• Title/Summary/Keyword: Sources of stress

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The Screening of Antioxidant Activity in some Korean Medicinal Plants (한국 약식동원 식물자원의 항산화 활성 비교)

  • Park Hong Ju;Lee Sung Hyeon;Kim Dae Ik;Hur Eun Young;Cho Soo Muk
    • The Korean Journal of Community Living Science
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    • v.15 no.4
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    • pp.11-16
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    • 2004
  • This study was conducted to find the powerful free radical scavenging effect in methanol extracts from 35 kinds of Korean medicinal plants obtained from the Plant Extract Bank as natural plant products. Antioxidant activity of the plant extracts was determined by measuring the scavenging effect of 1,1-diphenyl-2-picryl hydrazyl radical (DPPH). In the screening of plant extracts tested, at 200 ppm level, almost all plantex tracts showed significantly high antionidant activity. In the reinvestigation of 15 kinds of Korean medicinal plants at 50 ppm level selected as good sources with good free radical scavenging effect at 200 ppm level, the DPPH scavenging effects were similar to those of L-ascorbic acid in whole plant extract of Fragaria yezoensis (90.4%), in the plant stems and roots extract of Gingko biloba, and the leaves extract of Rhododendron mucronulatum var. ciliatum (90%). The fruits extract of Cornus officinalis showed the strongest antioxidant activity (95%). These results suggest that the methanol extracts from Korean medicinal plants can be a potential source of antioxidants that can be used to control oxidative stress in the body, But further study is needed to measure their safety for consumption

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Characteristic of Electric Generation for the Water Flow Rate in Thermoelctric Generator Using Hot Water (온수를 이용한 열전발전기에서 유량변화에 따른 발전 특성)

  • Woo, Byung-Chul;Lee, Hee-Woong;Suh, Chang-Min
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.10
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    • pp.1333-1340
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    • 2002
  • The objective of this study is to develop a thermoelectric generation system which converts unused energy from close-at-hand sources such as garbage incineration heat and industrial exhaust etc. into electricity. This paper presents applicability of a commercially available thermoelectric generator f3r waster heat recovery. The test facility consists of water heater, pump, thermoelectric module and aluminium tubes and hot and cold water is used as heat source and sink fluids. It is shown that the three components of thermoelectric research exist in manufacturing a thermoelectric generator. The first component is fabrication of thermoelectric materials, the second is manufacturing of thermoelectric generator with 32 thermoelectric modules. The last one is characteristic measuring of thermoelectric generator with 32 thermoelectric modules of two types, cooling and power purpose. It was found that the rate of cold and hot water is 25 and 37 liter per minute and the maximum power of thermoelectric generator is 28Watts and its efficiency is 1.04%.

Global technologies for the removal of water scaling & water recovery - Department of Energy (DOE) USA

  • Ramakrishna, Chilakala;Thriveni, Thenepalli;Whan, Ahn Ji
    • Journal of Energy Engineering
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    • v.27 no.1
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    • pp.21-32
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    • 2018
  • In this paper, we reported the current technologies of water scaling removal and also water recovery from the flue gases, which are funded by Department of Energy (DOE), USA. Globally, water resources are limited due to the climate change. The potential impacts of climate change is food and water shortages. In the $21^{st}$ century, water shortages and pollution are expected to become more acute as populations grow and concentrate in cities. At present, the water stress increases over 62.0 ~ 75.8% of total water basin area and decreases over 19.7 ~ 29.0%. Many renewable energy sources demand secure water resources. Water is critical for successful climate change mitigation, as many efforts to reduce greenhouse gas emissions depend on reliable access to water resources. Water hardness is one of the major challenge to coal power plants. Department of energy (DOE) funded and encouraged for the development of advanced technologies for the removal of hardness of water (scaling) and also water recovery from the flue gases from coal power plants.

Development of a Comprehensive Self-Management Program Promoting Self Efficacy for Type 2 Diabetic Patients (제 2형 당뇨병 환자를 위한 포괄적 자기효능증진 자가관리 프로그램 개발)

  • Park, Ju-Young;Ko, Il-Sun
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.19 no.1
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    • pp.74-86
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    • 2012
  • Purpose: The purpose of this study was to develop a comprehensive self-management program promoting self efficacy for Type 2 diabetic patients. Methods: The study was a methodological research design in which previous related research was reviewed to develop the comprehensive self-management program promoting self efficacy using self efficacy theory. Results: Comprehensive self-management programs promoting self efficacy included the whole range of eight self-management domains: diet, exercise, medication, self-testing of blood glucose, complication or foot, stress, time, and general health, and consisted of four sources of self efficacy: enactive mastery experience, vicarious experience, verbal persuasion, and physiological and affective states, as strategies to promote self efficacy. Developmental methods included, in addition to large and small group education, individual education or counseling, and telephone counseling. Conclusion: Further studies are needed in community health centers or hospitals to establish the effects on self-management compliance and glycemic control of the comprehensive self-management program promoting self efficacy.

Construction of Artificial Biosynthetic Pathways for Resveratrol Glucoside Derivatives

  • Choi, Oksik;Lee, Jae Kyoung;Kang, Sun-Young;Pandey, Ramesh Prasad;Sohng, Jae-Kyung;Ahn, Jong Seog;Hong, Young-Soo
    • Journal of Microbiology and Biotechnology
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    • v.24 no.5
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    • pp.614-618
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    • 2014
  • Resveratrol, which is a polyphenolic antioxidant, is dose-dependent when used to provide health benefits, to enhance stress resistance, and to extend lifespans. However, even though resveratrol has therapeutic benefits, its clinical therapeutic effect is limited owing to its low oral bioavailability. An Escherichia coli system was developed that contains an artificial biosynthetic pathway that produces resveratrol glucoside derivatives, such as resveratrol-3-Oglucoside (piceid) and resveratrol-4'-O-glucoside (resveratroloside), from simple carbon sources. This artificial biosynthetic pathway contains a glycosyltransferase addition (YjiC from Bacillus) with resveratrol biosynthetic genes. The produced glucoside compounds were verified through the presence of a product peak(s) and also through LC/MS analyses. The strategy used in this research demonstrates the first harnessing of E. coli for de novo synthesis of resveratrol glucoside derivatives from a simple sugar medium.

Phospholipase A2, reactive oxygen species, and lipid peroxidation in CNS pathologies

  • Adibhatla, Rao Muralikrishna;Hatcher, J.F.
    • BMB Reports
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    • v.41 no.8
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    • pp.560-567
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    • 2008
  • The importance of lipids in cell signaling and tissue physiology is demonstrated by the many CNS pathologies involving deregulated lipid metabolism. One such critical metabolic event is the activation of phospholipase $A_2$ ($PLA_2$), which results in the hydrolysis of membrane phospholipids and the release of free fatty acids, including arachidonic acid, a precursor for essential cell-signaling eicosanoids. Reactive oxygen species (ROS, a product of arachidonic acid metabolism) react with cellular lipids to generate lipid peroxides, which are degraded to reactive aldehydes (oxidized phospholipid, 4-hydroxynonenal, and acrolein) that bind covalently to proteins, thereby altering their function and inducing cellular damage. Dissecting the contribution of $PLA_2$ to lipid peroxidation in CNS injury and disorders is a challenging proposition due to the multiple forms of $PLA_2$, the diverse sources of ROS, and the lack of specific $PLA_2$ inhibitors. In this review, we summarize the role of $PLA_2$ in CNS pathologies, including stroke, spinal cord injury, Alzheimer's, Parkinson's, Multiple sclerosis-Experimental autoimmune encephalomyelitis and Wallerian degeneration.

A Study on the Report Assessment Patterns of International Undergraduate Students and Instructors (대학보고서에 대한 외국인 학부 유학생과 교수자의 평가 양상 연구)

  • Jang, Mijung;Park, Jung-eun
    • Journal of Korean language education
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    • v.29 no.3
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    • pp.293-324
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    • 2018
  • The purpose of this study was to identify differences in the report assessment patterns of international undergraduate students and instructors. Based on two sample reports, the following differences were confirmed between international students and instructors' assessments of reports. First, instructors and students showed no differences in their assessments of the well-formatted report. However, the two groups exhibited differences in their assessments of the report that was not well formatted in that students evaluated the report more highly than instructors did. Second, instructors and students exhibited notable differences in their assessments of items such as citation, logic, and expression. This may have been because students lacked knowledge on citation methods and the use of grounds for arguments based on citation methods and topics. Third, students and instructors showed differences in their areas of focus when evaluating reports. Instructors mostly focused on the main topics of each report, whereas students focused on supporting details for the main topics. Based on these findings, instructors need to emphasize the following areas in educating international undergraduate students on report writing. First, they should stress proper source citation. They should provide frequent guidance on how to accurately cite sources. Second, they should help students to first think about the overall form and content of their reports. Instructors should emphasize that having a logical overall report structure and content that is relevant to the subject is more important in general than grammar or accuracy of vocabulary.

Life Prediction by Retardation Behavior of Fatigue Crack and its Nondestructive Evaluation (피로균열의 지연거동에 따른 수명예측 및 비파괴평가)

  • Nam, Ki-Woo;Kim, Seon-Jin
    • Journal of Ocean Engineering and Technology
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    • v.13 no.3 s.33
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    • pp.36-48
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    • 1999
  • Fatigue life and crack retardation behavior after penetration were experimentally examined using surface pre-cracked specimens of aluminium alloy 5083. The Wheeler model retardation parameter was used successfully to predict crack growth behavior after penetration. By using a crack propagation rule, the change in crack shape after penetration can be evaluated quantitatively. Advanced, waveform-based acoustic emission (AE) techniques have been successfully used to evaluate signal characteristics obtained form fatigue crack propagation and penetratin behavior in 6061 aluminum plate with surface crack under fatigue stress. Surface defects in the structural members are apt to be origins of fatigue crack growth, which may cause serious failure of the whole structure. The nondestructive analysis on the crack growth and penetration from these defects may, therefore, be one of the most important subjects on the reliability of the leak before break (LBB) design. The goal of the present study is to determine if different sources of the AE could be identified by characteristics of the waveforms produced from the crack growth and penetration. AE signals detected in four stages were found to have different signal per stage. With analysis of waveform and power spectrum in 6061 aluminum alloys with a surface crack, it is found to be capabilities on real-time monitoring for the crack propagation and penetration behavior of various damages and defects in structural members.

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Evaluation of Chloroplast Genotypes of Korean Cucumber Cultivars (Cucumis sativus L.) Using sdCAPS Markers Related to Chilling Tolerance

  • Ali, Asjad;Yang, Eun Mi;Lee, Sun Young;Chung, Sang-Min
    • Horticultural Science & Technology
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    • v.31 no.2
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    • pp.219-223
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    • 2013
  • DNA markers can determine the genotype of many species. Single nucleotide polymorphism (SNP) detection is difficult without sequencing but it becomes easier with sdCAPS method. Here an experiment was performed for developing molecular markers using two SNPs, CSatpB-SNP and CSycf1-SNP, of chloroplast in cucumber plants. Properly designed primers with nucleotide sequences for restriction enzymes proved success of PCR and efficacy of digestion by the restriction enzymes. Then these markers were used to study the genotyping of cucumber breeding lines and cultivars obtained from various sources in respect of their chilling stress response. We confirmed that a U.S. cucumber line, 'NC76' known to possess a nuclear factor for the chilling tolerance showed the chloroplast genotypes related to chilling tolerance. However all Korean cucumber cultivars tested in this study showed the chloroplast genotypes related to chilling susceptibility. In conclusion, to develop chilling tolerant cucumber, both maternal and a nuclear factors related to chilling tolerance should be transferred from 'NC76' when 'NC76' is used as a female source and other elite lines as recurrent parents.

XPERNATO-TOX: an Integrated Toxicogenomics Knowledgebase

  • Woo Jung-Hoon;Kim Hyeoun-Eui;Kong Gu;Kim Ju-Han
    • Genomics & Informatics
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    • v.4 no.1
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    • pp.40-44
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    • 2006
  • Toxicogenomics combines transcriptome, proteome and metabolome profiling with conventional toxicology to investigate the interaction between biological molecules and toxicant or environmental stress in disease caution. Toxicogenomics faces the problems of comparison and integration across different sources of data. Cause of unusual characteristics of toxicogenomic data, researcher should be assisted by data analysis and annotation for getting meaningful information. There are already existing repositories which claim to stand for toxicogenomics database. However, those just contain limited abilities for toxicogenomic research. For supporting toxicologist who comes up against toxicogenomic data flood, now we propose novel toxicogenomics knowledgebase system, XPERANTO-TOX. XPERANTO-TOX is an integrated system for toxicogenomic data management and analysis. It is composed of three distinct but closely connected parts. Firstly, Data Storage System is for reposit many kinds of '-omics' data and conventional toxicology data. Secondly, Data Analysis System consists of analytical modules for integrated toxicogenomics data. At last, Data Annotation System is for giving extensive insight of data to researcher.