• Carbon letters
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• 제24권
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• pp.73-81
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• 2017

Interconnected meso/microporous activated carbons were prepared from pumpkin seeds using a simple chemical activation method. The porous carbon materials were prepared at different temperatures (PS-600, PS-700, PS-800, and PS-900) and demonstrated huge surface areas ($645-2029m^2g^{-1}$) with excellent pore volumes ($0.27-1.30cm^3g^{-1}$). The well-condensed graphitic structure of the prepared activated carbon materials was confirmed by Raman and X-ray diffraction analyses. The presence of heteroatoms (O and N) in the carbon materials was confirmed by X-ray photoemission spectroscopy. High resolution transmission electron microscopic images and selected area diffraction patters further revealed the porous structure and amorphous nature of the prepared electrode materials. The resultant porous carbons (PS-600, PS-700, PS-800, and PS-900) were utilized as electrode material for supercapacitors. To our delight, the PS-900 demonstrated a maximum specific capacitance (Cs) of $303F\;g^{-1}$ in 1.0 M $H_2SO_4 $ at a scan rate of 5 mV. The electrochemical impedance spectra confirmed the poor electrical resistance of the electrode materials. Moreover, the stability of the PS-900 was found to be excellent (no significant change in the Cs even after 6000 cycles).

• BMB Reports
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• 제49권6호
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• pp.303-304
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• 2016

Myoblast fusion is important for skeletal muscle formation. Even though the knowledge of myoblast fusion mechanism has accumulated over the years, the initial signal of fusion is yet to be elucidated. Our study reveals the novel function of a phosphatidylserine (PS) receptor, stabilin-2 (Stab2), in the modulation of myoblast fusion, through the recognition of PS exposed on myoblasts. During differentiation of myoblasts, Stab2 expression is higher than other PS receptors and is controlled by calcineurin/NFAT signaling on myoblasts. The forced expression of Stab2 results in an increase in myoblast fusion; genetic ablation of Stab2 in mice causes a reduction in muscle size, as a result of impaired myoblast fusion. After muscle injury, muscle regeneration is impaired in Stab2-deficient mice, resulting in small myofibers with fewer nuclei, which is due to reduction of fusion rather than defection of myoblast differentiation. The fusion-promoting role of Stab2 is dependent on its PS-binding motif, and the blocking of PS-Stab2 binding impairs cell-cell fusion on myoblasts. Given our previous finding that Stab2 recognizes PS exposed on apoptotic cells for sensing as an "eat-me" signal, we propose that PS-Stab2 binding is required for sensing of a "fuse-me" signal as the initial signal of myoblast fusion.

• Archives of Pharmacal Research
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• 제19권2호
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• pp.116-121
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• 1996

Antisense oligonucleotides seem to provide a promising new tool for the therapy. Choi et al. (1995) reported antisense phosphorothioate oligonucleotides (PS-ODN, 25 mer) complementary to TGF-.betha. mRNA designed for scar formation inhibitor to eliminate scars, which was caused by undesired collagen deposition due to overexpression of TGF-.betha., in wounded skin. PS-ODN were evaluated in vitro for skin penetration using normal and tape-stripped damaged rat skin. The in vitro skin transports were carried out with partially modified PS-ODN (6S) and fully modified PS-ODN (25S). The cumulative amount of PS-ODN (6S) penetrated through normal rat skin was $0.234{\pm}0.041{\mu}g/cm^2$ and that of tape-stripped damaged rat skin was $1.077{\pm}0.301{\mu}g/cm^2$ over 8 hrs. PS-ODN (25S) can not be found in receptor medium through normal skin due to high molecular weight (Mol.Wt.=8,000) and polyanionic charge. However, the cumulative amount of PS-ODN (25S) penetrated across damaged rat skin in PBS was $0.340{\pm}0.296{\mu}g/cm^2$ over 8 hrs. The absense of dermis raised the cumulative amount of PS-ODN (6S) penetrated through rat skin. And the fluxes of PS-ODN (6S) and PSODN (25S) at 8hrs across damaged rat skin were $134.63{\pm}37.67{\mu}g/cm^2$ h, and $42.50{\pm}36.95ng/cm^2$ h, respectively. While PS-ODN (25S) was stable in 10% heat inactivated fetal bovine serum (FBS) during 24 hrs, PS-ODN (6S) was less stable than PS-ODN (25S), but was markedly stable than unmodified phosphodiester. It is suggested that the cumulative amount of PS-ODN (6S) penetrated through damaged rat skin is larger than that of PS-ODN (25S) since the former is easier to degrade by nuclease than the latter and then is apt to penetrate into skin. Thus, PS-ODN represents a logical candidate for further evaluation due to the potential for delivery into the wounded skin.

• Applied Biological Chemistry
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• 제37권5호
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• pp.343-348
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• 1994

A. tumafaciens C58로부터 $^3H-thymidine$으로 표지한 Ti plasmid를 분리하여 lyophilization-rehydration법으로 octadecyl rhodamine B로 표지한 liposome에 내포시켰다. Liposome조제에 사용한 지질은 phosphatidylserine(PS)을 사용한 PS liposome과, PS와 cholesterol(Chol)을 같은 mole비로 섞은 PS-Chol이었다. 꽃담배 원형질체는 0.1% macerozyme과 1.5% cellulase를 처리하여 유리시키고 불연속성 농도구배 원심분리로 정제하였다. $^3H-Ti plasmid$를 포함하고 있는 liposome$(1\;{\mu}mole\;PS)$을 5 mM $Ca^{2+}$과 10% PEG로 처리하여 꽃담배 원형질체$(10^6)$과 융합시켰다. 원형질체와 융합한 liposome의 양은 rhodamine B의 형광으로 측정하고 원형질체에 도입된 Ti plasmid의 양은 tritium의 방사능으로 측정하였다. 이때 PS liposome에서는 7.9%가 PS-Chol liposome에서는 7.2%의 liposome이 원형질체와 융합하였는데 융합과정에서 PS liposome서는 약 60%의 내용물이 유실되었고 PS-Chol liposome에서는 약 30%의 내용물이 유실되었다. 따라서 Ti plasmid를 식물원형질체에 도입하는데는 PS 보다는 PS-Chol로 구성된 liposome이 효율적인 것으로 나타났다. PS-Chol liposome을 사용할 경우에 1개의 원형질체에 약 1,700개의 Ti plasmid가 결합하고 있음으로 lyophilization-rehydration법을 사용하여 Ti plasmid를 식물원형질체에 도입할 경우에 식물의 형질전환 효율을 높일 수 있을 것임을 시사하여 준다.

• 한국환경농학회지
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• 제17권2호
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• pp.107-116
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• 1998

광분해 촉진에 의한 작물 및 토양중 잔류농약의 인위적인 경감을 위하여 자연계에 천연적으로 존재하거나 또는 합성화합물중에서 감광작용을 갖을 것으로 예상되는 40여종에 대하여 감광작용을 검정하여 6종의 화합물을 선정하고 고추와 토마토에 사용되는 살균제중 procymidone,vinclozolin 및 carbendazim을 관행법에 따라 상기 작물에 살포한 후 감광제를 처리하여 다음과 같은 결과를 얻었다.1.Acetone에 용해되어 있는 procymidone,vinclozolin, carbendazim의 최대흡장 파장 (${\lambda}$max)은 모두 209nm 이었고,최대 molar absorptivity (${\varepsilon}$max)는 각각 853,853,8740이었다.2.40여종의 자연계에 천연적으로 존재하는 화합물과 합성 유기 및 무기화합물의 감광작용을 탐색하여 방향족 ketone계인 PS-1,방향족 amine계인 PS_2, quinone계인 PS-3,무기화합물인 PS-4,유기염산인 PS-5,광촉매제인 PS-6를 선발하였다.3.감광제 살포에 의한 토양중 농약의 광분해 촉진효과에서 procymidone의 경우에는 감광제 PS-2를 처리 한 후 3일에 대조구 잔류량의 59%로 감소하여 그 효과가 현저하였다.4.토양에서 vinclozolin의 경우에는 감광제 PS-2를 처리 한 후 1일 잔류랑이 된 양이 대구조의 71%로 그리고 15일 후에는 21%로 감소하였다.

• 한국화재소방학회논문지
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• 제33권1호
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• pp.69-75
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• 2019

본 연구에서는 5종의 섬유강화플라스틱(Fiber Reinforced Plastic, FRP), 폴리스티렌(Polystylene, PS), 폴리카보네이트(Polycarbonate, PC), 폴리프로필렌(Polypropylene, PP), 폴리염화비닐(Polyvinyl chloride, PVC) 판을 콘칼로리미터(Cone calorimeter, ISO 5660)를 이용하여 연소성을 시험하였다. 그 결과 PVC판은 최대열방출률($HRR_{peak}$)이 $44.65kW/m^2$, 최대평균열방사율(MARHE)이 $30.97kW/m^2$로 가장 낮게 나타났고, PS판은 $HRR_{peak}$은 $773.44kW/m^2$, MARHE는 $399.14kW/m^2$으로 가장 높게 나타났다. 일산화탄소의 평균($CO_{mean}$) 발생량은 PC판과 PS판이 최대 3.88배로 가장 많이 발생하였고, 반대로 이산화탄소($CO_{2mean}$)의 평균 발생량은 PS판과 PP판이 최대 4.88배로 가장 많이 발생하였다. 또 PS판은 다른 플라스틱보다 연기성능지수(SPI)가 74.81%~95.99% 감소하였고, 연기성장지수(SGI)는 76%~300%, 연기강도(SI)는 917.73%~9607.57% 증가하여 연기위험성이 높다는 것을 알 수 있었다. 따라서 PS판은 열적 측면에서나 연기 측면 모두 연기로 인한 인명피해의 위험성이 가장 높았음을 알았다.

• 생명과학회지
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• 제19권6호
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• pp.744-750
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• 2009

토양에서 분리한 세포외 다당류 생산균주 PS-12는 형태학적, 생리학적, 화학적 분석에 의하여 Bacillus sp.에 속하는 균주로 동정되었으며, 분리균주 PS-12는 Bacillus sp. PS-12로 명명하였다. Bacillus sp. PS-127가 생산하는 세포외 다당류는 에탄올 침전, cetylpyridinium chloride (CPC) 침전과 gel permeation chromatography를 이용하여 정제하였으며, 정제된 다당류 PS-12의 당조성은 glucose, mannose, galactose와 fucose가 7:3.2:2:1의 몰비로 구성되어있었다. Bacillus sp. PS-12로부터 분리된 다당류 PS-12를 이용하여 면역증강효과를 확인하였다. TNF-${\alpha}$ 및 lL-6 측정은 RAW264.7 대식세포주를 사용하였으며 cytokine 정량을 위하여 ELISA kit를 이용하였다. RAW264.7 세포주에 대한 PS-12의 세포독성을 확인하기 위하여 세포독성이 10% 미만을 나타내는 농도인 2 ${\mu}g$/ml을 PS-12의 최대농도로 측정하였다. PS-12는 ${\mu}g$/ml에서 TNF-${\alpha}$를 정상세포보다 50배 이상 높은 수치로 생산하였다. 또한 lL-6의 생산을 농도 의존적으로 증가시켰다. 이러한 결과로부터 PS-127가 면역세포에 대해 세포독성을 거의 나타내지 않는 농도에서 대식세포로부터 TNF-${\alpha}$와 11-6의 cytokine 생산을 함으로써 면역증강효과를 나타낸다는 것을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제19권11호
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• pp.1482-1489
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• 2009

In this study, we investigated the anti-proliferative effect of polysaccharides from Salicornia herbacea on HT-29 human colon cancer cells. Crude polysaccharides from S. herbacea (CS) were prepared by extraction with hot steam water, and fine polysaccharides from S. herbacea (PS) were obtained through further size exclusion chromatography. The anti-proliferative effect of CS and PS were measured using the MTS assay, apoptosis analysis, cell cycle analysis, and RT-PCR. HT-29 cells were treated with CS or PS at different dosages (0.5, 1, 2, 4 mg $ml^{-1}$) for 24 or 48 h. CS and PS inhibited proliferation and stimulated apoptosis of cells in a dose-dependent manner. Flow cytometric analysis after Annexin V-FITC and PI staining revealed that treatment with CS or PS increased total apoptotic death of cells to 24.99% or 91.59%, respectively, in comparison with the control (13.51 %). PS increased early apoptotic death substantially - up to 12 times more than the control. Treatment with CS or PS resulted in a concentration-dependent increase of the G2/M cell population of the cell cycle as determined by flow cytometry. G2/M arrest was induced significantly with the highest concentration (4 mg $ml^{-1}$) of PS. RT-PCR was performed to study the correlation between G2/M arrest and transcription of cell cycle control genes. The anti-proliferative activity of CS and PS was accompanied by inhibition of cyclin B1, and Cdc 2 mRNA. Moreover, both CS and PS induced expression of the p53 tumor suppressor gene and the Cdk inhibitor p21. These results suggest that polysaccharides from S. herbacea have anti-cancer activity in human colon cancer cells.

• Bulletin of the Korean Chemical Society
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• 제26권8호
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• pp.1260-1264
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• 2005

Three new quaternary tantalum thiophosphates, $K_{0.18}TaPS_6,\;K_{0.28}TaPS_6,\;and\;Rb_{0.09}TaPS_6$ have been synthesized by using reactive alkali metal halide fluxes and structurally characterized by single crystal X-ray diffraction techniques. The crystal structures of $K_{0.18}TaPS_6,\;K_{0.28}TaPS_6,\;and\;Rb_{0.09}TaPS_6$ contain 3-dimensional open framework anions, $[TaPS_6]^{x-}$(x = 0.09, 0.18, 0.28) with the empty channel which disordered alkali metal cations, $K^+\;and\;Rb^+$ are located in. Crystal data: $K_{0.18}TaPS_6$, tetragonal, space group$I4_1$/acd (no. 142), a=15.874(3) $\AA$, c=13.146(4) $\AA$, V=3312.7(12) ${\AA}^3$, K, Z=16, R1=0.0545. Crystal data: $K_{0.28}TaPS_6$, tetragonal, space group $I4_1$/acd (no. 142), a=15.880(2) $\AA$, c=13.134(3) $\AA$, V=3312.1(10) ${\AA}^3$, Z=16, R1=0.0562. Crystal data: $Rb_{0.09}TaPS_6$, tetragonal, space group I41/acd (no. 142), a=15.893(3) $\AA$, c=13.163(4) $\AA$, V=3324.7(15) ${\AA}^3$, Z=16, R1=0.0432.

• Structural Monitoring and Maintenance
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• 제5권2호
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• pp.189-204
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• 2018

This paper examines the seismic responses of a reinforced concrete (RC) frame core-tube building with pre-pressed spring self-centering energy dissipation (PS-SCED) braces. The PS-SCED brace system consists of friction devices for energy dissipation, pre-pressed combination disc springs for self-centering and tube members as guiding elements. A constitutive model of self-centering flag-shaped hysteresis for PS-SCED brace is developed to better simulate the seismic responses of the RC frame core-tube building with PS-SCED braces, which is also verified by the tests of two braces under low cyclic reversed loading. Results indicate that the self-centering and energy dissipation capabilities are well predicted by the proposed constitutive model of the PS-SCED brace. The structure with PS-SCED braces presents similar peak story drift ratio, smaller peak acceleration, smaller base shear force and much smaller residual deformations as compared to the RC frame core-tube building with bucking-restrained braces (BRBs).