• 한국자동차공학회논문집
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• 제18권5호
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• pp.85-90
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• 2010

As the environmental regulation of vehicle emission is strengthened, investigations for $NO_x$ and PM reduction strategies are popularly conducted. Two current available technologies for continuous $NO_x$ reduction onboard diesel vehicles are Selective Catalytic Reduction (SCR) using aqueous urea and lean $NO_x$ trap (LNT) catalysts. The experiments were conducted to investigate the $NO_x$ reduction performance of SCR system which can control the ratio of $NO/NO_2$, temperature and SV(space velocity), and the model gas was used which is similar to a diesel exhaust gas. The maximum reduction efficiency is indicated when the $NO:NO_2$ ratio is 1:1 and the SV is 30,000 $h^{-1}$ in $300^{\circ}C$. Generally, ammonia slip from SCR reactors are rooted to incomplete conversion of $NH_3$ over the SCR. In this research, slip was occurred in 6cases (except low SV and $NO:NO_2$ ratio is 1:1) after SCR. Among 6 case of slip occurrence, the maximum conversion efficiency is observed when SV is 60,000 $h^{-1}$ in $400^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• 제12권4호
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• pp.598-602
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• 2002

Damage to cells exposed to radiation is primarily attributed to direct effects on the structure of cellular DNA. Radiation-induced damage of pBluescript SK plasmid DNA and Escherichia coli $DH5\alpha$ were examined in the presence of various branched oligosaccharides, polysaccharides, and/or 8-MOP (8-methoxypsoralen). Branched oligosaccharides efficiently protected DNA and cells exposed to ultrasoft X-ray and UV irradiation. In the presence of 0.2% (w/v) branched oligosaccharides and polysaccharides, DNA can be protected from damage due to W and ultrasoft X-ray by a factor of 1.3-2.1 fo1d and 3.2-8.3 fold, respectively. The protective effect of cells exposed to UV or ultrasoft X-ray was also observed by branched oligosaccharides. The combination of MOP, a photoreagent, with carbohydrates increased the protective effects for DNA and cells, compared with that of a single use of MOP or carbohydrate alone.

• 한국임상수의학회지
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• 제29권6호
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• pp.506-508
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• 2012

5년령 중성화하지 않은 암컷 포메라니언이 닭뼈를 삼킨 후 구토를 주증으로 내원하였다. 내시경을 통한 식도이물 제거 후 식도에 작은 천공을 확인하였다. 수술적 치료 대신 비수술적 관리를 통하여 치료하였고 3주 후 내시경을 통한 재검사 결과 천공부위의 완전한 폐쇄를 확인하였다. 본 연구는 식도 이물에 의한 식도 천공을 비수술적 관리를 통해 성공적으로 치료한 증례에 대한 보고이다.

• Bulletin of the Korean Chemical Society
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• 제32권6호
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• pp.2032-2038
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• 2011

Matrix metalloproteinases (MMPs), a family of zinc-containing endopeptidases, participate in many normal processes such as embryonic development and wound repair, and in many pathological situations such as cancer, atherosclerosis, and arthritis. Peptidomimetic MMP inhibitors were designed and synthesized with N-formylhydroxylamine (retrohydroxamate) as a zinc-binding group and various side chains on the ${\alpha}$, P1', and P2' positions. Using in vitro MMP assays with purified MMPs (MMP-1, MMP-2, MMP-3, MMP-9, and MMP-14) and fluorogenic peptide substrates, it was found that compounds 2d and 2g selectively inhibit gelatinases (MMP-2 and MMP-9) and interstitial collagenase (MMP-1). They also inhibited the chemo-invasion of fibrosarcoma HT-1080 cells and tube formation of human umbilical vascular endothelial cells in a dose-dependent manner. Our results suggest that retrohydroxamate-based MMP inhibitors, especially compounds 2d and 2g, have the potential to be used as therapeutic drugs for cancer and other MMP-related diseases.

• Advances in pediatric surgery
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• 제10권1호
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• pp.31-34
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• 2004

The laparoscopic splenectomy (LS) became popular over the last 10 years. The advantage of LS over open splenectomy (OS) includes short hospital stay, improved cosmesis, less development of postoperative intestinal ileus, and less analgesics required. The purpose of this study is to evaluate the outcome of LS at Asan Medical Center from January 1999 to January 2003. The records of 14 consequent children who underwent splenectomy were reviewed retrospectively. Patients characteristics, morbidity, mortality, operative time, blood loss, and hospital stay were analyzed., Seven patients age 5 to 15 years underwent LS under the indications: idiopathic thrombocytic purpura (ITP, n=3), hereditary spherocytosis (n=3), and myelodysplastic syndrome (n=l). Seven patients, age 7 to 16 years, underwent OS during the same period for ITP (n=7). Median operative time was 120 mInutes (80 to 170 mins.) in OS, and 270 minutes (110 to 480 mins,) in LS (p<0.05). Median length of hospital stay was 6 days (3 to 8) in OS, and 4 days (3 to 6) in LS (p>0.05). Median splenic length was 12.0cm (9.2 to 18.0) in OS, 14.0 cm (10.0 to 19.5) (p>0.05). Accessory spleens were identified in 3 of 7 LS and 1 of 7 OS cases. In the LS group, there was no conversion to open surgery. Two patients in LS required blood transfusion postoperatively. LS in children can be performed as effectively and safely as OS.

• 한국항해항만학회지
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• 제29권10호
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• pp.847-852
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• 2005

본 연구에서는 선박의 항해 안전성과 정박 중인 선박의 계류 안전성 평가에 기초가 되는 선체운동 평가를 위한 다목적 계측시스템을 개발하는데 있다. 다목적 계측시스템은 선박에 탑재되어 외력에 의해 발생하는 동적 동요를 계측 및 분석하기 위해 상하, 좌우, 전후방향의 가속도량을 측정하는 3축 가속도 계측기를 포함하여, 방위 센서, 2축 경사계 및 초음파 변위계로 구성하였다. 선박의 항해 및 계류 안전성을 종합적으로 평가하기 위해서는 특정 센서를 이용, 선체운동을 실시간으로 측정하여 내항성능 평가 시스템과 항해 또는 정박 중인 선박의 상태에 관한 선박 데이터베이스 시스템을 이용하여 평가한다. 개발된 다목적 계측시스템은 해상에서의 전복사고 분석, 선박 출입항 통제, 부두에서의 하역작업 통제, 조선소에서의 내항성능 및 안전설계에 있어서도 적용이 가능하리라 본다.

• 한국산학기술학회논문지
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• 제13권9호
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• pp.4334-4340
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• 2012

본 연구에서는 미세 액적을 발생시키는 액적 발생 장치를 개발 제작하고 이에 대한 성능 평가를 실시하였다. 액적 발생 장치는 spray-evaporation method를 기초로 제작하였으며, 0.3mm, 0.5mm의 오리피스를 사용하였다. 압축 공기 공급 압력을 1bar에서 4bar로 증가시키면서 공급 압력에 따른 발생되는 액적 크기의 미세 정도를 비교하였다. 또한 SMPS(Scanning Mobility Particle Sizer)와 OPC(Optical Particle Counter)를 이용하여 서로 다른 오리피스를 장착한 액적 발생 장치에서 발생되는 액적의 크기 분포를 측정하였다. 연구 결과, 0.3mm 오리피스를 장착한 장치에서 발생되는 액적은 $0.3{\mu}m$ 인근의 크기가 가장 많았으며, 미립화되는 입자는 매우 안정적이었다. 또한 0.5mm 오리피스를 장착한 장치가 0.3mm 오리피스를 장착한 장치에 비해 발생되는 액적의 크기가 큰 것으로 나타났다. 이러한 액적 발생 장치는 입자의 미세한 응집 현상이 나타나는데, 이것은 내부 액체가 미세한 액적으로 미립화되어 분사되기 때문인 것으로 사료된다. 본 연구에서 제작한 액적 발생 장치는 미세 입자를 미립화하기 위한 에어로졸 발생 장치로 사용 가능한 것으로 판단된다.

• 한국염색가공학회지
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• 제27권2호
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• pp.149-154
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• 2015

To investigate the biodegradation of the cellulose powder(CP) derived from Styela clava tunics(SCT), some physico-chemical properties and biodegradability of SCT-CP were measured after the incubation for 45 days. The particles size of SCT-CP prepared with washing, bleaching, drying, and grinding processes was $150-400{\mu}m$ although most of particles (70%) was more than $400{\mu}m$. The cellulose structures of SCT-CP detected using the X-ray diffraction and DSC analysis was very similar with that of wood pulp powder(WP-CP). The glass transition temperature was not detected in both samples. Furthermore, more than 90% of the SCT-CP was degraded, whereas only over 70% of the WP-CP was degraded after the incubation for 45 days. Therefore, these results suggest the possibility that SCT-CP is particularly applicable to prepare medical fiber and film for disease treatment.

• Journal of Pharmaceutical Investigation
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• 제39권1호
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• pp.37-41
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• 2009

The purpose of this study was to compare the efficacy of Lorelin Depot $Injection^{(R)}$ (Dongkook Pharm. Co., LTD) with Lucrin Depot $Injection^{(R)}$ (Abbott) by measuring serum testosterone level in rats. Leuprorelin (leuprolide acetate), which is an active compound for the two formulations, is an LHRH analogue that is used for the treatment of a wide range of sex hormone-related disorders including advanced prostatic cancer, endometriosis and precocious puberty. Lorelin Depot $Injection^{(R)}$ is a micro-encapsulated formulation to suppress testosterone level by releasing leuprorelin continuously for four weeks with a single subcutaneous injection. The comparison study of the efficacy was performed during four weeks, and serum testosterone levels were monitored in the two formulations. The mean serum testosterone levels from the formulations were decreased to that of the castrate range (50 ng/dL or less) after three days after the initial depot injection, and the concentration were remained throughout four weeks' period. There were no significant differences in the $AUC_{0-3day}$ of testosterone and testosterone levels at 3, 7, 14, 21 and 28 days between the two formulations. These results indicate that the two formulations, Lorelin Depot $Injection^{(R)}$ and Lucrin Depot $Injection^{(R)}$, are bioequivalent in terms of the serum testosterone level in rats.

• 수산해양기술연구
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• 제45권3호
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• pp.157-164
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• 2009

Due to change of various marine environments according to seawater temperature rising, Japanese common squid(Todarodes pacificus), which was distributed in East Sea, was recently caught in Yellow Sea during a summer season from 2006. The fishery resources density research was carried out in Korea-China Provisional Water Zone using trawl fishing gear and acoustics in National Fisheries Research & Development Institute in Korea. This paper showed the analysis on the acoustical backscattering strength by two frequencies(38kHz, 120kHz) for Japanese common squid by acoustical scattering theoretical model based on size distribution for survey period, and estimate the density distribution for squid s integrated layer which was extracted from any scatterers distributed in water column using two frequency difference method which has been used to distinguish fish shoals or specific target scatterers from sound scattering layer which is composed of various zooplankton. Furthermore, the entire range of their density estimation was suggested using by Monte Carlo simulation under considering each uncertainty such as size distributions or swimming angle and so on in survey area.