• Korean Journal of Soil Science and Fertilizer
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• v.31 no.3
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• pp.285-290
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• 1998

Thermophilic Bacillus species was studied as a microbial indicator to pursue the compost a application history. Thermophilic Bacillus species could be easily determined by the plate culture method within 12 hours in $65^{\circ}C$ incubator. The density of thermophilic Bacillus species in soils was gradually increased with the application rate of rice straw compost, and correlated to the soil organic matter content in $R^2=0.835^{**}$(n=32) coefficient on the 43-year-long term rice paddy fields.

• Biomedical Science Letters
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• v.24 no.3
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• pp.245-252
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• 2018

Heart rate recovery (HRR) is simply an indicator of autonomic balance and is a useful physiological indicator to predict cardiovascular morbidity and mortality. The purpose of this study was to compare the differences in HRR between metabolically healthy obesity group and metabolically unhealthy obesity and to ascertain whether heart rate recovery is a predictor of metabolic syndrome. Metabolic syndrome was defined according to the standards of the National Cholesterol Education Program Adult Care Panel III. Obesity was assessed according to WHO Asian criteria. It was classified into three groups of metabolically healthy non-obesity group (MHNO, n=113), metabolically healthy obesity group (MHO, n=66), metabolically unhealthy obesity (MUO, n=18). Exercise test was performed with Bruce protocol using a treadmill instrument. There was no difference in HRR between MHO and MUO ($32.71{\pm}12.25$ vs $25.53{\pm}8.13$), but there was late HRR in MUO than MHNO ($25.53{\pm}8.13$ vs $34.51{\pm}11.80$). HRR in obese was significantly correlated with BMI (r=-0.342, P=0.004), waist circumference (r=-0.246, P=0.043), triglyceride (r=-0.350, P=0.003), HbA1c (r=-0.315, P=0.009), insulin (r=-0.290, P=0.017) and uric acid (r=-0.303, P=0.012). HRR showed a lower prevalence of abdominal obesity, hypertriglyceridemia, and low HDL-cholesterol in the third tertile than in the first tertile. In conclusion, MHO had no difference in vagal activity compared with MHNO, but MUO had low vagal activity. HRR is associated with metabolic parameters and is a useful predictor of abdominal obesity, hypertriglyceridemia, and low HDL-cholesterolemia.

• Sleep Medicine and Psychophysiology
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• v.20 no.1
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• pp.22-30
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• 2013

Objectives: Sleep problems has been consistently reported as a suicidal risk factor in adults and, recently, also in adolescents. In this study, dividing study subjects by the previous suicidal behaviors (suicidal vs non-suicidal), we compared the group differences of suicidal risk factors, and examined the possibility of sleep as a suicidal risk factor. Methods: Study subjects were 561 (271 boys and 290 girls) from a community sample of high school students. Suicidal Risk Behavior Checklist, Center for Epidemiological Study-Depression (CES-D), Symptom Checklist-90-Revision (SCL-90-R) Anxiety and Aggression subscale, Pittsburg Sleep Quality Index (PSQI) were done. Results: Forty six students (8.1%) reported previous actual self-harm behavior as a suicidal attempt, 181 students (32.4%) reported having suicidal thought only. Three hundred thirty four students (59.5%) reported no previous suicidal behavior (thought and attempt, both). Suicidal behavior group showed higher score on risk behaviors such as school violence, substance use and internet addiction. CES-D, SCL-90-R, PSQI showed significant group difference. Logistic regression analysis showed suicidal risk were significantly associated with depression, stress in suicidal risk factors and sleep latency, daytime dysfunction in PSQI. Analysis of variance (ANOVA) shows the most prolonged sleep latency and increased index of all PSQI components except sleep efficiency in suicidal attempt group. Conclusions: Sleep Problems had a strong association with the suicidal risk behavior in adolescents. Sleep problems, especially, prolonged sleep latency, daytime dysfunction might be important markers for suicidal behavior. Screening for sleep problems in adolescents are encouraged for the parents, school teachers, and related medical physicians.

• Nutrition Research and Practice
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• v.14 no.1
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• pp.25-31
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• 2020

BACKGROUND/OBJECTIVES: To date, sodium intake has been evaluated based on spot urine instead of 24-hour (hr) urine collection. Nevertheless, the optimal method for assessing daily sodium intake remains unclear. SUBJECTS/METHODS: Fifteen male (age 32.7 ± 6.5 years) participants were offered 3 meals with a total of 9-10 g salt over 24 hours, and 24-hr urine was collected from the second-void urine of the first day to the first-void urine of the second day. Twenty-four-hr urinary sodium (24UNa) was estimated using Tanaka's equation and the Korean formula, and spot urine Na, potassium (K), chloride (Cl), urea nitrogen (UN), creatinine (Cr), specific gravity (SG) and osmolality (Osm) were measured. The ratios of urinary Na to other parameters were calculated, and correlations with total measured 24UNa were identified. RESULTS: Average 24-hr urine volume was 1,403 ± 475 mL, and measured 24UNa was 143.9 ± 42.1 mEq (range, 87.1-239.4 mEq). Measured 24UNa was significantly correlated with urinary Na/UN (r = 0.560, P < 0.01), urinary Na/Osm (r = 0.510, P < 0.01), urinary Na/Cr (r = 0.392, P < 0.01), urinary Na/K (r = 0.290, P < 0.01), 24UNa estimated using Tanaka's equation (r = 0.452, P < 0.01) and the Korean formula (r = 0.414, P < 0.01), age (r = 0.548, P < 0.01), weight (r = 0.497, P < 0.01), and height (r = 0.393, P < 0.01) in all spot urine samples. Estimated 24UNa based on the second-void spot urine of the first day tended to be more closely correlated with measured 24UNa than were estimates from the other spot urine samples. The significant parameters correlated with the second-void urine of the first day were urinary Na/K (r = 0.647, P < 0.01), urinary Na/Cr (r = 0.558, P < 0.05), and estimated 24UNa using Tanaka's equation (r = 0.616, P < 0.05) and the Korean formula (r = 0.588, P < 0.05). CONCLUSIONS: Second-void urine is more reliable than first-void urine for estimating 24UNa. Urinary Na/K in the second-void urine on the first day is significantly correlated with 24UNa. Further studies are needed to establish the most reliable index and the optimal time of urine sampling for predicting 24UNa.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.428-440
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• 2016

The purpose of this study was to identify the extent of and relationships among emotional labor, job stress, burnout and turnover intention and the factors influencing the turnover intention of care workers at long-term care hospitals. The study was approved by KUIRS, and the data were collected from August 12 to September 30, 2015, and analyzed using the SPSS WIN 18.0 program. The participants of this study were 200 care workers at ten different long-term care hospitals in B city and G province. Data were collected through self-reported questionnaires and analyzed by descriptive statistics, the t-test, ANOVA, Pearson's correlation coefficients, and Stepwise multiple regression. The turnover intention was significantly correlated with emotional labor (r=.372, p<.001), job stress (r=.471, p<.001), and burnout (r=.411, p<.001). In the multiple regression, job stress (${\beta}=.290$, p<.001), burnout (${\beta}=.239$, p<.001), type of employment (${\beta}=.185$, p<.001), and emotional labor (${\beta}=.157$, p=.017) were identified as factors influencing the turnover intention. These factors explained 32.6% of the total variance in the turnover intention. Based on the results, in order to reduce the turnover intention, the improvement of work environment and clear job-descriptions are needed to reduce the job stress, and the development and implementation of proactive psycho-social interventions are necessary to reduce burnout and emotional labor in care workers at long-term care hospitals.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.275-284
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• 2019

This study was conducted to evaluate the health promotion behavior level, health beliefs, and self-efficacy of individuals preparing for civil service examinations, as well as the main factors that influence their health promotion behavior. The study subjects were 290 individuals who were preparing for civil service examinations in Noryangjin, where there are a lot of private institutions that provide training for the examinations. Data were collected by questionnaire surveys conducted from December 1 to 19, 2017. With the use of SPSS ver. 23, descriptive statistics, t-tests, one-way ANOVA, correlation analysis, and stepwise multiple regression were conducted. On average, the score for health promotion behavior practice was $2.37{\pm}0.45points$, health beliefs $3.13{\pm}0.45points$, and self-efficacy $3.55{\pm}0.74points$. Health promotion behavior was significantly positively correlated with perceived severity and perceived benefits, which are sub factors of health beliefs (r=.60, p<.001; r=.55, p<.001), while it was significantly negatively correlated with perceived barriers, which are a sub factor of health beliefs (r=.32, p<.001). The factors that influenced health promotion behavior were perceived health condition and perceived barriers, and the explanatory power of health promotion behavior was 25.1% (F=13.58, p<.001). In general, respondents studied for the examinations for a long time and were under severe job pressure; accordingly, they need to have quality meals, regular exercise, and regular medical check-ups to enhance health promotion behavior to control their stress.

• Women's Health Nursing
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• v.29 no.4
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• pp.274-290
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• 2023

Purpose: This study investigated the effects of prenatal education characteristics, pandemic-related pregnancy stress, and health behaviors during pregnancy on prenatal depression in pregnant women during the coronavirus disease 2019 (COVID-19) pandemic. Methods: The participants were 180 pregnant Korean women, recruited from internet communities for pregnancy preparation, childbirth, and childcare, from July 5 to 15, 2022. The collected data were analyzed using the t-test, analysis of variance, the Mann-Whitney U-test, the Kruskal-Wallis test, and multiple regression analysis. Results: The scores for pandemic-related pregnancy stress (24.50±6.37) and health behaviors during pregnancy (67.07±9.20) were high. Nearly half of the participants (n=89, 49.4%) presented with prenatal depression, with scores of 10 or greater. Prenatal depression had a positive correlation with gestational age (r=.18, p=.019) and pandemic-related pregnancy stress (r=.27, p<.001), and a negative correlation with health behaviors during pregnancy (r=-.42, p<.001). The factors associated with prenatal depression were pandemic-related pregnancy stress (t=4.70, p<.001), marital satisfaction (dissatisfied) (t=3.66, p<.001), pregnancy healthcare practice behaviors (t=-3.31, p=.001), family type (weekend couple) (t=2.84, p=.005), and gestational age (t=2.32, p=.022). The explanatory power of these variables was 38.2%. Conclusion: Since participants had a high level of prenatal depression during the pandemic, and infectious diseases such as COVID-19 may recur, strategies should be developed to improve pregnant women's mental health with consideration of the unique variables that are relevant in a pandemic. It is also necessary to develop efficient online prenatal education programs that can be implemented even in special circumstances such as social distancing, and to evaluate their effectiveness.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.1
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• pp.33-46
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• 2010

We investigated and estimated at the characteristics of decomposition and by-products of N-Nitrosodimethylamine (NDMA) using a design of experiment (DOE) based on the Box-Behken design in an UV process, and also the main factors (variables) with UV intensity($X_2$) (range: $1.5{\sim}4.5\;mW/cm^2$), NDMA concentration ($X_2$) (range: 100~300 uM) and pH ($X_2$) (rang: 3~9) which consisted of 3 levels in each factor and 4 responses ($Y_1$ (% of NDMA removal), $Y_2$ (dimethylamine (DMA) reformation (uM)), $Y_3$ (dimethylformamide (DMF) reformation (uM), $Y_4$ ($NO_2$-N reformation (uM)) were set up to estimate the prediction model and the optimization conditions. The results of prediction model and optimization point using the canonical analysis in order to obtain the optimal operation conditions were $Y_1$ [% of NDMA removal] = $117+21X_1-0.3X_2-17.2X_3+{2.43X_1}^2+{0.001X_2}^2+{3.2X_3}^2-0.08X_1X_2-1.6X_1X_3-0.05X_2X_3$ ($R^2$= 96%, Adjusted $R^2$ = 88%) and 99.3% ($X_1:\;4.5\;mW/cm^2$, $X_2:\;190\;uM$, $X_3:\;3.2$), $Y_2$ [DMA conc] = $-101+18.5X_1+0.4X_2+21X_3-{3.3X_1}^2-{0.01X_2}^2-{1.5X_3}^2-0.01X_1X_2+0.07X_1X_3-0.01X_2X_3$ ($R^2$= 99.4%, 수정 $R^2$ = 95.7%) and 35.2 uM ($X_1$: 3 $mW/cm^2$, $X_2$: 220 uM, $X_3$: 6.3), $Y_3$ [DMF conc] = $-6.2+0.2X_1+0.02X_2+2X_3-0.26X_1^2-0.01X_2^2-0.2X_3^2-0.004X_1X_2+0.1X_1X_3-0.02X_2X_3$ ($R^2$= 98%, Adjusted $R^2$ = 94.4%) and 3.7 uM ($X_1:\;4.5\;$mW/cm^2$, $X_2:\;290\;uM$, $X_3:\;6.2$) and $Y_4$ [$NO_2$-N conc] = $-25+12.2X_1+0.15X_2+7.8X_3+{1.1X_1}^2+{0.001X_2}^2-{0.34X_3}^2+0.01X_1X_2+0.08X_1X_3-3.4X_2X_3$ ($R^2$= 98.5%, Adjusted $R^2$ = 95.7%) and 74.5 uM ($X_1:\;4.5\;mW/cm^2$, $X_2:\;220\;uM$, $X_3:\;3.1$). This study has demonstrated that the response surface methodology and the Box-Behnken statistical experiment design can provide statistically reliable results for decomposition and by-products of NDMA by the UV photolysis and also for determination of optimum conditions. Predictions obtained from the response functions were in good agreement with the experimental results indicating the reliability of the methodology used.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.2
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• pp.167-175
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• 2016

In this study, we estimate air pollutants emission from agricultural waste burning. We investigated activities related to agricultural waste burning such as crop burning rates, location, and time by region. The average crop burning rates per square meter farmland of fruits, pulses, barleys, cereals, vegetables, and special crops were $273.1g/m^2$, $105.7g/m^2$, $7.4g/m^2$, $121.0g/m^2$, $290.7g/m^2$, and $392.9g/m^2$, respectively. We estimated air pollutants emissions with pre-developed emission factors. The estimated air pollutant emission of agricultural biomass burning were CO 148,028 ton/year, $NO_x$ 5,220 ton/year, $SO_x$ 11 ton/year, VOC 59,767 ton/year, TSP 21,548 ton/year, $PM_{10}$ 8,909 ton/year, $PM_{2.5}$ 7,405 ton/year, and $NH_3$ 5 ton/year. When these results compared with the entire emissions of national inventory (CAPSS), CO, VOC, $PM_{10}$ account for about 17.8%, 6.2%, 6.7% of the total, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.385-390
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• 1999

HPLC method usually has been used for the determination of ATP and its related compounds in fish muscle and fish sauce. But, total amount of ATP related compounds in fish sauce is determined less than that of fish muscle. In order to establish the extract analysis method for ATP related compounds in fish sauce, a new enzymatic method was developed and compared with existing HPLC method. Fish sauce was extracted with chilled perchloric acid and neutralized to Ph 7.0 with potassium hydroxide solution, the extract was used as sample analyzed by HPLC as usual. On the other hand, for sample analyzed by enzymatic method, 1 ml extract solution was pipetted into test tube. To the tube, 0.5ml of mixed suspension adenosinedeaminase (4U), nucleosidephosphorylase (0.02U) and xanthineoxidase (0.03U) suspended in 2.0ml of 1/15 M sodium phosphate buffer solution pH 7.6 and 1.5ml deionized water wereadded for the decomposition of IMP, HxR and Hx to uric acid at $37^{\circ}C$ for 40 minutes. Total uric acid was determined by measuring optical density at 290nm. In HPLC method, salt decreased the total amount of ATP related compounds by $13.6\~16.2\%$ at $2.5\%$ concentration, but no effect in enzymatic method. IMP, HxR and Hx were detected at 254nm, while uric acid at only 290nm. The ratio of the total amount of ATP related compounds by HPLC method was about $45\%$ of that by enzymatic method in fish sauce. Form these results, enzymatic method is more accurate and simple than HPLC method for analysis of ATP related compounds in fish sauce.