• 한국환경과학회지
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• 제30권12호
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• pp.1081-1092
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• 2021

In this study, the effect on the stability of Aerobic Granular Sludge (AGS) caused by an AGS separator was investigated. The AGS separator was a hydrocyclone. The main factors of the AGS separator were filter pore size (0.125~0.600 mm), conical-to-cylindrical ratio (1.5~3.0), and operating time (1~20 min). The AGS/mixed liquor suspended solid (MLSS) ratio gradually increased to 0.500 mm (AGS/MLSS: 84.3±3.0%). AGS was best separated at the conical-to-cylindrical ratio of 2.5 (AGS/MLSS: 84.7±3.3%). As the operating time increased, the AGS separation performance also tended to increase. The shortest AGS separator run time, but the highest AGS separation performance was 10 min (87.0±2.5%). AGS stability was evaluated by operating the selected AGS separator and sequencing batch reactor. The average removal efficiencies of TOC, TCOD_Cr, SS, TN, and TP were 95.7%, 96.9%, 93.0%, 89.0%, and 96.2%, respectively, which met the effluent standards in Korea. In addition, the AGS/MLSS ratio tended to remain constant, and the sludge volume index demonstrated a tendency to decrease from 140 mL/g to 70 mL/g. During the operation, the particles of AGS in optical microscope observations gradually increased.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 제5회 압연심포지엄 신 시장 개척을 위한 압연기술
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• pp.297-306
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• 2004

This study investigated Austenite Grain Size (AGS) distribution in Low-Speed Round-Oval Rolling. Rolling experiments were done along with the AGS numerical modeling to characterize the final AGS distribution and its kinetics behavior. For bar rolling experiment, we utilized the pilot rolling mill, operating at 34 fixed rpm, at POSCO Technical Research Laboratories. To investigate the microstructural observation, the rigid-viscoplastic finite element analysis was combined with Hodgson's AGS evolution model. To consider the transient thermal history in the integrative AGS modeling, additivity rule was introduced. The integrated analysis revealed that static or meta-dynamic recrystallization is responsible for the AGS difference in the inner or outer region of rolled bar. Comparative study showed that the current AGS modeling approach can be used to model the overall AGS distribution in bar rolling processes. For more accurate AGS prediction, the AGS modeling method should be verified under the various rolling conditions such as different rolling speeds and different deformations.

• Archives of Pharmacal Research
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• 제6권1호
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• pp.93-102
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• 1983

Waksman's group discovered SM in 1944, and opened a new field of antibiotcs: i. e. AGs. A large group of antibiotics containing aminosugar and/or aminocyclitol is called the AGs. A majority of AGs are produced by actinomycetes. In the first period, AGs effective against tuberculosis were chiefly examined. Following the studies on NM and KM, AGs active against staphyllococci and gram-negative robs were investigated. The discovery of GM and synthesis of DKB and AMK led to the studies on the third generation AGs, which show a broad antimicrobial spectrum including Pseudomonas aeruginosa and drug-resistant bacteria. Since opportunistic infection caused by drug-resistant bacteria are increasing, the third generation AGs are extensively investigated at present.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 제5회 압연심포지엄 신 시장 개척을 위한 압연기술
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• pp.317-326
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• 2004

This study investigated tile local austenite grain size (AGS) distribution In rolling of SCM435 steel which is commonly used for high strength bolt. To investigate AGS distribution, round-oval (R-O) and square-diamond (S-D) rolling experiments were carried out with pilot mill. In round-oval rolling, local AGS has a tendency to increase when it goes to outward. In square-diamond rolling, local AGS has a tendency to increase when it goes to free surface. To investigate relation between AGS and process parameter, three dimensional FE analysis was carried out along with rolling experiment. To validate accuracy of FE analysis, we compared deformed geometry with FE result. The AGS prediction combined AGS model with numerical analysis was also carried out for center node of S-D rolling. Although this study brought experimental observation and its qualitative analysis into focus and quantitative AGS prediction will be done as a further work.

• 한국환경과학회지
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• 제31권4호
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• pp.295-309
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• 2022

The purpose of this study was to evaluate the operational characteristics of wastewater treatment using Sequencing Batch Reactor (SBR) with Aerobic Granular Sludge (AGS) separator in the pilot plant. Pilot plant experiments were conducted using SBR with AGS separator and pollution removal efficiencies were evaluated based on the operational condition and surface properties of AGS. The results of the operation on water quality of the effluent showed that the average concentration of total organic carbon, suspended solids, nitrogen, and phosphorus was 6.89 mg/L, 7.33 mg/L, 7.33 mg/L, and 0.2 mg/L, respectively. All these concentrations complied the effluent standard in Korea. The concentration of mixed liquor suspended solid (MLSS) fluctuated, but the AGS/MLSS ratio was constant at 86.5±1.3%. Although the AGS/MLSS ratio was constant, sludge volume index improved. These results suggested that the particle discharged fine sludge and increased the AGS praticle size in the AGS. Optical microscopy revealed the presence of dense AGS at the end of the operation, and particles of > 0.6 mm were found. Compared to those of belt-type AGS separator, the required area and power consumption of the hydrocyclone-type AGS separator were reduced by 27.5% and 83.8%, respectively.

• Environmental Engineering Research
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• 제24권2호
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• pp.238-245
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• 2019

This study investigated the characteristic of aerobic granular sludge (AGS) process to treat the sewage having low carbon/nitrogen ratio (Biochemical oxygen demand ($BOD_5$):Total nitrogen (T-N), 4.5:1) in sequencing batch reactor (SBR). The removal efficiency of $BOD_5$, suspended solid (SS), T-N and phosphorus ($PO_4{^{3-}}$-P) were 92.6%, 64.3% and 90.1%. Concentration and size of AGS were changed in proportion to the organic matters and nitrogen concentration of the influent (Concentration and size of AGS: 1,700-3,000 mg/L, 0.5-1.0 mm). Mixed liquor suspended solid (MLSS) also changed with the concentration of AGS (MLSS: 2,000-3,500 mg/L). When the settling time was shortened from 15 min to 10 min, size and shape of AGS were maintained (Size of AGS: 1.0-1.5 mm). In addition, the concentration of AGS and MLSS increased (Concentration of AGS: 3,500 mg/L, MLSS: 4,000 mg/L). Concentration, size and shape of AGS were affected the settling time of the reactor more than the concentration of organic matter and nitrogen in the influent. In the results of removal efficiency and changes in AGS, we confirmed that the SBR process using AGS can be used to treat the sewage having low carbon/nitrogen ratio by applying short settling time.

• Journal of Microbiology and Biotechnology
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• 제25권9호
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• pp.1485-1492
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• 2015

Makgeolli is a traditional wine in Korea and has been traditionally believed to exhibit health benefits. However, the inhibitory effect of dealcoholized makgeolli (MK) on cancer has never been investigated scientifically. In this study, MK exhibited an anti-angiogenic effect by inhibiting tube formation in human umbilical vein endothelial cells, without cytotoxicity. Treatment with MK reduced the proliferation of AGS human gastric adenocarcinoma cells in a dose-dependent manner and increased the sub-G1 population. Next, we evaluated whether MK could induce apoptosis in AGS cells by using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay or Annexin V method. Treatment with MK at 500 and 1,000 μg/ml increased the number of TUNEL-positive AGS cells. Under the same conditions, MK-treated (500 and 1,000 μg/ml) cells showed significant induction of early or late apoptosis, compared with untreated cells (no induction). In addition, MK also induced phosphatase and tensin homolog (PTEN) expression in AGS cells. However, p53 expression in AGS cells was not changed by MK treatment. Furthermore, MK at 500 mg/kg·d reduced the tumor size and volume in AGS tumor xenografts. Taken together, MK may be useful for the prevention of cancer cell growth.

• 대한예방한의학회지
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• 제15권3호
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• pp.127-140
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• 2011

Objectives : The research was conducted to confirm the effect of Acanthopanax senticosus harms(ASH) on the anti-tumor activities in AGS human gastric cancer cells. Methods : To examine the potential anti-tumor effect of ASH, we performed many experiments. After processing AGS cancer cells with varying concentrations 80% ethanol ASH extract, analyses by MTT, flow cytometer(FACS) and western blot were used. Results : AGS cancer cells showed decreased cell proliferation and increased contents of S phase when treated with ASH. Moreover, the Western blot experiment showed that ASH affected S phase cell cycle-related molecules(Cyclin A, p21 and p16) in AGS cells. ASH also inhibited EGFR-STAT3 pathway in AGS human gastric cancer cells. Conclusion : Based on these results, we observed that ASH arrested the cell cycle at S phase and inhibited the phosphorylation of EGFR and STAT3 proteins which reduce the cell cycle and the manifestation of the genes that are related to inhibiting cell growth in AGS cells. It can be concluded that ASH can be used in developing medicine for gastric cancer.

• 한국물환경학회지
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• 제37권1호
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• pp.47-54
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• 2021

Aerobic granular sludge (AGS) can be classified as a type of self-immobilized microbial aggregates measuring more than 0.2 mm. It offers the option to simultaneously remove COD, N, and P that occur in different zones inside a granule. Also, AGS is characterized by high precipitability, treatability with high organic loading, and high tolerance to low temperature. In this study, a sequencing batch reactor inoculated with AGS (AGS-SBR) is a new advanced wastewater treatment process that was proven to grow AGS with integrated nutrient removal and low C/N ratio. A pilot plant, AGS-SBR with a capacity of 225 ㎥/d was installed at an S sewage treatment plant in Gyeonggi-do. The results of the operation showed that the water quality of the effluent indicated that the value of BOD5 was 1.5 mg/L, CODMn was 11.4 mg/L, SS was 6.2 mg/L, T-N was 13.2 mg/L, and T-P was 0.197 mg/L, and all of these values reliably satisfied an effluent standard (I Area). In winter, the T-N treatment efficiency at a lower temperature of less than 11℃ also showed reliability to meet the effluent standard of the I Area (20 mg/L or less). Analysis of microbial community in AGS showed a higher preponderance of beneficial microorganisms involved in denitrification and phosphorus accumulation compared with activated sludge. The power consumption and sludge disposal cost were reduced by 34.7% and 54.9%, respectively, compared to the domestic SBR type sewage treatment plant with a processing capacity of 1,000 ㎥/d or less.

• 한국식품위생안전성학회지
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• 제36권1호
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• pp.100-104
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• 2021

트랜스 신남알데하이드(TCA)는 계피의 활성성분 중 하나로 알려져 있으며, 항바이러스, 항균, 항진균 뿐 아니라 일부 암세포주에서 항암 작용이 있다고 보고된 바 있다. 하지만, 위암세포주에서의 보고는 미비하며 그 작용기전에 대해서는 밝혀진 바가 없다. 본 연구에서는 위암 AGS 세포주에 대한 증식 억제작용 및 그 기전을 살펴보았다. TCA는 농도의존적으로 AGS 세포의 생존율을 억제하였다. AGS 세포 형태로 보아 TCA에 의한 세포사멸을 확인할 수 있었다. 그 기전을 확인하기 위하여, 세포사멸 관련 단백질의 발현양을 조사한 결과, TCA는 p53과 Bax의 단백질 발현을 증가시켰다. 또한, 분절된 caspase 9 및 PARP의 발현이 증가되는 것으로부터 TCA가 AGS 세포주의 세포사멸을 유도하였음을 알 수 있었다. 본 연구결과로부터 TCA가 위암에 대한 항암 활성이 있음을 확인하였으며, 추후 지속적인 연구를 통해 항암제 후보물질로 기대된다.