• Title/Summary/Keyword: Accumulating damage

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Feasibility Study of a Corrugated Steel Protective Structure for Ammunition Test Facility (탄약시험장의 강재 방호구조물 적용성 분석 연구)

  • Han, Jae Duk;Kim, Donghee;Kim, Sungkon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.42 no.5
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    • pp.671-679
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    • 2022
  • Harmful factors such as shock waves and fragments are generated at domestic ammunition testing sites and military shell shooting training sites due to frequent shooting and explosion tests. As a result, complaints from local residents are rapidly increasing, and there is a high risk of damage to facilities and human life. The recently constructed ammunition test site built a test facility for firing artillery and rocket propulsion in a narrow area with a radius of 300 m due to site restrictions, but damage to the facility is accumulating because there is no adequate protective structure. Therefore, in this study, quantitative data on harmful factors such as noise, vibration, shock wave, and thermal effect generated between artillery firing and rocket propulsion tests were measured, and explosion pressure characteristics were analyzed to design a protective structure, and use Autodyn to protect performance. to perform verification.

Nanoparticle Induced Oxidative Stress in Cancer Cells: Adding New Pieces to an Incomplete Jigsaw Puzzle

  • Nogueira, Daniele Rubert;Rolim, Clarice M. Bueno;Farooqi, Ammad Ahmad
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.12
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    • pp.4739-4743
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    • 2014
  • Nanotechnology is an emerging field with many promising applications in drug delivery systems. Because of outstanding developments in this field, rapidly increasing research is directed to the development of nanocarriers that may enhance the availability of drugs to the target sites. Substantial fraction of information has been added into the existing scientific literature focusing on the fact that nanoparticles usually generate reactive oxygen species to a greater extent than micro-sized particles. It is worth mentioning that oxidative stress regulates an array of cell signaling cascades that resulted in cancer cell damage. Accumulating experimental evidence over the years has shown that wide-ranging biological mechanisms are triggered by these NPs in cultured cells due to the unique properties of engineered nanoparticles. In this review, we have attempted to provide an overview of the signaling cascades that are activated by oxidative stress in cancer cells in response to different kinds of nanomaterials, including quantum dots, metallic and polymeric nanoparticles.

The effects of oral antioxidants on the semen of men with idiopathic oligoasthenoteratozoospermia

  • Alahmar, Ahmed T
    • Clinical and Experimental Reproductive Medicine
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    • v.45 no.2
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    • pp.57-66
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    • 2018
  • It has been estimated that approximately 15% of reproductive-age couples suffer from infertility. Male factors contribute to almost half of infertility cases, and in many patients the underlying cause of oligoasthenoteratozoospermia is unknown. Accumulating evidence suggests that oxidative stress plays a role as a contributing factor to male infertility, and reactive oxygen species have been shown to impair sperm function and motility and to damage sperm membrane and DNA. Therefore, this review explored the evidence provided by studies published from 2002 to 2017 on the impact of oral antioxidants (vitamin C, vitamin E, L-carnitine, coenzyme Q10, zinc, selenium, and pentoxifylline) on seminal fluid parameters in men with idiopathic oligoasthenoteratozoospermia. Most of the studies were randomized controlled studies that investigated the effect of single or combined antioxidants and reported improvements in at least one semen parameter. The most noteworthy effect that was found was that the use of multiple antioxidants increased sperm motility and concentration. Nonetheless, there is a lack of agreement on the dose, the duration of treatment, and whether individual or combined oral antioxidants should be used. Therefore, the current review provides evidence supporting the use of oral antioxidants in the treatment of infertile men with idiopathic oligoasthenoteratozoospermia.

Valproic Acid Reduces Reactive Oxygen Species in Fibroblast of X-linked Adrenoleukodystrophy (부신백질형성장애증 섬유모세포에서 발프로산의 항산화능)

  • Kang, Joon Won;Quan, Zhejiu;Jang, Jiho;Kang, Hoon-Chul
    • Journal of the Korean Child Neurology Society
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    • v.23 no.2
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    • pp.45-50
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    • 2015
  • Purpose: X-linked adrenoleukodystrophy (X-ALD) is a fatal, axonal demyelinating, neurodegenerative disease, and is caused by mutations the in ABCD1 (ATP-binding cassette transporter subfamily D member 1). Oxidative damage of proteins caused by very long chain fatty acid accumulating in X-ALD, is an early event in the neurodegenerative cascade. We evaluated valproic acid (VPA) as a possible option for oxidative damage in X-ALD. Method: We generated fibroblast of the childhood cerebral ALD from patient. We evaluated mRNA (ribonucleic acid) level of ABCD2 by real-time polymerase chain reaction, and reactive oxygen species (ROS) levels by flow cytometry. Results: VPA increased expression of ABCD2 in both control and ALD fibroblast. ABCD2 gene mRNA expression was increased 1.76 fold in normal fibroblasts, and 2.22 fold in the X-ALD fibroblasts. ROS levels were decreased in VPA treated X-ALD fibroblast, especially in treated with 1 mM of VPA. ROS levels revealed 13.7 in control fibroblast, on the other hand, 5.83 in X-ALD fibroblast treated with 1 mM of VPA. Conclusion: We propose VPA as a promising novel therapeutic approach in oxidant damage that warrants further clinical investigation in X-ALD.

A Study of Development of Wearable Sports Helmet Device Using IoT Server Technology (IoT 서버 기술을 활용한 웨어러블 스포츠 헬멧 디바이스 설계)

  • Kim, Jin-Kook;Kim, Soo-Hyun
    • Journal of the Korea Convergence Society
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    • v.11 no.4
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    • pp.151-156
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    • 2020
  • The purpose of this study is to design a process for developing wearable sports helmet devices by utilizing IoT server technology, focusing on sports where helmet wear is essential at sports sites. This enables customized training of athletes by continuously accumulating personal biometric information during training, checking players' condition based on data, and informing them of injury prevention and dangerous situations. In addition, the wearable device that can be useful when the training place is likely to damage the physical health due to heat waves or extremes can provide a foundation for improving the performance. Since such technology can be applied not only to the sports field but also to the society such as the industrial field or the underprivileged, it can be expected to be expandable.

Assessment of Selenium Status in Adult Females According to Life Cycle (성인 여성의 생애주기별 셀레늄 영양상태에 대한 평가)

  • 이옥희;문종화;정용삼
    • Journal of Nutrition and Health
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    • v.36 no.5
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    • pp.491-499
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    • 2003
  • Selenium is a strong antioxidant trace mineral, scavenging free radicals. The prevalence of chronic degenerative diseases is increasing in Korean adults with increasing age. The increased cell damage from free radicals has been implicated in the etiology of these diseases, and evidence is accumulating that the low selenium status that comes with advanced aged is involved in the prevalence of age-associated diseases. However, little is known about the selenium status of Koreans, its age-related change and its relationship to dietary nutrient intake. In this study, the serum selenium levels of healthy adult females according to life cycle and its association with blood albumin levels and nutrient intake were examined. Serum selenium level was measured with the Huwo research reactor using the neutron activation analysis method (NAA). The overall proportion of women with selenium deficiency, serum selenium concentrations below 7.0 $\mu\textrm{g}$/dl, was 9.4%. The average serum selenium levels were 12.39 $\mu\textrm{g}$/dl, 9.45 $\mu\textrm{g}$/dl and 9.16 $\mu\textrm{g}$/dl in the young adult, middle-aged and elderly groups, respectively, showing a reduction of selenium status with advancing age. Selenium deficiency was seen only in the elderly group. Generally, serum selenium levels positively or negatively correlated with nutrient intake, but these association patterns differed depending on the age. The nutrients that showed positive correlations with selenium levels were proteins and phosphate in the young adult group (p < 0.05, p < 0.05), and total calcium, potassium and vegetable-origin calcium in the middle-aged group. Vitamin C and fiber were the negative correlated nutrients with serum selenium levels in the elderly group (p < 0.05, p < 0.05). Multiple stepwise regression analysis of the determining factors responsible for selenium status showed that age and serum albumin levels were important factors which explained up to 26.9% variances in serum selenium levels. The average selenium concentrations of Korean adult female subjects were above the deficiency levels in all three age groups. There was a tendency toward decreasing selenium levels as the age of the subjects increased. The factors with the strongest in-fluence on selenium status in healthy adult Korean females were age and serum protein status. (Korean J Nutrition 36(5): 491~499, 2003)

Prevention of Insulation Damage Layer and Shell Corrosion in Thermal Storage Tanks for District Heating (지역난방용 축열조의 단열재 손상과 외각부식 개선방안)

  • Bang, Yong-Eoon;Yoo, Ho-seon
    • Plant Journal
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    • v.10 no.4
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    • pp.35-41
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    • 2014
  • The height and capacity of the thermal storage tank can be decided by the altitude and heat load of the heat supply area. Evaporation in heat pipe can be prevented by pressurizing it with the hydraulic head of the thermal storage tank. In addition, it absorbs the expanded volume from the temperature changes and supplies water to the pipelines in case of the shortage of water. One of the most important roles of the thermal storage tank is a stable heat supply facility. It can control the heat demand by accumulating the surplus heat and supplying in changing heat demand time. The purpose of this thesis is to be helpful for the operation and maintenance of the thermal storage tanks. The study has been carried out for 18 thermal storage tanks, which have been used polyurethane foam as insulation, among 27 tanks in district heating plants. The characteristics of the insulation materials, the reasons for the damages of the insulation and how impact the insulation damages to the corrosion of the thermal storage tank have been studied.

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Analysis of Biological Effect of DBD-type Non-thermal Atmospheric Pressure Plasma on Saccharomyces Cerevisiae

  • Park, Gyung-Soon;Baik, Ku-Yeon;Kim, Jung-Gil;Kim, Yun-Jung;Lee, Kyung-Ae;Choi, Eun-Ha;Uhm, Hwan-Sup;Jung, Ran-Ju;Cho, Kwang-Sup
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.337-337
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    • 2011
  • Application of plasma technology on microbial sterilization has been frequently studied. In spite of accumulating number of studies, many have been focused on bacteria. Reports on eukaryotic yeasts and filamentous fungi are limited. In addition, mechanism of plasma effect still needs to be clarified. In this study, we analyzed the effect of non-thermal atmospheric pressure plasma on the budding yeast, Saccharomyces cerevisiae using DBD-type device. When yeast cells were exposed to plasma (at 2 mm distance) and then cultured on YPD-agar plate, number of cells survived (shown as colony) were reduced proportionally to exposure time. More than 50% reduction in number of colonies were observed after twice exposure of 5min. each. Colonies much smaller than those of control (no plasma exposure) were appeared after twice exposure of 5 min. each. It seems that small colonies are resulted from delayed cell growth due to the damage caused by plasma treatment. Microscopic analysis demonstrates that yeast cells treated with plasma for 5 min. twice have more rough and shrinked shape compared to oval shape with smooth surface of control.

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Diabetic Atherosclerosis and Glycation of LDL(Low Density Lipoprotein)

  • Park, Young-June;Kim, Tae-Woong
    • Preventive Nutrition and Food Science
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    • v.1 no.1
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    • pp.134-142
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    • 1996
  • Diabetes carries an increased risk of atherosclerotic disease that is not fully explained by known car-diovascular risk factors. There is accumulating evidence that advanced glycation of structural proteins, and oxidation and glycation of circulating lipoproteins, are implicated in the pathogenesis of diabetic ather-osclerosis. Reactions involving glycation and oxidation of proteins and lipids are believed to contribute to atherogenesis. Glycation, the nonenzymatic binding of glucose to protein molecules, can increase the ather-ogenic potential of certain plasma constituents, including low density lipoptotein(LDL). Glycation of LDL is significant increased in diabetic patients compared with normal subjects, even in the presence of good glycemic control. Metabolic abnormalities associated with glycation of LDL include diminished recognition of LDL by the classic LDL receptor; increased covalent binding of LDL in vessel walls ; enhanced uptake of LDL by the macrophages, thus stimulating foam cell formation ; increased platelet aggregation; formation of LDL-immune complexes ; and generation of oxygen free radicals, resulting on oxidative damage to both the lipid and protein components of LDL and to any nearby macromolecules. Oxidized lipoproteins are characterzied by cytotoxicity, potent stimulation of foam cell formation by macrophages, and procoagulant effects. Combined glycation and oxidation, "glycoxidation" occurs when oxidative reactions affect the initial products of glycation, and results in irreversible structural alterations of proteins. Glycoxidation is of greatest significance in long lived proteins such as collagen. In these proteins, glycoxidation products, believed to be atherogenic, accumulate with advancing age : in diabetes, their rate of accumulate is accelerated. Inhibition of glycation, oxidation and glycoxidation may form the basis of future antiaterogenic strategies in both diabetic and nondiabetic individuals.dividuals.

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A Case Study on Arranging Archives of Administrative Headquarters of the Jogye Order (조계종 총무원 보존기록물 정리방법에 대한 사례연구)

  • Lee, A-hyun
    • The Korean Journal of Archival Studies
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    • no.6
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    • pp.121-160
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    • 2002
  • This paper reports the project of arranging archives of Administrative Headquarters of the Jogye Order. It illustrates the whole process of preliminary survey, arrangement, appraisal and description of the archives. One of the distinctive features of the project lies in its focus on practical considerations. In other words, it has avoided blindly following theoretical recommendations made by previous efforts. First step of the project has been to review the current state of the archives through preliminary survey as well as analysis of related regulations. Second step has followed to establish actual process of classifying, appraising, describing, filing and designing storage facility management as well as a computerized archival management system. In this process, every concern has been given to prevent records and archives from physical damage and to ensure their intellectual order kept so that archival information could be re-constructed and usability and efficiency of the records could be secured. Major contributions made by the project can be found in that it has reviewed the volume of administrative archives created and held by Jogye Order and improved the overall efficiency of as well as information sharing among personnel at the Headquarter. The most notable accomplishment could be, however, found in that the project has helped the personnel to rediscover their own history from their records, rather than from their memory. From the theoretical perspective of archival science, the meaning of the project can also be found in that it has provided with the starting point toward establishing organizing methodology for organizational archives including religious archives. Arranging archives of an organization requires archivists to respect theories and principles, but at the same time, adequate attention should be paid to reflect idiosyncratic characteristics of the organization. General methods applicable to a wider range of archives could be derived from the very endeavor. Though impossible in a short period of time, it could be accomplished by accumulating theoretical and practical knowledge and experience.