Nicotine이 배양된 정상 인체 멜라닌세포의 멜라닌화에 미치는 영향

최천필,김영일,이진우,이무형 경희대학교 동서의학연구소 2006 東西醫學硏究所 論文集 Vol.2006 No.-

Nicotine, the active ingredient of tobacco, causes increased platelet aggregation, endothelial cell damage and alterations in prostacyclin and thromboxane metabolism. Skin changes with nicotine include brown pigmentary staining of hands and nails, leg ulcers, cyanosis, decreased skin temperature and other signs of arterial insufficiency. However, the effect of nicotine on melanization is not well established. The purpose of this study is to evaluate the effect of nicotine on melanization in cultured normal human melanocytes. In order to evaluate non-cytotoxic dose of nicotine, we exposed various concentrations (0.01, 0.1, 1, 10, 100, and 1000 μg/ml) of nicotine to melanocytes and examined cell cytotoxicity using MTT assay. There was no cytotoxicity below 0.1 μg/ml of nicotine. After exposure to 0.1μg/ml nicotine on cultured normal human melanocytes, we investigated the effects of nicotine on the expression of tyrosinase (TYR), tyrosinase-related protein 1 (TYRP1), DOPAchrome tautomerase (DCT) at the protein levels in human skin melanocytes. There was no significant difference in the expression of TYR, TYRP1, and DCT protein after treatment with nicotine compared to the untreated control. These results suggest that short-term nicotine exposure had no direct melanogenic effect, in vitro.

窒素質肥科의 基追肥 施用時期가 이타리안라이그라스의 生育 및 靑草收量과 養分組成에 미치는 影響

崔洙日,崔亨松,陳星桂 又石大學校 1990 論文集 Vol.12 No.-

本 硏究는 冬季休閑畓을 活用한 이타리안 라이그라스의 栽培에 알맞은 窒素質肥料의 基·追肥 施用適期를 알고자 遂行하였던 바 다음과 같은 結果를 얻었다. 1. 窒素基肥施用時期가 늦어질수록 越 草長의 伸長短縮과 靑草收量을 感收시켰고 組蛋白質, 組脂肪, 組灰粉의 含量도 적어 飼料의 質을 低下시켰으며 또한 越冬期 枯死莖 被害와 越冬後의 靑草收量도 減小시켰다. 2. 窒素質肥料의 追肥施用適期 試驗에서도 追肥施用適期가 늦어질수록 生育量 및 追肥施用適期 減小와 節間을 伸長시켰으며 組蛋, 白質, 組脂肪 含量도 적었다. 3. 窒素質肥料의 基追肥 施用適期는 基肥는 播種當日, 追肥는 生育再生後 10日頃이었다. This experiment was carried out to study the effects of different application times on the nitrogen fertilizer, the fresh matter yield and feed efficiency of Italianryegrass under winter cropping on drained paddy field. Plant height, fresh matter yield and content of organic nutrient were decreased. According as the application times of top basal dressing on the nitrogen were late. In the experiment of the application times of top dressing on the nitrogen times of top wintering. Agronomic characters, fresh matter yield, crude protein, crude fat and crude were decreased. According as thd application times of top dressing on the nitrogen fertilizer were late. The optimum application time of nitrogen fertilizer was sowing date in basal dressing and was 10 days after regrowth in top dressing.

양성 및 음성 정신분열증 환자의 시각적주의폭에 관한 연구

최정인,이형영,윤진상 大韓神經精神醫學會 1988 신경정신의학 Vol.27 No.5

This study was performed to compare the visual attention span among three groups of 22 negative schizophrenics, 29 positive schizophrenics and 30 normal controls. The narrowing and broadening of attention span were tested by comparing correct recognition responses of peripheral visual stimulus. The results are as follows : 1) There was a significant difference in the total number of correct recognition responses among three groups; In controls, the total number of the correct recognition responses was highest and this was followed by positive schizophrenics(P<0.01). The number of the correct recognition responses was higher in larger stimulus size than in small stimulus size in all three groups(P<0.01). 2) Comparing groups and stimulus size; there was no significant difference in large stimulus size. In small stimulus size, there was significant difference between postivive schizophrenics and controls(P<0.05), between negative schizophrenics and controls(P<0.01), and between negative schizophrenics and positive schizophrenics(P<0.01). 3) Comparing groups and display angle, there was no significant difference in display angle 2˚ among three groups, while there was significant difference in display angle 12˚ between negative schizophrenics and controls(P<0.01), and significant difference in display angle 25˚ between negative schizophrenics and controls and between negative schizophrenics and positive schizophrenics(P<0.01), respectively. In summary, these results suggest that negative schizophrenics, unlike postive schizophrenics and controls, are only able to recognize large peripheral stimulus within a narrow display angle, because of narrowing of attention span.

TiN 코팅이 전기도금한 교정용 스테인레스스틸 선재의 세포독성에 미치는 영향

최준규,조진형,황현식,박병주 전남대학교 치의학연구소 2003 구강과학 Vol.15 No.4

This study was performed to investigate whether TiN coating could reduce the cytotoxicity of electroplated orthodontic stainless steel wire which had been known to be cytotoxic. Nickel plating was done on stainless steel wire using a electroplating technique. Some of the electroplated wires were coated by TiN film and 4 groups of specimen were prepared (Non-coated electroplated wire, TiN coated electroplated wire, Titanium which was known to have no cytotoxicity, Copper which was known to have high cytotoxicity). Each wire was incubated for 72 hours on the medium. The release of the metal ion was measured by ICP-AES. The incubated medium was diluted 75 %, 50%, 25 % and added on each microplate with Balb/c 3T3 mouse fibroblast for MTT analysis and compared with medium only. Through the measuring of the change in absorbency value of each wire group and the difference of absorbency value according to change of dilution, following results were obtained. 1. The results of ICP-AES analysis showed that lots of nickel ions were isolated from non-coated wires but not isolated from TiN coated wires. 2. The inverted microscope showed that there was a decrease in cell count in non-coated wires but no significant change in TiN coated wires. 3. The results of MTT analysis showed that there was no difference in the absorbency value between TiN coated wires and medium and between titanium and medium but the absorbency value of non-coated wires and copper were lower than that of medium only at all dilution and showed statistically significant differences(p<0.001). 4. Assessment as per ISO 10993, part 5, non-coated wires and copper investigated corresponded to "moderately cytotoxic" and "highly cytotoxic" ; whereas titanium and TiN coated wires were alloted to "non-cytotoxic". The results of the present study indicate that the cytotoxicity of the electroplated orthodontic wire can be changed from "moderately cytotoxic" to "nontoxic" by TiN coating and electroplated wire can be used clinically without the concern of cytotoxicity.

[논문]실험시설 기초의 진동사용성 분석

최형석,전법규,김남식,정진환 釜山大學校生産技術硏究所 2007 生産技術硏究所論文集 Vol.66 No.-

건물에 작용하는 진동하중은 구조물 자체의 성능에 영향을 미칠 뿐만 아니라 거주하는 사람이나 작업기계 동에 나쁜 영향을 가져올 수 있다. 본 연구에서는 이러한 진동에 대한 영향을 평가하는 국내외의 기준에 대하여 고찰하고 다양한 하중과 주파수 대역에서 실험이 가능한 대형지진모사 실험센터에 대한 진동영향 평가를 수행하여 사용성 저하 여부를 확인하였다.

배열형 전력 MOSFET의 설계 및 제작

김진형,최연익,정상구,박찬광,김충기,성만영 亞洲大學校 1987 論文集 Vol.10 No.-

In this paper, the design of the array type power MOSFETs is discussed in terms of on-resistance, breakdown voltage, placement of FLRs(field limiting ring) and threshold voltage. Also, 9-cell(square-on square grid) VDMOSs are fabricated to confirm the feasibility of the design method. Existence of optimum p-well spacing for minimum on-resistance, which is anticipated by the theoretical results is confirmed by the experiment of the fabricated power MOSFETs. Breakdown voltage of power MOSFET is upgraded by using two FLR's and their optimum placement is determined from the experimental results of the diodes with FLRs. The threshold voltage is controlled by the ion implantation within the design specification. Experimental results are in good agreement with the design specification. Experimental results are in good agreement with the design values. Characteristics of the fabricated power MOSFETs are 190Ω in on-resistance, 270V in breakdown voltage and 2.9V in thershold voltage.

하지방사통을 동반한 성인 협부결손성 요추전방전위증의 후방요추간유합술 및 추경나사고정술후 추적결과

최철,김근수,최하영,김철진,김형일,이정청 대한신경외과학회 1999 Journal of Korean neurosurgical society Vol.28 No.4

중추성 요붕증이 동반된 랑게르한스 세포 조직구증 1예

김진호,문준성,문선중,이지은,최재원,은미정,천경아,조인호,윤지성,원규장,이경희 신덕섭,이형우 영남대학교 의과대학 2005 Yeungnam University Journal of Medicine Vol.22 No.2

Central diabetes insipidus (DI) is a syndrome characterized by thirst, polydipsia and polyuria. Langerhans cell histiocytosis is one of the etiologies of DI. Recently we experienced a central DI associated with Langerhans cell histiocytosis. The 44 years old female patient complained right hip pain polydipsia and polyuria. We carried out water deprivation test. After vasopressin injection, urine osmotic pressure was increased form 109mOsmol/Kg to 327mOsmol/Kg (300%). Brain MRI showed a thickened pituitary stalk and at hot bone CT.CT guided biopsy revealed abnormal histiocytes proliferation and abundant lymphocytes, The final diagnosis was central DI associated with systemic Langerhans cell histiocytosis invading hip bone, L-spine and pituitary stalk. Desmopressin and etoposide chemotherapy were performed to the patient.

승온시 Si₂H가스 주입을 이용한 저온 Si 에피택시에 관한 연구

金亨駿,申東勳,崔圭鎭,金東玄 弘益大學校 科學技術硏究所 1998 科學技術硏究論文集 Vol.9 No.2

In this study, we studied on the low temperature Si epitaxy growth for Si epitaxial growth temperature below 650。C. Usually, the Si epitaxy films by chemical vapor deposition are crystallized to polycrystalline films due to a formation of SiO₂layer at the epitaxial Si/Si substrates interfaces. Formation of SiO₂layer on Si surface can be effectively prevented by flowing the Si₂H?? gas during the heating-up procedure for Si deposition. In this way, Si epitaxial layer onto (100) Si substrates was grown epitaxial layer during the post-deposition heat treatments. The suppression of surface BIO₂can be explained in terms of adsorption of SiH?? adspecies, instead of oxygen from residual gases in the reactors, to Si surfaces after desorption of hydrogen from H-passivated Si surfaces. Employing Si₂H?? flowing and epitaxial growth, high-quality epitaxial Si layer was the low temperature below 650。C without conventional high temperature cleaning procedures. And the crystallinity of epitaxial layer measured as deposition conditions using ultraviolet reflectance. AS this results, we could be aquaired process temperature region for high-quality low temperature Si epitaxial growth.

전처리 환경조건 변화에 의한 국내산 크라프트지의 물리적 특성 평가

김형진,최원정,최형기 한국공업화학회 2003 응용화학 Vol.7 No.2

This study was carried out in order to evaluate the physical properties of domestic kraft paper according to the changes of pre-conditioning environmental conditions. For the testing of physical and mechanical strength of paper, the specimens must be preconditioned under the specific environmental factors, such as temperature and RH. Recently, Korean Industrial Standard is revising for the coincidence with International Standard Organization. In this study, the physical and mechanical properties of kraft paper were considered by the two kinds of standard, KS M7011 and ISO 187, and evaluated by the linear regression equation.