• Journal of Life Science
• /
• v.33 no.8
• /
• pp.639-650
• /
• 2023

The levels of harmful components in aerosols from heated tobacco products (HTPs) have been reported to be significantly lower than in cigarette smoke. However, it remains unclear whether the use of HTPs can mitigate the cardiovascular risks associated with cigarette smoking (CS). The objective of this study was to investigate the effects of a short-term switch from CS to HTP use on cardiac autonomic regulation (CAR). Seven healthy male smokers completed an open-label, randomized, cross-over trial consisting of five days of CS, use of three different HTPs (IQOS use, IQ; lil SOLID use, LS; lil HYBRID use, LH), or non-smoking (NS). Each session was separated by a one-week washout period, and levels of exhaled carbon monoxide (CO) and carboxyhemoglobin (COHb), systolic (SBP) and diastolic blood pressure (DBP), and heart rate variability (HRV) reflecting CAR were assessed before use of the product assigned to each session and at 24, 48, 72, 96, and 120 hr after use. Levels of exhaled CO and COHb were statistically significantly reduced only during NS. There were no statistical changes in SBP and DBP within any session. However, in HRV spectral analysis, log-transformed high frequency (lnHF) increased statistically significantly in IQ, LS, and NS, respectively. Normalized HF (HFnu) was significantly increased in NS and LH, respectively. lnHF and HFnu showed significant interaction effects. The findings of this study suggest that a short-term switch to HTPs instead of CS may lead to different distribution patterns of CAR, primarily driven by enhanced cardiac vagal tone.

• Journal of recreation and landscape
• /
• v.6 no.2
• /
• pp.27-36
• /
• 2012

This study, presents the details of a propulsion system for a systematic approach to the remodeling of rural villages as part of the pilot project that will be implemented in 2013. Studies on remodeling rural villages have focused mainly on various concepts of remodeling purposes and functions, and on the size and allocation standards of the facilities, such as rural houses, village rest areas, or public facilities. Thus, research is required on the establishment of a plan to restructure rural spaces and suggestions regarding the standards applicable at the local sites. This study employed an upward access system to prepare for the remodeling project and encourage the local residents' participation. As a result, the local residents voluntarily participated in drawing up a comprehensive plan for the village maintenance settings and forms, and for making the arrangements, by discussing the pros and cons of the plan, or through the forum. Based on this result, the local government examined the project in terms of its specifics, size, timing, budgetary appropriation, and anticipated results in order to implement the project, and also provided aid from the field experts to review the plan for the space and facility plans, and the legal system to establish the remodeling plan for the rural villages. Thus, this study attempts to contribute toward improving the quality of the rural villager's lives through a comprehensive remodeling of the whole rural village, not through an individual remodeling method.

• Nuclear Engineering and Technology
• /
• v.26 no.3
• /
• pp.337-344
• /
• 1994

Enthalpy rise hot channel factor($F_{\Delta{H}}$$^{N}$) is one of the most limiting constraints in determining the fuel loading pattern(LP) for PWR's. In order to enhance the LP design flexibility without any changes of not only basic fuel specifications but also Technical Specifications and Operation Procedures, we apply the enrichment zoning concept to Westinghouse designed PWR's to flatten the rod power distributions within the fuel assembly and thus to reduce $F_{\Delta{H}}$$^{N}$. Enrichment zoning is described that each assembly consists of two different enrichment fuels ; the lower enriched fuels are located in positions which are expected to have the higher rod power and vice versa for the higher enriched fuels. As a result of unit assembly calculations to flatten the rod power distribution within the assembly, the appropriate enrichment difference is found to be 0.3~0.4w/o. Through core depletion calculations for the 18-month cycle of Kori Unit 4, the $F_{\Delta{H}}$$^{N}$ behavior in core with the enrichment zoning concept is investigated. A comparison with the reference case without the enrichment zoning results in a reduction in $F_{\Delta{H}}$$^{N}$ of approximately 1.5%.TEX>H/$^{N}$ of approximately 1.5%.

• Journal of Korean Elementary Science Education
• /
• v.42 no.1
• /
• pp.149-160
• /
• 2023

A Korean-version science curiosity questionnaire (Science Curiosity in Learning Environments [SCILE(15)]) was developed after factor analysis of the Korean-version SCILE(30) questionnaire. Pre-service elementary school teachers were surveyed using the Korean-version SCILE(30), and a factor analysis based on their responses was performed. The factor analysis demonstrated that the Korean-version SCILE(15) consisted of three curiosity factors: a 'science practices' factor, a 'stretching' factor, and an 'embracing' factor. Confirmatory factor analysis of the factor structure revealed correlations between all the factors, thus confirming their commonality as a science curiosity factors. The Cronbach alpha for the reliability of all items in the Korean-version SCILE(15) and of items by factor was greater than 0.700. The Korean-version SCILE(15) was therefore evaluated to be reliable as a science curiosity questionnaire. Pre-service elementary teachers who participated in the survey for the development of the SCILE(15) were aware of the 'science practices', 'stretching', and 'embracing' science curiosity factors. Analysis in a general linear model of the degree of recognition accorded by pre-service elementary teachers to the three science curiosity factors demonstrated significant differences between the curiosity factors in terms of recognition. This cohort of pre-service elementary teachers showed the highest level of recognition of the 'stretching' curiosity factor and the lowest level of recognition of the 'embracing' curiosity factor.

• The Journal of the Korea Contents Association
• /
• v.22 no.8
• /
• pp.347-357
• /
• 2022

This study was attempted to identify the health-related quality of life of Chronic Obstructive Pulmonary Disease (COPD) patients and factors influencing the quality of life, focusing on Health-related quality of life with 8 items (HINT-8). The subjects of this study were 451 adults aged 40 years or older who performed lung function tests and whose ratio is less than 0.7 by measuring forced respiratory volume in 1 second [FEV₁] to forced vital capacity in the 2019 National Health and Nutrition Examination Survey, It was analyzed using SAS program. As a result, both the HINT-8 index and EuroQol five-dimensions 3-level version (EQ-5D-3L) index were appropriate as tools to measure the health-related quality of life in COPD patients, and the factors affecting the health-related quality of life were age, gender, income, and smoking status, comorbidities, stress, and subjective health status. Therefore, in order to improve the health-related quality of life of COPD patients, an individualized management program suitable for the characteristics of subjects such as the low-income class and the elderly, including smoking cessation education and stress management, should be developed and applied.

• Journal of Dairy Science and Biotechnology
• /
• v.41 no.4
• /
• pp.191-202
• /
• 2023

In this study, lactic acid bacteria (LAB) was isolated from blueberries. The isolated LAB were rod-shaped and gram-positive, as shown using gram staining. In addition, the identified bacteria showed high homology to Lactiplantibacillus argentoratensis. The culture supernatant was isolated from L. argentoratensis and its antibacterial activity against the pathogenic bacteria Salmonella and Escherichia was analyzed. Culture supernatants of L. argentoratensis significantly inhibited the growth of Salmonella. Enteritidis NCCP 16947, Salmonella Typhimurium NCCP 16960, and Salmonella. Thompson NCCP 11704. Interestingly, the higher the concentration of the culture supernatant, the more significant was the antibacterial activity. Additionally, the culture supernatant of L. argentoratensis showed significant antibacterial activity against Escherichia strains. To determine whether the antibacterial substance is stable to heat and pH, the LAB culture supernatant was heat-treated under 65℃ for 30 min, 75℃ for 15 min, 85℃ for 10 min, and 100℃ for 5 min. Measurement of antibacterial activity against pathogenic strains by adding 5% of heat-treated culture medium showed the same antibacterial activity as before heat treatment. However, in a test where the pH of the culture supernatant was adjusted to 7.0 from 3.73, no antibacterial activity was observed.

• Korean Journal of Clinical Laboratory Science
• /
• v.56 no.1
• /
• pp.59-65
• /
• 2024

This study examined the fecal samples of striped field mice (Apodemus agrarius coreae) captured in Jeju Special Self-Governing Province. Fecal samples, including the colon and other intestinal organs, were collected and subjected to aerobic culture to investigate the distribution of intestinal microorganisms. Gram staining of the aerobic cultured bacterial colonies from 36 fecal samples revealed the predominant presence of gram-negative bacilli in all samples. Among the 36 samples, gram-negative bacilli were identified in 36 strains (100%), gram-positive cocci in 21 strains (58.3%), and gram-positive bacilli in 15 strains (41.7%), while no gram-negative cocci were observed. The gram-negative bacilli cultured from the 36 samples were identified using the Vitek 2 system, and all were determined to be Escherichia coli (E. coli) strains. In addition, one sample was concurrently identified with E. coli and Enterobacter cloacae strains. The antimicrobial susceptibility testing for the identified E. coli strains did not include all antibiotics, but one strain exhibited intermediate resistance to cefoxitin. No pathogenic bacteria were present in the fecal samples of the scrub typhus-infected rodents, which are vectors for chigger-borne diseases affecting humans and animals.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.44 no.2
• /
• pp.113-117
• /
• 2024

This study was conducted to find a way to improve quality by observing changes in quality and microbial communities according to whether corn silage was treated with additives and the storage period, and to utilize them as basic research results. The experimental design was performed by 2×4 factor desigh, and the untreated (CON), and the additive inoculated (ADD) silage were stored and fermented for 30 (TH), 60 (ST), 90 (NT), and 120 (OHT) days, with each condition repeated 3 times. There was no change in the nutrient content of corn silage according to additive treatment and storage period (p>0.05). However, the change in DM and the increase in the relative proportions of lactic acid content and Lactobacillales according to the storage period (p<0.05) indicate that continuous fermentation progressed until OHT days of fermentation. Enterobacterales (33.0%), Flavobacteriales (14.4%), Sphingobacteriales (12.7%), Burkholderiales (9.28%) and Pseudomonadales (6.18%) dominated before fermentation of corn silage, but after fermentation, the diversity of microorganisms decreased sharply due to the dominance of Lactobacillales (69.4%) and Bacillales (11.5%), Eubacteriales (7.59%). Therefore, silage maintained good fermentation quality with or without microbial additives throughout all fermentation periods, but considering the persistence of fermentation even in long-term storage and the aerobic stability, it would be advantageous to use microbial additives.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.18 no.2
• /
• pp.45-54
• /
• 2010

Field study was conducted for 5 months to investigate the effect of leachate recirculation on aerobic landfill stabilization at active landfilling site. The area of field experiment was $24{\times}24m$ and 9 vertical air injection wells with screen ranging 3~9 m were installed. Aerobic landfill operation for 5 months increased average internal landfill temperature to $70^{\circ}C$ and 8 % of landfill height was settled down. $94m^3$ of leachate was recirculated for 1 month to increase moisture content of landfill to favor microbial degradation of organic matter, which resulted in temporary increase of groundwater level and anaerobic environment. But leachate recirculation triggered increase of internal landfill temperature of neighboring monitoring well. Because excessive leachate recirculation decreased internal landfill temperature by cooling effect, internal landfill temperature should be checked to avoid abrupt decrease of temperature during leachate recirculation. Also, to prevent anaerobic environment, intermittent leachate recirculation was recommended.

• Clinical and Experimental Pediatrics
• /
• v.52 no.11
• /
• pp.1267-1272
• /
• 2009

Purpose:We examined the ability of preschool aged children to meet the American Thoracic Society (ATS) and European Resiratory Society (ERS) goals for spirometry quality and tried to find out the major factor for improving the rate of success of spiromety test in this age group. Methods:Spirometry was performed in 2-6 aged 155 children with chronic cough or suspicious asthma with the recording of maneuver quality measures of forced expiratory time, end-of-test volume, back-extrapolated volume (Vbe), and forced vital capacity (FVC), as well as flow-volume curve. The subjects were tested several times and the two best results in each subject were selected. All criteria for quality control were suggested by ATS/ERS guidelines. The criteria for starting of the test was Vbe <80 mL and Vbe/FVC <12.5%. The criteria for repeatability of the test was that second highest FVC and FEV1 are within 100 ml or 10% of the highest value, whichever is greater. For the criteria for termination of the test for preschool aged children, we evaluated the flow-volume curve Results:As getting older, the success rate of spirometry increased and rapidly increased after 3 years old. Total success rate of the test was 59.4% (2 years old - 14.3%, 3 years old - 53.7%, 4 years old - 65.1%, 5 years old - 69.7%, 6 years old- 70.8%). The percentage of failure to meet the criteria for starting the test was 6.5%, repeatability of the test was 12.3% and end of the test was 31%. There was a significant difference only in age between success group and failure group. Evaluating the quality control criteria of previous studies, the success rate increased with age. Conclusion:About 60% of preschool aged children met ATS/ERS goals for spirometry test performance and the success rate was highly correlated with age. It is clearly needed that developing more feasible and suitable criteria for quality control of spirometry test in preschool aged children.