• Journal of Life Science
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• v.29 no.6
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• pp.653-661
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• 2019

The first small interfering RNA (siRNA) therapeutics have recently been approved by the Food and Drug Administration in the U.S., and the demand for a new RNA therapeutics bioanalysis method-which is essential for pharmacokinetics, including the absorption, distribution, metabolism, and excretion of siRNA therapeutics-is rapidly increasing. The stem-loop real-time qPCR (RT-qPCR) assay is a useful molecular technique for the identification and quantification of small RNA (e.g., micro RNA and siRNA) and can be applied for the bioanalysis of siRNA therapeutics. When the anti-HPV E6/E7 siRNA therapeutic was used in preclinical trials, the established stem-loop RT-qPCR assay was validated. The limit of detection was sensitive up to 10 fM and the lower limit of quantification up to 100 fM. In fact, the reliability of the established test method was further validated in three intra assays. Here, the correlation coefficient of $R^2$>0.99, the slope of -3.10 ~ -3.40, and the recovery rate within ${\pm}20%$ of the siRNA standard curve confirm its excellent robustness. Finally, the circulation profiles of siRNAs were demonstrated in rat serum, and the pharmacokinetic properties of the anti-HPV E6/E7 siRNA therapeutic were characterized using a stem-loop RT-qPCR assay. Therefore, the stemloop RT-qPCR assay enables accurate, precise, and sensitive siRNA duplex quantification and is suitable for the quantification of small RNA therapeutics using small volumes of biological samples.

• Journal of Life Science
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• v.33 no.2
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• pp.169-175
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• 2023

As a protective defensive mechanism against ultraviolet (UV) light exposure in skin tissue, melanocytes produce the pigment melanin. Tyrosinase plays a key role in melanin production in melanocytes. However, the overproduction of melanin can lead to lesions, such as freckles and dark spots. Thus, it is clinically important to find a modulating molecule to control melanogenesis by regulating tyrosinase expression and/or activity. It is known that catechin, a plant flavonoid, can reduce melano- genesis through the downregulation of tyrosinase expression. Here, we tested whether catechin derivatives isolated from the stem bark of Ulmus parvifolia have an effect on melanin production by regulating tyrosinase in mouse melanoma cells and in vitro mushroom tyrosinase. The catechin derivatives used in this study included C5A, C7A, C7G, and C7X. Treatments using these catechin derivatives reduced melanin production in mouse melanoma B16F10 cells in which melanogenesis was stimulated by α-MSH. Notably, the anti-melanogenic effects of catechin derivatives were similar to those of kojic acid, a well-known anti-melanogenic molecule. Both C5A and C7A directly inhibited the activity of tyrosinase isolated from mushrooms in vitro. Furthermore, our in silico computational simulation showed that these two compounds were expected to bind to the active site of tyrosinase, which is similar to kojic acid. In addition, all four catechin derivatives reduced tyrosinase protein expression. In summary, our results showed that catechin derivatives can reduce melanogenesis by regulating tyrosinase activity or expression. Thus, this study suggests that catechin derivatives isolated from U. parvifolia can be novel modulators of melanin production.

• Solar Energy
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• v.10 no.3
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• pp.13-18
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• 1990

When nonuniform thermal boundary conditions are imposed on the surface of a circular cylinder in crossflow, the heat transfer characteristics can be quite different compared to what is found for isothermal or constant heat flux boundary conditions. In the present analysis, two kinds of nonuniform boundary conditions along the circumference of the cylinder are considered in a uniform stream of air: step changes and linear profiles. Step changes in temperature can arise on the surface of an external, cylindrical, solar central receiver. As the working fluid(water) flows through the vertical tubes that ring the circumference of Solar One(a solar central receiver in Barstow, California), the solar flux on the receiver heats the water from a liquid to a superheated state. In this process, portions of the receiver panels, and thus portions of the circumference of the cylinder, function as a preheater, boiler, or superheater. Hence the surface temperature can vary significantly around the cylinder. Common engineering practice has been to use an average wall temperature with an isothermal cylinder heat transfer coefficient when estimating the convective loss in these kinds of situations.

• Lingua Humanitatis
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• v.2 no.2
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• pp.85-107
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• 2002

The word play on h(e)art-hunting has become a virtual commonplace in criticism of Chaucer′s Book of the Duchess. Less widely discussed is the third meaning of ME herte, "hurt." The "hart"/ "heart" pun is, however, only implicit in the poem, while the rhyme of "heart" and "hurt" in lines 883-84 makes clear the close association of the terms for Chaucer. Earlier commentators insisted that this was in fact an instance of rime riche or "identical rhyme," but if it is so it is striking that it is the unique instance of the rhyme in Chaucer, whose works are full of occasions for hurt hearts. The essay argues that this is, instead, an instance of near-rhyme and that the confusion in scribal spellings of ME hurten(with ′u,′ ′0,′ ′i,′ ′y,′ and ′e′ ) suggests uncertainties about its root vowel that modem linguistic study has not clarified completely. If the rhyme of herte ("hurt") with herte ("heart") is, however, established by these lines in BD, then it is probably reasonable to ask about all the occasions where characters in the poem are hurt by emotional or physical distress. In the cases of A1cyone and the Man in Blak, the hurt is revealed plainly as the death of a loved one, and Alcyone′s death and the Man in Blak′s return "homwarde" offer contrasting responses to the realization and acknowledgement of their loss. In the case of the Narrator, however, the exact nature of his "hurt" is nowhere made clear and the questions this Jack of clarity raises for the reader remain unanswered when the poem declares its "hert-huntyng" done. Further examination of the Narrator′s character and his role in the poem may reveal him to be a physician himself in need of healing, and this reading of his character may identify him as an ancestor as much of Chaucer′s Pardoner as of the Pilgrim Narrator of Canterbury Tales.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1034-1038
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• 1995

The purpose of this study is to research and develop $TiS_2$ composite cathode for lithium polymer battery(LPB). $TiS_2$ electrode represent a class of insertion positive electrode used in Li secondary batteries. In this study, we investigated preparation of $TiS_2$ composite cathode and AC impedance response of $TiS_2$ composite/SPE/Li cells as a function of state of charge(SOC) and cycling. The resistance of B type cell using $TiS_2PEO_8LiClO_4PC_5EC_5$ composite cathode was lower than that of A type cell using $TiS_2PEO$ composite cathode. The cell resistance of B type cell is high for the first few percent discharge, decreases for midium discharge and then increases again toward the end of discharge. We believe the magnitude of the cell resistance is dominated by passivation layer impedance and small cathode resistance. AC impedance results indicate that the cell internal resistance increase with cycling, and this is attributed to change of passivation layer impedance with cycling. The passivation layer resistance($R_f$) of B type cell decreases for the 2nd cycling and then increases again with cycling. Redox coulombic efficiency of B type cell was about 141% at 1st cycle and 100% at 12th cycle. Also, $TiS_2$ specific capacity was 115 mAh/g at 12 cycle.

• Journal of Adhesion and Interface
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• v.10 no.2
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• pp.84-89
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• 2009

The objective of this research was to investigate the curing behavior and adhesion performance of urea-melamine-formaldehyde (UMF) resin for the four types of UMF-1, UMF-2, UMF-3, and UMF-4 which synthesized by the staged addition of melamine. Also, various network structures of these resin types were discussed based on their different curing behavior and adhesion performance. The curing behavior was evaluated by DMTA and thermal stability was checked by TGA. Adhesion performance was evaluated by dry and wet shear strengths and the pH value of each cured resin was checked to see its effect on the adhesion performance. The results indicated that the UMF-1 resin type by the addition of melamine initially with the urea and formaldehyde at the same F/(U+M) rate showed the lowest thermal stability, rigidity (${\Delta}E^{\prime}$), temperature of tan ${\delta}$ maximum ($T_{tan}\;_{\delta}$), and wet shear strength, and pH value of cured resin. In wet shear strength, however, the UMF-4 resin type appears to be slightly higher than UMF-1 resin type.

• The Journal of Korean Society for School & Community Health Education
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• v.12 no.3
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• pp.29-41
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• 2011

배경 및 목적 : 미국과한국양국의대학생의음주문제는심각한사회문제이며, 대학생의음주문제를예방하기 위한 다양한 노력들이 시도되고 있다. 본 연구는 미국과 한국대학생들의 음주와 폭음에 대한 인식 및 태도에 차이가 있는지를 비교 분석하기 위해 설계되었다. 방법 : 데이터는 2001년 미국의 하버드 보건대학원의 College Alcohol Study (CAS) 팀에서 미국의 120개 4년제 대학에서 10,904명에게서 조사한 원자료와 한국에서는2003년 삼육대학교 보건복지대학원의 Korean College Alcohol Study (KCAS) 팀에서 전국의 60개 4년제 대학의 2,385명의 원자료를 함께 통합하여 사용하였다. 이 자료의 특징은CAS에서 개발한설문지를 한국과 미 국양측에서 공동으로 사용하여 양 국가를 대표한 4년제 대학생의 표본을 대상으로 음주와 관련된 조사를 수행한 점이다. 결과 : 한국남학생들이 폭음할 기회가7.74배더많고 여학생의 경우는3.36배 더많다. 지난 한달동안 3회 이상 술 취한 경험율에서 한국 남학생들의 경험율이 34.3%로 미국의 20.4%보다 많고, 여학생의 경우도 24.6%로 미국 여학생의 11.1%보다 현저히 더 많다. 한국 대학생들의 폭음자 비율이 미국 대학생들의 폭음자 비율보다 많은 것과같이, 한국 대학생들이 미국의 대학생들 보다 폭음이 안전한 것으로 인식하고 있으며, 음주에있어서도더욱허용적인태도를가지고있다. 한국남학생의78.4%와 여학생의67.3%가 폭음 이상의 량을 안전하다고 인식하고 있다(미국은 남학생은 50.3%, 여학생은 34.1%). 폭음에 해당하는 음주량(남자는5잔 이상, 여자는4잔 이상)을안전하다고인식하는정도에서한국의대학생들이미국의대학생들에 비해서 남학생은 4.06배, 여학생이 3,96배 더 높다. 결론 : 한국 학생들 중에서도 음주의 량이 더 많은 학생들이 다른 학생들보다 음주와 술 취함과 폭음에 관하여 더욱 허용적이고, 안전한 음주에 대해 더욱 둔감한 태도와 신념을 보이고 있다.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.110.1-110.1
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• 2010

A bench scale slurry bubble column reactor (SBCR) with active-Fe based catalyst was developed for the Fischer-Tropsch synthesis (FTS) reaction. Considering the highly exothermic reaction heat generated in the bench scale SBCR, an effective cooling system was devised consisting of a U-type dip tube submerged in the reactor. Also, the physical and chemical properties of the catalyst were controlled so as to achieve high activity for the CO conversion and liquid oil ($C_{5+}$) production. Firstly, the FTS performance of the FeCuK/$SiO_2$ catalyst in the SBCR under reaction conditions of $265^{\circ}C$, 2.5 MPa, and $H_2/CO=1$ was investigated. The CO conversion and liquid oil ($C_{5+}$) productivity in the reaction were 88.6% and 0.226 $g/g_{cat}-h$, respectively, corresponding to a liquid oil ($C_{5+}$) production rate of 0.03 bbl/day. To investigate the FTS reaction behavior in the bench scale SBCR, the effects of the space velocity and superficial velocity of the synthesis gas and reaction temperature were also studied. The liquid oil production rate increased upto 0.057 bbl/day with increasing space velocity from 2.61 to 3.92 $SL/h-g_{Fe}$ and it was confirmed that the SBCR bench system developed in this research precisely simulated the FTS reaction behavior reported in the small scale slurry reactor.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.1
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• pp.12-18
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• 2007

The objective of the study was to compare ranking of Sahiwal bulls selected on the basis of highest lactation milk yield of their dams with their estimated breeding values (EBVs) using an animal model. Data on 23,761 lactation milk yield records of 5,936 cows from five main Livestock Experiment Stations in Punjab province of Pakistan (1964-2004) were used for the study. At present the young A.I bulls are required to be from A-category bull-dams. Dams were categorized as A, B, C and D if they had highest lactation milk yield of ${\geq}$2,700, 2,250-2,699, 1,800-2,249 and <1,800 litres, respectively. The EBVs for lactation milk yield were estimated for all the animals using an individual animal model having fixed effect of herd-year and season of calving and random effect of animal. Fixed effect of parity and random effect of permanent environment were incorporated when multiple lactation were used. There were 396 young bulls used for semen collection and A.I during 1973-2004. However, progeny with lactation yields recorded, were available only for 91 bulls and dams could be traced for only 63 bulls. Overall lactation milk yield averaged 1,440.8 kg. Milk yield was 10% heritable with repeatability of 39%. Ranking bulls on highest lactation milk yield of their dams, the in-vogue criteria of selecting bulls, had a rank correlation of 0.167 (p<0.190) with ranking based on EBVs from animal model analysis. Bulls' EBVs for all lactations had rank correlation of 0.716 (p<0.001) with EBVs based on first lactation milk yield and 0.766 (p<0.001) with average EBVs of dam and sire (pedigree index). Ranking of bulls on highest lactation yield of their dams has no association with their ranking based on animal model evaluation. Young Sahiwal bulls should be selected on the basis of pedigree index instead of highest lactation yield of dams. This can help improve the genetic potential of the breed accruing to conservation and development efforts.

• Journal of Korean Academy of Nursing
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• v.45 no.4
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• pp.554-564
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• 2015

Purpose: The purpose of this study was to develop and evaluate a self-management program based on INR monitoring for patients with cardiac valve replacement. Methods: This program was comprised of five weekly sessions based on Sousa's Enhance-Behavior Performance Model. The first session included individual teaching, and the other four sessions included Prothrombin Time International Normalized Ratios (PT INR) self-monitoring, telephone counseling and self-management checklist recording. Participants were patients who had cardiac valve replacement. They were randomly assigned to the experimental or control group. Sixteen in the experimental group participated in the self-management program and seventeen in the control group participated in general care. Self-management knowledge, self-efficacy, self-management behavior and PT INR were measured as dependent variables. Data were analyzed using Mann Whitney U-test, t-test and ANCOVA. Results: The experimental group showed significantly higher post-test scores in self-management knowledge (t=5.86, p<.001), self-efficacy (F=18.32, p<.001), and self-management behavior (t=3.44, p=.002) compared to the control group. Also, the experimental group showed significantly higher frequency in maintaining the treatment range of PT INR compared to the control group (${\chi}^2=4.80$, p=.028). Conclusion: The results of the research on the self-management program based on PT INR monitoring showed that it is effective in improving self-management knowledge, self-efficacy, and self-management behavior as well as maintaining treatment range of PT INR of patients with cardiac valve replacement.