• Title/Summary/Keyword: resistance increase

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Electrochemical Characteristics of Anode-supported Solid Oxide Fuel Cells (연료극 지지형 고체산화물 연료전지의 전기화학적 특성)

  • Yoon Sung Pil;Han Jonghee;Nam Suk Woo;Lim Tae-Hoon;Hong Seong-Ahn;Hyun Sang-Hoon;Yoo Young-Sung
    • Journal of the Korean Electrochemical Society
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    • v.4 no.2
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    • pp.58-64
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    • 2001
  • YSZ ($8mol\%$ yttria-stabilized zirconia)-modified LSM $(La_{0.85}Sr_{0.15}MnO_3)$ composite cathodes were fabricated by formation of YSZ film on triple phase boundary (TPB) of LSM/YSZ/gas. The YSZ coating film greatly enlarged electrochemical reaction sites from the increase of additional TPB. The composite cathode was formed on thin YSZ electrolyte (about 30 Um thickness) supported on an anode and then I-V characterization and AC impedance analyses were performed at temperature between $700^{\circ}C\;and\;800^{\circ}C$. As results of the impedance analysis on the cell at $800^{\circ}C$ with humidified hydrogen as the fuel and air as the oxidant, R1 around the frequency of 1000 Hz represents the anode Polarization. R2 around the frequency of 100Hz indicates the cathode polarization, and R3 below the frequency of 10 Hz is the resistance of gas phase diffusion through the anode. The cell with the composite cathode produced power density of $0.55\;W/cm^2\;and\;1W/cm^2$ at air and oxygen atmosphere, respectively. The I-V curve could be divided into two parts showing distinctive behavior. At low current density region (part I) the performance decreased steeply and at high current density region (part II) the performance decreased gradually. At the part I the performance decrease was especially resulted from the large cathode polarization, while at the part H the performance decrease related to the electrolyte polarization.

Effects of Unripened Cheese Supplements on Lipid and Antioxidant Status in Hypercholesterolemic SD Rats (고콜레스테롤혈증 흰쥐에서 비숙성치즈의 보충섭취가 지질 및 항산화 체계에 미치는 영향)

  • Seo, Bo-Young;Spengler, Bernhard;Rompp, Andreas;Schober, Yvonne;Yoon, Yoe-Chang;Park, Eun-Ju
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.1
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    • pp.65-72
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    • 2012
  • The aim of this study was to evaluate the effects of unripened cheese supplements on lipid metabolism and antioxidant status in hypercholesterolemic SD rats. Rats were induced to have hypercholesterolemia by feeding them high cholesterol diet (0.5% cholesterol and 0.2% sodium cholate) for 4 weeks and then divided into 2 groups. One group was fed a high cholesterol diet with 5% unripened cheese (URC) daily for 6 weeks, and the other one was fed a high cholesterol diet without 5% unripened cheese (URC) daily for 6 weeks. Significantly-increased plasma total cholesterol (TC), triglycerides (TG), and AST activity because of the high-cholesterol diet were reduced 18.8%, 40.5%, and 33%, respectively, by URC supplementation. Also, URC lowered hepatic total lipids, TCs, and TGs, whereas fecal lipid profiles were not changed by URC. The supplementation of URC resulted in an increase of plasma retinol and ${\alpha}$-tocopherol by 40.5% and 39.2% and leukoytic DNA resistance to oxidative stress by 52.3% compared to hypercholesterolemic control. These results suggest that unripened cheese supplements could exert significant health benefits to those with hypercholesterolemia through ameliorating lipid profiles and antioxidant effects.

Quality characteristics of domestic and imported commercial plain wheat flour (시판 우리밀과 수입밀 중력 밀가루의 품질 특성 비교)

  • Kwak, Han Sub;Kim, Mi Jeong;Kim, Hoon;Kim, Sang Sook
    • Korean Journal of Food Science and Technology
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    • v.49 no.3
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    • pp.304-310
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    • 2017
  • The aim of this study was to compare the physicochemical properties of domestic and imported commercial plain wheat flour and dough. Four types of domestic wheat flour (DW; DW1-4) were compared to four types of imported wheat flour (IW; IW1-4). DWs exhibited lower moisture content, lightness (L), and whiteness, and higher protein content, redness (a), and yellowness (b), than those exhibited by IWs. Solvent retention capacity of DWs and IWs was similar; however, DWs showed higher gluten performance index. Pasting properties, analyzed by rapid visco analyzer (RVA), were similar for DW1, DW2, and IWs; however, DW3 and DW4 showed different RVA patterns. Considering that DW3 and DW4 were organic wheat flour, possible incorporation of damaged kernel might increase amylase activities resulting in decreased peak viscosity. Dough resistance (108.4-159.9 g) and extensibility (11.8-16.7 mm) of IWs were higher than those of DWs (78.0-118.7 g, 8.7-12.5 mm, respectively).

Establishment of Reference Value of Insulin Using the Statistical Analysis (통계적 분석을 통한 Insulin의 정상 참고치 설정)

  • Kim, Whe-Jung;Yoon, Pil-Young;Shin, Young-Goon;Yoo, Seon-Hee;Cho, Shee-Man
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.1
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    • pp.143-146
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    • 2010
  • Purpose: Insulin is involved in carbohydrate metabolism and also it's very important because it increases storage of glycogen, synthesis of fatty acids, absorption of amino acid, synthesis of protein. Insulin is clinically useful when we evaluate fasting patients in hypoglycemia, classify and predict diabetes, assess the activity of ${\beta}$-cell, research insulin resistance. We are going to increase usability of insulin assay by establishing normal reference value according to statistical analysis. Material & Method: We selected 6,648 patients who visited asan health medical center from May to August in 2008. We set exclusion criteria as family of diabetes, diabetes medication, the past history of blood glucose rise, more than 100 mg/dL in normal fasting blood glucose, outside the scope of BMI 18.5~22.9 $kg/m^2$, and more than HbA1c 6.5%. We determine whether the subgroup is portioned as sex and age or not and establish normal reference value by conducting statistical analysis as Bayesian's method and Hoffman's method. Result: Portioning of subgroup as sex and age is not needed. By statistical analysis of Bayesian method, results 1.5-11.0 uIU/mL. By statistical analysis of Hoffman method, results 1.8~12.8 uIU/mL. Conclusion: We established 1.8~12.8 uIU/mL as Insulin normal reference value by Hoffman method. This is a similar value with reporting reference value 1.7~11.8 uIU/mL in kit. This will enhance the usability of insulin assay by establishing normal reference value.

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Effect of 4 Weeks' Walking Exercise with Blood Flow Restriction on Inflammatory index, Isokinetic Muscle Function, and Thigh Circumference in Obese Women (4주간의 혈류를 제한한 걷기운동이 비만여성의 혈중 염증지표와 등속성근기능, 대퇴둘레에 미치는 영향)

  • Park, Man-Soo;Zang, Seok-Am;Lee, Jang-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.10
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    • pp.480-489
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    • 2017
  • Blood flow restriction(BFR) exercise is defined as low intensity and short term exercise using pneumatic pressure belts at the top of limbs, which affects the physiological functions of the body. The purpose of this study was to investigate the effects of walking exercise with BFR on inflammatory index, isokinetic muscle function, and thigh circumference in obese women. Eleven obese women(> BMI $25kg/m^2$ & > body fat 30%) wore pneumatic pressure belts on both femurs and performed walking exercise twice per day, 3 days/wk for 4 weeks (walking 2 min; resting 1 min). Data analysis was carried out using paired t-test. Body weight, BMI, and body fat significantly decreased after exercise(p<.05), and right thigh circumference significantly decreased(p<.05). The concentration of plasma IL-6 significantly increased(p<.05) after exercise. TNF-${\alpha}$ level was not statistically different but tended to slightly increase. CRP slightly decreased, although it did not reach statistical significance after exercise. Muscle strength significantly increased in the $60^{\circ}/sec$ of right/left side extension, left side flexion, and $180^{\circ}/sec$ of left side extension after training(p<.05). These results suggest that 4 weeks of blood flow restriction walking exercise has positive effects on inflammatory index and isokinetic muscle function. Therefore, we consider that blood flow restriction exercise can be used for treatment of obesity, related chronic diseases, and metabolic syndrome. Further, blood flow restriction exercise for a short time has similar effects as a high intensity resistance program.

Inheritance Study of Male Sterile Transformants Containing Pollen-specific Promoter and Diphtheria Toxin A Gene (수술특이프로모터와 디프테리아 독성 유전자에 의한 웅성불임 형질전환체의 후대 유전분석)

  • Park, Young-Doo;Kim, Hyun-Uk;Park, Beom-Seok;Jin, Yong-Moon
    • Horticultural Science & Technology
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    • v.18 no.3
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    • pp.342-347
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    • 2000
  • The objectives of this study were to investigate the genetic and phenotypic features of male sterile transformants by pollen-specific expression of diphtheria toxin gene and to find out inheritance patterns of transgene to the next generation. When backcrossed (BC) progenies were tested for expression of kanamycin resistance ($Km^R$), 9 lines out of 13 lines, except 4 lines ($BC_{1}5-13,\;BC_{1}5-23,\;BC_{1}5-28,\;BC_{1}5-32$), showed the ratio of $Km^R$ to kanamycin sensitive ($Km^S$), from 1:30 to all $Km^S$. As a result, they were much lower than Mendelian segregation of a dominant gene. To determine whether male sterility is a heritable and stable trait, 5 male sterile plants ($BC_{1}5-13,\;BC_{1}5-14,\;BC_{1}5-23,\;BC_{1}5-32,\;BC_{1}5-33$ lines) which had different transgene copy numbers were backcrossed as female parents with pollens from wild type. To confirm the existence of the DTx-A gene in the genome of the progenies, PCR was conducted using specific primers of the DTx-A coding region. A PCR band of 428 bp was obtained from each generation, which is the predicted size of the DTx-A gene fragment. Trangenes were inherited to the next $BC_4T_0$ progenies and showed male sterility, however, based on the copy numbers of DTx-A gene male sterile plants did not show predicted ratio. When male sterile plants were backcrossed with fertile plants, fruit capsule sizes and seed settings were relatively reduced from those of selfing wild type plants. The fruit sizes and seed settings were reduced in proportion to the increase in the copy number of DTx-A gene.

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Regulation of Gb3 Expression on Dendritic Cells (수지상세포에 있어서 베로독소 수용체의 발현조절)

  • Lim, Suk-Hwan;Kim, Gi-Young;Kim, Hyung-Chun;Kim, Young-Hee;Son, Yong-Hae;Oh, Yang-Hyo;Park, Yeong-Min
    • Journal of Life Science
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    • v.17 no.4 s.84
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    • pp.482-492
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    • 2007
  • Infection with Shiga-like toxin (SLT)-producing Escherichia coli causes a spectrum of illnesses with high morbidity and mortality. Host mediators play an important role in the pathogenesis of SLT-I toxicity. We here investigated the effect of SLT-I on tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})$ production, effect of $TNF-{\alpha}$ on glycolipid globotriaosyleramide (Gb3) expression, and relationship between Gb3 level and differential susceptibility of cells to SLT-I. In this study, we observed that detectable levels of $TNF-{\alpha}$ are produced 6 hrs after induction and continued to increase during 48 hrs by SLT-I. It was also found that Vero cells and dendritic cells expressed high levels of Gb3, 83% and 68%, respectively, and that macrophages had a low level of Gb3 (29%) and showed refractory to cytotoxicity against SLT-I. Vero cells and dendritic cells expressing high levels of Gb3 were highly susceptible to SLT-I. furthermore, macrophages showed a resistance to SLT-I cytotoxicity, despite the fact that Gb3 expression was enhanced. These results suggest that the expression of Gb3 is necessary, but not sufficient to confer sensitivity of macrophages to SLT-I and further underpin the important role of SLT-I and its receptor, Gb3, in the pathogenesis of E. coli O157 infection.

Effects of Gastrodia Rhizoma Extracts on Global Coronary Circulation in Rats (천마 Extracts가 백서의 국소적 관상순환기능에 미치는 영향)

  • Kim, Eun-Ji;Ji, Geun-Eog;Kang, Young-Hee
    • Korean Journal of Food Science and Technology
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    • v.26 no.3
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    • pp.213-220
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    • 1994
  • Gastrodia (G) Rhizoma has been used clinically as an oriental herbal medicine with sedative, anticonvulsive, and depressor effects. The present study tested effects of G. Rhizoma extracts on the coronary circulation and myocardial oxygen consumption in perfused rat hearts. Sprague Dawley rats (SD) and spontaneously hypertensive rats (SHR) were employed as experimental animals and nonworking Langendorff heart perfusion technique introduced for heart experiments. G. Rhizoma extracts were prepared from grinding G. Rhizoma into powder, extracting in water and 50% ethanol for 4 or 16 hr and diluting with Krebs-Henseleit bicarbonate perfusion buffer to be 70%. Hearts were perfused with bicarbonate buffer oxygenated with 95% $O_{2}:$ 5% $CO_{2}$ at constant coronary perfusion pressure of $90cmH_{2}O$. The diluted extracts were infused into coronary arteries in a concentration of $1{\sim}5\;{\mu}M$ for $7{\sim}8 min. While in SD water- or ethanol-extracts of G. Rhizoma extracted for 16 hr increased coronary perfusate flow (CPF) and decreased coronary vascular resistance (CVR), ethanol-extracts in SHR produced coronary vasoconstriction associated with enhanced CVR. G. Rhizoma extracts-induced increase in CPF reduced myocardial oxygen extraction, and thus myocardial oxygen consumption ($MVO_{2}$) remained at that observed prior to infusion of extracts. In SD and SHR 16 hr-water-extracts markedly altered coronary venous effluent pH and $Pco_{2}$ and evoked metabolic acidosis, which could be a coronary vasodilator mechanism decreasing CVR. In this study, the extracts decreasing CVR in SD and SHR did not augment the lactate production. Therefore, although the effects of the extracts on cardiac function and coronary circulation depended on solvents and duration for extraction, the 16hr-water-extracts, at least, exhibited coronary vasodilation in SD and SHR. Conversely, ethanol-extracts constricted coronary arteries in SHR. G. Rhizoma extracts-induced vasodilation might be due to the metabolic acidosis rather than due to the increased lactate production. The results indicate that G. Rhizoma extracts obtained from proper extracting procedures can be used as a safe and clinically applicable herbal medicine in the cardiovascular diseases such as coronary artery disease and hypertension for vasodilatory and antihypertensive actions.

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Soil Physical Properties and Organic Matter (토양(土壤)의 물리성(物理性)과 유기물(有機物))

  • Im, Jeong-Nam
    • Korean Journal of Soil Science and Fertilizer
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    • v.11 no.3
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    • pp.145-160
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    • 1979
  • The effects of organic material application on soil physical properties were reviewed in relation to soil productivity. The organic matter contents and soil physical properties of the cultivated land in Korea were summarized and the effects of organic matter were compared in terms of land uses and soil types. Soil physical properties related to crop yield potential, such as soil aggregation, permeability, water holding capacity, erodibility, and compactibility, were used in evaluating the effects of organic materials as a soil physical amendment. The benefical effects of organic matter addition on soil physical conditions include (1) better aeration and increased infiltration in silty and clayey soils, (2) increased water holding capacity and moisture availability in sandy soils, (3) decreased soil erodibility, and (4) increased resistance to compaction. It is, therefore, concluded that continuous application of organic materials could greatly improve the various soil physical properties and favor the growth and yield of crops. A high rate of organic matter addition could contribute to reducing not only the soil erosion on sloping land, but also the possible detrimental effect of farm mechanization. In general, the effects of organic matter on soil physical improvement were estimated to be much higher in upland than in paddy. Organic matter would have a more pronounced effect on low productive lands such as heavy clayey or sandy soils and newly reclaimed soil. The optimum level of soil organic matter content was estimated to be about 3.0 to 3.5% for the best soil physical condition. Since the organic matter contents of the cultivated lands in Korea are much lower than optimum level, it would be desiable to use more organic materials to soil for the increase of soil productivity, continuation of stabilized high productivity and soil erosion control.

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Preventive Effect of Milk Products against Diabetes Mellitus Type 2: A Review (유제품의 제2형 당뇨병 예방 효과: 총설)

  • Kim, Dong-Hyeon;Chon, Jung-Whan;Kim, Hyun-Sook;Kim, Hong-Seok;Song, Kwang-Young;Kim, Young-Ji;Kang, Il-Byung;Lee, Soo-Kyung;Jeong, Dong-Gwan;Kim, Soo-Ki;Seo, Kun-Ho
    • Journal of Dairy Science and Biotechnology
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    • v.33 no.2
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    • pp.129-137
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    • 2015
  • Diabetes mellitus type 2 is a metabolic disorder that is characterized by hyperglycemia (high blood sugar level) in the context of insulin resistance and relative lack of insulin. Recently, much scientific evidence has shown that the risk of diabetes mellitus type 2 could be reduced by dairy intake. A significantly strong relationship has been noted between this disease and dairy intake. In particular, from the different types of fat in dairy foods that were reported to have a beneficial impact, low-fat dairy foods have been found to have the best effect with respect to reducing the risk of diabetes mellitus type 2. Therefore, the role of specific components of dairy foods, such as calcium, vitamin D, dairy fat, and trans-palmitoleic acid, which could be responsible for this effect and for the positive effect of dairy foods in obesity and metabolic syndrome, needs to be identified. There is a strong and relatively consistent body of accumulating evidence indicating that dairy foods may significantly reduce the risk of diabetes mellitus type 2, likely in a dose-response manner. Dairy recommendations should be an essential part of public health guidance, and identifying strategies to increase dairy food consumption to optimal levels is of utmost importance. Hence, this review summarizes various positive effects of dairy foods with respect to reducing the risk of diabetes mellitus type 2, based on available evidence, and discusses the need for further research on preventing or decreasing the risk of diabetes mellitus type 2.

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