• Journal of Nutrition and Health
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• 제31권9호
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• pp.1377-1384
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• 1998

본 연구에서는 streptozotocin으로 당뇨를 유발시킨 횐쥐에게 methanol로 추출하여 분획한 참마의 $H_2O$ 분획물을 경구투여하고 selenium은 식이로 보충하여 당뇨시 14일간 혈당과 지질대사에 미치는 영향을 실험하여 다음과 같은 결과를 얻었다. 당뇨대조군은 당뇨로 인한 대사상의 변화로 정상군과는 다른 대사적인 차이를 나타내었다. 전 실험 기간 중 횐쥐의 체중변화는 정상군에 비해 당뇨실험군 모두에서 유의적으로 감소되었으며 DJT-Se군에서 다른 당뇨실험군보다 적은 양의 체중감소를 보였다. 참마와 Se 보충식이에 따른 식이효율도 DJT-Se군에서 유의적인 차이는 아니었지만 다른 당뇨실험군에 비해 높았다. 장기 의 무게를 체중 100g당으로 환산하였을 때 간장과 신장의 무게는 정상군보다 유의적으로 비대해졌으며 비장은 당뇨실험군 모두에서 정상군보다 무게가 낮게, 췌장은 높게 나타났다. 혈장 포도당 수준은 당뇨실험군 중 DJT-Se군에서 유의적으로 낮아졌으며 인슐린의 함량 수준은 당뇨실험군 간의 유의적인 차이를 보이지 않았으나 DJT-Se군에서 약간 높았다. 혈장단백질 수준은 당뇨대조군에 비해 당뇨실험군 모두에서 높게 나타났다. 혈장 지질 수준에 미치는 영향을 보면 혈장 cholesterol의 경우 당뇨대조군과 당뇨실험군 간의 큰 차이는 없었으나 당뇨실험군에서 낮은 경향을 보였다. HDL-cholesterol 수준은 모든 당뇨실험군에서 높게 나타났다. 중성지방의 경우는 DJT-Se군과 Se군에서 유의적으로 낮은 수준이었다. 유리지방산 함량은 정상군과 당뇨실험군 사이에 차이를 보이지 않았다. AST와 ALT 활성도는 군 간에 큰 차이를 보이지 않았으나 당뇨대조 군에 비해 DJT군에서는 유의성을 보였다. 본 연구 결과 참마나 Se를 독립적으로 섭취하는 것 보다는 병용하여 보충하는 것이 항산화 작용의 상승효과를 보여주어 고혈당과 지방대사산물에 작용하여 혈당강하효과를 보일 것으로 생각된다. 참마의 혈당강하에 영향하는 생리활성성분과 Se보충에 의한 대사적인 변화에 대하여 더 구체적인 생화학적인 연구가 이루어져야 될 것으로 여겨진다.

• Nutritional Sciences
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• 제6권2호
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• pp.85-93
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• 2003

The purpose of this study was to investigate the effects of a butanol fraction of fraction of Alisma canaliculatum All. Braun et Bouche (Ac), and of selenium (Se), on plasma gllucose and lipid levee in streptozotocin (STD-induced diabetic rats. Male Sprague-Dawley rats, fed the AIN-93 recommended diet, were divided into five groups: a non-diabetic control group (no STZ treatment), and four 572-induced diabetic groups which consisted of a diabetic-control group, an Ac-treated group, an Ac-Se treated group, and a Se-treated group. Diabetes was induced in the rats by an injection of STZ into the tail vein at a dose of 45 mg/kg body weight. The butanol (BuOH) fraction of Ac was orally administered at a rate of 400 mg/kg body weight for 21 days to both the Ac and Ac-Se groups. The supplementation of selenium in the Se and Ac-Se groups was achieved by adding (freshly, every day) 2 mg of Se as Na$_2$SeO$_3$ per kg of feed. The rats'body weights and hematocrit (Hct) levels were measured, along with plasma levels of glucose, insulin, cholesterol, HDL-cholesterol, triglyceride (TG), and free fatty acids (FFA). Aminotransferase activities were also analyzed. The non-diabetic rats gained weight, while the diabetic rats lost weight - except in the Ac-Se group, which maintained their initial weight. The blood glucose levels of the Ac group and the Se group were significantly lower than for the diabetic-control group. The plasma triglyceride levels were lowered when both Ac and Se were administered to diabetic rats. The concentrations of plasma FFA in the Ac-Se group were significantly lower compared with the diabetic-control group. Plasma cholesterol levels and alanine aminotransferase activity in the Ac, Ac-Se, and Se groups were significantly lower when compared with the diabetic-control group. Aspartate aminotransferase activity was significantly lower in the Se group compared to the other diabetic groups. These data show that treatment with a butanol fraction of Ac in combination with Se has no synergistic effect. Plasma glucose levels tended to be low when Se was administered to diabetic rats. Supplementation of Se in diabetic rats did not elicit a significant increase in plasma insulin levels or result in hypolipemic effects.

• 한국세라믹학회지
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• 제44권4호
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• pp.194-197
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• 2007

Polyacrylonitrile (PAN)/$Fe_2O_3$ nanocomposite membranes with a thickness of 0.02 mm were electrospun by adding 0 to 5 wt% of $Fe_2O_3$ into PAN. The surface tension, density, kinematic viscosity and dynamic viscosity of the PAN solution were determined to be $33.8{\pm}1mN/m$, 0.9794 g/ml, $1548.6mm^2/sec$ and 1516.7 cP, respectively. The average diameters of PAN fibers containing 0, 1 2, 3, and 4 wt% $Fe_2O_3$ particles were 300, 260, 210, 130, and 90 nm, respectively. Fourier-transform infrared spectroscopy results showed that the addition of $Fe_2O_3$ nanoparticles to the PAN mat reduced the absorption peak intensity at $2242cm^{-1}$ ($C{\equiv}N$ bond) while it caused a sharp increase in the peak intensity at $2356cm^{-1}$(C=O bond). Thus, it appears that an appropriate amount of $Fe_2O_3$ nanoparticles in the PAN backbone leads to an improvement of the performance of the $CO_2$ gas sensor, most likely due to the change of functional groups in the membrane.

• Preventive Nutrition and Food Science
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• 제12권1호
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• pp.35-39
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• 2007

This study was conducted to investigate the effects of soil selenium (Se) supplementation level on Se contents of green tea and milk vetch. Four different concentrations of sodium selenite ($Na_2SeO_3$) solutions (0.0, 3.3, 33.0 and 165.0${\mu}g/mL$) were prepared and one liter of each solution was well mixed with 10 kg of compost (cowpea soil) to give four different levels of Se-containing soil: $T_1$, 0; $T_2$, 33; $T_3$, 330; $T_4$, and 1,650${\mu}g$/100 g soil. Green tea plants and milk vetch were individually cultivated in those soils for 60 days. Se contents of freeze-dried green tea leaves were 6.87, 10.40, 12.04, and 20.19 ${\mu}g/g$, respectively; all of which were significantly different (p<0.05) from the others except for $T_2$ and $T_3$. The results showed that Se-contents of green tea leaves were increased 1.5$\sim$2.9 times as the Se level in the soil increased. Regression equation between Se contents in green tea (Y) and soil Se supplementation level (X) was: Y=0.007X＋8.857. However, Se contents in the milk vetch were increased significantly (p<0.05) more with the same treatments $T_3$ (74 ${\mu}g/g$) and $T_4$ (187$\mu$g/g) in comparison to those at $T_1$ (5.0 ${\mu}g/g$) and $T_2$ (12.0$\mu$g/g). The increases ranged from approximately between 2.4 to 37.4 times that of the control group. Regression equation between Se contents in milk vetch (Y) and soil Se supplementation level (X) was: Y=0.1063X＋15.989. The large difference of Se contents between green tea leaves and milk vetch would be attributed by the difference of protein contents between the 30% or higher protein-content of legumes and 15$\sim$20% protein of shrubs. The present study clearly indicates that green tea leaves and milk vetch can be enriched in selenium by supplementing the soil with Se. Therefore, Se-enriched green tea or milk vetch powder could be utilized as functional foods in Se-fortified green tea drinks or salads, or as food additives to enhance the daily intake of Se.

• 한국해양공학회지
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• 제9권2호
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• pp.141-148
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• 1995

Fatigue tests were carried out by a rotary bending testing machine of cantilever type. M.E.F.(ferrite encapsulated islands of martensite) materials were made by a series of heat treatment from a low carbon steel(SM 20 C). The fatigue tests were conducted at stress levels of 302 MPa and with frequencies of 25Hz, 2.5 Hz and 0.5 Hz in 3% NaCl solution. The fatigue strength increased with frequency got higher. The microcracks and corrosion pits were generated at the boundary between the matrix and the 2nd phase. The cracks generated by the corrosion pits were coalesced with the pits around the notch and became the initial crack. The $N_i/N_f$ ratio increased as the frequency and stress level decreased. The interference phenomenon increased with stress level and frequency gots higher. The crack propagation rate was delayed as the stress level lowers and the frequency gets higher, however, the range of the stress intensity factor depended only on a stress level.

• Journal of Nutrition and Health
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• 제37권1호
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• pp.15-22
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• 2004

The purpose of this study was to investigate the effect of butanol (BuOH) fraction of Alisma canaliculatum (Ac) and/or selenium (Se) treatment on glycogen level, lipid metabolism and lipid peroxidation in streptozotocin (STZ)-induced diabetic rats. Male Sprague-Dawley rats were assigned to one of the five groups: normal, STZ-control, and three experimental groups (Ac group, Ac-Se group, and Se group). Diabetes was experimentally induced by intravenous administration of 45 mg/kg of STZ in citrate buffer. The BuOH fraction of Ac (400 mg/kg bw) was orally administered for 3 weeks. The Se group were fed a AIN-93 recommended diet mixed with Na$_2$SeO$_3$ (2 mg/kg diet). The liver glycogen level of Ac and Ac-Se groups were significantly higher, when compared with the STZ-control groups. The muscle glycogen level was not significantly differ among all groups. The levels of liver triglyceride were higher in Ac-Se group than the STZ-control group. Pancreas protein levels were significantly increased in Ac-Se group than STZ-control group. The concentration of liver malondialdehyde (MDA) was significantly decreased in Ac and Se groups and decreased in Ac-Se group. Administration of BuOH fraction of Alisma canaliculatum and selenium supplementation increased the liver glycogen and triglyceride levels, and reduced peroxidative liver damage in STZ induced diabetic rats. These results suggest that treatment with a BuOH fraction of Alisma canaliculatum in combination with selenium has no synergistic antioxidative effect. Selenium supplementation may lead a decrease MDA of liver in diabetic rats.

• Journal of Animal Science and Technology
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• 제47권2호
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• pp.305-316
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• 2005

This study was conducted to determine the total amount and type of seleniwn (Se) in the Se-enriched mushroom and its spent mushroom composts (SMC), and to investigate the metabolism in relation to Se accwnulation in the mushroom. Mushrooms, Flammulina velutipes, used in this study were grown for 60 days by adding 2 rng of inorganic Se (Na2Se03) per kg of mushroom composts (MC) on as-fed basis and were compared with normal mushrooms grown on the non Se-supplemented Me. Total Se contents for Se-treated mushrooms were significantly increased (P < 0.0001) by 20-fold (4.51 $\mu$/ g of dry) compared to Se-untreated (0.23 $\mu$/ g of dry). On the contrary, organic Se ratio was significantly lower (P < 0.0001) in the Se-treated mushroom (72.3 %) than the Se-untreated one (100 %, not analytically detected of inorganic Se). Se distribution upon a length in the Se-treated mushrooms was the highest in the bottom part (6.86 $\mu$/ g of dry) near to MC, and top and middle parts were significantly lower (3.71 and 3.01 $\mu$/ g of dry, respectively; P < 0.001) than the bottom. In the SMC from Se-treated mushrooms, the significant amount of Se (5.04l1g/g of dry) was remained, but that from the Se-untreated mushrooms was significantly low (P$\mu$ / g of dry. Se-treated SMC showed a high ratio of organic Se (65.67 %), suggesting that the significant amount of inorganic Se in the SMC was converted to organic Se by mushroom mycelia. Prior to mycelia inoculation in the mushroom culture, the sterilization of MC brought approximately 18% of Se loss in the MC. Apparent and net accumulation rates (%) for Se into mushrooms were 14.81 and 10.14 %, respectively, resulting from the Se volatilization into the air via metabolic process of mushroom itself. The result of this study shows that inorganic Se addition to MC for mushroom improved the organic Se contents in the mushroom and SMC. This study showed the possibility that Se in Se-enriched mushroom and SMC could be utilized as Se sources of food for human as well as feed for livestock.

• Transactions on Electrical and Electronic Materials
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• 제10권4호
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• pp.121-124
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• 2009

In this study, in order to develop compositions of ceramics suitable for piezoelectric actuator and ultrasonic vibrator applications using low temperature sintering, multilayer, PMN-PNN-PZT ceramics were fabricated using $Li_2CO_3$ and $Na_2CO_3$ as sintering aids. Their structural, piezoelectric and dielectric characteristics were investigated according to the Zr/Ti ratio. As the Zr/Ti ratio increased, the electromechanical coupling factor $k_p$, and piezoelectric constant $d_{33}$ and the mechanical quality factor $Q_m$ all increased with Zr/Ti ratio and then decreased after the ratio exceeded 50/50. At the ratio of Zr/Ti =49/51 and sintering temperature of $900^{\circ}C$; the density, electromechanical coupling factor $k_p$, dielectric constant ${\varepsilon}_r$ piezoelectric $d_{33}$ constant and mechanical quality factor $Q_m$ all showed the optimum values of 7.900 $g/cm^3$, 0.576, 856, 312 pC/N, 1,326, respectively. These property values are very suitable for multilayer ceramics actuator applications.

• 생물환경조절학회지
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• 제16권3호
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• pp.180-185
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• 2007

셀레늄과 게르마늄 처리 시 배추(봄, 가을배추)와 고추의 생육과 품질의 변화를 조사하였다. 셀레늄처리에 의한 봄배추와 가을배추의 생체중은 차이가 없었고 Ge 처리시 높은 농도에서 생체중이 감소하였으나 고추에서는 차이가 없었다. 배추의 셀레늄 처리 경우 비타민 C 함량은 Se $4mg{\cdot}L^{-1}$ 10회 처리가 무 처리에 비하여 증가하였으며 게르마늄 처리 경우 Ge $4mg{\cdot}L^{-1}$ 10회 처리와 Ge $8mg{\cdot}L^{-1}$ 5회 처리에서 증가하였다. 고추에서 셀레늄 처리에 의해 Se $2mg{\cdot}L^{-1}$ 20회 처리가 높았으며 홍고추가 풋고추에 비교하여 비타민 C 함량이 약 2배가량 많았다. 봄, 가을배추 부위별 셀레늄함량은 외엽>중엽>내엽 순으로 많았고 엽육부위가 중륵에 비해 높았으며 농도의 증가에 따라 증가하는 경향이었다. 게르마늄 처리 시 가을 배추 잎에서 모든 처리구가 무 처리에 비해 높았다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.222-224
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• 2006

A non-vacuum process for $Cu(In,Ga)Se_2$ (CIGS) thin film solar cells from nanoparticle precursors was described in this work CIGS nanoparticle precursors was prepared by a low temperature colloidal route by reacting the starting materials $(CuI,\;InI_3,\;GaI_3\;and\;Na_2Se)$ in organic solvents, by which fine CIGS nanoparticles of about 20nm in diameter were obtained. The nanoparticle precursors were mixed with organic binder material for the rheology of the mixture to be adjusted for the doctor blade method. After depositing the mixture of CIGS with binder on Mo/glass substrate, the samples were preheated on the hot plate in air to evaporate remaining solvents ud to burn the organic binder material. Subsequently, the resultant (porous) CIGS/Mo/glass simple was selenized in a two-zone Rapid Thermal Process (RTP) furnace in order to get a solar ceil applicable dense CIGS absorber layer. Complete solar cell structure was obtained by depositing. The other layers including CdS buffer layer, ZnO window layer and Al electrodes by conventional methods. The resultant solar cell showed a conversion efficiency of 0.5%.