• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.127.1-127.1
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• 2011

In this paper, ZnO:Al thin films with c-axis preferred orientation were prepared on Soda lime glass substrates by RF magnetron sputtering technique. AZO thin film were prepared in order to clarify optimum conditions for growth of the thin film depending upon process, and then by changing a number of deposition conditions and substrate temperature conditions variously, structural and electrical characteristics were measured. For the manufacture of the AZO were vapor-deposited in the named order. It is well-known that post-annealing is an important method to improve crystal quality. For the annealing process, the dislocation nd other defects arise in the material and adsorption/decomposition occurs. The XRD patterns of the AZO films deposited with grey theory prediction design, annealed in a vacuum ambient($2.0{\times}10-3$Torr)at temperatures of 200, 300, 400 and $500^{\circ}C$ for a period of 30min. The diffraction patterns of all the films show the AZO films had a hexagonal wurtzite structure with a preferential orientation along the c-axis perpendicular to the substrate surface. As can be seen, the (002)peak intensities of the AZO films became more intense and sharper when the annealing temperature increased. On the other hand, When the annealing temperature was $500^{\circ}C$ the peak intensity decreased. The surface morphologies and surface toughness of films were examined by atomic force microscopy(AFM, XE-100, PSIA). Electrical resistivity, Gall mobility and carrier concentration were measured by Hall effect measuring system (HL5500PC, Accent optical Technology, USA). The optical absorption spectra of films in the ultraviolet-visibleinfrared( UV-Vis-IR) region were recorder by the UV spectrophotometer(U-3501, Hitachi, Japan). The resistivity, carrier concentration, and Hall mobility of ZnS deposited on glass substrate as a function of post-annealing.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.7 s.155
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• pp.1025-1033
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• 2006

Kenaf bast can be obtained by decortication of Kenaf stem. Kenaf fibers are much more rough than cotton fiber because they include impurities as pectin, lignin and hemicellulose besides cellulose. The purpose of this research is to investigate the distribution of kenaf fiber length and diameter during the processes of removing impurities. To remove pectin, kenaf bast was retted chemically. A half of the retted kenaf fiber bundle were scoured and bleached. The other half one were treated with $NaClO_2$ solution to remove lignin, and were treated with sodium hydroxide solution to remove hemicellulose. Four kinds of specimens that were obtained for investigating physical characteristics. Length and diameter of 100 fibers on each specimen was measured. The tensile strength of 100 fiber bundles were measured. And also the color values of them were measured with spectrocolorimeter. The length of retted kenaf fiber was 16.97cm. Then it decreased to 11.43cm after bleaching. Kenaf fiber bundles could be finer by chemical processes that remove non-cellulosic materials. The thickness of retted fiber was $132{\mu}m$. And after undergoing the chemical processes to remove non-cellulosic materials, the thickness of kenaf fiber became finer as $73{\mu}m$. Tensile strength of the retted kenaf fiber bundles was 11.37Mpa. The retted kenaf fiber lost their strength as 22.6% by bleaching and as 18.3% by treatment for removing lignin. The retted kenaf fiber showed low whiteness as 56.48 of L*value. After bleaching, the kenaf fibers have creamy white color and their whiteness got 90.02 of L*value. After the treatment for removing hemicellulose, the kenaf fibers also have creamy white color and their whiteness got L* value of 79.02.

• Reproductive and Developmental Biology
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• v.31 no.4
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• pp.267-272
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• 2007

Human embryonic stem (ES) cells are derived from the inner cell mass of the preimplantation embryo and have the capacity to differentiate into various types of cells in the body. Hence, these cells may potentially be an indefinite source of cells for cell therapy in various degenerative diseases including neuronal disorders. For clinical applications of human ES cells, directed differentiation of these cells would be necessary. The objective of this study is to develop the culture condition for the expansion of neural precursor cells derived from human ES cells. Human ES cells were able to differentiate into neural precursor cells upon a stepwise culture condition. Neural precursor cells were propagated up to 5000-fold in cell numbers over 12-week period of culture and evaluated for their characteristics. Expressions of sox1 and pax6 transcripts were dramatically up-regulated along the differentiation stages by RT-PCR analysis. In contrast, expressions of oct4 and nanog transcripts were completely disappeared in neural precursor cells. Expressions of nestin, pax6 and sox1 were also confirmed in neural precursor cells by immunocytochemical analysis. Upon differentiation, the expanded neural precursor cells differentiated into neurons, astrocytes, and oligodendrocytes. In immunocytochemical analysis, expressions of type III ${\beta}$-tubulin and MAP2ab were observed Presence of astrocytes and oligodendrocytes were also confirmed by expressions of GFAP and O4, respectively. Results of this study demonstrate the feasibility of long-term expansion of human ES cell-derived neural precursor cells in vitro, which can be a potential source of the cells for the treatment of neurodegenerative disorders.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.83-83
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• 2017

생체재료의 표면은 이식과 동시에 생체계면의 역할을 하게 되어, 일련의 생물학적 반응이 시작되고 진행되는 중요한 장소가 된다. 초기에 생체계면에서 일어나는 단백질 흡착이나 염증반응을 비롯한 생물학적 반응들은 궁극적으로 임플란트의 성패를 좌우할 만큼 중요하다. 골융합을 개선하기 위한 다른 방법으로 생체불활성의 타이타늄 (Ti)과 골조직의 능동적인 반응을 이루기 위해 생체활성 표면을 부여함으로서 계면에서의 골형성 반응을 증진시키는 방법이 이용된다. 생체불활성의 Ti과 Ti합금은 골조직과 직접적인 결합을 이루지 못하므로, 골조직과의 반응을 향상하기 위해 여러 종류의 생체활성 재료를 코팅하는 방법이 연구되어 왔고, 이 중 생체의 변화와 가장 유사한 하이드록시아파타이트 코팅이 가장 대중적인 방법으로 사용되었으며 이는 초기 골형성을 촉진하는 것으로 알려졌다. 치과용 임플란트의 표면형상과 화학조성이 골 융합에 영향을 미치는 가장 중요한 인자이므로 최근의 연구동향은 이들 두 가지 표면특성을 결합함으로서 결과적으로 최적의 골세포반응을 유도하고, 골융합 후 골조직과의 micromechanical interlocking에 의해 임플란트의 안정성에 중요한 역할을 하는 마이크론 단위의 표면조도와 표면 구조를 유지하면서, 부가적으로 골 조직 반응을 능동적으로 개선할 수 있는 생체활성 성분을 부여하여 골 융합에 상승효과를 이루기 위한 표면처리법에 관해 많은 연구가 요구되어지고 있다. 따라서 골을 구하는 원소인 망간과 실리콘으로 치환된 하이드록시아파타이트를 플라즈마 전해 산화법으로 코팅하여 세포와 잘 결합할 수 있는 표면을 제공함으로써 골 융합과 치유기간을 단축시킬 수 있을 것으로 사료된다. 실험방법은 시편은 치과 임플란트 제작 합금인 Ti-6Al-4V ELI disk (grade 5, Timet Co., USA; diameter, 10 mm, thickness, 3 mm)이며, calcium acetate monohydrate, calcium glycerophosphate, manganese(II) acetate tetrahydrate, sodium metasilicate을 설계조건에 따라 혼합 제조된 전해질 용액을 이용하여 플라즈마 전해 산화법으로 표면 코팅을 실시하였다. 각 시편의 플라즈마 전해시 전압은 280V로 인가하였고, 전류밀도는 70mA로 정전류를 공급하여 해당 인가전압 도달 후 3분 동안 정전압 방식을 유지하였다. 코팅된 피막 표면을 주사전자현미경과 X-선 회절분석을 통하여 미세구조 및 결정상을 관찰하였다. 또한 코팅된 표면의 생체활성 평가는 정량적으로 평가하기 위해 동전위시험과 AC 임피던스를 통하여 시행하였다. 분극거동을 확인하기 위해 potentiostat (Model PARSTAT 2273, EG&G, USA)을 이용하여 구강 내 환경과 유사한 $36.5{\pm}1^{\circ}C$의 0.9 wt.% NaCl에서 실시하였다. 전기화학적 부식 거동은 potentiodynamic 방법으로 조사하였고 인가전위는 -1500 mV에서 2000 mV까지 분당 1.67 mV/min 의 주사속도로 인가하여 시험을 수행하였다. 임피던스 측정은 potentiostat (Model PARSTAT 2273, EG&G, USA)을 이용하였으며, 측정에 사용한 주파수 영역은 10mHz ~ 100kHz 까지의 범위로 하여 조사하였고 ZSimWin(Princeton applied Research, USA) 소프트웨어를 사용하여 용액의 저항, 분극 저항 값을 산출하였다. 망간의 함량이 증가할수록 불규칙한 기공을 보였으며, 실리콘은 $TiO_2$ 산화막 형성을 저해하는 경향을 확인할 수 있었다. 단독으로 표면을 처리한 경우보다 두 가지 원소를 이용해 복합 표면처리를 시행한 경우가 내식성이 좋아 임플란트과의 골 유착에 긍정적인 영향을 미칠 것으로 사료된다.

• Applied Microscopy
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• v.41 no.2
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• pp.139-145
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• 2011

Parthenocissus tricuspidata is an epiphyte that lacks a main axial stem, but develops adhesive disks along the stem for climbing support. In this study, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were utilized to examine the brick wall surface and the adhesive disks of P. tricuspidata that attached to the surface successfully. The study was mainly focused the outermost layers of both structures before and after adhesion to find out whether there has been some structural and/or physical interactions between the two. The adhesive disks adhered firmly to the brick wall by secreting adhesive materials that help them for a tight attachment to the surface. The rough wall surface appeared facilitating better attachment of the adhesive disks by infiltrating the materials into those spaces leading to some degree of interactions at the interface. EDS analysis on the outermost layers of the adhesive disks that were separated from the substrates was also consistent with the SEM data on the interaction between the adhesive disks and the substrate surface. EDS analysis of the brick wall surface and the adhesive disks demonstrated similar elements of O, Si, Fe, Al, K, Mg, and Na in their components.

• Tuberculosis and Respiratory Diseases
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• v.59 no.4
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• pp.432-435
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• 2005

An 82-year-old female non-smoker with a history of hypertension presented with increasing dyspnea, cough and some purulent sputum without fever. Upon admission, the patient was in a distressed condition. Auscultation revealed diminished breath sounds with no rales over the right lung. An examination of the heart revealed a regular rhythm and a systolic murmur radiating from the apex of the heart. There was no pitting edema in the lower extremities. The blood tests showed mild leukocytosis and an increased C-reactive protein level. The $O_2$ saturation was 98 % whilst breathing room air. The electrocardiogram demonstrated sinus tachycardia. The chest radiograph showed a moderate cardiomegaly, right lobe infiltrates, and blunting of the both costophrenic sulcus suggesting a small pleural effusion. Three days after admission, the symptoms became slightly aggravated despite being treated with empirical antibiotics for presumed community-acquired pneumonia. Transthoracic color Doppler echocardiography indicated an ejection fraction of 48 %, mild left ventricular enlargement, and moderate left atrial enlargement resulting in severe mitral regurgitation. The clinical symptoms and right pulmonary edema resolved quickly with intravenous furosemide treatment.

• Elastomers and Composites
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• v.45 no.2
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• pp.112-121
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• 2010

In this study, styrene butadiene rubber(SBR)/organoclay nanocomposites were manufactured using the latex method with 3-aminopropyltriethoxysilane(APTES) as a modifier. The X-ray diffraction(XRD), transmission electron microscopy(TEM) images, Fourier transform infrared(FTIR) spectroscopy, swelling ratio and mechanical properties were measured in order to study the interaction between filler and rubber according to the mixing temperature in the internal mixer. In the case of SBR/APTES-MMT compounds, the dispersion of the silicates within the rubber matrix was enhanced, and thereby, the mechanical properties were improved. The characteristic bands of Si-O-C in APTES disappeared after hydrolysis reaction in the MMT-suspension solution and the peak of hydroxyl group was increased. Therefore the formation of chemical bonds between the hydroxyl group generated from APTES on the silicate surface and the ethoxy group of bis(triethoxysilylpropyl) tetrasulfide(TESPT) was possible. Consequently, the 300% modulus of SBR/APTES-MMT compounds was further improved in the case of using TESPT as a coupling agent. However, the silanization reaction between APTES and TESPT was not affected significantly according to the increase of mixing temperature in the internal mixer.

• Journal of Microbiology
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• v.44 no.2
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• pp.192-199
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• 2006

Pseudomonas putida KL47 is a natural isolate that assimilates benzene, 1-alkylbenzene $(C_1-C_4)$, biphenyl, p-cumate, and p-cymene. The genetic background of strain KL47 underlying the broad range of growth substrates was examined. It was found that the cym and cmt operons are constitutively expressed due to a lack of the cymR gene, and the tod operon is still inducible by toluene and biphenyl. The entire array of gene clusters responsible for the catabolism of toluene and p-cymene/p-cumate has been cloned in a cosmid vector, pLAFR3, and were named pEK6 and pEK27, respectively. The two inserts overlap one another and the nucleotide sequence (42,505 bp) comprising the cym, cmt, and tod operons and its flanking genes in KL47 are almost identical (>99 %) to those of P. putida F1. In the cloned DNA fragment, two genes with unknown functions, labeled cymZ and cmtR, were newly identified and show high sequence homology to dienelactone hydrolase and CymR proteins, respectively. The cmtR gene was identified in the place of the cmtI gene of previous annotation. Western blot analysis showed that, in strains F1 and KL47, the todT gene is not expressed during growth on Luria Bertani medium. In minimal basal salt medium, expression of the todT gene is inducible by toluene, but not by biphenyl in strain F1; however, it is constantly expressed in strain KL47, indicating that high levels of expression of the todST genes with one amino acid substitution in TodS might provide strain KL47 with a means of adaptation of the tod catabolic operon to various aromatic hydrocarbons.

• Journal of Acupuncture Research
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• v.22 no.1
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• pp.109-115
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• 2005

Objective : The purpose of this case is to report the improvement after treatment about a patient with meralgia paresthetica. Methods : We treated the patient with acupuncture therapy and Herbal medication from 11th October 2004 to 15th October 2004 by evaluating femoral function with VAS score and R.O.M of femur joint. Results : After 5 times of treatment, this patient achieved excellent outcome following the technique, showing that clinical symptom as like heating sense, edema and pain was disappeared, VAS changed from 10 to 1 and there was no limitation of ROM of femur. Conclusions : Meralgia paresthetica is a symptom complex that includes numbness, paresthesias, and pain in the anterolateral thigh, which may result from either an entrapment neuropathy or a neuroma of the lateral femoral cutaneous nerve(LFCN). Oriental medical treatment for meralgia paresthetica resulted in satisfactory results by diminishing the symptoms progressively during the five days of treatment. Differential diagnosis was based on careful physical examination. More research of meralgia paresthetica is needed.

• Food Science and Preservation
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• v.13 no.5
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• pp.603-610
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• 2006

Korean traditional soy paste (Doenjang) was fermented using Meju prepared by the culture of wild microorganisms in steamed soy beans. During the fermentation, changes in the physicochemical and several functional properties were monitored. Total acidity and amino acidity increased from 0.09 to 0.96, and 2.24% to 3.28% respectively, Amylase and protease activities increased and showed the maximal level after 60 days of fermentation, which were 4.03 and 7.29 units/ml, respectively. However, both enzyme activities decreased after then. The inhibitory activities against tyrosinase and angiotensin converting enzyme increased and reached 20.57 and 38.18% respectively. Antimutagenic activities against N-methyl-N'-nitro-N-nitiosoguanidine and 4-nitro-O-phenylenediamine (NPD) increased for 90 days and roached 70.21 and 60.01% in S. enterica serovar Typhimurium TA100, respectively. Against NPD and 4-nitroquinoline-1-oxide, the antimutagenic activities also increased and reached 50.91 and 46.35% in the strain TA98, respectively.