Induction of heme oxygenase-1 protects against podocyte apoptosis under diabetic conditions

Lee, Sang Choel,Han, Seung Hyeok,Li, Jin Ji,Lee, Sun Ha,Jung, Dong-Sub,Kwak, Seung-Jae,Kim, Seung Hye,Kim, Dong Ki,Yoo, Tae-Hyun,Kim, Jin Hyun,Chang, Se-Ho,Han, Dae Suk,Kang, Shin-Wook International Society of Nephrology 2009 Kidney international Vol.76 No.8

Heme oxygenase-1 (HO-1) is an anti-oxidant enzyme normally upregulated in response to oxidant injury. Here we determined the role of HO-1 in podocyte apoptosis in glomeruli of streptozotocin-treated rats and in immortalized mouse podocytes cultured in media containing normal or high glucose. HO-1 expression, its activity, the ratio of Bax/Bcl-2 protein, and active caspase-3 fragments were all significantly higher in isolated glomeruli of diabetic rats and in high glucose–treated podocytes. These increases were inhibited by zinc protoporphyrin treatment of the rats or by HO-1 siRNA treatment of the podocytes in culture. The number of apoptotic cells was also significantly increased in the glomeruli of diabetic rats and in high glucose–treated podocytes. Inhibition of HO-1 accentuated the increase in apoptotic cells both in vivo and in vitro. Our findings suggest that HO-1 expression protects against podocyte apoptosis under diabetic conditions.

ESPI를 이용한 충격손상을 받은 복합재료 내부결함의 정량평가

김경석,양광영,장호섭,지창준,윤홍석 한국공작기계학회 2003 한국공작기계학회 추계학술대회논문집 Vol.2003 No.-

Electronic Speckle Pattern Interferometry for quantitative evaluation of a impact defect inside of composite material plate are described. The impact on composite material makes inside delamination which is difficult to detect visual inspection and ultrasonic testing due to non-homeogenous structure. This paper proposes the quantitative evaluation technique of defects under real impact. Artificial defects are designed inside of composite plate for development of inspection technique and real defects under impact are inspected and compared with results of visual inspection.

하천 복원을 위한 과거 및 현재 자료 기반의 하천지형학적 특성 분석: 미호천과 내성천을 중심으로

이찬주,김지성,김규호,신형섭,Lee, Chan Joo,Kim, Ji Sung,Kim, Kyu Ho,Shin, Hyoung Sub 한국수자원학회 2015 한국수자원학회논문집 Vol.48 No.3

하천 복원을 위한 기초 작업으로서 자연 상태에 가까운 하천의 지형학적 특성을 파악하기 위해 과거 및 현재 자료를 이용하여 하천지형학적 분석을 실시하였다. 대상 하천은 미호천과 내성천이다. 분석에 포함된 지형학적 변수는 하곡변수인 곡저폭, 하도 형상변수인 사행도, 강턱하폭, 하도경사, 구성재료 변수인 하상재료, 지배 변수인 강턱유량, 비유수력이며, 지배적인 프로세스가 함께 고려되었다. 분석 결과 두 하천은 비슷한 유역면적을 갖는 모래하천이지만, 곡저폭, 하도 형상변수, 종단적 위치에 따른 지배적인 프로세스 등에서 차이가 있는 것으로 나타났다. 또한 지형학적 변수들 사이의 상호 관계를 분석하였다. 그 결과 강턱하폭은 강턱유량에 비례하여 증가하였고, 그 경향성은 기존의 연구 결과와 대체로 일치하고 있다. 강턱유량과 하도경사를 분석한 결과 미호천은 사행하천과 망상하천의 특성을 나타내고 있는 반면, 내성천은 대부분의 구간에서 망상하천에 해당하는 것으로 나타났다. 하도경사와 하폭수심비 관계를 이용하여 지배적인 프로세스를 분석한 결과 미호천은 사구-연흔의 특성을 나타내고 있으나 내성천은 하류에서는 망상하천 특성이 지배적인 반면, 상류에서는 여울-소 내지는 평하상 특성이 지배적인 것으로 나타났다. 과거 자료를 이용한 분석 결과는 정비된 하천의 자료를 이용한 분석 결과에 비해 합리적인 것으로 나타났다. As a basic work for river restoration, analysis on fluvial geomorphological characteristics is made using past and present data to understand close-to-nature geomorphic status. The Miho and the Naesung Rivers are targets of this study. Fluvial geomorphic variables including valley-floor width, sinuosity, bankfull width, channel gradient, bed material size, bankfull discharge and unit stream power are evaluated with dominant processes. Though common sand-bed rivers with similar catchment area, the Miho and the Naesung Rivers are different in terms of valley-floor width, channel shape variables and dominant processes related with longitudinal location. In addition, analyses on interrelationship among the geomorphological variables are carried. Bankfull width is shown to be proportional to bankfull discharge, as is in a rough agreement with the previous studies. Relationship of bankfull discharge and channel gradient shows meandering and braiding are prevalent in the Miho River, whereas the most of the sub-reaches of the Naesung River fall to braiding. Relationship of channel gradient with width-depth ratio indicates dune-ripple processes are dominant in the Miho River, while the Naesung River shows longitudinal diversity from braiding in the downstream sub-reaches to riffle-pool and plane-bed along the upper ones. Analyses based on the past data on a river in a close-to-nature status are thought to be rather reasonable in comparison with those on the same river in a engineered condition.

The effect of energetically coated ZrO_x on enhanced electrochemical performances of Li(Ni_1/3Co_1/3Mn_1/3)O₂ cathodes using modified radio frequency (RF) sputtering

Lee, Ji-Hoon,Kim, Ji Woo,Kang, Ho-Young,Kim, Seul Cham,Han, Sang Sub,Oh, Kyu Hwan,Lee, Se-Hee,Joo, Young-Chang The Royal Society of Chemistry 2015 Journal of materials chemistry. A, Materials for e Vol.3 No.24

<▼1><P>By introducing the ZrOx layer coated using a novel sputtering, the electrochemical performance of Li(Ni1/3Co1/3Mn1/3)O2 under liquid and solid electrolyte was greatly improved.</P></▼1><▼2><P>To date, most coating layers for electrode materials for Li-ion batteries have been fabricated using the sol–gel method or atomic layer deposition (ALD), which involve complicated processing steps and limited candidates for coating materials. With an emphasis on solving these issues, herein, a new coating methodology based on a sputtering system was developed, and sputtered zirconium oxide was coated on Li(Ni1/3Co1/3Mn1/3)O2 (L333) cathode powders. The continuous movement of the cathode powders during the coating procedure and the high kinetic energy from the sputtering process resulted in a highly uniform coating layer with multiple structures exhibiting a concentration and valence state gradient of Zr, <I>i.e.</I>, surface (mainly Zr<SUP>4+</SUP>) and doped (mainly Zr<SUP>2+</SUP>) layers. The ZrOx-coated L333 powders exhibited an outstanding capacity retention (96.3% at the 200th cycle) and superior rate capability compared with the uncoated version in a coin cell with 1 M LiPF6 in EC : DEC liquid electrolyte. The ZrOx-coated L333 powders also exhibited an enhanced specific capacity in a solid state battery cell with a sulfide-based inorganic solid-state electrolyte. The improved electrochemical performance of ZrOx/L333 was attributed to the synergetic effect from the surface and doped layers: physical/chemical protection of the active material surface, enhancement of Li-ion diffusion kinetics, and stabilization of the interfaces.</P></▼2>

CaCl₂ 용융염에서 TiO₂ 펠렛의 전기화학적 환원반응 특성

지현섭,류효열,정하명,정광호,정상문,Ji, Hyun-Sub,Ryu, Hyo-Yeol,Jeong, Ha-Myung,Jeong, Kwang-Ho,Jeong, Sang-Mun 한국방사성폐기물학회 2012 방사성폐기물학회지 Vol.10 No.2

본 연구에서는 $850^{\circ}C$의 $CaCl_2$ 용융염계에서 전해환원공정을 통해 $TiO_2$로부터 금속티타늄을 제조하였다. Ni-$TiO_2$ 조합전극을 환원전극으로 그라파이트를 산화전극으로 사용하였으며, 셀전위를 제어하면서 $TiO_2$의 전해환원 특성을 관찰하였다. XRD 분석을 통해 $TiO_2$가 $CaTiO_3$, $Ti_2O$, $Ti_6O$와 같은 다양한 반응 중간생성물을 거쳐 Ti 스폰지로 환원되는 것이 밝혀졌다. 또한 SEM 분석을 통해 $TiO_2$ 전해환원 반응동안 펠렛의 바깥표면부터 환원반응이 시작되어 펠렛중심으로 진행이 되는 것이 확인되었다. 전해환원 반응도중 환원된 티타늄금속은 초기에는 다공성 스폰지 구조를 보이나 고온에서 반응이 진행됨에 따라 점차 소결에 의해 수축되어 다공성 구조가 사라지는 현상을 보였다. A porous $TiO_2$ pellet was electrochemically converted to the metallic titanium by using a $CaCl_2$ molten salt system at $850^{\circ}C$. Ni-$TiO_2$ and graphite electrodes were used as cathode and anode, respectively. The electrochemical behaviour of $TiO_2$ pellet was determined by a constant voltage control electrolysis. Various reaction intermediates such as $CaTiO_3$, $Ti_2O$ and $Ti_6O$ were observed by XRD analysis during electrolysis of the pellet. Once $TiO_2$ pellet was converted to a porous metallic structure, the porous structure disappeared by sintering and shrinking with increasing the reaction time at high temperature.

저온 초음파 추출에 의한 Spirulina maxima 면역활성 증진

오성호(Sung Ho Oh),한재건(Jae Gun Han),하지혜(Ji Hye Ha),김영(Young Kim),정명훈(Myoung Hoon Jeong),김승섭(Seong Sub Kim),정향숙(Hyang Suk Jeong),최근표(Geun Pyo Choi),박욱연(Uk Yeon Park),강도형(Do Hyung Kang),이현용(Hyeon Yong Lee) 한국식품과학회 2009 한국식품과학회지 Vol.41 No.3

본 실험은 해수에서 배양된 Spirulina maxima를 100℃와 초음파 병행 60℃ 물 추출물, 80℃ EtOH 추출물을 이용하여 실험을 수행하였다. AOAC법에 의한 일반 조성 및 무기질, 아미노산 조성 분석결과 조 단백질과 무기질 중 나트륨이 각각 56, 60%의 비교적 높은 비율을 차지했으며, 다양한 균주의 필수 아미노산을 포함하고 있었다. 그중 피부와 관련된 leucine의 함량이 9.83%로 상대적으로 풍부하여 S. maxima 피부면역 활성 증진에 효율적인 소재의 가능성을 확인했다. 본 연구에서는 피부 면역과 인체 면역과의 밀접한 상관성이 있으므로 본 연구에서는 T 세포와 B 세포의 생육증진 및 cytokine의 분비량 측정과 NK 세포의 활성 및 항염증 효과인 hyaluronidase 저해 활성 효과를 측정하였다. 먼저 정상세포(HEK293)에 대한 세포독성 결과 인체에 큰 독성을 나타내지 않는 것으로 나타난 S. maxima를 추출조건에 따른 면역증진 효과를 비교한 결과 60℃ 초음파 병행 물 추출물이 면역 B세포와 T세포에서 각각 11.3×10sub{4} cells/mL, 12.8×10sub{4} cells/mL으로 6일째 가장 높은 생육도를 보였다, 이러한 면역 세포들이 분비하는 cytokine(IL-6, TNF-α)의 분비량은 가장 높은 생육도를 보인 60℃ 초음파 병행 물 추출물을 첨가한 B세포, T세포의 경우 IL-6와 TNF-α는 유의적으로 증가된 분비량을 보이며, 면역 및 기능성 소재로서의 활성이 뛰어난 것으로 나타났다. B세포에 각 시료를 첨가하여 배양 후 그 배양액을 NK 세포에 첨가하였을 때, 6일 동안 생육도를 관찰하였는데 시료에 대한 생육도가 증가하며, 6일째 12.40×10sub{4} cells/mL를 나타내어 11.49×10sub{4} cells/mL를 나타낸 대조군에 비해 높은 활성을 나타내었으며, 이로써 활성물질을 포함하고 있음을 알 수 있다. 또한 항염증 효과의 hyaluronidase 저해 활성 효과에서 60℃ 초음파 병행 물 추출물이 1.0mg/mL 농도일 때 62.4%의 저해 활성을 보여 100℃ 이상의 고온 추출에서 야기되는 단백질이나 미립자 활성 물질의 파괴가 최소화되고 저온 초음파 추출 시 유용성분들의 용출량 증가와 새로운 물질들의 생산 혹은 활성변형에 의한 추출을 통해 인체면역과 피부면역 활성 증진에 활용이 가능한 효율적인 소재화가 가능한 것을 확인했다. 이로써, 본 연구 논문은 S. maxima의 물질 분리보다 피부면역관련 활성을 통한 소재로서의 탐색이 주목적이므로 향후 이 추출물의 분리, 동정을 통해 피부 면역 활성도에 따라 물질의 구조 분석에 관한 연구를 보이고자 한다. The marine microalga Spirulina maxima was extracted using water or ethanol at 100 or 80℃ and by ultrasonification in water at 60℃. The ultrasonification technique generated the highest yield (19.8%). To be therapeutically useful, the extraction should yield a product with low cytotoxicity and high immunity against skin infections. The cytotoxicity of all extracts (1.0 mg/mL) was below 25%. Moreover, the cytotoxicity of the extract generated by ultrasonification was 5%. Extracts prepared in the described manners could inhibit hyaluronidase activity by up to 40% compared to the control. Increased growth of human B, T and NK cells and an increase in cytokine secretion were observed, confirming the interrelationship between both human immune and skin immune activity. The extract prepared by ultrasonification increased the growth of human B, T and NK cells up to 10.3×10sub{4} cells/mL, 11.3×10sub{4} cells/mL and 19.1×10sub{4} cells/mL, respectively. The extract prepared by ultrasonification also greatly increased the secretion of both IL-6 and TNF-α. Moreover, it was estimated that protein, Na and leucine occupy a high ratio. Accordingly, this study has confirmed that extracts prepared as described have the potential to effectively increase skin immunity.

Study on Ginseng Protopanaxadiol and Protopanaxatriol Saponins- Induced Antinociception

Young-Hee Shin,Seok-Chang Kim<SUB>,<.SUB>Ji-Won Han,Dae-Hoon Kim,Sang-Sub Han,Dong-Ho Shin,Seung-Yeol Nah 대한생리학회-대한약리학회 1997 The Korean Journal of Physiology & Pharmacology Vol.1 No.2

<P> We studied the effects of ginseng protopanaxadiol (PD) and protopanaxatriol (PT) saponins on the analgesia using several pain tests such as writhing, formalin, and tail-flick test. Using mouse, pretreatment of PD or PT saponins (i.p.) induced inhibition of abdominal constrictions caused by 0.9% acetic acid administration(i.p.). The AD<SUB>50</SUB> was around 27 (17-43) mg/kg for PD and 13.5 (3-61) mg/kg for PT saponins in writhing test. Both PD and PT saponins also showed the inhibition of bitings and lickings of hindpaw after administration of 1% formalin. In particular, both PD and PT saponins showed analgesic effects on second phase of pain. The AD<SUB>50</SUB> was 44.5 (26-76) mg/kg for PD and 105 (55-200) mg/kg for PT saponins in second phase of formalin test. For first phase pain inhibition by PD or PT saponins, they were required higher concentrations. However, PD saponins showed weak analgesic effects in tail-flick test with high concentration. In conclusion, we found that both PD and PT saponins have the analgesic effects in writhing test and second phase of pain in formalin test. These results suggest that both PD and PT saponins inhibit neurogenic or tonic pain rather than acute pain.

Pyruvate Kinase M2 : A Novel Biomarker for the Early Detection of Acute Kidney Injury

Ji Hyun Cheon,Sun Young Kim,Ji Yeon Son,Ye Rim Kang,Ji Hye An,Ji Hoon Kwon,Ho Sub Song,Aree Moon,Byung Mu Lee,Hyung Sik Kim 한국독성학회 2016 Toxicological Research Vol.32 No.1

The identification of biomarkers for the early detection of acute kidney injury (AKI) is clinically important Acute kidney injury (AKI) in critically ill patients is closely associated with increased morbidity and mortality. Conventional biomarkers, such as serum creatinine (SCr) and blood urea nitrogen (BUN), are frequently used to diagnose AKI. However, these biomarkers increase only after significant structural damage has occurred. Recent efforts have focused on identification and validation of new noninvasive biomarkers for the early detection of AKI, prior to extensive structural damage. Furthermore, AKI biomarkers can provide valuable insight into the molecular mechanisms of this complex and heterogeneous disease. Our previous study suggested that pyruvate kinase M2 (PKM2), which is excreted in the urine, is a sensitive biomarker for nephrotoxicity. To appropriately and optimally utilize PKM2 as a biomarker for AKI requires its complete characterization. This review highlights the major studies that have addressed the diagnostic and prognostic predictive power of biomarkers for AKI and assesses the potential usage of PKM2 as an early biomarker for AKI. We summarize the current state of knowledge regarding the role of biomarkers and the molecular and cellular mechanisms of AKI. This review will elucidate the biological basis of specific biomarkers that will contribute to improving the early detection and diagnosis of AKI.

Gain Selection Method for Robustness Enhancement in Sliding Mode Control Combined with Decoupled Disturbance Compensator with Unknown Inertia in Industrial Servo Systems

Ji-Seok Han,Tae-Il Kim,Ji-Ho Park,Tae-Ho Oh,Ji-Hyung Lee,Sang-Oh Kim,Sang-Sub Lee,Sang-Hoon Lee,Dong-Il “Dan” Cho 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10

This paper presents a method to enhance robustness in sliding mode control (SMC) combined with decoupled disturbance compensator (DDC). More specifically, a gain selection method for the DDC in industrial servo systems with unknown inertia is developed. The SMC with DDC method is a well-known robust control method which is effective for slowly-varying and bounded disturbances. However, when the gain of the DDC is improperly selected, a large error of the inertia parameter can lead to poor performance such as a large overshoot in the motor position. This paper shows that the disturbance caused by an uncertain inertia can produce a pair of complex conjugate eigenvalues of the error dynamics in the z-domain, which results in the overshoot in both position and velocity. In addition, utilizing this analysis, a gain selection method of DDC is proposed when the ratio of the actual inertia to the nominal inertia is assumed to be bounded. The analytical results are further supported using experiments performed on industrial servo systems with a ball-screw load and a belt load.

실 작업 부하를 이용한 옥수수 수확기용 기어박스의 강도평가와 치면 접촉패턴 해석

김지태 ( Ji-tae Kim ),이호섭 ( Ho-seop Lee ),유호길 ( Ho-gil Yoo ),조승제 ( Seung-je Cho ),우제근 ( Jeakeun Woo ),하창섭 ( Change-sub Ha ),박영준 ( Young-jun Park ) 한국농업기계학회 2021 한국농업기계학회 학술발표논문집 Vol.26 No.2

트랙터 부착형 옥수수 수확기는 트랙터 3-point hitch에 부착되며, PTO로부터 동력을 전달받아 옥수수를 수확하는 농업용 수확기이다. 옥수수 수확기는 서로 다른 옥수수 줄기의 특성과 토양의 특성으로 인하여 일정하지 않은 부하가 수확기에 작용한다. 따라서, 옥수수 수확기용 기어박스의 평가는 실 작업 부하를 기반으로 수행되어야 한다. 본 연구에서는 시뮬레이션을 통한 옥수수 수확기용 기어박스의 평가를 위하여 국내에서 생산 중인 옥수수 수확기용 기어박스의 모델링을 수행하였으며, 옥수수 수확 시 발생하는 실 작업 부하를 계측하였다. 기어박스 모델과 실 작업 부하를 기반으로 기어박스의 강도평가 및 치면 접촉패턴 해석을 수행한 결과, 치면 접촉패턴이 균일하지 않음을 확인하였으며, 이를 해결하기 위해 베어링의 위치와 간격 변화 및 기어의 micro-geometry modification 등의 설계 수정을 수행하였다. 그 결과, 치면 접촉패턴의 특성을 나타내는 치면하중분포계수(K_Hβ)가 크게 낮아졌으며, 기어의 접촉과 굽힘에 대한 안전계수도 크게 향상된 것을 확인하였다.