3D flexible Si based-composite (Si@Si₃N₄)/CNF electrode with enhanced cyclability and high rate capability for lithium-ion batteries

Kim, Si-Jin,Kim, Min-Cheol,Han, Sang-Beom,Lee, Gyu-Ho,Choe, Hui-Seon,Kwak, Da-Hee,Choi, Sun-Yong,Son, Byung-Goo,Shin, Myoung-Sun,Park, Kyung-Won Elsevier 2016 Nano energy Vol.27 No.-

<P><B>Abstract</B></P> <P>Despite extremely high capacity of Si-based anodes in lithium-ion batteries (LIB), Si-based materials have shown a structural collapse caused by a volumetric expansion/contraction during the cycling process. The conventional electrode structure, which consists of active materials, a current collector, a conducting agent, and a binder, actually showed a low loading of active material due to the other heavy components. In this study, we prepared a 3D flexible Si-composite electrode consisting of core (Si)-shell (Si<SUB>3</SUB>N<SUB>4</SUB>) NPs (Si@Si<SUB>3</SUB>N<SUB>4</SUB>) and carbon nanofibers (denoted as Si-composite/CNF). The Si-composite/CNF was directly utilized as an anode in the absence of the other components was electrochemically evaluated using a coin-type cell. The Si-composite/CNF showed a high capacity of 665mAhg<SUP>−1</SUP> at a fairly high current density of 10Ag<SUP>−1</SUP> and an extremely low capacity loss for 2000 cycles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We prepared Si-composite/CNF exhibits a 3D flexible Si-composite electrode. </LI> <LI> The electrode consists of core (Si)-shell (Si<SUB>3</SUB>N<SUB>4</SUB>) NPs (Si@Si<SUB>3</SUB>N<SUB>4</SUB>) and carbon nanofibers. </LI> <LI> The Si-composite/CNF was directly utilized as an anode. </LI> <LI> Si-composite /CNF exhibited high specific capacity and improved high rate cycling performance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

<i>Toxoplasma gondii</i> protects against H₂O₂‐induced apoptosis in ARPE‐19 cells through the transcriptional regulation of apoptotic elements and downregulation of the p38 MAPK pathway

Choi, Si‐,Hwan,Park, Sung Jun,Cha, Guang‐,Ho,Quan, Juan Hua,Chang, Nam‐,Sik,Ahn, Myoung‐,Hee,Shin, Dae‐,Whan,Lee, Young‐,Ha Blackwell Publishing Ltd 2011 Acta ophthalmologica Vol.89 No.4

<P><B>Abstract.</B></P><P><B>Purpose: </B> Toxoplasmosis, which is caused by the protozoan parasite <I>Toxoplasma gondii</I>, can lead to severe visual impairment. <I>T.?gondii</I> inhibits or delays programmed cell death caused by various apoptotic triggers; however, the mechanisms involved in the <I>T</I>.?<I>gondii</I>‐induced suppression of apoptosis in retinal cells have not been analysed in detail.</P><P><B>Methods: </B> We investigated the role of <I>T</I>.<I>?gondii</I> infection in H<SUB>2</SUB>O<SUB>2</SUB>‐induced apoptosis in human retinal pigment epithelial cells (ARPE‐19) by monitoring the activities of apoptosis‐regulating molecules and mitogen‐activated protein kinases (MAPKs), including p38 MAPK. We also examined the gene downstream from p38 MAPK.</P><P><B>Results: </B> <I>T.?gondii</I> infection significantly inhibited the cellular toxicity of H<SUB>2</SUB>O<SUB>2</SUB> (500 μ<SMALL>m</SMALL>) and increased cell viability in a multiplicity of infection (MOI)‐dependent manner by reducing DNA fragmentation and reactive oxygen species (ROS) generation in ARPE‐19 cells. Western blot analysis also showed that <I>T</I>.?<I>gondii</I> infection prevented the host cell expression of pro‐apoptotic factors, such as Bad and Bax, and the activation of caspase‐3. Infection with <I>T</I>.?<I>gondii</I> increased the expression of the anti‐apoptotic factor Bcl‐2 in ARPE‐19 cells under oxidative stress. In accordance with these findings, <I>Toxoplasma</I> infection was protective enough to suppress the phosphorylation of p38 MAPK following H<SUB>2</SUB>O<SUB>2</SUB> treatment. Exposure to H<SUB>2</SUB>O<SUB>2</SUB> increased the expression of heme oxygenase‐1 (HO‐1) in ARPE‐19 cells, and its expression was significantly inhibited in H<SUB>2</SUB>O<SUB>2</SUB>‐treated infected cells.</P><P><B>Conclusion: </B> The protective function of <I>T</I>.?<I>gondii</I> infection against ROS‐induced apoptosis results from changes in the expression of apoptotic molecules and the downregulation of stress‐induced intracellular signalling.</P>

백서 척수후근절로부터 슈반세포의 효과적인 체외 배양법

김성민,이종호,김남열,안강민,최원재,최시호,차미주,이주영,황순정,장정원,명훈,최진영,서병무,정필훈,김명진 大韓顎顔面成形再建外科學會 2003 Maxillofacial Plastic Reconstructive Surgery Vol.25 No.4

Schwann cells(SCs), an important component of the peripheral nervous system, intract with nerous to mutually support growth and replication for the peripheral nerve regentation. Recently, ading SCs to the lumen of guidance channel is widely tried to improve regeneration or to make regeneration possible over otherwise irreparable gaps. however, it is not easy to isolate and multiplicate SCs as much as enough to help the axonal regeneration. For the allogeneic SCs source for tubular nerve guidance, we developed a little bit improved technique of harvesting and multiplicating SCs. by culturing dispersed dorsal root ganglia in specially designed medium with growth factors and serial processing, we repeatedlly generate relatively homogenous SC cultures. Our technique was compared with other methods of literature using immunostaining methods such as GFAP, S100, BDNF and the total SC count assessment at different time interval after primary culture.

광양만에서 춘계와 하계 영양염류 첨가가 식물플랑크톤군집의 성장에 미치는 영향

배시우,김동선,최현우,김영옥,문창호,백승호,Bae, Si Woo,Kim, Dongseon,choi, Hyun-Woo,Kim, Young Ok,Moon, Chang Ho,Baek, Seung Ho 한국해양학회 2014 바다 Vol.19 No.1

춘계와 하계 광양만에서 식물플랑크톤 군집구조와 그들의 성장에 영향을 미치는 영양염제한 특성을 파악하기 위해서 만내외측의 20개 정점에서 생물학적 요인과 무생물학적 요인을 조사했다. 또한 식물플랑크톤 군집에 대한 영양염 첨가 효과를 알아보기 위해서 실험실에서 현장 20개 정점의 표층수를 이용하여 생물검정실험을 수행하였다. 전체 식물플랑크톤 군집의 90%이상을 규조류가 차지하였다. 이들 규조류중 Eucampia zodiacus와 Skeletonema costatum-like 종이 춘계와 하계에 각각 우점하였다. E. zodiacus와 S. costatum-like 규조류의 개체군 밀도가 춘계와 하계에 높은 밀도를 유지하게 된 이유를 간단히 설명하면, E. zodiacus 의 성장은 춘계 투명도가 높게 나타나 유광층내 광량의 증가가 원인으로 생각된다. 즉 유광층내 광량의 증가는 E. zodiacus의 개체수를 폭발적으로 증가시킬 수 있는 방아쇠 역할을 한 것으로 판단된다. 하계에 S. costatum-like이 전해역에서 우점한 이유는, 섬진강 담수 유입에 의한 낮은 염분과 함께 공급된 다량의 영양염은 그들 생물의 증식에 중요한 bottom-up 효과를 보였다고 판단된다. 실험실의 생물검정실험에서는 비록 내만(정점 8)과 외해(정점 20)에서 식물플랑크톤 군집의 최대 성장율은 유사하였지만, 인산염에 대한 반포화계수($K_s$)는 내만정점보다 약간 낮았다. 상대적으로 낮은 영양염농도에 적응한 세포는 낮은 인산염농도에서 충분히 성장할 수 있고, 다른 미세조류에 비하여 낮은 영양염농도의 조건에서 경쟁의 우위를 차지 할 것이다. 특히, 하계의 N영양염 첨가군의 효율은 대조군과 P영양염 첨가군에 비해서 높았다. 이는 광양만에서 하계에 N영양염의 공급이 섬진강을 통하여 계속적으로 유입되지만, 빠른 식물플랑크톤의 증식으로 인하여 N영양염 제한이 일어날 수 있다는 것을 시사할 수 있다. 반면, 규산염은 식물플랑크톤의 성장에 영향을 미치는 제한인자로 나타나지 않았고, 규조류의 분해로 인하여 Si의 재순환과 담수로부터 공급된 높은 규산염농도는 광양만에서 규조류 생태계를 유지할수 있는 유리한 조건이라 생각된다. In order to estimate the effect of nutrients addition for phytoplankton growth and community compositons in spring and summer season, we investigated the abiotic and biotic factors of surface and bottom waters at 20 stations of inner and offshore areas in Gwangyang Bay, Korea. Nutrient additional experiments were also conducted to identify any additional nutrient effects on phytoplankton assemblage using the surface water for the assay. Bacillariophyceae occupied more than 90% of total phytoplankton assembleges. Of these, diatom Eucampia zodiacus and Skeletonema costatum-like species was mainly dominated in spring and summer, respectively. Here, we can offer the season why the two diatom population densities were maintained at high levels in both seasons. First, light transparency of spring season in the euphotic zone was greatly improved in the bay. This improvement is one of important factor as tigger of increase in E. zodiacus population. Second, low salinity and high nutrient sources supplied by Seomjin River discharge are a main cue for strong bottom-up effects on S. costatum-like species during the summer rainy season. Based on the algal bio-assays, although maximum growth rate of phytoplankton communities at inner bay (St.8) were similar to those of outer bay (St.20), half-saturation constant ($K_s$) for phosphate at outer bay was slightly lower than those of inner bay. This implied that adapted cells in low nutrient condition of outer bay may have enough grown even the low phosphate and they also have a competitive advantage against other algal species under low nutrient condition. In particular, efficiency of N (+) addition in summer season was higher compared to control and P added experiments. In the bay, silicon was not a major limiting factor for phytoplankton growth, whereas nitrogen (N) was considered as a limiting factor during spring and summer. Therefore, a sufficient silicate supply form water mixing Si recycled from diatom decomposition and river water is favorable form maintaining diatom ecosystems in Gwangyang Bay.

응급의료센터에서 신경색의 조기진단

최경호,오동렬,이원재,박규남,박승현,황두영,김형국,정시경,김영민,김세경 大韓應急醫學會 1998 대한응급의학회지 Vol.9 No.4

To evaluate appropriate diagnostic studies for renal infartion in emergency medical center, we analysed 33 patients of renal infarction treated in this hospital for last 8 years. Eleven patients, 4 trauma associated and 7 aortic disease associated patients were excluded. They are 11 males and 11 females with a mean age of 51 years. Fourteen came to the emergency medical center and seven came to the outpatient department, in the other one patient renal infarction was developed during hospitalization with other disease. On their past history they had hypertension in 9, valvular heart disease in 5, and diabetic mellitus in 4 patients. Abdominal or flank pain was noted in 17 of 22(77%). The other symptoms were vomiting, nausea, fever and so on. On microscopic examination of initial urine in hospital, 5 patients showed more than 10 red blood cells by high power field examination. The mean lactic dehydrogenase level was 1,239 I.U/L(normal range 218-472 I.U/L), while the mean aspartate aminotransferase and mean alanine aminotransferase were 51 I.U/L(normal range 13-36 I.U/L) and 44 I.U/L(normal range 5-33 I.U/L). Abdominal ultrasonography showed positive findings in 5 of 16(31%), of which 3 were confirmed by Doppler ultrasonography. In 18, computed tomography was done and all those showed positive findings of renal infarction(100%). In conclusion, it is important that identify the elevated lactic dehdrogenase level in case of any suspicion about renal infarction and confirm by computed tomography.

수종 한약재가 백혈병 세포에 미치는 영향에 대한 연구

崔湖榮,金澤,柳志昌,卞德市,盧昇鉉 대한본초학회 1999 大韓本草學會誌 Vol.14 No.1

I am reporting here a syntematic in vitro examination for specificity of anti-cancer effect of several oriental herbs, which have been used frequently for cancer pateints(therapy), on Molt-4 LCL(Lymphoblastoid Cell Line) Leukemic cells in relation to its density and time of incubation. 1. ErOH extract of Jujubae Fructus reduced Molt-4 cell's survival rate effectively after 48 hours' treatment at 1000㎍/㎖'s density and it reduced survival rate of LCL effectively after 12 hours' treatment at 1000㎍/㎖'s density. 2. EtOH extract of Cordyceps reduced LCL's survival rate effectively after 36 hour's treatment at 1000㎍/㎖'s density. 2. EtOH extract of Fici Fructus reduced LCL's survival rate effectively after 36 hours' treatment at 1000㎍/㎖'s density. 4. EtOH extract of Trionycis reduced Molt-4 cell's survival rate even at 500㎍/㎖ density and further effective at 1000㎍/㎖ density after 24 hours treatment and it killed the cells completely at 1000㎍/㎖ density after 48 hours treatment, It also Killed LCL completely after 12 hours and 36 hours' treatment at 1000㎍/㎖'s density. 5. EtOH extract of Biotae Cacumen reduced LCL's survival rate effectively after 12 hours' treatment at 1000㎍/㎖'s density, and after 36 hours treatment it reduced LCL's survival time very effectively. 6. EtOH extract of Psoraleae Fructus reduced Molt-4 cell's survival rate very effectively after 24 hours' treatment at 500㎍/㎖ and 1000㎍/㎖'s density, and after 48 hours' treatment at 250㎍/㎖'s density it reduced effectively and it killed the cell completely at 500㎍/㎖ and 1000㎍/㎖'s density. It also killed LCL completely after 12 hours and 36 hours' treatment at 1000㎍/㎖'s density. I hope to proceed with more advanced experiment in vivo and clinically as for the two kinds of oriental herbs and another herbs effective for leukemia.

Glycol Oleates의 합성과 절삭유제로서의 물성

최형기,이호식,이치우,강신춘,노시태 한양대학교 공학기술연구소 1993 공학기술논문집 Vol.2 No.1

Glycololeates for the application of cutting fluid were synthesized from oleic acid and glycols such as ethylene glycol, diethylene glycol and triethylene glycol. The ratio of glycol-monooleate and dioleate in product according to the reaction condition was analyzed by TLC, CC and HPLC. Properties of glycololeates as cutting fluid were examined by various testing methods such as profile test, pH test, anti-foaming test friction coefficient test and emulsion stability test to compare those of base oil and cutting fluid trading in the market. Non-catalytic reaction of glycololeates synthesis was showed too low conversion rate, but too fast conversion rate and deep color deterioration of products was obtained with acid-catalyses reaction. Using the SnCl2 catalyst, conversion rate was medium range and products which suitable for the application of cutting fluid with mild colored and with desirable mono- and di-oleate composition was obtained. Cutting fluidal properties of glycololeates with SnCl2 catalyst were better than those of base oil, and were similar level to those of cutting fluid containing various additives.

흰쥐에서 심정지후 Pentoxifylline이 뇌의 허혈-재관류 손상에 미치는 효과

정시경,김영민,오동렬,최경호,박승현,이운정,박규남,유은영,이원재,김세경 大韓應急醫學會 1999 대한응급의학회지 Vol.10 No.2

Background: Two major events occurring in the cerebral hemodynamics after successful resuscitation from cardiac arrest are reactive hyperemia and postischemic hypoperfusion. In this study, we examined the effect of Pentoxifylline(PTX) on the rat brain following cardiac arrest. Methods: Fourteen rats were anesthetized and artificially ventilated. Cardiac arrest was produced by chest compression and clamping of tracheal tube for 3 minutes in ketamine anesthetized rats. Circulation was restored by standard cardiopulmonary resuscitation methods. In 7 rats, PTX 10mg/kg was infused at 10min after cardiac arrest(PTX group). In the other 7 rats, same amount of normal saline was infused(control group). Results: In both groups, hemodynamic variables, neurologic deficit(ND) score and histopathologic findings of hippocampal CA1 neurons were observed. Hemodynamic variables and ND score were not significantly different between two groups. Delayed ischemic neurons of hippocampal CA1 were decreased in PTX group(2.2±2.4%) compared with control group(9.1±1.2%). Conclusions: We conclude that PTX prevented development of delayed ischemic neurons in hippocampal CA1 after cardiac arrest. PTX may be useful in emergency situations following cardiac arrest.

초저온 냉기를 이용한 한냉치료후 동통유발점압통역치의 변화

홍대종,최기섭,박시복,김영호 大韓再活醫學會 1999 Annals of Rehabilitation Medicine Vol.23 No.1

境界要素法에 의한 3次元 基礎一地盤 相互作用 시스템의 地震解析

權映錄,宋始榮,姜圓鎬,崔光圭,柳又秀 동아대학교 공과대학 부설 한국자원개발연구소 1990 硏究報告 Vol.14 No.1

In this study, the seismic analysis procedure of foundation-soil interaction system is presented. With the assumption of isotropic material properties and infinitesimal strain theory, the boundary element models of three dimensional foundation plate an semi-infinite soil medium are coupled together, using the compatiblity condition of displacements and equilibrium condition of surface tractions on the contact surface. Through the results of the examples in which the seismic responses of the foundation subjected to the SV-wave and the P-Wave, it is shown that the translational motions are decreased and the rocking motion is occured in higher frquency range.