• Title/Summary/Keyword: MgB2

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평판 디스플레이의 효율화를 위한 진공 인-라인 실장기술에 관한 연구

  • 권상직;홍근조;성정호;이창호;권용범
    • Proceedings of the Korean Vacuum Society Conference
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    • 2000.02a
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    • pp.45-45
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    • 2000
  • PDP, FED, 그리고 VFD와 같은 마이크로 전자디스플레이 장치를 제작하기 위한 가장 중요한 기술중에 하나인 패널 내를 고진공으로 만드는 것과 초기의 진공을 유지하는 것이다. PDP 디스플레이는 전면판과 후면판으로 구성되어 있다. 전면판은 ITO전극, 절연체 그리고 MgO보호막으로 구성되어 있으며, 후면판은 어드레스 전극, 반사층, 격벽, 그리고 형광체층이 있다. 기존의 방식은 대기에서 프릿 글라스를 이용하여 두 장의 유리를 봉입하고, 후면판 모서리 부분에 있는 구멍에 배기 글라스 튜브를 붙이고, 튜브를 통해서 배기하고, 플라즈마 가스를 채우고, 최종적으로 tip-off를 한다. 이러한 기존의 방식을 통해서는 배기 컨덕턴스의 한계로 얻을 수 있는 초기 진공도에 한계가 있다. 아울러 두 장의 유리사이는 150$\mu$m 정도의 간격으로 되어 있고, 이웃한 격벽사이는 320$\mu$m 정도의 미세한 공간이 주어지는 구조가 컨덕턴스를 저하시킨다. 이와 같은 초기 진공도의 한계성을 극복하기 위한 연구로서, PDP 패널을 구성하는 두 장의 글라스를 진공 챔버내에서 IR heater를 이용하여 실장하였다. 대개 PbO, ZnO, SiO2,, 그리고 B?로 구성된 프릿 글라스를 대기에서 전면판에 dispensing하고 가소한다. 그리고 프릿 글라스가 형성된 전면판과 후면판을 loading, align 한 다음, 2 10-7torr까지 펌핑한 후 heating, holding 그리고 cooling 공정을 수행하므로 써 두 장의 유리를 실장하였다. 그러나 온도의 non-uniformity, 프릿 성분에 따라서 crack과 기포문제가 진공 실장과정에서 발생하였다. 이와 같은 문제를 개선하기 위해 프릿 글라스의 새로운 조성과 온도 uniformity를 유지하므로써, 프릿 글라스의 기포와 crack 발생없이 재현성 있게 진공 실장하였다. Leak channel 형성유무를 검증하기 위하여 챔버 자체의 펌핑 속도와 제작된 패널의 펌핑 속도를 비교하므로써, leak channel형성 유무를 평가할 수 있는 방법을 이용하였다. 이와 같은 방법을 이용하여, crack 또는 기포가 있는 패널은 leak channel을 형성하여 패널내의 진공을 유지할 수 없음을 검증하였고, crack 또는 기포가 없는 패널은 leak channel없이 패널내의 진공을 유지할 수 있음을 검증하였다. 결과적으로 진공 인-라인 실장시 가장 중요한 요인인 프릿의 변화를 분석하므로써, 고진공을 요구하는 FPD(PDP, FED, VFD)에 적합하게 적용할 수 있으며, 아울러 실장시 진공도를 개선하므로 패널내부의 오염을 최소화하여 디스필레이로서의 효율을 극대화할 수 있을 것이다.

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NEUROTOXICITY OF TRIMETHYLTIN IN HIPPOCAMPUS: A HYPEREXCITATORY TOXICITY

  • Chang, Louis W.
    • Toxicological Research
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    • v.6 no.2
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    • pp.191-204
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    • 1990
  • Trimethyltin (TMT) induced lesions in the rat hippocampal formation was reviewed. Adult rats were treated with a single dose of 6.0 mg TMT/kg b.w. and were sacrificed between 3-60 days following exposure. On the hippocampal formation, the granule cells of fascia dentata showed early changes which subsided considerably at a later time when the destruction of the pyramidal neurons of the Ammon's horn became increasingly pronounced with time, leading to severe destruction of the structure. It is interesting to note that there was an inverse relationship of pathological involvement between the f.d. granule cells and the Ammon's horn neurons; i.e., when there was a large sparing of the granule cells. there was an extensive damage to the Ammon's horn and vice versa. This inverse relationship was also true between the $CA_3$neurons and the $CA_{1,2}$neurons in the Ammon's horn. Progressive zinc loss, as demonstrated by Timm's method, on the Mossy fibers was also observed. Similar Mossy fiber zinc depletion has been demonstrated in electrical stimulatory excitation condition of the perforant path to the hippocampus. Depletion of corticosterone, an inhibitor to the hippocampal neurons, by means of adrenalectomy will exaggerate the TMT induced hippocampal lesion. Neonatal study revealed that a unique degenerative pattern of the Ammon's horn could be established in accordance with exposure to TMT at specific maturation periods of the fippocampal formation: increasing destruction of the Ammon's horn with increasing synaptogenesis between the f.d. granule cells and the Ammon's horn neurons. Thus it is apparent that the damage of the Ammon's horn, upon exposure to TMT, may depend on the integrity and functional state of the f.d. granule cells. A hyperexcitory scheme and mechanism as the toxicity basis of TMT in the hippocampal formation is proposed and discussed.

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Nutrients In Coastal Water Of Korea During Summer Of 1977 (여름철 한국 연안해수중의 영양염 함량)

  • Lee, Kwang Woo;Kwak, Hi-Sang;Lee, Soo Hyung;Lee, Dong Soo
    • 한국해양학회지
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    • v.13 no.2
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    • pp.17-25
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    • 1978
  • General water quality parameters were measured, as a base-line study, for possible water pollution problems in the coastal waters of some important harbors and near-sea industrial complexes all around coastal zones of Korea from June 1 to October 15, 1977. The areas surveyed were near Mugho-Samcheog, Ulsan, Jinhae-Masan, Yeosu-Gwangyang, Mogpo, Gunsan and Incheon. Among the surveyed coastal areas, the Ulsan and the Jinhae-Masan areas showed high levels of dissolved oxygen, pH, COD and nutrients. Particularly, the surface waters of the Ulsan inner bay represented COD 15.6mg/l and NO$\sub$2/-N 110$\mu\textrm{g}$/l. The surface layer of the Masan bay displayed pH 8.92 and NO$\sub$3/-N 372$\mu\textrm{g}$/l, while 309$\mu\textrm{g}$/l of PO$\sub$4/-P was recorded in the surface of the Haengam bay. In general it is shown that some coastal areas are presenting signs of pollution from man's activities.

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Bacterial attachment and penetration to Tetracycline-treated resorbable and nonresorbable membranes for GTR (테트라싸이클린 처리된 흡수성 및 비흡수성 조직유도재생술용 막에의 세균부착과 침투양상)

  • Lee, Ho-Jae;Chung, Hyun-Ju
    • Journal of Periodontal and Implant Science
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    • v.27 no.1
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    • pp.19-43
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    • 1997
  • The barrier membranes for GTR procedure could be affected bY bacterial contamination after exposure to oral environment. This study was done to evaluate whether the tetracycline impregnated barrier membranes could inhibit bacterial attachment and penetration into membranes. The resorbable membrane(polylactic and polyglycolide copolymer, $Resolute^{(R)}$, W.L Gore and Associates, Inc..USA) and the non-resorbable membrane(e-PTFE; Gore-TexTM, W.L. Gore & Associates, Inc.,USA) were cut into 4mm discs and trated with 5% tridodecylmethylammonium chloride solution in ethanol and dried in air. The membranes were immersed in tetracycline(TC) solution (100mg/ml, pH 8.0) and dried. To the maxillary canine-premolar region in six periodontally healthy volunteers, removable acrylic devices were inserted, on which 8 cylindrical chambers were glued with TC impregnated and non-impregnated discs, the membrane discs were examined for bacterial attachment and penetration, and structural changes under SEM and LM. From the 1st day to the 7th day, membranes showed bacterial plaque formation composed of cocci and rods. Thereafter, filamentous bacteria appeared and the plaque thickness increased. The TC impregnated e-PTFE membranes showed less bacterial attachment and delayed in bacterial plaque maturation than non-treated membranes. As for bacterial penetration, the TC impregnated e-PTFE membranes showed superficial invasion and infrequent presence of bacteria in unexposed inner surface at the 4th week. while the non-treated e-PTFE membranes showed deep bacterial invasion at the 2nd week and frequent presence of internal bacteria at the 4th week. The resorbable membranes started to be resorbed at the 2nd week and were perforated at the 4th week, regardless of TC treatment. In conclusion, bacterial plaque formation and penetration was efficiently delayed in TC impregnated e-PTFE membranes, whereas resorbable membranes were similar in bacterial invasion due to membrane degradation and perforation, regardless of TC treatment.

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Quality Characteristics and Antioxidative Activity of Garlic Pickles Prepared with Persimmon Vinegar and Maesil (Japanese Apricot) Juice (감식초와 매실액을 첨가한 마늘 피클의 품질 특성 및 항산화성)

  • Song, Mi-Ran;Kim, Mee-Jeong;Kwon, Oh-Yoon;Kim, Hye-Ran;Kim, Mee-Ree
    • Journal of the East Asian Society of Dietary Life
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    • v.19 no.6
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    • pp.981-986
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    • 2009
  • The quality characteristics and antioxidative activity of garlic pickles prepared with persimmon vinegar with or without Maesil (Japanese apricot) juice were investigated. Heat treated garlic cloves ($110^{\circ}C$, 5 min and then rapidly cooling) were salted with NaCl and $CaCl_2$, and then soaked in pickling solution, and stored at $20^{\circ}C$. The pH of the garlic pickles initially ranged from 2.36~3.24, after which the pH slightly increased to 3.22~4.13 during storage, while the acidity was decreased to 1~1.97. Throughout the entire storage periods, the acidity of the garlic pickle containing persimmon vinegar and Maesil was the highest (1.97%). The hardness of the control sample (non heated garlic) decreased during storage, whereas the hardness of all the heat treated groups did not change after 21 days of storage. Moreover, the chewiness of the persimmon vinegar+Maesil group was the highest among the groups. The Hunter color L value of garlic pickles decreased during storage, while the b value (yellowness) increased for all groups except the two persimmon groups. The $IC_{50}$ of the DPPH radical scavanging activity of garlic pickles at 5 day of storage was 85.98~97.81 mg/mL. However, the antioxidative activity of garlic pickles gradually increased with longer storage times. The persimmon vinegar+Maesil group showed the highest antioxidative activity. Results from the sensory evaluation showed that scores of flavor, taste and over-all preference were higher for the persimmon vinegar+Maesil group than the other groups (p<0.05).

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Optimization of Preparation Conditions of Houttuynia cordata Beverage Containing Saururus chinensis and Polygonatum odoratum by Sensory Evaluation and Response Surface Methodology (관능 평가 및 반응 표면 분석에 의한 삼백초와 둥굴레 가미 어성초 음료의 제조 조건 최적화)

  • Seung, Suk-Kyung;Chang, Kyung-Ho;Joung, Kyung-Hee;Kim, Ae-Jung
    • Journal of the East Asian Society of Dietary Life
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    • v.18 no.6
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    • pp.1072-1080
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    • 2008
  • The optimization of the addition ratios of Houttuynia cordata, Saururus chinensis, and Polygonatum odoratum var. pluriflorum hot water extract to Houttuynia cordata beverage was evaluated by applying response surface methodology. The quality characteristics of a selected best product were investigated. Sweet, savory, and fishy taste, and overall acceptability were optimized by response surface methodology using a central composite design. The concentration of effect of Houttuynia cordata, Saururus chinensis, and Polygonatum odoratum var. pluriflorum hot water extract was modeled using an equation. Hot water extracts of Houttuynia cordata ($1.75{\sim}1.89%$), Saururus chinensis ($1.03{\sim}1.04%$), and Polygonatum odoratum var. pluriflorum ($2.17{\sim}2.31%$) represented the optimal concentration conditions to obtain the best taste. The physical and chemical characteristics of the beverage manufactured at optimized conditions were pH 4.18, soluble solids 0.41 $^{\circ}Brix$, total acidity 0.21%, color value ($L^*$ value 40.08, $a^*$ value 4.53, and $b^*$ value 10.69), total polyphenol 54.63 mg/L, and electron donating ability 26.98%.

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An ${\beta}$-1,4-Xylanase with Exo-Enzyme Activity Produced by Paenibacillus xylanilyticus KJ-03 and Its Cloning and Characterization

  • Park, Dong-Ju;Lee, Yong-Suk;Chang, Jie;Fang, Shu-Jun;Choi, Yong-Lark
    • Journal of Microbiology and Biotechnology
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    • v.23 no.3
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    • pp.397-404
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    • 2013
  • Paenibacillus xylanilyticus KJ-03 was isolated from soil samples obtained from a field with Amorphophallus konjac plants. A gene encoding xylanase was isolated from KJ-03 and cloned using a fosmid library. The xynA gene encodes xylanase; it consists of 1,035 bp and encodes 345 amino acids. The amino acid sequence deduced from the P. xylanilyticus KJ-03 xylanase showed 81% and 69% identities with those deduced from the P. polymyxa E681 and Paenibacillus sp. HPL-001 xylanases, respectively. The xynA gene comprises a single domain, consisting of a catalytic domain of the glycosyl hydrolase (GH) 10 family. The xynA gene was expressed in Escherichia coli BL21 (trxB), and the recombinant xylanase was purified by Niaffinity chromatography. The purified xylanase showed optimum activity with birchwood xylan as a substrate at $40^{\circ}C$ and pH 7.4. Treatment with $Mg^{2+}$ and $Li^+$ showed a slight decrease in XynA activity; however, treatment with 5 mM $Cu^{2+}$ completely inhibited its activity. The results of the thin layer chromatography analysis indicated that the major hydrolysis product was xylobiose and small amounts of xylose and xylotriose. XynA showed increased activity with oat spelt xylan and birchwood xylan, but showed only slight activity with locust bean gum.

Effects of Subchronic Treatment with $AT_{1}$ Receptor Antagonists on Endothelium-dependent and -independent Relaxatio

  • Lee, Byung-Ho
    • Archives of Pharmacal Research
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    • v.19 no.5
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    • pp.390-395
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    • 1996
  • To investigate whether $AT_{1}$ receptor antagonists are acting by increasing endothelium-de-pendent and -independent relaxation of aortas in normotensive rats, $AT_{1}$ receptor antagonists, losartan and KR-30988, and angiotensin converting enzyme inhibitor, captopril, were orally administered for two weeks (50 mg/kg, b.i.d.). THe blood pressure, heart rate and body weight were not significantly changed by losartan, KR-30988 and captopril compared to the control group. In aortic preparations, the $pD_{2}$ of KR-30988 for ACh-induced relaxation was 8.33 $\pm$ 0.16, significantly (p <0.05) lower than that of control group $(7.71 \pm 0.15)$. ACh-induced relaxation was significantly increased on losartan-treated group (p<0.01) at $10^{-6}$ M of ACh, and in captopril-treated group (p<0.05) at the range of $10^{-7}$ -$10^{-5}$ M of ACh. The $pD_{2}$ values for histamine-induced relaxatio of losartan, KR-30988 and captopril were 5.57 $\pm$ 0.10, 5.85 $\pm$ 0.21 and 5.60 $\pm$ 0.01, respectively, with significant differences in all groups (p<0.01) compared to that of control group (5.13 $\pm$ 0.09). ACh-induced relaxations of aortic preparations were not changed by pretreatment of indomethacin ($10_{-5}$ M), and completely bolcked by pretreatment of L-NAME $(10_{-5}M)$ in all groups. Sodium nitroprusside-induced relaxations were not significantly changed by all drugs tested in this experiments. These results suggest that $AT_{1}$ receptor antagonists, losartan and KR-30988, enhance the endothelium-dependent relaxatio on aortic preparations through the release of, or increase sensitivity, to nitric oxide in nor-motensive rats.

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RE-ENDOTHELIZATION OF MICROVASCULAR ANASTOMOSIS IN DIABETIC RAT FEMORAL ARTERY ; A SCANNING ELECTRON MICROSCOPIC STUDY (당뇨백서(糖尿白鼠)의 대퇴동맥(大腿動脈) 미세혈관문합(微細血管吻合) 후(後) 내피세포(內皮細胞)의 재생(再生)에 관한 연구(硏究))

  • Ryu, Sun-Youl;Kim, Young-Jae
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.14 no.1_2
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    • pp.77-88
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    • 1992
  • Recently, diabetic patients are increasing in the field of microvascular surgery. Diabetes melltius is known to be related to arterial damage, platelet malfunction and thrombus formation. After microvascular anastomosis, delayed repair and vascular occlusion occurred more frequently in diabetic state. This study was performed to investigate the patency rate and process of endothelial healing after microvascular anastomosis of femoral artery in diabetic rat by scanning electron microscope. The animals were divided into two groups, 20 diabetic-induced and 20 non-diabetic groups. Diabetes was induced with a injection of Streptozotocin(50mg/kg b.w., Sigma Chemical Co.) to tail vein. The results obtained were as follows: 1. Macroscopically, anastomotic site was intact except a few cases showed minimal inflammatory sign around the wound site. But the inflammatory change was frequently occurred in diabetic-induced group. 2. The patency rate was 95% (19/20) in non-diabetic group and 65% (13/20) in diabetic-induced group. 3. In the non-diabetic group, anstomotic region was mostly endothelized by the alignment along the long axis of vessel but stitchs were not covered with endothelial cells. The thichkening of vessel wall was not observed. 4. In the diabetic-induced group, anastomotic region was not endothelized but covered with blood cellular components and connective tissue instead of endothelial cells. The thickening of the vessel wall was prominent in some diabetic-induced rats. These results suggest that diabetes was related to delayed regeneration of endothelium of vessels after microsurgical anastomosis.

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The Effect of Red Ginseng Extract on Inflammatory Cytokines after Chemotherapy in Children

  • Lee, Jae-Min;Hah, Jeong-Ok;Kim, Hee-Sun
    • Journal of Ginseng Research
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    • v.36 no.4
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    • pp.383-390
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    • 2012
  • Ginseng has been used as an herbal medicine, widely used in Asian countries, for long time. Recently, beneficial effects for immune functions of Korean red ginseng (KRG) have been reported in adults. This study was performed to investigate the effects of ginseng on immune functions in children after cessation of chemotherapy or stem cell transplantation for advanced cancer. Thirty patients, who were diagnosed and treated for leukemia and solid cancer at the department of pediatrics and adolescence of the Yeungnam University Hospital from June 2004 to June 2009, were enrolled for the study. The study group consisted of 19 patients who received KRG extract (60 mg/kg/d) for 1 yr and 11 patients who did not receive KRG extract were the control group. Blood samples were collected every 6 mo. Immune assays included circulating lymphocyte subpopulation, serum cytokines (IL-2, IL-10, IL-12, TNF-alpha, and IFN-gamma), and total concentrations of serum IgG, IgA, and IgM subclasses. Age at diagnosis ranged from 2 mo to 15 yr (median 5 yr). Nine patients received stem cell transplantation. The cytokines of the KRG treated group were decreasing more rapidly than that of the control group. Lymphocyte subpopulations (T cell, B cell, NK cell, T4, T8, and T4/T8 ratio) and serum immunoglobulin subclasses (IgG, IgA, and IgM) did not show significant differences between the study and the control groups. This study suggests that KRG extract might have a stabilizing effect on the inflammatory cytokines in children with cancer after chemotherapy.