• Tuberculosis and Respiratory Diseases
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• v.55 no.1
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• pp.88-97
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• 2003

Background : Although smoking is a major cause of chronic obstructive pulmonary disease (COPD), only 10-20% of cigarette smokers develop symptomatic COPD, which suggests the presence of genetic susceptibility. This genetic susceptibility to COPD might depend on variations in the activities of the enzyme that detoxify hazardous chemical products, such as microsomal epoxide hydrolase (mEPHX) and glutathione-S transferase M1 subunit (GSTM1) genes. Methods : The genotypes of 58 patients with COPD, and 79 age matched control subjects, were determined by a polymerase chain reaction, followed by restriction fragment length polymorphism (PCR-RFLP) for the mEPHX, and multiplex PCR for the GSTM1. Results : GSTM1 was deleted in 53.3% of the subjects. There was no difference in GSTM1 deletion rates between the COPD patients (32/58, 55.2%) and the control subjects (41/79, 51.9%). The combination patterns of two polymorphisms of mEPHX showed slow enzyme activity in 29(21.2%), normal in 73(53.3%) and fast in 32(23.4%). The COPD group (7/57, 12.3%) showed a significantly lower incidence of slow enzyme activity compared to the control subjects (22/77, 28.6%, p<0.05). However, when the COPD and control groups were compared with smokers only, there were no significant differences in the genotypes of GSTM1 and mEPHX. Conclusion : The genotypes of GSTM1 and mEPHX were not significant risk factors of COPD in this cohort of study.

• Tuberculosis and Respiratory Diseases
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• v.58 no.5
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• pp.490-497
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• 2005

Background : The paraoxonase enzyme plays a significant role in the detoxification of various organophosphorous compounds in mammals, and paraoxonase (PON) 1 is one of the endogenous free-radical scavenging systems in the human body. In this study, we investigated the interaction between cigarette smoking and the genetic polymorphism of PON1 with lung cancer in Korean males. Methods : Three hundred thirty five patients with lung cancer and an equal number of age-matched controls were enrolled in this study. Every subject was asked to complete a questionnaire concerning their smoking habits and alcohol drinking habits. A 5' exonuclease assay (TaqMan) was used to genotype the PON1 Q192R polymorphism. The effects of smoking habits and drinking habits, the PON1 Q192R polymorphism and their interactions were statistically analyzed. Results : Cigarette smoking and the Q/Q genotype of PON1 were significant risk factors for lung cancer. Individuals carrying the Q/Q genotype of PON1 were at a higher risk for lung cancer as compared with those individuals carrying the Q/R or R/R genotype (odds ratio, 2.84; 95% confidence interval, 1.69 - 4.79). When the groups were further stratified by the smoking status, the Q/Q PON1 was associated with lung cancer among the current or ex-smokers (odds ratio, 2.56; 95% confidence interval, 1.52 - 4.31). Current smokers or ex-smokers who had the Q/Q genotype showed an elevated risk for lung cancer (odds ratio: 15.50, 95% confidence interval: 6.76 - 35.54) as compared with the group of subjects who never smoked, and had the Q/R or R/R genotype. The odds ratios (95% confidence interval) of smokers with the PON1 Q/Q type compared to the nonsmokers with the PON1 Q/R or R/R type were 53.77 (6.55 - 441.14) for squamous cell carcinoma, 6.25 (1.38 - 28.32) for adenocarcinoma, and 59.94 (4.66 - 770.39) for small cell carcinoma, and these results were statistically significant. Conclusion : These results suggest that cigarette smoking and the PON1 Q/Q genotype are risk factors for lung cancer. The combination of cigarette smoking and the PON1 Q/Q genotype significantly increased the lung cancer risk irrespective of the histologic type of cancer.

• Korean Journal of Ecology and Environment
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• v.35 no.1 s.97
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• pp.28-35
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• 2002

The effect of physical parameters on water quality was analyzed using monitoring data of 193 agricultural reservoirs. The retention time of reservoirs ($t_d$) ranged between 10 and 140 days, and the ratio of drainage area (DA) to reservoir surface area (SA) was between 10 and 120. Both ratios of DA/SA and total area (TA)/ reservoir storage (ST) in Korean agricultural reservoirs were relatively greater than those in natural lakes in other countries. As retention time was plotted against DA/SA ratio, it was shorter in Korean reservoirs than natural lakes. The semi-logarithmic relationship between TA/SA and t>$t_d$ was $t_d\;=\;42.21(TA/ST)^{-1}$ (n = 50, $R^2\;=\;0.89$). While areal loading of total phosphorus (TP) was below $4\;gTP{\cdot}m^{-2}{\cdot}yr^{-1}$ in general, it exceeded $10\;gTP{\cdot}m^{-2}{\cdot}yr^{-1}$ in reservoirs where DA/SA ratio was greater than 100, which implies that areal loading of TP increases as DA/SA ratio increases. Chl-a concentration was positively related with the mean depth of reservoir, implying the higher Chl-a concentration with deeper the mean depth. Therefore, the deeper reservoir might be advantageous in water quality management perspective if other morphological conditions are similar. The empirical regression equation using physical parameters was also suggested in the estimation of TP concentration in the reservoirs. Combined information presented in this paper might be applicable to the water quality management in agricultural reservoirs.

• Pediatric Infection and Vaccine
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• v.20 no.1
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• pp.17-27
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• 2013

Purpose: Recently, two tests are commercially available for the identification of latent tuberculosis infection (LTBI): tuberculin skin test (TST) and interferon-${\gamma}$ release assay (IGRA). Due to its false positiveness, TST tends to be preferred by IGRA until now. In our study, we simultaneously performed both TST and QuantiFERON$^{(R)}$-TB Gold In-Tube (QFT-GIT) and compared their results. Methods: TST and QFT-GIT were done for the diagnosis of LTBI among children who visited pediatric out-patient clinic at St. Vincent's Hospital, The Catholic University of Korea from February of 2007 to May of 2008. The study group was stratified into two groups in terms of whether there was intrafamilial contact or not. Results: Out of total 35 children, 29 were tuberculosis (TB)-exposed cases and the remainders were diagnosed as clinical pulmonary TB. Among these 29 children, TST was positive 38.9% (7/18) for the intrafamilial and 45.5% (5/11) for the nonintrafamilial, and at the same time, the result for QFT-GIT was positive 5.6% (1/18) and 9.1% (1/11), respectively which implies that TST was more sensitive than QFT-GIT. Among 29 TB-exposed cases, 26 initially went through TST and QFTGIT together on their first visit to out-patient clinic, and 15 continued the follow-up tests. Out of total 41 cases collected, the agreement (known as kappa value) was 0.063 which was relatively low. Including 6 cases with pulmonary TB who were all positive for TST and only 5 being positive for QFT-GIT, the final kappa value was 0.334. Conclusion: In our study, the agreement for TST and QFT-GIT was low, and the majorities were almost the cases of positive TST. In current situation with lacking a gold standard test and limited data on children to adolescents, this result is quite alarming that the recent trend tends to replace TST by QFT-GIT when diagnosing LTBI.

• Tuberculosis and Respiratory Diseases
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• v.50 no.3
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• pp.310-319
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• 2001

Background : The peak flowmeter is very useful in monitoring of out-patients as well as those in emergency departments because of its convenience and simplicity with low cost. There have been many studies aimed at determining the accuracy and reproducibility of the peak flow meter in normal population. However, there is a paucity of reports regarding its accuracy in patients with chronic obstructive pulmonary disease(COPD) or asthma. The accuracy of the peak expiratory flow(PEF) measured with a mini-Wright peak flowmeter was assessed by a comparison with the results of a mass flow sensor. Methods : The PEF measurements were performed in 108 patients aged 19-82 years presenting with either a chronic obstructive lung disease or asthma before and after inhaling salbutamol. The PEF measurements from the mini-Wright flowmeter were compared with those obtained by the calibrated mass flow sensor. Results : The average of the readings taken by the mini-Wright meter were 37-39 l/min higher than those taken by the mass flow sensor. The average percentage error of the mini-Wright meter were higher, ranging less than 300 l/min. The mean of the differences between the values obtained using both instruments (the bias)$\pm$limits of agreement(${\pm}2$ SD) were $37.1{\pm}90\;l/min$ for the PEF(p<0.001). Conclusions : The mini-Wright peak flowmeter overestimated the flows in patients with COPD or asthma. It was also found that the accuracy of the mini-Wright peak flowmeter decreased in its mid to low range. The limits of agreement are wide and the difference between the two instruments is significant. Therefore, the measurements made between the two types of machines in patients with asthma or COPD cannot be used interchangeably.

• Archives of design research
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• v.19 no.4 s.66
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• pp.133-144
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• 2006

According to the latest report by the Customer Protection Board, those who moved into newly constructed buildings are complaining about unidentified pains, asking for more careful selection of constructive materials for prevention of such potential problems. It is internationally recognized today that ecological materials can serve a significant factor for users' health, environmental protection and better industrial competitiveness. This study examined eco-design aspects of each interior material through web site search, in order to help customers learn about and capitalize on eco materials in a proper manner. As a result, 1. It turned out that the domestic industry are giving an impetus to releasing new eco items focusing on lower VOCs emission or addition of functional components as part of the marketing strategy. However, it is recommended that company understand significance of life cycle, and produce eco-concept materials. 2. The reliable standard for choosing the domestic material is EL, HB, GR marks. It is desirable to enhance recycling technologies and expand the sustainable consumption. customer class, since many recycled items are not developed. 3. The sourcing is a vulnerable part in terms of the concept of being environment-friendly material. Therefore, many manufacturers should design the easy knock-down products and produce the good items using recycled materials instead of new raw materials. Also solutions for making the energy from burning material should be studied. 4. The guidebook or manual with correct information about eco-materials is required to promote production and consumption with sustainable concept. 5. Many manufacturers are emphasizing ecological materials for customers, but some of them intended to disrupt customers' proper selection by promoting even unverified items to be environment-friendly.

• Korean Journal of Remote Sensing
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• v.31 no.5
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• pp.449-459
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• 2015

The conventional National Forest Inventory(NFI)-based forest carbon stock estimation method is suitable for national-scale estimation, but is not for regional-scale estimation due to the lack of NFI plots. In this study, for the purpose of regional-scale carbon stock estimation, we created grid-based forest carbon stock maps using spatial ancillary data and two types of up-scaling methods. Chungnam province was chosen to represent the study area and for which the $5^{th}$ NFI (2006~2009) data was collected. The first method (method 1) selects forest type map as ancillary data and uses regression model for forest carbon stock estimation, whereas the second method (method 2) uses satellite imagery and k-Nearest Neighbor(k-NN) algorithm. Additionally, in order to consider uncertainty effects, the final AGB carbon stock maps were generated by performing 200 iterative processes with Monte Carlo simulation. As a result, compared to the NFI-based estimation(21,136,911 tonC), the total carbon stock was over-estimated by method 1(22,948,151 tonC), but was under-estimated by method 2(19,750,315 tonC). In the paired T-test with 186 independent data, the average carbon stock estimation by the NFI-based method was statistically different from method2(p<0.01), but was not different from method1(p>0.01). In particular, by means of Monte Carlo simulation, it was found that the smoothing effect of k-NN algorithm and mis-registration error between NFI plots and satellite image can lead to large uncertainty in carbon stock estimation. Although method 1 was found suitable for carbon stock estimation of forest stands that feature heterogeneous trees in Korea, satellite-based method is still in demand to provide periodic estimates of un-investigated, large forest area. In these respects, future work will focus on spatial and temporal extent of study area and robust carbon stock estimation with various satellite images and estimation methods.

• Economic and Environmental Geology
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• v.51 no.1
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• pp.67-76
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• 2018

This study reviews three eco-friendly energy towns with hybrid thermal energy supply systems and borehole thermal energy storage (BTES) in Canada and Denmark. The district heating and cooling systems were designed by using multi-source energy for the higher efficiency and reliability as well as environment. ADEU (Alexandra District Energy Utility) located at the developing area in the city of Richmond, Canada was designed to supply district energy with the installation of 726 borehole heat exchangers (BHEs) and a backup boiler using natural gas. DLSC (Drake Landing Solar Community) located in the town of Okotoks, Canada is a district system to store solar thermal energy underground during the summer season by seasonal BTES with 144 BHEs. Brædstrup Solpark district heating system located in Denmark has been conducted energy supply from multiple energy sources of solar thermal, heat pump, boiler plants and seasonal BTES with 48 BHEs. These systems are designed based on social and economic benefits as well as nature-friendly living space according to the city based energy perspective. Each system has the energy center which distribute the stored thermal energy to each house for heating during the winter season. The BHE depth and ground thermal storage volume are designed by the heating and cooling load as well as the condition of ground water flow and thermophysical properties of the ground. These systems have been proved the reliance and economic benefits by providing consistent energy supply with competitive energy price for many years. In addition, the several expansions of the service area in ADEU and Brædstrup Solpark have been processed based on energy supply master plan. In order to implement this kind of project in our country, the regulation and policy support of government or related federal organization are required. As well as the government have to make a energy management agency associated with long-term supply energy plan.

• Korean Journal of Environmental Agriculture
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• v.36 no.4
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• pp.279-287
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• 2017

BACKGROUND: Many farmers who cultivate the strawberries for export have used agricultural chemicals which MRL (Maximum Residue Limits) of main export target countries or simultaneous multi-residue analysis in Korea have not been established. Among them, the cyenopyrafen and cyflumetofen were selected and applied to this study to determine the PHI (pre-harvest interval) which is appropriate to the PLS (Positive List System) criterion (0.01 mg/kg) and to investigate the residual amounts in the samples. In addition, Fifty pesticides were monitored to check up whether it is suitable or not for main export target countries. METHODS AND RESULTS: Cyenopyrafen and cyflumetofen were spayed out to the strawberries. Samples for residual analyses were taken for maximum 60 days. After sampling, they were extracted by the QuEChERS method and analyzed using the LC-MS/MS. Cyenopyrafen and cyflumetofen were detected in a range of 0.0106~2.6517 mg/kg and of 0.0005~1.4480 mg/kg, respectively. From this results, they were found to be suitable for PLS concentration after 30 or 45 days after spray. In addition, they were detected in most samples that were selected at random. Their concentrations were higher than the PLS criterion in the maximum twenty samples. Twelve of pesticides unsuitable for main export target countries have been detected in the monitoring of simultaneous multi-residue analysis. The result indicates they are unsuitable for export since they excesses over PLS criterion. CONCLUSION: The monitoring result showed it is necessary to establish the pesticide standards of safe use suitable for the PLS criterion. In addition, it is considered continues management and inspection are needed to solve problems caused by unsuitable pesticides in export strawberries.

• Journal of Biomedical Engineering Research
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• v.25 no.5
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• pp.421-430
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• 2004

Clinically, it is almost impossible for a physician to distinguish subtle changes of frequency spectrum by using a stethoscope alone especially in the early stage of thrombus formation. Considering that reliability of mechanical valve is paramount because the failure might end up with patient death, early detection of valve thrombus using noninvasive technique is important. Thus the study was designed to provide a tool for early noninvasive detection of valve thrombus by observing shift of frequency spectrum of acoustic signals with computer aid diagnosis system. A thrombus model was constructed on commercialized mechanical valves using polyurethane or silicon. Polyurethane coating was made on the valve surface, and silicon coating on the sewing ring of the valve. To simulate pannus formation, which is fibrous tissue overgrowth obstructing the valve orifice, the degree of silicone coating on the sewing ring varied from 20％, 40％, 60％ of orifice obstruction. In experiment system, acoustic signals from the valve were measured using microphone and amplifier. The microphone was attached to a coupler to remove environmental noise. Acoustic signals were sampled by an AID converter, frequency spectrum was obtained by the algorithm of spectral analysis. To quantitatively distinguish the frequency peak of the normal valve from that of the thrombosed valves, analysis using a neural network was employed. A return map was applied to evaluate continuous monitoring of valve motion cycle. The in-vivo data also obtained from animals with mechanical valves in circulatory devices as well as patients with mechanical valve replacement for 1 year or longer before. Each spectrum wave showed a primary and secondary peak. The secondary peak showed changes according to the thrombus model. In the mock as well as the animal study, both spectral analysis and 3-layer neural network could differentiate the normal valves from thrombosed valves. In the human study, one of 10 patients showed shift of frequency spectrum, however the presence of valve thrombus was yet to be determined. Conclusively, acoustic signal measurement can be of suggestive as a noninvasive diagnostic tool in early detection of mechanical valve thrombosis.