• Tribology and Lubricants
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• 제25권2호
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• pp.86-95
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• 2009

Adhesion tests were carried out in order to investigate the effect of temperature on the adhesion behavior between a PMMA film and a fused silica lens in the micro scale. For the tests, a microtribometer system was specially designed and constructed. The pull-off forces on the PMMA film were measured under atmospheric condition as the temperature of the PMMA film was increased from 300 K to 443 K and decreased to 300 K. The contact area between the PMMA film and the lens was observed during the test. The adhesion behavior was changed with the change of the PMMA surface state as the temperature increased. In glassy state below 363 K, the pull-off force did not change with the increase of temperature. In rubbery state from 383 K to 413 K, the pull-off force increased greatly as the temperature increased. In addition, the area of contact was enlarged. In viscous state above 423 K, the fingering instability was observed in the area of contact when the PMMA film contacted with the lens. It was also found that the adhesion behavior can be varied with the thermal history of the PMMA film. The residual solvent in the PMMA film could emerge to the PMMA surface due to the heating and reduced the pull-off force.

• Archives of Reconstructive Microsurgery
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• 제23권2호
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• pp.93-96
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• 2014

The microscope is a surgical instrument with wide use in plastic surgeries more often than other departments due to the high rate of microscopic surgeries. Unfortunately, because the microscope is used mainly for digital replantations and free flaps, the utilization rate is low compared to the price and usability of the microscope itself. From September 2013 to March 2014, a foreign body which was untraceable with radiology in a patient who desired surgical exploration (one case), and a foreign body which was detected but was smaller than 3 mm (two cases) were removed using the microscope. All foreign bodies, which were fish bone, thin metals, or wooden objects, matching the history of the patients, were completely removed without damage. There were no complications and patient satisfaction was high through follow-up. We have described the microscope as the last and optimal examination tool in removal of micro foreign bodies. A simple change of thought, so that the microscope can be used as a second diagnostic tool will decrease complications by foreign bodies.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.67-70
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• 2004

An investigation was performed to study the impact damage of the laminated composite plates caused by a low- velocity foreign object with multi-scale modeling based on the concepts of Direct Numerical Simulation (DNS)[4]. In the micro-scale part, we discretize the composite plates through separate modeling of fiber and matrix for the local microscopic analysis. A micro-scalemodel was developed for predicting the initiation of the damage and the extent of the final damage as a function of material properties, laminate configuration and the impactor's mass, etc. Anda macro-scale model was developed for description of global dynamic behavior. The connection betweenmicroscopic and macroscopic is implemented by the tied interface constraints of LS-DYNA contact card. A transient dynamic finite element analysis was adopted for calculating the contact force history and the stresses and strains inside the composites during impact resulting from a point-nose impactor. The low-velocity impact events such as contact force, deformation, etc. are simulated in the macroscopic sense and the impact damages, fiber-breakage, matrix cracking and delamination etc. are examined in the microscopic sense.

• Journal of Ecology and Environment
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• 제29권2호
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• pp.175-183
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• 2006

The discovery of deep-sea hydrothermal vents and their ecosystems is a monumental landmark in the history of Ocean Sciences. Deep-sea hydrothermal vents are scattered along the global mid-ocean ridges and back-arc basins. Under sea volcanic phenomena related to underlying magma activities along mid-ocean ridges generate extreme habitats for highly specialized communities of animals. Multidisciplinary research efforts during past three decades since the first discovery of hydrothermal vents along the Galapagos Rift in 1977 revealed fundamental components of physiology, ecology, and evolution of specialized vent communities of micro and macro fauna. Heterogeneous regional geological settings and tectonic plate history have been considered as important geophysical and evolutionary factors for current patterns of taxonomic composition and distribution of vent faunas among venting sites in the World Ocean basins. It was found that these communities are based on primary production of chemosynthetic bacteria which directly utilize reduced compounds, mostly $H_2S$ and $CH_4$, mixed in vent fluids. Symbioses between these bacteria and their hosts, vent invertebrates, are foundation of the vent ecosystem. Gene flow and population genetic studies in parallel with larval biology began to unveil hidden dispersal barrier under deep sea as well as various dispersal characteristics cross taxa. Comparative molecular phylogenetics of vent animals revealed that vent faunas are closely related to those of cold-water seeps in general. In perspective additional interesting discoveries are anticipated particularly with further refined and expanded studies aided by new instrumental technologies.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제22권4호
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• pp.400-406
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• 2019

We report a 12-month-old female infant who had a history of neonatal sepsis with liver micro-abscesses that resolved with intravenous antibiotics during neonatal period. During her neonatal admission period, no umbilical vein catheter was inserted. Also, she did not undergo any abdominal surgeries or had a postnatal history of necrotizing enterocolitis. However, the child developed upper gastrointestinal bleeding in form of hematemesis and melena secondary to esophageal varices at the age of 12 months with an extra-hepatic portal vein obstruction with cavernous transformation and portal hypertension subsequently. The child underwent a successful endoscopic injection sclerotherapy. She is now 20-month-old and has portal hypertension but otherwise asymptomatic. We are proposing the possibility of a delayed-onset portal hypertension as a complication of liver abscess and neonatal sepsis.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.936-937
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• 2008

As a micro computer or micro processor technology has been advanced, the essential part which consists of electric power system has been changed into intelligent electronic device(IED), that is one kind of embedded system. There are already many parts changed into digital from analog in control and maintenance devices of electric system. These trends make advanced and novel concepts of devices and systems, that we couldn't even imagine in the analog circumstances. Now, the rate's of change is comparatively slower than IT field that is mainly represented by mobile communication, but that is a big change in the history of electric industries. Some people in those field called it Power-IT, and there have been many kinds of researches. Accelerated systems to go digital, users always and continuously demand more convenient, practical, and new functions. So, a lot of electric system manufactures have had tasks realizing many kinds of functions in an electronic device. According to the high-end technologies in semi-conductor and micro-computer field, manufactures can fully satisfy almost all of customer's needs, but there are other kinds of problems, such as large amount of program code, increasing complexity in proportion with program amount, and the hardness of maintenance and revision of the program. So nowadays, the necessity of embedded OS was emerged as a solution, and many researchers and manufactures have concentrated on studies related to embedded OS and its application.

• 한국광물학회:학술대회논문집
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• 한국암석학회.한국광물학회 2002년도 공동학술발표회 한국암석학회 창립10주년 기념 국제학술발표회
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• pp.1-3
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• 2002

The eastward extension of the suture zone between the Sino-Korea and Yangtze cratons in the Korean Peninsula and Japanese islands remains debatable (Hiroi, 1981; Cluzel et al., 1991; Yin and Nie, 1993; Sohma and Kunugiza, 1993; Isozaki, 1997; Arakawa et at., 2000), and is related to our understanding of the continent-continent collision orogeny. The collision orogeny varies in tectono-metamorphic processes and the timing differs from place to place, as exemplified by the absence of coesite and micro-diamond in the Korean Peninsula and Japanese islands, because it is a long-lived process of more than several tens of million years from subduction to exhumation in the Wilson cycle, and because the suture zone extends more than several thousand kilometers with a curved shape from the Qinling area of China to the Hida highland area of Japan. Hiroi (1981) is the first paper to correlate the Unazuki metamorphic rocks of the Hida metamorphic belt in Japan with the Ogcheon belt in the Korean Peninsula based on the presence of 240 Ma medium P/T metamorphic rocks in both belts, but there is a lack of recent studies on this correlation. To resolve the correlationship, there are two approaches: 1) petrological studies characterizing the origin and P-T history of rocks and 2) in-situ micro-dating of fine-grained, zoned minerals of zircon, monazite, uraninite and thorite using the EPMA (U-Th-Pb chemical dating or CHIME depending on calibration method) and the SHRIMP (Sensitive High-resolution ion Microprobe) to decipher the timing of geological events. As a first step of these approaches, micro-dating was undertaken to rocks of the Hida metamorphic belt and its Mesozoic cover (Tetori Group) in the Hida highland area, central Japan.

• Design & Manufacturing
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• 제2권1호
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• pp.33-38
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• 2008

As consumer in optics, electronics, aerospace and electronics industry grow, the demand for ultra precision aspherical surface lens increases higher. Precision turning with single-diamond tools has a long history of development for fabrication of optical quality surfaces since the advent of aerostatic rotary spindles and precise linear motion guide ways. To enhance the precision and productivity of ultra precision aspherical surface micro lens, the following specification of ultra precision grinding system is required: the highest rotational speed of the grinder is 100,000rpm and its turning accuracy is $0.1{\mu}m$, positioning accuracy is $0.1{\mu}m$. The development process of the grinding system for the ultra precision aspherical surface micro lens for optoelectronics industry is introduced. In the work reported in this paper, an intelligent grinding system for ultra precision aspherical surface machining was designed by considering the factors affecting the surface roughness and profiles accuracy. An aerostatic form was adopted to build the spindle of the workpiece and the spindle of grinder and ultra precision LM guide way was adopted in this system. And this paper deals with mirror grinding of an aspheric surface micro lens by resin bonded diamond wheel and spherical lens of BK7. It results was that a form accuracy of $0.6{\mu}m$ P-V and a surface roughness of $0.006{\mu}m$ Rmax.

• Genomics & Informatics
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• 제16권4호
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• pp.19.1-19.11
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• 2018

MicroRNAs (miRNAs), small non-coding RNAs, have been implicated in various diseases and cellular functions as microregulators of gene expression. Although the history of miRNA investigation in autoimmune $Sj{\ddot{o}}gren^{\prime}s$ syndrome (SjS) is fairly short, a substantial amount of data has already been accumulated. These findings clearly indicate potential clinical implications of miRNAs, such as autoantigen expression and autoantibody production, viral miRNAs regulating the calcium signaling pathway, and aberrant immune cell regulation and cytokine production. Research endeavors in the field are currently underway to select disease-specific diagnostic and prognostic biomarkers by utilizing different types of tissues or biological specimens of SjS patients. Various techniques for miRNA analysis with different stringencies have been applied, with the most recent one being next-generation sequencing. This review compiles and highlights differentially-expressed miRNAs in various samples collected from SjS patients and their potential implications in the pathogenesis of SjS. To facilitate the development of miRNA-targeted personalized therapy in the future, we urge more follow-up studies that confirm these findings and elucidate the immunopathological roles of differentially-expressed miRNAs. Furthermore, improved diagnostic criteria for the disease itself will minimize sampling errors in patient recruitment, preventing the generation of inconsistent data.

• Parasites, Hosts and Diseases
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• 제21권2호
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• pp.246-256
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• 1983

폐흡충증의 유행정도를 측정하는 데 사용하여 온 피내반응과 충란검사가 각각 특이도와 민감도에 문제를 갖고 있어 주민 중 현증 환자를 적절히 찾았다고 하기가 어렵게 되어가고 있다. 이러한 점을 개선하는 방법으로 폐흡충 특이 IgG항체를 검사함으로써 항체양성자의 수를 현증 환자의 수로 하는 방법을 폐흡충증 역학조사에 응용하고자 하였다. 이 연구에서는 특이항체를 면역효소진단법으로 측정하였을 때 그 효용성을 평가하고자 하였다. 전라남도 해남군 북평면과 북일면의 6개 국민학교, 2개 중학교, 1개 고등학교 학생과 2개 부락 주민 등 모두 4,285명을 우선 피내 반응으로 검사하고 폐흡충 피내반응 양성자에서 가래 검사를 한번 실시하였고 혈청을 채취하여 면역효소진단법으로 폐흡충 특이 IgG항체를 측정하였다. 그 결과를 요약하면 다음과 같다. 1. 총 대상자 4,285명 중 폐홉충 피내반응 양성자는 244명 (5.7%)이었고, 피내반응 양성자 중 충란 양성자는 7명 (4.2%), 면역효소진단법에 의한 특이 IgG항체 양성자는 40명 (16.7%)이었다. 전체 조사 대상자에 대한 충란 양성자의 비율은 0. 16%, 특이 IgG항체 양성자는 0.93%에 해당하였다. 2. 폐흡충 특이 IgG항체 양성자는 충란 양성자에서는 100%, 폐흡충 피내 반응은 양성이나 충란검사 음성자에서는 14.2%에서 나타났으나, 간흡충 피내반응 양성자 또는 피내반응 음성 자에서는 나타나지 않았다. 3. 폐흡충 특이 IgG항체 양성자는 피내반응 구진의 크기 9mrn이하에서는 없었고, 10mm에서는 5.5%, 11∼12mm에서는 26.1% 및 18.2%, 13mm이상에서는 평균 42.4%에서 양성이었다. 4. 특이항체 양성자 31명을 임상적으로 조사한 바 검사소건(흉부 X-선, 충란검사 및 호산구 비율)에서 폐흡충증에 합치하는 이상소견이 24례에서 나타나 현증 폐홉충증 환자로 생각할 수 있었고, 나머지 7례중 3례는 폐흡충증의 과거력이나 쳔증 증상을 갖고 있었으며 4례에서는 특이항체 양성소견 이외에는 어느 검사로도 폐흡충증임을 증명할 수가 없었다. 5. 폐홉충 특이 IgG항체 양성자 수의 피내반응 양성자 수에 대한 비율은 연령별로 7∼9세에서는 16.6%, 10∼14세에서 25.4%, 15w18세 군에서는 18.3%이었고 20세 이상에서는 10.0%로 떨어지고 있었다. 6. 체홉충 특이 IgG항체 양성자는 북평면의 산골 마을에서 주로 나타나고 있었다. 이상과 같은 결과에서 면역효소 진단법에 의하여 폐흡충 특이 IgG항체 양성자를 조사함으로써 어느 지역의 폐흡충중 현증 환자를 피내 반응이나 충란 검사보다도 더 사실에 가깝게 측정할 수 있다고 생각하였다. (이 연구를 수행하는데 현지조사를 직접 간접으로 도와 주신 해남군 보건소 민 경 소장님과 김용팔 주사, 북평면 면사무소 직원여러분과 해남군 교육청, 각급학교 교직원 여러분께 감사드립니다. 환자의 흉부 X-선 사진을 판독하여 주신 중앙의대 부속 성심병원 방사선과 과장 정전상 부교수께 도 감사드립니다. )