• Title/Summary/Keyword: 강도 감소인자

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Chemo-Mechanical Analysis of Bifunctional Linear DGEBA/Linear Amine (DDM, DDS) Resin Casting Systems (DGEBA/방향족 아민(DDM, DDS) 경화제의 벤젠링 사이의 관능기 변화가 물성 변화에 미치는 영향에 대한 연구)

  • 명인호;정인재;이재락
    • Composites Research
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    • v.12 no.4
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    • pp.71-78
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    • 1999
  • To determine the effect of chemical structure of linear amine curing agents on thermal and mechanical properties, standard epoxy resin DGEBA was cured with diaminodiphenyl methane (DDM), diaminodiphenyl sulphone (DDS) in a stoichiometrically equivalent ratio. From this work, the effect of aromatic amine curing agents. In contrast, the results show that the DGEBA/DDS cure system having the sulfone structure between the benzene rings had higher values in the conversion of epoxide, density, shrinkage (%), glass transition temperature, tensile modulus and strength, flexural modulus and strength than the DGEBA/DDM cure system having methylene structure between the benzene rings, whereas the DGEBA/DDM cure system presented higher values in the maximum exothermic temperature, thermal expansion coefficient, and thermal stability. These results are caused by the relative effects of sulfone group having strong electronegativity and methylene group having (+) repulsive property and stem from the effect of the conversion ratio of epoxide group. The result of fractography shows that the each grain size of the DDM/DGEBA system with feather-like structure is larger than that of the DDS/DGEBA system.

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Effects of a Combined Diet of Jerusalem Artichoke's Inulin, Lotus Leaf and Herb Extracts in Obesity-induced White Rat with Fat Diet (돼지감자의 이눌린, 연잎, 허브의 병합식이가 고지방식이로 유도된 비만흰쥐에 미치는 영향)

  • Lee, Eun-Hye;Lee, Ye-Jin;Choi, Ok-Byung;Kang, Sang-Mo
    • Applied Biological Chemistry
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    • v.50 no.4
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    • pp.295-303
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    • 2007
  • A preliminary diet experiment utilizing Jerusalem artichoke's inulin, lotus leaf powder, nettle powder and eucalyptus powder extract indicated that combining all four elements gave the most effective result. Therefore, a study was conducted to evaluate the effectiveness of combined diet for weight loss. In this study, Sprague-Dawley, male white rats about 200 g in weight was fed with high fat diet for 8 weeks in order to induce obesity followed by 4 week administration of combined diet to look into the effect of the diet. After a total of 12 weeks of feeding, factors relevant to weight, blood, and lipid metabolism by liver in the body were researched and histologic change was examined with optical microscope. In terms of weight change, both high fat diet group and regular diet group gained weight from high fat diet for 8 weeks compared to normal group. Then, for another 4 weeks, while normal group and high fat diet group kept gaining weight, combined diet group which was provided with high fat diet for 8 weeks, lost weight to the normal group level after 3 week administration of diet. However, after the 4th week of administration, the group weighted significantly less than the normal group and the efficiency of diet also significantly dropped. In the biochemical analysis of blood, total cholesterol, LDL-cholesterol, triglyceride, glucose, GOT, GPT, ${\gamma}-GTP$ and creatine showed significant increase in high fat diet group and there was no significant difference between diet group and normal group except for GPT, ${\gamma}-GTP$ and creatine. In the biochemical analysis of liver, there was significant increase in LDL-cholesterol, triglyceride of high fat diet group compared to normal group, while there was no significant difference in term of total cholesterol and HDL-cholesterol. Compared to normal group, diet group had higher HDL-cholesterol, while total cholesterol dropped significantly. There was no significant difference in terms of LDL-cholesterol and triglyceride. Besides, in high fat diet group, observation of histologic change in liver and change in ultrastructure showed volume increase of hepatic cell and severe fatty degeneration in hepatic cell around hepatic vein. However in diet group, like normal group, no pathological change was observed in terms of cytoplasm, nucleus and capillary in hepatocyte and the alignment of hepatocyte had regularity thanks to the administration of combined diet. Therefore, combined diet utilizing Jerusalem artichoke's inulin, lotus leaf powder, nettle powder and eucalyptus powder was proven to be an effective measure to prevent and improve obesity as a result of abnormal adipose deposition.

Study on Role of Platelet Aggregation in Cerebrovascular Disease (뇌졸중증(腦卒中症)에 있어서 혈소판(血少板) 응집( 凝集)의 역할에 관한 연구(硏究))

  • Hong, Ki-Whan;Lee, Won-Suk
    • The Korean Journal of Pharmacology
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    • v.18 no.2
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    • pp.15-25
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    • 1982
  • It was undertake to investigate the factors involved in the micro thrombus formation in the plasma from the patients with cerebrovascular disease(CVD) and the in vitro actions of sodium nitroprusside on the platelet aggregate formation. 1) The microthrombus formation in the plasma from CVD was significantly enhanced, in comparison with that from the healthy volunteers. 2) Both lipid peroxide and cathepsin D in the plasma from CVD were higher than those levels from the healthy volunteers. 3) Whereas the platelets from healthy individuals showed less aggregation activity in response to ADP in the second phase those from CVD revealed the enhanced aggregating response to ADP. 4) When the bovine basilar artery, rabbit aorta and human umbilical artery were pretreated with $K^+-free$ PSS, ouabain, 13-hydroperoxylinoleic acid(13-HPLA) and cadmium they markedly enhanced the platelet aggregability respectively. 5) Platelet aggregation induced by $K^+-free$ PSS-treated bovine basilar artery was decreased by sodium nitroprusside in a dose-dependent manner, but not by either hydralazine. 6) Both dibutyryl cyclic AMP and 8-bromo cyclic GMP had the inhibitory action on the platelet aggregation. However, the latter had more prominent action than former. The antiaggregating effect by sodium nitroprusside was antagonized by pretreatment with methylene blue, but not by hemoglobin. These results provide the evidences for the therapeutic use of sodium nitroprusside in the emergency of cerebrovascular disease and in remains the further study of the clinical therapy with it.

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Mania Construction and Constitution based on Animation 'Full metal Alchemist's Character (애니메이션 '강철의 연금술사' 의 캐릭터를 중심으로 한 매니아 형성과 구조)

  • Park, Yoon-Sung;Kim, Hye-Sung;Lee, Ga-Young
    • The Journal of the Korea Contents Association
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    • v.6 no.12
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    • pp.253-260
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    • 2006
  • As media and product became variety, the propensity of the people is be coming various. From diversity, there we could search for some popularity is called 'the mania.' When Mania takes shape, the product will being longer even masses in these days only have short-term life. Also there are hundreds of animations that has short-term life whom people forgot everyday they watch. However, the animations could lasting its value which has the Mania. This thesis is a studies on the constitution of Mania from animation 'Fullmetal Alchemist's Character The BONES had made. We can learn that the audience were not just like the animation, but get crazy for it by comparing Japanese animation industry in those days; before it has been shrinking and manufacturing various contents from Fullmetal Alchemist means there is enough consumtions. There are many reasons to form Mania group, but specially the character symbols at the works as a whole. From this study is to know a cause of how the animation 'Fullmetal Alchemist' made huge Mania group, and significance value of the work those group left.

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[ $Ca^{2+}\;and\;K^+$ ] Concentrations Change during Early Embryonic Development in Mouse (생쥐 초기 배 발달 동안 변화되는 칼슘과 포타슘 이온)

  • Kang D.W.;Hur C.G.;Choi C.R.;Park J.Y.;Hong S.G.;Han J.H.
    • Journal of Embryo Transfer
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    • v.21 no.1
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    • pp.35-43
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    • 2006
  • Ions play important roles in various cellular processes including fertilization and differentiation. However, it is little known whether how ions are regulated during early embryonic development in mammalian animals. In this study, we examined changes in $Ca^{2+}\;and\;K^+$ concentrations in embryos and oviduct during mouse early embryonic development using patch clamp technique and confocal laser scanning microscopy. The intracellular calcium concentration in each stage embryos did not markedly change. At 56h afier hCG injection when 8-cell embryos could be Isolated from oviduct, $K^+$ concentration in oviduct increased by 26% compared with that at 14h after injection of hCG During early embryonic development, membrane potential was depolarized (from -38 mV to -16 mV), and $Ca^{2+}$ currents decreased, indicating that some $K^+$ channel might control membrane potential in oocytes. To record the changes in membrane potential induced by influx of $Ca^{2+}$ in mouse oocytes, we applied 5 mM $Ca^{2+}$ to the bath solution. The membrane potential transiently hyperpolarized and then recovered. In order to classify $K^+$ channels that cause hyperpolarization, we first applied TEA and apamin, general $K^+$ channel blockers, to the bath solution. Interestingly, the hyperpolarization of membrane potential still appeared in oocytes pretreated with TEA and apamin. This result suggest that the $K^+$ channel that induces hyperpolarization could belong to another $K^+$ channel such as two-pore domain $K^+(K_{2P})$channel that a.e insensitive to TEA and apamin. From these results, we suggest that the changes in $Ca^{2+}\;and\;K^+$ concentrations play a critical role in cell proliferation, differentiation and reproduction as well as early embryonic development, and $K_{2P}$ channels could be involved in regulation of membrane potential in ovulated oocytes.

Phosphorus Phases in the Surface Sediment of the South Sea (남해 표층 퇴적물에서의 인의 존재상)

  • SON Jaekyung;LEE Tongsup;YANG Han Soeb
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.32 no.5
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    • pp.680-687
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    • 1999
  • To understand the role of shelf sediment in phosphorus biogeochemical cycle, we carried out sequential sediment extraction (SEDEX) of P and porewater analysis on 14 core samples collected in the South Sea of Korea, SEDEX classified P-pools into 5 phases and results are grouped into two categories: reactive P (loosely sorbed-P and Fe bound-P) and refractory P (detrital inorganic-p, authigenic mineral-P and organic-P). Total P concentrations are decreased with sediment depth in all samples as a result of dissolution to porewater. Reactive P comprises about $20\~50\%$ of total P, and iron bound-P is the major form consisting $70\~80\%$ of reactive P-pool. Iron bound-P decreases sharply with depth. Depth profiles of dissolved P concentration in porewater show mirror image of iron bound-P, revealing the role of FeOOH as a regulator of reactive P supply to overlying water column. Authigenic mineral-P consists less than $5\%$ of total P, thus removal of reactive P by converting into refractory P seems inefficient in shelf sediment. This implies that continental shelf sediment sequesters P temporarily rather than permanently. Results show local variation. Nakdong estuary receiving large amount of terrigenous input shows the highest concentration of total P and reactive P. Here iron oxyhydroxides at the surface sediment control the water column flux of P from sediment. Although total P content at the surface is comparable (500$\~$600 ${\mu}g{\cdot}g^{-1}$) between the South Sea and East China Sea, the former contains more iron bound-P and less derital inorganic-P than the latter. Reasons for the difference seem due in part to particle texture, and to biological productivity which depends roughly on the distance from land.

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Effects of Light, Temperature, and Water Stress on the Photosynthesis and Respiration Rates of Leaves in Four Oak Species (4종(種)의 참나무엽(葉)의 광합성속도(光合成速度)와 호흡속도(呼吸速度)에 미치는 광(光), 온도(溫度), 수분(水分)의 영향(影響))

  • Han, Sang Sup;Kim, Ha Sun
    • Journal of Korean Society of Forest Science
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    • v.78 no.2
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    • pp.151-159
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    • 1989
  • The present study has been designed to define the effects of photosynthetically active radiation, leaf temperature, and water stress on photosynthesis and respiration of leaves of four oak species (Quercus mongolica, Quercus aliens, Quercus variabilis, and Quercus serrate). The results obtained are as follows : 1. The estimated light compensation points at which Pn approached zero were 38, 24, 20, and $18{\mu}Em^{-2}s^{-1}$ for Q. aliens, Q. variabilis, Q, mongolica, and Q. serrate, respectively. The light saturation points occurred at $500{\mu}Em^{-2}s^{-1}$ in three oak species except Q, aliens. 2. The maximum rates of Pn were 19.7, 15.2, 11.2, and 11.0 mg $CO_2$ $dm^{-2}h^{-1}$ for Q. variabilis, Q. serrate, Q. monglica, and Q. aliens leaves, respectively. 3. The transpiration rates of Q. variabilis and Q. serrate leaves were slightly higher than those of Q. mongolica and Q. aliens leaves at various photosynthetically active radiations(PAR), but cuticular transpiration rates at dark were similar in four oak species. 4. The optimum photosynthesis occurred at $25^{\circ}C$ in Q. aliens, Q. variabilis, and Q. serrate leaves, but $20^{\circ}C$ in Q. mongolica leaves. In four oak species, the net photosynthesis approached zero at about $40^{\circ}C$. 5. The dark respiration rates of leaves exhibited the following ranking of species : Q, variabilis > Q. mongolica > Q. aliens > Q. serrate. 6. The maximum productive efficiency (Pg/Rd) of leaves occurred highest in Q, serrate at $20^{\circ}C$, then in Q. mongolica at $20^{\circ}C$, then in Q, aliens at $25^{\circ}C$, and finally in Q. variabilis at $15^{\circ}C$. 7. The decrease of net photosynthesis in Q. serrate began at about -1.2 MPa, and then approached zero at -2.9 MPa of leaf water potential. The decrease of net photosynthesis began at 3% of water loss, and then approached zero at 17.5% of water loss. 8. As indicated by tissue-water relations parameters, it may be suggested that Q. aliens and Q. variabilis are more tolerant and favored on xeric forest soils than Q. mongolica and Q. serrate.

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A Study on the Characteristics of the Atmospheric Environment in Suwon Based on GIS Data and Measured Meteorological Data and Fine Particle Concentrations (GIS 자료와 지상측정 기상·미세먼지 자료에 기반한 수원시 지역의 도시대기환경 특성 연구)

  • Wang, Jang-Woon;Han, Sang-Cheol;Mun, Da-Som;Yang, Minjune;Choi, Seok-Hwan;Kang, Eunha;Kim, Jae-Jin
    • Korean Journal of Remote Sensing
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    • v.37 no.6_2
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    • pp.1849-1858
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    • 2021
  • We analyzed the monthly and annual trends of the meteorological factors(wind speeds and directions and air temperatures) measured at an automated synoptic observation system (ASOS) and fine particle (PM10 and PM2.5) concentrations measured at the air quality monitoring systems(AQMSs) in Suwon. In addition, we investigated how the fine particle concentrations were related to the meteorological factors as well as urban morphological parameters (fractions of building volume and road area). We calculated the total volume of buildings and the total area of the roads in the area of 2 km × 2 km centered at each AQMS using the geographic information system and environmental geographic information system. The analysis of the meteorological factors showed that the dominant wind directions at the ASOS were westerly and northwesterly and that the average wind speed was strong in Spring. The measured fine particle concentrations were low in Summer and early Autumn (July to September) and high in Spring and Winter. In 2020, the annual mean fine particle concentration was lowest at most AQMSs. The fine particle concentrations were negatively and weakly correlated with the measured wind speeds and air temperatures (the correlation between PM2.5 concentrations and air temperatures was relatively strong). In Suwon city, at least for 6 AQMSs except for the RAQMS 131116 and AQMS 131118, the PM10 concentrations were affected mainly by the transport from outside rather than primary emission from mobile sources or wind speed decrease caused by buildings and, in the case of PM2.5, vise versa.

Results of Radiation Therapy for Carcinoma of the Uterine Cervix (자궁경부암의 방사선치료 성적)

  • Lee Kyung-Ja
    • Radiation Oncology Journal
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    • v.13 no.4
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    • pp.359-368
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    • 1995
  • Purpose : This is a retrospective analysis for pattern of failure, survival rate and prognostic factors of 114 patients with histologically proven invasive cancer of the uterine cervix treated with definitive irradiation. Materials and Methods : One hundred fourteen patients with invasive carcinoma of the cervix were treated with a combination of intracavitary irradiation using Fletcher-Suit applicator and external beam irradiation by 6MV X-ray at the Ewha Womans University Hospital between March 1982 and Mar 1990. The median age was 53 years(range:30-77 years). FIGO stage distribution was 19 for IB, 23 for IIA, 42 for IIB, 12 for IIIA and 18 for IIIB. Summation dose of external beam and intracavitary irradiation to point A was 80-90 Gy(median:8580 cGy) in early stage(IB-IIA) and 85-100 Gy(median:8850 cGy) in advanced stage(IIB-IIIB). Kaplan-Meier method was used to estimate the survival rate and multivariate analysis for progrostic factors was performed using the Log likelihood for Weibull Results : The pelvic failure rates by stage were $10.5{\%}$ for IB. $8.7{\%}$ for IIA, $23.8{\%}$ for IIB, $50.0{\%}$ for IIIA and $38.9{\%}$ for IIIB. The rate of distant metastasis by stage were $0{\%}$ for IB, $8.7{\%}$ for IIA, $4.8{\%}$ for IIB. $0{\%}$ for IIIA and $11.1{\%}$ for IIIB. The time of failure was from 3 to 50 months and with median of 15 months after completion of radiation therapy. There was no significant coorelation between dose to point A($\leq$90 Gy vs >90 Gy) and pelvic tumor control(P>0.05). Incidence rates of grade 2 rectal and bladder complications were $3.5{\%}$(4/114) and $7{\%}$(8/114), respectively and 1 patient had sigmoid colon obstruction and 1 patient had severe cystitis. Overall 5-year survival rate was $70.5{\%}$ and disease-free survival rate was $53.6{\%}$. Overall 5-year survival rate by stage was $100{\%}$ for IB, $76.9{\%}$ for IIA, $77.6{\%}$ for IIB $87.5{\%}$ for IIIA and $69.1{\%}$ for IIIB. Five-rear disease-free survival rate by stage was $81.3{\%}$ for IB, $67.9{\%}$ for IIA, $46.8{\%}$ for IIB, $45.4{\%}$ for IIIA and $34.4{\%}$ for IIIB. The prognostic factors for disease-free survival rate by multivariate analysis was performance status(p= 0.0063) and response rate after completion of radiation therapy(p= 0.0026) but stage, age and radiation dose to point A were not siginificant. Conclusion : The result of radiation therapy for early stage of the uterine cervix cancer was relatively good but local control rate and survival rate in advanced stage were poor inspite of high dose irradiation to point A above 90 Gy. Prospective randomized studies are recommended to establish optimal tumor doses for various stages and volume of carcinoma of uterine cervix, And ajuvant chemotherapy or radiation-sensitizing agents must be considered to increase the pelvic control and survival rate in advanced cancer of uterine cervix.

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Effects of PGA-LM on CD4+CD25+foxp3+ Treg Cell Activation in Isolated CD4+ T Cells in NC/Nga Mice (NC/Nga 생쥐에서 분리한 T 세포에서 foxp3+ 세포 활성화에 대한 PGA-LM의 효과)

  • Jang, Soon-Nam;Kim, Kum-Lan;Kang, Sang-Mo
    • Microbiology and Biotechnology Letters
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    • v.37 no.2
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    • pp.160-169
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    • 2009
  • Poly-$\gamma$-glutamic acid ($\gamma$-PGA) was mixed natural flora of Bacillus subtilis, contaminated from cooked soybeans. Also, it was performed to find out the antiallergic activity by using NC/Nga mice, in vitro. The $\gamma$-PGA (PGA-HM : PGA-high molecular weight), Molecular weight 300 kDa, was decomposed and made PGA-LM (PGA-low molecular weight) which has molecular weight below 30 kDa by sonication. Therefore, it was same result between PGA-HM and PGA-LM, and reported PGA-LM as basic result. We found that PGA-LM contains antiallergic efficacy that inhibit B cells and Th2 cells activation from isolated CD4+T cells in NC/Nga atopic dermatitis model mice, and not show a cytotoxicity in the hFCs. To investigate the effects of these PGA-LM in vitro, isolation of splenic B cell and CD4+ T cells in atopic dermatitis mice were used. To elucidate the role of PGA-LM in anti-CD40+ interleukin-4 (IL-4)-mediated B-cell activation, showed that the capacity of B cells to expression IL-$1\beta$, IL-6, and TNF-$\alpha$ mRNA down-regulated, and IL-10 mRNA up-regulation by PGA-LM treatment, but it had no effect on TGF-$\beta$ expression. In addition to CD4+IFN-$\gamma$+ and CD4+CD25+foxp3+, the functions of PGA-LM in the development of the CD4+CD25+foxp3+ and CD4+IFN-$\gamma$+cells, the phenotype and functions of PGA-LM induced CD4+CD25+foxp3+, and CD4+IFN-$\gamma$+cells in CD4+T cells. These results suggested that PGA-LM could change cytokine production and generate CD4+CD25+foxp3+ Tregs in NC/Nga mice, and may be effective for immunotherapy in patients with AD.