• Journal of the Korea institute for structural maintenance and inspection
• /
• v.15 no.3
• /
• pp.134-141
• /
• 2011

There have been increased economic and societal demands to continuously monitor the integrity and long-term deterioration of civil infrastructures to ensure their safety and adequate performance throughout their life span. However, it is very difficult to continuously monitor the structural condition of the pipeline structures because those are placed underground and connected each other complexly, although pipeline structures are core underground infrastructures which transport primary sources. Moreover, damage can occur at several scales from micro-cracking to buckling or loose bolts in the pipeline structures. In this study, guided wave measurement can be achieved with a self-sensing circuit using a piezoelectric active sensor. In this self sensing system, a specific frequency-induced structural wavelet response is obtained from the self-sensed guided wave measurement. To classify the multiple types of structural damage, supervised learning-based statistical pattern recognition was implemented using the damage indices extracted from the guided wave features. Different types of structural damage artificially inflicted on a pipeline system were investigated to verify the effectiveness of the proposed SHM approach.

• Nutrition Research and Practice
• /
• v.11 no.2
• /
• pp.105-113
• /
• 2017

BACKGROUND/OBJECTIVES: A high-fat diet (HFD) induces obesity, which is a major risk factor for cardiovascular disease and cancer, while a calorie-restricted diet can extend life span by reducing the risk of these diseases. It is known that health effects of diet are partially conveyed through epigenetic mechanism including DNA methylation. In this study, we investigated the genome-wide hepatic DNA methylation to identify the epigenetic effects of HFD-induced obesity. MATERIALS AND METHODS: Seven-week-old male C57BL/6 mice were fed control diet (CD), calorie-restricted control diet (CRCD), or HFD for 16 weeks (after one week of acclimation to the control diet). Food intake, body weight, and liver weight were measured. Hepatic triacylglycerol and cholesterol levels were determined using enzymatic colorimetric methods. Changes in genome-wide DNA methylation were determined by a DNA methylation microarray method combined with methylated DNA immunoprecipitation. The level of transcription of individual genes was measured by real-time PCR. RESULTS: The DNA methylation statuses of genes in biological networks related to lipid metabolism and hepatic steatosis were influenced by HFD-induced obesity. In HFD group, a proinflammatory Casp1 (Caspase 1) gene had hypomethylated CpG sites at the 1.5-kb upstream region of its transcription start site (TSS), and its mRNA level was higher compared with that in CD group. Additionally, an energy metabolism-associated gene Ndufb9 (NADH dehydrogenase 1 beta subcomplex 9) in HFD group had hypermethylated CpG sites at the 2.6-kb downstream region of its TSS, and its mRNA level was lower compared with that in CRCD group. CONCLUSIONS: HFD alters DNA methylation profiles in genes associated with liver lipid metabolism and hepatic steatosis. The methylation statuses of Casp1 and Ndufb9 were particularly influenced by the HFD. The expression of these genes in HFD differed significantly compared with CD and CRCD, respectively, suggesting that the expressions of Casp1 and Ndufb9 in liver were regulated by their methylation statuses.

• Journal of Animal Science and Technology
• /
• v.50 no.4
• /
• pp.445-456
• /
• 2008

Telomeres consist of TTAGGG tandem repeated DNA sequences with specific proteins and locate at chromosome ends. Telomeres are essential for chromosome stability and are related with cell senescence, apoptosis and cancer. Telomerase is a ribonucleoprotein which has a template for the synthesis of telomeric DNA. This study was carried out to analyze the amount of telomeric DNA and telomerase activity in cattle cells. Analysis of the quantity of telomere in lymphocytes was done at different ages, sex and among Korean cattle and Holstein breeds. The telomerase activity was also analyzed in liver, brain, heart, kidney, and testis tissues of fetal calf and of 18 month old cattle. The amount of telomeres in lymphocytes and other tissue cells was analyzed by Quantitative-Fluorescence in situ Hybridization (Q-FISH) technique using a telomeric DNA probe. Telomerase activity was analyzed by Telomeric Repeat Amplification Protocol assay (TRAP). The amount of telomeric DNA on the lymphocytes during the whole life span was decreased along with age. Quantity of telomeres in Korean cattle was significantly higher than that in Holstein breed. The amount of telomeric DNA in males was significantly higher than that in females. Telomerase activity was up-regulated in most bovine tissues during fetal stage, but was down-regulated in most tissues at mature 18 month age except the testis cells. This study indicates that the amount of telomeres and telomerase activity of cells can be used as an age marker or/and a physiological marker of cattle.

• Restorative Dentistry and Endodontics
• /
• v.30 no.3
• /
• pp.184-192
• /
• 2005

Intracanal separation of the rotary files is a serious concern in modern endodontic practice. The objective of this study was to compare the life span and fracture patterns of three NiTi rotary files in molar teeth Mesiobuccal roots of upper molar (n = 150) and mesial roots of lower molar (n = 150) were divided into three groups and each group was prepared with Profile, ProTaper, and K3 respectively. Every file was used until separation and/or deterioration of the cutting blade was happened, and then the number of canals to separation and/or unwinding were recorded. Radiographs and Scanning electon microscope (SEM) photographs were taken to evaluate the patterns of separation. The results were as follows: 1. There were no significant differences in numbers of canals to separation and/or unwinding among the groups. 2. Comparing between flaring files, K3 showed significant lower numbers of canals to separation and/or unwinding (p < 0.05), and there was no significant difference between shaping files 3. Separations of instruments were occurred at the midpoint of curvatures within the canals 4. In SEM observations, ductile fractures were seen in most of cases, characterized by shallow dimples. Additional researches is needed to provide a new guideline that informs the appropriate number of times to use NiTi files.

• KSBB Journal
• /
• v.20 no.3
• /
• pp.233-237
• /
• 2005

In order to investigate the feasibility of 30K protein from silkworm (Bombyx mori) hemolymph (SH) on the proliferation of human cells, a simple separating procedure by anion-exchange chromatography system with Q-Sepharose fast flow gel was established. The 30K protein was eluted with an optimized condition of 0.16 M sodium chloride in 20 mM tris buffer (pH 9.0). The separated 30K protein at three concentrations of 0.04, 0.12, and 0.4 mg/ml was added to the culture medium with various human cells, such as chondrocytes, periosteum-derived cells, and MRC-5 cells, and their growth rates were measured. The cell growth rate at protein concentration of 0.4 mg/ml was always higher than that without 30K protein in all human cells tested, suggesting that the 30K protein has positive effect on the increase of the life span of human cells.

• Journal of Radiation Protection and Research
• /
• v.39 no.4
• /
• pp.187-198
• /
• 2014

I developed a curriculum reflecting the perspectives of students, science teachers, and professionals in order to carry out standardized, fundamental nuclear power and radiation education in schools. Among elementary, middle, and high schools, 78.4%, 78.6%, and 93.1% respectively exhibited (with high frequency) a need for nuclear power and radiation education. The proposed elementary and middle/high school course titles are "Radiation and Life" and "Nuclear Power and Radiation" respectively. The courses are offered at every grade level and span one semester each year. The duration of each weekly class varies; at the elementary, middle, and high school levels classes meet for 40, 45, and 50 minutes respectively. Thin textbooks containing an abundance of cartoons and photos were requested. The starting points for education were fixed at the sixth grade, second year of middle school, and the first year of high school. It was stipulated that the education be separate from the regular curriculum, and encompass a creative and experimental field study based on the principal and science teachers' needs. Similar trends were observable according to grade levels regarding class hours, textbook format, form of education, and educational necessity. A simulation of the devised curriculum revealed an overall goodness of fit totaling $3.88{\pm}0.60$, $3.89{\pm}0.60$, and $3.66{\pm}0.63$ out of five for elementary, middle school, and high school students respectively, which are scores equivalent to 70 and above (out of 100). The significance of this study is that it is the first to propose a curriculum designed to cultivate value judgment based on understanding nuclear power and radiation. However, the realization of nuclear power and radiation education requires that follow-up measures be taken regarding textbook development, amendments to related laws, and the providing of teaching plans.

• Korean journal of applied entomology
• /
• v.23 no.1 s.58
• /
• pp.49-55
• /
• 1984

This study was carried out to investigate the biological performance of the brownplanthopper, Nilaparvata lugens Stal, reared on rice plants at different growth stages; maximum tillering, booting, heading with and without panicles, and milking. The results obtained are as follows: The rice plants at the maximum tillering stage gave the best in the longevity, oviposition period, and the total number of oviposited eggs for the macropterous females, and the worst with the booting stage. For the brachypterous females, however, the best results were obtained from the rice of which their panicles had removed after heading. There was no significant difference in the hachability of eggs and the developmental period of the nymphs in the next generation, but the nymphal mortality was the highest with the milking stage and the lowest with the maximum tillering and heading stage without panicles. The longest life span was shown in males derived on the maximum tillering stage, and the shortest for milking(macropterous type) or booting (brachypterous type) stages. Coefficientes of variances in longevity and number of eggs for the adults emerged from heading stage without panicles were lower than those with panicles intact, and such trend was more obvious in brachypterous adults, especially for the females. The biological performances of the BPH have close relationship with the translocated organic material at the feeding site which showed considerable difference with the growth stages of the rice.

• Journal of the Korean Society for Railway
• /
• v.20 no.2
• /
• pp.241-247
• /
• 2017

Railway bridges with continuously welded rail have a limitation of span length due to track-bridge interaction. In order to overcome this, a sliding slab track system has been developed that comprises with a low-frictional sliding layer between the bridge deck and the track slab to isolate the longitudinal behavior between the bridge and the track. In this study, a real scale track system is prepared to experimentally evaluate the longitudinal frictional behavior. Applied loading rates were 0.2, 1.0, 5.0 and 10mm/min; vertical mass on the track are track slab only, 5,000 and 10,000kg added mass, respectively. Test results showed that the resulting frictional coefficients varied from 0.22 to 0.33. In addition, 10,000 cycle loadings were applied to simulate repetitive sliding to represent 30 years of service life. The frictional coefficient increase was measured and found to be 7% of that of the initial loading stage, which means that the sliding layer is adequate to provide low-frictional behavior for the sliding slab track system. Effects of changes of the frictional coefficient of the sliding layer were analyzed by rail-structure interaction analysis.

• 한국유가공학회:학술대회논문집
• /
• 2004.06a
• /
• pp.21-39
• /
• 2004

Fermented milks have been recognized as healthy foods since ancient times, but those using intestinal bacteria such as Bifidobacterium and lactic acid bacteria (LAB) are even more valuable from the standpoint of view of maintaining health. They have also now come to be recognized as important in the field of preventive medicine. Although advances in the medical sciences in the last 50 years have significantly increased the human lift span, an unfortunate fact is that many of us are now living long enough to experience chronic disorders such as coronary heart disease, hypertension, osteoporosis, diabetes and cancer. In recent years there has been renewed interest in health promotion and disease prevention by incorporating probiotic bacteria into foods to counteract harmful bacteria in the intestinal tract. Therefore, there are now a wide variety of commercial products containing prospective probiotics that claim health-promoting effects, such reductions in large botvel carcinogens and mutagens, antitumor properties, cholesterol-lowering effects, increased lactose digestion, relief from con-stipation, stimulation of immunocomponent cells and enhancement of phagocytosis. Two well-known representative probiotic is LAB and Bifidobaclerium. Traditional probiotic dairy strains of LAB which have been designated as GRAS (Generally Recognized As Safe) bacteria have a long history of safe use and most strains are considered comestible microorganisms with no pathogenic potential. Accordingly, there is considerable interest in extending the range of foods containing probiotic organisms from dairy foods to infant formulas, baby foods, and pharmaceuticals. In addition, the ingestion of probiotics, prebiotics, and symbiotic as wll as combinations of pro- and prebiotics has recently aroused renewed interest as enhancing the beneficial relationship between the host and intestinal microflora in both healthy and diseased indivisuals. Non-communicable chronic diseases such as cancer, cerebral hemorrhage, is chemic heart disease, and diabetes mellitus has recently been recognized as adult diseases in Japan as well as other countries. and are considered to be inevitably associated with aging. These diseases occur as a result of individual life styles. The Japanes Government. Ministry of Health, Labor and Welfare has proposed substituting the term 'adult diseases' with 'lifestyle-related diseases'. It has emphasized the importance of prevention rather than treatment. since the well-known increase in the elderly population in Japan is predicted to result in a variety of socioeconomic problems. n this lecture on the Present status of fermented milk products in Japan, I will report a strategy for the development of fermented milk products in Japan from the standpoint of view of research in Japan on LAB and Bifidobacteria. They could play an important role in preserving human health by controlling intestinal microflora capable of producing toxic effects on the host.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.5 no.1
• /
• pp.28-35
• /
• 1994

Research on biological aspects on adult depression has been subjected to more than 25 years of systematic research, while biologic investigations regarding childhood and adolescent depression are only now being initiated. Although no unifying, explanatory theory of the biologic etiology of childhood depression emerges from the results of studies reviewed above, the findings do support that biological factors may be involved in the genesis of childhood depression. The research reviewed in this paper suggests that age and pubertal factors have major effects in most biological markers of depression. Some of these markers, like sleep EEG and neuroendocrine markers should be broken down by decades during adult life span. Thus, although adult data are very valuable points of departure for biological research on child and adolescent depression, it is very hard to transfer the adult data to prepubertal children and adolescents, ignoring the biological changes that take place in growth and development, pubety and aging. A great deal of work in basic developmental neuroscience remains to be done. It will be crucial for further advances in this field to determine the normal patterns of neurotransmitter interaction in this age group and to study children at high risk for depression. It will be also crucial to use primate models of depressive illness in order to be able to answer the many queations that cannot be investigated in humans for ethical issues. Conclusively, much closer collaboration between developmental and neurobiological and behavioral studies in primates and in humans will be essential for further development.