• 제목/요약/키워드: Si Dan

검색결과 70건 처리시간 0.026초

Amentoflavone Acts as a Radioprotector for Irradiated v79 Cells by Regulating Reactive Oxygen Species (ROS), Cell Cycle and Mitochondrial Mass

  • Xu, Ping;Jiang, En-Jin;Wen, Si-Yuan;Lu, Dan-Dan
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권18호
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    • pp.7521-7526
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    • 2014
  • Radioprotective effects of amentoflavone were investigated by examining cell viability, apoptosis, cell cycling concentrations of intracellular ROS (reactive oxygen species), and relative mitochondrial mass by flow cytometry after $^{60}Co$ irradiation. Pretreatment with amentoflavone 24 hours prior to 8 Gy $^{60}Co$ ${\gamma}$-ray irradiation significantly inhibited apoptosis, promoted the G2 phase, decreased the concentration of ROS and mitochondrial mass. These results collectively indicate that amentoflavone is an effective radioprotective agent.

Polysilane 유도체의 합성과 그 응용 (Preparation and Application of Polysilane Derivatives)

  • 강두환
    • 공업화학
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    • 제1권1호
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    • pp.1-10
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    • 1990
  • 용매에 가용성이고 또한 성형이 가능한 각종 polysilane 유도체가 합성되면서 1980년대 이래 새로운 소재로서 많은 관심을 끌게 되었다. 저분자량 oligomer, 고리화합물, 고분자량의 polysilane 유도체를 합성하는 방법을 소개하고 Si-Si 결합과 또한 Si 원자에 치환된 치환기의 종류에 따른 광화학반응 특성을 알아본다. 또한 polysilane은 탄화규소섬유의 precursor로, microelectronics에 있어서 photoresist로, photoconductor로, 그리고 free radical 중합반응에서 photoinitiator로 이용될 수 있는데 이들의 이용에 대한 최근의 연구결과들을 요약하여 소개한다.

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방열기판 전극형성 기술 동향

  • 김단비;김지원;엄누시아;임재홍
    • 세라미스트
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    • 제21권2호
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    • pp.83-88
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    • 2018
  • There is close relation between the heat generation and the performance of electronic device. The durability and efficiency of the device are degraded due to heat generation. It is necessary to release the generated heat from an electronic device. Based on demands of the printed circuit board (PCB) manufacturing, the robust and reliable plating technique of PCB is necessary. In this study, we review various methods for improving the heat sink property. These methods were considered to enhance the adhesion between ceramic substrate as heat sink and metal layer as electrode.

치주처치를 위한 기구의 반복 사용시 도재관 변연부 변화에 관한 입체 및 주사탐침현미경적 연구 (The Stereomicroscope and SPM Study on the Marginal Change of Porcelain Crown in Various Repeated Instrumentations for Periodontal Therapy)

  • 이시철;정진형;임성빈
    • Journal of Periodontal and Implant Science
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    • 제30권2호
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    • pp.455-472
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    • 2000
  • Instrumentation for periodontal therapy may induce marginal damage which increases plaque accumulation and result in periodontal disease. But there have not been many reports of instrumentations on the artificial crown so far. Therefore this study is conducted to evaluate the effects of various repeated instrumentations on the porcelain crown marginal portion. Of the 10 extracted periodontally diseased maxillary first premolars, were 12 proximal surface used in this study. The finishing line of the preparation was placed on the root surface below CEJ and then the crown was cast and cemented in usual manner. Every 4 surfaces of the 3 instruments-curet, ultrasonic scaler, and ultrasonic curet- is used. and four samples used in each instruments. The relevant procedures and measurements were repeated 3 times in each surfaces. Marginal gap is measured by the microscope and surface roughness, Scannig Probe Microscope. Measurements are made at 5 points in each surfaces, making 20 points in each instrument. The results evaluated statistically were as follows 1. As instrumentation was repeated, both marginal gap and roughness were increased in all group 2. In the hand curet, marginal gap was increased every instrumentation and roughness was increased after second. 3. In the ultrasonic scaler, both marginal gap and roughness were increased every instrumentation. 4. In the ultrasonic curet, marginal gap was increased after third instrumentation and roughness was increased after second. 5. Marginal gap and roughness used by the ultrasonic curet were lower than the others and no difference was seen between the hand curet and ultrasonic scaler From the results of this study, the ultrasonic curet was useful in some aspect, but careful instrumentation was needed. Furthermore it was important to minimize the instrumentation through complete periodontal therapy before setting and adequate plaque control.

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천정기보단(天精氣保丹)의 자외선에 의한 세포 손상 억제 효과 (Protective Effect of Cheonjeongkibo-Dan UV-Induced Cellular Damage in Human Dermal Fibroblast)

  • 이강태;박시준;이정로;이광식;김대성;문연자;이건국;우원홍
    • 동의생리병리학회지
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    • 제24권6호
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    • pp.950-955
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    • 2010
  • In this study, we prepared CheonJeongKiBo-Dan(7 oriental medicinal plants, 7OMP: Astragalus Membranaceus root, Panax Ginseng root, Glycyrrhiza Glabra (licorice) root, Schizandra Chinensis fruit, Polygonatum Odoratum, Rehmannia Glutinosa root, Paeonia Albiflora root) by extracting them in one reactor and studied its efficacies on skin. UV irradiation has been suggested as a major cause of photoaging in skin. In order to investigate protective effects against UV-B induced cellular damage, 7OMP was extracted with 70% ethanol and dissolved in DMSO. The protective effect was detected by MTT assay, reactive oxygen species (ROS) generation, phosphorylation of ATR and p53 in human dermal fibroblast cell system after UV-B irradiation. 7OMP reduced UV-B-induced cellular damage in HDFs cells, and inhibited ROS generation. UV-B-induced toxicity accompanying ROS production and the resultant DNA damage are responsible for activation of ATR, p53 and Bad. In this study, 7OMP hampered phosphorylations of ATR and p53 in human dermal fibroblasts. Therefore, 7OMP may be protective against UV-induced skin photoaging.

Breeding and characterization of a long shelf-life cultivar 'DanBi 7Ho' by mono-mono crossing in Pleurotus eryngii

  • Kim, Min Keun;Sim, Soon Ae;Park, Ji Hye;Ryu, Jae San;Choi, Si Lim;Hong, Kwang Pyo
    • 한국버섯학회지
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    • 제16권3호
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    • pp.140-146
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    • 2018
  • Pleurotus eryngii is one of the most commercially important mushrooms cultivated in Korea. However, the shelf-life of the fruiting body is short, limiting its export. A new hybrid strain H17 of P. eryngii was developed to extend the shelf-life by mono-mono crossing between monokaryotic strains derived from DanBi and KNR2774. Although the cultivation period of H17 was slightly longer than that of the reference cultivar Kenneutari No.2, the quality did not change and remained normal after a period of 65.0 days at $4^{\circ}C$. This result was significantly different from that of the reference cultivar Kenneutari No.2. Analysis of the genetic characteristics of the new hybrid strain H17 revealed a different profile from that of the parental and reference cultivars when random amplification of polymorphic DNA (RAPD) primers was used. These results demonstrate that H17 is a new cultivar with improved storability after harvesting.

Oncomodulin/Truncated Protamine-Mediated Nogo-66 Receptor Small Interference RNA Delivery Promotes Axon Regeneration in Retinal Ganglion Cells

  • Cui, Zhili;Kang, Jun;Hu, Dan;Zhou, Jian;Wang, Yusheng
    • Molecules and Cells
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    • 제37권8호
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    • pp.613-619
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    • 2014
  • The optic nerve often suffers regenerative failure after injury, leading to serious visual impairment such as glaucoma. The main inhibitory factors, including Nogo-A, oligodendrocyte myelin glycoprotein, and myelin-associated glycoprotein, exert their inhibitory effects on axonal growth through the same receptor, the Nogo-66 receptor (NgR). Oncomodulin (OM), a calcium-binding protein with a molecular weight of an ~12 kDa, which is secreted from activated macrophages, has been demonstrated to have high and specific affinity for retinal ganglion cells (RGC) and promote greater axonal regeneration than other known polypeptide growth factors. Protamine has been reported to effectively deliver small interference RNA (siRNA) into cells. Accordingly, a fusion protein of OM and truncated protamine (tp) may be used as a vehicle for the delivery of NgR siRNA into RGC for gene therapy. To test this hypothesis, we constructed OM and tp fusion protein (OM/tp) expression vectors. Using the indirect immunofluorescence labeling method, OM/tp fusion proteins were found to have a high affinity for RGC. The gel shift assay showed that the OM/tp fusion proteins retained the capacity to bind to DNA. Using OM/tp fusion proteins as a delivery tool, the siRNA of NgR was effectively transfected into cells and significantly down-regulated NgR expression levels. More importantly, OM/tp-NgR siRNA dramatically promoted axonal growth of RGC compared with the application of OM/tp recombinant protein or NgR siRNA alone in vitro. In addition, OM/tp-NgR siRNA highly elevated intracellular cyclic adenosine monophosphate (cAMP) levels and inhibited activation of the Ras homolog gene family, member A (RhoA). Taken together, our data demonstrated that the recombinant OM/tp fusion proteins retained the functions of both OM and tp, and that OM/tp-NgR siRNA might potentially be used for the treatment of optic nerve injury.

SCANNING ELECTRON MICROSCOPY ANALYSIS OF FUEL/MATRIX INTERACTION LAYERS IN HIGHLY-IRRADIATED U-Mo DISPERSION FUEL PLATES WITH Al AND Al-Si ALLOY MATRICES

  • Keiser, Dennis D. Jr.;Jue, Jan-Fong;Miller, Brandon D.;Gan, Jian;Robinson, Adam B.;Medvedev, Pavel;Madden, James;Wachs, Dan;Meyer, Mitch
    • Nuclear Engineering and Technology
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    • 제46권2호
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    • pp.147-158
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    • 2014
  • In order to investigate how the microstructure of fuel/matrix-interaction (FMI) layers change during irradiation, different U-7Mo dispersion fuel plates have been irradiated to high fission density and then characterized using scanning electron microscopy (SEM). Specifially, samples from irradiated U-7Mo dispersion fuel elements with pure Al, Al-2Si and AA4043 (~4.5 wt.%Si) matrices were SEM characterized using polished samples and samples that were prepared with a focused ion beam (FIB). Features not observable for the polished samples could be captured in SEM images taken of the FIB samples. For the Al matrix sample, a relatively large FMI layer develops, with enrichment of Xe at the FMI layer/Al matrix interface and evidence of debonding. Overall, a significant penetration of Si from the FMI layer into the U-7Mo fuel was observed for samples with Si in the Al matrix, which resulted in a change of the size (larger) and shape (round) of the fission gas bubbles. Additionally, solid fission product phases were observed to nucleate and grow within these bubbles. These changes in the localized regions of the microstructure of the U-7Mo may contribute to changes observed in the macroscopic swelling of fuel plates with Al-Si matrices.

Preliminary Evaluation of the in vitro Efficacy of 1, 2-di (Quinazolin-4-yl) Diselane against SiHa Cervical Cancer Cells

  • Huang, Yin-Jiu;Zhang, Yu-Yuan;Liu, Gang;Tang, Jie;Hu, Jian-Guo;Feng, Zhen-Zhong;Liu, Fang;Wang, Qi-Yi;Li, Dan
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권15호
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    • pp.6301-6306
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    • 2014
  • Cervical cancer is one the most common malignancies among females. In recent years, its incidence rate has shown a rising trend in some countries so that development of anticancer drugs for cervical cancer is an urgent priority. In our recent anticancer drug discovery screen, 1, 2-di (quinazolin-4-yl)diselane (LG003) was found to possess wide spectrum anticancer efficacy. In the present work, the in vitro anticancer activity of LG003 was evaluated in the SiHa cervical cancer cell line. Compared with commercial anticancer drugs 10-hydroxycamptothecin, epirubicin hydrochloride, taxol and oxaliplatin, LG003 showed better anticancer activity. Furthermore, inhibition effects were time- and dose-dependent. Morphological observation exhibited LG003 treatment results in apoptosis like shrinking and blebbing, and cell membrane damage. Lactate dehydrogenase release assay revealed that LG003 exerts such effects in SiHa cells through a physiology pathway rather than cytotoxicity, which suggests that title compound LG003 can be a potential candidate agent for cervical cancer.