• Biotechnology and Bioprocess Engineering:BBE
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• 제9권6호
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• pp.447-453
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• 2004

Optimal conditions for the supercritical carbon dioxide $(scCO_{2})$ extraction of glycyr­rhizin from licorice (Glycyrrhiza glabra) were investigated, with an emphasis on the types and levels of modifiers. The morphology of the licorice tissue remaining after the $scCO_{2} $ extraction of glycyrrhizin was examined by scanning electron microscopy, coupled with measurements of ab­solute density. Conventional organic solvent extraction was also carried out for purpose of quantitative comparison. At 50 MPa and $60^{circ}C$ glycyrrhizin could not be extracted with pure $scCO_{2}$, while a considerable amount of glycyrrhizin was extracted when water was added to $scCO_{2}$ as a modifier. The highest recovery was found to be about $97\%$ when $70\%$ aqueous methanol was added to $scCO_{2}$ at a concentration of $15\%$. The optimal pressure and temperature for the supercritical fluid extraction of glycyrrhizin were observed to be 30 M Pa and $60^{circ}C$, respectively. Under these conditions, the percentage recovery of glycyrrhizin attained a maximum value of 102.67\pm$ $1.13\%$ within 60 min. Furthermore, in the case of $scCO_{2}$ modified with $70\%$ aqueous methanol, the licorice tissue obtained after extraction was found to be severely de­graded by excessive swelling, and the absolute density of the licorice residues was observed to be the highest.

• Structural Engineering and Mechanics
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• 제5권4호
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• pp.399-414
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• 1997

This paper presents an investigation into the seismic response characteristics of a proposed ligh-weight pedestrian cable-stayed bridge made entirely from Glass Fiber Reinforced Plastics(GFRP). The study employs three dimensional finite element models to study and compare the dynamic characteristics and the seismic response of the GFRP bridge to a conventional Steel-Concrete (SC) cable-stayed bridge alternative. The two bridges were subjected to three synthetic earthquakes that differ in the frequency content characteristics. The performance of the GFRP bridge was compared to that of the SC bridge by normalizing the live load and the seismic internal forces with respect to the dead load internal forces. The normalized seismically induced internal forces were compared to the normalized live load internal forces for each design alternative. The study shows that the design alternatives have different dynamic characteristics. The light GFRP alternative has more flexible deck motion in the lateral direction than the heavier SC alternative. While the SC alternative has more vertical deck modes than the GFRP alternative, it has less lateral deck modes than the GFRP alternative in the studied frequency range. The GFRP towers are more flexible in the lateral direction than the SC towers. The GFRP bridge tower attracted less normalized base shear force than the SC bridge towers. However, earthquakes, with peak acceleration of only 0.1 g, and with a variety of frequency content could induce high enough seismic internal forces at the tower bases of the GFRP cable-stayed bridge to govern the structural design of such bridge. Careful seismic analysis, design, and detailing of the tower connections are required to achieve satisfactory seismic performance of GFRP long span bridges.

• 공업화학
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• 제18권1호
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• pp.41-47
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• 2007

Wyler법으로 제조된 구리프탈로시아닌(Cupc)을 kneader, attritor, SC-mill 및 acid pasting법으로 미분쇄하여 입자 크기, 모양, 결정구조를 비교하였다. Cupc 표준물질은 산업적으로 우수한 acid pasting, kneader법으로 제조하여 사용하였고, attritor, SC-mill로 분쇄한 후, 입도분석기, 전자현미경(SEM), X-선 회절스펙트럼(XRD)으로 입자특성을 분석하여 상호 비교하였다. SC-mill의 경우, 분쇄시간에 따라 입도분석기와 전자현미경으로 측정하였을 때, 90 min간의 분쇄시간 까지는 입자크기가 감소하였으나 그 이후부터는 Cupc의 강한 응집으로 평균입자크기가 증가하였다. Attritor로부터 건식 분쇄한 Cupc는 강한 응집에 의해 입도분석기로 입자크기를 측정할 수 없었지만, XRD peak intensity로부터 최적분쇄시간을 간접적으로 예측할 수 있었다.

• Journal of Animal Science and Technology
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• 제62권6호
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• pp.893-902
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• 2020

This study was conducted to compare the mRNA expression levels of myogenic-adipogenic makers in the skeletal muscle and adipocytes formation, body weight, rumen weight, and papilla length on Hanwoo calves at newborn and 6 months of age. Animals used three newborn Hanwoo calves (NC) and three Hanwoo calves 6 months of age (SC). Body weight and rumen weight were significantly increased in SC compared to NC (p < 0.01), and papilla length was longer about 10-fold in SC than NC. Adipocytes was possible to visually identify more adipocytes in SC compared to NC, and were mainly formed around the blood vessels. mRNA expression of myogenin, myosin heavy chain 1 and myosin heavy chain 2A in both longissimus dorsi (LD) and semimembranosus (SM) was found to increase with calves growth (p < 0.01), and it was confirmed that have higher levels of mRNA expression in SM than LD. In LD tissues, the mRNA expression of stearoyl-CoA desaturase (SCD, p < 0.03) and peroxisome proliferator activated receptor γ (PPARγ, p < 0.04) was significantly higher in SC than NC. In SM tissues, mRNA expression levels of SCD (p < 0.02) and CCAAT/enhancer binding protein β (C/EBPβ, p < 0.01) were higher in SC than NC, and also mRNA expression levels of PPARγ increased, but there was no significant difference. Thus, the calves period suggests that it is an important step in the development of the rumen and the myogenesis and adipogenesis.

• 공업화학
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• 제21권5호
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• pp.586-589
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• 2010

본 연구에서는 1,3-dicarbonyl 화합물과 올레핀 화합물의 산화첨가반응에서 $Ag_2CO_3$/celite (SC)를 촉매로 하여 1,3-cycleohexandion (1,3-CHD)과 ethyl vinyl ether (EVE)를 acetonitrile (AN), dimethyl sulfoxide (DMSO), benzene (BZ), heptane (HT)을 각각 용매로 하여 반응을 진행시켜 보았다. 그 결과 수득률이 78, 40, 15, 10%로 나타났다. 따라서 이러한 용매의 효과에 따른 수득률의 변화를 알아보기 위하여 하이퍼캠의 반경험적 방법으로 PM3와 ZINDO/1 파라미터를 이용하여 이론적 고찰을 해 보았다.

• 대한기계학회논문집B
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• 제35권4호
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• pp.431-438
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• 2011

비예혼합 화염의 부상 조건은 연소기의 운전 조건을 한정하는 매우 중요한 변수이다. 동축류 층류 비예혼합화염의 경우 점성계수와 물질 확산 계수의 비로 정의되는 슈미트 수가 1 보다 큰 조건에서 안정적인 부상화염이 존재하고 그 반대의 경우 부상이 불가능한 것으로 알려져 있다. 본 연구에서는 동축 관내에서의 화염의 부상 특성에 대해 슈미트 수가 1 보다 큰 프로판과 슈미트 수가 1 보다 작은 메탄 비예혼합 화염의 부상 안정화를 실험적으로 비교하였다. 그 결과, 제한된 공간에서는 슈미트 수가 1 보다 작은 조건에서도 안정적인 부상화염이 존재할 수 있음을 확인하였다. 그 원인 규명을 위해 간단한 비반응 유동장에 대한 수치해석을 수행하였다. 결론적으로 개방공간에서와는 달리 관내 조건에서는 유한한 크기의 화염 공간으로 인해 인접한 상류에서 유동 재편이 물질확산에 비해 선택적으로 재편됨으로써 새로운 안정화 기구가 형성될 수 있음을 확인하였다. 이러한 결과는 제한된 공간내에 화염이 형성되는 일반적인 연소기의 화염안정화 설명에 중요한 단서를 제공한다.

• The Journal of Korean Physical Therapy
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• 제26권1호
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• pp.1-8
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• 2014

Purpose: The aim of the present study was to understand the relationship between gait symmetry and functional balance, walking performance in stroke patients and to makes recommendation regarding the most suitable measure for standardization of expression of spatiotemporal gait symmetry. Methods: 45 subjects with stroke (31 men, 14 women, $57.3{\pm}10.3$ years old) participated in this study. Gait symmetry was calculated by equations of symmetry ratio (SR) and symmetry criterion (SC) for stance time, swing time, single leg support time (SLST), step length, and stride length. Spatiotemporal parameters were measured respectively by walkway system ($GAITRite^{TM}$ system). Limit of stability (LOS) by using forceplate (Balance Performance Monitor) during voluntary weight displacement and Berg Balance Scale (BBS) were measured as functional balance and Timed Up and Go test (TUG) and Functional Ambulation Category (FAC) were assessed as functional walking. Results: SR in stance time and swing time was correlation with BBS, TUG and FAC (p<0.05). SR in SLST only with BBS (p<0.01), SR in step length only with FAC (p<0.05). SC in stance time was correlation with BBS and TUG (p<0.05). SC in swing time and SLST with BBS, TUG and FAC (p<0.01), SC in step length with TUG and FAC (p<0.01), SC in stride length with BBS and FAC (p<0.01). Conclusion: Gait symmetry in spatiotemporal gait parameters provides meaningful information about functional balance and walking performance in stroke subjects. Our analysis may support the recommendations of the symmetry criterion as equation for standardization of gait symmetry.

• IMMUNE NETWORK
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• 제2권2호
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• pp.91-95
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• 2002

Background: In order to characterize human antibodies with specificity for mite allergens at the molecular level, a scFv phage display library was constructed using peripheral blood mononuclear lymphocytes from an asthma patient allergic to mite as Ig gene sources. Methods: Immunoglobulin $V_H$ and V gene fragments were obtained by polymerase chain reaction, and randomly combined in pCANTAB-5E vector. The resulting human scFv phage display library had $3{\times}10^4$ independent clones, and biopanning was performed with house dust mite extracts. Results: Four scFv clones specific for house dust mite extract were isolated. Immunoblot assay showed that our clones reacted to 25 kDa and 50~60 kDa proteins with unknown identity in mite extracts. Sequence analysis indicated that two clones (b7 and c15) are identical, and all clones belong to human $V_H3$ subgroup. On the other hand, light chain usage was different in that two clones (a2 and b7 / c15) belonging to V ${\kappa}4$ subgroup, but a4 used V ${\kappa}1$ light chain gene. Conclusion: Our approach should facilitate provision of useful information on the antibody responses against allergens at the molecular level in humans.

• Asian-Australasian Journal of Animal Sciences
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• 제22권4호
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• pp.550-556
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• 2009

This study was designed to evaluate the effects of dietary prebiotic (mannan oligosaccharide = MOS) and probiotic (Saccharomyces cerevisiae = SC) in finishing turkey diets on carcass, cut yield, meat composition and colour. A total of 72 ten-weeksold Big6 male turkey poults were used in the trial. There were eight replicate floor pens per floor with three birds in each. The experiment lasted up to 20 wks of age. The trial was set up as a completely randomized design with 3 dietary treatments. The treatments were: i) negative control (C, no additive); ii) MOS 1 g per kg of diet and iii) SC 1 g per kg of diet (strain SC47, $300{\times}10^{10}$ CFU/kg). Body weight (BW) and feed intake were determined for each of the two week intervals. Twenty-four birds were slaughtered and eviscerated to determine carcass, carcass parts and internal organ weights at 20 wks of age. Meat colour and pH levels were measured 24 h after slaughter. The dietary treatments did not affect BW and average daily gain during the trial (p>0.05). The average daily feed intake and feed conversion ratio of turkey toms fed with MOS were higher than those of control and SC groups during the overall period (p<0.05). The dietary treatments did not affect carcass yield, breast meat, thigh, wing, liver, heart, empty gizzard, intestine, and abdominal fat pad proportions and meat pH, composition and pigmentation (p>0.05). These results suggest that the addition of MOS and SC is not likely to produce any performance or carcass characteristics in finishing turkeys at 10 to 20 wks of age.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2008년도 International Meeting of the Microbiological Society of Korea
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• pp.62-64
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• 2008

A major hurdle to the development of RNA interference as therapy for HIV infection is the delivery of siRNA to T lymphocytes which are difficult cells to transfect even in vitro. We have employed a single chain antibody to the pan T cell surface antigen CD7 was conjugated to an oligo-9-arginine peptide (scFvCD7-9R) for T cell-specific siRNA delivery in NOD/SCIDIL2${\gamma}$-/- mice reconstituted with human peripheral blood lymphocytes (Hu-PBL). Using a novel delivery, we first show that scFvCD7-9R efficiently delivered CD4 siRNA into human T cells in vitro. In vivo administration to Hu-PBL mice resulted in reduced levels of surface CD4 expression on T cells. Mice infected with HIV-1 and treated on a weekly basis with scFvCD7-9R-siRNA complexes targeting a combination of viral genes and the host coreceptor molecule CCR5 successfully maintained CD4/CD3 T cell ratios up to 4 weeks after infection in contrast to control mice that displayed a marked reduction in CD4 T cell numbers. p24 antigen levels were undetectable in 3 of the 4 protected mice. scFvCD7-9R/antiviral siRNA treatment also helped maintain CD4 T cell numbers with reduced plasma viral loads in Hu-PBL mice reconstituted with PBMC from donors seropositive for HIV, indicating that this method can contain viral replication even in established HIV infections. Our results show that scFvCD7-9R could be further developed as a potential therapeutic for HIV-1 infection.