• 제목/요약/키워드: Permeability materials

검색결과 1,073건 처리시간 0.023초

Role of +405C>G and +936C>T Polymorphisms of the Vascular Endothelial Growth Factor Gene and Risk of Esophageal Cancer in the Kashmiri Population

  • Qasim, Iqbal;Bhat, Imtiyaz Ahmad;Masoodi, Khalid Zafar;Shah, Zafar Amin
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권1호
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    • pp.97-101
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    • 2015
  • Background: The gene for the vascular endothelial growth factor (VEGF), which promotes angiogenesis and permeability, is polymorphic. The aim of the present study was to evaluate the relationship between +936C>T and +404C>G polymorphism of VEGF with risk of esophageal cancer in the Kashmiri population in India. Materials and Methods: 150 esophageal cancer patients and 150 unrelated healthy controls were genotyped for two VGEF SNPs (+405C/G, and +936C/T) using DNA extracted from prospectively collected blood samples by the PCR-RFLP method. Results: For the VEGF +936C>T polymorphism a significant association of CT and combined CT+TT genotypes was observed with increased risk of esophageal cancer (p=0.021; 0.024). For the +405C>G polymorphism we observed significantly increased frequency of GG genotype in cases as compared to controls and also the +405 GG Genotype was observed to have a two fold risk(OR=2.7356; 95%CI=1.1409-6.5593; p=0.020). The combined genotypes of GG-CC and GG-CT of +405C>G and +936C>T were found to be significantly associated with increased risk of esophageal cancer (p=0.0376; 0.0099). Conclusions: From the results of the present study a significant association of +936C>T and +405C>G polymorphisms with increased esophageal cancer risk exists in the Kashmiri population.

전차병복 착용실태에 관한 연구 (A Study on the Actual Wearing Conditions of Korean Military Tank Driver's Clothing)

  • 권서윤;임채근;신동우;정현미
    • 한국의류산업학회지
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    • 제13권4호
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    • pp.582-589
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    • 2011
  • The purpose of this study was to investigate problems of design, fitness, suitability for movement, and comfort in current Korean military tank driver's clothing through analysis of actual wearing condition by questionnaire and field evaluation and. to provide basic data for developing a improved design of Korean military tank driver's clothing. The survey was done for 477 military tank driver and the field evaluation was also done for evaluation. The overall satisfaction for design of military tank driver's clothing(3.25) was higher than that for the easiness in wearing and taking off(2.76). The military tank drivers evaluated that current coverall type of clothing is more suitable than two-piece type of clothing. The overall satisfaction for fitness of clothing was as a whole low(2.82~3.09), Especially, the satisfaction for fitness of from front and back rise length was the lowest one. In the satisfaction for clothing materials, the satisfaction for the breathability of material was the lowest, followed by clothing insulation and air permeability. The satisfaction for movement was low in bending waist and raising forward and aside. The part which surveyors think most dissatisfactory was also front and back rise length. The frequency in use of pocket was the highest in chest pocket, followed by waist and pants pockets. The satisfaction for opening easiness of hips opening part was very low(2.64).

Expression Pattern and Prognostic Significance of Claudin 1, 4 and 7 in Pancreatic Cancer

  • Alikanoglu, Arsenal Sezgin;Gunduz, Seyda;Demirpence, Ozlem;Suren, Dinc;Gunduz, Umut Riza;Sezer, Cem;Yildiz, Mustafa;Yildirim, Mustafa
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권10호
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    • pp.4387-4392
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    • 2015
  • Background: Tight junctions (TJs) organise paracellular permeability and they have an important role in epithelial and endothelial cell polarity and permanence of barrier function. It has been demonstrated that the Claudin family constitutes an important component of them. In this study, we assessed expression patterns of of Claudin1, 4 and 7 and whether they have any relation with prognosis in patients with pancreatic cancer. Materials and Methods: Expression patterns of Claudin 1,4 and 7 were examined by immunohistochemistry in 25 patients with a histopathological diagnosis of pancreatic cancer using a semiquantitative scoring of the extent and intensity of staining. After grouping the staining scores as low (final score 0-2) and high (final score 3-9) the relation between expression of Claudin 1,4 and 7 and survival was evaluated. Results: There was no significant relation between expression of Claudin 1,4 and 7 and gender and stage. No statistically significant relation was found between Claudin 1 and 4 expression and survival whereas a statistically significant relation was found between decrease in Claudin 7 expression and decrease in survival. Conclusions: Claudins have important functions other than their popular function known as adhesion. Supporting this hypothesis, we found a statistically significant relationship between increased Claudin 7 expression and increased survival time, and this suggests that Claudin 7 may exert different tumorigenic effects in pancreatic cancer other than its well-known adhesion effect.

서울지역 라돈농도의 분포예측을 위한 공간분석법 연구 (Studies on the Spatial Analysis for Distribution Estimation of Radon Concentration at the Seoul Area)

  • 백승아;이태정;김신도;김동술
    • 한국대기환경학회지
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    • 제24권5호
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    • pp.538-550
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    • 2008
  • Radon is an invisible, odorless, and radioactive gas. It is formed by the disintegration of radium, which is a decay product of uranium. Some amounts of radon gas and its products are present ubiquitously in the soil, water, and air. Particularly high radon levels occur in regions of high uranium content. Although radon is permeable into indoor environment not only through geological features (bed rock and permeability) but also through the construction materials and underground water, the radiation from the geological features is generally main exposure factor. So there can be a problem in a certain space such as the underground and/or relatively poor ventilation condition. In this study, a GIS technique was used in order to investigate spatial distribution of radon measured from sub- way stations of 1 thru 8 in Seoul, Korea in 1991, 1998, 2001, and 2006. Spatial analysis was applied to reproduce the radon distribution. We utilized spatial analysis techniques such as inverse distance weighted averaging (IDW) and kriging techniques which are widely used to relate between different spatial points. To validate the results from the analyses, the jackknife technique for an uncertainty test was performed. When the number of measuring sites was less than 100 and also when the number of omitted sites increased, the kriging technique was better than IDW. On the other hand, when the number of sites was over 100, IDW technique was better than kriging technique. Thus the selection of analytical tool was affected sensitives by the analysis based on the number of measuring sites.

친환경 감물가공 소재의 자외선 조사에 의한 물리적 특성변화에 대한 연구 -견 및 나일론 직물- (Effects of U.V. Irradiation on the Physical Properties of Fabrics Treated with Eco-friendly Persimmon Juice -Silk and Nylon Fabrics-)

  • 김지민;김종준
    • 패션비즈니스
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    • 제19권4호
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    • pp.120-134
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    • 2015
  • This study aimed to determine the physical properties of silk and nylon fabrics that are treated with persimmon juice in accordance with irradiation time of ultraviolet spectrum. Persimmon juice dyeing has the advantage of using the tannin component of the persimmon. Tannin plays an important role in inhibiting photodegradation of fibers or polymers. Among fibrous materials, silk and nylon are prone to deterioration by light. Hence, this study aimed to reduce these weaknesses of silk and nylon by applying persimmon juice treatment. We accordingly carried out investigation and experiments on ultraviolet irradiation, and physical characteristics of treated fabrics. The persimmon juice treatment process led to increased weight and thickness. In addition, the air permeability of silk fabric was increased, as compared to the control specimen; whereas, that of nylon fabric was decreased. Both drape stiffness and flex stiffness of silk and nylon tended to be high in textiles processed with persimmon juice treatment, as compared to the control textile. Peak load and elongation at peak load of untreated samples clearly decreased in both silk and nylon fabrics with the increase of ultraviolet irradiation time, while those of persimmon juice treated samples increased. Furthermore, ultraviolet blocking ratio measurement indicated that the fabric specimens treated with persimmon juice blocked U.V. spectrum better than the control specimen.

공항포장 시멘트안정처리기층에 적용하기 위한 투수콘크리트 개발에 관한 기초연구 (Fundamental Study on Pervious Concrete Materials for Airport Pavement Cement Treated Base Course)

  • 김승원;오지현;장봉진;주민관;김인태;박철우
    • 한국도로학회논문집
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    • 제15권4호
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    • pp.65-73
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    • 2013
  • PURPOSES : As a research to develop a cement treated base course for an airport pavement which can enhance its drainage, this paper investigated the strength, infiltration performance and durability of the pervious concrete with respect to maximum coarse aggregate sizes and compaction methods. METHODS : This study measured compressive strength, infiltration rate, continuous porosity and freeze-thaw resistance of pervious concrete specimens, which were fabricated with five different compaction methods and different maximum aggregate sizes. In addition, in order to reduce the usage of Portland cement content and to enhance environment-friendliness, a portion of the cement was replaced with Ground Granulated Blast Furnace Slag (GGBS). RESULTS: Compressive strength requirement, 5 MPa at 7 days, was met for all applied compaction methods and aggregate sizes, except for the case of self-compaction. Infiltration rate became increased as the size of aggregate increased. The measured continuous porosities varied with the different compaction methods but the variation was not significant. When GGBS was incorporated, the strength requirement was successfully satisfied and the resistance to freezing-thawing was also superior to the required limit. CONCLUSIONS: The infiltration rate increased as the maximum size of aggregate increased but considering construct ability and supply of course aggregate, its size is recommended to be 25mm. With the suggested mix proportions, the developed pervious concrete is expected to successfully meet requirements for strength, drainage and durability for cement treated base or subbase course of an airport pavement.

석조문화재 보존처리용 무기질바인더의 성능개선을 위한 조성물 연구 (A Study on the Composition for Improving the Performance of Inorganic Binders for Conservation Treatment of Stone Cultural Heritages)

  • 이태종;조하진;채승아;박희정;강산하
    • 보존과학회지
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    • 제36권5호
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    • pp.339-350
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    • 2020
  • 본 연구는 석조문화재 보존처리용(표면마감) 무기질바인더가 암석에 위해한 영향을 미치는 백화현상을 제어하기 위해 광물기반의 충전제와 발수제를 혼합한 하이브리드 기술을 적용하였다. 연구결과, 무기질바인더 성능개선에 효과적인 충전제(실리카흄 3.4%)와 발수제(실란-실록산 1%)를 선정하였으며, 해당 중량비율은 백화물질 제어에 효과가 있는 것으로 판단된다. 또한 압축강도 기준을(20 MPa) 상회하였고 흡수율은 낮아 투수저항성이 높은 것을 확인하였다. 이온용출 결과도 백화현상에 직·간접적으로 작용하는 이온의 검출량이 대조군보다 작게 검출되어 상대적으로 안정적인 것으로 판단된다.

Protective effects of an ethanol extract of Angelica keiskei against acetaminophen-induced hepatotoxicity in HepG2 and HepaRG cells

  • Choi, Yoon-Hee;Lee, Hyun Sook;Chung, Cha-Kwon;Kim, Eun Ji;Kang, Il-Jun
    • Nutrition Research and Practice
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    • 제11권2호
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    • pp.97-104
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    • 2017
  • BACKGROUND/OBJECTIVE: Although Angelica keiskei (AK) has widely been utilized for the purpose of general health improvement among Asian, its functionality and mechanism of action. The aim of this study was to determine the protective effect of ethanol extract of AK (AK-Ex) on acute hepatotoxicity induced by acetaminophen (AAP) in HepG2 human hepatocellular liver carcinoma cells and HepaRG human hepatic progenitor cells. MATERIALS/METHODS: AK-Ex was prepared HepG2 and HepaRG cells were cultured with various concentrations and 30 mM AAP. The protective effects of AK-Ex against AAP-induced hepatotoxicity in HepG2 and HepaRG cells were evaluated using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide, lactate dehydrogenase (LDH) assay, flow cytometry, and Western blotting. RESULTS: AK-Ex, when administered prior to AAP, increased cell growth and decreased leakage of LDH in a dose-dependent manner in HepG2 and HepaRG cells against AAP-induced hepatotoxicity. AK-Ex increased the level of Bcl-2 and decreased the levels of Bax, Bok and Bik decreased the permeability of the mitochondrial membrane in HepG2 cells intoxicated with AAP. AK-Ex decreased the cleavage of poly (ADP-ribose) polymerase (PARP) and the activation of caspase-9, -7, and -3. CONCLUSIONS: These results demonstrate that AK-Ex downregulates apoptosis via intrinsic and extrinsic pathways against AAP-induced hepatotoxicity. We suggest that AK could be a useful preventive agent against AAP-induced apoptosis in hepatocytes.

부분소결공정에 의한 다공질 탄화규소 세라믹스의 제조 및 특성 (Fabrication of Porous SiC Ceramics by Partial Sintering and their Properties)

  • 김신한;김영욱;윤중열;김해두
    • 한국세라믹학회지
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    • 제41권7호
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    • pp.541-547
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    • 2004
  • 일반적으로 혼합분말의 소결에서 작은 입자에 큰 입자의 첨가는 소결성의 저하를 가져온다. 본 연구에서는 이러한 원리를 이용하여 작은 SiC 입자에 큰 SiC 휘스커 또는 큰 SiC 입자를 첨가하여 소결성을 저하시키고, YAG(Y$_3$A1$_{5}$O$_{12}$)상을 소결 첨가제로 사용함으로서 다공질 SiC 세라믹스를 제조하였다. 제조된 다공질 SiC 세라믹스의 기공율은 큰 입자의 함량과 소결 압력을 제어함으로서 0.3-39% 범위에서 제어할 수 있었다. 기공율은 큰 입자의 함량이 증가함에 따라 증가하였고, SiC 휘스커를 첨가하는 것이 큰 SiC 입자를 첨가하는 것 보다 기공율을 높이는데 효과적이었다. 제조된 다공질 세라믹스에서 기체의 통기성은 기공율이 증가함에 따라 증가하였고, 굽힘강도는 기공율이 증가함에 따라 감소하였다. 기공율이 18% 이상인 다공질 SiC 세라믹스의 경우에 주목할 만한 변형율이 관찰되었다.

졸-겔법을 이용한 고체산화물연료전지의 전해질 박막 제조 및 가스 투과도 (Preparation of Thin Film Electrolyte for Solid Oxide Fuel Cell by Sol-Gel Method and Its Gas Permeability)

  • 손희정;이혜종;임탁형;송락현;백동현;신동열;현상훈
    • 한국세라믹학회지
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    • 제42권12호
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    • pp.827-832
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    • 2005
  • In this study, thin electrolyte layer was prepared by 8YSZ ($8mol\%$ Yttria-Stabilized Zirconia) slurry dip and sol coating onto the porous anode support in order to reduce ohmic resistance. 8YSZ polymeric sol was prepared from inorganic salt of nitrate and XRF results of xerogel powder exhibited similar results $(99.2\pm1wt\%)$ compared with standard sample (TZ-8YS, Tosoh Co.). The dense and thin YSZ film with $1{\mu}m$ thickness was synthesized by coating of 0.7M YSZ sol followed by heat-treatment at $600^{\circ}C$ for 1 h. Thin film electrolyte sintered at $1400^{\circ}C$ showed no gas leakage at the differential pressure condition of 3 atm.