Hybridization of semiconductor materials with carbon nanotubes (CNTs) is a recent field of interest in which new nanodevice fabrication and applications are expected. In this work, nanowire type GaAs structures are synthesized on porous single-wall carbon nanotubes (SWCNTs) as templates using the molecular beam epitaxy (MBE) technique. The field emission properties of the as-synthesized products were investigated to suggest their potential applications as cold electron sources, as well. The SWCNT template was synthesized by the arc-discharge method. SWCNT samples were heat-treated at 400˚C under an N2/O2 atmosphere to remove amorphous carbon. After heat treatment, GaAs was grown on the SWCNT template. The growth conditions of the GaAs in the MBE system were set by changing the growth temperatures from 400˚C to 600˚C. The morphology of the GaAs synthesized on the SWCNTs strongly depends on the substrate temperature. Namely, nano-crystalline beads of GaAs are formed on the CNTs under 500˚C, while nanowire structures begin to form on the beads above 600˚C. The crystal qualities of GaAs and SWCNT were examined by X-ray diffraction and Raman spectra. The field emission properties of the synthesized GaAs nanowires were also investigated and a low turn-on field of 2.0 V/μm was achieved. But, the turn-on field was increased in the second and third measurements. It is thought that arsenic atoms were evaporated during the measurement of the field emission.
PDT is an established cancer treatment modality. This can be attributed to the attractive basic concept of PDT; Combination of two therapeutic agents, a photosensitizing drug and light, which are relatively harmless by themselves but when combined, cause more or less selective tumor destruction. Hematoporphyrin-derived photosensitizers are known to be stable and highly efficient. In this study, we conducted a series of experiments to develop light-induced anticancer drugs against oral cancer cells. We tested the cytotoxicity of photodin by MTT assay and observed cell death pattern (apoptosis or necrosis) by hoechst 33342 and propidium iodide staining methods after PDT. IC50 value of photodin was 0.65 ug/ml. At higher doses of photodin ( > 7.8 ug/ml), cancer cells died exclusively from necrosis after PDT. By contrast, at IC50 value, photodin induced cancer cell to undergo apoptotic cell death. The induction begins approximately 6 hours after PDT. We investigated intracellular localization of photodin by oral cancer cell via confocal laser scanning microscopy. Oral cancer cells dual-stained with photodin and organelle-specific fluorescence probes (Mitotracker, Lysotracker, ER-Tracker) revealed that an intracellular fluorescence distribution was restricted to cytoplasmic compartments with no detectable fluorescence in the nucleus. Confocal images of cells containing photodin were overlapped with the mitochondria-specific fluorescence probe images of the same cells. These results demonstrated that photodin may play the role of a photosensitizer for oral squamous cancer cells without swelling and inflammation. Therefore, photodin-based PDT is a suitable treatment for oral cavity carcinoma patients.
The purpose of this research was to investigate whether the perception of KPIs by restaurant managers from financial and non-financial perspectives was affected by BSC implementation. The perceptions that were examined were importance, adoption, performance, and utilization of KPIs. We surveyed managers from multinational restaurant chains that were adopting BSC and those that were not. From a non-financial perspective, the difference in perceived importance between BSC adopted firms and firms that did not adopt BSC was significant. The managers of BSC adopted firms perceived KPIs more seriously than the others. Secondly, according to the managers' working experiences, the difference of perceived utilization in the internal business process perspective was significant between BSC adopted firms and firms that did not adopt BSC. In addition, from the learning and growth perspective, the difference in perceived adoption and utilization between the two groups was significant. Finally, in the BSC adopted firms, the perceived importance of the managers affected the other perceptions like adoption and utilization from both the financial and non-financial perspectives.
Polysulfone막의 효율을 향상시키기 위하여 막에 브롬화 시킨 후 막의 구조 및 기체투과 특성에 대해 연구하였다. 막의 특성은 FT-IR, 1H-NMR, TGA, Contact angle 등을 사용하여 조사하였고, 브롬화된 막의 기체투과 특성을 알아보기 위해 He, N2, CO2, O2를 사용하였다. 브롬화된 Polysulfane막의 기체투과결과 브롬의 양이 증가할수록 투과도는 감소하고 투과 선택도는 증가하는 결과를 얻을 수 있었다. 그 중 질소는 불소화에 따라서 가장 큰 영향을 받아 투과도가 최고 36%까지 낮아지는 결과를 나타내었으며, 이산화탄소에 대한 질소의 투과선택도는 15% 이상의 매우 향상된 결과를 나타내었다.
DNA sequencer는 template로 이용하는 DNA의 quality와 sequencing 반응 산물의 정제 방법, 그리고 gel 농도에 민감하다고 알려져 있다. 이에 우리는 plasmid DNA의 준비, 정제, sequencing 반응, gel 농도와 injection medium 등에 대한 최적 조건을 구축하기 위한 연구를 수행하였다. Plasmid DNA 준비과정에서 phenol을 사용한 것 보다 chloroform을 사용한 것이 평균 reading length가 532 bp에서 684 bp로 향상 되었으며, 2.5% DMSO를 첨가한 것이 첨가하지 않은 것에 비해 200 bp 더 길게 염기서열 분석이 되었다. 또한, sequencing 반응산물 정제 시 50 mM EDTA와 0.6 M sodium acetate를 미리 섞어서 pH 8.0으로 맞춘 것을 사용한 것이 50 mM EDTA(pH 8.0)와 0.6 M sodium acetate(pH 5.2)를 각각 사용한 것 보다 20 bp 길게 염기서열 분석이 되었다. Injection medium으로는 실험실에서 resin으로 탈 이온화 시킨 formamide보다 정제된 ABI formamide를 사용한 것이 보다 재현성 있게 reading length가 90 bp 더 길게 분석 되었으며, 4% PAGE gel 보다 3.6% PAGE gel을 사용한 것이 150 bp 더 길게 분석 되었다. Template 준비 시 chloroform으로 정제하고 2.5% DMSO를 첨가, sequencing 반응산물 정제 시 carrier의 pH를 8.0으로 맞춘 것을 이용, 그리고 ABI formamide와 3.6% gel 농도를 사용하는 최적의 조건으로 평균 700 bp, 85% score를 얻을 수 있었다.
Purpose : The purpose of this study was to survey on binocular fusion step and functional degree in synoptophore. Methods : we evaluated the binocular simultaneous, fusion and stereopsis conditions of pre and post phoria of 67 adult patients (male 50, female 17) from synoptophore and Vongrafe phoria method. Results : Average of phoria were -1.25±0.43b., phoria distributions were 1 to 7 prism. exophoria much more than esophoria. Esophoria distributions were 1 to 4 prism. Correlation of steropsis according to phoria degree, it was increased in process exophoria to esophoria (r = 0.409. p < 0.001). It were simultaneous perception post corrected phoria better than pre corrected phoria (t = 6.178, p = 1.479E-8). Fusion step were compared pre of corrected phoria to post of corrected phoria, simultaneous perception of pre corrected phoria were 2.05± 1.48°. fusion were 4.31±1.92°, stereopsis were 8.33±3.33°, simultaneous perception of post corrected phoria were 1.37±0.44°, fusion were 3.31±0.92°. stereopsis were 6.54±2.12°. It were fusion post of corrected phoria better than pre of corrected phoria (t = 6.178, p = 1.479E-8). Conclusions : ln these results. phoria degrees were small in synoptophore rather than in Vongrafe method. synoptophore method were evaluated functional fusion degree of vinocular vision, post of corrected phoria were improved simultaneous perception, fusion. stereopsis before pre of corrected phoria.
여름철 인천항과 부산항에 서식하는 대형저서동물군집의 구조를 파악하고자 하였다. 인천항의 9개 조사정점에서 출현한 대형저서동물 군집의 출현종수는 총 88종이었고, 서식밀도는 3,212개체 m-2, 생물량은 239 g m-2였다. 인천항내에서는 다모류의 Tharyx sp., C. setosa 등이 우점하였고, 외해에 위치한 정점에서는 이매패류인 M. senhousia, 다모류인 S. scutat 등이 우점하였다. 인천항에서 출현한 대형저서
Purpose : The purpose of this study was to survey on the wearing glasses and refractive errors in GP contact Jens user. Methods : we evaluated the refractive error and wearing conditions of the GP lens of 80 patients(male 18, female 62) from February 2006 to April 2007 on the Eye Clinic of K Hospital. Results : GP contact lens wearing time were daily over than lOhours 90%, 5 to 10hours 8.7%. 2 to 5hours 1.2%. Wearing time a day of have not glasses were 13.10±1.26 hours, wearing time a day of have glaases were 12.45±1.34hours. GP contact lens wearing time more Iong than wearing time have not glasses. Only contact lens wearers were 25% without eyeglass. difference of refractive error and spherical value of glasses were larger values of contact lens user than novice. Difference of refractive error and spherical value of glasses were larger vaJues of GPiens user in over one year than GPlens user in within one year. Conclusions : ln these results, majority of contact lens user were not recognized need corrected eyeglass. we knew that exchanged not glasses more Iong time GP contact lens users, accordingly, have not eyeglass were needed to educate thal contact lens wearer have to corrected eyeglass.
폴리비닐리덴풀루오라이드(Poly vinylidene fluoride, PVDF) 막을 고분자(Surface Modifying Macromolecules, SMM) 첨가제를 사용하여 표면 개질 하였다. 표면 개질된 PVDF 막의 제조는 0에서부터 2 wt%까지 SMM의 다양한 농도로 제조되었으며, 사용된 SMM으로써는 Zonyl BA-L을 이용하였다. 제조된 막을 이용하여 주사 전자 현미경법(SEM)과 접촉각 측정(Contact angle)을 하였고, 투과증발(Pervaporation)공정을 이용하여 물-에탄올 계의 분리실험을 통해 특성 평가를 하였다. 그 결과 SEM image를 통하여 SMM이 PVDF막 표면에 층을 형성하였음을 알 수 있었고, 접촉각은 기존의 PVDF 막 보다 SMM을 2 wt% 첨가하였을 때 8℃ 증가한 것으로 보아 소수성이 증가한 것을 알 수 있었다. 또한 물-에탄올 계에 대한 투과증발 실험은 다양한 조업온도별(50, 60, 70℃)로 수행하였으며, Zonyl의 함량이 PVDF 대비 1, 2 wt% 함유된 막을 사용하였으며 원액의 조성은 무게비로 물 10, 20, 50, 100%에 대하여 조사하였다. 물 : 에탄을 = 10 : 90 조성, 조업온도 50℃에서 선택도 287과 투과도 5.3 g/m 2 hr를 PVDF/2 wt% Zonyl BA-L 막이 보여주었다.
본 연구는 poly(vinyl alcohol) (PVA)와 가교제 poly(styrene sulfonic acid-co-maleic acid) (PSSA_MA)을 이용하여 제조된 막에 tetraethylorthosilicate (TEOS)를 도입하여 물-에탄올 계에 대한 투과증발 실험을 다양한 가교온도별(120~140℃), 조업온도별(25~70℃)로 수행하였다. TEOS의 함량은 PVA 대비 3, 5, 7 wt%를 사용하였으며, 원액의 조성은 무게비로 물 10, 20, 30 및 50%에 대하여 조사하였다. 물 에탄올 = 10 : 90 조성, 조업온도 50℃에서 선택도 1730과 투과도 16.3g/m2·hr를 PVA/7 wt% PSSA_MA/5 wt% TEOS 막이 보여 주었다.
DNA 결합 단백질 억제(Inhibitor of DNA binding protein) 또는 분화억제(Inhibitor of differentiation) 인자인 Id는 네 종류(Id1-4)가 있으며, 세포의 증식과 분화, 혈관 형성 및 세포자가사멸 등에 정 또는 부의 조절인자로서 널리 알려져 있다. 하지만 아직까지 번식생리 분야에서 이들 유전자들의 발현이나 기능에 관해 알려진 것은 거의 없다. 따라서 본 연구에서는 쥐 난소에서 난포의 발달에 따른 Id3 mRNA의 발현 양상을 살펴보고자 실시하였다. 쥐에게 PMSG 주사 후, 3, 6, 12, 24, 36 및 48시간째에 난소를 회수하여 고정, 탈수 및 파라핀 포매를 실시하였다. In situ hybridization 실험을 위하여 anti-sense와 sense Id3 cRNA 탐침자를 제작한 다음 난소 절편에 반응시켰다. 반응이 끝난 난소 절편은 NTB-2 유광제에 노출시킨 후 현상액에 반응시켰다. 모든 처리가 끝난 슬라이드는 H&E 염색을 실시한 다음 현미경하에서 hybridization 감도를 1+에서 4+로 구분하여 평가하였다. 난자에서는 Id3 mRNA 감도가 원시와 제1차 난포에서 ≥2+으로 확인되었으나, 제2차, 우성 및 배란전 난포에서는 1+ 이하로 관찰되었다. 한편, 과립막세포에서는 우성과 배란 전 난포에서 Id3 mRNA가 3+ 또는 4+로 강하게 발현되는 것을 확인하였다. 이상의 결과를 종합하여 보면, Id3 mRNA는 난포의 발단 단계 또는 난포세포에 따라 특이적으로 발현하는 것으로 보아 난포의 발달과 밀접한 연관이 있을 것으로 사료된다.