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      • RAW264.7 세포에서 interferon-r 및 LPS에 의해 유도되는 NO생성에 미치는 TALT-35의 영향

        박종일,박경석,김종석,박지훈,윤은진,송경섭,서강식,김훈,윤완희,박승길,임규,황병두 충남대학교 생물공학연구소 2006 생물공학연구지 Vol.12 No.-

        TALP-35 purified from human term placenta is known to increase microtubule polymerization and stabilize the polymerized microtubule. To examine the effect of TALP-35 on immune system this study was performed. MTT assay was performed to investigate the effect of TALP-35 on the proliferation of RAW264.7 cells. TALP-35 dose dependently suppress the proliferation of RAW264.7 cells at high concentration (above 1 μM) in unstimulated cells, in case of 10 μM TALP-35 treated cells the suppression was 25% but in stimulated cells it was only 15%. Cosedimentation assay was carried out to investigate whether TALP-35 can bind to tubulin of RAW264.7, monocyte/macrophage lineage of mouse, and polymerize it. TALP-35 polymerize the tubulin of RAW264.7 cells and sedimented in dose-dependent manner. To investigate the effect of TALP-35 on the expression of iNOS protein western blotting was performed. The expression level of iNOS was decreased dose dependently in high concentration of TALP-35 treatment. To examine the activity of iNOS, secreted NO was determined by method based on Griess reaction. Interferon-γ and LPS-stimulated production of NO from RAW264.7 cells was decreased dose dependently above 0.1 μM concentration of TALP-35 and 50% is decreased at 10μM of it. This study shows TALP-35 can control cytokine induced-iNOS expression therefore it might control inflammatory diseases.

      • SCIESCOPUSKCI등재
      • 파라메터 추정과 슬라이딩 모드를 이용한 상태관측기 구성에 관한 연구

        박승규,박두환,김민찬 國立 昌原大學校 產業技術硏究院 2004 産技硏論文集 Vol.18 No.-

        The observer which is based on sliding mode is robust to uncertainties. It has the error dynamic independent on disturbances or noises. But its dynamics are very coservative because of its dependence of output error. So, in this paper, an observer with a novel sliding mode is proposed. The sliding mode of this observer is designed by defining a extended error state whose dynamic is determined from the output error. In addition to this advantage, the RLS algorithm is made more useful by proposing the data obtaining method from the existing experimental data. The performace of the sliding mode observer can be improved using the parameters from the RLS algorithm.

      • KCI등재

        허혈 및 재관류후 흰쥐 앞정강근과 가자미근에서 나타나는 미세구조와 SOD 활성의 변화

        백두진,안동춘,황규성,김혜주,박철홍,정호삼,조근열 대한체질인류학회 1999 해부·생물인류학 (Anat Biol Anthropol) Vol.12 No.2

        에너지 획득방법, 당원의 분포, 모세혈관의 분포 및 미세구조의 차이가 나는 백색근육섬유와 적색근육섬유에서 허혈시간에 따라 나타나는 미세구조의 변화와 SOD의 활성변동을 비교 관찰하여 다음과 같은 결과를 얻었다. 1. 앞정강근에서는 2시간 허혈시 사립체에서 바탕질의 전자밀도가 감소하고 사립체능선이 팽대하였고, 재관류 24시간 경과시에는 근육원섬유사이의 거리가 멀어지고 근육세포질세망의 수조와 종말수조가 팽대하였으며 재관류 72시간 경과시에는 정상대조군과 유사한 소견이 나타났다. 2. 가자미근에서 2시간 허혈시 사립체에서는 사렵체바탕질의 전자밀도가 감소하였으며, 재관류 24 시간 경과시는 근육세포질세망의 수조가 팽대하였고, 재관류 72시간 경과시에는 정상대조군과 유사하였다. 3. 4시간 및 6시간 허혈시 미세구조의 변화는 허혈시간과 재관류 시간경과에 따라 심해져 앞정강근에서는 사립체에서 바탕질의 전자밀도가 감소하고 사렵체능선은 불분명하고 소용돌이소체가 나타났으며 근육원섬유 용해와 곤육원섬유괴사가 관찰되었다. 가자미근에서는 근육원섬유에서 근육미세섬유의 배열과 끝가로막이 불규칙해지고 근육세포질세망의 수조가 팽대하였으며 근육원섬유용해가 나타났다. 4. 앞정강근에서 Cu, Zn-및 Mn-SOD 활성은 미약한 흑은 약한 양성반응을 나타내었고, 가자미근에서는 Cu, Zn-SOD는 미약한 양성반응을, Mn-SOD 는 미약한 혹은 약한 양성반응을 나타내었다. 허혈후 Cu, Zn- 및 Mn-SOD 의 활성은 허혈시간이 길수록 더욱 증가하였다. 5. Cu, Zn- 및 Mn-SOD 활성은 2시간 허혈 및 재관류 24 시간 경과시 약간 증가하였으며 72시간 경과시에는 앞정강근과 가자미근에서 정상대조군과 유사하게 나타났다. 6. 4시간 및 6시간 허혈 및 재관류후 두 근육에서 Cu, Zn- 및 Mn-SOD활성은 증가하였다. 두 근육에서 Mn-SOD의 활성변동은 유사하였으나 Cu, Zn- Mn-SOD의 활성증가는 앞정강근보다 가자미근에서 크게 나타났다. 이상의 결과를 종합하면 허혈 및 재관류 손상은 허혈시간과 재관류시간 경과에 따라 심하게 나타났고 가자미근보다 앞정강근에서 심하게 나타났으며, 손상의 차이는 두 근육에서 나타나는 SOD활성변동과 깊은 연관이 있는 것으로 생각된다. Skeletal muscles are known to have tolerance to ischemia, but a prolonged ischemia can cause damage to muscular tissues. The ischemia-reperfusion injury results from the oxygen free radicals released by leucocytes and formed by the reaction of hypoxanthine and xanthine oxidase. Superoxide dismutase (SOD), one of major antioxidant enzymes occurring in the various tissues of the body metabolizes or scarvanges the oxygen free radicals. Although many studies reported difference in tolerance to ischemia and reperfusion between white and red muscles, some other investigators failed in finding such difference. The present study was performed to examine effects of graded periods of ischemia and reperfusion on the cellular ultrastructure and activity of SOD in white and red muscles. The Sprague-Dawley rats (200~250 g) were used as experimental animals. Under pentobarbita] (50 mg/kg IP) anesthesia, incision was made on lower abdomen and left common iliac artery was occluded by means of a vascular clamp for 2, 4 and 6 hour (hrs). Thereafter, the superficial portion of mid-belly of anterior tibial muscle and soleus muscles were excised at 0, 24 and 72 hrs after onset of reperfusion. The specimens were sectioned into slices, 2 mm in length, 1 mm in width and thickness. Some specimens were prepared for electron microscopic observation and others for determination of SOD activity by using antihuman CU, Zn- and Mn-SOD antibodies. The results obtained were as follows. 1. In anterior tibial muscle, areas with loose electron-density and dilated cristae were observed in the mitochondria immediately after 2 hrs of ischemia, while widened intermyofibrillar spaces and dilated cisternae of sarcoplasmic reticulum were seen after 2 hrs and 24 hrs reperfusion. When subjected to 2 hrs ischemia and 72 hrs reperfusion, no significant change was found in the cellular ultrastructure. 2. In soleus muscle, electron density was loose in the matrix of mitochondria immediately after 2 hrs of ischemia, while cisternae of sarcoplasmic reticulum were dilalated after 2 hrs of ischemia and 24 hrs reperfusion. Following 2 hrs of ischemia and 72 hrs repeifusion, the electron microscopic findings were similar to those of normal rats. 3. The changes in cellular ultrastructure were more prominent in both the 4 hrs and 6 hrs ischemia groups, in which degree of ultrastructural changes were proportional to duration of reperfusion. 4. In anterior tibial muscle, trace or weak immunoreactivities of Cu, Zn- and Mn-SOD were seen, whereas trace immunoreactivity of Cu, Zn-SOD and trace or weak immunoreactivity of Mn-SOD were observed in soleus muscle. 5. The immunoreactivities of CU, Zn- and Mn-SOD were not altered in 2 hrs ischemic and 72 hrs reperfused group, while they were increased slightly in 2 hrs ischemic and 24 hrs reperfused group. 6. In both muscles, the activity of SOD increased following 4 hrs or 6 hrs ischemia and 24 hrs or 72 hrs reperfusion. The changes in immunoreactivity of Mn-SOD were not different between two muscles, whereas immunoreactivity of Cu, Zn-SOD were higher in anterior tibial muscle. Consequently, it is suggested that significant ischemia reperfusion injuries are produced after 4 ~ 6 hrs ishemia followed by 24 hrs or 72 hrs reperfusion, that anterior tibial muscle is more susceptible to ischemic reperfusion injury and that the ischemic-reperfusion injury is closely related with activity of SOD.

      • SCIESCOPUSKCI등재
      • 水素化된 非晶質 게르마늄의 特性調査(Ⅰ)

        梁承勳,李原鎭,朴奉斗 慶北大學校 1985 論文集 Vol.39 No.-

        Reactive thermal evaporation(RTE) was developed as a new method to deposit hydrogenated amorphous germanium films. RTE was carried out by the evaporation of high purity polycrystalline germanium in an atmosphere of hydrogen plasma produced by high voltage AC discharge of molecular hydrogen. Electrical conductivity and its annealing behavior, electron probe micro-analyzer and scanning electron microscopy were used to characterize the samples. Optimal conditions of sample preparation (from electronic point of view) were determined to be substrate temperature of 200℃ and hydrogen pressure of 1 Torr. Crucible type was proved to have an influence on the sample properties. The sample prepared at the optimum conditions shows the activated type conduction above room temperature.

      • Nonlinear 구성방정식을 이용한 트레드 고무블록의 접지압 해석

        김두만,김용엽,박인정,유현승 한국 항공대학교 항공산업기술연구소 2000 航空宇宙産業技術硏究所 硏究誌 Vol.10 No.-

        자동차용 트레드블록의 형상디자인을 위한 설계인자를 도출하고자, 해석적 방법과 실험을 통하여, 트레드블록 접지면에서의 접지압을 해석하였다. 본 연구에서는 더욱 복잡한 elastomer의 거동을 해석하고자, 비교적 간단하면서 large strain에서도 잘 맞는 것으로 알려진 Mooney-Rivlin Model을 제시하였으며, 접지압을 계산하여, Nonlinear elastic 거동 해석에 쓰이는 다른 몇몇 이론들과 비교, 검토하였다. 또한, 접지압 분포의 경향을 실험과 함께 분석함으로서, 실제 거동에 가장 적절한 Model을 제시하였다. To analyze the stress distribution on the contact surface of Tread block, and to provide the factor of design for the shape of tread block for automobile, the tread block has been analyzed the stress distribution on the surface of contact by analytical method and experiment. In this study, to analyse the contact stress on the elastomer, Mooney-Rivlin model has been suggested which is comparatively simple and well fit to the behavior of rubber-like materials. Also, Hooke's model and Neo-Hookean model were compared and investigated. The experiment was conducted to verify the results and we suggested the most efficient model to analyse the contact stresses of rubber block.

      • PTPase의 작용에 menadione이 미치는 활성 기작

        함승욱,박희중,임두현 中央大學校 基礎科學硏究所 1995 基礎科學硏究所 論文集 Vol.9 No.-

        Vitamin K₃(menadione) has been shown to exhibit a broad range of antitumor activity in human cells as well as a phosphatase cofactor. It also imposed lower level of toxicity than other cancer chemotherapeutic drugs of quinone structure. Juan and Wu have recently demonstrated that the action of menadione is dose-dependent and cell cycle-specific. In this study, we have examined the effect of menadione in the action of cdc25 PTPase which is important of the control of cell cycle progression by the signal transduction pathway. Our mechanistic analysis with the model reaction has led to a new interpretation of the role of menadione. We also investigated that thiolate addition of cdc25 PTPase to menadione leads to directly to irreversible inhibition by covalent modification.

      • 반응성 가열 증착법에 의한 수소화된 비정질 게르마늄 제작

        梁承勳,李原鎭,朴奉斗 慶北大學校 1984 論文集 Vol.37 No.-

        The addition of hydrogen during the evaporation of germanium has been shown to improve the electrical properties of the resulting a-Ge film considerably by saturation of dangling bonds, if the dissociation of molecular hydrogen by high voltage AC discharge takes place. Evaporation onto a substrate at 200℃ in the mood of hydrogen plasma has been shown to yield a film which shows a high resistance and an activated type conduction(with an activation energy of 0.38eV) above room temperature.

      • 내압 및 수직하중 작용시 Radial Tire Sidewall부 변형의 시간에 따른 변화 연구

        성경진,박인정,유현승,김두만 한국 항공대학교 항공산업기술연구소 2001 航空宇宙産業技術硏究所 硏究誌 Vol.11 No.-

        본 연구에서는 타이어 sidewall부에 대한 내압 및 수직하중 그리고 시간에 따른 변형율 변화를 strain gage를 사용하여 측정하였다. 결과적으로 타이어에 최초 내압 작용 후 24시간이 지나면서 타이어의 strain 값이 안정되는 것을 확인하였으며 수직하중에 대한 실험 수행 시 1시간 이상 지난 후에 측정해야 하중작용 실험의 영향이 나타나지 않는 것을 확인하였다. 이로서 Strain gage를 이용한 실험 및 해석의 기반을 마련하였다. In this paper, variation of the strain on the radial tire sidewall with inflation pressure and vertical loading has been measured with respect to the time by experiment of method. As a result, the strain was stable after 24 hours, and vertical loading test must be done after I hour later from the prior loading test. The experiment was conducted to verify the deformation behavior experiment analyze method using strain gage. So the basis for the experiment and analysis of sidewall strain was established.

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