• Asian Journal of Atmospheric Environment
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• 제6권1호
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• pp.53-66
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• 2012

A comparison of analytical approaches for Levoglucosan ($C_6H_{10}O_5$, commonly formed from the pyrolysis of carbohydrates such as cellulose) and used for a molecular marker in biomass burning is made between the four different analytical systems. 1) Spectrothermography technique as the evaluation of thermograms of carbon using Elemental Carbon & Organic Carbon Analyzer, 2) mass spectrometry technique using Gas Chromatography/mass spectrometer (GC/MS), 3) Aerosol Mass Spectrometer (AMS) for the identification of the particle size distribution and chemical composition, and 4) two dimensional Gas Chromatography with Time of Flight mass spectrometry (GC${\times}$GC-TOFMS) for defining the signature of Levoglucosan in terms of chemical analytical process. First, a Spectrothermography, which is defined as the graphical representation of the carbon, can be measured as a function of temperature during the thermal separation process and spectrothermographic analysis. GC/MS can detect mass fragment ions of Levoglucosan characterized by its base peak at m/z 60, 73 in mass fragment-grams by methylation and m/z 217, 204 by trimethylsilylderivatives (TMS-derivatives). AMS can be used to analyze the base peak at m/z 60.021, 73.029 in mass fragment-grams with a multiple-peak Gaussian curve fit algorithm. In the analysis of TMS derivatives by GC${\times}$GC-TOFMS, it can detect m/z 73 as the base ion for the identification of Levoglucosan. It can also observe m/z 217 and 204 with existence of m/z 333. Although the ratios of m/z 217 and m/z 204 to the base ion (m/z 73) in the mass spectrum of GC${\times}$GC-TOFMS lower than those of GC/MS, Levoglucosan can be separated and characterized from D (-) +Ribose in the mixture of sugar compounds. At last, the environmental significance of Levoglucosan will be discussed with respect to the health effect to offer important opportunities for clinical and potential epidemiological research for reducing incidence of cardiovascular and respiratory diseases.

• 한국대기환경학회지
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• 제33권2호
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• pp.124-138
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• 2017

Physico-chemical measurement of non-refractory submicron particles($NR-PM_1$) was conducted in Baengnyeong Island, Korea using Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) from 2012 to 2014. Organics and ammoniated sulfate were dominant species in $NR-PM_1$. The organics was found to have similar fractions(approximate 40%) of $NR-PM_1$ during the summer and winter, while the sulfate fractions of $NR-PM_1$ were calculated to be approximately 47% and 31% for the summer and winter, respectively, suggesting the possibility that particles provide non-acidic surfaces for condensation of nitric acid in the winter. The nitrate fractions of approximate 4% and 20% of $NR-PM_1$ were observed in August (summer) and November (winter), respectively, resulting that the relatively low concentration of sulfate in $NR-PM_1$ provided a non-acidic surface for nitric acid condensation and formation of particulate ammoniated nitrate is favored thermodynamically in winter. The new particle formation (NPF) event and particle growth rate were analyzed for each month in 2014 using Scanning Mobility Particle Sizer(SMPS). The Percent of NPF events was the highest in winter, but NPF event was not observed during summer due to relatively high temperature and frequent rainfall. The average particle growth rate was 3.5 nm/h and the highest particle growth rate was 5.5 nm/h in May. We observed the long-range transport of the anthropogenic sulfate from the East Asia during the intensive monitoring period of November between Qingdao and Baengnyeong Island in 2013. The relatively high concentrations of m/z 60 measured in HR-ToF-AMS was observed in May and June at Baengnyeong Island, suggesting the possibility of the influence of biomass burning from the East Asia to the Korean Peninsula.

• International Journal of Computer Science & Network Security
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• 제21권3호
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• pp.245-256
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• 2021

Poor logistical infrastructure and agri-food supply chain management leads to significant food waste in logistic system. The concept of the sustainable value added agri-food chains requires defined approach to the analysis of the existing situation, possible improving strategies and also assessment of these changes impact on further development. The purpose of research is to provide scientific substantiation of theoretical and methodological principles and develop practical recommendations for the improvement of the agri-food logistics distribution system. A case study methodology is used in this article. The research framework is based on 4 steps: Value Stream Mapping (VSM), Gap and Process Analysis, Validation and Improvement Areas Definition and Imitation Modelling. This paper presents the appropriateness of LEAN logistics tools using, in particular, Value Stream Mapping (VSM) for minimizing logistic losses and Simulation Modeling of possible logistics distribution system improvement results. The algorithm of VSM analysis of the agri-food supply chain, which involves its optimization by implementing the principles of sustainable development at each stage, is proposed. The methodical approach to the analysis of possible ways for optimizing the operation of the logistics system of the agri-food distribution is developed. It involves the application of Value Stream Mapping, i.e. designing of stream maps of the creation of the added value in the agri-food supply chain for the current and future state based on the minimization of logistic losses. Simulation modeling of the investment project on time optimization in the agri-food supply chain and economic effect of proposed improvements in logistics product distribution system functioning at the level of the investigated agricultural enterprise has been determined. Improvement of logistics planning and coordination of operations in the supply chain and the innovative pre-cooling system proposed to be introduced have a 3-year payback period and almost 75-80% probability. Based on the conducted VSM analysis of losses in the agri-food supply chain, there have been determined the main points, where it is advisable to conduct optimization changes for the achievement of positive results and the significant economic effect from the proposed measures has been confirmed. In further studies, it is recommended to focus on identifying the synergistic effect of the agri-food supply chain optimization on the basis of sustainable development.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• 제26권1호
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• pp.1-10
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• 2024

Objective: Endovascular coil embolization is the primary treatment modality for intracranial aneurysms. However, its long-term durability remains of concern, with a considerable proportion of cases requiring aneurysm reopening and retreatment. Therefore, establishing optimal follow-up imaging protocols is necessary to ensure a durable occlusion. This study aimed to develop guidelines for follow-up imaging strategies after endovascular treatment of intracranial aneurysms. Methods: A committee comprising members of the Korean Neuroendovascular Society and other relevant societies was formed. A literature review and analyses of the major published guidelines were conducted to gather evidence. A panel of 40 experts convened to achieve a consensus on the recommendations using the modified Delphi method. Results: The panel members reached the following consensus: 1. Schedule the initial follow-up imaging within 3-6 months of treatment. 2. Noninvasive imaging modalities, such as three-dimensional time-of-flight magnetic resonance angiography (MRA) or contrast-enhanced MRA, are alternatives to digital subtraction angiography (DSA) during the first follow-up. 3. Schedule mid-term follow-up imaging at 1, 2, 4, and 6 years after the initial treatment. 4. If noninvasive imaging reveals unstable changes in the treated aneurysms, DSA should be considered. 5. Consider late-term follow-up imaging every 3-5 years for lifelong monitoring of patients with unstable changes or at high risk of recurrence. Conclusions: The guidelines aim to provide physicians with the information to make informed decisions and provide patients with high-quality care. However, owing to a lack of specific recommendations and scientific data, these guidelines are based on expert consensus and should be considered in conjunction with individual patient characteristics and circumstances.

• 한국환경농학회지
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• 제36권4호
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• pp.249-255
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• 2017

BACKGROUND: Globally, mulberry (Morus sp.) is exploited for feeding leaf to silkworms in order to obtain silk fiber or for animal feedstock production. Also, mulberry fruit is known to a by-product that was produced from mulberry tree after harvesting leaves for silkworm rearing, as a yield and consumption of mulberry fruit was increased, it has been fixing to a newincome crop. Mulberry leaves and fruits are used for the health benefits of human beings. Mulberry contains various bioactive components, such as alkaloids and flavonoids. Mulberry flavonoids are an important part of the diet because of their effects on human nutrition. The flavonoids in mulberry leaf and fruit of 'Suhyang'(Morus alba L.) were determined. METHODS AND RESULTS: Flavonoids for mulberry leaf and fruit of 'Suhyang' were analysed using ultrahigh performance liquid chromatography coupled with diode array detection and quadrupole time-of-flight mass spectrometry (UPLC-DAD-QTOF/MS)technique. An UPLC-DAD-QTOF/MS system was used, and identification of mulberry leaves constituents was carried out on the basis of the complementary information obtained from LC spectra, MS ions, and MS/MS fragments. The mulberry leaf (16 flavonoids) and fruit (9 flavonoids) were isolated and analyzed from Suhyang using UPLC-DAD-QTOF/MS chromatogram. To the best of our knowledge, Quercetin 3-O-(6"-O-malonyl) glucoside and quercetin 3-O-rutinoside (rutin) was detected on the highest content in leaf and fruit, respectively and further research will be devoted to evaluate their biological activity. CONCLUSION: Obtaining information about the concentration of functional materials in mulberry leaves could contribute to the development and promotion of processed, functional products and offer possible industrial use of 'Suhyang', holding promises to enhance the overall profitability of sericulture.

• Journal of Microbiology and Biotechnology
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• 제27권8호
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• pp.1392-1400
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• 2017

Galactooligosaccharides (GOSs) are known to be selectively utilized by Bifidobacterium, which can bring about healthy changes of the composition of intestinal microflora. In this study, ${\beta}-GOS$ were synthesized using bifidobacterial ${\beta}-galactosidase$ (G1) purified from recombinant E. coli with a high GOS yield and with high productivity and enhanced bifidogenic activity. The purified recombinant G1 showed maximum production of ${\beta}-GOSs$ at pH 8.5 and $45^{\circ}C$. A matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis of the major peaks of the produced ${\beta}-GOSs$ showed MW of 527 and 689, indicating the synthesis of ${\beta}-GOSs$ at degrees of polymerization (DP) of 3 and DP4, respectively. The trisaccharides were identified as ${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-glucopyranose, and the tetrasaccharides were identified as ${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-glucopyranose. The maximal production yield of GOSs was as high as 25.3% (w/v) using purified recombinant ${\beta}-galactosidase$ and 36% (w/v) of lactose as a substrate at pH 8.5 and $45^{\circ}C$. After 140 min of the reaction under this condition, 268.3 g/l of GOSs was obtained. With regard to the prebiotic effect, all of the tested Bifidobacterium except for B. breve grew well in BHI medium containing ${\beta}-GOS$ as a sole carbon source, whereas lactobacilli and Streptococcus thermophilus scarcely grew in the same medium. Only Bacteroides fragilis, Clostridium ramosum, and Enterobacter cloacae among the 17 pathogens tested grew in BHI medium containing ${\beta}-GOS$ as a sole carbon source; the remaining pathogens did not grow in the same medium. Consequently, the ${\beta}-GOS$ are expected to contribute to the beneficial change of intestinal microbial flora.

• Archives of Pharmacal Research
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• 제29권3호
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• pp.224-234
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• 2006

We employed human SK-MEL-28 cells as a model system to identify cellular proteins that accompany N-(4-methyl)phenyl-O-(4-methoxy)phenyl-thionocarbamate (MMTC)-induced apoptosis based on a proteomic approach. Cell viability tests revealed that SK-MEL-28 skin cancer cells underwent more cell death than normal HaCaT cells in a dose-dependent manner after treatment with MMTC. Two-dimensional electrophoresis in conjunction with matrixassisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry analysis or computer matching with a protein database further revealed that the MMTC-induced apoptosis is accompanied by increased levels of caspase-1, checkpoint suppressor-1, caspase-4, NF-kB inhibitor, AP-2, c-Jun-N-terminal kinase, melanoma inhibitor, granzyme K, G1/S specific cyclin D3, cystein rich protein, Ras-related protein Rab-37 or Ras-related protein Rab-13, and reduced levels of EMS (oncogene), ATP synthase, tyrosine-phosphatase, Cdc25c, 14-3-3 protein or specific structure of nuclear receptor. The migration suppressing effect of MMTC on SK-MEL-28 cell was tested. MMTC suppressed the metastasis of SK-MEL-8 cells. It was also identified that MMTC had little angiogenic effect because it did not suppress the proliferation of HUVEC cell line. These results suggest that MMTC is a novel chemotherapeutic and metastatic agents against the SK-MEL-28 human melanoma cell line.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.312-312
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• 2022

Peanut hull as by-product has been discarded during peanut processing. However, peanut hull contains plenty of polyphenols that shows various physiological activities. The objectives of this study were to investigate anti-inflammatory and enzyme inhibitory activities of polyphenols from 'Sinpalkwang' peanut (Arachis hypogaea L.) hull. Compounds were isolated from methanol extracts of peanut hull by preparative-high performance liquid chromatography after identifying and quantifying polyphenols using Ultra performance liquid chromatography (UPLC) and UPLC-Quadrupole time-of-flight-mass spectrometry profiling. The structures of compounds were elucidated by one-dimensional [¹H, ¹³C] nuclear magnetic resonance (NMR) and two-dimensional NMR (correlated spectroscopy, heteronuclear single quantum coherence and heteronuclear multiple bond correlation). Three compounds were identified as 5,7-dihydroxy-4H-chromen-4-one (peak 2), luteolin (peak 4) and eriodictyol (peak 5). Significant differences in inflammatory mediator such as nitric oxide (NO), interleukin-6 (IL-6) and interleukin-1β (IL-lβ) in lipopolysaccharide stimulated Raw 264.7 macrophages and in enzyme (xanthine oxidase [XO] and α-glucosidase [AG]) inhibitory activities were observed between three compounds (p < 0.05). Peak 5 treated Raw 264.7 macrophages showed lower content of NO (16.4 uM), IL-6 (7.0 ng/mL), and IL-1β (60.6 pg/mL) than peak 2 (NO: 28.3 uM, IL-6: 11.3 ng/mL, IL-1β: 66.9 pg/mL) and peak 4 (NO: 24.7 uM, IL-6: 9.3 ng/mL, IL-1β: 62.6 pg/mL). Peak 5 showed higher XO inhibitory activity (84.7%) and higher AG inhibitory activity (52.4%) than peak 2 (XO inhibitory activity: 45.4%, AG inhibitory activity: 21.6%) and peak 4 (XO inhibitory activity: 37.9%, AG inhibitory activity: 37.5%) at concentration of 0.5mg/mL. This study suggests that peanut hull could be a potential source of anti-inflammatory and physiological materials while creating new use of discarded peanut hull as by-products concomitantly.

• 공업화학
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• 제28권3호
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• pp.263-271
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• 2017

최근에, 질량분석기술의 폴리머 분석에의 응용은 MALDI-TOF MS 개발 이후 급속도로 발전하였다. 이 리뷰 논문은 현재까지 연구된 MALDI-TOF MS의 폴리머 특성분석에의 응용에 관한 최신 논문을 정리하였다. MALDI-TOF MS는 바이오 폴리머와, 합성 폴리머의 평균분자량 분석, 폴리머의 시퀀스 분석을 통한 구조의 해석, 모노머의 조성분석에까지 이용되고 있다. 엔드그룹의 특성과 농도를 분석하는 연구도 많이 진행되었고, 복잡한 폴리머의 분자량의 분석에는 SEC와 MALDI-TOF MS를 연결한 분석법을 추천한다. MALDI에 tandem MS를 결합한 분석기술이나, 이온 모빌리티를 응용한 질량분석기, TOF-SIMS, MALDI-TOF-Imaging 기술도 급격히 발전하고 있으며, 이의 폴리머 특성분석에의 응용은 별도의 분리기술이 필요 없어 앞으로 더 많이 이용될 것으로 생각된다. 분자량, 시퀀스, 그리고 모노머의 조성을 정확하게 계산해주는 소프트웨어와 고분자량(> 100 kDa)의 분석을 가능하게 해주는 기술이 개발된다면, 폴리머를 연구하는 과학자들에게 MALDI-TOF MS의 이용은 문제점을 해결하고, 목적하는 폴리머를 합성하는 데 중요한 수단이 될 것이다.

• 항공우주정책ㆍ법학회지
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• 제19권1호
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• pp.109-139
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• 2004

라이트형제에 의한 비행기(飛行機)의 개발(開發)은 동세기(同世紀) 항공공학(航空工學)의 급속(急速))한 발전(發展)을 이루어 항공기를 이용하여 태평양을 횡단하고, 소리의 속도보다 빠르게 비행하게 되었으며, 수백명이 우주(宇宙) 비행(飛行)을 하였고, 10여명이 달에 다녀왔다. 그러나 이 경이로운 인간의 기술이면에는 항공기의 개발과 더불어 항공사고라는 난점이 자리하고 있다. 항공의 발달은 운송수단으로서 타 교통수단의 경쟁을 유도하였고, 항공산업의 획기적인 발달을 이룩하여 모든 여행객들과 물류수송에 선도적인 역할을 담당하고 있다. 그러나, 항공활동의 증가는 대조적으로 항공사고를 수반하게 되고, 사고시는 막대한 인명과 재산피해를 동반하게 된다. 따라서 향후 개발되는 항공기 의 초대형화와 신기술 개발 및 항공 교통량의 증가에 비례하여 항공사고건수 또한 증가할 것이며 항공사고는 인명 및 재산피해의 초대형화를 동반할 것이다. 이러한 항공사고 방지를 위해 사고조사의 전문화, 체계화 및 과학화가 필수적이다. 이를 달성하기 위한 항공사고 조사기구의 효율적인 역할을 수행하기 위하여는 사고조사위원회 위원의 상근화, 통합적사고 조사기구의 신설, 사고조사관의 제도적 신분보장, 인적요소분야 사고조사관의 확보(確保), 사고조사관의 법적 책임 한계, 사고(accident)와 중대한 준사고(serious incident)에 대한 정의와 조사범위, 그리고 민간항공기와 국가항공기가 연관된 사고 발생시 조사의 주체가 관련규정에 명시될 필요성이 개선방안(改善方案)으로 연구되었다.