• 제목/요약/키워드: breakage

검색결과 830건 처리시간 0.028초

Effects of Ixeris dentata Extracts on the Genotoxicity Induced by Gamma Irradiation in Rats

  • Kim, Jin Kyu;Woo, Hyun Jung;Kim, Ji Hyang;Yoon, Yang Dal
    • 환경생물
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    • 제22권4호
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    • pp.543-549
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    • 2004
  • Ixeris dentata is a typical oriental herb. It is a widely distributed perennial in Korea, Japan and China, which belongs to the Compositae Family. The whole plant of I. dentata has been used for the treatment of pneumonia, contusion, tumor and hepatitis. It has also been used for the treatment of allergic diseases as a folk therapy in Korea. I. dentata is known to have aliphatics, triterpenoids and sesquiterpene glycosides in its composition. The present study was designed to explore the protective effects of water- and ethanol- extracts from I. dentata on irradiated rodents. For oral administration (twice per day), the extractive powder of I. dentata and the positive control (ascorbic acid) were dissolved at a concentration of 0.5 and 250mg $ml^{-1}$ in saline, respectively. Thirty days after irradiation, the ratio of the weight of the testis to the body weight was lower than 50% in the radiation groups than the control group. The ALP concentrations in the group treated with the water-extracts of the leaf were $79.68\pm{1.39%}$ (p<0.05) of those of the radiation control. Both of the SGOT and SGPT in the group treated with the ethanol-extract of the root were $72.68\pm{0.95}\;and\;77.87\pm{5.74}$ (p<0.05) of those of the radiation control, respectively. The levels of DNA damage induced by gamma radiation decreased in the experimental group to which the extracts of I. dentata were administered before irradiation. In conclusion, these results indicate that the extracts of I. dentata have an excellent ability to reduce the radicals and they have a protective effect on DNA breakage caused by radiation.

은행잎 추출물 도포 모발의 물성(物性)에 관한 융합적 연구 (A convergence study on the properties of hair coated with Ginkgo biloba extract)

  • 박장순
    • 한국융합학회논문지
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    • 제11권8호
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    • pp.223-228
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    • 2020
  • 아름다운 헤어스타일을 위하여 건강한 모발을 꾸준히 관리해야 할 필요성이 강하게 대두(擡頭)되고 있으며, 시대적 요구에 따라 인체에 무해(無害)한 천연 항산화 물질을 활용한 모발 화장품 개발이 필요한 시점이다. 이에 매우 탁월한 생리활성 성분이 이미 입증된 은행잎(Ginkgo biloba L.) 추출물을 도포 한 모발에 대한 최대 하중, 최대 인장강도, 최대 신장률, 파단 하중, 파단강도, 파단 신장률, 구간에 따른 Max. modulus와 Tangential modulus 값 등 다양한 융합적인 물성(物性)실험을 하였다. 연구 결과 은행잎 추출물을 도포 한 모발은 대조군에 비하여 인장강도를 포함한 고유 물성값이 전반적으로 증가하였다. 본 연구를 통해 은행잎이 기존 출시된 건강보조식품이나 의약품뿐만 아니라 퍼머넌트 웨이브 제재와 같은 모발 화장품의 유용한 재료로서의 가능성에 대해 연구를 하고자 하며, 다양한 모발 화장품의 후속개발을 위한 유용한 연구자료로 제공되기를 기대한다.

무지 외반증에서 Akin 절골술 내측 횡 봉합사 고정술의 결과 (The Results of Medial Horizontal Suture Fixation of Akin Osteotomy in Hallux Valgus)

  • 윤영필;김정훈
    • 대한족부족관절학회지
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    • 제21권1호
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    • pp.1-6
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    • 2017
  • Purpose: The purpose of this study was to analyze the clinical results of medial horizontal suture fixation of Akin osteotomy in hallux valgus and present its advantages. Materials and Methods: This study was based on 48 cases of 35 patients with Akin osteotomy, who underwent surgery of hallux valgus between December 2014 and July 2015, and with at least 12 months of follow-up. The mean age of patients was 46.9 years (range, 16~71 years). The mean follow-up duration was 15.9 months (range, 12~18 months). Clinical evaluations included pain visual analogue scale (VAS) score, American Orthopaedic Foot and Ankle Society (AOFAS hallux metatarsophalangeal interphalangeal scale) score, and satisfaction score. Weightbearing anteroposterior radiographs were taken to measure the distal articular set angle (DASA) of the hallux. Radiographic bone union at 6 months follow-up was regarded as a success, while a loss of reduction and nonunion was regarded as a failure. Results: The mean pre- and postoperative pain VAS scores were 4.27 and 1.67, respectively (p<0.05). The mean AOFAS score improved from 59.7 to 80.5 (p<0.05). The DASA was improved from 8.15 to -2.57 (p<0.05). There was no case of skin irritation, cortical breakage, inflammation from the knot, and infection. All patients showed union without fixation failure. Conclusion: The clinical and radiological evaluations in this study demonstrate reliable results without complication. The medial horizontal suture fixation of the Akin osteotomy was effective, and the advantage of this procedure was unnecessity of the material removal, preservation of the joint, and no skin irritation.

청소년 비행정도와 의복태도 및 의복규제 태도와의 관계 (A Study on the Relation between Delinquency and Clothing Attitude, clothing regulation attitude for Adolescent)

  • 이명희;홍선옥
    • 한국의상디자인학회지
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    • 제3권1호
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    • pp.129-152
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    • 2001
  • The purpose of this study was to classified as the degree of the delinquency and to make clear the differences of adolescents' clothing attitude, clothing regulation attitude according to their delinquency and demographic variables. The results are as follows: First, Delinquency was classified as revolt, breakage and violence, status and property; according to the degree of the delinquency, subjects were categorized as delinquent, middle and exemplary groups. Second, the clothing conformity and clothing importance were higher in delinquent and middle than exemplary group; individuality, fashion and refusal against clothing regulation were most regarded by delinquent group, and followed by and middle and exemplary groups, meanwhile, the reverse was the case for modesty. Third, schoolgirls were more regarded the conformity, individuality, fashion and clothing importance and higher the refusal against clothing regulation than schoolboys; there was no significant difference between both sexes in modesty, and schoolgirls in delinquent group were more fiercely refused the clothing regulation than schoolboys in same group. The better a student did at school, the higher the modesty was and the lower the fashion and refusal against clothing regulation were. The higher a student belonged to a social status, the more he/she regarded the individuality importantly. While exemplary student who belonged to a high social status tended to pursue the individuality regardless his/her degree of delinquency, as for the student who belonged to middle or below social status, the higher the degree of delinquency was, the more he/she regarded the individuality. Besides, delinquent students who belonged to middle or below social status were more sensitive in fashion than those to higher social status.

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다양한 실리콘 웨이퍼 제조를 위한 와이어 전기 방전가공 (Wire Electric Discharge Machining Process of Various Crystalline Silicon Wafers)

  • 문희찬;최선호;박성희;장보윤;김준수;한문희
    • 한국전기전자재료학회논문지
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    • 제30권5호
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    • pp.301-306
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    • 2017
  • Wire electrical discharge machining (WEDM) process was evaluated to slice Silicon (Si) for various applications. Specifically, various Si workpieces with various resistances, such as single and multi crystalline Si bricks and wafers were used. As conventional slicing processes, such as slurry-on or diamond-on wire slicing, are based on mechanical abrasions between Si and abrasive, there is a limitation to decrease the wafer thickness as well as kerf-loss. Especially, when the wafer thickness is less than $150{\mu}m$, wafer breakage increases dramatically during the slicing process. Single crystalline P-type Si bricks and wafers were successively sliced with considerable slicing speed regardless of its growth direction. Also, typical defects, such as microcracks, craters, microholes, and debris, were introduced when Si was sliced by electrical discharge. Also, it was found that defect type is also dependent on resistance of Si. Consequently, this study confirmed the feasibility of slicing single crystalline Si by WEDM.

축추-환추간 경관절 나사못 고정술 치료의 결과 및 합병증 (The Results and Complications of the C1-C2 Transarticular Screw Fixation Methods)

  • 최준웅;윤승환;박형천;박현선;김은영;하윤
    • Journal of Korean Neurosurgical Society
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    • 제37권3호
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    • pp.201-206
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    • 2005
  • Objective: To evaluate the accuracy and safety of C1-C2 transarticular screw insertion, we retrospectively review surgical records and postoperative radiological findings. Methods: From January 2001 to October 2003, the C1-C2 transarticular screw fixation and posterior wiring with iliac bone grafts was performed in 16 patients. 6 patients had rheumatoid arthritis which caused cervical instability, 3 patients had os odontoideum, 3 patients had type 2 odontoid process fracture, 3 patients had traumatic transverse ligament injury and 1 patients who had been managed with C1-C2 wire fixation had psoriatic arthritis. Results: Osseous fusion was documented in 15 patients(93.8%). Only one patient was recorded screw loosening because of postoperative infection. One patient had only one screw placed because of abnormal anatomical structure, one patients was breakage of a Kirschner wire, and one screw was medial location to lateral mass of C1, but clinical results was excellent and radiological instability was not noted. Conclusion: The author's experience demonstrates that C1-C2 transarticular screw fixation with wired bone graft is a safe procedure with higher fusion rate but precaution is needed to avoid the neural damage, vertebral artery injury, and hardware failure.

진공챔버 내 프리트 이용 진공유리 봉지공정 최적화에 관한 연구 (A Study on Optimization of Vacuum Glazing Encapsulating Process using Frit inside a Vacuum Chamber)

  • 박상준;이영림
    • 한국산학기술학회논문지
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    • 제14권2호
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    • pp.567-572
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    • 2013
  • 냉난방을 사용하는 가정에서는 대부분 창문을 통해 열손실이 이루어지고 있는데 이를 방지하기 위해 Low-E 유리, 복층유리 또는 진공유리가 사용되고 있다. 본 논문에서는 진공유리 제작공정의 최종공정인 봉지공정에 대한 연구가 수행되었는데 기존 상압 접합이 아닌 진공챔버 내 접합이 고려되었다. 봉지과정의 효율성을 위해 진공챔버 내에서 히터온도에 따른 프리트 용융온도 및 접합시간을 최적화하였고 열응력으로 인한 유리 파손을 방지하기 위해 유리 예열온도를 최적화하였다. 이러한 결과를 바탕으로 성공적으로 진공유리를 제작하였고 측정된 열관류율은 약 $5.7W/m^2K$로 진공유리 내부압력은 약 $10^{-2}$ torr로 판명되었다.

전술 모바일 애드혹 네트워크에서 무인기를 이용하는 이동 예측 기반의 데이터 링크 연결 유지 알고리즘 (Mobility Prediction Based Autonomous Data Link Connectivity Maintenance Using Unmanned Vehicles in a Tactical Mobile Ad-Hoc Network)

  • 르반둑;윤석훈
    • 한국통신학회논문지
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    • 제38B권1호
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    • pp.34-45
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    • 2013
  • 자가구성 능력을 가진 전술모바일애드혹 네트워크는 기간망을 사용할 수 없는 전술환경에서 단위전술부대와 중앙지휘소와의 통신연결을 제공하기 위해 사용된다. 하지만, 작전 전술부대가 임무수행을 위해 중앙지휘소로부터 장거리 위치로 이동하거나 지형적 장애물이 있는 경우에는 통신단말간 데이터링크가 단절되어 전술부대로부터 지휘소까지의 데이터 경로가 유효하지 않을 수 있다. 이러한 문제를 해결하기 위하여 본 논문에서는 ADLCoM(Autonomous Data Link Connectivity Maintenance) 구조를 제안한다. ALDCoM하에서 각 전술그룹단위는 하나이상의 GW 노드 (게이트웨이)를 갖으며 GW 노드들은 전술부대 및 지휘소 간의 데이터 링크상태를 지속적으로 확인한다. 만약 데이터링크가 단절될 가능성이 높다면 하나이상의 육상 또는 공중 무인기를 데이터링크를 위한 릴레이로서 동작하도록 요청하여 전술 부대 및 지휘소간, 또는 전술 부대간의 데이터링크의 연결을 지속적으로 유효하게 유지 시킨다. 전술환경을 모의한 시뮬레이션을 통하여 ADLCoM구조가 전술모바일애드혹망의 성능을 현저히 높일 수 있음을 보인다.

3D 프린트를 통해 제작된 손목 보조기의 유한요소해석 (Finite Element Analysis of Wrist Orthosis with 3D Printing)

  • 최현우;강인영;노건우;서안나;이종민
    • 한국방사선학회논문지
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    • 제13권7호
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    • pp.947-953
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    • 2019
  • 임상에서 사용하는 진단 검사 장치인 전산화 단층촬영기와 자동화된 설계 소프트웨어(MediACE 3D Prog ram), 3D 프린터로 손목 보조기를 제작하고자 하였다. 전산화단층촬영기로 상지의 Dicom 파일을 획득한 후 MediACE 3D Program을 통해 손목 보조기를 디자인하여 "STL(stereolithography)"파일을 만들었고, 디자인된 손목 보조기는 3D 프린터를 이용하여 인쇄하였다. 3D 프린팅 기술로 제작된 손목보조기의 효용성 검증을 위해 뼈와 피부에 가해지는 압력 및 보조기의 스트레스 분포를 유한요소해석으로 나타내었다. 손목 보조기를 제작할 때 유한요소해석의 결과를 가지고 뼈와 피부가 압력에 의한 손상과 보조기의 파손이 자주 일어나는 부위를 보강하여 손목 보조기를 제작할 수 있을 것이라고 기대된다.

서울시내 주거지역 미세먼지의 유전독성 영향 (Genotoxic Effect of Air-borne Particulate Matter in Residential Area of Seoul City)

  • 오승민;성혜경;김은실;김종극;유병택;정규혁
    • Environmental Analysis Health and Toxicology
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    • 제20권4호통권51호
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    • pp.365-374
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    • 2005
  • Ambient air particulate matters are classified into two distinct modes in sire distribution, namely the coarse and fine particles. Correlation between high particulate concentration and adverse effect on human populations has long been recognized. However, the toxicology of these adverse efforts has not been clarified. We investigated the genotoxic effect of PM 2.5 collected from urban area in Seoul by comet assay (A549 cells), CBMN assay (CHO-K1 cells) and EROD-microbioassay (H4IIE cells). Results from in vitro micronucleus assay and comet assay showed that PM 2.5 samples collected from traffic area, residential area and indoor air induced chromosomal damage and DNA breakage in a non-cytotoxic dose. The complex mixture effect of these PM 2.5 extracts was quantified by EROD-microbioassay in terms of its bio-TEQ (biologiral -TCDD equivalent concentration) which was 70.87$\pm$28.07, 93.55$\pm$21.80 and 14.31 $\pm$ 1.10 ng/g-PM 2.5 in traffic area, residental area and indoor air samples, respectively. Conclusively, we suggested that PM 2.5 collected from traffic area and residential area contains CYPIA inducer and genotoxic materials.