• Parasites, Hosts and Diseases
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• v.34 no.3
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• pp.161-168
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• 1996

We observed the morphological characteristics and identified the species of gnathostome larvae obtained from the imported Chinese loaches. The early third-stage larvae ($EL_3$) were collected from viscera of the loaches and a part of them were infected to mice. The advanced third-stage larvae ($AdL_3$) were recovered from the mice at 4 weeks post-infection. both larval worms were fixed loth 10% formalin, cleared in alcohol-glycerin solution, mounted with glycerin-jelly, and observed. A total of 369 $EL_3$ were collected from viscera of 9,493 Chinese loaches. The whole body of $EL_3$ was covered with about 190 transverse rows of minute cuticular spines and $0.624{\;}{\times}{\;}0.101{\;}mm$ in average size. A pair of lips were protruded at the anterior end, and the muscular esophagus and brownish intestine were followed. The characteristic head bulb was provided with 4 rows of hooklets. The average number of hooklets in the respective row was 36.7, 39.5, 41.6 and 44.3 posteriorly $AdL_3$ was $2.660{\;}{\times}{\;}0.346{\;}mm$ in average size, and retained the esophagus (about 0.755 mm length) and cervical sac (about 0.355 mm length). The average number of hooklets in the respective row on the head bulb was 39.0, 41.9, 43.9 and 45.6, posteriorly. On the basis of the morphological characteristics, they were identified as the third-stage larvae of Gnathostomc hispinun.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.528-534
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• 2020

The early development and use of plate heat exchangers (PHE) were in response to stringent statutory requirements from dairy products in the late 19th century, but PHEs were not exploited commercially until the 1920s. Since then, although the basic concept of PHEs has changed little, its design and construction have progressed significantly to accommodate higher temperatures and pressures, as well as large heat exchanging capacities. The development of current chevron-type corrugated heat plates has been ongoing since the oil shock in the 1970s to improve energy efficiency. The development trend of PHEs is consistent with the development of larger heat plates with better thermal efficiency, lower pressure drop, and good flow distribution. In this study, the thermal performance of small heat plates (PHE-S) and large heat plates (PHE-L) with the same plate depth and corrugation pitch were analyzed experimentally for each channel (H, M, and L type) to suggest development directions of heat plates. The test results showed that for the convectional heat transfer coefficient, the PHE-S was on average, 16.5% higher in the H type, 25% higher in the M type, and 40% higher in the L type than PHE-L. In the case of the pressure drop, the PHE-S was 19% higher in the H type, 46% higher in the M type, and 61% higher in the L type than PHE-L. These results were attributed to the differences in fluid distribution areas between the PHE-S and PHE-L, among other potential causes.

• Journal of Life Science
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• v.28 no.4
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• pp.408-414
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• 2018

Actein is the well-known active ingredient of Cimicifugae rhizoma (Black cohosh). In this study, we investigated and compared the binding affinity of tubocurarine, actein, and actein derivatives on the B&C domain of the acetylcholine binding protein through in silico computational docking studies. The three-dimensional crystallographic structure of the acetylcholine binding protein B&C domain was obtained from the PDB database (PDB ID: 2XYT). An in silico computational autodocking analysis was performed using PyRx, Autodock Vina, Discovery Studio Version 4.5, and NX-QuickPharm based on scoring functions. The actein showed an optimum binding affinity (docking energy), with the acetylcholine binding protein at -10.50 kcal/mol as compared to the tubocurarine (-9.80 kcal/mol). The interacting amino acids tryptophan 84 and tryptophan 147, in the B domain of the acetylcholine binding protein active site, significantly interacted with the actein and 27-deoxyactein, and (26R)-actein. The centroid XYZ grid position of the tubocurarine was X=38.300689, Y=112.053467, and Z=51.991022, but the actein and its derivatives showed values around X=26.4, Y=127.3, Z=43.7. These results clearly indicated that actein and its derivatives could be a more potent antagonist to the acetylcholine binding protein than tubocurarine. Therefore, the extract of Cimicifugae rhizoma or actein containing biomaterials can substitute for the botulinum toxin-mediated acetylcholine receptor regulation, and be applied to the anti-wrinkle cosmetics industry.

• Applied Microscopy
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• v.40 no.4
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• pp.245-251
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• 2010

In this study, we applied 15% glycolic acid peeling agent and 30% glycolic acid peeling agent to the dorsal skin of mice and analyzed the oil content, moisture content, and pH value of the skin before and after test using cutometer. Ultrastructure for changes in the epidermis of mice were observed under a dermoscope and a scanning electron microscope before and after test. When using 15% glycolic acid peeling agent, the changes of moisture content was measured 74.67 AU for the normal control group and 70.21 AU for the experimental group, the oil content was 13.49 mg/$cm^2$ for the normal control group before test and 8.25 mg/$cm^2$ after test, and the pH value was 6.70 and 5.36 before and after test, respectively. When using 30% glycolic acid peeling agent, the moisture content was measured 74.46 AU for the normal control group before test and 53.50 AU for the experimental group after test, the oil content was 13.82mg/$cm^2$ and 5.70 mg/$cm^2$ before and after test, and the pH value was 6.45 and 4.58 before and after test, respectively. As such, it was found that the changes of moisture and oil content on the skin rely on the concentration of peeling agent and the degree of exfoliation of keratin. The surface of stratum corneum of mice with application of 15% glycolic acid peeling agent was relatively smooth and the exposed cellular surface of keratinocyte had some wrinkles. The surface of stratum corneum of mice with application of 30% glycolic acid peeling agent was smooth. No wrinkles were observed under high-resolution scanning electron microscope.

• Journal of Chest Surgery
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• v.32 no.1
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• pp.5-9
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• 1999

Background: Ebstein anomaly is a rare congenital disease distinguished by its unique deformity in tricuspid valve and right ventricle & atrium. In its surgical treatment , tricuspid valve reconstruction and valve replacement are well known method, but various surgical methods were suggested. Material and Method : From January 1984 to December 1995, 8 patients with Ebstein anomaly underwent surgical correction. Age and sex distribution, clinical symtoms, radiologic findings, preoperative studies, operative findings, operative methods and its results were analyzed. Result: The sex ratio was 5 to 3(male : female). Patients' ages were averaged 17.6(2-28) years. In all cases, it showed typical deformities of the tricuspid valve. Associated anomalies were permenant foramen ovale, atrial septum defect, pulmonary stenosis. Surgical procedures included tricuspid valve replacement(n=4) and tricuspid valve reconstuction(n=4). Two cases of sinus tachycardia and complete AV block occured postoperatively. There were two hospital death and no late death. All survivors are in NYHA class I or II with median follow up of 64.8 months. 2-D echocardiogram disclosed improvement tricuspid regurgitation during the follow up period. Conclusion: Even though operative method of Ebstein anomaly should be decided according to each anatomical characteristics, we recommended that tricuspid valvuloplasty and plication can be one of the good methods method in the selective cases.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.2
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• pp.129-136
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• 2010

In order to evaluate anti-wrinkle activity of Carex humilis extract, free radical scavenging activity, elastase inhibitory activity and reduction of expression Matrix metalloproteinase-1 (MMP-1) mRNA and MMP-1 protein were investigated. The roots of Carex humilis were extracted with 95 % ethanol and successively partitioned with organic solvents with increasing polarity of the solvents. Each fraction of organic solvent were investigated by using free radical scavenging activity and elastase inhibitory activity test. Among them, EtOAc fraction showed antioxidant activity ($SC_{50}$=4.89 ${\mu}g/mL$) and elastase inhibitory activity ($IC_{50}$=23.5 ${\mu}g/mL$). EtOAc fraction was developed on silica gel by open-column chromatography and consecutively re-developed on C18 resin by prep-HPLC to give ${\alpha}$-viniferin as a major component, which was confirmed by spectrometric analysis. In the assay on expression of MMP-1 mRNA by RT-PCR and protein by western-blot, EtOAc layer (10 ~ 100 ${\mu}g/mL$) was reduced about 50 ~ 60 %, 50 ~ 65 % respectively and ${\alpha}$-viniferin (0.5 ~ 2 ${\mu}g/mL$) was inhibited about 60 ~ 75 %, 55 ~ 65 % respectively in human fibroblast. Therefore, our findings suggest that EtOAc layer of Carex humilis containing ${\alpha}$-viniferin can be useful as an active ingredient for cosmeceuticals of anti-wrinkle effects.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.7
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• pp.865-873
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• 2013

The deep drawing and ironing (DDI) process involving the use of a high-capacity horizontal press is used for manufacturing acompressed natural gas (CNG) pressure vessel. However, some variables of the DDI process have been determined based on the experiences of workers, and the short die life needs to be improved for manufacturing the pressure vessel withhighquality and lowcost. In this study, process variables such as the draw ratio, distance between dies, radius of rounding of drawing die, and angle of ironing die are chosen to enhance the reliability and improve the die life based on previous studies and experiences. The draw ratio limits at which no tearing or wrinkling occurs are determined using FEA, and the distances between dies, radius of rounding of drawing die, and angle of ironing die are optimized by the DOE method. The results of the optimal process variables are compared with those of the existing DDI process for verifying their effectiveness.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4087-4092
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• 2014

The gangway connection of the articulated high speed railway vehicles (HSRV) is a double wrinkled rubber component to seal the air of the corridor under a range of angular deviations between the carriage end parts. From the results of non-linear structural analysis, one of the severe loading conditions for the connection is mixed mode (rolling+yawing) angular displacements while passing through the small-radius curved siding track of the HSRV depot. In this study, to ensure the safety enhancement of the component, the optimal design for the cross section of that was performed using the Solid Isotropic Material with Penalization (SIMP) method. Nonlinear finite element analysis confirmed that the decreases in the maximum principal strain of the optimized design under rolling and mixed modes are 68% and 39%, respectively, compared to the initial design.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.150-150
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• 2016

디스플레이, 센서 등 전자소자는 소형화 단계를 지나 인체 부착형 소자로의 발전을 요구하고 있다. 부착형 소자에서는 접착력과 큰 마찰력이 필요하지만 마찰특성이 더 중요하므로 인체 및 물체의 마찰을 위해서는 다양한 표면에 대항하는 마찰 특성과 내구성이 요구되며 이를 위해 개코도마뱀 또는 딱정벌레, 말벌날개와 같은 자연모사형 건식 마찰 방식에 대한 연구가 활발히 진행되고 있다. 그러나 기존 폴리머를 이용하여 자연모사형 마이크로/나노 구조 형성은 기계적으로 가공된 금형 몰딩을 통한 매무 복잡한 공정을 요구된다. 본 연구에서는 이러한 복잡한 공정을 통한 마찰재 제작을 단순화하기 위해서 플라즈마 표면처리를 활용하여 나노구조 형성하는 방법을 소개하고자 하며, 건식 접착 및 마찰용 폴리머 소재(PDMS(Poly dimethyl siloxane))에 따른 표면구조 변화와 표면에너지 및 화학결합 변화에 대한 연구를 수행하였다. 플라즈마 표면처리를 위해서 자체 개발한 선형이온소스를 활용하였으며 입사에너지에 따라 표면형상 변화를 주사전자현미경을 활용하여 관찰하였다. 표면에너지 변화는 접촉각측정기를 활용하였으며, Tribology tester(Ball on disk)를 활용하여 마찰특성을 평가하였다. PDMS(Poly dimethyl siloxane)는 입사에너지가 증가함에 따라 주름형태 구조 크기가 증가하는 것을 관찰하였고, 플라즈마 처리를 통해 표면에너지 및 마찰력 증가를 관찰하였다. 그리고 플라즈마 처리 후 표면에너지 변화인 FOTS(Trichloro-(1H,1H,2H,2H- perfluorooctyl) silane) 처리를 통하여 표면에너지 감소와 마찰력이 절반으로 감소하였다. 본 연구 결과는 나노구조에 따라 표면형상 및 표면에너지 변화에 따른 PDMS의 마찰력 변화를 확인하였고, 이러한 특성을 활용하여 마찰재와 피부 부착형 접착 패치에 응용이 가능할 것으로 기대된다.

• Polymer(Korea)
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• v.26 no.3
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• pp.326-334
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• 2002

The purpose of this work was the producing of a biodegradable poly($\varepsilon$-caprolactone) (PCL) microcapsule and the analyzing of form and features for the manufacturing conditions which could be observed in a prospective drug delivery systems (DDS) through drug release. The effects of different stirring rates, stirring times and concentrations of emulsifier for the diameter and form of the microcapsules were observed using image analyzer (IA) and scanning electron microscopy (SEM). As a result, the microcapsules were made in wrinkle and spherical forms with a mean particle size of 40~300$\pm$20 $mu extrm{m}$. PCL microcapsules containing drugs were confirmed using FT-IR spectra. The role of interfacial adhesion between PCL and drug was determined by contact angle measurements. The drug release test of PCL microcapsules was characterized by UV/vis. spectra. It was found that the drug release rate of the microcapsules prepared with high concentration emulsifier was significantly fast.