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        Quantitative comparison of mRNA expression of glucosyltransferase(GTF) between xylitol-resistant(X^(R)) and xylitol-sensitive(X^(s)) mutans streptococci

        Kim, Chong-Chul,Lee, Mi-Na,Kim, Young-Jae,Lee, Sung-Hoon 大韓小兒齒科學會 2006 大韓小兒齒科學會誌 Vol.33 No.1

        Since the long-term exposure of mutans streptococci to xylitol is known to select for xylitol-resistant(X^(R)) natural mutants, the occurrence and survival of such X^(R) strains were performed in batch culture methods. The aim of the study was to compare the differentiation and quantification of mRNA expression of the gtf genes of X^(R) and X^(S) mutans streptococci. Using a real-time reverse-transcription polymerase chain reaction, the expression of each gtf was determined. In X^(R) strains, the relative levels of transcription of gtfB and gtfC were decreased while that of gtfD was increased, suggesting the presence of independent promoters. It also suggested that mutation related to production of glucosyltransferase occurred under the exposure of xylitol could explain the caries-preventive mechanisms of xylitol. 자일리톨에 장기간 노출된 mutans streptococci는 자일리톨에 내성이 발현되어 자일리톨 내성균주가 생성된다고 알려져 있다. 본 연구의 목적은 mutans streptococci에서 자일리톨 내성균주와 감성균주의 gtf 유전자 발현량을 각각의 유전자별로 정량적으로 분석하고 비교하는 것이다. 실시간 역전사 중합효소연쇄반응법을 이용하여 각각의 gtf 발현을 조사한 결과 gtfD는 증가한 반면. gtfB와 gtfC는 감소하였는데 이는 각 유전자의 독립된 조절기전이 존재함을 보여주는 것이다. 또한 자일리톨에 노출된 mutans streptococci에서의 glucosyltransferase와 연관된 유전자변형이 자일리톨의 치아우식증 예방효과의 작용기전 중 하나임을 알 수 있었다.

      • KCI등재
      • KCI등재후보

        Apoptotic Effect of Co-treatment with Chios Gum Mastic and HS-1200 on G361 Human Melanoma Cell Line

        Young-Joo Hur,Young-Ki Kim,Hyun-Ho Kwak,Gyoo-Cheon Kim,Seung-Eun Lee,In-Ryoung Kim,Chul-Hoon Kim1,Bong-Soo Park 대한해부학회 2009 Anatomy & Cell Biology Vol.42 No.2

        Chios gum mastic (CGM) is a resinous exudate obtained from the stem and the main leaves of Pistacia lenticulus tree native to Mediterranean areas. Recently it reported that CGM induce apoptosis in a few cancer cells in vitro. Bile acids and their synthetic derivatives induced apoptosis in various kinds of cancer cells and anticancer effects. It has been reported that the synthetic chenodeoxycholic acid (CDCA) derivatives showed apoptosis-inducing activity on various cancer cells in vitro. This study was undertaken to investigate the synergistic apoptotic effect of cotreatment with a natural product, CGM and a CDCA derivative, HS-1200 on G361 human melanoma cells. To investigate whether the co-treatment of CGM and HS-1200 compared with each single treatment efficiently reduced the viability of G361 cells, MTT assay was conducted. To investigate augmentation of apoptosis in G631 cells co-treated with CGM and HS-1200, DNA electrophoresis, Hoechst staining, proteasome activity assay, flow cytometry, Westen blot analyses, immunofluorescent staining and confocal microscopy were performed. In this study, G361 cells co-treated with CGM and HS-1200 showed several lines of apoptotic manifestation such as nuclear condensations, DNA fragmentation, the reduction of MMP and proteasome activity, the decrease of DNA content, the release of cytochrome c into cytosol, the translocation of AIF and DFF40 (CAD) onto nuclei, activation of caspase-9, caspase-3, PARP and DFF45 (ICAD), and up-regulation of Bax whereas each single treated G361 cells did not. Although the single treatment of 40 μg/mL CGM or 25 μM HS-1200 for 24 hrs did not induce apoptosis, the co-treatment of them induced prominently apoptosis. Therefore, combination therapy of CGM and HS-1200 could be considered, in the future, as an alternative therapeutic strategy for human melanoma.

      • KCI등재
      • 음낭외상시 고환파열에 대한 초음파 검사의 진단적 유용성

        김경영,한동준,신대은,노준,문형윤,임동훈,김철성,박성운 朝鮮大學校 附設 醫學硏究所 2007 The Medical Journal of Chosun University Vol.32 No.3

        Purpose: We determined the use of scrotal ultrasonography in the initial diagnosis and management of testicular injuries due to blunt scrotal trauma. Mateiials and Methods: We reviewed 54 patients of scrotal trauma in the last 8 years. Forty patients were evaluated by ultrasonography preoperatively. A heterogeneous echo pattern of the testicular parenchyma with loss of oval shape, contour definition was the basis for diagnosis of testicular rupture. Among them, 33 cases underwent scrotal exploration and 7 cases were managed conservatively. The remaining 14 patients were evaluated only by physical examination, 8 patients of them were explored immediately because of suspicious testicular mpture. The accuracy of ultrasonography were determined by comparing radiographic interpretations with intraoperative findings. Results: Among the 33 patients who were evaluated by ultrasonography and explored immediately, there were 26 suspected testicular ruptures on ultrasonography. Surgical exploration revealed testicular rupture in 23 and simple hematoma in 10. The testicular rupture was correctly diagnosed by ultrasonography in the 22 cases, and there were 4 false-positive and 1 false-negative diagnoses of testicular rupture. The sensivity and specificity for the diagnosis of testicular rupture are 96% and 60%, and the positive and negative predictive values are 85% and 86%, respectively, Conclusions: Scrotal ultrasonography, with the main radiographic finding of a heterogeneous echo pattern of the testicular parenchyma with loss of oval shape, contour definition, is highly sensitive on the diagnosis of testicular rupture. And it increases the salvage rate for testicular rupture with preservation of the testicular function and prevents delayed complications of chronic pain, atrophy and orchiectomy associated with missed testicular rupture.

      • KCI등재

        설측 브라켓 부착을 위한 기준평면 설정에 관한 3차원 유한요소법적 연구

        김선화,박수병,양훈철 대한치과교정학회 2006 대한치과교정학회지 Vol.36 No.1

        교정치료 영역에서 성인들의 심미적인 요구도가 증가되면서 설측 교정치료는 여러 가지 단점에도 불구하고, 가장 심미적이라는 이유로 많은 주목을 받아왔지만 실제 치아이동을 결정지을 수 있는 브라켓을 부착하는 기준평면의 위치에 대해서는 거의 보고된 바가 없다. 이에 본 연구는 실제 브라켓이 부착되는 평면의 상하 평행이동이나 기울기 변화에 따라 치아이동 양상이 어떻게 변화되는지 알아보고, 바람직한 전치부 치체이동을 얻기 위해서 힘의 적용점을 어디에 두어야 하는지, 그리고 전치부에 어느 정도 모멘트를 부여해야 하는지 알아보고자 3차원 유한요소법을 이용하여 치아 변위 및 응력분포를 비교 분석하였다. 실험 결과 설측 브라켓 부착평면을 치은연쪽으로 평행이동 혹은 회전이동 시키고 견인하였을 경우, 절단연쪽으로 이동시켰을 때와 비교했을 때 비조절성 설측 경사이동이 감소하기는 하였으나 상하악 전치부 치아들의 설측경사 양상은 지속되었으며, 이러한 양상은 견치 브라켓의 hook 길이를 증가시켜도 계속 나타났다. 이와는 달리 설측 중심평면에 브라켓을 부착하고 각 치아별로 모멘트를 부여하였을 경우 설측 방향으로 개개 치아들의 치체이동이 발생하여 설측 교정치료 시 효과적인 전치부 치아의 후방견인이 가능함을 알 수 있었다. This study was performed to investigate the location of the ideal bracket positioning plane in lingual orthodontics using the three-dimensional finite element method. Displacement of the anterior teeth were evaluated according to the vertical and the angular movements of the bracket positioning plane. To achieve the ideal movement of anterior teeth in the lingual central plane, the location of the force application point and the amount of the moment applied to the four incisors were evaluated. As the bracket positioning plane was moved parallel toward the incisal edge, uncontrolled tipping and extrusion of the maxillary and the mandibular incisors were increased. But lingual tipping of the crown was decreased in the maxillary and the mandibular canines. As the bracket positioning plane was inclined toward the incisal edge, lingual tipping was increased in the 6 anterior teeth and extrusion of incisors and intrusion of the canine was also increased. As the retraction hook of the canine bracket was elongated, lingual tipping and extrusion of the central incisor and mesial movement and extrusion of the lateral incisor were increased. In the canine, mesial and labial movements of the crown were increased. When the moment was applied to the 4 incisors of the maxillary and the mandibular arch in the lingual central plane, 280 gf-mm in the maxillary central incisor, 500 gf-mm in the maxillary lateral incisor, 170 gf-mm in the mandibular central incisor and 370 gf-mm in the mandibular lateral incisor produced bodily movement of the individual tooth.

      • CO_2 레이저빔을 이용한 TFT-LCD 도광판의 패턴 제작에 관한 연구

        김경동,백창일,송철기,안성훈 경상대학교 생산기술연구소 2002 工學硏究院論文集 Vol.2 No.-

        A light guide panel is an element of the LCD backlight module that is often used for the display of compact electronic devices. In this study, a laser marking system is proposed to fabricate light guide panel, which can replace other manufacturing methods such as silk printing, stamping, or v-cutting methods. The objective of this research is to evaluate the process parameters of the laser marking system. Light guide patterns were marked with a 50W CO_2 laser(CW) to understand the effects of average power and scanning speed on the geometry and quality of groove pattern. The width of the fabricated grooves increases with increasing laser power and decreasing scan speed. In order to analyze surface characteristics and optical properties(luminance, uniformity), SEM photography and BM7(luminance measuring system) were used. As a result, the optimal conditions of the process parameters that provide high luminance was obtained.

      • KCI등재후보

        분절호선법으로 상하악 절치부 압하 시 순측경사도가 미치는 영향에 관한 3차원 유한요소법적 연구

        김동우,양훈철,김기태,김성식,손우성 대한치과교정학회 2003 대한치과교정학회지 Vol.33 No.4

        본 연구는 상하악 절치부의 압하를 도모하기 위한 장치의 하나인 분절호선장치를 사용하여 절치부의 순측경사에 따른 저항중심의 위치와 변화양상, 그리고 치축경사 개선과 압하를 동시에 이루기 위해 필요한 최소 후방 견인력의 크기 및 변화양상을 알아보기 위하여 3차원 유한요소법을 이용하여 시행되었으며 다음과 같은 결론을 얻었다. 1. 치축 경사도의 변화에 따른 상악 절치부 저항중심은 1) 정상 치축경사를 가진 경우에서 측절치 브라켓 원심면 후방 6mm에 위치하였다. 2) 순측경사가 10˚ 증가된 경우에서 측절치 브라켓의 원심면 후방 9mm에 위치하였다. 3) 순측경사가 20˚ 증가된 경우에서 측절치 브라켓 원심면 후방 12mm에 위치하였다. 4) 순측경사가 30˚ 증가된 경우에서 측절치 브라켓 원심면 후방 16mm에 위치하였다. 2. 치축 경사도의 변화에 따른 하악 절치부 저항중심은 1) 정상 치축경사를 가진 경우에서 측절치 브라켓 원심면 후방 10mm에 위치하였다. 2) 순측경사가 10˚ 증가된 경우에서 측절치 브라켓 원심면 후방 13mm에 위치하였다. 3) 순측경사가 20˚ 증가된 경우에서 측절치 브라켓 원심면 후방 15mm에 위치하였다. 4) 순측경사가 30˚ 증가된 경우에서 측절치 브라켓 원심면 후방 18mm에 위치하였다. 3. 응력 분포 양상은 1) 각 저항중심에서 압하력을 가한 경우에 치주인대에 균일한 압축응력을 나타내었다. 2) 후방 견인력을 동시에 적용한 경우에 순측경사가 증가할수록 응력분포 양상이 복잡해지는 양상을 보였다. 4. 상하악 절치부가 20˚까지 순측경사된 경우에서 pure intrusion을 위하여 필요한 후방 견인력의 크기도 증가하였다. This study was designed to investigate the position of anteroposterior center of resistance for genuine intrusion and the mode of change of the minimum distal force for simultanous intrusion and retraction of the upper and lower incisors according to the increase of labial inclination. For this purpose, we used the three-piece intrusion arch appliance and three-dimensional finite element models of upper and lower incisors. 1. Positions of the center of resistance in upper incisors according to the increase of the labial inclination were as follows; 1) In normal inclination situation, the center of resistance was located in 6mm behind the distal surface of the lateral incisor bracket. 2) In 10˚ increase of the labial inclination situation, the center of resistance was located in 9mm behind the distal surface of the lateral incisor bracket. 3) In 20˚ increase of the labial inclination situation, the center of resistance was located in 12m behind the distal surface of the lateral incisor bracket. 4) In 30˚ increase of the labial inclination situation, the center of resistance was located in 16m behind the distal surface of the lateral incisor bracket. 2. Positions of the center of resistance in lower incisors according to the increase of the labial inclination were as follows; 1) In normal inclination situation, the center of resistance was located in 10mm behind the distal surface of the lateral incisor bracket. 2) In 10˚ increase of the labial inclination situation, the center of resistance was located in 13mm behind the distal surface of the lateral incisor bracket. 3) In 20˚ increase of the labial inclination situation, the center of resistance was located in 15m behind the distal surface of the lateral incisor bracket. 4) In 30˚ increase of the labial inclination situation, the center of resistance was located in 18m behind the distal surface of the lateral incisor bracket. 3. The patterns of stress distribution were as follows; 1) There were even compressive stresses in and periodontal ligament when intrusion force was applied through determined center of resistance. 2) There were gradual increase of complexity in compressive stress distribution pattern with increase of the labial inclination when intrusion and retraction force were applied simultaneously. 4. With increase of the labial inclination of the upper and lower incisors, the position of the center of resistance moved posteriorly. And the distal force for pure intrusion was increased until 20˚ increase of the labial inclination.

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