Control of Reversible Self-Bending Behavior in Responsive Janus Microstrips

Oh, Myung Seok,Song, Young Shin,Kim, Cheolgyu,Kim, Jongmin,You, Jae Bem,Kim, Taek-Soo,Lee, Chang-Soo,Im, Sung Gap American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.13

<P>Here, we demonstrate a simple method to systematically control the responsive self-bending behavior of Janus hydrogel microstrips consisting of a polymeric bilayer with a high modulus contrast. The Janus hydrogel microstrips could be easily fabricated by a simple micromolding technique combined with an initiated chemical vapor deposition (iCVD) coating, providing high flexibility in controlling the physical and chemical properties of the microstrips. The fabricated Janus hydrogel microstrip is composed of a soft, pH-responsive polymer hydrogel layer laminated with a highly cross-linked, rigid thin film, generating a geometric anisotropy at a micron scale. The large difference in the elastic moduli between the two layers of the Janus microstrips leads to a self-bending behavior in response to the pH change. More specifically, the impact of the physical and chemical properties of the microstrip on the self-bending phenomena was systematically investigated by changing the thickness and composition of two layers of the microstrip, which renders high controllability in bending of the microstrips. The curvature of the Janus microstrips, formed by self-bending, highly depends on the applied acidity. A reversible, responsive self-bending/ unbending exhibits a perfect resilience pattern with repeated changes in pH for 5 cycles. We envision that the Janus microstrips can be engineered to form complex 3D microstructures applicable to various fields such as soft robotics, scaffolds, and drug delivery. The reliable responsive behaviors obtained from the systematic investigation will provide critical information in bridging the gap between the theoretical mechanical analysis and the chemical properties to achieve micron-scale soft robotics.</P>

적층각 변화에 따른 복합재료 회전익의 구조적 연성에 관한 연구

변창환,유용석,오택열 경희대학교 산학협력기술연구원 1997 산학협력기술연구논문집 Vol.3 No.-

This study is made allowance for using one dimensional modeling method that extracts equivalent stiffness matrix used the reduction of degree of freedom in order to sufficiently express the cross section of rotor blade and the material properties of composite. Modern helicopter rotor blade which are made from anisotropic material is very important a subject on the tailoring based on coupling tearms by changing of ply angle. In basing on this, we have searched for coupling terms by changing of ply angle of composite rotor blade and the dynamic behaviour of rotor blade for each coupling term.

Electro-hyperthermia up-regulates tumour suppressor Septin 4 to induce apoptotic cell death in hepatocellular carcinoma

Jeon, Tae-Won,Yang, Heebum,Lee, Chang Geol,Oh, Sang Taek,Seo, Daekwan,Baik, In Hye,Lee, Eun Hye,Yun, Ina,Park, Kyung Ran,Lee, Yun-Han Informa UK (TaylorFrancis) 2016 International journal of hyperthermia Vol.32 No.6

<P>Purpose: Modulated electro-hyperthermia (mEHT) has been shown to be effective against various types of human tumours, including hepatocellular carcinoma (HCC). Here we aimed to investigate the molecular mechanism underlying the cytotoxic effects of mEHT to HCC cells. Materials and methods: Human liver cancer cell lines, Huh7 and HepG2, were treated with mEHT (42 degrees C/60 min) three times at 2-day intervals. Growth inhibition and apoptotic induction were evaluated using MTS, microscopic analysis, a clonogenic assay, annexin V/PI staining and a ccK18 ELISA. Global changes in gene expression were examined using RNA sequencing to obtain insights into molecular changes in response to mEHT. For in vivo evaluation of mEHT we used HepG2 HCC xenografts grown in nude mice. Results: mEHT suppressed HCC cell proliferation and long-term colony formation through induction of apoptosis. The growth inhibitory effects are induced through a subset of molecular changes. Notably the expression level of septin 4 (SEPT4) (involved in pro-apoptotic activity and growth suppression) was up-regulated, whereas a key regulator of invasiveness G-Protein coupled receptor 64 (GPR64) was repressed. Subsequent Western blotting confirmed that the common increase in tumour suppressor SEPT4 in both Huh7 and HepG2 cells is accompanied by the restoration of cyclin-dependent kinase (CDK) inhibitor p21 and decrease in pro-caspase 7 and pro-caspase 3, thereby accelerating apoptotic signalling in HCC cells. Additionally, mEHT significantly inhibited the growth of human HCC xenografts in nude mice. Conclusions: These findings suggest that apoptotic cell death induced by mEHT is mediated by the up-regulation of tumour suppressor SEPT4 in human HCC cells.</P>

R&D 투자 영향평가 기반 구축 및 시범분석

황석원(Seog-Won, Hwang),오승환(Seung-Hwan, Oh),우청원(Ceung-Won, Woo),장필성(Pil-Seoung, Jang),홍사균(Sa-Gyun, Hong),강희종(Hee-Jong, Kang),최창택(Chang-Taek, Choi),김기환(Gi-Hwan, Kim),이재진(Jae-Jin, Lee),김지훈(Ji-Hoon, Kim) 과학기술정책연구원 2016 정책연구 Vol.- No.-

This study is a late study of “An Exploratory Study on STI policy impact assessment”. In the research of 2015, in principle, it is necessary to evaluate not only R&D investment but also general policies such as various promotion systems, standards and regulations by putting the term “policy impact assessment” in front of it We emphasized the points. However, it is practically very difficultto collect and analyze detailed data of all STI policies. In addition, it is also restricted to allow policy researchers to access data within a certain range. Therefore, this study focuses on the impact assessment of R&D investment, which accounts for the largest percentage of STI policies. In this research, the impact assessment system of R&D investment is analyzed by classifying it into evaluation of economic impact and social impact assessment. Also, the evaluation of economic impact was analyzed separating into a micro viewpoint and a macro viewpoint. First, The analysis of the economic impact assessment of the micro viewpoint relates to how the government’s R&D investment affects enterprises. Specifically, the main analysis target was the employment and investment of companies, the impact on sales and profits. Second, The Analysis for macroeconomic impact assessment on the economy is related to the influence of government’s R&D investment such as national economic growth, employment etc. We also analyzed the spillover effect by industry according to R&D investment. Third, The social impact assessment is to analyze how R&D investment has impacted technology-based social change. This study is a very difficult attempt. However, we analyzed from the point of view of the consumer considering all social change areas as much as possible. The results of the study are summarized as follows. First, the study of economic impact evaluation shows the effect of R&D investment and it can be used as a basis to improve the efficiency and goal of R&D investment in future sectors such as employment, economic growth and investment. Second, through research on social impact assessment, government R&D investment has focused on specific areas in terms of improving the quality of life and social development of people, and confirmed that most social sectors are neglected. In addition, we proposed policy priorities for specific social change indicators and social sectors and proposed long-term R&D investment strategies. Finally, this study is expected to contribute to the establishment of future strategy of private enterprise through the measurement of social change index, the social influence of private research and development, and the influence of technology shock from abroad.

DNA 분석법에 의한 한우고기 판별

오홍록,이창수,상병찬,송광택 충남대학교 농업과학연구소 2006 농업과학연구 Vol.33 No.1

This study was deal with the development of breed-specific DNA marker which is able to identify Hanwoo and European cattle breeds(Non-Hanwoo) meat. Genetic differentiation between Korean cattle(Hanwoo) and European cattle breeds was examined by Random Amplified Polymorphic DNA(RAPD) analysis. The RAPD patterns were identical among Non-Hanwoo, such as Holstein, Hereford. Aberdeen Angus. Brown Swiss. Limousin or Simmental. but the above pattern was different from that of Hanwoo. All bands detected in the Hanwoo samples were observed in Non-Hanwoo cattle samples, but one of the common bands found in samples was not detected in the Hanwoo samples. The band(1.4kb) may be useful as a marker for identifying a meat of Hanwoo from imported cattle meat. Actually, the detection of the DNA marker was tested by DNA analysis with 929 samples which were prepared from bloods of 673 Hanwoo cattles and 141 Holstein cattles, from 115 imported cattle meats. The DNA marker was absent in 644 of 673 Hanwoo cattles (96%) but present in 245 of 256 Non-Hanwoo cattles (95%). These results show that the DNA marker is effective to characterize Hanwoo and Non-Hanwoo meat by its detection. This DNA marker, however, was not useful in detecting unwanted crossbreeding between two cattle breeds, because the band pattern in hybrid cattle shows one of two band patterns in Hanwoo and Non-Hanwoo.

GPS 測量에 의한 實用測地點의 活用에 관한 硏究

오창수,김원택 광주대학교 산업기술연구소 1995 産業技術硏究 Vol.5 No.-

본 연구는 GPS측량에 의한 실용측지점 활용의 타당성에 관한 논문으로 위성측량의 효율적인 자료처리를 위해 WGS-84 data를 우리나라 경위도 좌표계로 변환시킨 자료와 현재 사용하고 있는 광주광역시 일원의 기존 삼각점 및 도근점 10개를 선택하여 GPS성과와 기존성과를 비교 분석하여 신뢰성을 검증하고저 하였다. This study is concerned about the application of geodetic point by GPS surveying. This study is verified by comparison between data obtained by GPS satellite and study-site data which is used up to the present, ten points in Kwang-Ju are observed by GPS. They consist of three points of traingular coordinates of the Ministry of Construction, and convert by WGS 84 ellipsoids coordinate transformation system and study-site data used up tp the present are converted by Bessel coordinate transformation system.

일차적 비확공성 골수강 고정술로 치료한 제3형 개방성 경골 골절

오창욱,경희수,김도헌,박일형,김풍택,인주철,우연기,이정엽 대한골절학회 2004 대한골절학회지 Vol.17 No.2

연장 가골에 골 이식 대체물 투여가 골 경화에 미치는 영향 : 가토 경골에서의 방사선 및 골 밀도의 변화 Changes of Radiography & Bone Mineral Density in the Tibia of Rabbits

오창욱,김풍택,박병철,송해룡,박일형,백준호,박형진 경북대학교 병원 2003 경북대학교병원의학연구소논문집 Vol.7 No.1

목적 : 골 연장술 후 생기는 연장 가골에 황화 칼슘과 이종 이식골을 투여하여 골 경화 속도에 대한 영향을 알아보기 위한 실험이었다. 연구대상 및 방법 : 성장중인 뉴질랜드 화이트 토끼(2.0-2.5㎏)의 경골 간부에 골막을 보호하고, 절골술을 시행하고, 5일간의 휴지기후 외고정 장치를 이용하여 1주일 동안 7㎜가 연장될 때까지 하루 1㎜씩 2회의 리듬을 가지고 골 연장을 실시하였다. 제1 실험 군 7마리에는 연장이 끝난 직후 황화 칼슘(Osteoset^(ⓡ), Wright medical USA) 1정, 제 2 실험 군 7마리에는 이종 이식골의 일종인 Lubboc 5㎟을 각각 연장된 가골 부에 주입하고, 단순 연장한 대조군 7마리와 함께, 방사선 및 골 밀도비를 측정하고 추시하여, 골 경화의 진행속도를 비교하였다. 방사선 촬영은 전후면 및 측면사진을 1주 간격으로 촬영하였고, 골밀도 측정은 DEXA(dual energy X-ray absorptionmetry, Lunar^(ⓡ)) 장치를 2주일 간격으로 시행하였다. 결과 : 방사선 소견상, 제 1실험군의 연장가골의 완전 경화시간은 평균 14주, 제 2실험군은 154 주로 각각 대조군의 16.9주보다 단축되었으며, 골 밀도 비에서도, 두 실험군에서 최고치가 대조군의 값보다 높고, 최고치까지의 경과기간도 빨랐다. 결론 : 본 연구에서 연장 가골에 황화칼슘 및 이종 이식골의 투여가 골 경화의 기간을 단축시킬 수 있고, 외고정 장치의 빠른 제거에 도움이 될 수 있음을 알았다. Purpose : This study was designed to know the effect of calcium-sulfate and xenograft on the distracted callus after lengthening. Materials & Methods : We had operation of subperiosteal osteotomy and external fixation on the tibial diaphysis of young New Zealand White rabbits(2.0-2.5㎏); after 5 days of latency period, 7㎜(1㎜/day, 2times/day) of tibial lengthening was reached in a week. At 1 week after lengthening, the 1st experimental group of 7 rabbits received a pellet of calcium sulfate(Osteoset, Wright medical, USA) in the distraction gap, and the 2nd experimental group of 7 rabbits received 5㎜ 2 of xenogrfat(Lubboc) in the distraction gap. But, the control group of 7 rabbits did not receive any of above materials. We compared three groups with the changes of radiographic findings at every week and bone mineral ratio(DEXA) at every two weeks. Results : The time to complete consolidation of distraction callus of both experimental group(calcium sulfate;14 weeks, xenograft; 15.4 weeks) was shorter than that of control group(16.9 weeks) in radiographic findings. Maximum value of bone mineral ratio of distraction callus was higher and the time to reach the highest value was also shortened in the both experimental group compared to control group. Conclusion : By use of bone substitutes as like calcium sulfate or xenograft in the distraction callus with external fixator, it may be possible to shorten the consolidation period and the fixator-wearing period.

웹 기반 건설 하도급 대금지불 프로세스 모델

노준오,이현종,구교진,현창택 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1

The purpose of this study is to improve the subcontract payment process in domestic Construction industry. This study researches the previous documents and payment processes of construction company so that improves subcontract payment process. Recently, subcontract increase with time in domestic construction industry. But many subcontract companies have difficulty in financing problems because of unreasonable practice. Requesting a payment, contractor and subcontractor make out a payment so their time and effort necessarily were spent. Therefore unnecessary things are removed in subcontract payment process so that settle a reasonable subcontract payment process.

재발성 가와사끼병의 임상양상과 검사소견

유승택,최은정,이창우,오연균,박승택,윤향석 圓光大學校 醫科學硏究所 2003 圓光醫科學 Vol.18 No.2