Ex situ catalytic upgrading of lignocellulosic biomass components over vanadium contained H-MCM-41 catalysts

Kim, B.S.,Jeong, C.S.,Kim, J.M.,Park, S.B.,Park, S.H.,Jeon, J.K.,Jung, S.C.,Kim, S.C.,Park, Y.K. Elsevier Science Publishers 2016 CATALYSIS TODAY - Vol.265 No.-

<P>H-V-MCM-41 catalysts containing 5, 10, and 30 wt% of vanadium were synthesized and applied to the ex situ catalytic pyrolysis (CP) of three polymeric components of lignocellulosic biomass for the first time. Characterization of the catalysts was performed using N-2 adsorption-desorption, XRD, FT-IR, and NH3-TPD. The results of XRD analysis showed that 5 wt% and 10 wt% H-V-MCM-41 catalysts maintained the mesoporous structure, whereas the mesoporous structure was destroyed in 30 wt% H-V-MCM-41 with considerable amount of small V2O5 crystalline outside the framework. NH3-TPD showed that H-V-MCM-41 has mostly weak acid sites and that 10 wt% H-V-MCM-41 had the largest quantity of acid sites due to framework vanadium. In the case of CP of cellulose using Py-GC/MS, 10 wt% H-V-MCM-41 showed the highest catalytic activity for the production of valuable furanic compounds such as furfural because of the enhanced deoxygenation over the acid sites formed on framework vanadium. In the case of CP of xylan as well, 10 wt% H-V-MCM-41 led to the largest yield of mono-aromatics. The production of acetic acid was also promoted by H-V-MCM-41 catalysts. The CP of lignin over H-V-MCM-41 catalysts promoted substantially the production of important feedstock chemicals for the petrochemical industry: phenolics and mono-aromatics. (C) 2015 Elsevier B.V. All rights reserved.</P>

Display of membrane proteins on the heterologous caveolae carved by caveolin-1 in the Escherichia coli cytoplasm

Shin, J.,Jung, Y.H.,Cho, D.H.,Park, M.,Lee, K.E.,Yang, Y.,Jeong, C.,Sung, B.H.,Sohn, J.H.,Park, J.B.,Kweon, D.H. IPC Science and Technology Press ; Elsevier Scienc 2015 Enzyme and microbial technology Vol.79 No.-

Caveolae are membrane-budding structures that exist in many vertebrate cells. One of the important functions of caveolae is to form membrane curvature and endocytic vesicles. Recently, it was shown that caveolae-like structures were formed in Escherichia coli through the expression of caveolin-1. This interesting structure seems to be versatile for a variety of biotechnological applications. Targeting of heterologous proteins in the caveolae-like structure should be the first question to be addressed for this purpose. Here we show that membrane proteins co-expressed with caveolin-1 are embedded into the heterologous caveolae (h-caveolae), the cavaolae-like structures formed inside the cell. Two transmembrane SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins, Syntaxin 1a and vesicle-associated membrane protein 2 (VAMP2), were displayed on the h-caveolae surface. The size of the h-caveolae harboring the transmembrane proteins was ~100nm in diameter. The proteins were functional and faced outward on the h-caveolae. Multi-spanning transmembrane proteins FtsH and FeoB could be included in the h-caveolae, too. Furthermore, the recombinant E. coli cells were shown to endocytose substrate supplemented in the medium. These results provide a basis for exploiting the h-caveolae formed inside E. coli cells for future biotechnological applications.

초기성인의 생활습관과 당뇨에 대한 지식

소선이,마지은,고지윤,김은혜,박현화,서유진,서형은,유은미,이하늬,이혜인,정지연,현혜리,이자형,정덕유,강지숙 이화여자대학교 간호과학대학 2009 이화간호학회지 Vol.- No.43

Purposes :The purposes of this study was to investigate the self-managing status according to the life styles and the diabetic knowledge of early adulthood. The subjects in this study were 240people, the early adult aged twenties to thirties living in the metropolitan area. Data were collected by using self-administered questionnaires that measure about the knowledge of diabetes; the dietetic behavior; the knowledge of diet; the exercise behavior; the knowledge of exercise. Descriptive statistics, t-test, ANOVA, and correlation were used for data analysis. Result :1. At the knowledge of diabetes degree based on the general character, the subjects who had experiences of diabetic education have higher degree of the diabetic knowledge. 2. At the knowledge of diabetes degree according to the life style, the subjects who have regular diet are appeared highly. Also the subjects who don't take much food of animal origin have higher degree. 3. At the knowledge of diet based on the life style, the subjects who don't keep three times meals a day are appeared highly. Also the subjects who have regular diet have higher degree. 4. At the knowledge of exercise according to the life style, the subjects who take extra nutritions 3-4 times a week are appeared highly. Although the subjects tend to know about dietary, exercise and health management, it showed that they actually don't perform what they know in their everyday of life. The reason for this could be the lack of perceived seriousness about diabetes mellitus. Thus as nursing professionals, we should provide them proper health education and support. Moreover, advanced research on the empowerment is warranted.

Effects of Y₂O₃ additions on the oxygen diffusion in top-seeded melt growth processed YBa₂Cu₃O_7-y superconductors

Jun, B.H.,Jung, S.A.,Park, S.D.,Park, B.J.,Han, Y.H.,Kim, C.J. North-Holland 2011 Physica. C, Superconductivity Vol.471 No.21

To understand the effect of Y<SUB>2</SUB>BaCuO<SUB>5</SUB> (Y211)/YBa<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>7-y</SUB> (Y123) interfaces on the oxygen diffusion in single grain YBa<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>7-y</SUB> superconductors, single grain Y123 superconductors with 0.05 and 0.3moles of Y<SUB>2</SUB>O<SUB>3</SUB> additions were fabricated by a top-seeded melt growth (TSMG) process. Y123 compacts with Y<SUB>2</SUB>O<SUB>3</SUB> additions were subjected to melt growth heating cycles with a cooling rate of 1<SUP>o</SUP>C/h through a peritectic temperature (1015<SUP>o</SUP>C) and then annealed at 450<SUP>o</SUP>C for 200h in flowing oxygen. The superconducting temperature (T<SUB>c</SUB>) and critical current density (J<SUB>c</SUB>) were estimated for the three different regions (top surface (s), intermediate (i) and center (c)) of samples. The amount of Y211/Y123 interface area in single grain Y123 superconductors was successfully controlled by Y<SUB>2</SUB>O<SUB>3</SUB> additions. The T<SUB>c</SUB> values of s regions were higher than those of i and c regions, which indicates the presence of more oxygen at the sample surfaces. In addition, the T<SUB>c</SUB> values of i and c regions of the Y123 sample with 0.3mole Y<SUB>2</SUB>O<SUB>3</SUB> addition were higher than those of the same regions of the Y123 sample with 0.05mole Y<SUB>2</SUB>O<SUB>3</SUB> addition due to the promoted oxygen diffusion through Y211/Y123 interfaces and other related defects. In spite of the promoted oxygen diffusion by Y<SUB>2</SUB>O<SUB>3</SUB> addition, the large T<SUB>c</SUB> difference among the regions still existed, which suggests sluggish oxygen diffusion into single Y123 grains.

Key Features in the Operation of KSTAR

Jong-Gu Kwak,Oh, Y. K.,Kim, K. P.,Kim, S. W.,Hong, S. H.,Chu, Y.,Lee, H. J.,Kim, Y. O.,Kim, J.,Park, S. L.,Hahn, S. H.,Park, M. K.,Kim, H. K.,Bak, J. G.,Bae, Y. S.,Ko, W. H.,Lee, S. G.,Lee, J. H.,Jung IEEE 2012 IEEE transactions on plasma science Vol.40 No.3

<P>The Korea Superconducting Tokamak Advanced Research (KSTAR) device is aimed at advanced tokamak (AT) research. Three years have passed since it achieved its first plasma in 2008. Because it is a superconducting machine and is working toward AT research, it has unique features in terms of the machine engineering and operation. The toroidal field (TF) magnet coils are made of Nb<SUB>3</SUB>Sn, which provide high TFs up to 3.5 T, and have been fully tested. The poloidal field (PF) magnet coils, consisting of both Nb<SUB>3</SUB>Sn and NbTi, which have a maximum current of 25 kA in their design, were tested up to 15 kA. A thermal hydraulic analysis is being conducted for PF magnet coil operation. All plasma-facing components (PFCs) are equipped with water cooled graphite tiles and have the capability of being baked up to 350°C. A startup scenario, which considered both the effect of the ferromagnetic material in the cable in conduit conductor jacket of the magnet coils as well as a nonferromagnetic up-down asymmetry in the cryostat structure, was developed and demonstrated its effectiveness by the last two year's reliable operations. Passive stabilizers and in-vessel control coils (IVCCs) are key components to realize AT operation in KSTAR. The segmented IVCC coils were connected to form circular coils for internal vertical control in 2010, and diverted plasmas with high elongation (κ~1.8, δ>;0.6) were achieved. A neutral beam injection (NBI) system was developed aiming at 2 MW, 300 s per ion source which meets the long-pulse requirement of KSTAR. An NBI ion source with a power of 1.7 MW at 100 kV has been commissioned for 10 s. Finally, ELMy H-modes were successfully produced with 1.3-MW NBI power at a plasma current of 0.6 MA in the 2010 campaign. The first H-mode discharge (#4200) in KSTAR was achieved one year earlier than officially planned and was done at B<SUB>T</SUB> = 2 T with I<SUB>p</SUB> = 0.6 MA in a well-balanced double null configuration after boronization on the PFC. Successful operations in the early days of KSTAR including H-mode experiments revealed the capability of advanced and steady-state operation which is essential for the international thermonuclear experimental reactor (ITER) and future fusion reactors.</P>

Eclalbasaponin II Ameliorates the Cognitive Impairment Induced by Cholinergic Blockade in Mice

Jung, W. Y.,Kim, H.,Jeon, S. J.,Park, H. J.,Choi, H. J.,Kim, N. J.,Kim, D. H.,Jang, D. S.,Ryu, J. H. Springer Science + Business Media 2018 Neurochem Res Vol.43 No.2

<P>Eclalbasaponin II derived from Eclipta prostrata L. (Asteraceae) has been reported to have anti-fibrotic, anti-bacterial and autophagic activities, but its effect on cognitive function has not been investigated. We studied the effect of eclalbasaponin II on cholinergic blockade-induced memory impairment in mice using the passive avoidance, Y-maze, and Morris water maze tasks. Eclalbasaponin II (10 or 20 mg/kg, p.o.) significantly ameliorated the cognitive dysfunction induced by scopolamine in the passive avoidance, Y-maze, and the Morris water maze tasks. To identify the mechanism of the memory-ameliorating effect of eclalbasaponin II, acetylcholinesterase (AChE) activity assay, Western blot analysis and electrophysiology were conducted. Eclalbasaponin II inhibited the AChE activity in ex vivo study, and the administration of eclalbasaponin II and its metabolite, echinocystic acid, increased the phosphorylation levels of memory-related signaling molecules, including protein kinase B (Akt) and glycogen synthase kinase-3 beta (GSK-3 beta), in the hippocampus. Although eclalbasaponin II did not affect hippocampal long term potentiation (LTP), echinocystic acid significantly enhanced hippocampal LTP formation (30 mu M). These results suggest that eclalbasaponin II ameliorates cholinergic blockade-induced cognitive impairment via AChE inhibition, LTP formation and the activation of Akt-GSK-3 beta signaling, and that eclalbasaponin II may be a useful to treat cognitive impairment derived from cholinergic dysfunction.</P>

Pt deposited Pt-Pd/C electrocatalysts with the enhanced oxygen reduction activity

Park, J.H.,Sohn, Y.,Jung, D.H.,Kim, P.,Joo, J.B. Korean Society of Industrial and Engineering Chemi 2016 Journal of industrial and engineering chemistry Vol.36 No.-

<P>Reducing the cost of state-of-the-art Pt electrocatalysts while maintaining their oxygen reduction performance is always a hotspot in fuel cell research owing to their significant economic benefit for the commercialization of polymer electrolyte membrane fuel cells. Herein, we report a simple and cost-effective synthesis of Pt-Pd catalysts and a systematic study of their characteristics and catalytic performances for the oxygen reduction reaction (ORR). Pt-Pd bimetallic catalysts were prepared by a simple chemical deposition of Pt on the surface of Pd particles using a commercial Pd/C catalyst. During the synthesis, Pt precursor was reduced, and Pt layers were preferentially overgrown on the surface of the preexisting Pd particles resulting in Pd@Pt core-shell particles, which are favorable for ORR. By varying Pt precursors and the amount of Pt deposited, the physicochemical and electrochemical properties of the Pt-Pd catalysts were optimized. The formation of a thin Pt layer on Pd surface is more favorable, when using Pt(NH3)(4)Cl-2 center dot xH(2)O rather than H2PtCl6 center dot xH(2)O. As the amount of Pt increased from 0 to 10%, the surface properties of metal particles changed to similar to that of Pt, and the resulting catalysts mainly consist of a Pt-rich layer with a Pd core such as the Pd@Pt core-shell configuration. Pt(10%)Pd/C catalyst prepared by using Pt(NH3)(4)Cl-2 center dot xH(2)O exhibited a significant improvement in the ORR with the mass activities of 221 and 53 mA/mgpGm at 0.85 and 0.9 V, respectively, which are beatable values compared to those (219 and 59 mA/mg(Pt) at 0.85 and 0.9 V) of commercial Pt/C catalysts. The performance improvement of our bimetallic Pt-Pd/C catalysts mainly originate from the formation of an active Pt surface on the Pd core. In addition, considering that Pd is generally less expensive than Pt, these catalysts should have much better ORR performance and more feasibility of decreasing the total cost of fuel cells. In this study, the characteristics, electrochemical behaviors, and ORR performance improvements of the simply prepared Pt(x)-Pd/C core-shell catalysts were systemically investigated and are discussed. (C) 2016 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.</P>

Amelioration of neurodegenerative diseases by cell death-induced cytoplasmic delivery of humanin

Park, T.Y.,Kim, S.H.,Shin, Y.C.,Lee, N.H.,Lee, R.K.C.,Shim, J.H.,Glimcher, L.H.,Mook-Jung, I.,Cheong, E.,Kim, W.K.,Honda, F.,Morio, T.,Lim, J.S.,Lee, S.K. Elsevier Science Publishers 2013 Journal of controlled release Vol.166 No.3

Inhibition of the early intracellular event that triggers neurodegenerative cascades and reversal of neuronal cell death are essential for effective treatment of Alzheimer's disease (AD). In this study, a novel therapeutic for AD, a transducible humanin with an extended caspase-3 cleavage sequence (tHN-C3), was developed and showed multiple mechanisms of therapeutic action. These included targeted delivery of anti-apoptotic protein humanin through the blood-brain barrier (BBB) to neuronal cells, specific inhibition of caspase-3 activation to inhibit the early triggering of AD progression, and delivery of humanin into the cytoplasm of neuronal cells undergoing apoptosis where it exerts its anti-apoptotic functions effectively. The tHN-C3 prevented neuronal cell death induced by H<SUB>2</SUB>O<SUB>2</SUB>, or soluble Aβ<SUB>42</SUB>, via Bax binding. In animal models of AD induced by amyloid beta, in Tg2576 mice, and in the rat middle cerebral artery occlusion model of stroke, tHN-C3 effectively prevented neuronal cell death, inflammatory cell infiltration into the brain, and improved cognitive memory. The therapeutic effectiveness of tHN-C3 was comparable to that of Aricept, a clinically approved drug for AD treatment. Therefore, tHN-C3 may be a new remedy with multiple therapeutic functions targeting the early and late stages of neurodegeneration in AD and other brain injuries.

3차원 미니밴 형상 주위의 비압축성 점성 유동 해석

박원규,정영래,박영준,김종섭,홍성훈 釜山大學校生産技術硏究所 1998 生産技術硏究所論文集 Vol.55 No.-

The flow field around a three dimensional minivan-like body has been simulated. This study solves 3-D unsteady incompressible Navier-Stokes equations on a non-orthogonal curvilinear coordinate system using second-order accurate schemes for the time derivatives, and third/second-order scheme for the spatial derivatives. The Marker-and-Cell concept is applied to efficiently solve continuity equation. A H-H type of multi-block grid system is generated around a three dimensional minivan-like body. Turbulent flows have been modeled by the Baldwin-Lomax turbulent model. To validate present procedure, the flows around the ahmed body with 12.5°of slant angle are simulated. A good agreement with other numerical results is achived. After code validation, the flows around a mimivan-like body are simulated. The simulation shows three dimensional vortex-pair just behind body. The flow separation is also observed on the rear of the body. It has concluded that the results of present study properly agreed with physical flow phenomena.

저응력 다결정 규소 미세 구조체의 제작

박경호,이춘수,정영이,이용일,최부연,이종현,유형준 경북대학교 센서기술연구소 1995 센서技術學術大會論文集 Vol.6 No.1

Annealing effects on residual stress of polysilicon microstructures were investigated using cantilever test patterns. 0.5-2μm thick polysilicon films on 2-4μm thick oxide layers were annealed at 900, 1000, and 1100℃ in nitrogen atmosphere for 1 hour. The vertical deflections of cantilever beams were measured by a 3-dimensional optical microscope with 0.01μm resolution and SEM(scnning electron microscope). The estimated maximum residual stresses of as-prepared and 900℃-annealed beams were 7.88x10^(9) and 5.6x10^(8) N/m^(2), respectively. Annealing at 1100℃ for 1 hour was found to be effective to release the residual stress of the polysilicon microstructures.