• Title/Summary/Keyword: material heterogeneity

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Flavonoids from the arial parts of Artemisia agryi and their antioxidant capacity through GSH recovery effect (황해쑥(Artemisia agryi)으로부터 flavonoid 화합물들의 분리 동정과 세포 내 GSH 회복능을 통한 항산화 활성 평가)

  • Hyeon Seon Na;Dahye Yoon;Hyeong-Ju Jeon;Dae Young Lee;Hyoung-Geun Kim
    • Journal of Applied Biological Chemistry
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    • v.65 no.4
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    • pp.247-252
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    • 2022
  • The arial parts of Artemisia argyi were extracted with methanol : water (70:30), and the concentrates was partitioned into EtOAc (ethyl acetate), n-BuOH (normal butanol), and H2O (water) fractions. The repeated silica gel and ODS (octadecyl silica gel) column chromatographies for EtOAc and n-BuOH fractions led to isolation of four flavonoids without any ambiguity based on intensive interpretation of several spectroscopic data including nuclear magnetic resonance, and mass spectrometry. The chemical structure of the isolated compounds revealed to (2S)-naringenin (1), 3-methylkaempferol (2), 3,3'-dimethylquercetin (3), and 3,3',4'-trimethylquercetin (4). These four compounds were first isolated from A. argyi through this study. In this study, four compounds isolated from A. argyi showed an increase in glutathione mean and a decrease in glutathione heterogeneity so that the compounds uniformly raised the intracellular glutathione (GSH) level. Based on these results, it is considered that it can be used as a functional pharmacological material.

Evaluation of the Secondary Particle Effect in Inhomogeneous Media for Proton Therapy Using Geant4 Based MC Simulation (Geant4 몬테칼로 시뮬레이션을 활용한 불균질 매질에서의 양성자의 이차입자 영향 분석)

  • Park, So-Hyun;Jung, Won-Gyun;Rah, Jeong-Eun;Park, Sung-Yong;Suh, Tae-Suk
    • Progress in Medical Physics
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    • v.21 no.4
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    • pp.311-322
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    • 2010
  • In proton therapy, the analysis of secondary particles is important due to delivered dose outside the target volume and thus increased potential risk for the development of secondary cancer. The purpose of this study is to analyze the influence of secondary particles from proton beams on fluence and energy deposition in the presence of inhomogeneous material by using Geant4 simulation toolkit. The inhomogeneity was modeled with the condition that the adipose tissue, bone and lung equivalent slab with thickness of 2 cm were inserted at 30% (Plateau region) and 80% (Bragg peak region) dose points of maximum dose in Bragg curve. The energy of proton was varied with 100, 130, 160 and 190 MeV for energy dependency. The results for secondary particles were presented for the fluence and deposited energy of secondary particles at inhomogeneous condition. Our study demonstrates that the fluence of secondary particles is neither influenced insertion of inhomogeneties nor the energy of initial proton, while there is a little effect by material density. The deposited energy of secondary particles has a difference in the position placed inhomogeneous materials. In the Plateau region, deposited energy of secondary particles mostly depends on the density of inserted materials. Deposited energy in the Bragg region, in otherwise, is influenced by both density of inserted material and initial energy of proton beams. Our results suggest a possibility of prediction about the distribution of secondary particles within complex heterogeneity.

Prognostic Factors of Prostate Cancer in Tunisian Men: Immunohistochemical Study

  • Missaoui, Nabiha;Abdelkarim, Soumaya Ben;Mokni, Moncef;Hmissa, Sihem
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.5
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    • pp.2655-2660
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    • 2016
  • Background: Prostate cancer is the second most common male cancer and remains a leading cause of cancer death worldwide. Heterogeneity regarding recurrence, tumor progression and therapeutic response reflects the inadequacy of traditional prognostic factors and underlies interest in new genetic and molecular markers. In this work, we studied the prognostic value of the expression of 9 proteins, Ki-67, p53, Bcl-2, PSA, HER2, E-cadherin, $p21^{WAF1/Cip1}$, $p27^{Kip1}$ and $p16^{ink4a}$ in prostate cancer. Materials and Methods: We conducted a retrospective study of 50 prostate cancers diagnosed in Pathology Department of Farhet Hached Hospital, Sousse, Tunisia, during a period of 12 months. Clinico-pathological data and survival were investigated. Protein expression was analyzed by immunohistochemistry on archived material. Results: Expression or over-expression of Ki-67, p53, Bcl-2, PSA, HER2, E-Cadherin, $p21^{WAF1/Cip1}$, $p27^{Kip1}$ and $p16^{ink4a}$ was observed in 68%, 24%, 32%, 78%, 12%, 90%, 20%, 44% and 56% of cases, respectively. Overall five-year survival was 68%. A statistically significant correlation was observed between death occurrence and advanced age (p=0.018), degree of tumor differentiation (p=0.0001), perineural invasion (p=0.016) and metastasis occurrence (p=0.05). Death occurrence was significantly correlated with the expression of p53 (p=0.007), Bcl-2 (p=0.02), Ki-67 (p=0.05) and $p27^{Kip1}$ (p=0.04). Conclusions: The p53, Bcl-2, Ki-67 and $p27^{Kip1}$ proteins may be useful additional prognostic markers for prostate cancer. The use of these proteins in clinical practice can improve prognosis prediction, disease screening and treatment response of prostatic cancer.

Quantification of Total Mercury in Antarctic Surface Snow using ICP-SF-MS: Spatial Variation from the Coast to Dome Fuji

  • Han, Yeong-Cheol;Huh, Young-Sook;Hong, Sung-Min;Hur, Soon-Do;Motoyama, Hideaki;Fujita, Shuji;Nakazawa, Fumio;Fukui, Kotaro
    • Bulletin of the Korean Chemical Society
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    • v.32 no.12
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    • pp.4258-4264
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    • 2011
  • The total mercury concentration ($Hg_T$) of surface snow samples collected along a ~1500 km transect in east Queen Maud Land was determined using inductively coupled plasma sector field mass spectrometry to address the behavior of Hg on the Antarctic Plateau. Due to the volatile nature of mercury, measures were taken against Hg loss from standard solutions by choosing appropriate container material and stabilizing agents. Glass bottles with Teflon-lined caps were superior to Teflon and polyethylene containers in protecting against Hg loss, but addition of gold chloride ($AuCl_3$) or bromine chloride (BrCl) was necessary to ensure preservation of Hg. As Hg loss was also observed in snowmelt samples, our analysis may underestimate the actual amount of HgT in the snow. Even so, the measured HgT was still very low (< 0.4-10.8 pg $g^{-1}$, n = 44) without a signal of depositional enhancement accompanying photo-oxidation of atmospheric elemental mercury in austral midsummer. Moreover, the dynamic variation along the traverse implies spatial and temporal heterogeneity in its source processes.

A Study on the Development of the Rock Blastability Classification and the Methods for Minimizing Overbereak in Tunnel (터널 굴착면 여굴 최소화를 위한 발파암 분류(안) 및 공법 개발 연구)

  • 이태노;김동현;서영화
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.303-310
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    • 2002
  • Overbreak occurred inevitably in a tunnel excavation, Is the main factor for increasing cost and time in tunnel projects. Furthermore the damage to the remained rock mass related to the overbreak can give rise to a serious safety problem in tunnels. As a rule of thumb, causes for the overbreak are inaccuracy in drilling, the wrong design of blasting and selection of explosives, and heterogeneity in rock mass. Specially, the geological features of the rock mass around periphery of an excavation are very important factors, so a lot of researches have been conducted to describe these phenomena. But the quantitative geological classification of the rock mass for the overbreak and the method for decreasing the amount of the overbreak have not been established. Besides, the technical improvement of the charge method is requested as explosives for the smooth blasting have not functioned efficiently. In this study, the working face around periphery of an excavation has been continuously sectionalized to 5∼6 parts, and the new Blastability Index for the overbreak based on 6 factors of RMD(Rock Mass Description), UCS(Uniaxial Compressive Strength) JPS(Joint Plane Spacing), JPO(Joint Plane Orientation), JPA(Joint Plane Aperture) and FM(Filling Material) is proposed to classify sections of the working face. On the basis of this classification, the distance between contour holes and the charging density are determined to minimize the overbreak. For controlling the charging density and improving the function of explosives, the New Deck Charge(N.D.C) method utilizing the deck charge method and detonation transmission in hole has been developed.

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Banana agriculture waste as eco-friendly material in fibre-reinforced concrete: An experimental study

  • Mohammed M., Attia;Abd Al-Kader A., Al Sayed;Bassam A., Tayeh;Shymaa M.M., Shawky
    • Advances in concrete construction
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    • v.14 no.5
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    • pp.355-368
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    • 2022
  • This paper investigates the impact of length and volume fractions (VFs) of banana fibres (BFs) on the mechanical and physical properties of concrete. The mechanical properties were compressive strength, splitting tensile, flexural strength, and bond stress, while the physical properties were unit weight and absorption. The slump test was used to determine workability. The concrete's behaviour with BFs was studied using scanning electron microscopy. Experimental work of concrete mixtures with BFs of various lengths (12 mm, 25 mm, and 35 mm) and VFs (0%, 0.5%, 1.0%, and 1.5%) were carried out. The samples did not indicate any agglomeration of fibres or heterogeneity during mixing. The addition of BFs to concrete with VFs of up to 1.50% for all fibre lengths have a significant impact on mechanical properties, also the longer fibres performed better than shorter ones at all volume fractions of BFs. The mix10, which contain BFs with VFs 1.5% and length 35 mm, demonstrated the highest mechanical properties. The compressive strength, splitting tensile, flexural strength, and bond stress of the mix10 were 37.71 MPa, 4.27 Mpa, 6.12 MPa, and 6.75 MPa, an increase of 7.37%, 20.96%, 24.13%, and 11.2% over the reference concrete, which was 35.12 MPa, 3.53 MPa, 4.93 MPa, and 6.07 MP, respectively. The absorption is increased for all lengths by increasing the VFs up to 1.5%. Longer fibres have lower absorption, while shorter fibres have higher absorption. The mix8 had the highest absorption of 4.52%, compared to 3.12% for the control mix. Furthermore, the microstructure of concrete was improved through improved bonding between the fibres and the matrix, which resulted in improved mechanical properties of the composite.

A Comparative Study on the Secondary School Mathematics Education of South and North Korea (남북한 중등학교 수학교육의 통합방안 모색)

  • Woo, Jeong-Ho;Park, Moon-Whan
    • Journal of Educational Research in Mathematics
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    • v.12 no.1
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    • pp.49-70
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    • 2002
  • There have recently been increasing exchanges between South and North Korea in many areas of society, involving politics, economics, culture, education. In response to these developments, research activities are more strongly demanded in each of these areas to help prepare for the final unification of the two parts of the nation. In the area of mathematics education, scholars have started to conduct comparative studies of mathematics education in South and North Korea. As a response to the growing demand of the time, in this thesis we compared the secondary mathematics education in South Korea with that in North Korea. To begin with, we examined the background of education, in North Korea, particularly predominant ideological, epistemological and teaching theoretical aspects of education in North Korea. Thereafter, we compared the mathematics curriculum of South Korea with that of North Korea. On the basis of these examinations, we compared the secondary school mathematics textbooks of South and North Korea, and we attempted to suggest a guideline for researches preparing for the unification of the mathematics curriculum of South and North Korea. As a communist society, North Korea awards the socialist ideology the supreme rank and treats all school subjects as instrumental tools that are subordinated to the dominant communist ideology. On the other hand, under the socialist ideology North Korea also emphasizes the achievement of the objective of socialist economic development by expanding the production of material wealth. As such, mathematics in North Korea is seen as a tool subject for training skilled technical hands and fostering science and technology, hence promoting the socialist material production and economic development. Hence, the mathematics education of North Korea adopts a so-called "awakening teaching method," and emphasizes the approaches that combine intuition with logical explanation using materials related with the ideology or actual life. These basic viewpoints of North Korea on mathematics education are different from those of South Korea, which emphasize the problem-solving ability and acquisition of academic mathematical knowledge, and which focus on organizing as well as discovering knowledge of learners' own accord. In comparison of the secondary school mathematics textbooks used in South and North Korea, we looked through external forms, contents, quantity of each area of school mathematics, viewpoints of teaching, and term. We have identified similarities in algebra area and differences in geometry area especially in teaching sequence and approaching method. Many differences are also found in mathematical terms. Especially, it is found that North Korea uses mathematical terms in Hangul more actively than South Korea. We examined the specific topics that are treated in both South and North Korea, "outer-center & inner-center of triangle" and "mathematical induction", and identified such differences more concretely. Through this comparison, it was found that the concrete heterogeneity in the textbooks largely derive from the differences in the basic ideological viewpoints between South and North Korea. On the basis of the above findings, we attempted to make some suggestions for the researches preparing for the unification in the area of secondary mathematics education.

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Current Status of X-ray CT Based Non Destructive Characterization of Bentonite as an Engineered Barrier Material (공학적방벽재로서 벤토나이트 거동의 X선 단층촬영 기반 비파괴 특성화 현황)

  • Diaz, Melvin B.;Kim, Joo Yeon;Kim, Kwang Yeom;Lee, Changsoo;Kim, Jin-Seop
    • Tunnel and Underground Space
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    • v.31 no.6
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    • pp.400-414
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    • 2021
  • Under high-level radioactive waste repository conditions, bentonite as an engineered barrier material undergoes thermal, hydrological, mechanical, and chemical processes. We report the applications of X-ray Computed Tomography (CT) imaging technique on the characterization and analysis of bentonite over the past decade to provide a reference of the utilization of this technique and the recent research trends. This overview of the X-ray CT technique applications includes the characterization of the bentonite either in pellets or powder form. X-ray imaging has provided a means to extract grain information at the microscale and identify crack networks responsible for the pellets' heterogeneity. Regarding samples of pellets-powder mixtures under hydration, X-ray CT allowed the identification and monitoring of heterogeneous zones throughout the test. Some results showed how zones with pellets only swell faster compared to others composed of pellets and powder. Moreover, the behavior of fissures between grains and bentonite matrix was observed to change under drying and hydrating conditions, tending to close during the former and open during the latter. The development of specializing software has allowed obtaining strain fields from a sequence of images. In more recent works, X-ray CT technique has served to estimate the dry density, water content, and particle displacement at different testing times. Also, when temperature was added to the hydration process of a sample, CT technology offered a way to observe localized and global density changes over time.

Removal of Cu(II) with the Recycled Hydroxylapatite from Animal Bones (동물뼈로부터 재활용된 hydroxylapatite를 이용한 Cu(II) 제거)

  • Kim, Mu-Nui;Kim, Won-Gee;Lee, Seung-Mok;Yang, Jae-Kyu
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.9
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    • pp.735-742
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    • 2009
  • The bone of spinal animals has a hydroxylapatite ($Ca_{10}(PO_4)_6(OH)_2$, HAp) structure which is well known as an excellent inorganic ion exchanger for various heavy metal ions in solutions. In this study, the reusability of cow-bone, pig-bone and fish-bone as a potential material for the removal of heavy metals in solutions was evaluated from the removal of Cu(II) ion in batch tests. The surface properties of three bones, calcined at different temperatures, were measured with SEM, XRD, FT-IR analyses. From the SEM analysis, a clear development of heterogeneity as well as pores having small diameter was observed as the calcination temperature increased. The results of X-ray diffraction analysis showed well developed crystallinity on the surface of calcined bones obtained at higher temperatures, suggesting a transform of amorphous type to crystalline type. Fourier transform infrared (FT-IR) analysis showed disappearance of water molecule on the surface of HAp and organic functional groups of the HAp with increasing the calcination temperatures. Cu(II) removal in the control test was below 15%. By the way, additional 40% increase of Cu(II) removal was observed in the presence of calcined bones. For three bones, Cu(II) removal was decreased as the calcined temperature increased. Cu(II) removal was increased as the solution pH increased due to a favorable condition for the cation exchange as well as precipitation.

Suitability Examination of Flex sensor and FBG Sensor for Levee Safety Management (제방 안전관리를 위한 Flex센서와 FBG센서의 적용성 검토)

  • Lee, In-Je;Lee, Eun-Tae;Kang, Jeong-Hoon;Kim, Dong-Min;Chang, Ki-Tae
    • Journal of Korea Water Resources Association
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    • v.41 no.11
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    • pp.1135-1142
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    • 2008
  • Collapse of the levee surrounding structure(culvert) accounts for l0 % of collapse factors of the river levees. In particular, in 2002, the levee collapse that happened at "Nakdong River" at flood usually happened around culverts. This levee collapse has mechanism that the cavity expands with internal erosion at flood after the pore and cavity are formed between culvert and levee copula which are heterogeneity material. The study regarding the cavity or flowing detection around a culvert for safety management of a river levee is in the proceeding. In this study, the characteristic of two sensors could be figured out through an experiment about displacement measure of Flex sensor and FBG sensor and the decision of more suitable sensor was possible for safety supervision of river levee. According to an experiment result, several characteristics of FBG sensor could be known in consistency of the measure data and minute displacement measure part regarding displacement measure and this characteristic may supplement a shortcoming of Flex sensor at this time.