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%)

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.

Dry etching of polydimethylsiloxane using microwave plasma

Hwang, Sung Jin,Oh, Dong Joon,Jung, Phill Gu,Lee, Sang Min,Go, Jeung Sang,Kim, Joon-Ho,Hwang, Kyu-Youn,Ko, Jong Soo IOP 2009 JOURNAL OF MICROMECHANICS AND MICROENGINEERING - Vol.19 No.9

<P>This paper presents a new polydimethylsiloxane (PDMS) dry-etching method that uses microwave plasma. The applicability of the method for fabricating microstructures and removing residual PDMS is also verified. The etch rate of PDMS was dominantly influenced by the gas flux ratio of CF<SUB>4</SUB>/O<SUB>2</SUB> and the microwave power. While the PDMS etch rate increased as the flux ratio of CF<SUB>4</SUB> was increased, the etch rate decreased as the flux ratio of O<SUB>2</SUB> was increased. The maximum etch rate of 4.31 µm min<SUP>−1</SUP> was achieved when mixing oxygen (O<SUB>2</SUB>) and tetrafluoromethane (CF<SUB>4</SUB>) at a 1:2 ratio at 800 W power. The PDMS etch rate almost linearly increased with the microwave power. The ratio of the vertical etch rate to the lateral etch rate was in a range of 1.14–1.64 and varied with the gas fluxes. In consideration of potential applications of the proposed PDMS etching method, array-type PDMS microwells and network-type microprotrusion structures were fabricated. The contact angle was dramatically increased from 104° (non-etched PDMS surface) to 148° (etched PDMS surface) and the surface was thereby modified to be superhydrophobic. In addition, a thin PDMS skin that blocked holes and PDMS residues affixed in nickel microstructures was successively removed.</P>

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

Exploring the Impacts of Consumers’ Systematic and Intuitive Cognitive Styles on Their Visual Attention Patterns in Online Shopping Environments: Emphasis on Eye-Tracking Method

Yoon Min Hwang1,Kun Chang Lee 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.12

We are living in a hypercompetitive market. Therefore, companies running online shopping malls must muster their wisdom to make online shopping websites one of their strategic assets. To meet this objective, companies should understand online consumers’ cognitive styles, and then design their online websites according to the styles. In this sense, we focus on two cognitive styles such as systematic type and intuitive type. The former means that consumers may pay more attention to reasonable statements about target product before making decisions, while the latter indicates that consumers may react more sensitively to intuitive information such as images and abstract conjecture. For the sake of novel approach to conducting experiments, we adopted an eye-tracking approach which we believe is more reliable in providing relevant information capable of answering our research questions. For the utilitarian product like notebook computer, systematic type users may show higher TFD (Total Fixation Duration) and FC (Fixation Count) to consumer reviews than intuitive type users. Also, intuitive type users may be more sensitive to special purchase opportunity-giving events information with higher TFD and FC than systematic type users. Through our experiments with an eye-tracking method, we could conclude that a strategic redesign of the online shopping websites is necessary where consumers' cognitive styles need to be significantly considered.

Au 전극의 DDT 보호막 처리 및 그 전기적 효과와 응용

최민수(Min-Su Choi),이동진(Dong-Jin Lee),김태근(Tae-Gun Kim),황성우(Sung-Woo Hwang) 대한전기학회 2010 전기학회논문지 Vol.59 No.1

We report the passivation characteristics of dodecanethiol (DDT) molecules on gold electrodes of field effect transistor bio-sensors. The leakage current between the electrolyte and the electrode can be as small as 3pA when 7 mM of DDT passivation is performed. The DDT layer is also shown to resist the attack of acid up to 120 mins.

두개안면 섬유성 이형성증의 임상적 고찰

백롱민,오갑성,윤성호,백세민,황민호 大韓成形外科學會 1994 Archives of Plastic Surgery Vol.21 No.3

Fibrous dysplasia is a benign pathologic condition of bone and causes facial deformities as well as functional problems. We have managed 32 craniofacial fibrous dysplasia form March 1989 to December 1993. The most common age distribution of surgery was second decade(34%) and third decade(53%). In our patients, the desease process usually begins in childhood and progresses throughout puberty and adolescence. Treatment was aimed at preventing and correcting functional problems and achieving normal facial aesthetics. The reconstruction with other combined surgery, i.e., mandibular and maxillary osteotomies, reduction malar plasty, malar augmentation and orbit, nasal reconstruction with bone graft. Postoperative results were satisfactory in most cases. In some patients, repeated contouring(16%) surgery might produce less morbidity than a single massive resection. In evaluating the extent of the lesion, computerized tomography prooved to be a good diagnostic tool. Aethetically and functionally satisfactory surgical results were achieved by bone shaving in combination with reconstructive surgery.

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).

Microfluidic generation of Prussian blue-laden magnetic micro-adsorbents for cesium removal

Kang, Sung-Min,Rethinasabapathy, Muruganantham,Hwang, Seung Kuy,Lee, Go-Woon,Jang, Sung-Chan,Kwak, Cheol Hwan,Choe, Sang-Rak,Huh, Yun Suk Elsevier 2018 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.341 No.-

<P><B>Abstract</B></P> <P>Here, we designed and synthesized a recoverable multifunctional adsorbent using a microfluidic reaction system and evaluated the removal performance of the smart adsorbent toward radioactive cesium as a model sample. Prussian blue-laden magnetic micro-adsorbents (PB-MNPs-MAs) with uniform morphology and monodispersity were generated via two-step sequential procedures using a glass capillary microfluidic system, followed by chemical co-precipitation with a high production rate. The cesium removal efficacy of the PB-MNPs-MAs was analyzed based on Langmuir and Freundlich isotherms by controlling adsorption parameters such as adsorbent size, initial cesium concentration, and contact time. The adsorption isotherm of the PB-MNPs-MAs was better fitted to the Langmuir model with a maximum cesium adsorption capacity of 58.73 mg g<SUP>−1</SUP>, which was 40% higher than that of macro-adsorbents in a dynamic magnetic field. This result can be attributed to their large specific area, which increased the kinetic rate of cesium adsorption and achieved saturation within 20 min. Additionally, the PB-MNPs-MAs were recovered from wastewater within 5 s under a static magnetic field, indicating their great potential for magnetic actuation. We believe that our PB-MNPs-MAs can encapsulate nano-functional adsorbents and prevent actuation, making them promising for environmental remediation and especially for removal of radionuclides.</P> <P><B>Highlights</B></P> <P> <UL> <LI> PB-MNPs-MAs were generated in microfluidic device using chemical co-precipitation. </LI> <LI> The prepared PB-MNPs-MAs are monodispersed with uniform morphology. </LI> <LI> PB-MNPs-MAs exhibited high Cs adsorption capacity (58.73 mg g<SUP>−1</SUP>). </LI> <LI> 100% recovery of PB-MNPs-MAs is possible under static magnetic field after Cs adsorption. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Nanocrystalline silicon films deposited with a modulated hydrogen dilution ratio by catalytic CVD at 200 ℃

Tae-Hwan Kim,Kyoung-Min Lee,Jae-dam Hwang,Wan-Shick Hong 한국물리학회 2009 Current Applied Physics Vol.9 No.2

Nanocrystalline silicon (nc-Si) thin films that are deposited at low-temperatures (<200 ℃) often contain an incubation layer as thick as 10 nm. This incubation layer deteriorates performance of electronic devices, such as bottom-gate thin-film transistors, fabricated from the nc-Si film. We found that the crystallinity of the nc-Si films could be improved by adding a large quantity of hydrogen to the source gas. However, the hydrogen dilution degraded the deposition rate. We attempted a modulation of the hydrogen dilution ratio in a catalytic chemical vapor deposition (Cat-CVD) system to achieve both a minimal incubation layer and high throughput. We obtained an incubation-layer thickness of 3 nm and were able to grow a 200-nm-thick film in 18 min. Nanocrystalline silicon (nc-Si) thin films that are deposited at low-temperatures (<200 ℃) often contain an incubation layer as thick as 10 nm. This incubation layer deteriorates performance of electronic devices, such as bottom-gate thin-film transistors, fabricated from the nc-Si film. We found that the crystallinity of the nc-Si films could be improved by adding a large quantity of hydrogen to the source gas. However, the hydrogen dilution degraded the deposition rate. We attempted a modulation of the hydrogen dilution ratio in a catalytic chemical vapor deposition (Cat-CVD) system to achieve both a minimal incubation layer and high throughput. We obtained an incubation-layer thickness of 3 nm and were able to grow a 200-nm-thick film in 18 min.