• 대한핵의학회지
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• 제35권4호
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• pp.258-267
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• 2001

Purpose/Methods: Repeated administration of methamphetamine (METH) produces high extracellular levels of dopamine (DA) and subsequent striatal DA terminal damage. The effect of MK-801, a noncompetitive N-methyl-D-aspartate receptor antagonist, on METH-induced changes in DA transporter (DAT) and DA release evoked by an acute METH challenge was evaluated in rodent striatum uslng $[^3H]$]WIN 38,428 ex vivo auto-radiography and in vivo microdialysis. Results: Four injections of METH (10 mg/kg, i.p.), each given 2 h apart, produced 71% decrease in DAT levels in mouse striatum 3 d after administration. Pretreatment with MK-801 (2.5 mg/kg, i.p.) 15 min before each of the four METH injections protected completely against striatal DAT depletions. Four injections of MK-801 alone did not significantly change striatal DAT levels. Striatal DA release evoked by an acute METH challenge (4 mg/kg, i.p.) at 3 d after repeated administration of METH in rats was decreased but significant compared with controls, which was attenuated by repeated pretreatment with MK-801. Also, repeated injections of MK-801 alone attenuated acute METH-induced striatal DA release 3 d after administration. Conclusion: These results suggest that repeated administration of MK-801 may exert a preventive effect against METH-induced DA terminal injury through long-term attenuation of DA release induced by METH and other stimuli.

• Korean Journal of Acupuncture
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• 제35권3호
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• pp.139-148
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• 2018

Objectives : This study was performed to examine the toxicity on the long term procedure of Aconitum ciliare Decaisne pharmacopuncture(ADP) solution. Methods : To evaluate the long term toxicity of 3 different repeated doses, 60, 150, and 300 mg/kg/day for 13 weeks were injected into BALB/c mice, respectively. The ADP solution was injected into near ST36 of the right leg and normal saline of the same volume was used for the vehicle control group. To evaluate the toxicity of 60, 150, and 300 mg/kg of repeated doses for 13 weeks, toxic symptoms, weight measurement, hematological test, blood biochemical test, visual examination and weight measurement of major organs, and histopathological test were conducted. Results : No significant changes in toxic symptoms, weight measurement, hematological test, blood biochemical test, visual examination and weight measurement of major organs, and histopathological test were observed in different doses of ADP solution treated groups compared to vehicle control group. Conclusions : As a result, repeated dose at a concentration of 300 mg/kg or less is considered to be not harmful for clinical treatment.

• 대한본초학회지
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• 제32권1호
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• pp.63-68
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• 2017

Objectives : HT042 is a combination of three herbal extracts from the roots of Astragalus membranaceus, the stems of Eleutherococcus senticosus and the roots of Phlomis umbrosa, which has been demonstrated to increase longitudinal bone growth rate. The aim of this study was to assess the safety of HT042 after repeated oral administration. Methods : A 14-day repeated oral dose toxicity study was conducted using male and female Sprague-Dawley rats. HT042 was administered orally at repeated doses of 500, 1,000 and 2,000 mg/kg/day for 14 days. Clinical signs and mortality were observed daily, whereas body weight and food consumption were recorded weekly throughout the experiment. At the end of the study, blood was taken from the posterior vena cava for hematology and serum biochemistry. All organs of the body surface, subcutis, head, thoracic cavity, and abdominal cavity were observed grossly. Then, the internal organs were removed and weighed. Results : No death occurred and no significant changes in clinical sign, body weight, food consumption and serum biochemistry parameters were observed in male and female rats over the study period. Although there were some alterations in hematologic and necropsy findings, and organ weights, these changes were not considered toxicologically significant. Conclusions : These results suggest that the 14-day repeated administration of HT042 does not produce any significant oral toxicity at doses of up to 2,000 mg/kg/day in male and female rats under the present experimental conditions.

• 대한화장품학회지
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• 제39권2호
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• pp.105-115
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• 2013

국내의 주름개선 혹은 미백 효능을 평가하기 위한 인체시험 방법은 식약청 가이드라인에 근거하여 시행 되어왔으며, 인체시험에서 육안평가 및 기기평가 결과에 대해 시험군과 대조군 간의 효과를 비교하기 위해서 unpaired t-test를 주로 이용하였고, 시술 전후의 효과를 비교하기 위해서 paired t-test를 이용하였다. 설문평가 결과에 대해서는 빈도분석을 이용한 기술통계법이 이용되고 있다. 미국 및 유럽의 임상 평가기관에서도 이와 유사한 시험법 및 통계분석 방법을 이용하고 있다. 그러나 동일 개체에 대하여 처치를 반복 적용하여 얻은 자료는 서로 관련성이 높아 이를 감안한 분석법을 적용해야 한다. 따라서 본 연구에서는 화장품 분야에서는 처음으로 기능성 화장품 중 주름 개선 및 미백 효능 시험의 육안평가 및 기기평가 자료에 대해 repeated measures ANCOVA (RM ANCOVA)와 repeated measures ANOVA (RM ANOVA)를 적용하여 통계 방법의 타당성 여부를 검증함으로서 현재의 인체시험 방법에 적합한 새로운 통계분석 방법을 제시하였다.

• Molecules and Cells
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• 제38권12호
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• pp.1071-1078
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• 2015

Superovulation induced by exogenous gonadotropin treatment (PMSG/hCG) increases the number of available oocytes in humans and animals. However, Superovulatory PMSG/hCG treatment is known to affect maternal environment, and these effects may result from PMSG/hCG treatment-induced oxidative stress. 2-Cys peroxiredoxins (2-Cys Prxs) act as antioxidant enzymes that protect cells from oxidative stress induced by various exogenous stimuli. Therefore, the objective of this study was to test the hypothesis that repeated PMSG/hCG treatment induces 2-Cys Prx expression and overoxidation in the reproductive tracts of female mice. Immunohistochemistry and western blotting analyses further demonstrated that, after PMSG/hCG treatment, the protein expression levels of 2-Cys Prxs increased most significantly in the ovaries, while that of Prx1 was most affected by PMSG/hCG stimulation in all tissues of the female reproductive tract. Repeated PMSG/hCG treatment eventually leads to 2-Cys Prxs overoxidation in all reproductive organs of female mice, and the abundance of the 2-Cys Prxs-$SO_{2/3}$ proteins reported here supports the hypothesis that repeated superovulation induces strong oxidative stress and damage to the female reproductive tract. Our data suggest that excessive oxidative stress caused by repeated PMSG/hCG stimulation increases 2-Cys Prxs expression and overoxidation in the female reproductive organs. Intracellular 2-Cys Prx therefore plays an important role in maintaining the reproductive organ environment of female mice upon exogenous gonadotropin treatment.

• 한국진공학회지
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• 제7권4호
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• pp.306-313
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• 1998

전기적 착색 텅스텐산화물 박막이 전자비임 증착법에 의해 제작되었다. 전자비임에 의한 막의 퇴화에 미치는 영향이 논의되었다. 진공도 $10^{-4}$mbar에서 제작된 막이 사이클 내 구성 시험에 의한 결과, 가장 안정하였다. 황산 수용액에서 막의 퇴화는 진공도에 의존함을 보였다. 막두께는 산화와 환원전류 그리고 광학적 특성에 큰 영향을 미쳤다. 박막들 중에서 두께 5,000$\AA$의 시료가 사이클에 의한 내구성이 가정 안정하였다. 착색과 탈색이 반복되는 동안에 막의 퇴화의 근원은 막속에 이온의 누적 때문이며, 이로인해 산화와 환원전류가 감 소하였다. 티타늄의 양이 약10~15mol% 함유된 텅스텐산화물 박막은 착색과 탈색사이클이 반복되는 동안 최소한의 퇴화가 일어나서 가정 안정하였다. 사이클이 반복되는 동안 최소한 의 막 퇴화의 주 원인은 막속에 리튬이온의 포획위치 개수의 감소에 있었으며 이로인해 막 의 내구성이 증가하였다.

• 한국수정란이식학회지
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• 제12권1호
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• pp.37-48
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• 1997

I. The Factors Influencing In Vivo Embryo Production by Condition of Superovulation Treatment These studies were carried out to establish an effective and practical system for comrnercialization of embryo production techniques by analyzing several factors influencing in vivo embryo production on superovulation treatment in Korean native cattle. In vivo embryos were flushed 226 times from 128 donors.The results obtained from the studies on the factors influencing in vivo embryo production by superovulation treatment were as follows : FSH-P had a significiant advantage(83.0%) over SUPER-OV in the percentage of fertilized embryos(P<0.01). No difference was found loetween FSH-P and SUPER-OV in the percentage of transferable and freezable embryos.2. The response of superovulation by SUPER-OV was greater than that of FSH-P The donors having 8~9 and more than 10 of corpora lutea(CL) derived by FSH-P were 40.0%(most frequent) and 33%, respectively. The donors having more than 12 and 10 CL derived by SUPER -OV were 33.3% (most frequent) and 56.6%, respectively.3. Embryo production after treatment of repeated superovulation was remarkablely decreased at 3rd time by FSH-P but did not differ among 1, 2 and 3rd times by SUPER-OV. Embryo production on intervals of repeated superovulation was significantly different for the number and percentage of fertilized, transferable and free-zable' embryos in FSH-P (P<0.01) and rernarkablely decreased in repeated superovulation of 81~120 interval days. The SUPER-OV showed no differences in interval days of repeated superovulation and was found better than FSH-P in the response of repeated superovulation. (Key words : in Vivo embryo, superovulation, FSH -P, SUPER-OV)

• 응용통계연구
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• 제28권2호
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• pp.201-210
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• 2015

생명과학 또는 의학 연구에서는 반복 측정된 변수들 간의 상관 관계를 보고자 하는 경우가 발생한다. 반복 측정된 것을 고려하지 않으면 상관관계를 과소 추정하는 경향이 나타나므로 이를 고려해야 하며, 선형혼합모형의 분산-공분산 행렬을 이용하여 상관관계를 추정할 수 있다. 본 연구에서는 변수들의 반복 측정이 동시에 된 경우와 그렇지 않은 경우로 나누어 혼합모형을 이용한 상관계수의 추정방법을 소개한다. 고속 음향 복사력 임펄스 영상(acoustic radiation force impulse imaging; ARFI)으로 간과 비장에서 각각 세 번씩 전단파 속도를 반복 측정하고 복부 초음파 검사로 비장 길이를 측정한 자료에서 전단파 속도와 비장 길이 간의 상관 관계를 분석하기 위해 본 논문에서 소개한 방법들을 적용하였고 SAS의 PROC MIXED를 이용하는 방법을 제시하였다.

• Toxicological Research
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• 제21권3호
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• pp.263-269
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• 2005

This study was performed to investigate repeated-dose toxicities of Clean natural, a new disinfectant, in Sprague-Dawley(SD) rats. In the 4-week repeated oral toxicity study, Clean Natural was orally administered once daily via gavage to male and female rats at dose levels of 0, 500, 1,000 and 2,000 mg/kg body weight for 4-weeks. There were no deaths and clinical signs during the dosing period. In both sexes, there were no statistically significant differences between the administered and control groups in urinalysis indicators and hematological parameters. In serum biochemistry, aspartate aminotransferase(AST) was significantly decreased and sodium content was increased in the 2,000 mg/kg male group, while chlorine was significantly decreased in the 2,000 mg/kg female group. Also, albumin, total cholesterol and total bilirubin were significantly increased in the 2,000 mg/kg male and female group. In histopathological examinations, centrilobular hepatocellular hypertrophy in the liver was observed in the 2,000 mg/kg male and female groups. And pigmentation in the spleen was observed in the 2,000 mg/kg male group. In conclusion, four-week repeated oral dose of Clean Natural to rats did not cause apparent toxicological change at the dose less than 2,000 mg/kg body weight. Thus it is suggested that no-observed adverse-effect level(NOAEL) for Clean Natural in rats was considered to be 1,000 mg/kg/day.

• Electronic Materials Letters
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• 제14권6호
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• pp.678-688
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• 2018

The repeated-bending properties of Sn-0.7Cu, Sn-0.3Ag-0.7Cu (SAC0307), and Sn-3.0Ag-0.5Cu (SAC305) solders mounted on flexible substrates were studied using highly accelerated stress testing (HAST), followed by repeated-bending testing. In the Sn-0.7Cu joints, the $Cu_6Sn_5$ intermetallic compound (IMC) coarsened as the HAST time increased. For the SAC0307 and SAC305 joints, the $Ag_3Sn$ and $Cu_6Sn_5$ IMCs coarsened mainly along the grain boundary as the HAST time increased. The Sn-0.7Cu solder had a high contact angle, compared to the SAC0307 and SAC305 solders; consequently, the SAC0307 and SAC305 solder joints displayed smoother fillet shapes than the Sn-0.7Cu solder joint. The repeated-bending for the Sn-0.7Cu solder produced the crack initiated from the interface between the Cu lead wire and the solder, and that for the SAC solders indicated the cracks initiated at the surface, but away from the interface between the Cu lead wire and the solder. Furthermore, the oxide layer was thickest for Sn-0.7Cu and thinnest for SAC305, regardless of the HAST time. For the SAC solders, the crack initiation rate increased as the oxide layer thickened and roughened. $Cu_6Sn_5$ precipitated and grew along the grain and subgrain boundaries as the HAST time increased, embrittling the grain boundary at the crack propagation site.