• Title/Summary/Keyword: EN-ratio

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Amino Acid-Based Material for the Complementary Therapy of Decubitus Ulcers

  • Nogueira, Frederico;Gouveia, Isabel C.
    • Journal of Microbiology and Biotechnology
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    • v.27 no.4
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    • pp.747-758
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    • 2017
  • Chronic wounds, pressure sores, lesions, and infections of microbial origin in bedridden, paralyzed, or malnutrition patients remain the object of study of many researchers. A variety of factors behind the development of these disorders are related to the patient's immune system, making it unable to respond effectively to the treatment of the wound. These factors can be properly controlled, giving particular importance to the ethiology and stage of the wound, as well as the time periods corresponding to the replacement of the dressings. The present research reports a novel foam/soft material, ${{\small}L}$-Cys-g-PCL, with an application for decubitus/pressure ulcers, especially for wounds with a difficult healing process due to infections and constant oxidation of the soft tissues. During this work, the interactions between S. aureus and ${{\small}L}$-Cys-g-PCL foam were studied under conditions that simulate decubitus ulcers; namely, pH and exudate. The effects of duration of grafting (1 or 8 h) and pH (7.0 and 8.9) on wettability, surface energy, swelling, and porosity were also evaluated. Results showed an effective microbicidal activity exhibiting an inhibition ratio of 99.73% against S. aureus. This new ${{\small}L}$-Cys-g-PCL soft material showed saftey to contact skin, ability to be shaped to fill in sunken holes (craters) - pressure ulcers stage III - and to act as a smart material responsive to pH, which can be tailored to develop better swelling properties at alkaline pH where exudates are normally higher, so as to address exudate self-cleaning and prevention of desiccation.

Performance of carbon fiber added to anodes of conductive cement-graphite pastes used in electrochemical chloride extraction in concretes

  • Pellegrini-Cervantes, M.J.;Barrios-Durstewitz, C.P.;Nunez-Jaquez, R.E.;Baldenebro-Lopez, F.J.;Corral-Higuera, R.;Arredondo-Rea, S.P.;Rodriguez-Rodriguez, M.;Llanes-Cardenas, O.;Beltran-Chacon, R.
    • Carbon letters
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    • v.26
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    • pp.18-24
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    • 2018
  • Pollution of chloride ion-reinforced concrete can trigger active corrosion processes that reduce the useful life of structures. Multifunctional materials used as a counter-electrode by electrochemical techniques have been used to rehabilitate contaminated concrete. Cement-based pastes added to carbonaceous material, fibers or dust, have been used as an anode in the non-destructive Electrochemical Chloride Extraction (ECE) technique. We studied the performance of the addition of Carbon Fiber (CF) in a cement-graphite powder base paste used as an anode in ECE of concretes contaminated with chlorides from the preparation of the mixture. The experimental parameters were: 2.3% of free chlorides, 21 days of ECE application, a Carbon Fiber Volume Fraction (CFVF) of 0.1, 0.3, 0.6, 0.9%, a lithium borate alkaline electrolyte, a current density of $4.0A/m^2$ and a cement/graphite ratio of 1.0 for the paste. The efficiency of the ECE in the traditional technique using metal mesh as an anode was 77.6% and for CFVF of 0.9% it was 90.4%, with a tendency to increase to higher percentages of the CFVF in the conductive cement-graphite paste, keeping the pH stable and achieving a homogeneous ECE in the mass of the concrete contaminated with chlorides.

Dose modeling and its Application of Ir-192 for substitution of Ralstron Brachytherapy source (Ralstron 선원대체형 Iridium-192 선원의 선량모델링과 응용)

  • 김옥배;최태진;김진희;이호준;박정호;김성규;조운갑;한현수
    • Progress in Medical Physics
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    • v.11 no.2
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    • pp.131-139
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    • 2000
  • We designed high dose rate Ir-192 source which was prepared for substitute the Co-60 source in Ralstron unit (Simatsu, Japan) which is supplied for cervical cancer treatment. The source dimension is 1.5 mm in a diameter and 1.5mm thickness of cylinder and encapsulated with 3 mm diameter of stainless steel(SUS316L) to substituted for the Co-60 source size. The Ir-192 source was prepared the dose model for tissue dose computation through the experimental determination of apparent activity and applied the empirical tissue correction factors extended to 20cm distance. The tissue dose model was applied the 4.69 R/cm-mCi-hr gamma constant and the ratio of energy absorption coefficient of water to that of air showed 1.112 include filteration of the self-absorptions. In this experiments, we prepared the dose computation software to clinical usefulness.

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Mechanical Properties of Energy Efficient Concretes Made with Binary, Ternary, and Quaternary Cementitious Blends of Fly Ash, Blast Furnace Slag, and Silica Fume

  • Kim, Jeong-Eun;Park, Wan-Shin;Jang, Young-Il;Kim, Sun-Woo;Kim, Sun-Woong;Nam, Yi-Hyun;Kim, Do-Gyeum;Rokugo, Keitetsu
    • International Journal of Concrete Structures and Materials
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    • v.10 no.sup3
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    • pp.97-108
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    • 2016
  • When the energy performance of concrete is substantially higher than that of normal type concrete, such concrete is regarded as energy efficient concrete (WBSCSD 2009). An experimental study was conducted to investigate mechanical properties of energy efficient concrete with binary, ternary and quaternary admixture at different curing ages. Slump test for workability and air content test were performed on fresh concretes. Compressive strength, splitting tensile strength were made on hardened concrete specimens. The mechanical properties of concrete were compared with predicted values by ACI 363R-84 Code, NZS 3101-95 Code, CSA A23.3-94 Code, CEB-FIP Model, EN 1991, EC 2-02, AIJ Code, JSCE Code, and KCI Code. The use of silica fume increased the compressive strengths, splitting tensile strengths, modulus of elasticities and Poisson's ratios. On the other hand, the compressive strength and splitting tensile strength decreased with increasing fly ash.

Helicobacter pylori Infection and the Risk of Colorectal Adenoma and Adenocarcinoma: an Updated Meta-analysis of Different Testing Methods

  • Chen, Yao-Sheng;Xu, Song-Xin;Ding, Yan-Bing;Huang, Xin-En;Deng, Bin
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.12
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    • pp.7613-7619
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    • 2013
  • Background and Aims: Helicobacter pylori infection may be associated with an increased risk of colorectal carcinoma. However, as most studies on this subject were relatively small in size and differed at least partially in their designs, their results remain controversial. In this study, we aimed to carry out a meta-analysis to evaluate the potential association of H. pylori infection with colorectal adenoma and adenocarcinoma risk, covering all of the different testing methods. Methods: We conducted a search in PubMed, Medline, EBSCO, High Wire Press, OVID, and EMBASE covering all published papers up to March 2013. According to the established inclusion criteria, essential data were then extracted from the included studies and further analyzed by a systematic meta-analysis. Odds ratios were employed to evaluate the relationship between H. pylori infection and the risk of colorectal neoplasms. Results: Twenty-two studies were included, and the odds ratio for the association between H. pylori infection and colorectal cancer was 1.49 (95% confidence interval 1.30-1.72). No statistically significant heterogeneity was observed. Publication bias was ruled out. Conclusion: The pooled data suggest H. pylori infection indeed increases the risk of colorectal adenoma and adenocarcinoma.

Fluid intake, hydration status and its association with cognitive function among adolescents in Petaling Perdana, Selangor, Malaysia

  • Tung, Serene En Hui;Ch'ng, Yi Zhang;Karnan, Thaneswary V;Chong, Pei Nee;Zubaidah, Jamil Osman;Chin, Yit Siew
    • Nutrition Research and Practice
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    • v.14 no.5
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    • pp.490-500
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    • 2020
  • BACKGROUND/OBJECTIVES: A cross-sectional study was undertaken to evaluate fluid intake and hydration status in association with cognitive function among 230 adolescents (10-14 years of age) in Petaling Perdana, Selangor, Malaysia. SUBJECTS/METHODS: Urine color was used to measure hydration status, while fluid intake was assessed using the 15-item beverage intake questionnaire. Cognitive function was assessed using the Wechsler Intelligence Scale for Children, Fourth Edition. RESULTS: More than half of the adolescents were mildly or moderately dehydrated (59.6%) and only one-third (33.0%) were well hydrated. Among the daily fluid types, intakes of soft drinks (r = -0.180; P = 0.006), sweetened tea (r = -0.184; P = 0.005) and total sugar-sweetened beverages (SSBs) (r = -0.199; P = 0.002) were negatively correlated with cognitive function. In terms of hydration status, cognitive function score was significantly higher (F-ratio = 4.102; P = 0.018) among hydrated adolescents (100.38 ± 12.01) than in dehydrated (92.00 ± 13.63) counterparts. Hierarchical multiple linear regression analysis, after adjusting for socio-demographic factors, showed that soft drinks (β = -0.009; P < 0.05) and sweetened tea (β = -0.019; P < 0.05) negatively predicted cognitive function (ΔR2 = 0.044). When further control for sources of fluid, hydration status (β = -2.839; P < 0.05) was shown to negatively predict cognitive function (ΔR2 = 0.021). The above variables contributed 20.1% of the variance in cognitive function. CONCLUSIONS: The results highlight the links between fluid intake (soft drinks, sweetened tea, total SSBs) and hydration status with cognitive function in adolescents. Interventions aimed at decreasing the consumption of SSBs and increasing hydration status through healthy fluid choices, such as water, could improve cognitive performance in adolescents.

Studies of Valve Lifer for Automotive Heavy Duty Diesel Engine by Ceramic Materials II. Development of SiC Valve Lifter by Injection Molding Method (Ceramic 재질을 이용한 자동차용 대형 디젤엔진 Valve Lifter 연구 II. 사출성형에 의한 탄화규소질 Valve Lifter 개발)

  • 윤호욱;한인섭;임연수;정윤중
    • Journal of the Korean Ceramic Society
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    • v.35 no.2
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    • pp.172-179
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    • 1998
  • Valve lifter namely tappet is supported by lifter hole which is located upper side of camshaft in cylinder block transforms rotatic mvement of camshaft into linear movement and helps to open and shut the en-gine valve as an engine parts. The face of valve lifter which is continuously contacting with camshaft brings about abnormal wears such as unfair wear and early wear because it is severely loaded in the valve train system. These wears act as a defect like over-clearance and cause imperfect combustion of fuel during the valve lifting in the combustion chamber. Consequently this imperfect combustion makes the engine out-put decrease and has cause on air pollution. To prevent these wears therefore The valve lifter cast in me-tal developed into SiC ceramics valve lifter which has an excellence in wear and impact resistance As a results the optimum process conditions like injection condition mixture ratio and debonding process could be established. After sintering fine-sinered dual microstructure in which prior ${\alpha}$-SiC matches well with new SiC(${\beta}$-SiC) produced by reaction among the ${\alpha}$-SiC carbon and silicon was obtained. Based on the study it is verified that mechanical properties of SiC valve lifter are excellent in Vickers hardness 1100-1200 bending strength (300-350 Pa) fracture toughness(1.5-1.7 Mpa$.$m1/2) Through engine dynamo test-ing SiC valve lifter and metal valve lifter are examined and compared into abnormal phenomena such as early fracture unfair and early wear. It is hoped that this research will serve as an important springboard for the future study of heavy duty diesel engine parts developed by ceramics which has a good wear resis-tance relaibility and lightability.

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Ultrasound Score to Select Subcentimeter-sized Thyroid Nodules Requiring Ultrasound-guided Fine Needle Aspiration Biopsy in Eastern China

  • Cheng, Pu;Chen, En-Dong;Zheng, Hua-Min;He, Qiu-Xiang;Li, Quan
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.8
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    • pp.4689-4692
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    • 2013
  • Ultrasound-guided fine needle aspiration biopsy (FNAB) is a costly diagnostic item with a low yield in identifying the tiny proportion of nodules that actually represent malignant disease. Our aim through this study was to obtain an ultrasound (US) score for selecting subcentimeter-sized thyroid nodules requiring FNAB in eastern China. Some 248 patients for a total of 270 thyroid nodules less than 1 cm in diameter underwent FNAB and subsequent surgery from January 2006 to March 2012 at our hospital. The clinicopathological and US data from all the nodules were analyzed retrospectively. An US score was developed on the basis of independent predictive factors for malignancy. Irregular shape, hypoechogenicity, no well-defined margin, presence of calcifications and ratio between antero-posterior and transversal diameters (AP/TR) ${\geq}1$ were independent predictive factors for malignancy on logistic regression analysis. US score were statistically significant, with ${\leq}2$ favoring benignancy with an 80.3% sensitivity and a 72.7% specificity. US score is useful for differentiating between malignant and benign subcentimeter-sized thyroid nodules. We suggest FNAB for nodules when the US score is higher than 2.

The rs61764370 Functional Variant in the KRAS Oncogene is Associated with Chronic Myeloid Leukemia Risk in Women

  • Gutierrez-Malacatt, Humberto;Ayala-Sanchez, Manuel;Aquino-Ortega, Xochitl;Dominguez-Rodriguez, Jacqueline;Martinez-Tovar, Adolfo;Olarte-Carrillo, Irma;Martinez-Hernandez, Angelica;Cecilia, Contreras-Cubas C;Orozco, Lorena;Cordova, Emilio J
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.4
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    • pp.2265-2270
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    • 2016
  • Background: Chronic myeloid leukemia (CML) is one of the most frequent hematopoietic malignancies in the elderly population; however, knowledge is limited regarding the genetic factors associated with increased risk for CML. Polymorphisms affecting microRNA (miRNA) biogenesis or mRNA:miRNA interactions are important risk factors in the development of different types of cancer. Thus, we carried out a case-control study to test the association with CML susceptibility of gene variants located in the miRNA machinery genes AGO1 (rs636832) and GEMIN4 (rs2740348), as well as in the miRNA binding sites of the genes BRCA1 (rs799917) and KRAS (rs61764370). Materials and Methods: We determined the genotype of 781 Mexican-Mestizo individuals (469 healthy subjects and 312 CML cases) for the four polymorphisms using TaqMan probes to test the association with CML susceptibility. Results: We found a borderline association of the minor homozygote genotype of the KRAS_rs61764370 polymorphism with an increased risk for CML susceptibility (P = 0.06). After gender stratification, this association was significant only for women (odds ratio [OR] = 13.41, P = 0.04). The distribution of the allelic and genotypic frequencies of the four studied SNPs was neither associated with advanced phases of CML nor treatment response. Conclusions: To the best of our knowledge, this study is the first to show a significant association of the KRAS_rs61764370 SNP with CML. To further determine such an association of with CML susceptibility, our results must be replicated in different ethnic groups.

A Study on Electrochemical Regeneration of Waste Iron-chloride Etchant and Copper Recovery (전기화학 반응에 의한 염화철 폐식각액의 재생 및 구리 회수에 관한 연구)

  • Kim, Seong-En;Lee, Sang-Lin;Kang, Sin-Choon;Kim, I-Cheol;Sheikh, Rizwan;Park, Yeung-Ho
    • Clean Technology
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    • v.18 no.2
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    • pp.183-190
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    • 2012
  • Electrochemical regeneration of the iron chloride waste solution from PCB etching reduces environmental contamination and produces copper as by-product, so the economic feasibility is high. But iron chloride waste solution contains iron and copper and the reactions occurring in the electrolytic cell are complicated. In this work, the oxidation of iron chloride and copper deposition were examined through batch electrolysis and the optimum conditions of the process parameters were found. The oxidation of ferrous chloride was achieved easily to the desired level. The copper deposition efficiency was high in the reaction using the carbon cathode when the copper density was 12 g/L with the electric current density of $350mA/cm^2$, and the ratio of the $Fe^{2+}$ ion was high. In addition, the possibility of the scale-up was confirmed in continuous operation of bench reactor using the optimum conditions obtained.