• Title/Summary/Keyword: Activity stability

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Degradation of a nano-thick Au/Pt bilayered catalytic layer with an electrolyte in dye sensitized solar cells (염료감응태양전지의 Au/Pt 이중 촉매층의 전해질과의 반응에 따른 열화)

  • Noh, Yunyoung;Song, Ohsung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.6
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    • pp.4013-4018
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    • 2014
  • A 0.45 $cm^2$ DSSC device with a glass/FTO/blocking layer/$TiO_2$/N719(dye)/electrolyte/50 nm-Pt/50 nm-Au/FTO/glass was prepared to examine the stability of the Au/Pt bilayered counter electrode (CE) with electrolyte and the energy conversion efficiency (ECE) of dye-sensitized solar cells (DSSCs). For comparison, a 100 nm-thick Pt only CE DSSC was also prepared using the same method. The photovoltaic properties, such as the short circuit current density ($J_{sc}$), open circuit voltage ($V_{oc}$), fill factor (FF), and ECE, were checked using a solar simulator and potentiostat with time after assembling the DSSC. The microstructure of the Au/Pt bilayer was examined by optical microscopy after 0~25 minutes. The ECE of the Pt only CE-employed DSSC was 4.60 %, which did not show time dependence. On the other hand, for the Au/Pt CE DSSC, the ECEs after 0, 5 and 15 minutes were 5.28 %, 3.64 % and 2.09 %, respectively. The corrosion areas of the Au/Pt CE determined by optical microscopy after 0, 5, and 25 minutes were 0, 21.92 and 34.06 %. These results confirmed that the ECE and catalytic activity of Au/Pt CE decreased drastically with time. Therefore, a Au/Pt CE-employed DSSC may be superior to the Pt only CE-employed one immediately after integration of the device, but it would degrade drastically with time.

Self-Efficacy and Self-Control Effects on Purchasing Intention of Annuity Savings Plans: Considering Financial Literacy (금융 유통산업에서의 자기효능감과 자기통제가 연금저축 가입의도와 가입행동에 미치는 영향: 금융이해력에 따른 차이분석)

  • Lee, Yun-Bok;Lee, Phil-Soo;Hwang, Jae-Kwang
    • Journal of Distribution Science
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    • v.13 no.11
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    • pp.69-77
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    • 2015
  • Purpose - Economic status at an early stage of life after one's retirement is often determined by the long-term sacrifice of one's earlier consumption tendencies. In general, the first and foremost way to secure income after retirement is through annuity savings. People sign up for personal annuity savings in order to guarantee a stable economic life upon retirement, and such actions may be heavily influenced by self-efficacy. Confidence in current economic activity is a source of rational decision-making. Inability to achieve self-control can lead to reckless spending and the eventual hindering of proper investment for the future. This paper examines how self-efficacy and self-control affect the intention and action of enrolling in an annuity savings plan in relation to one's level of financial literacy. Research design, data, and methodology - To analyze the proposed model, this study investigates financial consumers over the age of 20. The data were collected from 511 respondents and analyzed with SPSS 21.0 and AMOS 21.0. First, for the one-dimensional test and to measure the convergent validity of each structure, we use the scale purification process. The results of the test and the confirmatory factor analysis ensure the focus of the validity of the single dimension for each structure. In addition, the validity of the measurement was guaranteed from the results of correlation analysis. Results - First, self-efficacy and self-control have positive effects on the purchasing intention of the personal annuity savings plan. Second, purchasing intention positively affects purchasing behavior. Lastly, self-control has a positive effect on purchasing intention among the low financial literacy group, whereas self-efficacy does not have this effect in the high financial literacy one. Conclusions - The time of product benefit is different with age. The younger group would be granted the savings after several decades once they enroll, whereas the older group would wait for a relatively shorter period of time. Therefore, further research should be conducted in order to verify such a difference. However, this study has value through its confirmation that the roles of self-efficacy and self-control play a part in leading to the enrollment in annuity savings plans and by verifying different effects based on levels of financial literacy. Such results suggest a number of implications in a real life setting. First, banks need to put greater emphasis on the stability of annuity savings in general. Second, customers with relatively low levels of financial literacy are able to control their finances through annuity savings, but find self-efficacy difficult due to a lack of financial understanding. Therefore, such customers should be approached from an invest-effectiveness comparison method. Third, customers with high financial literacy tend to put more value in rational economic decision-making and behavior than in self-efficacy. Therefore, such customers should be approached by promoting the reliability of annuity savings and the excellence of the specific bank's annuity savings plan in comparison to those of other financial institutions.

Encapsulation of Pine Agaric ( Tricholoma matsutake) Flavor with Alginates (알긴산을 이용한 송이 향의 캡슐화)

  • You Byeong Jin;Lim Yeong seon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.35 no.3
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    • pp.231-236
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    • 2002
  • Encapsulating 1-octen-3-ol with alginates solution, the effects of physical properties (viscosity, emulsion activity, emulsion stability) of alginates solutin on the retention of 1-octen-3-ol in capsules were investigated. Only alginates solutions haying less than 350 cP in viscosity were capable to be adopted to spray dry. Adding citric acid to alginates solution in order to reduce its viscosity, the concentration of citric acid became higher, the viscosity of alginates solution were lower. Adding $0.1\% of citric acid could reduce viscosity of alginates solution to 150 cP. The viscosity of alginates solution after emulsifying showed higher value than that of solution before emulsifying, but its viscosity were within the possible ranges for spray drying. The lower viscosity of alginates solution were, EAI became higher but ESI and amount of remaining 1-octen-3-ol in capsules were lower, In reducing the viscosity of alginates solutions, heating time after adding citric acid were longer, the their viscosity became lower. Differences of viscosity of alginates solution after and before emulsifying were little, In encapsulating raw pine agaric with alginates solution, the adding amount of soybean oil increased, the amounts of remaining 1-octen-3-ol in capsules increased. After freeze drying the amount of remaining 1-octen-3-ol in alginates capsules prepared with raw pine agaric was higher than that after cold air flow drying.

Preparation of Silica Coated Zinc Oxide and UV Protection Effect (이산화규소가 코팅된 산화아연의 제조와 자외선 차단 특성)

  • Kim, Won Jong;Kang, Kuk Hyoun;Lee, Gi Yong;Kim, Tae Won;Choi, Jong Wan;Lee, Dong Kyu
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.40 no.2
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    • pp.121-131
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    • 2014
  • Due to the high UV light scattering effect of Zinc oxide (ZnO), it is frequently used in sunscreen skincare products. Recently ZnO coated with silica has been used in cosmetics to improve UV protection, texture, decreased photocatalytic activity, dispersibility and stability of the skin care product. In this study, we developed a ZnO composite powder coated with silica for the future application to skincare products to block UV rays that could cause photoaging. To improve consumer's satisfaction rating, we used ZnO microparticles which are widely used in the cosmetics industry. The silica was coated using hydrothermal method with sodium silicate and acid hydrolysis. UV protection of the composite powder was analyzed by UV-Vis and in-vitro test and the advantages for practical use of this powder as a skincare product were determined.

Inhibitory effect of by Ojeok-san lipid accumulation in high fat diet-induced obesity mice and 3T3-L1 adipocytes (오적산 (五積散)의 고지방식이 마우스 지방축적억제 및 3T3-L1지방세포에서의 비만 조절 기전에 관한 연구)

  • Choi, Hye-Min;Moon, Sung-Ok;Lee, Hee-Hyun;이, 화동
    • The Korea Journal of Herbology
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    • v.30 no.4
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    • pp.121-128
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    • 2015
  • Objectives : Ojeok-san (OJS), an oriental herbal formula, has been used in Asian countries including Korea, China and Japan to treat the common cold and illnesses including fatigue and gastrointestinal disorders. The purpose of this study was to examine the anti-obesity effect and molecular mechanism of OJS, on adipogenesis in 3T3-L1 cells. Also, the effects of OJS in obese mice fed a high-fat diet on adiposity were examined.Methods : Preferentially, we analyzed the component of OJS and measured the stability of its component in OJS according to study periods using high performance liquid chromatography (HPLC). In vitro, 3T3-L1 cells were treated with OJS (50 to 200 μg/mL) during differentiation for 8 days. The accumulation of lipid droplets was determined by Oil Red O staining. The expressions of genes related to adipogenesis were measured by RT-PCR and Western blot analyses. For anti-obesty effect in vivo, we experimented for 8 weeks with four group (normal diet (CON), high-fat diet (HF), high-fat diet with OJS (HF+OJS) and high-fat diet with Bang-pung-tong-sung-san (HF+BTS) in comparison group HF+OJS).Results : OJS showed inhibitory activity on adipocyte differentiation at 3T3-L1 preadipocytes without affect cell toxicity as assessed by measuring fat accumulation and adipogenesis. In addition, OJS significantly reduced the expression levels of several adipocyte marker genes including proliferator activated receptor-γ(PPAR-γ) and CCAAT/enhancer-binding protein-α(C/EBP-α). Also OJS-administered mice showed significant inhibitory of body weights and abdominal adipose tissue weights.Conclusions : This study showed that traditional medicine OJS has an anti-obesity effect in vitro and in vivo. Thus, OJS could be developed as a supplement for reduction of body weight gain induced by an obesity.

Effects of Paf1 complex components on H3K4 methylation in budding yeast (출아효모에서 Paf1 복합체의 구성원들이 H3의 네번째 라이신의 메틸화에 미치는 영향)

  • Oh, Jun-Soo;Lee, Jung-Shin
    • Korean Journal of Microbiology
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    • v.52 no.4
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    • pp.487-494
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    • 2016
  • In Saccharomyces cerevisiae, Paf1 complex consists of five proteins, and they are structurally and functionally well conserved in yeast, fruit fly, plants, and human. With binding to RNA polymerase II from transcription start site to termination site, Paf1 complex functions as a platform for recruiting many types of transcription factors to RNA polymerase II. Paf1 complex contributes to H2B ubiquitination and indirectly influences on H3K4 di- and tri-methylation by histone crosstalk. But the individual effects of five components in Paf1 complex on these two histone modifications including H2B ubiquitination and H3K4 methylation largely remained to be identified. In this study, we constructed the single-gene knockout mutants of each Paf1 complex component and observed H3K4 mono-, di-, and trimethylation as well as H2B ubiquitination in these mutants. Interestingly, in each ${\Delta}paf1$, ${\Delta}rtf1$, and ${\Delta}ctr9$ strain, we observed the dramatic defect in H3K4 monomethylation, which is independent of H2B ubiquitination, as well as H3K4 di- and trimethylation. However, the protein level of Set1, which is methyltransferase for H3K4, was not changed in these mutants. This suggests that Paf1 complex may directly influence on H3K4 methylation by directly regulating the activity of Set1 or the stability of Set1 complex in an H2B ubiquitination independent manner.

Optimization of $CO_2$ Direct Absorption Method for the Determination of Carbon-14 in Environmental Samples (환경시료중의 방사성탄소 측정을 위한 $CO_2$ 직접흡수법의 최적화 연구)

  • Cho, Soo-Young;Woo, Hyung-Joo;Chun, Sang-Ki
    • Journal of Radiation Protection and Research
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    • v.23 no.4
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    • pp.237-242
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    • 1998
  • The goal of this work was to optimize the liquid scintillation counting techniques for the determination of C-14 in environmental samples such as biological and air samples. Carbon-14 activities in most environmental samples were measured with direct $CO_2$ absorption method. The highest figure of merit was found through the variation of Carbosorb $E^{TM}$ and Permatluor $V^{TM}$ ratio, in the measurement windows. The best condition was 1:1 volume ratio. Average 2.35 g of $CO_2$ was reproducibly absorbed in the 20 ml mixture within 40 min. The counting efficiency determined by repeated analysis of NIST oxalic acid standard and the background count rate were measured to be $58.8{\pm}1.4%$ and $1.88{\pm}0.06\;cpm$, respectively in case of saturated solution. The correction curves of counting efficiency for partially saturated solutions and for saturated solutions with quenching were prepared, respectively. The overall uncertainty of the sample specific activity for near background levels was estimated to be about 7 % for 4 hours counting at 95 % confidence level. The long-term stability of samples has been checked for all the counting techniques over a two week periods, and no apparent change in counting efficiency and background level was found at that time.

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Probiotic Effects of Lactobacillus plantarum and Leuconostoc mesenteroides Isolated from Kimchi (김치에서 분리한 Lactobacillus plantarum과 Leuconostoc mesenteroides의 프로바이오틱 효과)

  • Lee, Kyung-Hee;Bong, Yeon-Ju;Lee, Hyun Ah;Kim, Hee-Young;Park, Kun-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.1
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    • pp.12-19
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    • 2016
  • The probiotic effects of kimchi lactic acid bacteria (LAB), Lactobacillus plantarum (Lab. plantarum) and Leuconostoc mesenteroides (Leu. mesenteroides), were studied. Lab. plantarum KCCM 11352P (LPpnu) and Leu. mesenteroides KCCM 11353P (LMpnu) were isolated from kimchi and were the predominant LAB. We compared their probiotic effects with Lactobacillus rhamnosus GG (LRgg), a well-known probiotic LAB. LPpnu showed better probiotic activities than LRgg. LMpnu also exhibited almost equal activities as LRgg. These two kimchi LAB strains exhibited resistance to gastric and bile acid, adhesion to intestines, and thermal stability. In particular, LPpnu showed excellent probiotic properties. In addition, LPpnu showed greater antioxidant activity by scavenging DPPH radicals or hydroxyl radicals than LMpnu or LRgg. LPpnu also inhibited growth of HT-29 human colon cancer cells by inducing apoptosis, increasing Bax and suppressing Bcl-2 expression compared to LMpnu or LRgg. Taken together, LPpnu and LMpnu could be used as probiotics, and LPpnu exhibited the most beneficial probiotic activities with anti-oxidant and anti-cancer properties.

Functionalities of Squid Liver Hydrolysates (오징어 간 가수분해물의 기능성)

  • Lee, Su-Seon;Park, Si-Hyang;Park, Joo-Dong;Konno, Kunihiko;Choi, Yeung Joon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.12
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    • pp.1677-1685
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    • 2012
  • The autolysate and hydrolysate of a common squid liver, Todarodes pacificus, were prepared. Autolysis (liver ratio, pH, temperature) and Protamex-treated hydrolysis (pH, temperature, ratio of protease to liver) conditions were optimized by response surface methodology using central composite design for under 1 hr of hydrolysis time. The desirability profile indicated that maximum DH could be achieved at a squid liver of 93.5%, pH 6.4, and $47^{\circ}C$ in autolysis, while that of Protamex-treated hydrolysis did at a Protamex-to-squid liver level of 0.33%, pH 6.0, and $55^{\circ}C$. Three amino acids, proline, cysteine, and methionine, were not detected in the total amino acid composition of the Protamex-treated hydrolysate, while they were detected in the free amino acid composition. Cadmium was $8.32{\pm}0.03$ mg/100 g-powder for raw, $3.56{\pm}0.02$ mg/100 g-powder for the autolysate, and $13.26{\pm}0.04$ mg/100 g powder for the Protamex-treated hydrolysate. The major molecular weight ranged from 1.0 to 1.5 kDa for the autolysate and from 210 to 470 Da for the Protamex-treated hydrolysate. Food functionalities of the autolysate, such as surface hydrolphobicity, emulsion activity index, emulsion stability, water, and fat adsorption, were similar to the Protamex-treated hydrolysate. Both the autolysate and Protamex-hydrolysate showed high inhibitory activities on the angiotensin-I converting enzyme. Cell toxicity against the HepG2 cell line was not detected in the autolysate or the Protamex-treated hydrolysate by 200 ${\mu}g/mL$.

Effect of Different Supporting Surfaces on Trunk Muscle Activities during Core Stabilization Exercises (지지면 차이에 따른 안정화 운동 시 몸통의 근활성도에 미치는 효과)

  • Chang, Chung-Hoon;Ryaung, Seung-Hun;Kang, Kyung-Du;Kim, Jung-Geun;Park, Hae-Young;Min, Ju-Ri;Park, Hyeog-Su;Park, Hyeong-Eun;Kim, Hyun-Jung;Park, So-Yeon;Kim, Ha-Jung;Han, Sang-Wan
    • Journal of the Korean Academy of Clinical Electrophysiology
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    • v.9 no.2
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    • pp.31-38
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    • 2011
  • Purpose : The purpose of this study was to compare the effects of different supporting surfaces on trunk muscle activities during core stabilization exercises. Methods : A total of 20 healthy college students participated in this study for 6 weeks. In this study, we divided participants into a stable surface exercise group and an unstable surface exercise group. Each group performed core stabilization exercises of Curl-ups, Bridges, and Quadrupedal position. Core stabilization exercises were performed 3 times a week for 30 minutes during 6 weeks. The stable surface exercise group used a yoga mat while the unstable surface exercise group used AERO step. This study was designed using pre-test and post-test measurements. We used Surface Electromyograpy (sEMG) to measure for the rectus abdominis, external abdominal oblique, and multifidus muscle of trunk muscle activities. Data was processed using a paired sample t-test on SPSS 18.0. Results : For the stable surface exercise group there was a meaningful improvement in left rectus abdominis, left external abdominal oblique, and right multifidus (p<0.05). For the unstable surface exercise group, a meaningful improvement was seen in the left external abdominal oblique and right multifidus. Conclusion : From the experiment, we concluded that differences in surface can make various degrees of improvement in muscles activities, which suggests patients can choose a better option under their own conditions when planning to have a core stability exercise.