• Korean Journal of Food Science and Technology
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• v.33 no.4
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• pp.479-485
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• 2001

A study of the levels of phthalate and adipate esters, which are suspected as endocrine disruptors, in food packaging wraps and packaged foods were carried out. Among 11 wrap samples, 8 household wraps purchased at retail markets were polyvinyl chloride(PVC) and polyethylene(PE), while 3 commercial wraps at wholesale markets were PVC. All of 51 selected food samples, such as 12 samples of vegetable, 11 samples of fruit, 6 samples of bread and rice cake, 4 samples of meat and poultry, 4 samples of fish and 14 samples of side dish, packaged with commercial PVC wraps containing adipate esters were purchased at retail markets. The level of di-(2-ethylhexyl) adipate(DEHA) and diisononyl adipate(DINA) was from 2.2 to 17.9% and from 4.2 to 22.3% in household PVC wraps, respectively. In the commercial PVC wraps, the level of DEHA showed from 18.3 to 22.5%, while other phthalate esters were not detected. The phthalate and adipate esters were not detected in PE wraps. The level of DEHA in packaged foods, such as vegetable, fruit, bread and rice cake, meat and poultry, fish and side dish, were determined up to $8.2\;{\mu}g/cm^2,\;17.4\;{\mu}g/cm^2,\;31.0{\mu}g/cm^2,\;8.3\;{\mu}g/cm^2,\;2.1\;{\mu}g/cm^2$ and $92.3\;{\mu}g/cm^2$, respectively. The results suggested that migration levels of DEHA in foods were closely related to the fat content, wrapping condition of food and stroage time and temperature.

• Korean Security Journal
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• no.30
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• pp.85-115
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• 2012

The private security industry has expanded in proportion to economic developments throughout the world, largely because the existing security services provided by the government do not satisfy demands of various economic entities and people in the society for better security service. Therefore, it would not be unfair to say that security services by private sectors are decided by its quality, price, and customers' needs. A refined management system, however, is essential to assess qualification of security companies and their service quality, given the nature of public goods of security service. Despite the steady growth of private security industry in Korea, however, it has been continuously criticized that its security management system for better qualification of security guards, training, and private security companies have not been fully updated enough to guarantee good quality. This paper aims to gain insights to effective policy formation in the Korean private security industry, through reviewing the licensing system of private security guards and the Approved Contractor Scheme (hereinafter the ACS) in the UK- that has on one hand systematically regulated private security industry, but on other hand has enforced public-private cooperation by laying significant stress on autonomy of private security companies. The distinctive characteristic of the UK policy for the private security is that the Security Industry Authority (hereinafter the SIA), an independent authority, is leading development of the private security industry of the UK through specialized private security regulation and enhanced service quality. In addition, the UK is developing quality of security service with transparent financial management and recruitment of good quality security guards by adopting not only substantially specified regulations and standards, but the voluntary ACS system. Moreover, the SIA analyzes customers' demands for security service specializing the policy for private security through conducting a variety of surveys. With the analysis of the UK private security system, this paper suggests that the Korean government change from a non-specialized private security regulation system by the National Police Agency to an independently specialized private security authority like the SIA and adopt the compulsory licensing and the ACS system of the UK.

• Korean Journal of Veterinary Research
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• v.41 no.4
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• pp.571-578
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• 2001

To evaluate if the apoptotic fragment assay could be used to estimate the dose prediction after radiation exposure, we examined apoptotic mouse crypt cells per 1,000 cells after whole body $^{60}Co$ $\gamma$-rays and 50MeV ($p{\rightarrow}Be^+$) cyclotron fast neutron irradiation in the range of 0.25 to 1 Gy, respectively. The incidence of apoptotic cell death rose steeply at very low doses up to 1 Gy, and radiation at all doses tigger rapid changes in crypt cells in stem cell region. These data suggest that apoptosis may play an important role in homeostasis of damaged radiosensitive target organ by removing damaged cells. The curve of dose-effect relationship for the data of apoptotic fragments was obtained by the linear-quadratic model $y=0.18+(9.728{\pm}0.887)D+(-4.727{\pm}1.033)D^2$ ($r^2=0.984$) after $\gamma$-rays irradiation, while $y=0.18+(5.125{\pm}0.601)D+(-2.652{\pm}0.7000)D^2$ ($r^2=0.970$) after neutrons in mice. The dose-response curves were linear-quadratic, and a significant dose-response relationship was found between the frequency of apoptotic cell and dose. These data show a trend towards increase of the numbers of apoptotic crypt cells with increasing dose. Both the time course and the radiation dose-response curve for high and low linear energy transfer (LET) radiation modalities were similar. The relative biological effectiveness (RBE) value for crypt cells was 2.072. In addition, there were significant peaks on apoptosis induction at 4 and 6h after irradiation, and the morpholoigcal findings of the irradiated groups were typical apoptotic fragments in crypt cells that were hardly observed in the control group. Thus, apoptosis in crypt cells could be a useful in vivo model for studying radio-protective drug sensitivity or screening test, microdosimetric indicator and radiation-induced target organ injury. Since the apoptotic fragment assay is simple, rapid and reproducible in the range of 0.25 to 1 Gy, it will also be a good tool for evaluating the dose response of radiation-induced organ damage in vivo and provide a potentially valuable biodosimetry for the early dose prediction after accidental exposure.

• Journal of Oral Medicine and Pain
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• v.35 no.4
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• pp.245-258
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• 2010

Smoking has been identified not as a major risk factor for circulatory and respiratory diseases but also as causes of various oral diseases. A number of clinical studies and regional health surveys have found an association between smoking and poor oral health status and between smoking and prognosis of dental treatments. However, there is few studies about status of smoking cessation treatment and policies in dentistry in Korea. The purpose of this study was to investigate the smoking patterns of outpatients and outcomes of short-term smoking cessation treatment in dental hospitals in Korea and, subsequently, to seek further smoking cessation services in dentistry. This study was sponsored by Korean Dental Association (KDA) and department of culture and welfare. 825 dental patients were voluntarily participated in a 4-week smoking cessation program with nicotine patch and 297 participants of them completed on smoking-related questionnaires. All participants were recruited from outpatients of 11 dental university hospitals (primarily in the department of oral medicine, oral surgery and periodontology) in Korea during 3-month period from October 2009 to January 2010. The Questionnaires included demographics, duration of smoking, heavy smoking index (HSI), number of thinking of quit smoking, duration of stop smoking and reasons to smoking, awareness of smoking effects on oral health, and their success rate after 4 weeks of nicotine patch program was investigated. The statistical analysis was carried by SPSS version 18.0 program and Chi-square test. According to the results of this study, male in their 30s to 50s were the most prevalent of all the participants and duration of smoking increased with age. Attempt rate to quit smoking (Quit smoking) was the highest in 30s and 40s with duration of quit smoking ranging 1 to 3 months. Emotional stresswas the most frequently reported reason for smoking, followed by habit and pleasure in order. All age group showed high HIS over 71% and awareness of smoking effects on oral diseases such as oral soft tissue diseases, periodontal diseases and dental caries was found relatively high (50~60%) Periodontal implant was the main reason for participation in the smoking cessation services in dental clinics and the success rate of, 4-week nicotine patch program of all the participants was 29.4%, extremely low compared to that of medical clinics. Systemic education for dentists to be able to provide interventions to quit smoking including counseling with the 5As'and development of available measures for smokers is needed as considered that the low success rate of the smoking cessation services in dentistry could be explained mainly by lack of dentists' strategies, experience and attention. Awareness and attention of dentists should be emphasized and their participation be encouraged by long-term, multidisciplinary policies such as establishment of insurance fee, which would made a considerable progress in preventing smoking-related oral diseases and promoting public oral health.

• Korean Journal of Environmental Agriculture
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• v.14 no.3
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• pp.263-271
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• 1995

Chemical assessment of soil pollution with heavy metals was made by analyzing the changes in pH, ionic strength, cationic concentration and chemical species in the soil solution. Saturated pastes of the unpolluted soils were made by adding solutions containing Cu or Cd and the final Cu or Cd concentrations were in the range of 0 to 400 mg/kg. After equilibrating for 24 hours at $25^{\circ}C$, the soil solution was extracted from the saturated pastes by the vacuum extraction method and analyzed for pH, electrical conductivity, Cu, Cd, cations and inorganic ligands. Chemical species in soil solution were calculated by the GEOCHEM-PC program employing the input variables of pH, ionic strength(${\mu}$), molar concentrations of cations and ligands. Increasing Cu or Cd additions lowered pH of the soil solution but increased concentrations of Ca, Mg and K resulting in increases of ${\mu}$ of the soil solution. Effects of Cu on lowering pH and increasing ${\mu}$ were greater than those of Cd. Concentrations of Cu or Cd in soil solution were relatively very low as compared to those of additions, but increased linearly with increasing additions representing that concentrations of Cu were higher than those of Cd. At 400 mg/kg additions, concentrations of Cu were in the range of 0.51 to 11.70 mg/L but those of Cd were 34.4 to 88.5 mg/L. Major species of Ca, Mg and K were free ions and these species were equivalent to greater than 95 molar % of the existing respective molar concentrations. These cationic species were not changed by Cu or Cd additions. Major species of Cu in lower pH soils such as SiCL and SL were free $Cu^{2+}$ (>95 molar %), but those in LS having a higher pH were free $Cu^{2-}$ and Cu-hydroxide complex. At 100 mg Cu/kg treatment, $Cu^{2+}$ and Cu-hydroxide complex were equivalent to 73 and 22.4 molar %, respectively. These respective percentages were decreased and increased correspondingly with increasing Cu treatments. Major species of Cd in soil solution were free $Cd^{2+}$ and Cd-chloride complex, representing 79 to 85 molar % for $Cd^{2+}$ and 13 to 20% for Cd-chloride complex at 10 mg Cd/kg treatment. With increasing Cd additions to 400 mg/kg, $Cd^{2+}$ species decreased to $40{\sim}47%$ but Cd-chloride complexes increased to $53{\sim}60$ molar %. These results demonstrated that soil contamination with heavy metals caused an adverse effect on the plant nutritional aspects of soil solution by lowering pH, increasing cations temporarily, and increasing free metal concentrations and species enough to be phytotoxic.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.2
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• pp.186-192
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• 1997

Increased activities of phase 2 enzymes including quinone reductase(QR) have been reported to be associated with protection of animals from neoplastic, mutagenic, and other toxic effects of many carcinogens. In previous study, we found that methanol extract of roasted and defatted perilla meal induced the activity of quinone reductase, an anticarcinogenic marker enzyme, in murine hepalc1c7 cells. Current study showed that unroasted perilla had a limited QR-inducing activity, suggesting that roasting cause the generation of active component(s). Thus we hypothesized that QR inducer in perilla might be covalently linked to sugar moiety and released during roasting process. Methanol extract of defatted raw perilla was subject to acid treatment in order to hydrolyze the potential sugar moiety. Prolonged hydrolysis of methanol extract of defatted raw perilla at $98{\sim}100^{\circ}C$ increased the ability to induce cytosolic QR activity of hepalclc7 cells. Furthermore roasting at 180 and $200^{\circ}C$ resulted in significant induction of QR activity. The result strongly support the idea that QR inducer(s) is present in bound form in raw perilla and released during roasting. Cellular QR activity was induced proportionately with the increase of concentration of methanol extract of roasted perilla. The induction of QR by defatted perilla was also examined in the cytosols of liver, small intestine, stomach, lung and kidney of male ICR mice. Induction patterns showed specificity with respect to target tissue and roasting of perilla. Unroasted perilla meal (defatted) significantly induced QR in liver and lung, while roasted perilla meal induced QR in liver and stomach. The observation that raw perilla showed similar QR induction patterns to roasted perilla is consistent with our proposal that QR inducer(s) is present in bound form and released by physical and chemical treatments as digestive or microbial enzymes could release the inducers from inactive glycoside forms in gastrointestinal tract of mice. In conclusion, perilla could exert protective effect against chemically induced carcinogenesis by inducing phase 2 enzymes in biological systems regardless of chemical and physical process such as roasting.

• Journal of the Korean earth science society
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• v.21 no.3
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• pp.349-358
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• 2000

Compressional and shear wave velocities (Vp and Vs) and densities have been measured for serpentinite, amphibolite, amphibole and biotite schist, and gneiss from western part of Chungnam Province at room temperature. Ranges of the density are 2.6${\sim}$2.86g/cm$^3$ for serpentinite, 2.25${\sim}$2.81g/cm$^3$ for talc, and 2.74${\sim}$3.07g/cm$^3$ for metamorphic rocks. Of these rocks, talc shows wider ranges than serpentinite and amphibolites due to its metamorphic process from serpentinite. Values of Vp and Vs are 5719${\sim}$6062m/s and 2898${\sim}$3351m/s for serpentinites, 4019${\sim}$5478m/s and 2241/${\sim}$2976m/s for talc, 5375${\sim}$6372m/s and 3042${\sim}$3625m/s for amphibolite, 5290${\sim}$5499m/s and 2968${\sim}$3137m/s for schist, and 4788m/s and 2804m/s for gneiss, respectively. Velocity of P wave increases 1.47 times faster than S wave with increase of density. The results of seismic velocity measurement show anisotropy, higher velocity across than along the schistocity of rocks, especially in metamorphic rocks. This fact indicates that there were regional metamorphism related with tectonic forces. Values of seismic velocity increase with increasing pressure from 20 MPa to 70 MPa, especially in metamorphic rocks. Overall recalculated Vp and Vs values suggest that the serpentinite indicates for upper mantle in the respects of seismic characteristics, in spite of high degree of serpentinization. In addition, those of the amphibolite do for low crust, and gneiss and schist for upper crust.

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.120-130
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• 1996

Crisphead lettuce(Lactuca sativa L.) was grown in NFT to investigate the effects of NO$_3$-N and NH$_4$-N ratio in nutrient solution and elevated $CO_2$ treatment in the crisphead lettuce growth. This experiment has been conducted under three different ratios of NO$_3$-N:NH$_4$-N(100:0, 75:25, 50:50) with two $CO_2$ concentration (control, 1500ppm ). The results are as follows; 1. In the case of not controlling pH and EC in nutrient solution, pH was gradually increased in NO$_3$-N:NH$_4$-N=100:0 treatment but rapidly decreased in the nutrient solution 2. Daily changes of NO$_3$-N and NH$_4$-N were observed without controlling the nutrient solution. In the treatments of NO$_3$-N:NH$_4$-N ratios were 75:25 and 50:50, NO$_3$-N absorption rates were 27.7% and 26.1%, while NH$_4$-N absorption rates were 87.9% and 71.2%, respectively. 3. There was little differences in total nitrogen of leaves. However phosphorus, potassium, calcium and magnesium contents were highly shown in the treatment of $CO_2$ 1500ppm and 100:0 ratio of NO$_3$-N:NH$_4$-N. 4. Higher $CO_2$ assimilation rate was shown in plants grown under $CO_2$ 1500ppm and 100:0 ratio of NO$_3$-N:NH$_4$-N. It dropped significantly with the increase of NH$_4$- N rates in nutrient solution. 5. Fresh weight, leaf number, root length and root weight of crisphead lettuce were far better in the treatment of $CO_2$ 1500ppm and 100:0 ratio of NO$_3$-N:NH$_4$-N. Growth differences by $CO_2$ elevation were not shown in other NO$_3$-N:NH$_4$-N treatments. 6. The highest nitrate contents of leaves were shown in NO$_3$-N single treatment but shown the lowest vitamin C contents. Nitrate contents of leaves were decreased by $CO_2$ but the effect was slight treatment.

• Progress in Medical Physics
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• v.23 no.3
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• pp.145-153
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• 2012

In this study, we quantify the residual motion artifact in 4D-CT scan using the dynamic lung phantom which could simulate respiratory target motion and suggest a simple one-dimension theoretical model to explain and characterize the source of motion artifacts in 4DCT scanning. We set-up regular 1D sine motion and adjusted three level of amplitude (10, 20, 30 mm) with fixed period (4s). The 4DCT scans are acquired in helical mode and phase information provided by the belt type respiratory monitoring system. The images were sorted into ten phase bins ranging from 0% to 90%. The reconstructed images were subsequently imported into the Treatment Planning System (CorePLAN, SC&J) for target delineation using a fixed contour window and dimensions of the three targets are measured along the direction of motion. Target dimension of each phase image have same changing trend. The error is minimum at 50% phase in all case (10, 20, 30 mm) and we found that ${\Delta}S$ (target dimension change) of 10, 20 and 30 mm amplitude were 0 (0%), 0.1 (5%), 0.1 (5%) cm respectively compare to the static image of target diameter (2 cm). while the error is maximum at 30% and 80% phase ${\Delta}S$ of 10, 20 and 30 mm amplitude were 0.2 (10%), 0.7 (35%), 0.9 (45%) cm respectively. Based on these result, we try to analysis the residual motion artifact in 4D-CT scan using a simple one-dimension theoretical model and also we developed a simulation program. Our results explain the effect of residual motion on each phase target displacement and also shown that residual motion artifact was affected that the target velocity at each phase. In this study, we focus on provides a more intuitive understanding about the residual motion artifact and try to explain the relationship motion parameters of the scanner, treatment couch and tumor. In conclusion, our results could help to decide the appropriate reconstruction phase and CT parameters which reduce the residual motion artifact in 4DCT.

• Journal of Preventive Medicine and Public Health
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• v.29 no.3 s.54
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• pp.669-678
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• 1996

Helicobacter pylori is now recognized as causative agent of chronic gastritis and peptic ulcer, and strongly associated with development of gastric carcinoma. With development of sensitive and specific serologic tests to identify individuals infected with Helicobacter pylori, the epidemiologic study of this diseases has been investigated. But it's transmission route is not established, yet. The purpose of this study is to measure the prevalence of Helicobacter pylori infection in healthy children and young adults and to evaluate related factors for Helicobacter pylori infection in Korea. The seroprevalence of Ig G antibodies to Helicobacter pylori was determined using a Enzyme Linked Immunosorbent Assay and we obtained the information, such as demographic characteristics, monthly household income, numbers of family members in the house, numbers of persons using same room, type of house, and type of drinking water through the questionnaire survey. The observed overall seropositivity rate was 25.7%. The rate is increased progressively from 5.8% in the age group $1\sim3$ years to 44.4% in the age group $20\sim29$years($\chi^2$ for trend, p<0.001). Especially, the rate increased steeply from 6.5% in the age group $4\sim6$ years to 20.8% in the age group $7\sim9$ years, and this suggested that elementary school age was the major acquisition time of Helicobacter pylori infection. In multivariate logistic regression model, age, numbers of family members in the house, and type of house was statistically significant variables for Helicobacter pylori infection. Each odds ratio(93% CI) were as follows; base to age group $1\sim9$ years, age group $10\sim19$ years $3.6(2.0\sim6.4)$, age group $20\sim29$ years $7.3(4.1\sim13.1)$ and base to group of $1\sim3$ family members, group of $4\sim5$ family members $2.1(1.1\sim4.0)$, group of 6 or more family members $2.7(1.3\sim5.4)$ and base to apartment, single and multihouse $1.9(1.1\sim3.5)$. Sex, monthly household income, numbers of persons using same room, and type of drinking water was not statistically significant for Helicobacter pylori infection.