• 대한화장품학회지
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• 제45권1호
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• pp.69-75
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• 2019

우리나라 화장품의 살균 보존제 성분은 포지티브 리스트로 관리되고 있다. 포지티브 리스트는 적절한 정량분석법이 필요하지만 아직 분석법 개발이 미비한 상황이다. 본 실험에서는 가스크로마토그래피와 불꽃이온화검출기(GC/FID)를 이용하여 살균 보존제 성분 14종을 동시분석 하는 방법을 개발하였다. 분석법의 validation 결과 특이성을 확인하였고, 검량선의 직선성은 dehydroacetic acid (0.9891)를 제외한 14종에서 상관계수가 0.9997 이상으로 양호하였다. 검출한계(LOD)와 검량한계(LOQ)는 각각 0.0001 mg/mL ~ 0.0039 mg/mL와 0.0003 mg/mL ~ 0.0118 mg/mL로 나타났으나, dehydroacetic acid는 각각 0.0204 mg/mL, 0.0617 mg/mL로 나타났다. 반복성은 1.0% 이하로 나왔으나 dehydroacetic acid는 7.1%로 나왔다. 회수률은 96.9% ~ 109.2% 나타났다. 본 실험방법으로 유통 중인 화장품 50건을 검사한 결과 화장품에 주로 사용되는 살균 보존제는 chlorophene, phenoxyethanol, benzyl alcohol, parabens 이고, 모두 배합한도 이내로 검출되었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.273-273
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• 2013

Recently, Point-of-care (POC) testing microdevices enable to do the patient monitoring, drug screening, pathogen detection in the outside of hospital. Immunochromatographic strip (ICS) is one of the diagnostic technologies which are widely applied to POC detection. Relatively low cost, simplicity to use, easy interpretations of the diagnostic results and high stability under any circumstances are representative advantages of POC diagnosis. It would provide colorimetric results more conveniently, if the genetic analysis microsystem incorporates the ICS as a detector part. In this work, we develop a reverse transcriptase-polymerase chain reaction (RT-PCR) microfluidic device integrated with a ROSGENE strip for colorimetric influenza H1N1 virus detection. The integrated RT-PCR- ROSGENE device is consist of four functional units which are a pneumatic micropump for sample loading, 2 ${\mu}L$ volume RT-PCR chamber for target gene amplification, a resistance temperature detector (RTD) electrode for temperature control, and a ROSGENE strip for target gene detection. The device was fabricated by combining four layers: First wafer is for RTD microfabrication, the second wafer is for PCR chamber at the bottom and micropump channel on the top, the third is the monolithic PDMS, and the fourth is the manifold for micropump operation. The RT-PCR was performed with subtype specific forward and reverse primers which were labeled with Texas-red, serving as a fluorescent hapten. A biotin-dUTP was used to insert biotin moieties in the PCR amplicons, during the RT-PCR. The RT-PCR amplicons were loaded in the sample application area, and they were conjugated with Au NP-labeled hapten-antibody. The test band embedded with streptavidins captures the biotin labeled amplicons and we can see violet colorimetric signals if the target gene was amplified with the control line. The off-chip RT-PCR amplicons of the influenza H1N1 virus were analyzed with a ROSGENE strip in comparison with an agarose gel electrophoresis. The intensities of test line was proportional to the template quantity and the detection sensitivity of the strip was better than that of the agarose gel. The test band of the ROSGENE strip could be observed with only 10 copies of a RNA template by the naked eyes. For the on-chip RT-PCR-ROSGENE experiments, a RT-PCR cocktail was injected into the chamber from the inlet reservoir to the waste outlet by the micro-pump actuation. After filling without bubbles inside the chamber, a RT-PCR thermal cycling was executed for 2 hours with all the microvalves closed to isolate the PCR chamber. After thermal cycling, the RT-PCR product was delivered to the attached ROSGENE strip through the outlet reservoir. After dropping 40 ${\mu}L$ of an eluant buffer at the end of the strip, the violet test line was detected as a H1N1 virus indicator, while the negative experiment only revealed a control line and while the positive experiment a control and a test line was appeared.

• 한국환경보건학회지
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• 제47권5호
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• pp.384-397
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• 2021

Background: With volatile organic compounds (VOCs) containing aromatic and halogenated hydrocarbons such as benzene, toluene, and xylene that can adversely affect the respiratory and cardiovascular systems when a certain concentration is reached, it is important to accurately evaluate the source and the corresponding health risk effects. Objectives: The purpose of this study is to provide scientific evidence for the city of Seoul's VOC reduction measures by confirming the risk of each VOC emission source. Methods: In 2020, 56 VOCs were measured and analyzed at one-hour intervals using an online flame ionization detector system (GC-FID) at two measuring stations in Seoul (Gangseo: GS, Bukhansan: BHS). The dominant emission source was identified using the Positive Matrix Factorization (PMF) model, and health risk assessment was performed on the main components of VOCs related to the emission source. Results: Gasoline vapor and vehicle combustion gas are the main sources of emissions in GS, a residential area in the city center, and the main sources are solvent usage and aged VOCs in BHS, a greenbelt area. The risk index ranged from 0.01 to 0.02, which is lower than the standard of 1 for both GS and BHS, and was an acceptable level of 5.71×10^-7 to 2.58×10^-6 for carcinogenic risk. Conclusions: In order to reduce the level of carcinogenic risk to an acceptable safe level, it is necessary to improve and reduce the emission sources of vehicle combustion and solvent usage, and eco-car policies are judged to contribute to the reduction of combustion gas as well as providing a response to climate change.

• 한국컴퓨터정보학회논문지
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• 제10권6호
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• pp.9-16
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• 2005

최근 인터넷 이용자들이 급격하게 증가하고 있으며, 초보수준의 일반 네트워크 사용자들도 인터넷상의 공개된 해킹 도구들을 사용하여 고도의 기술을 요하는 침입이 가능하여 해킹 문제가 더욱 심각해지고 있다. 해커들이 침입하기 위하여 취약점을 알아내려고 의도하는 다양한 형태의 침입시도를 사전에 탐지하여 침입이 일어나는 것을 미리 방어할 수 있는 침입시도탐지가 적극적인 예방 차원에서 더욱 필요하다. 기존의 포트 스캔이나 네트워크 취약점 공격에 대응하기 위한 네트워크 기반의 비정상 침입시도 탐지 알고리즘은 침입시도함지에 있어 몇 가지 한계점을 갖고 있다. 기존 알고리즘은 Slow Scan, Coordinated Scan을 할 경우 탐지할 수 없다는 것이다. 따라서 침입시도 유형에 제한을 받지 않고 침입시도에 관한 다양한 형태의 비정상 접속을 효과적으로 탐지할 수 있는 새로운 개념의 알고리즘이 요구된다. 본 논문에서는 세션 패턴과 탐지 오류율을 규칙기반으로 하는 침입시도 탐지알고리즘(Session patterns & FCM Anomaly Detector : SFAD)을 제안한다.

• 한국화재소방학회논문지
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• 제19권2호
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• pp.75-80
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• 2005

적충형 PTC 서미스터의 특성연구를 위해 $(0.90Ba+0.05Sr+0.05Ca)TiO_3+0.01TiO_3+0.01SiO_2+0.0008MnO_2+0.0018Nb_2O_5$와 같은 실험조성식을 설정한 후 표면실장(SMD) 적층형 PTC 시편을 제작하였다. 그 결과 상온 비저항 값을 크게 낮출 수 있고 용도에 따라 전류용량을 크게 할 수 있었으나 적층화로 인해 peak 비저항이 크게 낮아지고 열용량이 커짐으로써 스위칭(switching)시간이 늦어지는 점을 확인하였다. 전압-전류 특성에서는 적층수가 증가할수록 초기 최대전류값이 증가하며 큐리점에 대응하여 저항값이 급격히 커지는 전이전압(전계)도 증가함을 보였다. 그러나 인가전압(전계)을 증가시킬 경우 peak 비저항값을 높일 수 있어 스위칭시간을 줄일 수 있다 이 소자는 화재감지기의 센서로 활용될 수 있다.

• Journal of the korean society of oceanography
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• 제36권4호
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• pp.101-108
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• 2001

Polybrominated diphenylether (PBDEs) congeners, 2,4,4'-TrBDE, 2,2',4,4'-TeBDE, 2,2',4,4',5-PeBDE, 2,2',4,4',5,5'-HXBDE, and 2,2',4,4',5,6-HxBDE, were measured in sediments from 52 stations in the southeastern coastal areas of Korea. Sediment samples were analyzed using gas chromatography coupled to mass spectrometer detector (GC/MSD) with positive electron impact (PEI) mode. New analytical methodology for PBDEs by the isotope dilution method was established using a multi-layer silica gel column chromatography. Total PBDEs levels in sediments for Pohang coast ranged from 1,1 to 33.8 ng/g dry weight (mean 5.3 ng/g dry), from 1.6 to 36.4 ng/g dry weight (mean 5.7 ng/g dry) for Ulsan coast, from 0.8 to 20.3 ng/g dry weight (mean 4.9 ng/g dry) for Busan coast, and from 0.8 to 10.3 ng/g dry weight (mean 4.4 ng/g dry) for Jinhae Bay. PBDEs contamination in surface sediments from Korean southeastern coasts was relatively moderate in comparison to that of other marine environment in the world. The predominant PBDE congeners were 2,2',4,4'-TeBDE and 2,2',4,4',5-PeBDE.

• Journal of Pharmaceutical Investigation
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• 제41권5호
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• pp.309-315
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• 2011

A sensitive and specific liquid chromatographic method coupled with tandem mass spectrometry (LC-MS/MS) was developed for the analysis of ambroxol (active moiety of acebrophylline). After acetonitrile precipitation of proteins from plasma samples, ambroxol and the domperidone (internal standard, IS) were eluted on a C18 column. The isocratic mobile phase was consisted of 10 mM ammonium acetate and methanol (10 : 90, v/v), with flow rate at 0.2 mL/min. A tandem mass spectrometer, as detector, was used for quantitative analysis in positive mode by a multiple reaction monitoring mode to monitor the m/z 379.2${\rightarrow}$264.0 and the m/z 426.2${\rightarrow}$175.1 transitions for ambroxol and the IS, respectively. Twenty four healthy Korean male subjects received two capsules (100 mg ${\times}$ 2) of either the test or the reference formulation of acebrophylline HCl in a 2 ${\times}$ 2 crossover study, this was followed by a 1week washout period between either formulation. $AUC_{0-t}$ (the area under the plasma concentration-time curve) was calculated by the linear trapezoidal rule. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. The 90% confidence intervals for the log transformed data were acceptable range of log 0.8 to log 1.25 (e.g., log 0.8964 - log 0.9910 for $AUC_{0-t}$ log 0.8690 - log 1.0750 for $C_{max}$). The major parameters, $AUC_{0-t}$ and $C_{max}$ met the criteria of Korea Food and Drug Administration for bioequivalence indicating that Acephyll$^{(R)}$ capsule (test) is bioequivalent to Surfolase$^{(R)}$ capsule (reference).

• Asian Pacific Journal of Cancer Prevention
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• 제13권12호
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• pp.6269-6272
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• 2012

We conducted a case-control study to determine the association between several potential SNPs of excision repair cross complementing group 5 (XPG) and gastric cancer susceptibility, and roles of XPG polymorphisms in combination with H.pylori infection in determining risk of gastric cancer. In our study, we collected 337 newly diagnosed gastric cancer cases and 347 health controls. Three SNPs of XPG, rs2296147T>C, rs2094258C>T and rs873601G>A, were genotyped using the Taqman real-time PCR method with a 7900 HT sequence detector system. H. pylori infection was diagnosed by ELISA. By multivariate logistic regression analysis, the rs2296147 CC genotype was associated with a decreased risk of gastric cancer (OR=0.52, 95% CI=0.27-0.97), and rs2094258 TT was associated with elevated risk (OR=2.13, 95% CI=1.22-3.35). Positive H.pylori individuals with rs2094258 TT genotypes demonstrated increased risk of gastric cancer (OR=2.13, 95% CI=1.22-3.35), while rs2296147 CC was associated with lower risk among patients with negative H.pylori (OR=0.45, 95%CI=0.22-0.89). Our findings suggested that XPG polymorphisms might contribute to risk of gastric cancer among Chinese populations, but the effect needs to be further validated by larger sample size studies.

• 한국ITS학회 논문지
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• 제11권1호
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• pp.1-12
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• 2012

국내에 교통량의 변동을 고려하기 위하여 영상검지기를 이용한 반감응 신호제어시스템의 설치가 증가하고 있지만 그러한 반감응 신호제어시스템의 도입효과 및 성능을 평가하기 위한 절차 및 방법론은 아직까지 수립되어 있지 않다. 이에 본 연구에서는 효과분석 및 성능평가를 위한 방법론을 수립하였다. 개발된 방법론에서는 반감응 신호제어시스템의 특성을 고려하여 교통환경 개선 파악에 유용한 효과척도와 조사항목이 우선 설정되었고, 현장조사와 평가를 통해 시스템의 성능 및 도입에 따른 교통환경의 개선효과를 파악할 수 있는 방법을 제시하고 있다. 또한 본 연구에서는 개발된 방법론을 파주시 반감응 신호제어시스템에 대해서 사례 분석을 실시하였다. 단일교차로와 간선축으로 구분된 사례분석에서 교통량, 통행속도 항목과 신호효율측면의 현시이용효율, 연동효율 등 선정된 효과척도 분석결과 시스템 도입에 따라 일정수준의 개선효과가 있는 것으로 나타났다.

• Journal of Gastric Cancer
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• 제18권1호
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• pp.20-29
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• 2018

Purpose: Pre-operative lymph node (LN) size is a valuable parameter for determining treatment strategy for gastric cancer. However, a correlation between LN size and metastasis has not been established. Materials and Methods: Thirty-six LN-positive (LNP) and matched 36 LN-negative (LNN) patients were included, and pathology slides of the LNs of these patients were reviewed. All the LNs were measured along the long-axis (LA) and short-axis (SA), manually. Results: Average retrieved LNs were $37.3{\pm}19.8$ and $40.5{\pm}11.6$ in the LNN and LNP groups, respectively. In total 2,800 LNs, including 136 metastatic LNs (MLNs) and 2,664 non-metastatic LNs (nMLNs), were evaluated. Mean length was significantly more in MLNs along both, the LA and SA (MLN_LA vs. nMLN_LA: $4.97{\pm}3.84$ vs. $3.37{\pm}2.40mm$, MLN_SA vs. nMLN_SA: $3.86{\pm}3.19$ vs. $2.43{\pm}1.59mm$; P<0.001). However, 92.6% (126/136) and 95.6% (130/136) of MLNs were <10 mm along the LA and SA, respectively. In addition, only 22.2% of the LNP group exhibited an MLN as the largest LN. Conclusions: Pre-operative multi-detector computed tomography has limited ability in estimating the presence of metastasis in LNs because most MLNs are less than 10 mm, and only a small proportion of the LNP group exhibits an MLN as the largest MLN.