• Korean Journal of Environmental Agriculture
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• v.18 no.3
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• pp.236-244
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• 1999

A feasibility study was performed to examine the agronomic application of treated sewage on paddy rice culture by field experiment. The domestic sewage was treated by the constructed wetland system which was in subsurface flow type and consisted of sand and macrophyte. The effluent of the wetland system was adjusted to maintain the total nitrogen concentration below $25mgL^{-1}$ and used for irrigation water. Four treatments include (1) irrigation of treated sewage after concentration adjusted with conventional fertilization (TWCF), (2) irrigation of treated sewage after concentration adjusted with half of the conventional fertilization (TWHF), (3) irrigation of treated sewage after concentration adjusted without fertilization (TWNF), and (4) irrigation of treated sewage as it was without fertilization (SWNF). These cases were compared to the control case of tap water irrigation with conventional fertilization (Control). Generally, addition of the treated sewage to the irrigation water showed no adverse affect on paddy rice culture, and even improvement was noticed in both growth and yields. TWCF showed the best result and the yields exceed the Control in about 10%. Overall performance of the treatments was TWCF, Control, TWHF, TWNF, and SWNF in decreasing order. From this study, it appears that reuse of treated sewage as a supplemental irrigation water could be feasible and practical alternative for ultimate sewage disposal which often causes water quality problem to the receiving water body. For full scale application, further study is recommended on the specific guidelines of major water quality components and public health.

• Journal of Bio-Environment Control
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• v.1 no.2
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• pp.154-161
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• 1992

This experiment was carried oui to determine the relativeness between growth, yield characters and bio-informations as influenced by the spray and rest time intervals of nutrient solution. Tomato(Lycopersicon esculentum Mill.) were grown in aeroponic system on a misting schedule of continuously 60 sec, 30 sec and 10 sec at 10 min intervals with full strength Yamazaki's solution recommended for tomato production. The results obtained were as follows : 1. Leaf area was highest in the plot of 30 sec spray and 10 min rest while the forest one was the plot of 60 sec spray and 10 min rest. Growth characteristics in terms of dry weight of each organ, number of flower, number of flower setted and fruit dry weight were greater in the plot of 30 sec spray and 10 min rest than the other treatments. 2. The number of flower increased with decreasing dry weight but number of flower sorted was not significantly different among treatment except for the plot of 60 sec spray and 10 min rest. 3. Leaf dry weight and fruit dry weight were highly correlated so that 30 sec spray and 10 min rest plot which is the highest fruit dry weight showed the largest leaf area. Continuously sprayed plot reduced markedly the fruit dry weight compared with leaf area. Optimum spray and rest time of nutrient solution in the range of this experiment was determined as 30 sec spray and 10 min rest. 4. Solar radiation within glasshouse during daytime reduced severely compared with outdoor one and air temperature within greenhouse was higher than the leaf temperature of tomato plant. The changes of environmental factors, solar radiation, temperature were accompanied with the sensitive change of bio-informations of tomato leaf Especially differences of spray intervals of nutrient solution affected greatly to the changes of bio-informations : leaf water potential, stomatal resistance and leaf temperature etc. 5. The changing patterns of leaf growth as influenced by the spray and rest intervals of nutrient solution were closely related to the leaf water potential, stomatal resistance and leaf temperature. Feasibility was demonstrated that measurement of bio-information of tomato leaf as influenced by the change of environmental factors could be expected to the amount of growth and fruit yield.

• Journal of Animal Environmental Science
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• v.13 no.1
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• pp.13-20
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• 2007

Sawdust biofiltration is an emerging bio-technology for control of ammonia emissions including compost odors from composting of biological wastes. Although sawdust is widely used as a medium for bulking agent in composting system and for microbial attachment in biofiltration systems, the performance of agitated bed composting and sawdust biofiltration are not well established. A pilot-scale composting of hog manure amended with sawdust and sawdust biofiltration systems for practical operation were investigated using aerated and agitated rectangular reactor with compost turner and sawdust biofilter operated under controlled conditions, each with a working capacity of approximately $40m^3\;and\;4.5m^3$ respectively. These were used to investigate the effect of compost temperature, seed germination rate and the C/N ratio of the compost on ammonia emissions, compost maturity and sawdust biofiltration performance. Temperature profiles showed that the material in three runs had been reached to temperature of 55 to $65^{\circ}C$ and above. The ammonia concentration in the exhaust gas of the sawdust biofilter media was below the maximum average value as 45 ppm. Seed germination rate levels of final compost was maintained from 70 to 93% and EC values of the finished compost varied between 2.8 and 4.8 ds/m, providing adequate conditions for plant growth.

• Journal of Life Science
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• v.16 no.6
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• pp.984-988
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• 2006

Lipopolysaccharide(LPS) was posttreated after the 14 day-pretreatment of Ulva lactuca fractions(ULF), and their correlativity to enzymatic activity alteration was investigated in the liver of rats. ULF was intraperitoneally administered into rats at dose of $1m{\ell}/kg$ of 100 mg/kg concentration for 14 days. On the day 15, $1m{\ell}/kg$ of LPS was injected. The corelativity was examined by measuring the changed values of superoxide dismutase(SOD) in mitochondrial fraction and catalase(CAT), glutathione peroxidase(GPx) in liver homogenate. The results showed that LPS treatment decreased the high values of SOD, CAT, GPx to the low values, but ULF pretreatment increased the low values of SOD, CAT, GPx to the high values. It was suggested that ULF, LPS and antioxidative enzymes like SOD, CAT, GPx had the corelativity of the high-low-high pattern and that the ULF pretreatment played the proper preventive role in the protection against the LPS treatment-induced enzymatic inactivity in the water fraction.

• Journal of Life Science
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• v.26 no.1
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• pp.50-58
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• 2016

The root bark of Ulmus macrocarpa has been used in traditional medicine for the treatment of various diseases such as edema, infection and inflammation. Nevertheless, the biological activities and underlying mechanisms of the immunomodulatory effects remain unclear. In this study, as part of our ongoing screening program to evaluate the immunomodulatory potential of new compounds from traditional medicinal resources, we investigated the effects of U. macrocarpa water extract (UME) on immune modulation in a murine RAW 264.7 macrophage model. As immune response parameters, the productions of as nitric oxide (NO) and cytokines such tumor necrotic factor (TNF)-α, interleukin (IL)-1β and IL-10 were evaluated. Although the release of IL-1β remained unchanged in UME-treated RAW 264.7 macrophages, the productions of NO, TNF-α and IL-10 were significantly increased, along with the increased expression of inducible NO synthase, TNF-α and IL-10 expression at concentrations with no cytotoxicity. UME treatment also induced the nuclear translocation of nuclear factor κB (NF-κB), and phosphorylation of Akt and mitogen-activated protein kinases (MAPKs) indicating that UME activated macrophages through the activation of NF-κB, phosphoinositide-3-kinase (PI3K)/Akt and MAPKs signaling pathways in RAW 264.7 macrophages. Furthermore, pre-treatment with UME significantly attenuated the production of NO, but not TNF-α, IL-1β and IL-10, in lipopolysaccharide-stimulated RAW 264.7 cells suggesting that UME may be useful in preventing inflammatory diseases mediated by excessive production of NO. These findings suggest that the beneficial therapeutic effects of UME may be attributed partly to its ability to modulate immune functions in macrophages.

• Journal of the Korean Geographical Society
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• v.31 no.4
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• pp.699-715
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• 1996

This paper examines the cross-sectional development of children's conception of place. Previous research by Piaget and Weil, Jahoda, Daggs has questioned how young children develop the ablity to comprehend place. Oral interview and graphic test were made vy the children at the age of 5-14, in order to attain information on their knowledge, understanding and feeling about place. These data were used ti indentify developmental stages through cluster analysis. The results suggest that young children's conception of place develops with an identifiable 4 stages. There is no significant difference in development of conception of place between the 2nd year of kindergarten and the 1st year of elementary school, or the between the 5th, 6th year of elementary school and 1st, 2nd year of middle school. Rather, the 4th year of elementary school is an important and crucial truning point in the development of children's conception of place. It is concluded that children's conception of place develops in line with Piaget's general cognitive developmental theory in which the pre-conceptual stage ends at age 7 and the concrete-operation stage starts at age 11 to 12.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.3
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• pp.266-272
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• 2009

Statement of problem: The number of edentulous patients is increasing due to an aging society, which leads to increased demands and interests on implant restorations. Implant restorations are an effective treatment method for both complete and partially edentulous patients, and the success rate has been reported to be high. But because of the increased use of implants in various situations have resulted in frequent reports of failures on implant restorations. Various efforts to overcome these failures have been made. Purpose: The aim of this study was to investigate the statistic survival rate of dental implants on patients who were treated at Dankook University Dental Hospital during the past 10 years based on their charts. Materials and methods :The research was made for two different periods of time; The first investigation was for patients from August, 1998 to August, 2003 and the second was for patients from September, 2003 to April, 2007. Information on the number of implants placed, the location and distribution of implants, the duration between the first and second surgery, and the survival rate of implants were investigated from the patients'charts. Results: 1. According to the first investigation, 1680 implants were placed on 612 patients and the second investigation showed 2438 implants placed on 933 patients. Thus a total of 4118 implants on 1545 patients. 2. Among the 1545 patients, 884 patients were male (57.2 %) and 661 patients were female (42.8%). Out of 4118 implants, 1739 implants (42.2%) were placed on the maxilla, and 2379 implants (57.8%) on the mandible. Implants were placed most frequently in the posterior region of the mandible. A total of 2043 implants (53.2%) were placed in this region. 3. According to the first investigation, 57 out of 1680, implants failed, while from the second investigation, 17 out of 2438 implants were reported as failure. In total, 74 implants failed, which results in a 98.2% survival rate. 4. The average duration between the first and the second surgeries in maxillas decreased from 7.4 months to 6.8 months. The duration also decreased from 5.6 months to 5.0 months in mandibles. Conclusion: As shown in the results, the number of placed implants and the survival rate of implants were higher in the second investigation than that of the first investigation. And the time spent after the first surgery to the second surgery was less in the second investigation. Consequently, it can be presumed that the demand and consumption of dental implants as well as the survival rate will increase in the future.

• Journal of Radiation Protection and Research
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• v.38 no.4
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• pp.214-227
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• 2013

Computed tomographic scan as a screening procedures in asymptomatic individuals has seen a steady increase with the introduction of multiple-raw detector CT scanners. This report provides a brief review of the current controversy surrounding CT cancer screening, with a focus on the radiation induced cancer risks and clinical efficacy. 1. A large study of patients at high risk of lung cancer(the National Lung Screening Trial[NLST]) showed that CT screening reduced cancer deaths by 20%(1.33% in those screened compared with 1.67% in those not screened). The rate of positive screening tests was 24.2% and 96.4% of the positive screening results in the low-dose CT group were false-positive. Radiation induced lung cancer risk was estimated the most important in screening population because ERR of radiation induced lung cancer does not show the decrease with increasing age and synergistic connection between smoking and radiation risk. Therefore, the radiation risk may be on the same order of magnitude as the benefit observed in the NLST. Optimal screening strategy remain uncertain, CT lung cancer screening is not yet ready for implementation. 2. Computed tomographic colonography is as good as colonoscopy for detecting colon cancer and is almost as good as colonoscopy for detecting advanced adenomas, but significantly less sensitive and specific for smaller lesions and disadvantageous for subsequent therapeutic optical colonoscopy if polyps are detected. The average effective dose from CT colonography was estimated 8-10 $mS{\nu}$, which could be a significant dose if administered routinely within the population over many years. CT colonography should a) achieve at least 90% sensitivity and specificity in the size category from 6 and 10 mm, b) offer non-cathartic bowl preparation and c) be optimized and standardized CT parameters if it is to be used for mass screening. 3. There is little evidence that demonstrates, for whole-body scanning, the benefit outweighs the detriment. This test found large portion of patient(86~90.8%) had at least one abnormal finding, whereas only 2% were estimated to have clinically significant disease. Annual scans from ages 45 to 75 years would accrue an estimated lifetime cancer mortality risk of 1.9%. There is no group within the medical community that recommends whole-body CT. No good studies indicate the accuracy of screening CT, at this time. The benefit/risk balance for any of the commonly suggested CT screening techniques has yet to be established. These areas need further research. Therefore wild screening should be avoided.

• Tuberculosis and Respiratory Diseases
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• v.59 no.4
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• pp.406-412
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• 2005

Background : Recently, two commercialized whole-blood assays, $QuantiFERON^{(R)}-TB$ Gold (QFT) and T $SPOT-TB^{(R)}$ (SPOT), which measure the $IFN-{\gamma}$ released in the whole blood after being incubation with mycobacterial antigens, were approved for the diagnosis of a latent tuberculosis infection (LTBI). However, there is data on whether or not the previously used PPD skin tests (TST) have any influence on the diagnostic ability of these ex-vivo $IFN-{\gamma}$ assays. Methods : Forty-six 15 year-old students who did not appear to be infected with Mycobacterium tuberculosis were enrolled in this study. The peripheral blood was collected and used for two $IFN-{\gamma}$ assays. The $IFN-{\gamma}$ assays and TST were performed at the baseline ($1^{st}$). The TST was repeated two months later ($2^{nd}$), and the $IFN-{\gamma}$ assays were repeated two ($2^{nd}$) and four months ($3^{rd}$) later only in those subjects who had negative results at the baseline in both the $IFN-{\gamma}$ assays and TST. An induration size > 10 mm was considered to be positive in the TST. Results : The mean TST value was $3.1{\pm}5.4mm$ (range: 0-20). Of the 46 subjects examined, 13 subjects (28.3%) showed positive results in the two-step TST. Nine (19.6%) were SPOT-positive and only one (2.2%) was QFT-positive. The $2^{nd}$ and $3^{rd}$ QFT were carried out in 23 and 25 all-negative subjects, respectively, and all showed negative results. The $2^{nd}$ SPOT was performed in 23 subjects and only one (4.3%) showed a weak-positive result. Conclusion : Even though there were some discrepancies in the results of the two ex-vivo $IFN-{\gamma}$ assays, it appears that their results were not influenced by a previous TST carried out in two or four months earlier.

• Progress in Medical Physics
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• v.12 no.2
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• pp.161-169
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• 2001

For the head and neck radiotherapy, the technique of half beam using independent collimator is very useful to avoid overlapping of fields particularly when the lateral neck fields are placed adjacent to anterior supraclavicular field. Also abutting photon field with electron field is frequently used for the irradiation of posterior neck when tolerable dose on spinal cord has been reached. Using 6 MV X-ray and 9 MeV electron beams of Clinac1800(Varian, USA) linear accelerator, we performed film dosimetry by the X-OMAT V film of Kodak in solid water phantom and the dose distribution at beam center of 2 half beams further examined according to depths(0 cm, 1.5 cm, 3 cm, 5 cm) for single anterior half beam and anterior/posterior half beam. The dose distribution to the junction line between photon and electron fields was also measured. For the single anterior half beam, the absorption doses at 0.3 cm, 0.5 cm and 1 cm distances from beam center were 88%, 93% and 95% of open beam, respectively. In the anterior/posterior half beams, the absorption doses at 0.3 cm, 0.5 cm and 1 cm distances from beam center were 92%, 93% and 95% of open beam, respectively At the junction line between photon and electron fields, hot spot was developed on the side of the photon field and a cold spot was developed on that of the electron field. The hot spot in the photon side was developed at depth 1.5 cm with 7 mm width. The maximum dose of hot spot was increased to 6% of reference doses in the photon field. The cold spot in the electron side was developed at all measured depths(0.5 cm-3 cm) with 1-12.5 mm widths. The decreased dose in the cold spot was 4.5-30% of reference dose in the electron field. With above results, we concluded that when using electron beam or independent jaw for head and neck radiotherapy, the hot and cold dose area should be considered as critical point.