• Journal of Life Science
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• v.33 no.5
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• pp.445-454
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• 2023

Hair graying is the result of a malfunction in the signaling pathways that control melanogenesis, and it is activated by UV light, melanocyte-stimulating hormone (MSH), stem cell factor (SCF), Wnt, and endothelin-1 (ET-1). To prevent hair graying, synthetic and natural compounds can be used to stimulate melanogenesis effectively under the control of tyrosinase, tyrosine hydroxylase, tyrosinase-related protein-1 (TRP-1), TRP-2, and microphthalmia-associated transcription factor (MITF). This article describes a crucial strategy to resolve the problem of hair graying, as well as recent advances in the signaling pathway related to melanogenesis and hair graying. In particular, the article reviews potentially effective therapeutic agents that promote melanogenesis, such as antioxidants that modulate catalase, methionine sulfoxide reductase, and sirtuin 1 (SIRT1) activators including resveratrol, fisetin, quercetin, and ginsenoside. It also discusses vitiligo inhibitors, such as corticosteroids, calcineurin inhibitors, and palmitic acid methyl ester, as well as activators of telomerase expression and activity, including estrogen, androgen, progesterone, and dihydrotestosterone. Furthermore, it explores compounds that can inhibit hair graying, such as latanoprost, erlotinib, imatinib, tamoxifen, and levodopa. In conclusion, this article focuses on recent research trends on compounds that promote melanin production related to hair graying.

• Journal of Family Resource Management and Policy Review
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• v.8 no.1
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• pp.79-100
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• 2004

This study attempted to examine the employment instability on consumer's use of credit as a financing medium. The purpose of this study was 1) to examine the effect of employment related factors on consumers' use of credit; 2) to compare the results between the two different economic situations. A conceptual framework was developed based on the permanent income hypothesis, family stress theory, and the previous empirical studies. Using data on working households ih the 1992 and 1998 Survey of Consumer Finances (SCF), double-hurdle analyses were conducted. The results suggested that employment related factors that measured employment stability were significantly related to the likelihood of having an outstanding balance on their credit account but were not the influential factors in determining the amount of the outstanding balance. Among other factors, resources factor played the most significant role in determining both the likelihood of having an outstanding balance and the amount of the balance. Although the 1992 and 1998 data represent economic downturn and economic prosperous period, the effects of the factors including employment instability factors were similar between the two periods. This imply that employment instability has increased even in the economic prosperous period. From the findings, several implications for policy makers, credit industry, and financial educators were suggested.

• Journal of Nutrition and Health
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• v.17 no.1
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• pp.68-77
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• 1984

The present study was designed to observe the effects of soyprotein and casein with or without cholesterol on serum and liver lipids in male rats. The 6 experimental groups were as fellows ; SF ; soyprotein, cholesterol-free diet. SC ; soyprotein, 0.5% cholesterol added diet. CF ; casein, cholesterol-free diet CC ; casein,0.5% cholesterol added diet. SCF ; protein mixture of soyprotein and casein(1 : 1), cholesterol-free diet SCC ; mixed protein, 0.5% cholesterol added diet. The hypocholesterolemic and hypotriglyceridemic effects of soyprotein were observed at 3 weeks, but these effects disappeared at 6 weeks. The hypocholesterolemic effect of soyprotein was more obvious when the 0.5% cholesterol was supplemented in the diets. The serum free cholesterol level was not affected by the dietary protein source or the dietary cholesterol, therefore, the difference in serum total cholesterol among groups seems due to the difference in cholesterol esters. There was a tendency of a higher percentage of HDL in soyprotein groups compared to casein groups at 1 week, however, this tendency disappeared with time. The liver cholesterol and triglyceride contents were not differ among cholesterol-free diet groups, however, with addition of cholesterol, those of soyprotein groups were significantly lower than casein groups. The higher serum arginine/lysine ratio of soyprotein groups may offer the part of explanation of its hypocholesterolemic effect.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1993.05a
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• pp.85-87
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• 1993

We have investigated three polyene systems, $X-(-HC=CH-)_n-Y$, where X/Y=H/H, $F/CH_3$, and $NH_2/NO_2$. We estimated asymptotic values (for $n=\infty$ of the electronic properties with $logA=a_o+a_1/(n+1)+a_2/(n+1)^2+a_3/(n+1)^3$, so that the cases n=0 can be included in that equation. Here, A can be $\mu$, $\beta$, $\alpha/(n+1)$ or $\gamma/(n+1)$. For these asymptotic values. the SCF results are more reliable due to the higher level of theory, while the PM3 results can give better trend with more data for polyene systems with longer chain length.

• Composites Research
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• v.29 no.6
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• pp.388-394
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• 2016

Fiber reinforced plastic (FRP) composites have drawn increasing attentions worldwide for decades due to its outstanding properties. Stress concentration factor (SCF) as an essential parameter in materials science are critically considered in structure design and application, strength assessment and failure prediction. However, investigation of stress concentration in FRP composites has been rarely reported so far. In this study, three resource-conserving analyses (Isotropic analysis, Orthotropic analysis and Finite element analysis) were introduced to plot the $K_T^A-d/W$ curve for E-glass/epoxy composite plate with the geometrical defect of circular hole placed centrally. The plates were loaded to uniaxial direction for simplification. Finite element analysis (FEA) was carried out via ACP (ANSYS composite prepost module). Based on the least squares method, a simple expression of fitting equation could be given based on the simulated results of a set of discrete points. Finally, all three achievable solutions were presented graphically for explicit comparison. In addition, the investigation into customized efficient SCFs has also been carried out for further reference.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.5
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• pp.372-379
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• 2015

The blade root fillets which have strong influences on the performance of propellers in the both structural and hydrodynamic points of view, are mechanical parts for smooth connection surface with a blade and a hub. A few related researches (Sabol, 1983; Kennedy, 1997) have noted that 3T-T/3 double radius section design would be suitable for reducing Stress Concentration Factor(SCF) and increasing Cavitation Inception Speed(CIS). In this paper, it is confirmed that this compound cross-section design has come close to the optimum solution in the shape optimization standpoint so that it could protect the propeller blade under the frequent and various loading cases. On that basis, we suggest the definite and simple fillet design methodology that has the cross-section with nT-T/n compound radius and elliptic shape which could sustain the given derivatives information as well as the offsets at the boundary and all inner region of the fillet surface. In addition, the result of design is presented in form of IGES file format in order to connect with NC machine seamlessly.

• Biomolecules & Therapeutics
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• v.15 no.4
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• pp.230-234
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• 2007

In anti-cancer therapies, radiotherapy and chemotherapy show a superior inhibition effect on cancer cell growth, but those are very toxic to normal tissues and organs. Particularly, drugs for neutropenia, one of chemotherapy agents, which suppress the function of bone marrow, are needed to be controlled in terms of their dosage and therapy period because of their side effect. Phellinus linteus polysaccharide (PL) has been reported to increase the number of splenocytes and bone marrow cells. PL has been shown to decrease the side effects of cyclophosphamide (CYC) treatment to the cancer patients. PL showed no effects in semisolid clonogenic assay, suggesting that PL doesn't contain substantial compounds to substitute for colony stimulating factors (CSFs). On the other hand, PL increased the expression of SCF, IL-3, GM-CSF, TPO genes. These results indicate that PL may promote the growth and proliferation of splenocytes and bone marrow cells through indirect or CSFs-dependent pathway, which may lead to a hematopoiesis.

• Journal of Mechanical Science and Technology
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• v.18 no.5
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• pp.808-813
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• 2004

The stress analysis on orthotropic composite cylindrical shells with one circular or one elliptical cutout subjected to an axial force is carried out by using an analytical and experimental method. The composite cylindrical shell governing equation of the Donnell's type is applied to this study and all results are presented by the stress concentration factor. The stress concentration factor is defined as the ratio of the stress on the region around a cutout to the nominal stress of the shell. The stress concentration factor is classified into the circumferential stress concentration factors and the radial stress concentration factors due to the cylindrical coordinate of which the origin is the center of a cutout. The considered loading condition is only axial tension loading condition. In this study, thus, the maximum stress is induced on perpendicular region against axial direction, on the coordinate. Various cutout sizes are expressed using the radius ratio, (equation omitted), which is the radius of a cutout over one of the cylindrical shell. Experimental results are obtained using strain gages, which are attached around a cutout of the cylindrical shell. As the result from this study, the stress concentration around a cutout can be predicted by using the analytical method for an orthotropic composite cylindrical shell having a circular or an elliptical cutout.

• Korean Management Science Review
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• v.32 no.3
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• pp.13-28
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• 2015

Using the most recent dataset of Korea and U.S. household finance, this study analyzed demand and adequacy of private pensions for pre-retirees. For this purpose, 2013 Korean Retirement and Income Study (KReIS) of national pension research institute in Korea and 2013 SCF (Survey of Consumer Finances) of FRB in U.S. were used. For comprehensive comparisons of the two countries, this study classified the private pension into sub-categories such as personal pension, corporate pension, and retirement benefits, and used three different criteria including ownership, accumulated present value of each pension, and income replacement ratio of each pension. After controlling for other factors, educational level of householder and household income were critical determinants of size and adequacy of private pension in both countries. Different from Korean households, householders' gender, marital status, and health status had an important effect on the private pension size and adequacy in the U.S. In addition, home ownership significantly increased only private pension adequacy in Korea, and also increased ownership rate, size, and adequacy of private pension in the U.S. Results of this study provide useful implications for future pension system and policy in Korea.

• Journal of the Korean Chemical Society
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• v.27 no.6
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• pp.399-404
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• 1983

Raman spectra for the carbonyl stretching mode of the amides, and amide-solvent systems have been recorded to investigate the effect of alkyl substitutions at the carbonyl carbon and at the nitrogen on the amide hydrogen-bonding. The data have shown that the interaction affinities are in the order of amide-amide > amide-water > amide-alcohol in formamide system, and amide-water > amide-amide > amide-alcohol in acetamide and propionamide systems. The strength of the proton acceptor of the carbonyl oxygen is increased by the presence of alkyl group to the carbonyl carbon and the proton donorcity of the amide is decreased by the alkyl substitution at the nitrogen. The above results are in good agreement with the ab initio SCF MO calculation.