• Title/Summary/Keyword: natural science high school

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Dehydrocoupling of Bis(silyl)alkylbenzenes to Network Polysilanes, Catalyzed by Group 4 Metallocene Combination

  • Kim, Myoung-Hee;Lee, Jun;Moo, Soo-Yong;Kim, Jong-Hyun;Ko, Young Chun;Woo, Hee-Gweon
    • Journal of Integrative Natural Science
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    • v.3 no.1
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    • pp.1-6
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    • 2010
  • Bis(silyl)alkylbenzenes such as bis(1-sila-sec-butyl)benzene (1) and 2-phenyl-1,3-disilapropane (2) were synthesized in high yields by the reduction of the corresponding chlorosilanes with $LiAlH_4$ in diethyl ether. The dehydrocoupling of 1 and 2 was performed using group IV metallocene complexes generated in situ from $Cp_2MCl_2$/Red-Al and $Cp_2MCl_2$/n-BuLi (M = Ti, Hf), producing two phases of polymers. The TGA residue yields of the insoluble polymers were in the range of 64-74%. The molecular weights of the soluble polymers produced ranged from 700 to 5000 ($M_w$ vs polystyrene using GPC) and from 500 to 900 ($M_w$ vs polystyrene using GPC). The dehydropolymerization of 1 and 2 seemed to initially produce a low-molecular-weight polymer, which then underwent an extensive cross-linking reaction of backbone Si-H bonds, leading to an insoluble network polymer.

A Microscopic Study on Treatment Mechanism of Acid Mine Drainage by Porous Zeolite-slag Ceramics Packed in a Column Reactor System (컬럼반응조 내 충진된 다공성 zeolite-slag 세라믹에 의한 산성광산배수의 처리기작에 대한 미세분석 연구)

  • Yim, Soo-Bin
    • Journal of Korean Society of Water Science and Technology
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    • v.26 no.6
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    • pp.13-26
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    • 2018
  • This research was conducted to elucidate the removal mechanism of heavy metals and sulfate ion from acid mine drainage(AMD) by porous zeolite-slag ceramics (ZS ceramics) packed in a column reactor system. The average removal efficiencies of heavy metals and sulfate ion from AMD by the 1:3(Z:S) porous ZS ceramics in the column reactor under the HRT condition of 24 hours were Al 97.5%, As 98.8%, Cd 86.1%, Cu 96.2%, Fe 99.7%, Mn 64.1%, Pb 97.2%, Zn 66.7%, and $SO_4{^{2-}}$ 76.0% during 121 days of operation time. The XRD analysis showed that the ferric iron from AMD could be removed by adsorption and/or ion-exchange on the porous ZS ceramics. In addition it was known that Al, As, Cu, Mn, and Zn could adsorb or coprecipitate on the surface of Fe precipitates such as schwertmannite, ferrihydrite, or goethite. The EDS analysis revealed that Al, Fe, and Mn, which were of relatively high concentration in the AMD, would be adsorbed and/or ion-exchanged on the porous ZS ceramics and also exhibited that Al, Cu, Fe, Mn, and Zn could be precipitated as the form of metal hydroxide or sulfate and adsorbed or coprecipitated on the surface of Fe precipitates. The microscopic results on the porous ZS ceramics and precipitated sludge in a column reactor system suggested that the heavy metals and sulfate ion from AMD would be eliminated by the multiple mechanisms of coprecipitation, adsorption, ion-exchange as well as precipitation.

Expression of FMD virus-like particles in yeast Hansenula polymorpha and immunogenicity of combine with CpG and aluminum adjuvant

  • Jianhui Zhang;Jun Ge;Juyin Li;Jianqiang Li;Yong Zhang;Yinghui Shi;Jiaojiao Sun;Qiongjin Wang;Xiaobo Zhang;Xingxu Zhao
    • Journal of Veterinary Science
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    • v.24 no.1
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    • pp.15.1-15.13
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    • 2023
  • Background: Inactivated vaccines are limited in preventing foot-and-mouth disease (FMD) due to safety problems. Recombinant virus-like particles (VLPs) are an excellent candidate for a novel vaccine for preventing FMD, given that VLPs have similar immunogenicity as natural viruses and are replication- and infection-incompetent. Objectives: The 3C protease and P1 polyprotein of type O FMD virus (FDMV) was expressed in yeast Hansenula polymorpha to generate self-resembling VLPs, and the potential of recombinant VLPs as an FMD vaccine was evaluated. Methods: BALB/c mice were immunized with recombinant purified VLPs using CpG oligodeoxynucleotide and aluminum hydroxide gel as an adjuvant. Cytokines and lymphocytes from serum and spleen were analyzed by enzyme-linked immunosorbent assay, enzyme-linked immunospot assay, and flow cytometry. Results: The VLPs of FMD were purified successfully from yeast protein with a diameter of approximately 25 nm. The immunization of mice showed that animals produced high levels of FMDV antibodies and a higher level of antibodies for a longer time. In addition, higher levels of interferon-γ and CD4+ T cells were observed in mice immunized with VLPs. Conclusions: The expression of VLPs of FMD in H. polymorpha provides a novel strategy for the generation of the FMDV vaccine.

The association of dietary patterns with insulin resistance in Korean adults: based on the 2015 Korea National Health and Nutrition Examination Survey (한국 성인의 식사 패턴과 인슐린 저항성 간의 상관성: 2015년도 국민건강영양조사를 이용하여)

  • Kim, I Seul;Yang, Yoon Jung
    • Journal of Nutrition and Health
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    • v.54 no.3
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    • pp.247-261
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    • 2021
  • Purpose: This study was conducted to identify the association between insulin resistance and the major dietary patterns of Korean adults. Methods: This study used data from the 2015 Korea National Health and Nutrition Examination Survey. The subjects were 2,276 adults aged 19 to 64 years old. Based on the food frequency questionnaire data, 112 food items were reclassified into 30 food groups. The principal component analysis method was applied to identify major dietary patterns. We used homeostatic model assessment of insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI) value as indicators of insulin resistance. The association between major dietary patterns and insulin resistance was investigated using logistic regression analysis. Results: Three major dietary patterns were identified and assigned descriptive names based on the food items with high loadings: 'healthy Korean meal pattern', 'western meal pattern', and 'white rice, alcohol, meat pattern'. As the 'white rice, alcohol, meat pattern' score increased, significant increasing trends for fasting glucose concentration and HOMA-IR and a significant decreasing trend for QUICKI were observed after adjusting for age and sex. The odds ratio of insulin resistance according to the 'healthy Korean meal pattern' and the 'western meal pattern' were not statistically significant. the 'white rice, alcohol, meat pattern' showed a significant positive association with the risk of insulin resistance after adjusting for covariates. Conclusion: These results suggest that the 'white rice, alcohol, meat pattern' is positively associated with the risk of insulin resistance. The white rice, alcohol, meat pattern was related to the high consumption of alcohol together with rice or meat. This pattern was also associated with the high intake of sodium and low intakes of vitamin C, calcium, potassium, and dietary fiber. To confirm the association, further longitudinal studies are required.

Robust Dynamic Projection Mapping onto Deforming Flexible Moving Surface-like Objects (유연한 동적 변형물체에 대한 견고한 다이내믹 프로젝션맵핑)

  • Kim, Hyo-Jung;Park, Jinho
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.7 no.6
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    • pp.897-906
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    • 2017
  • Projection Mapping, also known as Spatial Augmented Reality(SAR) has attracted much attention recently and used for many division, which can augment physical objects with projected various virtual replications. However, conventional approaches towards projection mapping have faced some limitations. Target objects' geometric transformation property does not considered, and movements of flexible objects-like paper are hard to handle, such as folding and bending as natural interaction. Also, precise registration and tracking has been a cumbersome process in the past. While there have been many researches on Projection Mapping on static objects, dynamic projection mapping that can keep tracking of a moving flexible target and aligning the projection at interactive level is still a challenge. Therefore, this paper propose a new method using Unity3D and ARToolkit for high-speed robust tracking and dynamic projection mapping onto non-rigid deforming objects rapidly and interactively. The method consists of four stages, forming cubic bezier surface, process of rendering transformation values, multiple marker recognition and tracking, and webcam real time-lapse imaging. Users can fold, curve, bend and twist to make interaction. This method can achieve three high-quality results. First, the system can detect the strong deformation of objects. Second, it reduces the occlusion error which reduces the misalignment between the target object and the projected video. Lastly, the accuracy and the robustness of this method can make result values to be projected exactly onto the target object in real-time with high-speed and precise transformation tracking.

Comparison of the Science Curricula of Korea, the United States, England, and Singapore: Focus on the Concept of Energy (한국, 미국, 영국, 싱가포르의 과학 교육과정 비교 - 에너지 개념을 중심으로 -)

  • Yoon, Hye-Gyoung;Cheong, Yong Wook
    • Journal of The Korean Association For Science Education
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    • v.37 no.5
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    • pp.799-812
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    • 2017
  • Energy as a powerful and unifying concept to understand natural world has been regarded as one of the key concepts of the science curricula in many countries. However, concerning learning and teaching of energy, various difficulties have been reported widely. This study aimed at analyzing and comparing science curricula of Korea, the U.S., England, and Singapore regarding energy to identify the potential issues for energy curriculum in the future. 2015 revised Korean science curriculum, Next Generation Science Standards of the U.S., Science programmes of study of England, and the Science syllabus of Singapore were compared based on six basic elements of the concept of energy: energy form, energy resource, energy transfer, energy transformation, energy conservation, and energy dissipation. Achievement criteria that include energy were extracted from all curricula and categorized into the six elements. The frequency and distribution of the six elements in the four curricula were compared in terms of school levels and disciplinary areas. Contents of six energy elements were also compared. Though all curricula emphasized energy as a key science concept, we found many differences in the degree of emphasis of basic ideas and specific contents and approaches. Korean curriculum is characterized by 1) high frequency concerning energy form among the elements of the concept of energy, 2) introducing energy forms of unclear meaning, which are not linked with other physical quantities, 3) emphasis on energy conversion in comparison of energy transfer, 4) focusing on mechanical energy conservation instead of more general energy conservation, and 5) absence of the concept of 'system' concerning energy. Issues for energy curriculum development were discussed.

The Study for the Development of Physical Standard and State of Nutrition of a Deaf & Dumb School Boys & Girls (농아학원생(聾啞學院生)의 영양상태(營養狀態)와 체위발달도(體位發達度)에 관(關)한 연구(硏究))

  • Lee, Geum-Yeong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.5 no.1
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    • pp.87-92
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    • 1976
  • Comparing the amount of Hb, the nutriture of the deaf-mutes are better than that of the amentias and the nursery school children. The former, however, shows less condition than that of the boys and girls in the junior physical education school (Hb : 12.7) and the normal family children (Hb : 10.8). In the group of six to eleven years old that is a class a elementary school, the physical condition such as stature, chest circumference, and weight of the deaf -mute is respectively almost the same degree, which is above standard in our country. On the contrary the degree of the amentias and the nursery school children has an inferiority approaching to the standard. In the group of twelve to fifteen years old that is a class of junior high school, the nursery school children have the lowest physical condition and the boys and girls of the physical training school the highest. The order of the growth of physical condition is as follows : Nursery school children

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Proteomic Assessment of the Relevant Factors Affecting Pork Meat Quality Associated with Longissimus dorsi Muscles in Duroc Pigs

  • Cho, Jin Hyoung;Lee, Ra Ham;Jeon, Young-Joo;Park, Seon-Min;Shin, Jae-Cheon;Kim, Seok-Ho;Jeong, Jin Young;Kang, Hyun-sung;Choi, Nag-Jin;Seo, Kang Seok;Cho, Young Sik;Kim, MinSeok S.;Ko, Sungho;Seo, Jae-Min;Lee, Seung-Youp;Shim, Jung-Hyun;Chae, Jung-Il
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.11
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    • pp.1653-1663
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    • 2016
  • Meat quality is a complex trait influenced by many factors, including genetics, nutrition, feeding environment, animal handling, and their interactions. To elucidate relevant factors affecting pork quality associated with oxidative stress and muscle development, we analyzed protein expression in high quality longissimus dorsi muscles (HQLD) and low quality longissimus dorsi muscles (LQLD) from Duroc pigs by liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomic analysis. Between HQLD (n = 20) and LQLD (n = 20) Duroc pigs, 24 differentially expressed proteins were identified by LC-MS/MS. A total of 10 and 14 proteins were highly expressed in HQLD and LQLD, respectively. The 24 proteins have putative functions in the following seven categories: catalytic activity (31%), ATPase activity (19%), oxidoreductase activity (13%), cytoskeletal protein binding (13%), actin binding (12%), calcium ion binding (6%), and structural constituent of muscle (6%). Silver-stained image analysis revealed significant differential expression of lactate dehydrogenase A (LDHA) between HQLD and LQLD Duroc pigs. LDHA was subjected to in vitro study of myogenesis under oxidative stress conditions and LDH activity assay to verification its role in oxidative stress. No significant difference of mRNA expression level of LDHA was found between normal and oxidative stress condition. However, LDH activity was significantly higher under oxidative stress condition than at normal condition using in vitro model of myogenesis. The highly expressed LDHA was positively correlated with LQLD. Moreover, LDHA activity increased by oxidative stress was reduced by antioxidant resveratrol. This paper emphasizes the importance of differential expression patterns of proteins and their interaction for the development of meat quality traits. Our proteome data provides valuable information on important factors which might aid in the regulation of muscle development and the improvement of meat quality in longissimus dorsi muscles of Duroc pigs under oxidative stress conditions.

The Pattern of Natural Regeneration by Canopy Gap Size in the Mixed Broadleaved-Korean Pine Forest of Xiaoxing'an Mountains, China

  • Jin, Guangze;Tian, Yueying;Zhao, Fengxia;Kim, Ji Hong
    • Journal of Korean Society of Forest Science
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    • v.96 no.2
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    • pp.227-234
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    • 2007
  • The forest canopy gap has been well known as a substantial process of forest cyclic regeneration and important role in stand structure, dynamics, and biodiversity of the forest ecosystem. Based on 3,600 $5m{\times}5m$ square grids in a 9ha permanent experimental plot, the study was conducted to evaluate the regeneration pattern of woody species by developmental stage {seedlings (<1 m of height), saplingI (>1 m of height, <2 cm of DBH), and saplingII (2 cm$<200m^2$), $201-400m^2$, $400-600m^2$, $601-800m^2$, and $>800m^2$) in the mixed broadleaved-Korean pine forest. The results indicated that the regenerating trees of Populus ussuriensis occurred only in the canopy gap area, considered to be a typical gap-dependent species. The regeneration of Ulmus japonica, Ulmus laciniata, and Maackia amurensis could be generally satisfied with the gap size of $201-600m^2$, Betula costata and Prunus padus with gap size of $401-800m^2$, Picea koraiensis with gap size of $201-800m^2$, Fraxinus mandshurica and Syringa reticulata var. mandshurica with smaller than $800m^2$, respectively. Acer ukurunduense and Acer tegmentosum were likely to have no problem with the gap size to make gap regeneration. Acer mono and Tilia amurensis looked more capable of regenerating in the closed canopy disregarding the upper crown condition. The regeneration of Pinus koraiensis and Abies nephrolepis had no trouble under the canopy condition in less than $800m^2$of gap size. The density of regenerating shrubs was rather high, especially under the closed canopy, considered to be associated with great amount of regeneration production in such shade tolerant species as Lonicera maackii, Corylus mandshurica, Euonymus pauciflorus, and Philadelphus schrenkii under the closed canopy. Pearson correlation coefficient was computed to compare the similarity among non-gap area and five gap size classes by developmental stages for trees and shrubs. The similarity coefficients among closed canopy and the gap size classes were mostly significantly correlated to each other with a few exceptions.

Anti-inflammatory and Antioxidant Activity of Pomegranate Leaf Extract (석류 잎 추출물의 항염 및 항산화 활성)

  • Yu-Jeong Choi;Jeong-Wook Jo;Hyung-Joo Kim
    • Journal of the Korean Applied Science and Technology
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    • v.41 no.3
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    • pp.613-622
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    • 2024
  • This study aims to evaluate the antioxidant and anti-inflammatory effects of pomegranate (Punica granatum) leaves and to explore the potential of pomegranate leaf extract as an anti-aging cosmetic ingredient. The ethyl acetate fraction of ethanolic extract of pomegranate leaf (EFP) was assessed for its total polyphenol and flavonoid contents, as well as its antioxidant and anti-inflammatory activities. The beneficial components and skin improvement potential of pomegranate leaves were investigated. The results showed that the total polyphenol content of EFP was 871.6±16.3 mg gallic acid/g, and the flavonoid content was 36.6±0.3 mg quercetin/g. In the ABTS radical scavenging assay, EFP exhibited a dose-dependent antioxidant activity with an EC50 value of 24.62±0.48 ㎍/mL. In the skin cell cytotoxicity assay, EFP demonstrated high cell viability at concentrations below 50 ㎍/mL, indicating minimal cytotoxicity. In the nitric oxide (NO) production inhibition assay, EFP effectively inhibited NO production even at low concentrations, with near-complete inhibition at 6 ㎍/mL. These results suggest that EFP has the potential to be utilized as a natural cosmetic ingredient with antioxidant and anti-inflammatory properties.