• Title, Summary, Keyword: 가역성

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Effects of nicotine on the attachment and proliferation of periodontal ligament cells, and reversibility of nicotine-induced cytotoxicity (니코틴이 치주인대세포의 부착과 증식에 미치는 영향 및 니코틴에 의해 야기된 세포독성의 가역성에 대한 연구)

  • Kim, Hye-Kyung;Park, Jin-Woo;Choi, Byung-Ju;Suh, Jo-Young
    • Journal of Periodontal and Implant Science
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    • v.35 no.2
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    • pp.475-490
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    • 2005
  • 본 실험은 흡연이 치주인대세포의 기능에 미치는 영향을 알아보기 위해 담배 부산물 중 하나인 니코틴이 지주인대세포의 부착과 성장 및 세포의 가역성에 미치는 영향을 관찰하였다. 니코틴이 치주인대세포의 부착에 미치는 영향을 관찰하기 위하여 치주인대세포에 니코틴을 투여한 후 1, 3, 6, 12, 24시간째 trypan blue 염색 후 부착된 세포수의 측정과 H&E stain후 형태학적 관찰을 하였고 니코틴이 치주인대세포의 성장에 미치는 영향을 관찰하기 위하여 치주인대세포에 니코틴을 투여한 후 1, 4, 7, 11, 14일째 trypan blue 염색 후 증식된 세포수의 측정과 H&E stain후 형태학적 관찰을 하였다. 또 니코틴의 세포독성효과의 가역성 평가를 위하여 니코틴을 투여하고 1, 4, 7, 11일째 니코틴이 없는 새로운 배지로 갈아주어 2일 더 배양한 후 trypan blue로 염색하여 세포수를 측정, 비교하였고 H&E 염색 후 형태학적 관찰을 하였다. 실험결과 니코틴 농도가 증가함에 따라 치주인대세포의 부착율은 감소되었고 24시간 배양 후 2mg/ml, 0.5mg/ml, 0.1mg/ml니코틴 투여군에서 통계학적으로 유의성 있는 부착억제가 관찰되었고(P<0.01) 형태학적 관찰결과 2mg/ml, 0.5mg/ml 니코틴 투여군에서는 대조해서 관찰되는 세포질의 확장이 관찰되지 않았다. 니코틴이 치주인대세포의 증식에 미치는 효과를 살펴본 결과 2mg/ml, 0.5mg/ml, 0.1mg/ml 니코틴 투여군에서 증식억제가 관찰되었고(P<0.01) 0.005mg/ml이하의 니코틴 투여군에서는 아무런 변화도 관찰되지 않았다. 14일 배양 후 형태학적 관찰결과 0.1mg/ml 니코틴 투여군에서 세포질내 공포를 관찰할 수 있었고 2mg/ml, 0.5mg/ml 니코틴 투여군에서는 세포의 괴사가 나타났다. 니코틴의 세포독성효과의 가역성평가결과 2mg/ml이상의 니코틴은 세포에 비가역적인 손상을 일으키며 0.5mg/ml, 0.1mg/ml 니코틴에 의한 세포독성은 초기에는 가역적이나 장기간 세포에 노출시키면 비가역적인 손상을 야기하는 것으로 나타났다.(P<0.05) 본 실험결과 담배의 구성성분 중 니코틴은 농도 의존적으로 치주인대세포의 부착과 증식에 영향을 주었고 니코틴의 치주인대세포에 대한 독성효과는 농도가 증가할수록, 시간이 지닐수록 비가역적으로 나타났다. 따라서 흡연은 치주조직재생에 영향을 미칠 것으로 생각되며 흡연의 기간과 정도가 치주질환의 심도 및 치주치료 후 불량한 치유반응과 관계가 있을 것으로 사료된다.

Interval-based Audio Integrity Authentication Algorithm using Reversible Watermarking (가역 워터마킹을 이용한 구간 단위 오디오 무결성 인증 알고리즘)

  • Yeo, Dong-Gyu;Lee, Hae-Yeoun
    • The KIPS Transactions:PartB
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    • v.19B no.1
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    • pp.9-18
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    • 2012
  • Many audio watermarking researches which have been adapted to authenticate contents can not recover the original media after watermark removal. Therefore, reversible watermarking can be regarded as an effective method to ensure the integrity of audio data in the applications requiring high-confidential audio contents. Reversible watermarking inserts watermark into digital media in such a way that perceptual transparency is preserved, which enables the restoration of the original media from the watermarked one without any loss of media quality. This paper presents a new interval-based audio integrity authentication algorithm which can detect malicious tampering. To provide complete reversibility, we used differential histogram-based reversible watermarking. To authenticate audio in parts, not the entire audio at once, the proposed algorithm processes audio by dividing into intervals and the confirmation of the authentication is carried out in each interval. Through experiments using multiple kinds of test data, we prove that the presented algorithm provides over 99% authenticating rate, complete reversibility, and higher perceptual quality, while maintaining the induced-distortion low.

A Study in the Temporality in Digital Gameplay (디지털 게임 플레이의 시간성 연구)

  • Lee, Dong-Eun
    • Journal of Korea Game Society
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    • v.13 no.2
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    • pp.5-16
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    • 2013
  • The purpose of this study is how to occur the temporality in Digital Gameplay. There is two types of time in Gameplay. One is Irreversibility time that goes passed through a game world like a chronology order. Another is Reversibility time that returns and renews the time. The time's duality is caused by player's intervene and experience. And the polychronic temporality in gameplay makes the rhythm as replay and eternal cyclic time.

Reversible Watermarking based on Differential Histogram for Medical Imagery (의료 영상에 대한 차이값 히스토그램 기반 가역 워터마킹 연구)

  • Oh, Gi-Tae;Jang, Han-Byul;Do, Um-Ji;Lee, Hae-Yeoun
    • Proceedings of the Korea Information Processing Society Conference
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    • pp.876-879
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    • 2014
  • 디지털 워터마킹을 위하여 강인성, 연성 등 특징을 갖는 다양한 기술들의 개발이 완료된 상태이다. 그러나 원본 콘텐츠의 품질을 중요시하는 분야에서 가역 워터마킹 기술에 대한 필요성이 증가하고 있다. 현재 다양한 분야에서 가역 워터마킹의 기술에 대한 다양한 연구 개발이 진행 중이며, 본 논문에서는 아직 많은 연구들이 이루어지지 않은 의료영상에 대한 가역 워터마킹에 대해 연구한다. 본 연구팀이 보유하고 있는 추정 오차 확장 및 오류 예측 보정을 통한 다양한 고용량 가역 워터마킹 기술들을 의료영상에 변형하여 적용함으로서 삽입용량과 영상품질을 측정하였다. 이에 따르면 차이값 추정 오차가 적은 보간 기술을 사용한 방법이 삽입용량 대비 PSNR이 좋은 성능을 보여주었다.

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Least Square Prediction Error Expansion Based Reversible Watermarking for DNA Sequence (최소자승 예측오차 확장 기반 가역성 DNA 워터마킹)

  • Lee, Suk-Hwan;Kwon, Seong-Geun;Kwon, Ki-Ryong
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.11
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    • pp.66-78
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    • 2015
  • With the development of bio computing technology, DNA watermarking to do as a medium of DNA information has been researched in the latest time. However, DNA information is very important in biologic function unlikely multimedia data. Therefore, the reversible DNA watermarking is required for the host DNA information to be perfectively recovered. This paper presents a reversible DNA watermarking using least square based prediction error expansion for noncodng DNA sequence. Our method has three features. The first thing is to encode the character string (A,T,C,G) of nucleotide bases in noncoding region to integer code values by grouping n nucleotide bases. The second thing is to expand the prediction error based on least square (LS) as much as the expandable bits. The last thing is to prevent the false start codon using the comparison searching of adjacent watermarked code values. Experimental results verified that our method has more high embedding capacity than conventional methods and mean prediction method and also makes the prevention of false start codon and the preservation of amino acids.

High-Capacity Reversible Watermarking through Predicted Error Expansion and Error Estimation Compensation (추정 오차 확장 및 오류 예측 보정을 통한 고용량 가역 워터마킹)

  • Lee, Hae-Yeoun;Kim, Kyung-Su
    • The KIPS Transactions:PartB
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    • v.17B no.4
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    • pp.275-286
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    • 2010
  • Reversible watermarking which can preserve the original quality of the digital contents and protect the copyright has been studied actively. Especially, in medical, military, and art fields, the need for reversible watermarking is increasing. This paper proposes a high-capacity reversible watermarking through predicted error expansion and error estimation compensation. Watermark is embedded by expanding the difference histogram between the original value and the predicted value. Differently from previous methods calculating the difference between adjacent pixels, the presented method calculates the difference between the original value and the predicted value, and that increases the number of the histogram value, where the watermark is embedded. As a result, the high capacity is achieved. The inserted watermark is extracted by restoring the histogram between the original value and the predicted value. To prove the performance, the presented algorithm is compared with other previous methods on various test images. The result supports that the presented algorithm has a perfect reversibility, a high image quality, and a high capacity.

A Case of Posterior Reversible Encephalopathy Syndrome during Cyclosporine Therapy in a Child with Steroid Resistant Nephrotic Syndrome (스테로이드 저항성 신증후군 환아에서 사이클로스포린 투여 중 발생한 후두엽 가역성 뇌병증 증후군 1례)

  • Jeong, Min-Hee;Lee, Joo-Hoon;Yum, Mi-Sun;Ko, Tae-Sung;Park, Young-Seo
    • Childhood Kidney Diseases
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    • v.11 no.1
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    • pp.92-99
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    • 2007
  • The posterior reversible encephalopathy syndrome(PRES) is characterized clinically by a combination of acute or subacute confusion, lethargy, visual disturbance, and seizures. PRES has been described in various clinical settings, including severe hypertension, chemotherapy, eclampsia, and seizure. We report a case of a 7-year-old girl who had taken cyclosporine for steroid resistant nephrotic syndrome. Twenty one days after the cyclosporine therapy, she was admitted due to generalized tonic clonic seizure and headache. Her blood pressure was 170/90 mmHg. Magnetic resonance(MR) imaging showed necrotic/cystic lesions involving the bilateral parieto-occipital region. After discontinuation of cyclosporine, and control of blood pressure, she had no more seizure and headache. The follow-up MR examination which was performed 6 months later showed the decreased extent of the lesion.

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Difference of Time Course of Functional Recovery after Revascularization According to Preoperative Reversibility of Perfusion Impairment in Ischemic Myocardial Dysfunction (허혈성 심근 기능장애에서 술전 관류결손의 가역성에 따른 재관류 시술 이후 심근 기능회복 양상의 시간적 차이)

  • Paeng, Jin-Chul;Lee, Dong-Soo;Kim, Ki-Bong;Kim, Yu-Kyeong;Yeo, Jeong-Seok;Chung, June-Key;Lee, Myung-Chul
    • The Korean Journal of Nuclear Medicine
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    • v.35 no.6
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    • pp.364-370
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    • 2001
  • Purpose: In the revascuarization of ischemic dysfunctional myocardium, stunned myocardium was reported to recover function earlier than hibernating myocardium. It was also suggested that stunning and hibernation could be discriminated by reversibility of perfusion impairment on myocardial SPECT. In this study, we investigated the time course of functional recover after CABG according to reversibility of perfusion impairment. Materials and Methods: In 92 patients with coronary artery disease, Tl-201 rest/dipyridamole stress Tc-99m-MIBI gated SPECT was performed before, 3 months after, and 17 months after CABG. Using a 20-segment model, segmental perfusion and systolic thickening were automatically quantified. Perfusion-impaired segments with abnormal thickening were classified by reversibility into reversible (REV) and irreversible (IRREV) groups. The proportions of function-recovered segments were compared between groups and also between 3 months and 17 months in each group. Results: A total of 129 segments were Included In the analysis, and 76 were REV and 53 were IRREV. At 3 months after CABG, 61 segments (80%) in REV group showed functional recovery while 28 segments (53%) in IRREV group did (p<0.001). However, at 17 months after CABG, 60 segments (79%) in REV group and 37 segments (70%) un IRREV group showed functional recovery (p=n.s.). When comparing 3 months and 17 months in each group, REV group showed no difference, while IRREV group showed significant further improvement (p<0.05). Conclusion: In viable myocardium with ischemic myocardial dysfunction, the segments with reversible perfusion impairment recover function earlier after revascularization than irreversible segments.

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Study on the Development and Properties of Ceramics Restoration Purpose Urethane resin with Excellent Reversibility (가역성이 우수한 도자기 복원용 Urethane resin의 개발 및 물성에 대한 연구)

  • Oh, Seung Jun;Park, Gi Jung;Wi, Koang Chul
    • Journal of Conservation Science
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    • v.31 no.1
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    • pp.37-46
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    • 2015
  • In the case of adhesives & restoration agents currently being used for the preservation treatment of ceramics and earthenware, epoxy type, cellulose type and cellulose type are mainly being used. However, they are showing various problems such as re-detachment from severe contraction, color change from yellowing, work inconvenience of staining on tools and hand during usage and irreversibility. For the purpose of solving the issues of yellowing and irreversibility of epoxy resin being used to restore ceramics, urethane synthetic resin with low yellowing excellent reversibility has been developed in this study. The adhesive strength of urethane resin that has been developed has excellent properties with 2.07MPa for undiluted solution, which is 1.5 times higher than that of existing material EPO-$TEK301^{(R)}$ 1.21MPa. The result of workability measurement showed that the wear rate of urethane resin (in Talc 50wt%) was 1.09%, which was somewhat higher than that of existing material Quick $Wood^{(R)}$ (1.02%). In addition, its wear rate is two times higher than that of $EPO-TEK301^{(R)}$ (0.41%) and $L30^{(R)}$ (0.39%), thereby showing an advantage in its forming process compared to existing materials. As for the advantage of urethane resin of reversibility experiment, 12 hours after acetone, ethyl alcohol deposition, urethane resin and filler talc were dissolved 100% while showing powdering phenomenon. Compared to 0% reversibility of existing epoxy resin, it has much superior reversibility. The result of UV rays experiment to evaluate its durability showed that ${\Delta}E^*ab$ color change value based on undiluted solution of urethane resin was 2.76 before & after UV rays exposure, which was a decrease by about 7-20 times compared to that of existing resin, thereby minimizing the issue of heterogeneity.