• Journal of Microbiology and Biotechnology
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• 제29권4호
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• pp.571-576
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• 2019

Microenvironmental stress, which is naturally observed in solid tumors, has been implicated in anticancer drug resistance. This tumor-specific stress causes the degradation of topoisomerase $II{\alpha}$, rendering cells resistant to topoisomerase $II{\alpha}$-targeted anticancer agents. In addition, microenvironmental stress can induce the overexpression of 78kDa glucose regulated protein (GRP78), which can subsequently block the activation of apoptosis induced by treatment with anticancer agents. Therefore, inhibition of topoisomerase $II{\alpha}$ degradation and reduction in GRP78 expression may be effective strategies for inhibiting anticancer drug resistance. In this study, we investigated the active compound arctigenin, which inhibited microenvironmental stress-induced etoposide resistance in HT-29 cells. Arctigenin was also highly toxic to etoposide-resistant HT-29 cells, with an $IC_{50}$ value of $10{\mu}M$ for colony formation. We further showed that arctigenin inhibited the degradation of topoisomerase $II{\alpha}$ and reduced the expression of GRP78. Thus, these results suggest that arctigenin is a novel therapeutic agent that inhibits resistance to etoposide associated with microenvironmental stress conditions.

• 통합자연과학논문집
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• 제12권2호
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• pp.47-57
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• 2019

Staphylococcus epidermidis is well-known not only as an innocuous normal flora species commonly isolated from human skin, but also as an important bacterial species to keep skin healthy, because this species can protect the human skin from pathogenic microorganisms. However, S. epidermidis turns into a potential pathogen in damaged skin, because these bacteria can easily form a biofilm on the wound area and provide antimicrobial resistance to other microorganisms embedded in the biofilm. Thus, it is important to kill S. epidermidis in the early stage of wound treatment and block the formation of biofilms in advance. In the present study, hydrogel wound dressings were fabricated using polyvinyl alcohol/polyethylene glycol containing silver citrate nanorods, which have been proven to have strong antimicrobial activity, especially against S. epidermidis, and their wound-healing efficacy was investigated in vivo using a rat experiment.

• 건축역사연구
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• 제31권1호
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• pp.61-76
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• 2022

Bongik-dong, Kwonnong-dong, Ikseon-dong and Nakwon-dong are areas around Donhwamun-ro in Seoul. These residential areas began to be developed collectively from the 1920s and the construction period was the fastest among hanok residences collectively formed in urban center. At that time, houses were developed with high density. In the 1920s, many medium-sized plots of less than 3,300m² were distributed around Donhwamun-ro. Private developers such as Jeong Se-kwon(Konyangsa), Shin Tae-jong, and Yoon Heung-rim, who were active at the time, purchased medium-sized plots. Developers sold out the land directly or after constructing Hanok on the divided plot and then selling them. This method of developing hanok residences by private developers in the 1920s have influenced on hanok residences which began to be developed after the 1930s. Currently, many urban Hanoks still remain in areas around Donhwamun-ro. The initial aspects of the hanok development in the 1920s could be grasped through blocks, plot division, alleys, row house Hanok etc around Donhwamun-ro.

• 대한의생명과학회지
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• 제29권4호
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• pp.242-248
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• 2023

Platelets are activated at the sites of vascular injury by a number of molecules, including adenosine diphosphate, collagen and thrombin. The full platelet aggregation is absolutely essential for the normal hemostasis. Glycyrrhiza glabra is a well-known medicinal herb that grows in various parts of the world and is known to have various effects such as antioxidant, anti-inflammatory, anti-atherogenic, anti-osteoporotic and skin-whitening. However, the platelet inhibitory effect of Glycyrrhiza glabra extract (GGE) has not been identified. In this study, we investigated if GGE inhibited platelet aggregation. We observed that GGE inhibited collagen-induced platelet aggregation, Ca²⁺ mobilization, and thromboxane A2 generation. In addition, GGE suppressed phosphorylation of phosphatidylinositol-3 kinase (PI3K), Akt and elevated phosphorylation of inositol 1,4,5-trisphosphate receptor (IP3R), vasodilator stimulated phosphoprotein (VASP). Taken together, GGE showed strong antiplatelet effects and may be used to block platelet-mediated cardiovascular diseases.

• Tribology and Lubricants
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• 제40권1호
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• pp.24-27
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• 2024

A monotype valve body for a dual clutch transmission has the potential to reduce costs, weight, and manufacturing time by modularizing various parts, including those of existing solenoid packs and valve bodies, into one through the application of super-precision die casting technology. However, this approach may lead to challenges such as reduced rigidity and increased interference due to modularization and compactness, impacting both product performance due to the reduced weight as well as durability and reliability. Unlike existing products, this approach requires a high-precision thin-wall block to avoid more complicated flow line formation, interference between flow lines, and leaks, as well as a strict quality requirement standard and precise inspections including detection of internal defects. To conduct precise inspections, we built an equivalent model corresponding to a driving distance of 300,000 km. Testing involved simulating actual road loads using a real vehicle and a chassis dynamometer in the FTP-75 mode (EPA Federal Test Procedure). The aim of the study was to establish a vehicle load-based part durability model for manufacturing a mono-type valve body and to develop fundamental technology for part weight reduction through preliminary design by introducing analytical weight reduction technology based on the derived results.

• 지식경영연구
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• 제21권3호
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• pp.45-65
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• 2020

가치가 상승하는 와인에 투자하는 것은 바람직하지만 우리나라에서는 와인 투자 자체가 생소하다. 또한, 와인시장에서의 가격책정은 소수에 의해 이루어지기 때문에 과정 자체가 비합리적이고, 정보가 위조되는 경우가 흔하다. 그러나 올바른 해결책만 있다면 와인시장은 오래 투자할수록 높은 수익을 기대할 수 있다는 점에서 바람직한 투자처가 될 수 있다. 또한, 국내 와인수입량의 꾸준한 증가추세를 통한 국내 와인 소비시장의 확대 또한 기대된다. 본 연구는 앞서 말한 우리나라의 와인 투자 시장의 '올바른 해결책'으로 와인시장 활성화 및 투명성 제고를 위한 컨소시엄 블록체인 프레임워크를 제시한다. 블록체인 거버넌스는 바람직한 의사결정권과 책임성을 보장하기 때문에 와인시장의 단점을 보완해줄 수 있다. 블록체인에 저장된 데이터는 소비자가 모두 확인할 수 있기 때문에 위조와인의 등장 가능성을 낮추고 불합리적으로 가격이 책정되는 과정을 보완한다. 또한 자산의 디지털화로 낮은 현금유동성을 해결하며 스마트 컨트랙트를 통해 공급망 전반의 비용과 시간을 절약하게 되어 와인투자의 진입장벽이 낮아진다. 특히 컨소시엄 블록체인을 통해 블록체인의 거버넌스를 '샤또-유통업자-투자자'로 구성한다면 바람직한 와인 시장을 형성할 수 있다. 생산과정을 블록체인에 저장하여 생산비용을 확보하고 합리적인 출시가를 정하며 유통과정을 블록체인에 저장하여 물류시스템을 효율적으로 운영하고 선물거래 주문량을 예측한다. 마지막으로 투자자들은 이 모든 데이터를 열람함으로써 합리적인 의사결정을 한다. 이는 와인경매시장에 있어서 주요 이해관계자들간의 지식공유체제로서 작동할 수 있는 가능성을 제시하고 있다. 해당 연구에서는 소유권을 주식처럼 다룰 수 있다는 점에서 대체투자의 새로운 관점을 제시했다. 또한 정보의 투명성을 제고시킬 방안으로써 와인 소유 매매 프레임워크를 제시하였고 식품 수입절차의 간소화와 와인 업계 내 신뢰 형성을 가능하게 했다. 해당 프레임워크를 통해 와인 관련 정보들을 투명하게 기록함으로써 활발한 와인투자가 이루어질 수 있을 것이며 이는 지식경영 측면에서 큰 의의를 가진다. 향후 연구에서는 해당 프레임워크를 확장해 적용할 분야를 연구하고자 한다.

• Clinical and Experimental Reproductive Medicine
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• 제28권1호
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• pp.41-46
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• 2001

Objective: To determine the effects of leukemia inhibitory factor (LIF) on embryonal development in in vitro culture. Methods: This is designed in vitro model using eggs from mouse. The eggs from mouse were assigned 29 for control group, 53 for 20 ng/ml of LIF, 88 for 40 ng/ml of LIF, 68 for 80 ng/ml of LIF respectively for in vitro fertilization. And 26 fertilized eggs at 2 cell stage from mouse also were assigned. The mouse embryos of all groups were cultured in medium supplemented with LIF in different concentrations, whereas the eggs in control group was cultured in medium without supplement of LIF. Results: At 72 hours culture of eggs from in vitro fertilization, there was a slight increas in rate of embryonal development to morula in both LIF-20 and LIF-40 as results of 64.15% and 75% respectively, while 42.65% in inferior rate of LIF-80, compare with 51.72% in control group. But the difference between these each groups were not significant in statistically ($p{\le}0.05$). And after 96 hours culture of eggs, the rates blastocyst formation was significantly higher in both LIF-20 and LIF-40 as 56.6% and 63.63% than those in control and LIF-80 as 44.83% and 35.29% respectively. On culturing eggs from in vivo fertilization, the rates of blastocyst formation was significantly not only higher as 85% and 81.81% respectively in medium supplemented with LIF-40 and LIF-80 than 42.3% in LIF-20 but also embryonal cell viability were remakedly improved at 96 hours after culture. Conclusion: The LIF in low dose is embryotrophic, but LIF in high dose is embryotoxic on eggs from in vitro fertilization. Whereas on culturing eggs from in vivo fertilization, LIF is more beneficial with dose dependent in high concentration.

• 지구물리
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• 제3권1호
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• pp.1-12
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• 2000

경상분지내 밀양소분지의 건천리 지역에 분포하는 백악기 하양층군의 송내동층, 채약산화산암, 건천리층, 그러고 유천층군 하부인 주사산안산암을 대상으로 지층생성 당시의 자북의 위치와 퇴적시기를 결정하기 위하여 12개 노두에서 106개의 정향시료 채취하여 고자기 연구를 수행하였다. 연구결과 주 자성광물인 적철석과 자철석에 의하여 기록된 이들 지층들의 평균 특성잔류자기 방향은 역전검사 그리고 통계학적으로 99%의 신뢰도를 가지며 습곡검사 통과하였다. 단계적 습곡검사에서는 군집지수 k값의 변화가 90%의 지층경사보정 단계에서 최대를 보여서 이들 지층들의 특성잔류 자기는 지층경사나 습곡작용 이전 즉, 퇴적 동시기이거나 그 직후에 획득된 1차 잔류자기임을 지시한다. 이들의 평균 방향과 고자기극의 위치는 각자 $D=22.9^{\circ},\;I=59.1^{\circ}\;(k=410,\;{\alpha}_{95}=3.0^{\circ},\;N=7sites)$와 $199.6^{\circ}E,\;71.6^{\circ}N\;(K=206.9,\;A_{95}=4.2^{\circ})$이다. 이는 중국대륙 및 경상분지내 다른 동시대 지층들에서 구한 방향들과 오차한계 내에서 동일한 것으로서 연구지역과 이들 지역간에 상대적 변위나 수평회전운동이 거의 없었음을 지시한다. 자기층서학적 견지에서 볼 때, 연구지층들은 백악기 상부 알비안(upper Albian)에서 하부 캄파니안(lower Campanian)의 역자극기까지의 것으로 대비된다. 한편, 채약산화산암과 주사산안산암의 응회암과 및 각력암에서는 분산된 특성잔류자기 방향이 나타났는데 이는 암석들이 잔류자기를 획득한 후에 화산함몰 구조운동에 의하여 재동(reworked)되었음을 의미한다.

• Archives of Plastic Surgery
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• 제33권3호
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• pp.347-352
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• 2006

Ingrowing toenail has been treated conventionally by various surgical treatment modlities. However, none of these procedures are perfect to achieve esthetic results with low cost, recurrence, and complication rates. Although mild cases can be treated conservatively, in severe recurrent cases, surgical treatment is preferred. The purpose of this study is to evaluate the effectiveness and safety of using partial matricectomy and paronychial advancement flap for correction of recurrent ingrowing toenail. Eight patients suffering from recurrent ingrowing toenail were operated using partial matricectomy and paronychial advancement flap in our department from August 2004 to August 2005. The number of recurrent episodes ranged from 2 to 5. With digital nerve block, the excision area was marked on nailplate and inflammed lateral nail fold. The horizontally designed paronychial flap considering defect size was effective for wide exposure of the neighboring germinal matrix, which is later to be completely excised or cauterized because remnant germinal matrix made postoperative spicule formation. The nailplate on the affected side was removed about 3-5 mm width longitudinally, being cautious not to damage the proximal dorsal nail fold. The same width of the sterile matrix including germinal matrix was excised longitudinally with inflammed granulation tissue and partial lateral nail fold on the affected side. The subcutaneously elevated paronychial flap was advanced to cover the defect and was anatomically sutured with 5-0 nylon sutures. We evaluated our procedure's effectiveness by examining some factors such as cosmetic results, recurrence, spicule formation, postoperative pain and duration of return to normal activities. In eight patients, no complication was observed such as recurrence, severe pain and spicule formation except for 1 case of infection. Postoperative discomfort was minimal. Average duration of return to normal activities was 12 days. Cosmetically the results were acceptable in all patients. The partial matricectomy and paronychial advancement flap for correction of recurrent ingrowing toenail were found to be technically simple, efficient procedure with a relative low recurrence rate and better cosmetic results.

• 대한화장품학회지
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• 제34권3호
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• pp.217-223
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• 2008

피부에서 엘라스틴(elastin)은 중요한 탄력섬유의 구성성분 중의 하나이다. 피부주름(skin wrinkle) 형성은 콜라겐(collagen)의 합성과 분해가 중요한 요인으로 작용한다고 알려져 있지만, 최근 많은 연구에서 엘라스틴의 재형성과 분해 또한 주름형성 기전에서 중요한 작용을 하는 것으로 보고되고 있다. 엘라스타제(elastase)는 엘라스틴을 분해하는 일종의 메탈로프로테이나제(metalloproteinase)이며, 자외선 B (ultraviolet B, UVB) 조사 후에 활성이 증가하는 것으로 알려져 있다. 따라서 증가된 엘라스타제의 활성은 피부의 탄력성 감소와 주름 형성의 주요한 원인이 될 것이다. 본 연구에서는 항산화 효과가 있으며, 각종 견과류나 과일에 함유된 폴리페놀(polyphenol)성분인 탄닌산(tannic acid)을 사람의 섬유아세포(CCD-25Sk fibroblasts)에 처리하여 엘라스타제 활성과 트로포엘라스틴 생성에 미치는 영향을 조사하였다. 탄닌산은 농도의존적으로 사람의 섬유아세포 엘라스타제 활성을 유의성 있게 억제시켰다. 그러나 트로포엘라스틴 합성이나 발현증가에는 유의성 있는 효과를 보이지 않았다. 이러한 결과들로부터 탄닌산은 엘라스타제의 활성을 억제시켜 엘라스틴의 3차원적 구조를 유지하는데 기여하는 것으로 사료된다. 따라서 탄닌산은 주름생성을 억제하는 물질로 개발 가능할 것으로 기대된다.