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>

흰쥐의 중추성 Serotonin 고갈이 강제수영 중 부동자세 시간, 불안 및 수동적 회피 학습에 미치는 효과

박제민,김종백,강철중 大韓神經精神醫學會 1996 신경정신의학 Vol.35 No.3

흰쥐에서 p-chlorphenylalanine(PCPA)로 인한 강제수영 중 부동자세 시간의 단축이 불안이나 수동적 회피 학습 능력의 변화와 관련된 것인가를 검증하고자 하였다. 흰쥐에게 PCPA 300mg/kg 혹은 생리식염수를 하루 한 번 연속 3회 복강내 주사하였다. 마지막 주사 24시간 후에 공간에서의 활동성(ACT0), 높은 십자 통로 실험에서 개방 통로에 머무는 시간(ANX0), 왕복 회피상자에서 통과 지연 시간(STL0) 등을 측정하고 0.5mA 전기자극을 3초간 주어 회피 반응을 학습시켰다. 그리고 15분간 강제수영시켰다. 다음 날 같은 방법으로 활동성(ACT1), 불안(ANX1), 수동적 회피 반응 학습 정도(STL1), 5분간의 강제수영 중 총 부동 자세 시간 등을 측정하였다. 마지막 약물 혹은 대조액 투여 7일 후 수동적 회피 학습 유지 정도(STL7)를 다시 측정하였다. 결과는 아래와 같다. 1) 전체 대상군에서 ACT1은 ACT0보다 감소하였다. PCPA는 개방공간에서의 활동성에 영향을 주지 않았다. 2) PCPA 군은 높은 십자 통로 실험에서 ANX0와 ANX1 둘 다 대조군 보다 유의하게 길었다. 3) STL1은 PCPA군과 대조군 모두 STL0 보다 유의하게 지연되었다. PCPA는 STL0 이나 STL1에 영향을 주지 않았다. 그러나 대조군은 수동적 회피 학습 7일 후에도 통과 지연 시간이 유의하게 연장되어 있는데 반하여 PCPA군은 STL7이 STL0과 유의한 차이가 없었다. 4) 강제수영 중 부동자세 시간은 PCPA군이 대조군보다 유의하게 짧았다. 이상의 결과에서 PCPA 투여로 인한 강제수영 중 부동자세 시간의 단축은 PCPA가 비특이적 신체 활동을 증가시키거나 수동적 회피 반응 습득을 방해함으로써 일어나는 현상이 아니며, 진정 작용없이 탐색 행동을 증가시키거나, 스트레스 하에서의 행동 억제 현상을 차단함으로써 강제수영 중 부동자세 시간을 단축시킨다고 추론한다. 아울러 PCPA가 기억 고정 과정을 방해할 가능성이 있음을 제안한다. Purpose : The test if p-chlorophenylalanine(PCPA) induced decrease of immobility time during forced swimming test in rats is an epiphenomenon related with PCPA-induced changes in anxiety level or learning ability. Methods : 22 male rats(Sprague Dawley, weighting 180-280gm) were randomly assigned to PCPA or control group and treated with 300mg/kg of PCPA or saline i.p. at -72, -48, and -24 hrs. Number of segment(ACT0) entered with 4 limbs on the open field(L100×W100×H40cm, 25 segments), time(ANX0, sec) spent on the open arm(L110×W10cm, 50cm from the ground) in the elevated plus maze, and step-through latency(STL0, cut-off time : 300sec) in the shuttle box(L76.2×W34.3×H50.8cm, 7.5w electric bulb in the light chamber, 0.5mA for 3 sec in the dark chamber) were measured consequently at 24hrs after the last injection of PCPA or saline. After 20min of rest, animals were forced to swim for 15 min(cylinder : φ18×H40cm ; water : H15cm, 25℃). On the next day, the second trial of open field test(ACT1), elevated plus maze test(ANX1), passive avoidance learning test(STL1), and measurement of total immobility time(IT, sec) during the 5min of forced swim were done in the same manner as the first trial except that electrical shock was not given to the animals in the passive avoidance learning test and duration of forced swimming was shortened from 15min to 5min. To evaluate longterm effect of PCPA on maintenance of memory, measurement of step-through latency was repeated 7 days after the first trial(STL7). Result: 1) ACT1 was significantly decreased in the pooled sample, but the effect of PCPA on the general motor activity was not significant. 2) PCPA significantly prolonged the time spent on the open arms in the elevated plus maze test. 3) Comparing to STL0, STL1 was significantly prolonged in both groups. PCPA did not affect STL0 or STL1. STL7 was significantly prolonged in the control group, but not in the PCPA group. 4) PCPA shortened IT significantly. Conclusion : PCPA-induced decrease of immobility time during the forced swimming test in rats seems to be related with disinhibition of stress-related behavioral suppression. PCPA does not affect acquisition and short-term maintenance of passive avoidance learning, but necessity of further studies about its effect on long-term maintenance on memory is raised.

폐경전 여성에서 에스트로겐 수용체 유전자 다형성과 골초음파 지표의 상관관계에 대한 연구

김정순,정동진,강혜숙,강세훈,김경민,홍세인,조동혁,강호철,정민영 全南大醫大 2004 전남의대학술지 Vol.40 No.1

갑상선 기능항진증 환자에서 인슐린감수성 및 인슐린분비능의 변화

최은진,강호철,이태희,정민영,이대호,장연진,박상선,조재현 대한내분비학회 1994 Endocrinology and metabolism Vol.9 No.2

The impairement of glucose metabolism is frequently associated in hyperthyroidism. The present study was performed to determine the effect of the thyroid hormone excess on insulin sensitivity and on insulin secretory function in vivo. Ten newly diagnosed hyperthyroid patients and fifteen healthy control subjects were subjected to frequently sampled intravenous glucose tolerance tests(FSIGT) after an overnight fast. Insulin sensitivity, represented by the insulin sensitivity index(S_1), was assessed by minimal model analysis of FSIGT data. Insulin secretion was measured by the total area under the insulin curve after glucose load. The results were as follows. 1) The K_G values, which represent glucose tolerance, were not different between the hyperthyroid patients and the normals(2.2+-0.3 vs. 2.5+-0.3%/min, p$gt;0.05). 2) S_1 was significantly decreased in the hyperthyroid patients in comparison to the normals(7.5+-1.4 vs. 2.6+-0.3X10^-4 min^-1/uU/ml, p$lt;0.05). 3) The basal insulin concentration was higher in the hyperthyroid patients than in the normals(8.3+-2.4 vs. 4.6+-0.4 uU/ml, p=0.07). In addition, the insulin secretory response to a glucose load was increased in the hyperthyroid patients as evidenced by the peak plasma insulin level(168.2+-30.4 vs. 89.2+-13.9 uU/ml, p$lt;0.05) and by the total area under the insulin curve(2641.1+-443.2 vs. 1696.7+-204.3 min uU/ml, p$lt;0.05). These results clearly demonstrated that insulin sensitivity was impaired in these newly diagnosed hyperthyroid patients. However, glucose tolerance was maintained by the increased insulin secretion (J Kor Soc Endocrinol 9:108-114, 1994).

단신 : 실리콘의 염소화반응에 의한 사염화규소 제조

박균영 ( Kyun Young Park ),이미선 ( Mi Sun Lee ),김민철 ( Min Cheol Kim ),이찬희 ( Chan Hee Lee ),박회경 ( Hoey Kyung Park ),강태원 ( Tae Won Kang ),정해성 ( Hae Seong Jeong ),한경아 ( Kyoung Ah Han ),허원회 ( Weon Hoe Huh ),유지 한국화학공학회 2013 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.51 No.3

직경 25 mm의 파이렉스 튜브 내에서 실리콘의 유동층 염소화 반응이 수행되었다. 반응기에 공급되는 질소 유량0.8~1.0 L/min, 염소 유량 0.2 L/min, 반응온도 450℃, SiCl4 응축기의 냉매온도는 -5℃로 설정하였다. 반응기에 도입되는 가스 내 염소의 몰분율이 증가하면 SiCl4의 수율이 증가하였다. 반응가스 중 염소의 몰분율 0.2의 조건에서 SiCl4의 수율은 28% 이었다. 염소의 몰분율 증가는 반응열 상승에 의해 반응온도 상승을 가져옴으로써 안전을 고려하여 염소의 몰분율을 0.2 이상으로 올리지 못했다. 실리콘의 유동층 염소화 반응에 의한 사염화실리콘의 제조 가능성이 입증되 었으며, 향후 보다 가혹한 조건에서의 실용화 연구를 위한 기초로 활용될 수 있을 것으로 기대된다. The chlorination of a metallurgical-grade silicon was carried out in a fluidized bed reactor, 25 mm in diameter. The flow rate of the chlorine admitted into the reactor was 0.2 L/min and that of the carrier nitrogen was 0.8~1.0 L/ min. The reactor temperature was maintained at 450℃ and the temperature of the coolant at the SiCl4 condenser was at -5℃. The SiCl4 yield increased with increasing the mole fraction of chlorine in the feed gas, exhibiting 28% at the mole fraction of 0.2. Further increase of the chlorine mole fraction was not attempted in a worry that the reactor might be failed due to the high exothermicity of the reaction. The production of SiCl4 from silicon by fluidized bed chlorination was demonstrated on a laboratory scale, which is a stepping stone for future studies under more severe conditions toward industrial application.

The effects of secondary task on the control of vehicle under driving simulator: a study among 50s taxi drivers

Han Soo Kim,Jin Seung Choi,Dong Won Kang,Hong Won Yeon,Mi Hyun Choi,Doo Hwan Ji,Byung Chan Min,Soon Cheol Chung,Gye Rae Tack 대한인간공학회 2011 대한인간공학회 학술대회논문집 Vol.2011 No.5

Objective: The aim of this study is to quantitatively evaluate the effects of the secondary task during simulated driving using the variable indicating control of vehicle. Background: There are so many researches for simulated driving and performance. For instance, some researches show that the effects of cell phone conversations on simulated driving. Cell phone conversations impaired explicit recognition memory. Method: Participants included 50s taxi drivers; 15 males and 15 females. All subjects were instructed to keep a distance (30m) from the car ahead and a constant speed (80km/hr or 100km/hr). Sending text message (STM) and Searching navigation (SN) were selected as the secondary task. Experiment consisted of rest for 3min., driving alone for 1min. and driving with secondary task for 1 min.. We were analyzed anterior-posterior coefficient of variation (APCV) and medial-lateral coefficient of variation (MLCV). Results: APCV was increased by 175.4% in STM and 223.8% in SN at 80km/hr. MLCV was increased by 242.3% in STM and 323.4% in SN at 100km/hr. There was no significant difference between genders. Conclusion: Consequently, performing secondary task during driving impaired the control of vehicle.

Lactobacillus pentosus 발효에 의한 담쟁이덩굴 줄기 추출물의 항산화 및 세포보호 효과

박소현 ( So Hyun Park ),성준섭 ( Joon Seob Seong ),이건수 ( Keon Soo Lee ),박영민 ( Young Min Park ),현송화 ( Song Hua Xuan ),차미연 ( Mi Yeon Cha ),강희철 ( Hee Cheol Kang ),박수남 ( Soo Nam Park ) 대한화장품학회 2017 대한화장품학회지 Vol.43 No.3

본 연구에서는 담쟁이덩굴 줄기 70% 에탄올 추출물과 발효균주 Lactobacillus pentosus를 이용하여 발효시킨 담쟁이덩굴 줄기 발효추출물에 대하여 항산화 및 세포보호 효과를 측정하였다. 1,1-Diphenyl-2-picrylhydrazyl (DPPH)를 이용한 자유라디칼 소거 활성(FSC₅₀)은 담쟁이덩굴 줄기 추출물 및 발효추출물이 각각 42.3 및 34.5 μ g/mL로 발효 후의 라디칼 소거활성이 약 18.4% 더 높게 나타났다. Lumiol-의존성 화학발광법을 이용한 Fe³⁺-EDTA/H₂O₂계에서의 총 항산화능(OSC₅₀) 평가에서도 담쟁이덩굴 줄기 추출물과 발효추출물은 각각 2.6 및 2.5 μ g/mL로 발효 후가 약 4.2% 정도 더 높은 총 항산화능을 나타냈다. ¹O₂로 유도된 적혈구 세포손상에 있어서 추출물 및 발효추출물의 세포 보호 효과(τ₅₀)는 50 μ g/mL에서 각각 126.4 및 173.0 min을 나타내어 발효 후 세포 보호 효과가 약 34.0% 더 높게 나타났다. 발효추출물은 지용성 항산화제로 알려진 (+)-α-tocopherol (43.4 min)보다도 3.9배 높은 세포 보호 활성을 보여주었다. 사람 섬유아세포인 Hs68을 대상으로 elastase 저해 활성을 조사하였다. Elastase 저해 활성(IC₅₀)은 담쟁이덩굴 줄기 추출물과 발효추출물에서 각각 873.6 및 687.8 μ g/mL로 발효 후에 elastase 저해 활성이 약 21.3% 더 높은 것으로 나타났다. 이상의 결과들은 담쟁이덩굴 줄기 발효추출물이 항산화 작용과 더불어 주름개선 효과를 가지는 천연 화장품 소재로써 응용 가능성이 있음을 시사한다. In this study, the antioxidant activities, cellular protective effects, and inhibitory effects on elastase of non-fermented and fermented extracts of Parthenocissus tricuspidata (P. tricuspidata) stem using Lactobacillus pentosus were investigated. The free radical scavenging activities (FSC₅₀) of non-fermented and fermented extracts were 42.3 and 34.5 μg/mL, respectively, in which the activity after fermentation was approximately 18.4% higher. Reactive oxygen species (ROS) scavenging activities (OSC₅₀) in Fe³⁺-EDTA/H₂O₂ system of non-fermented and fermented extracts were 2.6 and 2.5 μg/mL, respectively. The activity after fermentation was approximately 4.2% higher. In the ¹O₂-induced cellular damage of erythrocytes, the cellular protective effects (τ₅₀) of non-fermented and fermented extracts were 126.4 and 173.0 min at 50 μg/mL, respectively. The activity after fermentation was approximately 34.0% higher. The effect of fermented extract was 3.9 times higher than (+)-α-tocopherol (τ₅₀ = 43.4 min), known as a lipophilic antioxidant at 50 μg/mL. The inhibitory effect of elastase was investigated to predict the anti-wrinkle efficacy using Hs68 human fibroblasts cells. The elastase inhibitory activities (IC₅₀) of non-fermented and fermented extracts were 873.6 and 687.8 μg/mL, respectively, and the activity after fermentation was approximately 21.3% higher. These results indicated that fermented extract of P. tricuspidata stem has potentials as natural cosmetic ingredients with antioxidant and anti-wrinkle effect.

마그네슘 성형기술의 최근 동향

강민철,예대희,손근용 한국주조공학회 2003 한국주조공학회지 Vol.23 No.6

Vacor의 약동학적 연구

강철민,이민화,이기영,이민화 全南大醫大 1993 전남의대학술지 Vol.30 No.1

중공유리구에 고정화된 TiO_2 광촉매를 이용한 수중 조류(藻類)의 광합성억제

강민수,정익상,조인철,김성우,이동근 경상대학교 환경보전연구소 2000 環境保全硏究所報 Vol.8 No.-

TiO_2 was coated on the surface of the hollow pyrex glass beads through a sol-gel method. The TiO_2-coated hollow glass bead was employed as a photocatalyst to inactivate the algae under the illumination of UV light. TiO_2 could successfully be immobilized as a film on the surface of the glass bead. The TiO_2 film had anatase form and the average thickness of the film was estimated to be 0.3㎛. Two species of algae. Anabaena, and Microcystis were taken for the inactivation experiments. They are commonly found in algal blooms in eutrophic waters. When irradiated by UV light in the presence of the TiO_2-coated glass beads. Anabaena cells and Microcystis cells were lost their photosynthetic activity. Complete photocatalytic inactivation of Anabaena and Microcystis was obtained in about 30min.