Development of Simultaneous Analytical Method for ImidazolinoneHerbicides from Livestock using LC-MSMS

Hyo-Min Heo,Hyeong-WookJo,Kyu-Won Hwang,Jung-Hun Sun,Joon-Kwan Moon 한국농약과학회 2021 한국농약과학회 학술발표대회 논문집 Vol.2021 No.11

Simultaneous analytical method using LC/MSMS for imidazolinone herbicides from livestock (egg, milk, beef, pork and chicken) for monitoring was developed with QuEChERS preparation. Sample weighing (5g) in a 50mL conical tube, added 0.1 M potassium phosphate dibasic solution (5mL) was shaken for 10min. After 0.5mL 6 NHCl, 10mL acetonitrile were added, it was shaken for 10min. And QuEChERS extraction salt (Original method, 4g MgSO₄, 1g NaCl) were added to the sample in the 50 mL conical tube. The mixture was strongly shaken for 1 min and was centrifuged at 3,000g for 10 min. The acetonitrile layer was purification with dSPE (150mg MgSO₄, 25mg C18) and was centrifuged at 13,000g for 5min. The supernatant was filtered with a membrane filters (pore size: 0.2um) before analysis. ME (%, Matrix effect) for almost analytes range were -6.56 to 5.70%. MLOD (Method LOD) and MLOQ (Method LOQ) was calculated by S/N ratio. MLOQs were 0.01 mg/kg. The linear correlation coefficients (r2) were > 0.99 within the range of 2 ~ 100 ug/kg for all of the 3 imidazolinone herbicides. The percentages (of imidazolinone herbicides) recovers were in the range of 84.1 ~ 110.6% (0.01mg/kg level), 90.8 ~ 97.1% (0.1mg/kg level) and 94.4 ~ 102.1% (0.5mg/kg level) within the validation criteria (recover; 70-120% with RSD < 20%)

국내외 수용가 맞춤형 수력발전시스템 현대화개발 및 실증

오민환(Min-Hwan Oh),신기석(Ki-Seok Shin),임재황(Jae-Hwang Lim),윤여창(Yeo-Chang Yun),김현아(Hyun-Ah Kim),강석원(Seok-Won Kang),백종명(Jong-Myung Paik),이준용(Jun-Yong Lee) 대한전기학회 2017 대한전기학회 학술대회 논문집 Vol.2017 No.10

Ex Vivo Live Full-Thickness Porcine Skin Model as a Versatile In Vitro Testing Method for Skin Barrier Research

( Jee-hyun Hwang ),( Haengdueng Jeong ),( Nahyun Lee ),( Sumin Hur ),( Nakyum Lee ),( Jeong Jun Han ),( Hye Won Jang ),( Wang Keun Choi ),( Ki Taek Nam ),( Kyung-min Lim ) 한국피부장벽학회 2021 한국피부장벽학회지 Vol.23 No.2

Since the European Union (EU) announced their animal testing ban in 2013, all animal experiments related to cosmetics have been prohibited. Here, we investigated whether an ex vivo live porcine skin model can be employed to study the safety and skin barrier-improving effects of hydroxyacids widely used in cosmetics for keratolytic peels. Glycolic acid (1-10%), salicylic acid (0.2-2%), and lactobionic acid (1.2-12%) were used as representative substances for α-hydroxyacid (AHA), β-hydroxyacid (BHA), and polyhydroxyacid (PHA), respectively. When hydroxyacids were applied at high concentrations on the porcine skin every other day for 6 days, tissue viability was reduced to 50-80%, suggesting that the toxicity of cosmetic ingredients can be evaluated with this model. Based on tissue viability, the treatment scheme was changed to a single exposure for 20 min. The protective effects of a single exposure of hydroxyacids on skin barrier function were evaluated by examining rhodamine permeability and epidermal structural components of barrier function using immunohistochemistry (IHC) and immunofluorescence (IF) staining. Lactobionic acid (PHAs) improved skin barrier function most compared to other AHAs and BHAs. Most importantly, trans-epidermal water loss (TEWL), an important functional marker of skin barrier function, could be measured with this model, which confirmed the significant skin barrier-protective effects of PHAs. Collectively, we demonstrated that the ex vivo live full-thickness porcine skin model can be an excellent alternative to animal experiments for skin studies on the safety and efficacy of cosmetic ingredients. Funding: This study was funded by the Health Technology R&D Project, Ministry of Health and Welfare, Republic of Korea (Grant no. HP20C0061).

황구침법(黃丘鍼法)을 이용한 고혈압 환자의 혈압강하 효과에 대한 증례보고

한창현 ( Chang Hyun Han ),황치원 ( Chi Won Hwang ),신미숙 ( Min Suk Shin ),신선화 ( Seon Hwa Shin ),최선미 ( Sun Mi Choi ) 대한경락경혈학회 2006 Korean Journal of Acupuncture Vol.23 No.3

Objectives: The aim of the study was to investigate the antihypertensive effect of Hwang-gu Acupuncture in hypertensive patients. Methods: We measured the blood pressure of the patients who were admitted in the Oriental Medical Clinic of Brother from 25th November 2005 to 27th March 2006. We included the patients only in case of the systolic blood pressure was over 140mmHg or diastolic blood pressure was over 90mmHg, Twenty two patients were treated by Hwang-gu Acupuncture. In order to evaluate the effect of the Hwang-gu Acupuncture, the blood pressure was measured before and after Acupuncture procedure total 4 times, 10times. Results: There were a significant decrease in the systolic blood pressure and significant decrease in the diastolic blood pressure by Hwang-gu Acupuncture 4 times. The effect of Hwang-gu Acupuncture by measurement time on blood pressure were follows: In a systolic blood pressure was gradually deceased significantly from 1st to 4th but diastolic blood pressure was significantly decreased after 2nd and 4th only. Conclusions: These results suggest that Hwang-gu Acupuncture is effective in decreasing the systolic and diastolic blood pressure.

Development of Self-microemulsifying Drug Delivery System for Enhancing the Bioavailability of Atorvastatin

( Shun Ji Jin ),( Won Kyung Cho ),( Hee Jun Park ),( Kwang Ho Cha ),( Jun Sung Park ),( Ja Seong Koo ),( Hun Sik Wang ),( Jeong Soo Kim ),( Min Soo Kim ),( Sung Joo Hwang ) 한국약제학회 2011 Journal of Pharmaceutical Investigation Vol.41 No.2

The objective of the study was to prepare self-microeulsifying drug delivery system (SMEDDS) incorporating atorvastatin calcium and evaluate its properties and oral bioavailability. Solubility of atorvastatin in various vehicles was determined. Pseudo-ternary phase diagrams were constructed to identify the good self-emulsification region. The droplet size distributions of the resultant emulsions were determined by dynamic light scattering measurement. The mean droplet size of chosen formulation (20% ethyl oleate, 40% tween-80, 40% Carbitol(R)) was 23.4±1.3 nm. The SMEDDS incorporating atorvastatin calcium appeared to be associated with better performance in dissolution and pharmacokinetic studies, compared with raw atorvastatin calcium. In dissolution test, the release percentage of atorvastatin from SMEDDS mixture could rapidly reach more than 95% within 3 min. Oral AUC0→8(hr)values in SD rats was 1994±335 ng·hr/mL, which significantly increased (P<0.05) compared with raw atorvastatin calcium. The SMEDDS formulation was relatively stable when stored at 4˚C during 3 months. Our studies illustrated the potential use of SMEDDS for the delivery of hydrophobic compounds, such as atorvastatin, by the oral route.

온도 유지시간 제어를 적용한 하이브리드 분말 압출 공정을 통한 요구 특성의 스퍼기어 제조

이경훈(Kyung Hun Lee),황대원(Dae Won Hwang),김병민(Byung Min Kim) 대한기계학회 2011 大韓機械學會論文集A Vol.35 No.8

본 연구는 압출 시 성형온도를 유지하여 Zn-22Al 합금분말의 성형성을 향상시키는 하이브리드 분말 압출 공정의 개발 및 온도 유지시간이 압출된 스퍼기어의 기계적 특성에 미치는 영향을 조사하기 위해 수행되었다. 피치원 지름 1.8mm 의 소형 스퍼기어는 압출온도 290, 300, 310℃에서 성형되었다. 볼밀시간 32h 의 Zn-22Al 합금분말을 압출온도 310℃에서 압출 시 표면 결함이 없는 소형 기어가 제조되었다. 경도분포는 기어 중심부와 치형부에서 불균일하였고 소결공정 후 내부 변형에너지의 차이로 인해 내부균열이 발생하였다. 위와 같은 문제를 해결하기 위해 온도 유지시간 제어를 이용한 하이브리드 압출 연구를 수행하였다. 압출된 스퍼기어의 평가는 압출하중, 비커스 경도 및 치수정밀도 측정을 통해 이루어졌다. 온도 유지시간 15min 에서 압출된 스퍼기어의 기계적 성질이 가장 우수하였다. In this study, a hybrid powder-extrusion process involving the control of temperature dwelling time for improving the formability of Zn-22Al powder was developed and the effect of dwelling time on the mechanical properties of a spur gear with a pitch circle having a diameter of 1.8 mm was investigated. General extrusion experiments were carried out at different temperatures such as 290, 300, and 310°C. Spur gears with good qualities and without any surface defects were obtained in the case of extrusion temperature of 310°C and ball-milling duration of 32 h. The Vickers hardness distribution was non-uniform, and after the sintering process, an internal crack was generated because of the different deformation energy between gear central part and teeth. To overcome the abovementioned problems, research on controlling the dwelling time of the extrusion temperature in the powder-extrusion process was carried out. Good-quality spur gears were obtained when the dwelling time was 15 min.

Fast and Scalable Hydrodynamic Synthesis of MnO₂/Defect-Free Graphene Nanocomposites with High Rate Capability and Long Cycle Life

Hong, Seok Bok,Jeong, Jae-Min,Kang, Heon Gyu,Seo, Donghyuk,Cha, Younghyun,Jeon, Hyeonyeol,Lee, Geun Young,Irshad, Mobina,Kim, Do Hyun,Hwang, Sung Yeon,Kim, Jung Won,Choi, Bong Gill American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.41

<P>The integration of metal oxides and carbon materials provides a great potential for enhancing the high energy and power densities of supercapacitors, but the rational design and scalable fabrication of such composite materials still remain a challenge. Herein, we report a fast, scalable, and one-pot hydrodynamic synthesis for preparing ion conductive and defect-free graphene from graphite and MnO<SUB>2</SUB>/graphene nanocomposites. The use of this hydrodynamic method using Taylor-Couette flow allows us to efficiently fast shear-exfoliate graphite into large quantities of high-quality graphene sheets. Deposition of MnO<SUB>2</SUB> on graphene is subsequently performed in a fluidic reactor within 10 min. The prepared MnO<SUB>2</SUB>/graphene nanocomposite shows outstanding electrochemical performances, such as a high specific capacitance of 679 F/g at 25 mV/s, a high rate capability of 74.7% retention at an extremely high rate of 1000 mV/s, and an excellent cycling characteristic (∼94.7% retention over 20 000 cycles). An asymmetric supercapacitor device is fabricated by assembling an anode of graphene and a cathode of MnO<SUB>2</SUB>/graphene, which resulted in high energy (35.2 W h/kg) and power (7.4 kW/kg) densities (accounting for the mass of both electrodes and the electrolyte) with a high rate capability and long cycle life.</P> [FIG OMISSION]</BR>

서남해안 2.5GW 해상풍력단지 건설의 경제효과분석

박재필 ( Jae Pil Park ),김민영 ( Min Young Kim ),황성원 ( Sung Won Hwang ),김형성 ( Hyoung Sung Kim ) 한국도서(섬)학회 2014 韓國島嶼硏究 Vol.26 No.3

MOTIE(Ministry of Trade, Industry & Energy) aims to build a Southwest 2.5GW offshore wind farm. The job will require help from the government, electric operator and manufacturers. The domestic offshore wind farm market will boost global competitiveness up until 2019. This research analyzes the economic impact of the offshore wind farm project. The local acceptance in terms of production, employment and value added are expected to be maximized. According to the quantitative analysis using the extended 2010 input-output table, we calculated that the production inducement impact will reach up to 13.5 trillion won. 11.07 trillion won from the offshore wind farm industry and 2.4 trillion won from others. Furthermore the impact of increase in employment is expected to reach 22,662. 9,883 will be from the wind farm industry and 12,779 from other fields. The impact is expected to be greater especially during the middle of the jobless growth period, Lastly, the value added inducement impact is expected to be 4.24 trillion won. Regarding economic impacts, strategies required for increasing local acceptance are as follows. First, in order to diversify and sophisticate the primary industry into a secondary or tertiary one, we need to develop the nearby wind farm site into a wind farm thema park. Attracting the wind farm production, installing and maintaining/repairing firms and establishing an experience center for K-12 students by providing them an education center for offshore wind energy can be specific means of development. Also, during the operation and after the destruction of facilities, the government should lay out the sub-structure of the wind farm as a sea ranch. Thirdly, the level of local acceptance regarding the community ownership of the offshore wind farm should increase to those of Middelgrunden(Denmark) and Navarra(Spain). Considering the economic condition of Buan, Gochang and the Yeonggwang area, community ownership is one of best solutions for the increment of local tax revenue. At last, considering the supports system of areas adjacent to power plants and ``Partnership management with local community’, the offshore wind farm operator may need to provide assistant policies to nearby communities. The policies should be based on Corporate Social Responsibility(CSR) such as education scholarship projects, local economy cooperative projects, sports/culture projects.

Differential Effects of Pioglitazone in the Hippocampal CA1 Region Following Transient Forebrain Ischemia in Low- and High-Fat Diet-Fed Gerbils.

Moon, Seung Myung,Choi, Goang-Min,Yoo, Dae Young,Jung, Hyo Young,Yim, Hee Sun,Kim, Dae Won,Hwang, In Koo,Cho, Byung Moon,Chang, In Bok,Cho, Sung-Min,Won, Moo-Ho Kluwer Academic/Plenum Publishers 2015 Neurochem Res Vol.40 No.5

<P>In the present study, we investigated the effects of pioglitazone (PGZ) in the hippocampal CA1 region of low- or high-fat diet (LFD or HFD) fed gerbils after transient forebrain ischemia. After 8 weeks of LFD or HFD feeding, PGZ (30 mg/kg) was intraperitoneally administered to the gerbils, following which ischemia was induced by occlusion of the bilateral common carotid arteries for 5 min. Administration of PGZ significantly reduced the ischemia-induced hyperactivity 1 day after ischemia/reperfusion in both LFD- and HFD-fed gerbils. At 4 days after ischemia/reperfusion, the neurons were significantly reduced and microglial activation was observed in the hippocampal CA1 region in LFD- and HFD-fed gerbils. The microglial activation was more prominent in the HFD-fed gerbils compared to the LFD-fed gerbils. Administration of PGZ ameliorated ischemia-induced neuronal death and microglial activation in the hippocampal CA1 region 4 days after ischemia/reperfusion in the LFD-fed gerbils, but not in the HFD-gerbils. At 6 h after ischemia/reperfusion, tumor necrosis factor-α (TNF-α) and interlukin-1β (IL-1β) levels were significantly increased in the hippocampal homogenates of LFD-fed group compared to control group, and HFD feeding further increased TNF-α and IL-1β levels. PGZ treatment significantly ameliorated the increase of TNF-α and IL-1β levels in LFD-fed gerbils, not in the HFD-fed gerbils. At 12 h after ischemia/reperfusion, superoxide dismutase (SOD) and malondialdehyde (MDA) levels in hippocampal homogenates were significantly increased in the LFD-fed group compared to the control group, and HFD feeding significantly showed relatively reduction in SOD activity and increase in MDA level. PGZ administration significantly reduced the increase in MDA levels 12 h after ischemia/reperfusion in the LFD-fed gerbils, but not in the HFD-fed gerbils. These results suggest that PGZ ameliorates the neuronal damage induced by ischemia by maintaining the TNF-α, IL-1β, SOD and MDA levels in LFD-fed gerbils. In addition, HFD feeding affects the modulation of these parameters in the hippocampus after transient forebrain ischemia.</P>

알루미나이드 확산코팅된 스테인레스 합금의 내산화 및 내삭마 특성

황철홍,이효민,오정석,황동현,황유석,이종원,최정묵,박준식,Hwang, Cheol Hong,Lee, Hyo Min,Oh, Jeong Seok,Hwang, Dong Hyeon,Hwang, Yu Seok,Lee, Jong Won,Choi, Jeong Mook,Park, Joon Sik 한국분말재료학회 (*구 분말야금학회) 2021 한국분말재료학회지 (KPMI) Vol.28 No.5

Stainless steel, a type of steel used for high-temperature parts, may cause damage when exposed to high temperatures, requiring additional coatings. In particular, the Cr₂O₃ product layer is unstable at 1000℃ and higher temperatures; therefore, it is necessary to improve the oxidation resistance. In this study, an aluminide (Fe₂Al₅ and FeAl₃) coating layer was formed on the surface of STS 630 specimens through Al diffusion coatings from 500℃ to 700℃ for up to 25 h. Because the coating layers of Fe₂Al₅ and FeAl₃ could not withstand temperatures above 1200℃, an Al₂O₃ coating layer is deposited on the surface through static oxidation treatment at 500℃ for 10 h. To confirm the ablation resistance of the resulting coating layer, dynamic flame exposure tests were conducted at 1350℃ for 5-15 min. Excellent oxidation resistance is observed in the coated base material beneath the aluminide layer. The conditions of the flame tests and coating are discussed in terms of microstructural variations.