• Korean Journal of Environment and Ecology
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• v.32 no.5
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• pp.486-496
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• 2018

In this study, we have selected Larix kaempferi as a study area in Woraksan National Park for understanding the ion index according to the difference of topography in national parks. We measured the weather and ion at two fixed points, ridge and valley, where the Larix kaempferi dominates in the same ecological structure in Woraksan National Park. The weather measurement results showed the average, maximum, and minimum temperatures of $28.22^{\circ}C$, $29.9^{\circ}C$, and $26.4^{\circ}C$, respectively at the ridge. The average, maximum, and minimum temperatures at the valley were $27.08^{\circ}C$, $27.8^{\circ}C$, and $25.5^{\circ}C$, respectively. The average, maximum, and minimum relatively humidities at the ridge were 67.02%, 75.25%, and 61.95%, respectively. he average, maximum, and minimum relatively humidities at the valley were 69.74%, 76.8%, and 63.75%, respectively. The average, maximum, and minimum amounts of positive ions generated in the ridge was $698.40{\pm}59.80ea/cm^3$, $885.88ea/cm^3$, and $597.88ea/cm^3$, respectively. The average, maximum, and minimum amounts of negative ions generated in the ridge were $736.07{\pm}83.89ea/cm^3$, $934.53ea/cm^3$, and $599.32ea/cm^3$, respectively. The ion index is calculated to be 1.06. The average, maximum, and minimum amounts of positive ions generated in the valley were $1,732.49{\pm}354.08ea/cm^3$, $2,652.10ea/cm^3$, and $1,110.92ea/cm^3$, respectively. The average, maximum, and minimum amounts of negative ions generated in the valley were $1,990.47{\pm}433.57ea/cm^3$, $3,126.75ea/cm^3$, and the minimum value was $1,352.17ea/cm^3$. The ion index is calculated to be 1.16. The difference in the amount of negative ions generated in ridge and valley was $1089.26ea/cm^3$, and the difference of the calculated ion index between the ridge portion and the valley portion was 0.10. The results of this study were provided as the reference weather data of national parks for health management.

• Journal of Periodontal and Implant Science
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• v.33 no.4
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• pp.625-641
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• 2003

Background: This study presents a biomechanical and histometric comparison of bone response to implants with various area of hydroxyapatite(HA) coating. Methods: The implants were placed in the tibia of 10 rabbits weighing 2.5-3.5kg. The control group had a machined surface, the experimental group 1 had 50${\mu}m$ thick HA coated in a band form, and the experimental group 2 had 50${\mu}m$ thick HA coated on the entire surface. 8 weeks after implantation, the animals were sacrificed. Removal torque was measured and histologic preparation was also performed for histologic and histometric analysis. Bone to implant contact as well as percentage of bone area inside threads were measured. ANOVA post hoc, and t-test were used for statistical analysis with p-value p<0.05. Results: 1. The removal torques were 9.36${\pm}$5.64 Ncm, 48.40 ${\pm}$ 16.66 Ncm, and 82.37${\pm}$22.56 Ncm for the control, exp. 1, and exp. 2 group respectively. Statistically significant difference were found among all the groups(p<0.05). 2. Bone to implant contact in the cortical bone were 38.94${\pm}$10.9 %, 66.90${\pm}$14.1 %, 73.00${\pm}$19.4 %, in the marrow bone, 8.30${\pm}$5.4%, 14.59${\pm}$5.9%, 18.54${\pm}$11.8%, and in total, 22.40${\pm}$10.1%, 31,17${\pm}$7.5%, 41.41${\pm}$12.2% for the control, exp. 1, and exp. 2 group respectively . In the cortical bone, exp. 1, and exp. 2 group showed statistically significantly higher contact compared to control group. Total contact and in the marrow bone, only exp. 2 group showed statistically significantly higher contact compared to control group(p<0.05). In all the groups significantly higher contact were observed in the cortical bone compared to the marrow bone(p<0.05). 3. Percentage of bone area inside threads in the cortical bone were 55.68${\pm}$7.25%, 55.19${\pm}$13.19%, 57.04${\pm}$13.33%, in the marrow bone, 12.34${\pm}$14.61%, 17.56${\pm}$20.04%, 20.26${\pm}$12.83%, and in total, 30.30${\pm}$12.46%, 31.57 ${\pm}$15.15%, 34.25${\pm}$12.56% for the control, exp.1, and exp. 2 group respectively. There was no statistical difference among the groups. In all the groups significantly higher bone area were observed in the cortical bone compared to the marrow bone(p<0.05)

• Journal of Environmental Policy
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• v.7 no.2
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• pp.67-90
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• 2008

The purpose of this study is to develop indoor air quality management strategies regarding indoor air pollutants while considering various factors affecting indoor pollutants concentration. The Integrated Indoor Air Quality model(IIAQ) developed by Seoul National University is used for this study. The IIAQ model is a tool that can provide an integrated view to indoor environmental pollution by simulating suggested scenarios. The results of the modeling are used to assess health risk. The concentrations that are used for the risk characterization are weighted concentrations based on the period of time in each place and existing Indoor Air Quality(IAQ) standards. The estimated concentration of toluene and formaldehyde for 10 years through the IIAQ model was 207.3 $ug/m^3$ and 36.4 $ug/m^3$ in indoors, and 55.9 $ug/m^3$ and 8.62 $ug/m^3$ in outdoors. These concentrations are lower than the existing IAQ standards. The estimated carcinogenic risk of formaldehyde is up to 1.05E-03 for the adult male group and exceeds 1E-06 for all receptor groups. This value means that cancer could affect one person out of 1000. The estimated non-carcinogenic risk of toluene was lower than 1, which means that there was no serious non- carcinogenic risk. The result of modeling shows that using low emitting indoor sources is the most effective strategy for both formaldehyde and toluene. This risk assessment suggests that the total exposure levels of existing IAQ standards may cause serious carcinogenic risk. In order to avoid uncontrolled risk, it is suggested that the current IAQ standards should be adjusted by taking into account the total amount of exposure from all exposure pathways from indoor and outdoor sources.

• Korea Journal of Hospital Management
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• v.9 no.1
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• pp.66-94
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• 2004

The objective of this study is to examine how to maximize the efficiency of hospital management by minimizing the unit cost of hospital operation. For this purpose, this paper proposes to develop a model of the profit maximization based on the cost minimization dictum using the statistical tools of arriving at the maximum likelihood values. The preliminary survey data are collected from the annual statistics and their analyses published by Korea Health Industry Development Institute and Korean Hospital Association. The maximum likelihood value statistical analyses are conducted from the information on the cost (function) of each of 36 hospitals selected by the random stratified sampling method according to the size and location (urban or rural) of hospitals. We believe that, although the size of sample is relatively small, because of the sampling method used and the high response rate, the power of estimation of the results of the statistical analyses of the sample hospitals is acceptable. The conceptual framework of analyses is adopted from the various models of the determinants of hospital costs used by the previous studies. According to this framework, the study postulates that the unit cost of hospital operation is determined by the size, scope of service, technology (production function) as measured by capacity utilization, labor capital ratio and labor input-mix variables, and by exogeneous variables. The variables to represent the above cost determinants are selected by using the step-wise regression so that only the statistically significant variables may be utilized in analyzing how these variables impact on the hospital unit cost. The results of the analyses show that the models of hospital cost determinants adopted are well chosen. The various models analyzed have the (goodness of fit) overall determination (R2) which all turned out to be significant, regardless of the variables put in to represent the cost determinants. Specifically, the size and scope of service, no matter how it is measured, i. e., number of admissions per bed, number of ambulatory visits per bed, adjusted inpatient days and adjusted outpatients, have overall effects of reducing the hospital unit costs as measured by the cost per admission, per inpatient day, or office visit implying the existence of the economy of scale in the hospital operation. Thirdly, the technology used in operating a hospital has turned out to have its ramifications on the hospital unit cost similar to those postulated in the static theory of the firm. For example, the capacity utilization as represented by the inpatient days per employee tuned out to have statistically significant negative impacts on the unit cost of hospital operation, while payroll expenses per inpatient cost has a positive effect. The input-mix of hospital operation, as represented by the ratio of the number of doctor, nurse or medical staff per general employee, supports the known thesis that the specialized manpower costs more than the general employees. The labor/capital ratio as represented by the employees per 100 beds is shown to have a positive effect on the cost as expected. As for the exogeneous variable's impacts on the cost, when this variable is represented by the percent of urban 100 population at the location where the hospital is located, the regression analysis shows that the hospitals located in the urban area have a higher cost than those in the rural area. Finally, the case study of the sample hospitals offers a specific information to hospital administrators about how they share in terms of the cost they are incurring in comparison to other hospitals. For example, if his/her hospital is of small size and located in a city, he/she can compare the various costs of his/her hospital operation with those of other similar hospitals. Therefore, he/she may be able to find the reasons why the cost of his/her hospital operation has a higher or lower cost than other similar hospitals in what factors of the hospital cost determinants.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.415-423
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• 1995

This study was conducted to analyze the chemical composition, nutritional contents, and saponin in the xylem sap of Acer mono Max. From Feb 25 to Mar 4, 1994, spring sap was collected by making holes with 1.7cm diameter on the trunk of trees in Mt. Baekwoon and Mt. Jiri. Sugars were quantified by HPIC, amino acids by amino acid analyzer, saponins by TLC, HPLC, and $^1H$ & $^{13}C$ NMR. Major component of the sap was sucrose at a concentration range of 0.68 to 2.01%. Following minor components were found: glucose at 0.03-0.11%, and fructose at 0.01-0.03% as sugars, lipid at 0.03%, threonine at 0.152%, lysine at 0.038%, arginine at 0.068% as amino acids, ash at 0.1%, Ca at 175ppm, Fe at 2ppm, P at 19ppm, K at 16ppm, Na at 31ppm as minerals, vitamin $B_1$ at 0.6ppm, vit. $B_2$ at 0.1ppm, and vit. C at 19ppm. A trace of phenolic compounds was found by TLC, while saponin commonly reported in high-quality ginseng roots was not found in maple sap. It is concluded that sap of Acer mono contains a good variety of natural compounds such as sugars, amino acids, Ca, Fe, and vitamins to serve as an excellent source of very natural and health-promoting drink.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.3
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• pp.271-278
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• 2017

This study was performed to evaluate the cytotoxicity of aluminum chloride ($AlCl_3$), and the protective effect of Lonicerae flos (LF) extract on $AlCl_3-induced$ cytotoxicity in the cultured C6 glioma cells. Here, the cell viability and antioxidative effects, such as DPPH-radical scavenging activity, superoxide anion scavenging activity, and lipid peroxidation (LP), were assessed. $AlCl_3$ significantly decreased the cell viability in a dose-dependent manner; the $XTT_{50}$ value was measured at $128.8{\mu}M$ of $AlCl_3$. The cytotoxicity of $AlCl_3$ was determined as highly toxic the y Borenfreund and Puerner's toxic criteria. The butylated hydroxytoluene (BHT) and antioxidant both significantly increased the cell viability, which was damaged by $AlCl_3-induced$ cytotoxicity in these cultures. In the protective effect of LF extract on $AlCl_3-induced$ cytotoxicity, the LF extract significantly increased the superoxide anion scavenging activity and inhibitory activity of LP, as well as the DPPH-radical scavenging activity. From these results, it is suggested that the oxidative stress may have been involved in the cytotoxicity of $AlCl_3$, and LP extract effectively protected $AlCl_3-induced$ cytotoxicity through the antioxidative effects. Conclusively, the natural resources, like LP extract, may be a putative therapeutic agent for the treatment of dementia induced by allergen like aluminum correlated with the oxidative stress.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.2
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• pp.39-47
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• 2014

Purpose As breast cancer patients continue to increase every year, cases of BSGI are on the rise with a heavier reliance on it. However, BSGI protocol in hospitals was not studied enough despite it was covered by hospital's condition and recommendation of manufacturers. The objective of the study was an examination of methods to be applicable to BSGI protocols, putting the self-development phantom to use in quality assessment of the images. Materials and Methods Dilon 6800 (Dilon Technologies Inc, Newport News, USA) was used in the study and five different sizes of sphere were distinctively produced in the phantom. The study used $^{99m}TcO_4$. The cases were classified in to three categories that background radioactivity to region of interest as ratio of 2: 4: 8, They were acquired images for 5, 7, 10mins. The acquired image was set region of interest according to the size of sphere, and We analyzed quantitative and qualitative analysis. The acquired data statistically analyzed with SPSS ver.18.0. Results As the result of quantitative and qualitative analysis, count rate of each sphere in accordance with difference of injection dose showed that higher count rate as injection dose and sphere size increased (P<0.005). Count rate of each sphere in accordance with difference of acquisition time showed that higher count rate as acquisition time and sphere size increased (P<0.005). Contrast noise ratio of each sphere in accordance with difference of injection dose showed that higher contrast noise ratio as injection dose increased. Particularly, Contrast noise ratio of eight times ratio images was the highest among. Contrast noise ratio of each sphere in accordance with difference of acquisition time showed that higher contrast noise ratio as acquisition time increased. And, Contrast noise ratio of seven minute image was the highest among (P<0.005). Conclusion There was significant change of Contrast noise ratio through quantitative and qualitative analysis. Moreover, We found usefulness of phantom. If Institutions identified image through the phantom study and they made BSGI protocol, We expected to help the improvement of diagnostic value of the images.

• Journal of radiological science and technology
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• v.31 no.1
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• pp.11-16
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• 2008

Purpose : The aim of this study was to predict radiation dose at 1 meter with BMI(body mass index) in thyroid cancer patients treated with radio-iodine and provide the efficient guideline in the management of patients. Methods : 140 patients from thyroidectomy for thyroid cancer were enrolled. All subjects under went 150 mCi radio-iodine therapy and performed whole body scan 1 week later. BMI(weight divided by square of height) was calculated to evaluate the amount of fatty tissue indirectly. The radiation dose at 1 meter was measured initially and on 2nd days. the relation of values with BMI were analyzed statically. As for the method of statistical analysis, using Med calc Version 9,2,2,0 Program. Results : (1) The initial effective dose was inversely correlated with the BMI. Significance level was 0.0004. (2) We obtained the following formula from the data of initial effective dose and BMI: Y = -30.91X + 350.4(${\mu}Sv/h$)(Y: initial radiation dose, x: Group). (3) After 21.55 hours, than radiation dose was less than those recommended by ICRP or NRC in 53% of the population. Conclusion : Using BMI, the initial radiation dose and 2nd days dose can be predicted in thyroid cancer patients before radio-iodine therapy. It may be used for predicting the time of discharge and control the isolation room. We were able to predict the radiation exposure after discharge using this calculated value.

• Journal of Nutrition and Health
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• v.18 no.4
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• pp.301-311
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• 1985

Even though the anticarcinogenic effect of dietary factors especially beta - carotene has been reported by various investigators, the mechanism of the action of ${\beta}-carotene$ has not yet been identified. We carried out the present study to determine the possibilities of relative cancer risk related to dietary intake of vitamin A ( both ${\beta}-carotene$ and retinol ) and blood levels of vitamin A among Koreans. The subjects were divided into two groups; cancer patients and controls. Blood levels for ${\beta}-carotene$ and retinol were analyzed by alumina column chromatography and colorimetry. Dietary intake was examined by food profile and convenient method for evaluating nutritional status through recalling 10 years of food habits. The results obtained are as follows : 1 ) Calorie, protein, fat, and carbohydrate intakes of cancer patient were lower than those of control. Calorie and carbohydrate intakes showed no significant difference but protein and fat intakes were significantly lower in cancer patients. According to cancer sites, in stomach cancer only fat intake was significantly lower than that of control. In lung and larynx cancer calorie, protein, fat and carbohydrate intakes showed similar trend as in control. 2 ) Vitamin A intake of cancer patient was significantly lower than that of control. It was estimated that 83.6% of total Vitamin A intake were provided by ${\beta}-carotene$ for control and cancer patient respectively. 3 ) The mean intake of dietary ${\beta}-carotene$ in cancer patient was significantly lower than that in control ( $7002\;\mu}g/day$ versus $10326\;{\mu}g/day$ ) According to cancer sites in mean intake of dietary ${\beta}-carotene$ was significantly lower in all but stomach cancer compared with that of control. Lung and larynx cancer showed lowest ${\beta}-carotene$ intake with mean value of $5855{\mu}g/day$ and $5492{\mu}g/day$ respectively. 4 ) The mean intake of dietary retinol in cancer patient was significantly lower than that in control ( $245{\mu}g/day$ versus $338{\mu}g/day$ ), but the difference was not significant. 5 ) The relative risk of all cancers in the first (lowest) to the forth quartile level of ${\beta}-carotene$ consumption such as $0-5999{\mu}g/day$. $6000-8999{\mu}g/day$, $9000-11999{\mu}g/day$/ day and $12000-20000{\mu}g/day$ was 85 : 1.7 : 20 : 1.0. The relative risk of all cancers in the first (lowest) to the forth quartile level of retinol consumption, such as $0-299{\mu}g/day$, $300-599{\mu}g/day$, 600-899${\mu}g/day$, and $900-1200{\mu}g/day$, was 1.14 : 067 : 0.21 : 1.0. 6 ) The various food group consumption of cancer patient were significantly lower than those of control in green leafy vegetables, fruits, sea weeds, milk and cheese and eggs. But the Kimchie consumption in cancer patient was three fold higher than that of control ( $1840\;{\mu}g/day$ versus $562\;{\mu}g/day$ ) and in the stomach cancer, Kimchie consumption was the highest, ( $1890\;{\mu}g/day$) According to cancer sites, the consumption of green leafy vegetables was significantly lower in all but stomach cancer compared to control and other vegetables showed no difference between two. In lung and larynx cancer, green leafy vegetables consumption was lowest ( $6094{\mu}g/day$ $5921{\mu}g/day$) and milk and cheese consumption was also( $5\;{\mu}g/day$ and $11{\mu}g/day$) 7 ) The recovery of ${\beta}-carotene$ from human serum by alumina column chromatography was $94.4{\pm}2.3%$. 8 ) Cancer patients showed significantly lower serum retinol ($56.4{\pm}18.1\:{\mu}g/100ml$ versus $72.2{\pm}21.8\:{\mu}g/100ml$) and ${\beta}-carotene$ ($48.9{\pm}33.8\:{\mu}g/100ml$ versus $72.2{\pm}42.6\:{\mu}g/100ml$) concentrations than in controls. 9 ) But breast cancer patients were not significantly different from controls in their serum retinol and ${\beta}-carotene$ concentrations.

• The Korean Journal of Food And Nutrition
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• v.11 no.1
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• pp.61-67
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• 1998

Effects of various jelly prepared with different concentrations of agar and sugars on overall acceptability of the peach jelly were investigated. The preparations of peach for experimental jelly were carried by the mixture of peach pulp and juice(MPJ), and the extract form peach(EP). The results were summarized as follows ; 1. The pH for MPJ and EP were 3.95 to 4/31, respectively, and the brix degree were 13.0% and 11.5%, respectively. 2. The jelly prepared with MPJ added 3% agar and 30% sugar were most effective in appearance, hardness, springiness and overall acceptability. The relation of samples(P<0.001) was found to be significant. On the other hand, the jelly prepared with EP was higher scored than that with MPJ in overall acceptability, but there was no significant differences between samples. 3. The Hunter values of L*, a* and b* were the highest in both the jelly prepared with MPJ and that with EP, added 2% agar and 10% sugar. However, the L*, a* and b* values of the jelly added MPJ were higher than those of the sample added EP. 4. Texture and color scores of both the jelly added EP became higher as the concentrations of agar and sugars increased and there was significant differences between samples. 5. The relation between springiness and overall acceptability, and L* value of the jelly added MPJ showed negative at P<0.05 and that between springiness and overall acceptability of the jelly added EP also showed negative.