• Nutrition Research and Practice
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• 제7권3호
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• pp.166-171
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• 2013

The purpose of this study was to investigate the effects of lotus leaf on hyperglycemia and dyslipidemia in animal model of diabetes. Inhibitory activity of ethanol extract of lotus leaf against yeast ${\alpha}$-glucosidase was measured in vitro. The effect of lotus leaf on the postprandial increase in blood glucose levels was assessed in streptozotocin-induced diabetic rats. A starch solution (1 g/kg) with and without lotus leaf extract (500 mg/kg) was administered to the rats after an overnight fast, and postprandial plasma glucose levels were monitored. Four-week-old db/db mice were fed a basal diet or a diet containing 1% lotus leaf extract for 7 weeks after 1 week of acclimation to study the chronic effect of lotus leaf. After sacrifice, plasma glucose, insulin, triglycerides (TG), total cholesterol (CHOL), high-density lipoprotein (HDL)-CHOL, and blood glycated hemoglobin levels were measured. Lotus leaf extract inhibited ${\alpha}$-glucosidase activity by 37.9%, which was 1.3 times stronger than inhibition by acarbose at a concentration of 0.5 mg/mL in vitro. Oral administration of lotus leaf extract significantly decreased the area under the glucose response curve by 35.1% compared with that in the control group (P < 0.01). Chronic feeding of lotus leaf extract significantly lowered plasma glucose and blood glycated hemoglobin compared with those in the control group. Lotus leaf extract significantly reduced plasma TG and total CHOL and elevated HDL-CHOL levels compared with those in the control group. Therefore, we conclude that lotus leaf is effective for controlling hyperglycemia and dyslipidemia in an animal model of diabetes mellitus.

• 한국주조공학회지
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• 제37권5호
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• pp.148-156
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• 2017

The effects of minor additives on the casting properties of AC4A aluminum alloys were investigated. Measurements of the cooling curve and microstructure observations were conducted to analyze the effects of Ti-B and Sr minor elements during the solidification process. A fine grain size and an increase in the crystallization temperature for the ${\alpha}-Al$ solution were evident after the addition of 0.1wt% Al-5%Ti-1%B additive. The modification effect of the eutectic $Mg_2Si$ phase with the addition of 0.05% Al-10%Sr additive was prominent. A fine eutectic $Mg_2Si$ phase and a decrease in the growth temperature of the eutectic $Mg_2Si$ phase were evident. Fluidity, shrinkage and solidification-cracking tests were conducted to evaluate the castability of the alloy. The combined addition of Al-5%Ti-1%B and Al-10%Sr additives showed the maximum filling length owing to the effect of the fine ${\alpha}-Al$ grains. The macro-shrinkage ratio increased, while the micro-shrinkage ratio decreased with the combined addition of Al-5%Ti-1%B and Al-10%Sr additives. The macro-shrinkage ratio was nearly identical, while the micro-shrinkage ratio increased with the addition of the Al-10%Sr additive. The tendency of the occurrence of solidification cracking decreased owing to the effect of the fine ${\alpha}-Al$ grains and the modification of the $Mg_2Si$ phase with the combined addition of Al-5%Ti-1%B and Al-10%Sr additives.

• 대한한방부인과학회지
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• 제15권4호
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• pp.45-60
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• 2002

생쥐의 calvarial osteoblast세포를 분리배양하여 gelatinase생성여부를 골흡수과정에서의 역할을 규명하기 위하여 SDS-PAGE-zymography분석을 한 결과 progelatinase-A를 항속적으로 합성하고 있음을 확인하였다. 생쥐의 osteoblasts를 골재흡수 약물인 PTH, $1,25(OH)_2D_3$, 단핵구배양액 (MCM) 그리고 IL-1으로 자극시키면 gelatinase생산을 촉진하여 콜라겐분해가 증가되었으나, indomethacin과 dexamethasone은 생쥐의 osteoblastic세포의 collagenolysis를 저해하였다. 한편, 골재흡수에 IL-1을 생쥐태아 유래의 장골조직배양 (fetal mouse long bone organ culture)에 처리하자 IL-1 은 골재흡수를 촉진하였다. 더우기, $IL-1{\alpha}$의 농도의존성에 대한 indomethacin과 dexametasone의 영향을 검토한 결과 직선형의 비례커브로 영향을 미쳤다. 이러한 골대사의 지견을 바탕으로 대영전-자하거의 열수추출물의 시험관내 독성검사에서 $1-200\;{\mu}g/ml$의 농도에서는 독성이 없었으며, 또한, $300\;{\mu}g/ml$ 농도에서도 생쥐의 calvarial골에는 독성이 없었다. 대영전-자하거 extract는 PTH (2 units/ml), MCM (5%, v/v), $rhIL-1{\alpha}$ (1 ng/ml) $1,25(OH)_2D_3$ (10 ng/ml)처리에 대해서 그리고 $IL-1{\alpha}$와 $IL-1{\beta}$-유발 collagenolysis에 대해서도 보호효과가 있었다. 대영전-자하거extract을 1시간동안 전처리와 후처리에서 콜라겐분해에 약간의 보호활성이 있었으며 $IL-1{\alpha}$와 $IL-1{\beta}$에 의해 유발되는 콜라겐분해에 보호활성이 보였다. 1시간동안 전처리는 콜라겐분해를 감소시키며, 대영전-자하거 extract는 gelatinase효소를 저해하였으며 PTH, $1,25(OH)_2D_3$, $IL-1{\beta}$ 및 $IL-1{\alpha}$로 유발된 효소활성화가 저해되었다. 즉, 대영전-자하거 extracts는 $IL-1{\alpha}-$와 $IL-1{\beta}$에 의해 촉진되는 골재흡수에 효과적이었으며, 비스테로이드성 항염증제제 (indomethacin 과 dexamethasone)에 의한 골재흡수방지 효과와 유사하였다. 이러한 결과는 대영전-자하거extract가 골다공증치료에 효과적임을 나타내는 것이다.

• 한국식품영양과학회지
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• 제38권11호
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• pp.1528-1534
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• 2009

구기자는 식용가능하고 제2형 당뇨병 합병증인 지방간분해, 고혈압 및 고혈당에 효능이 있다고 알려져 있다. 하지만 당 대사 및 지질 대사에 작용하는 정확한 기작에 대한 연구는 아직 미비하기에 탄수화물 소화효소인 ${\alpha}$-amylase와 ${\alpha}$-glucosidase의 저해활성 및 정상생쥐를 이용한 혈당강하 효과와 3T3-L1 adipocyte를 통하여 비만축적 억제효과를 보았다. 구기자 추출은 80% MeOH, 70% EtOH 및 열수추출하였으며 이들 중 ${\alpha}$-amylase 50% 저해 활성($IC_{50}$)은 saliva ${\alpha}$-amylase에서 acarbose, 80% MeOH, 70% EtOH, aqueous(7.04, 3.19, 3.20, 3.66 mg/mL), pacreas ${\alpha}$-amylase acarbose, 80% MeOH, 70% EtOH, aqueous(10.97, 4.16, 3.07, 3.55 mg/mL)로 saliva ${\alpha}$-amylase에선 acarbose보다 80% MeOH, 70% EtOH 추출물이 가장 낮은 농도에서 $IC_{50}$값을 나타냈고 pacreas ${\alpha}$-amylase에서는 70% EtOH 추출물이 가장 낮은 농도에서 $IC_{50}$값을 나타냈다. 또한 10 ${\mu}g/mL$ 농도에서 yeast ${\alpha}$-glucosidase 활성저해 $IC_{50}$값은 80% MeOH, 70% EtOH, aqueous(5.01, 4.98, 4.80 ${\mu}g/mL$)로 구기자 추출물 모두 acarbose(5.05)보다 우수한 $IC_{50}$값을 나타냈다. 정상생쥐에게 탄수화물 소화효소의 저해활성이 높은 70% EtOH 추출물을 전분과 함께 경구투여 한 후 내당능을 측정한 결과, 전분과 함께 100, 200 mg/kg body weight를 경구투여 한 경우, 대조군에 비해 투여 후 30, 60, 90, 120분에 혈당 증가가 낮았다. 또한 추출물을 100 mg보다 200 mg 투여하였을 경우 대조군에 비해 각각 19% 및 40%씩 저하되었으며, 120분에는 대조군 수준이 되었다. 그리고 3T3-L1 adipocyte에서 비만축적 억제효과를 측정한 결과 70% EtOH 추출물 농도가 증가함에 따라 leptin, 중성지방 농도가 감소하였고 유리지방산 농도는 증가하였다. 이상의 연구 결과 구기자 추출물 중 70% EtOH는 acarbose보다 높은 ${\alpha}$-glucosidase, ${\alpha}$-amylase 저해활성을 나타냈으며, 정상생쥐를 통해 식후 혈당증가를 저하시키는 효과를 확인하였고 GLUT4 발현 역시 증가함을 확인했다. 이를 통해 구기자 추출물이 지방축적 억제와 인슐린 저항성 억제 및 혈당강하 기전을 확인하여 제2형 당뇨병 개선에 효과적인 것으로 판단, 추후 더 연구하여 보다 더 정확한 성분을 조사할 필요성이 있다고 사료된다.

• Nutrition Research and Practice
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• 제4권2호
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• pp.99-105
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• 2010

Obesity is considered a mild inflammatory state, and the secretion of inflammation-related cytokines rises as adipose tissue expands. Inflammatory cytokines, including tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interlukin 6 (IL-6) and monocyte-chemoattractant protein 1 (MCP-1), are modulated by adipose tissue and known to play an important role in insulin resistance which is the common characteristics of obesity related disorders. In this study we analyzed the effects of Sasa borealis leaves extract on inflammatory cytokines and insulin resistance in diet induced obese C57/BL6J mice. The obese state was induced by a high fat diet for 20 weeks and then the mice were divided into two groups; obese control group (OBC, n = 7) and experimental group (OB-SBE, n = 7). The OBC group was fed a high fat diet and the OB-SBE group was fed a high fat diet containing 5% Sasa borealis leaves extract (SBE) for 12 weeks. We also used mice fed a standard diet as a normal control (NC, n = 7). The body weight and adipose tissue weight in the OB group were significantly higher than those in the NC group. The effects of the high fat diet were reduced by SBE treatments, and the body weight and adipose tissue deposition in the OB-SBE group were significantly decreased compared to the OBC group. The OBC group showed higher serum glucose and insulin levels which resulted in a significant increase of incremental area under the curve (IAUC) and HOMA-IR than the NC group. Also, serum leptin, TNF-${\alpha}$, and IL-6 levels were significantly higher in the OBC group than in the NC group. In contrast, the OB-SBE group showed a reversal in the metabolic defects, including a decrease in glucose, insulin, IAUC, HOMA-IR, TNF-${\alpha}$, IL-6 and leptin levels. These results suggest that BSE can suppress increased weight gain and/or fat deposition induced by a high fat diet and theses effects are accompanied by modulation of the inflammatory cytokines, TNF-${\alpha}$ and IL-6 secretion resulting in improved insulin resistance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1102-1104
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• 1995

This study presents the results of an investigation on the electrical characteristics of $PVF_2$ film, to be regarded as the excellent piezo and pyroelectricity, using dielectric relaxation technique by the variation of temperature and frequency. As one of the results, we confirmed that crystal form with Infrared absorption and XRD was ${\alpha}$ type and its crystalline was 59[%]. Also, the results of observation conformed to Debye theory for frequency variation of relative permitivity and dielectric relaxation. Especially, we confirmed each constant values in comparision with equation related to diffusion behavior of ion, so we obtained that activation energy was computed 17.25[kcal/mole] from the relation curve with frequency and temperature.

• 한국간호교육학회지
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• 제21권2호
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• pp.215-226
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• 2015

Purpose: This study aimed to develop a self-assessment tool to evaluate program outcomes of nursing students in Korean nursing undergraduate education. Methods: The instrument development process consisted of literature review, focus group interviews, and item validation. A total of 117 items were analyzed through content validity testing. Data was gathered from 302 nursing students in Korea and analyzed using SPSS 21.0. Results: To construct validity, principal component analysis and Varimax rotation were used, and 12 factors, with a cumulative explanatory variance of 69.16%, were determined from 79 items. For internal consistency and reliability, Cronbach's ${\alpha}$ was .91. The half-split reliability results were .84 and .85, and the ROC curve showed an optimal cutpoint at 227. A five-point Likert scale was used for scoring. Conclusion: This instrument was found to have fair validity and reliability as a self-assessment tool for nursing student learning outcomes. Therefore, it can be used to evaluate program outcomes indirectly in nursing schools.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1646-1651
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• 2004

This paper has been carried out to find the thermal efficiency and operating characteristics of heatpipe type solar collector using a glass concentric evacuated tube(CETC) during summer. In an experiment the flow rate of water in collector are 1.5l/min. Collector efficiency is $50{\sim}60%$ during time. The solar radiation appeared in a clear day is efficiency high. Efficiency curve fitted first order polynomial show that $F_{R}$$({\tau}{\alpha})$ and $F_{R}U_{L}$=1.316 is 0.601 and 1.316 respectively.

• 한국진공학회지
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• 제10권4호
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• pp.411-415
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• 2001

대기압 저온 플라스마를 사용하여 산화아연 박막의 건식 식각 가능성을 연구했다. 플라스마로부터 $H_\alpha^*$과 $CH_^*$ 라디컬 발생을 확인하였고, 라디컬 발생 능력은 광학 발광 스펙트럼 및 플라스마 임피던스 분석에 의해 캐소드 전극에 의존하는 것을 알았다. 식각능력은 플라스마 I-V커브에 의한 임피던스와 발광강도에 의해 계산되었다.

• Journal of Nutrition and Health
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• 제20권2호
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• pp.83-89
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• 1987

This study was conducted to investigate the effect of repeated blood collection on the amount of vitamin E in serum and liver of the rats fed standard diet. Rats (Sprague Dawley strain) were fed standard were fed standard diet for several weeks. Blood was collected with on improved cardiac puncture method at regular intervals . The amount of vitamin E analogs were measured by the HPLC. 1) The growth curve of all groups was normal, but bodyweight gains of group II were significantly decreased in case of 7 week- rats whose blood was collected at intervals of two weeks. 2) The amount of vitamin E analogs in serum of rats during growth increased, but continuos blood collection could not affect on the amount of vitamin E in serum. Especially, in the group I serum vitamin E equivalent were significantly higher in case of 7 weeks than first week. 3) The amount of liver vitamin E analogs were changed irregularly, and especially, $\alpha$-Tocopherol equivalent were significantly higher in group II then other groups.