The lower level importance values were highest for Pinus densiflora in Borim, for Amorpha fruticosa in Sungwon and for Rubus crataegifolius in the Hyeopjeong and Daedong coal mines. Weigela subsessilis, R. crataegifolius, P. densiflora, Betula platyphylla var. japonica, Stephanandra incisa, Lespedeza crytobotrya and A. fruticosa appeared in the lower layers of abandoned coal mines. Species diversity of the lower and the herbaceous layers ranged from 0.800 to 0.952 and 0.699 to 0.907 in abandoned coal mines. Evenness and dominance in all abandoned coal mines ranged from 0.840 to 0.949 and 0.051 to 0.160.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1998.11a
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• pp.72-72
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• 1998

원자력발전소 1차계통내 밸브의 경면처리(hardfa따1잉에 사용되는 재료는 $90~343^{\circ}C$의 고온과 높은 접촉응력 그리고 급격한 압력변화가 일어나는 환경에서 사용되기 때문에 내마모성과 내식성 그리고 cavitation erosion 저항성이 우수한 Co계 Stellite 합금이 현재 사용되어진다. 그러나 Co가 원력발전소 1차계통의 방사선장을 형성하는 주요 원소로 알려지면서 S Stellite 합금을 대체할 수 있는 Fe계 경면처리용 합금을 개발하려는 연구가 진행되고 있다. 현재 Fe계 경면처리용 합금의 개발은 적절환 팝금원소를 첨가하여 적충결함에너지를 낮춤 으로써 전위의 교차슬립을 억제하여 표면을 경화시키고, 소성변형을 억제하여 마모저항성을 향상시키려는 방법으로 연구가 진행되고 있다. 본 연구에서는 Fe-Cr-Ni-Si-C 합금에 Fe계 합금의 적충결함에너지를 감소시키는 것으로 알려진 vanadium을 0, 1, 2wt%첨가하여 첨가량의 변화가 cavitation erosion 저항성에 미치 는 영향을 조사하였다. Cavitation erosion 실험은 초음파를 이용하여 미세한 기포를 발생시키는 vibratory type으로 A ASTM G-32 규격에 따라 제작된 실험장치를 이용하여 $25{\pm}2^{\circ}C$의 온도의 증류수 속에 잠긴 상태에서 실시하였다. 시면은 지름 16mm, 두게 7mm의 버턴형태로 vanadium 첨가량을 변화시킨 조성을 아크 용융 방법을 이용하여 제작하였으며 hom끝단부에 부착하여 cavitation e erosion 저항성 살험을 하였다. 시편의 cavitation erosion 실험시간에 따른 무게감소량을 측 정하였으며 cavitation erosion 시킨 시편의 표면을 SEM으로 관찰하였다.겨지는 열전달 매체액 과 신규 부식억제제가 적용된 시스템 등 객관적으로 확인된 부식억제제 시스랩에 대 하여 다양한 평가 방법을 동원 비교분석하고자 하였다. 실험은 KSM 2142에 의한 무게감량법, 분극곡선 측정에 의한 $E_P$(공식개시전위), $E_R$(재부동태화전위) 측정, 시간에 따른 자연전위 변화 측정 빛 이때의 부식속도(선형분극법), 인위적인 피막 파괴 전,후 의 전위 변화 및 부식속도 측정법에 의한 국부부식 발달 저지능 등을 평가하여 각 실험결과를 비교분석하여 보았다. 수록 민감하여 304 의 IGSCC 와 매우 유사한 거동을 보인다. 본 강연에서는 304 와 600 의 고온 물에서 일어나는 IGSCC 민감도에 미치는 환경, 예민화처리, 합금원소의 영향을 고찰하고 이에 대한 최근의 연구 동향과 방식 방법을 다룬다.다.의 목적과 지식)보다 미학적 경험에 주는 영향이 큰 것으로 나타났으며, 모든 사람들에게 비슷한 미학적 경험을 발생시키는 것 이 밝혀졌다. 다시 말하면 모든 사람들은 그들의 문화적인 국적과 사회적 인 직업의 차이, 목적의 차이, 또한 환경의 의미의 차이에 상관없이 아름다 운 경관(High-beauty landscape)을 주거지나 나들이 장소로서 선호했으며, 아름답다고 평가했다. 반면에, 사람들이 갖고 있는 문화의 차이, 직업의 차 이, 목적의 차이, 그리고 환경의 의미의 차이에 따라 경관의 미학적 평가가 달라진 것으로 나타났다.corner$적 의도에 의한 경관구성의 일면을 확인할수 있지만 엄밀히 생각하여 보면 이러한 예의 경우도 최락의 총체적인 외형은 마찬가지로 $\ulcorner$순응$\lrcorner$의 범위를 벗어나지 않는다. 그렇기 때문에도 $\ulcorner$

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.279-279
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• 2007

비휘발성 메모리 Fe-RAM은 빠른 정보처리 속도와 전원공급이 차단되었을 때도 계속 정보를 유지할 수 있는 비휘발성 특징과 더불어 저전압, 저전력 구동의 장점이 있어서, 차세대 메모리로 많은 주목을 받고 있다. FeRAM에 사용되는 강유전체는 주로 Pb(Zr,Ti)$O_3$가 적용되었는데, 최근에는 비납계 강유전체의 연구도 활발히 이루어지고 있다. 이러한 비납계 강유전체 중에서 가장 특성이 우수한 물질은 $(Bi,La)_4Ti_3O_{12}$ (BLT) 이다. 그런데 BLT는 결정 방향에 따른 강한 이방성의 강유전 특성을 나타내기 때문에 BLT 박막을 이용하여 Fe-RAM 소자 등을 제작하기 위해서는 결정의 방향성을 세심하게 제어하는 것이 매우 중요하다. 지금까지 연구된 BLT 박막의 방향성 조절결과를 보면, BLT 박막을 스핀 코팅 법 (spin coating method)으로 증착하고, 핵생성 열처리 단계를 조절하여 무작위 방향성을 갖는 박막을 제조하는 방법이 일반적이었다. 그런데 이러한 스핀 코팅법에서의 핵생성 단계의 제어는 공정 조건 확보가 너무 어려운 단점이 있다. 이러한 어려움을 극복할 수 있는 대안은 스퍼터링 증착법(sputtering deposition method), PLD (pulsed laser deposition)법 등과 같은 PVD (physical vapor deposition) 법의 증착방법을 적용하는 것이다. PVD 법으로 증착하는 경우에는 이미 박막 내에 무수한 결정핵이 존재하기 때문에 핵생성 단계가 필요가 없게 된다. PVD 증착법의 적용을 위해서는 타겟의 제조 및 평가 실험이 선행되어야 한다. 그런데 벌크 BLT 재료의 소결공정 조건과 전기적 특성에 관한 연구 결과는 거의 발표가 되지 않고 있다. 본 실험에서는 $Bi_2O_3,\;TiO_2,\;La_2O_3,\;Nb_2O_5\;and\;Al_2O_3$ 분말들을 이용하여 최적의 조성을 구하기 위하여 $Nb^{+5}$ 와 $Al^{+3}$을 $Ti^{+4}$ 자리에 소량 치환시켜 제조하였다. 혼합된 분말을 하소 후 pellet 형태로 성형하여 소결을 실시하였다. 시편을 1mm 두께로 연마하고, 양면에 silver 전극을 인쇄하여 전기적 특성을 측정하였다. 측정결과 $Ti^{+4}$ 자리에 $Nb^{+5}$를 치환하여 제조한 시편에서 $2P_r{\sim}31\;{\mu}c/cm^2$정도의 매우 우수한 특성을 얻었다.

• The Journal of Korean Society for School & Community Health Education
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• v.6
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• pp.49-63
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• 2005

The purpose of this study was to investigate the weight control behaviors, the degree of fatness and dance major on behalf of finding the effects of eating disorders. 779 female high school students, 283 dance major students and 496 general major students, were participated in the study. A self-reporting type of questionnaire survey was conducted during the period from $6^{th}$ May to $18^{th}$ April of 2005. Collected data were processed using SPSSW in 12.0; they were analysed through frequencies, percentages, means and standard deviation, and stepwise multiple regression analysis. The results of this study are as follows : 1. With regard to the level of eating disorders(EAT-26), 33.9% of risk group of eating disorder female dance students, and 13.7% of risk group of eating disorder female general major students. Weight-control behaviors in this research were 1) weight control concerns, 2) weight control trial, 3) weight control methods (prescription of M.D., ways of weight control), 4) eating habits. First, 56.6% of subjects had high concerns about weight control, and 92% of subjects had tried weight control. Second, only 5.1% of subjects were prescribed by M.D. Third, subjects had been using wrong methods(25.7%) of weigh control such as fasting, using drugs, vomiting, wearing laps etc. Fourth, 42.7% of the subjects had bad eating habits. The degree of fatness was as follows: 1) BMI(Body Mass Index), 2) self report about weight 3) distorted body image. Depending upon the BMI, the subjects with obesity were not found in female dance students; Comparatively, 36.9% of dance students were fat and 1.4% of the students were very fat. In terms of distorted body image, only 14.9% of all subjects were the same between the subjective degree of fatness and the objective degree of fatness. 2. As a result of multiple regression, six variables were found significant($R^2=11.6%$, P < 0.01). Concerns about the weight control significantly influenced on eating disorders(EAT-26). At the same time, major(dance), wrong methods of weight control, distorted body image, prescription of M.D, and eating habits had significantly influenced on eating disorders. This results indicates that the risk of eating disorders among female dancer students was very high. Therefore, professional intervention is needed for female dance students to prevent the eating disorders.

• Archives of Plastic Surgery
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• v.37 no.4
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• pp.380-384
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• 2010

Purpose: Distinguishing different types of implants and assessing the position and size of implants by radiologic exam after orbital wall reconstruction is important in determining the surgery outcome and forecasting prognosis. We observed time-dependent density changes in three types of implants (porous polyethylene, resorbing plate and titanium mesh plate) by performing facial bone CT after orbital wall reconstructions. Methods: A total of 32 patients, who had underwent orbital wall fracture surgery from October 2006 to March 2009 and received facial bone CT as outpatients at 1 postoperative year were included in the study. Follow-up facial bone CT was performed on the patients pre- operatively, 1 month post-operatively, and 1 year post-operatively to observe the status of the orbital implants. Medpor $^{(R)}$ (Porex Surgical, Inc., Newnan, Ga.) was used as porous polyethylene and followed-up in 14 cases; for resorbing plate, Synthes mesh plate (Synthes, Oberdorf, Switzerland) was used in the reconstruction, and followed-up in 11 cases; and titanium mesh plate usage was followed-up in 7 cases. Computed tomographic scan (CT) and water's view were done for radiography, and hounsfield unit (HU) was used to compare density of those facial bone CT. Wilcoxon signed rank test was applied to statistically verify measurement difference in each group of hounsfield units. Results: Facial bone CT examination performed in 1 month post-operative showed that the density of porous polyethylene, resorbing plate and titanium mesh plate were -42.07, 105.67 and 539.48 on average, respectively. Among the three types of implants, titanium mesh plate showed the highest density due to its radiopaque feature. Following up the density of three types of implants in CT during 1 year after the orbital wall fracture surgery, the density of porous polyethylene increased in 10.52 House Field Units and the resorbing plate was decreased in 26.87 HouseField Units. There were no significant differences between densities in 1 month post-operatively and 1 year post-operatively in each group ($p{\geq}0.05$). Conclusion: We performed facial bone CT on patients with orbital fractures during follow-up period, distinguishing the types of implants by the different concentration of implant density, and the densities showed little change even at 1 year post-operative. To observe how implant densities change in facial bone CT, further studies with longer follow-up periods should be carried out.

• Journal of Chest Surgery
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• v.34 no.4
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• pp.305-310
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• 2001

배경: 판막대치술에 냉동보존판막의 이용은 감염에 대한 저항성과 탁월한 혈류역학으로 증가하고 있다. 판막육아세포의 생존율은 이식된 냉동보존 판막의 내구성에 영향을 미친다고 알려져 있고, 세포의 생존율은 warm ischemic time에 영향을 받는 것으로 알려져 있다. 냉동 보존하여 이식할수 있는 공여 판막의 warm ischemic time 의 적정치를 구하기 위하여, warm ischemic time에 다른 세포의 생존율을 관찰하였다. 대상 및 방법: 1.조직의 획득: 실제 판막을 냉동 보존하는 상황과 유사하게 하기 위하여 도살된 돼지의 심장과 폐를 밀봉한 상태로 4~8$^{\circ}C$로 냉장 보관하여 (warm ischemic time) 일정시간이 경과한 후, 심장과 폐에서 심장을 적출하여 4$^{\circ}C$하트만 용액에 24시간 보관하였다.(cold ischemic time). Warm ischemic time에 따라 2시간, 12시간, 24시간 36시간으로 4군으로 나누었으며, 각 군마다8개의 돼지 심자을 이용하였다. 2. 조직의 멸균: RRMI 1640에 항생제를 섞은 용액에 멸균하고, 3 냉동과 냉동보존; American tissue bank에서 제시한 냉동곡선에 따라 냉동하여, 액체질소 탱그에서 7일간 보존 후 해동하였다. 4. 생존율의 측정; 판막의 생존율 검사는 Triphan blue test로 하였고, 각각 warm ischemic period후 , cold ischemic period 후, 해동 후에 시행하였다. 5. 분석방법; 분석은 SAS program의 pearson correlation으로 하였다. 결과: 1. 멸균, 냉동과 냉동 보존하는 과정의 적합성을 규명하기 위하여 이 과정의 전과 후인 Cold ischemic period 후와 해동 후의 대동맥판막의 생존율의 차이를 비교한 결과, 차이가 없었다.(p =0.619). 2, warm ischemic time 과 warm ischemic period 후 , Cole ischemic period 후와 해동후의 대동맥판막의 생존율과의 correlation 은 각각 R= -0.857, -.0.673과 -0.549로 강하거나 , 혹은 뚜렷한 음성적 관계가 있었다. 삼천판막의 생존율과 대동맥판막의 생존율과 뚜렷한 상관관계가 있었다. 결론; 1. Warm ischemic time 이 길어지면 판막유아세포의 생존율이 감소하고, 12시간 이상되면 해동후의 판막육 아페포의 생존율이 50% 이하로 떨어졌다. 2. 본 연구에서 시행한 판막의 냉동보존방법은 세포의 생존율을 유지하는데 양호한 것으로 나타났으며 삼천판막으로 대동맥판막의 생존율을 예측해 볼 수 있다. 3. 그러나, 이식후 장기간 적절한 내구성을 갖기 위한 이식될 판막의 생존율은, 육아세포에 관한 여구가 좀 더 되어야 규명될 것이다.