• Journal of the Korea Organic Resources Recycling Association
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• v.2 no.2
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• pp.19-29
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• 1994

A large volume of paper mill sludge(PMS) is produced every day from paper industries after treatments of waste water and it costs too much to dispose of the sludge. Since PMS consists mostly of biodegradable organic matter, cellulose, it is desirable to recycle it by proper treatments such as composting. In this study, experiments were conducted using a small scale reactor(12l) to establish optimum conditions for efficient composting of PMS of which initial pH, C/N ratio, and moisture content were 7.1, 28~30, and 60~65%, respectively. No heavy metals such as mercury, cadmimum, and lead were not detected in the PMS. Various levels of forced aeration, 1 minute aeration per every 30, 60, 120, 240, and 480 minutes were applied and 1 minute aeration per 60 and 120 minutes found to be proper for composting of 8l PMS in this system. Relationship between $CO_2$ production and temperatures was positively correlated with r> 0.82 suggesting that the normal decomposition of PMS by microorganisms occurred. However, under the condition of aeration interval over than 240 minutes, a negative relationship between two parameters was found indicating the occurrence of abnormal(maybe anaerobic) degradation. The amount of added nitrogen also affected composting of PMS resulting in the increase of $CO_2$ production and temperature. Semi-field tests using 100kg PMS in a static pile sysem showed that PMS could be composted efficiently under optimal environmental conditions. The parameters determining efficiency of composting such as C/N ratio, aeration, moisture content, and pH need to be monitored.

• Radiation Oncology Journal
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• v.11 no.1
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• pp.51-58
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• 1993

We tried to establish the theoretical basis of clinical use of combined modality of hyperthermia and radiation therapy. For this purpose, we made an in vitro experiment in order to get the synergistic and/or additive effects on the cell killing of hyperthermia combined with radiation therapy by using the microwave-hyperthermia machine already installed at our department. In our experiment, we use two human cell lines: MKN-45 (adenocarcinoma of stomach) and K-562 (leukemia cell lines). In cases of combined treatments of hyperthermia and gamma-irradiation, the therapeutic effect was the highest in the simultaneous trial. Hyperthermia after gamma irradiation showed slightly higher therapeutic effect than that before irradiation without significant difference, but its effect was the same in the interval of 6 hours between hyperthermia and irradiation. The higher temperature and the longer treatment time were applied, the higher therapeutic effects were observed. We could observe the thermoresistance by time elapse at $43^{\circ}C$. When hyperthermia was done for 30 minutes at the same temperature, thermal enhancement ratio (TER) at DO. 01 (dose required surviving fraction of 0.01) were $2.5{\pm}0.08,\;3.75{\pm}0.18$, and $5.0{\pm}0.15\;at\;436{\circ}C,\;44^{\circ}C,\;and\;45^{\circ}C$ respectively in K-562 leukemia cell lines. Our experimental data showed that more cell killing effect can be obtained in the leukemia cell lines, although they usually are known to be radiosensitive, when treated with combined hyperthermia and radiation therapy. Furthermore, our data show that leukemia cell lines may have various intrinsic radiosensitivity, especially in vitro experiments. The magnitude of cell killing effect, however, will be less than that of MKN-45.

• Journal of Preventive Medicine and Public Health
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• v.30 no.4 s.59
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• pp.830-839
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• 1997

Painting is risky work to occupational skin disease. This research was carried out to investigate the prevalence of occupational skin diseases in painting department of a shipyard company in June 1996. Dermatological examination, self-administered questionnaire survey were conducted. Exposed group(n=379) was selected randomly in painting department and control of group(n=151) was selected in those who had not exposed to paints or solvents. The prevalence of contact dermatitis(11.9%) is significantly elevated compared with control of group(2.6%), and odds ratio(OR) is 4.95 (95% confidence interval[CI]: 1.75-14.02). The prevalence of Tinea pedis, the most common skin disease, in exposure group is 48.0%, and its odds ratio(OR) is significantly elevated compared with control group (OR:3.18, 95% CI: 2.06-4.90). Pompholyx is also significantly elevated in prevalence(11.9%) and OR(OR:6.64, 95% CI:2.03-21.69). There were no difference in the prevalence of contact dermatitis, Tinea pedis, and pompholyx by use of personal protective equipments(PPE), job categories, and duration of employment in painting department. In exposure group, 71.1% suffer from contact dermatitis improved in vacation or holiday and 68.9% of them had lesion on exposed area, it suggest that contact dermatitis in exposed group is related to their work. In conclusion, workers in painting department have high risks of contact dermatitis, Tinea pedis, and pompholyx. A health policy should be provided to prevent skin disease among painting department.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.7
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• pp.868-875
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• 2017

The aim of the present study was to investigate antioxidant nutrient intake and risk of metabolic syndrome based on stress level in rural Korean women. Subject were participants from the Multi-Rural Communities Cohort Study, which was a part of the Korean Genome and Epidemiology Study. According to scores of the Psychosocial Well-Being Index Short-Form, a total of 10,111 subjects were classified into 'low stress group (n=8,015)' from 0 to 26 points and 'high stress group (n=2,096)' above 27 points. Data were collected using self-administered questionnaires, anthropometric measurements, and blood chemical analysis. Dietary nutrient consumption was assessed by a semi-quantitative food frequency questionnaire. High stress group showed lower intake of antioxidant nutrients, such as vitamin A, vitamin C, vitamin E, folate, zinc, and carotene compared to the low stress group. Intake of fruits and vegetable was lower in the high stress group compared to the low stress group. Subjects with high stress showed higher risk of hypertension [odd ratio (OR), 95% confidence interval (CI)=1.226 (1.112~1.351)] and hypertriglyceridemia [OR, 95% CI=1.227 (1.110~1.356)] than subjects with low stress. High stress group had a significantly greater odds ratio for metabolic syndrome compared with the low stress group [OR, 95% CI=1.216 (1.101~1.342]). Thus, the present study suggests that high stress might be associated with low intake of antioxidant nutrients and high risk of metabolic syndrome in rural Korean women.

• Tuberculosis and Respiratory Diseases
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• v.46 no.6
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• pp.767-774
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• 1999

Background : Tuberculous mediastinal lymphadenitis (TML) is a relatively commonly encountered in Korea. However, there were no datas available on TML without other combined tuberculous infections in Korea. We retrospectively analyzed clinical manifestations, radiologic findings, Chest CT scan findings, the duration of treatment, and follow up Chest CT scan findings of 23 cases who had only TML. Method : 23 cases from 1991 to 1997 with TML confirmed by biopsy and had no other combined tuberculous infections were studied retrospectively. Results : Of the 23 cases, 7 cases were male and 16 female. The male to female ratio was 1 : 2.4. Mean age was 31 years and the most prevalent age group was the 3rd decade(43%). The most common presenting symptoms were fever(39%) followed by no symptom, cough, swallowing difficulty, and chest discomfort. On simple chest X-ray, mediastinal enlargement were noted in 20 cases(90%). The most frequently involved site was the paratracheal node in 11 cases with the right to left side involvement ratio being 4.6 : 1. On chest CT scan, the most commonly enlarged node was the paratracheal node(33%) followed by the subcarinal(20%), hilar(13%), tracheobronchial (8%), subaortic(8%), supraclavicular(8%) and anterior. mediastinal nodes. 6 cases were dropt out due to incomplete follow up. Thirteen cases were treated with HERZ regimen and the mean duration of treatment was 14 months. Three cases were treated with second line drug regimens(Tarivid, Pyrazinamide, Streptomycin plus Ethambutol or Para-aminosalicylic acid) for 18 months. In HERZ groups, one case was recurred after 10 months later and retreatment was done by same HERZ regimen during 12 months. Follow up chest CT scan after completion of treatment were done in 13 cases and that revealed more than a 50% decrease in size in 77% of the cases and no interval change in 23% of the cases. Conclusion : In cases of TML without other combined tuberculous infection, the minimal duration of treatment was required 12 months by HERZ regimen and 18 months by a 2nd line regimen or more. Further studies will be needed to confirm the treatment duration for TML without other combined tuberculous infections.

• Journal of agricultural medicine and community health
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• v.23 no.2
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• pp.229-242
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• 1998

Face-to-face interviews were carried out to investigate the relationship between social networks and hypertension in 958 rural residents(males=440, females=518) aged 60-64 of a community-dwelling sample of Dalsung County from April to September in 1996. Eight elements of social network were measured : marital status, regular religious attendance, membership in groups, number of friends, relatives, siblings, children, grandchildren. Hypertensives were defined as meeting at least one of following criteria : hypertension history, systolic blood pressure more than 160 mmHg, diastolic blood pressure more than 95 mmHg. In univariate logistic regression for males, having 1-4 friends vs. none showed odds ratio 0.43 (95% Confidence interval CI 0.19-0.96) and having 2-3, 4 and more than 5 children had reduced prevalence of hypertension with odds ratios 0.21 (95% CI 0.06-0.72), 0.14 (95% CI 0.04-0.49), 0.24 (95% CI 0.07-0.82), respectively when compared with persons without children. In females, there was no elements of social network statistically significant. Having 5-9 grandchildren vs. none showed a marginally significant odds ratio 0.42. In multivariate logistic regression models for males with adjustment for age, education, body mass index, smoking and drinking, number of friends and children showed increased odds ratios and number of close relatives gained a statistically significant odds ratios (0.44-0.50). In females, the adjustment yielded little changes of odds ratios except number of grandchildren which gained a statistically significance. These results suggest that only a certain elements of social network may be associated with reduced risk of hypertension and they may be different between genders in rural resident aged 60-64.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.4
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• pp.445-456
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• 2009

Statement of problem: Many studies have been conducted to improve the primary stability of implants by providing bioactive surfaces via surface treatments. Increase of surface roughness may increase osteoblast activity and promote stronger bonding between bone and implant surface and it has been reported that bioactive surface or titanium can be obtained through alkali and heat treatment. Purpose: The purpose of this study was to evaluate the stability of alkali and heat treated implants via histomorphometric analysis. Material and methods: Specimens were divided into three groups; group 1 was the control group with machined surface, the other groups were treated for 24 hours in 5 M NaOH solution and heat treated for 1 hour at $600^{\circ}C$ in the atmosphere (group 2) and vacuum (group 3) conditions respectively. Surface characteristics were analyzed and fixtures were implanted into rabbits. The specimens were histologically and histomorphometrically compared according to healing periods and change in bone composition were analyzed with EPMA (Electron Probe Micro Analyzer). Results: 1. Groups treated with alkali and heat showed increase of oxidization layer and Na ions. Groups 2 which was heat treated in atmosphere showed significant increase of surface roughness (P<.05). 2. Histomorphometric analysis showed significant increase in BIC (bone to implant contact) according to increase in healing period and there was significant increases in groups 2 and 3 (P<.05). 3. BA(bone area) ratio showed similar results as contact ratio, but according to statistical analysis there was significant increase according to increase in healing period in group 2 only (P<.05). 4. EPMA analysis revealed no difference in gradation of bone composition of K, P, Ca, Ti in surrounding bone of implants according to healing periods but groups 2 and 3 showed increase of Ca and P in the initial stages. Conclusion: From the results above, it can be considered that alkali and heat treated implants in the atmosphere have advantages in osseointegration in early stages and may decrease the time interval between implantation and functional adaptation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.5
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• pp.375-395
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• 2006

Purpose: Lingual nerve (LN) damage may be caused by either tumor resection or injury such as wisdom tooth extraction, Although autologous nerve graft is sometimes used to repair the damaged nerve, it has the disadvantage of necessity of another operation for nerve harvesting. Moreover, the results of nerve grafting is not satisfactory. The nerve growth factor (NGF) is well-known to play a critical role in peripheral nerve regeneration and its local delivery to the injured nerve has been continuously tried to enhance nerve regeneration. However, its application has limitations like repeated administration due to short half life of 30 minutes and an in vivo delivery model must allow for direct and local delivery. The aim of this study was to construct a well-functioning $rhNGF-{\beta}$ adenovirus for the ultimate development of improved method to promote peripheral nerve regeneration with enhanced and extended secretion of hNGF from the injured nerve by injecting $rhNGF-{\beta}$ gene directly into crush-injured LN in rat model. Materials and Methods: $hNGF-{\beta}$ gene was prepared from fetal brain cDNA library and cloned into E1/E3 deleted adenoviral vector which contains green fluorescence protein (GFP) gene as a reporter. After large scale production and purification of $rhNGF-{\beta}$ adenovirus, transfection efficiency and its expression at various cells (primary cultured Schwann cells, HEK293 cells, Schwann cell lines, NIH3T3 and CRH cells) were evaluated by fluorescent microscopy, RT-PCR, ELISA, immunocytochemistry. Furthermore, the function of rhNGF-beta, which was secreted from various cells infected with $rhNGF-{\beta}$ adenovirus, was evaluated using neuritogenesis of PC-12 cells. For in vivo evaluation of efficacy of $rhNGF-{\beta}$ adenovirus, the LNs of 8-week old rats were exposed and crush-injured with a small hemostat for 10 seconds. After the injury, $rhNGF-{\beta}$ adenovirus($2{\mu}l,\;1.5{\times}10^{11}pfu$) or saline was administered into the crushed site in the experimental (n=24) and the control group (n=24), respectively. Sham operation of another group of rats (n=9) was performed without administration of either saline or adenovirus. The taste recovery and the change of fungiform papilla were studied at 1, 2, 3 and 4 weeks. Each of the 6 animals was tested with different solutions (0.1M NaCl, 0.1M sucrose, 0.01M QHCl, or 0.01M HCl) by two-bottle test paradigm and the number of papilla was counted using SEM picture of tongue dorsum. LN was explored at the same interval as taste study and evaluated electro-physiologically (peak voltage and nerve conduction velocity) and histomorphometrically (axon count, myelin thickness). Results: The recombinant adenovirus vector carrying $rhNGF-{\beta}$ was constructed and confirmed by restriction endonuclease analysis and DNA sequence analysis. GFP expression was observed in 90% of $rhNGF-{\beta}$ adenovirus infected cells compared with uninfected cells. Total mRNA isolated from $rhNGF-{\beta}$ adenovirus infected cells showed strong RT-PCR band, however uninfected or LacZ recombinant adenovirus infected cells did not. NGF quantification by ELISA showed a maximal release of $18865.4{\pm}310.9pg/ml$ NGF at the 4th day and stably continued till 14 days by $rhNGF-{\beta}$ adenovirus infected Schwann cells. PC-12 cells exposed to media with $rhNGF-{\beta}$ adenovirus infected Schwann cell revealed at the same level of neurite-extension as the commercial NGF did. $rhNGF-{\beta}$ adenovirus injected experimental groups in comparison to the control group exhibited different taste preference ratio. Salty, sweet and sour taste preference ratio were significantly different after 2 weeks from the beginning of the experiment, which were similar to the sham group, but not to the control group.

• Journal of Preventive Medicine and Public Health
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• v.35 no.2
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• pp.153-159
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• 2002

Objectives : To evaluate the accuracy of the registered cause of death in a county and its related factors. Methods : The data used in this study was based on 504 cases, in a county of Chonnam province, registered between January and December 1998. Study subjects consisted of 388 of the 504 cases, and their causes of death were established by an interview survey of the next of kin or neighbor and medical record surveys. We compared the registered cause of death with the confirmed cause of death, determined by surveys and medical records, and evaluated the factors associated with the accuracy of the registered cause of death. Results : 62.6% of the deaths were concordant with 19 Chapters classification of cause of death. external causes of mortality, endocrine, nutritional and metabolic diseases, neoplasms and diseases of the circulatory system showed the good agreement between the registered cause of death and the confirmed cause of death. The factors relating to the accuracy of the registered cause of death were the doctors' diagnosis for the cause of death (adjusted Odds Ratio: 2.67, 95% Confidence Interval: 1.21-5.89) and the grade of the public officials in charge of the death registry (adjusted Odds Ratio: 0.30, 95% CI=0.12-0.78). Conclusions : The accuracy of the registered cause of death was not high. It could be improved by using the doctors' diagnosis for death and improving the job specification for public officials who deal with death registration.

• Korean Journal of Remote Sensing
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• v.39 no.6_3
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• pp.1779-1790
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• 2023

Satellite-based fog detection algorithms are being developed to detect fog in real-time over a wide area, with a focus on the Korean Peninsula (KorPen). The GEO-KOMPSAT-2A/Advanced Meteorological Imager (GK2A/AMI, GK2A) satellite offers an excellent temporal resolution (10 min) and a spatial resolution (500 m), while GEO-KOMPSAT-2B/Geostationary Ocean Color Imager-II (GK2B/GOCI-II, GK2B) provides an excellent spatial resolution (250 m) but poor temporal resolution (1 h) with only visible channels. To enhance the fog detection level (10 min, 250 m), we developed a fused GK2AB fog detection algorithm (FDA) of GK2A and GK2B. The GK2AB FDA comprises three main steps. First, the Korea Meteorological Satellite Center's GK2A daytime fog detection algorithm is utilized to detect fog, considering various optical and physical characteristics. In the second step, GK2B data is extrapolated to 10-min intervals by matching GK2A pixels based on the closest time and location when GK2B observes the KorPen. For reflectance, GK2B normalized visible (NVIS) is corrected using GK2A NVIS of the same time, considering the difference in wavelength range and observation geometry. GK2B NVIS is extrapolated at 10-min intervals using the 10-min changes in GK2A NVIS. In the final step, the extrapolated GK2B NVIS, solar zenith angle, and outputs of GK2A FDA are utilized as input data for machine learning (decision tree) to develop the GK2AB FDA, which detects fog at a resolution of 250 m and a 10-min interval based on geographical locations. Six and four cases were used for the training and validation of GK2AB FDA, respectively. Quantitative verification of GK2AB FDA utilized ground observation data on visibility, wind speed, and relative humidity. Compared to GK2A FDA, GK2AB FDA exhibited a fourfold increase in spatial resolution, resulting in more detailed discrimination between fog and non-fog pixels. In general, irrespective of the validation method, the probability of detection (POD) and the Hanssen-Kuiper Skill score (KSS) are high or similar, indicating that it better detects previously undetected fog pixels. However, GK2AB FDA, compared to GK2A FDA, tends to over-detect fog with a higher false alarm ratio and bias.