• Korean Journal of Ecology and Environment
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• v.50 no.2
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• pp.238-253
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• 2017

The sewage and wastewater (SAW) are a well-known major source of eutrophication and greentide in freshwaters and also a potential source of thermal pollution; however, there were few approaches to thermal effluent of SAW in Korea. This study was performed to understand the behavioral dynamics of the thermal effluents and their effects on the water quality of the connected streams during winter season, considering domestic sewage, industrial wastewater and hot spring wastewater from December 2015 to February 2016. Sampling stations were selected the upstream, the outlet of SAW, and the downstream in each connected stream, and the water temperature change was monitored toward the downstream from the discharging point of SAW. The temperature effect and its range of SAW on the stream were dependent not only on the effluent temperature and quantity but also on the local air temperature, water temperature and stream discharge. The SAW effects on the stream water temperature were observed with temperature increase by $2.1{\sim}5.8^{\circ}C$ in the range of 1.0 to 5.5 km downstream. Temperature effect was the greatest in the hot spring wastewater despite of small amount of effluent. The SAW was not only related to temperature but also to the increase of organic matter and nutrients in the connected stream. The industrial wastewater effluent was discharged with high concentration of nitrogen, while the hot spring wastewater was high in both phosphorus and nitrogen. The difference between these cases was due to with and without chemical T-P treatment in the industrial and the hot spring wastewater, respectively. The chlorophyll-a content of the attached algae was high at the outlet of SAW and the downstream reach, mostly in eutrophic level. These ecological results were presumably due to the high water temperature and phosphorus concentration in the stream brought by the thermal effluents of SAW. These results suggest that high temperature of the SAW needs to be emphasized when evaluating its effects on the stream water quality (water temperature, fertility) through a systematized spatial and temporal investigation.

• The korean journal of orthodontics
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• v.29 no.6 s.77
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• pp.689-698
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• 1999

Although the purpose of orthodontic treatment is to increase the function and aesthetics of the jaws as well as to increase stability, there are side effects from the treatment itself such as root resorption and alveolar bone resorption. Such resoiption of the apical root is unpredictable and may even proceed into the dentin layer. Once the process has begun, it is irreversible. By evaluating the effects of different oral habits, especially that ef nail biting, and their correlation with the root and the periodontal tissues, the appropriate biomechanics for orthodontic treatment can be taken into consideration. The possibility of root resorption and alveolar bone loss during orthodontic treatment can also be considered. Also, any legal problems that might occur may be pondered as well. Among the male md female patients of the ages 10~15, 63 were chosen as the test group with known nail biting habits at time of examination and within the same age range those without nail biting habits as the control group. The test group was composed of 30 males and 33 females. The control group had 31 males and 32 females. The result from this study were as follows : 1. Of the 63 patients of both the test and control groups, the male-to-female-ratio was 1:1, and had no statistically significant difference in male and female root resorption. 2. In comparing crown length of the test and control groups, no significant difference existed, but in root length, maxillary and mandibular right and left central incisors and mandibular right lateral incisors had a smaller value. (p<0.001) 3. Average crown-to-root ratio of the test group on the periapical view show a noticeably high value for the maxillary and mandibular right and left central incisors and mandibular right and left lateral incisors. (p<0.01) 4. In comparing and evaluating the alveolar bone loss measured from the cemento-enamel junction to the alveolar bone crest, mesial surfaces of the maxillary and mandibular right and left central incisors and distal surface of maxillary right central incisor of the test group showed greater loss of crestal bone than the control. (p<0.05)

• Neonatal Medicine
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• v.18 no.2
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• pp.320-327
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• 2011

Purpose: To determine the effect of changing practice guidelines designed to avoid hyperoxia or hypoxia in very low birth weight or very preterm infants. Methods: We analyzed a database of <1,500 g birth weight or <32 weeks of gestation infants who were born and admitted to the neonatal intensive care unit of Chungnam National University Hospital from January 2007 to July 2010. First, we defined the relationship between arterial partial pressure of oxygen ($PaO_2$) and pulse oxygen saturation ($SpO_2$). When we evaluated 96 pairs of $PaO_2$ and $SpO_2$ measurements, oxygen saturation was 90-94% at a $PaO_2$ of 43-79 mmHg on the oxyhemoglobin dissociation curve, according to pulse oximetry. Based on this observation, a change in practice was instituted in August 2008 with the objective of avoiding hypoxia and hyperoxia in preterm infants with targeting a $SpO_2$ 90-94% (period II). Before the change in practice, high alarms for $SpO_2$ were set at 100% and low alarms at 95% (period I). Results: Sixty-eight infants the met enrollment criteria and 38 (56%) were born during period II, after the change in $SpO_2$ targets. Demographic characteristics, except gender, were similar between the infants born in both periods. After correcting for the effect of confounding factors, the rates for mortality, severe retinopathy of prematurity, and IVH attended to be lower than those for infants in period II. No difference in the rate of patent ductus arteriosus needed to treat was observed. Conclusion: A change in the practice guidelines aimed at avoiding low oxygen saturation and hyperoxia did not increase neonatal complication rates and showed promising results, suggesting decreased mortality and improvements in short term morbidity. It is still unclear what range of oxygen saturation is appropriate for very preterm infants but the more careful saturation targeting guideline should be considered to prevent hypoxemic events and hyperoxia.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.3
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• pp.182-191
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• 2020

A field test and a phytotron study were performed over two years to examine whether rice varieties originated from higher altitude areas have lower optimum grain filling temperatures for yield improvement than the varieties from South Korea. Three varieties originated from North Korea and three varieties from northern China were compared to the same number of varieties from South Korea. In a field study, the optimum grain filling temperatures over 40 days after heading were 22.6 - 23.0℃, 21.5 - 22.3℃, and 21.5 - 23.6℃ for the varieties from North Korea, northern China, and South Korea, respectively, resulting in no significant difference among varietal groups. Meanwhile, the heading dates of the early maturing varieties from North Korea and China were 7 - 12 days earlier than that of the early maturing Odae variety from South Korea during the first transplant of 2017. The phytotron study, in which different temperature regimes were imposed from flowering/fertilization to harvest with constant daily mean temperatures, revealed that milled rice weight did not decrease under low temperatures, even at 16℃, compared to that at 22℃. At the fourth transplant in the field study, mean temperature lower than 10℃ appeared before rice grains were fully developed, resulting in yield reductions. It was concluded that rice varieties adaptable to high-altitude areas do not have lower optimum grain filling temperatures but, instead, possess shorter growth durations. It was further suggested that the optimum grain filling temperature of rice observed under natural conditions could be attributed to the lowering temperature at the late filling stage under temperate climatic conditions.

• Journal of Nutrition and Health
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• v.53 no.2
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• pp.190-202
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• 2020

Purpose: This study aims to evaluate the recognition, purchase, and intake status of edible insects in adults, who are the main consumers of edible insects, and to provide the information necessary to expand the production and consumption of edible insects and related products in the future. Methods: A total of 453 adults (172 males and 281 females) aged 19 years and older were surveyed regarding their awareness of edible insects, purchase and consumption experience, and intention to purchase and consume, and the differences between them were analyzed according to gender and age groups. Data collection took place from December 2018 to January 2019. Results: Those who had knowledge of edible insects accounted for 87.0%, whereas those who had more than average knowledge were 75.9%, suggesting recognition was relatively high. Men had more experience than women in purchasing or consuming edible insects and related products (45.9% vs. 31.0%, p < 0.01). In terms of age, experience was 22.5% in 20-30s, 44.6% in 40-50s, and 63.1% in 60s and older, showing significant growth as age increased (p < 0.001). The satisfaction level of edible insects was highest in taste (3.4 points), and especially for shape and appearance, it decreased as age reduced (p < 0.001). The most common reason for not being willing to use edible insects was feeling repulsive (4.1 points), which was significantly more common in women than in men (4.3 vs. 3.9, p < 0.001), and lower with age (p < 0.001). The most needed information display for using edible insects was country of origin (63.8%), the main nutrient in edible insects was protein (93.6%), and the most preferred form of products was powder (39.5%). Conclusion: According to the above results, the recognition of edible insects was high, whereas experience of using edible insects and intention to use edible insects were low especially in women and younger groups. The reason for this is that consumers are dissatisfied with edible insects due to their appearance. This study is expected to be used as basic data for expanding the production and consumption of edible insects and related products in the future.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.4
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• pp.257-266
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• 2008

PAHs are of mainly anthropogenic origin from urban runoff, oil spill and combustion of fossil fuels. Some PAHs are potentially carcinogenic and mutagenic to aquatic organisms. This study was carried out to survey the contamination of PAHs in the column sediments around Gwangyang bay. Yeosu petrochemical industrial complex, POSCO(Pohang steel compony) and Gwangyang container harbor are located near the bay. The column sediments were collected at 4 stations(A, B, C and D) and fractionated at intervals of two-centimeter depth on July 29, 1999. PAHs in colmn sediment samples were extracted in soxhlet extractor and were identified and quantified by GC-MS. PAHs compounds were analyzed and found to be 13 species. Total PAHs concentrations in the column sediments ranged from 275.04 to 2,838.64${\mu}g/kg$ dry wt. Naphthalene had the highest concentration in the range of 40.60 to 2,294.06${\mu}g/kg$ dry wt. and Anthracene had the lowest concentration in the range of 2.63 to 11.30${\mu}g/kg$ dry wt. The correlation coefficients between individual PAHs and total PAHs in the column sediments were relatively higher in the low molecular compounds such as Naphthalene, Acenaphthylene and Phenanthrene. The relationship between the P/A(Phenanthrene/Anthracene)ratio and F/P(Fluoranthene/Pyrene)ratio showed that P/A ratio was generally above 10 and F/P ratio was above 1 in all sediment samples. These data indicate that PAHs in the column sediments around Gwangyang bay seem to be of both pyrolytic and petrogenic origin The values of PAHs in the column sediments were lower than the biological effect guidelines.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.4
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• pp.340-347
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• 2001

Seasonal variation of the elemental and biochemical composition of the suspended particulate matter (SPM) was investigated in terms of quantity and quality of diets for suspension feeders from July 1999 to August 2000 in two coastal bay systems of Gosung and Kangjin Bays in Korea. No clear patterns in the seasonal variations of SPM concentration were found in these two bay systems. The results indicated that the seasonal variation of SPM could not be considered the variation of food available to suspension-feeders. The simultaneous peaks in chlorophyll a and biochemical components in summer indicated that the quantity of the particulate organic matter primarily depended on phytoplankton productivity. However, no correlation between chlorophyll a and biochemical components [particulate protein (PPr), carbohydrate (PCHO) and lipid] were found, indicating that other processes might also contribute to the particulate organic matter in the period when the phytoplankton biomass was low. High C: Chl a and C:N, and carbohydrate peaks during the autumn to spring period suggested that resuspension of surface sediments was a probable process to supply the particulate organic matter. The food material, represented by summing up the total quantity of three biochemical components, was highest in spring with minor peaks during the period from autumn to the next spring, The food index, calculated as the ratio of food material to total SPM, did not generally exceed $6\%$ with short peaks during the year. Therefore, nutritional quality of SPM in the bays are relatively poor than in other more productive coastal waters in the world. Our results confirm that the measurement of a single chemical variable cannot describe fully the nutritive value of the seston available to suspension-feeders as previously proposed, and the biochemical composition of SPM can provide effective information on its origin and nutritive Quality.

• Korean Journal of Medicinal Crop Science
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• v.16 no.5
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• pp.356-370
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• 2008

This study was conducted for screening on antioxidant activity of 429 plants and selecting new potential antioxidant candidates. In vitro test models such as scavenging activity on DPPH radical and inhibitory activity on linoleic acid oxidation were used in the preliminary study. Flower of Sanguisorba officinalis, flower of Sedum kamtschaticum, flower of Rumex obtusifolius, and root of Sedum kamtschaticum showed very effective antioxidant activity on DPPH radical and linoleic acid oxidation. Those plants showed 8.1, 9.4, 9.9, $11{\mu}g/ml$ in DPPH radical scavenging activity as $SC_{50}$ and did 80.4, 80.1, 84.5, 88.0% in inhibition activity on linoleic acid oxidation, respectively. Root of Sedum middendorfianum M. showed positive effects in superoxide radical scavenging activity ($38.4{\mu}g/ml$) and inhibitory effect on $CuSO_4$-induced LDL oxidation (53.8% at final concentration of $1{\mu}g/ml$). Gleditsia japonica Mig. showed high antioxidant activity on LDL oxidation as 71.6% at final concentration of $1{\mu}g/ml$ and total phenol content of 958.5 mg% as tannic acid equivalent. In conclusion, we think that these plants having potent antioxidant activity might be studied further and could be used as new resources for many purposes including healthy food, functional cosmetics and drug development etc.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.12 no.1
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• pp.138-148
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• 2001

The focus of the research was on identifying the risk factors that may result in unprepared intercourse among the adolescent from an ecological systems prospective. A survey questionnaire was conducted from September through December 1999 to 2326 youths, ages from 13-18 years old. After eliminating thirty respondents from Unwed Mother's Home we found that 8.8% of the remaining respondents had experienced sexual intercourse. Of those, 5% of the female and 13.4% of male adolescents has had sexual intercourse, showing 2.7 times more for the male sample population. Broken down to age groups, 3.2% of the thirteen years old group and 19.2% of the eighteen years old group had experienced intercourse, an almost six fold increase in the older age group. To find out the differences between those who had and not had experienced intercourse the group was then divided into two comparative groups by same sex and age variables. Findings from comparative analysis identified five ecological system risk factors among the youth sample that had intercourse；First, individual factor：adolescents who thought less of themselves or didn't consider their potentials, those more exposed other risk behaviors such as drinking, smoking, drugs, runaway and come in contact with pornography, those who thought they knew more about sex and etc. Second, family factor：those who thought family was less important, had less supportive family, higher or lower income family and etc. Third, peer factor：Both groups thought friends were important and had their support. The group with intercourse experience seems to be think that more peers are experiencing other risk behavior. Fourth, school factor：Those in the group who had experienced intercourse seems to think school is less important and with lower academic achievements. Fifth, community factor：There were no statistical significant differences found between the two groups. The overall results from this study implies that if we want to prevent our youths from having unprepared intercourse during adolescence the significance of having meaningful emerging self, family relationship and school experience is important. This study identified the risk factors leading to adolescent sexual intercourse but further research is necessary in finding out about their predictability.

• Tuberculosis and Respiratory Diseases
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• v.51 no.2
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• pp.147-154
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• 2001

Background : Bronchoscopy has been widely used for a histologic diagnosis through a transbronchial lung biopsy or for staging of patients with peripheral lung cancer. However a transthoracic needle aspiration (TTNA) has been used more widely for a histologic diagnosis in patient with a small size nodule or a nodule located in the outer portion of the lung because of the low diagnostic yield of bronchoscopy in these cases. The role of bronchoscopy for staging is not well established in patients with peripheral lung cancer diagnosed by a TTNA or patients who are undergoing surgery without a histologic diagnosis. Method: To evaluate the role of bronchoscopy for the staging in patients with peripheral lung cancer, who were diagnosed by TTNA, the medical records of 86 patients with peripheral lung cancer who underwent bronchoscopyat Kyungpook National University Hospital between January 1995 and May 1997 were reviewed. Results : While 53 cases had normal bronchoscopic findings, 33 cases had abnormal bronchoscopic findings comprising 9 cases of tumor, 10 cases of infiltration and 14 cases of compression of which there were 25 cases of T1 and 8 T2 endoscopically. The bronchoscopic staging did not influence the changes of the clinical stage of lung cancer. The frequencies of bronchial involvement tended to increase as the sizes of the nodule increased. Among the 42 patients who underwent surgery, 9 patients staged higher after operation because of lymph node involvement in 8 patients and the involvement of the pulmonary artery in 1 patient. No case staged above after operation due to a bronchial invasion. Conclusion : These findings suggests that bronchoscopy is not useful for staging in patients with peripheral lung cancer diagnosed by a TTNA.