• Title/Summary/Keyword: surface alteration

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Assessment of decontamination of gutta-percha cone and the change of surface texture after rapid chemical disinfection (화학소독제 처리 후 가타파차 콘의 멸균 효과 및 표면 성상의 변화 평가)

  • Pang, Nan-Sim;Jung, Il-Young;Yu, Yoon-Jung;Kum, Kee-Yeon
    • Restorative Dentistry and Endodontics
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    • v.31 no.2
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    • pp.133-139
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    • 2006
  • The purposes of this study were firstly to identify the microbial species on gutta-percha (GP) cones exposed at outpatient clinics using polymerase chain reaction, and secondly to evaluate the rapid sterilization effect of two chemical disinfectants at chair side. It also evaluated the alteration of surface texture of GP cones after 5-min soaking into two chemical disinfectants. A total of 100 GP cones from two endodontic departments were randomly selected for microbial detection using PCR assay with universal primer. After inoculation on the sterilized GP cones with the same microorganism identified by PCR assay, they were soaked in two chemical disinfectants: 5% NaOCl and 2% chlorhexidine for 1, 3, 5, and 10 minutes. The sterilization effect was evaluated by turbidity and subculture. The change of surface textures using a scanning electron microscope was also examined after 5 min-soaking in two chemical disinfectants. Results showed that four bacterial species were detected in 17 GP cones, and all the species belonged to the genus Staphylococcus. Two chemical disinfectants were effective in sterilization with just 1 minute soaking. On the SEM picture of NaOCl-soaked GP cone, a cluster of cuboidal crystals was seen on the cone surface. Present data demonstrate that two chemical disinfectants are useful for rapid sterilization of GP cone just before obturation at chair side, while CHX-soaked GP cone has cleaner surface without crystal precipitation than that of NaOCl-treated cone.

Reconstruction of Nitrate Utilization Rate Change Based on Diatom-bound Nitrogen Isotope Values in the Central Slope Area of the Bering Sea during the Early Pleistocene (2.4-1.25 Ma) (플라이스토세 전기(2.4-1.25 Ma) 동안 베링해 중부 대륙사면 지역의 규조 골격내 유기물 질소동위원소 값에 의한 질산염 이용률의 변화 복원)

  • Kim, Sunghan;Khim, Boo-Keun
    • Ocean and Polar Research
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    • v.38 no.3
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    • pp.195-207
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    • 2016
  • Because the high latitude region in the North Pacific is characterized by high primary production in the surface water enriched with nutrients, it is important to understand the variation of surface water productivity and associated nutrient variability in terms of global carbon cycle. Surface water productivity change or its related nutrient utilization rate during the Northern Hemisphere Glaciation (NHG; ca. 2.73 Ma) has been reported, but little is known about such circumstances under gradual climate cooling since the NHG. Bulk nitrogen isotope (${\delta}^{15}N_{bulk}$) of sedimentary organic matter has been used for the reconstruction of nutrient utilization rate in the surface water. However, sedimentary organic matter experiences diagenesis incessantly during sinking through the water column and after burial within the sediments. Thus, in this study we examine the degree of nitrate utilization rate during the early Pleistocene (2.4-1.25 Ma) since the NHG, using the diatom-bound nitrogen isotope (${\delta}^{15}N_{db}$), which is known to be little influenced by diagenesis, from Site U1343 in the Bering slope area. ${\delta}^{15}N_{db}$ values range from ~0.5 to 5.5‰, which is lower than ${\delta}^{15}N_{bulk}$ values, but they vary with larger amplitude. Variation patterns between ${\delta}^{15}N_{db}$ values and biogenic opal concentration are generally consistent, which indicates that the nitrate utilization rate is closely related to opal productivity change in the surface water. A positive correlation between opal productivity and nitrate utilization rate was observed, which is different from the other high latitude regions in the North Pacific. The main reason for this contrasting relationship is that the primary production in the surface water at Site U1343 is influenced mostly by the degree of sea ice formation. Still, although concerns about diagenetic alteration have been avoided by using ${\delta}^{15}N_{db}$, the effects of the preservation state of biogenic opal and the species-dependent isotopic fractionation on ${\delta}^{15}N_{db}$ should be assessed in the future studies.

Numerical Simulation of the Asian Monsoon for the Mid-Holocene Using a Numerical Model (수치모델을 이용한 홀로세 중기의 아시아 몬순순환 변화 연구)

  • Kim, Seong-Joong;Lee, Bang-Yong;Park, Yoo-Min;Suk, Bong-Chool
    • Ocean and Polar Research
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    • v.27 no.3
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    • pp.289-297
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    • 2005
  • The change in global climate and Asian monsoon patterns during the mid-Holocene, 6000 years before present (6 ka), is simulated by a climate model at spectral truncations of T170 with 18 vertical layers, corresponding to grid-cell sizes of roughly 75km. The present simulation is forced with the observed monthly data of sea surface temperatures, and the specified concentration of atmospheric carbon dioxide, while in the mid-Holocene experiment, orbital parameters such as obliquity, precession, and eccentricity are changed to the 6ka conditions. Under such conditions, the precipitation associated with the summer monsoon is enhanced over a wider zonal band from the Middle East to Southeast Asia, while no significant alteration takes Place in winter. The monsoonal wind also increases over the Arabian Sea, showing the enhanced southwesterly wind during summer and northeasterly wind during winter. Overall, the showing of the Asian monsoon is enhanced during the mid-Holocene, especially in summer, which is consistent with the proxy estimates and other previous model simulations.

Mineralogy, Genesis and Potential of a New Tertiary Mineralized Zone in Yeongil Area, Korea (영일지역(迎日地域) 제삼기(第三紀) 신광화대(新鑛化帶)의 광물학적(鑛物學的) 특성(特性), 성인(成因) 및 그 잠재성(潛在性)에 관(關)한 연구(硏究))

  • Kim, Soo Jin;Noh, Jin Hwan
    • Economic and Environmental Geology
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    • v.10 no.2
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    • pp.53-66
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    • 1977
  • Epithermal Mn-Au-Ag deposits of subvolcanic type in the Yeongil area discovered by one (Soo Jin Kim) of the present authors was studied with emphasis on their mineralogy, genesis and future potential. Mineralization is genetically related to volcanic activities of the Tertiary Period, which have produced porphyritic rhyolite, granite porphyry, felsitic rhyolite and agglomerate. Ore deposits are closely associated with felsitic rhyolite. They occur as breccia-filling, veins, or networks. Mineralization is characterized by rhodochrosite-sulfide ores of breccia-type in the central zone, and sulfide ores of disseminated type in the outer zone. Sulfides consist mainly of pyrite and marcasite, with minor chalcopyrite, sphalerite, argentian tetrahedrite, galena and gold in the central zone, and of pyrite, marcasite and argentian tetrahedrite in the outer zone. Sulfides are generally not easily identified with naked eye because of their very fine-grained nature. Wall rock alteration zones are also developed around ore deposits over the large area. Occurrence of ore deposits and the nature of mineralization indicate that the uppermost portion of ore deposits are now exposed on the surface, and therefore, the main mineralized zones are expected in depth.

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A study on the alteration of general characteristics and therapeutic effect of GamiYeoldahansotang(加味熱多寒少湯) in patients with Atopic Dermatitis (가미열다한소탕(加味熱多寒少湯) 투여후 아토피 피부염 환자의 임상상 변화에 대한 연구)

  • Jung Hwan-Su;Lee Jin-Yong
    • The Journal of Pediatrics of Korean Medicine
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    • v.15 no.2
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    • pp.177-188
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    • 2001
  • Background : Atopic Dermatitis is thought to be a common and chronic relapsing inflammatory skin disease that probably results from allergic reaction. Because it make some serious problems in children, it is needed to treat and at least subside symptoms. Objective : The aim of this study was to evaluate the efficacy of GamiYeoldahansotang(加味熱多寒少湯) for treating Atopic Dermatitis and survey the general characteristics in children with Atopic Dermatitis. Method : Atopic Dermatitis with typical clinical symptoms were included in this study. Forty two patients were treated with hot water extract of GamiYeoldahansotang(加味熱多寒少湯) for four weeks. Clinical evaluation were made by Jacob T scoring system before and after treatment. Total Serum IgE, Eosinophil count were also conducted. Results : Reduction in body surface area was not observed. But significant reductions of severity scores before and after adminstration of GamiYeoldahansotang(加味熱多寒少湯) were observed in all of three groups: mind, moderate, severe. specially severe intensity group was very statistically significant.(p<0.05) Conclusion : We speculate that GamiYeoldahansotang(加味熱多寒少湯) has some therapeutic effects in mitigating the symptoms of Atopic Dermatitis.

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A Study of objectification and observations on the morphology of meridian point (경혈반응점의 형태학적 관찰과 객과화에 관한 연구)

  • Shin, M.H.;Eo, Y.K.;Lee, H.H.;Lee, S.R.;Park, H.C.;Jeong, D.M.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.05
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    • pp.309-312
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    • 1997
  • Meridian collteral and meridian points have been he base of acupunurre therapy. Also the theory have composed the main portion of oriental medicine. But the mechanism and scientific backgroud has not been completely eastablished, and the research on the objectification of diagonosis of meridian collateral and meridian points, and acupuncture therapy has been necessary nowday. A new understanding of value of oriental medicine has been increasing, the scientific understanding of meridian collateral and meridian points should have been examined. In this paper, we observed meridian point on the morphology for objectification and meridian visulalization we try to meridian point to use methylene blue and optical equipment of high power magnifications. The result of this study suggest that we can observe ruggedness part on body surface to be estimated meridian point. It is observed to have similarity each time of different meridian points. Also, we can observe part alteration of meridian points each time which observed to use method of electronic resistance of unsimilarity on the morphology.

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Transcriptional Responses of Human Respiratory Epithelial Cells to Nontypeable Haemophilus influenzae Infection Analyzed by High Density cDNA Microarrays

  • Lee, Ji-Yeon;Lee, Na-Gyong
    • Journal of Microbiology and Biotechnology
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    • v.14 no.4
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    • pp.836-843
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    • 2004
  • Nontypeable H. influenzae (NTHi), a Gram-negative obligate human pathogen, causes pneumonia, chronic bronchitis, and otitis media, and the respiratory epithelium is the first line of defense that copes with the pathogen. In an effort to identify transcriptional responses of human respiratory epithelial cells to infection with NTHi, we examined its differential gene expression using high density cDNA microarrays. BEAS-2B human bronchial epithelial cells were exposed to NTHi for 3 hand 24 h, and the alteration of mRNA expression was analyzed using microarrays consisting of 8,170 human cDNA clones. The results indicated that approximately 2.6% of the genes present on the microarrays increased in expression over 2-fold and 3.8% of the genes decreased during the 24-h infection period. Upregulated genes included cytokines (granulocyte-macrophage colony stimulating factor 2, granulocyte chemotactic protein 2, IL-6, IL-10, IL-8), transcription factors (Kruppel-like factor 7, CCAAT/enhancer binding protein $\beta$, E2F-1, NF-$\kappa$B, cell surface molecules (CD74, ICAM-1, ICAM-2, HLA class I), as well as those involved in signal transduction and cellular transport. Selected genes were further confirmed by reverse-transcription-PCR. These data expand our knowledge of host cellular responses during NTHi infection and should provide a molecular basis for the study of host-NTHi interaction.

Ultraviolet-B radiation sensitivities in rice plant: cyclobutane pyrimidine dimer photolyase activities and gene mutations

  • Hidema, Jun;Kumagai, Tadashi
    • Proceedings of the Korean Society of Plant Biotechnology Conference
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    • 2004.10a
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    • pp.29-34
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    • 2004
  • Reduction in stratospheric ozone layer increases the amount of ultraviolet-B radiation (UVB: 280-320 nm) that reaches the earth ’ s surface. UVB radiationcan damage plants, resulting in decrease in growth and productivity. UVB-augmentation studies have indicated that the sensitivity to UVB radiation in plants varies among the species and cultivars. However. there are no definitive answers for the mechanisms of UVB-resistance in higher plants and for bioengineering design and development of UVB-tolerant plants. We have been studying physiological and biochemical aspects of the effects of UVB radiation on growth and yield of rice COryza sativa LJ. aiming to clarify the mechanism of resistance to UVB radiationin rice. At this meeting. weintroduce our research as followed: (1) supplementary UVB radiation has inhibitory effects on the growth. yield and grain development of rice; (2) UVB sensitivity of rice varies widely among cultivars; (3) among Japanese rice cultivars. Sasanishiki. a leading variety in northeast Japan. is more resistant to UVB. while Norin 1. a progenitor of Sasanishiki. is less resistant; (4)UV-sensitive Norin 1 cultivar is deficient in photorepair of UVB-induced cyclobutane pyrimidine dimer (CPD). and this deficiency results from one amino acid residue alteration of CPD photolyase. These results suggest that spontaneously occurring mutation in CPD photolyase gene could lead to difference in UVB sensitivity in rice. and that CPD photolyase might be a useful target for improving UVB-sensitivity in rice by selective breeding or bioengineering of UVB-tolerant rice.

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Focal epithelial hyperplasia arising after delivery of metal-ceramic fixed dental prosthesis

  • Park, Min-Woo;Cho, Young-Ah;Kim, Soung-Min;Myoung, Hoon;Lee, Jong-Ho;Lee, Suk-Keun
    • The Journal of Advanced Prosthodontics
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    • v.6 no.6
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    • pp.555-558
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    • 2014
  • Focal epithelial hyperplasia (FEH) is a human papillomavirus (HPV)-induced alteration of the oral mucosa that presents with a clinically distinct appearance. While other HPV-infected lesions such as squamous papilloma, verruca vulgaris, and condyloma acuminatum involve the skin, oral mucosa, and genital mucosa, FEH occurs only in the oral mucosa. The affected oral mucosa exhibits multiple papules and nodules with each papule/nodule being flat-topped or sessile. The affected region resembles the normal color of oral mucosa rather than appearing as a white color since the epithelial surface is not hyperkeratinized. Almost all cases present with multiple sites of occurrence. This rare, benign epithelial proliferation is related to low-risk HPV, especially HPV-13 and -32, and is not transformed into carcinoma. We report a case of FEH that arose on the attached gingiva of an East Asian male adult related to prosthesis without detection of any HPV subtype in HPV DNA chip and sequencing.

Present State and Statistical Analysis of Stone Cultural Heritage by National Appointment in Republic of Korea (국내 국가지정 석조문화재의 현황과 통계분석)

  • Jun, Byung-kyu;Han, Min-su;Lee, Jang-jon;Song, Chi-young
    • 보존과학연구
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    • s.27
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    • pp.43-61
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    • 2006
  • In this study stone heritages of 533 which is to be investigated through the five years for national treasures and treasures from 2001 to 2005 have been analyzed by statistics for types of stone heritages and rocks, level of alteration in order to make full use of guiding principle in conservation management of stone heritages. The ratio of stone pagoda as a percentage of 34.5% in the stone heritages much higher than others and that is composed of granite(83.0%) in the igneous rock. In the weathering index of surface, a 37.5% of the national treasures were classified with the level 4 and46.3% of the treasure were the level 3 according to state. The present condition of organism distribution take up 30.6% for the level 3 and 22.1% for level 1. In structural stability index, a 40.6%of the national treasures and a 54.2% of treasure were ranked level 3.

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