• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.4
• /
• pp.367-377
• /
• 2021

This study examined the relationship between social support and the subjective well-being of the elderly living in urban areas. The study subjects were 382 elderly people aged 65 or older living in D metropolitan city. The survey was conducted through a personal interview by investigators who visited the study subjects using a structured questionnaire from May 1 to June 30, 2019. As a result, the subjective well-being of the study subjects differed significantly depending on various variables in the sociodemographic, health condition and, health-related behavior characteristics. The subjective well-being according to social support was significantly lower for the groups with lower social support. The correlation of subjective well-being and social support showed a significant positive correlation. Logistic regression showed that the risk of lower subjective well-being increased significantly in the group (Q1), where the total score of social support was very high (Q4). The above results suggest that the subjective well-being of the elderly living in urban areas was not only related to various variables in sociodemographic, health condition, and health-related behavior characteristics but also has significant relationships for social support. Therefore, it is necessary to develop detailed social support practices to improve the subjective well-being.

• Safety and Health at Work
• /
• v.10 no.2
• /
• pp.229-236
• /
• 2019

Background: Emerging reports suggest the potential for adverse health effects from exposure to emissions from some additive manufacturing (AM) processes. There is a paucity of real-world data on emissions from AM machines in industrial workplaces and personal exposures among AM operators. Methods: Airborne particle and organic chemical emissions and personal exposures were characterized using real-time and time-integrated sampling techniques in four manufacturing facilities using industrial-scale material extrusion and material jetting AM processes. Results: Using a condensation nuclei counter, number-based particle emission rates (ERs) (number/min) from material extrusion AM machines ranged from $4.1{\times}10^{10}$ (Ultem filament) to $2.2{\times}10^{11}$ [acrylonitrile butadiene styrene and polycarbonate filaments). For these same machines, total volatile organic compound ERs (${\mu}g/min$) ranged from $1.9{\times}10^4$ (acrylonitrile butadiene styrene and polycarbonate) to $9.4{\times}10^4$ (Ultem). For the material jetting machines, the number-based particle ER was higher when the lid was open ($2.3{\times}10^{10}number/min$) than when the lid was closed ($1.5-5.5{\times}10^9number/min$); total volatile organic compound ERs were similar regardless of the lid position. Low levels of acetone, benzene, toluene, and m,p-xylene were common to both AM processes. Carbonyl compounds were detected; however, none were specifically attributed to the AM processes. Personal exposures to metals (aluminum and iron) and eight volatile organic compounds were all below National Institute for Occupational Safety and Health (NIOSH)-recommended exposure levels. Conclusion: Industrial-scale AM machines using thermoplastics and resins released particles and organic vapors into workplace air. More research is needed to understand factors influencing real-world industrial-scale AM process emissions and exposures.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.5
• /
• pp.411-422
• /
• 2021

The purpose of this study is to examine the relationships between quality of life and demographic characteristics and health-related behavioral characteristics, and their relevance to variables that represent health conditions among metropolitan-dwelling older adults. The study subjects were 380 senior citizens aged 65 or older living in the D metropolitan area, and data collection was conducted by visiting them for interviews in June 2019. A binomial logistic regression analysis was performed to examine the relationship between independent variables (demographic characteristics, health-related behavioral characteristics, health condition variables) and the dependent variable (quality of life) while controlling for gender and age. As a result, the factors related to quality of life for those surveyed were education level, spousal status, living status, bear for living expenses, average monthly allowance, satisfaction with daily life, evaluation of sleep quality, smoking and eating habits, amount of regular exercise, hobbies, subjective health status, physical disability (if any), hearing ability, visual acuity, mastication ability, urinary incontinence (present or not), and amnesia. The above results suggest that quality of life for the elderly living in urban areas is significantly related to variables that indicate demographic characteristics, health-related behavioral characteristics, and health condition.

• Journal of Life Science
• /
• v.33 no.1
• /
• pp.8-14
• /
• 2023

Peroxidasin (PXDN), a multidomain heme peroxidase containing extracellular matrix (ECM) motifs, as well as a catalytic domain, catalyzes the sulfilimine crosslink of collagen IV (Col IV) to reinforce Col IV scaffolds. We previously reported that PXDN is required for endothelial cell (EC) survival and growth signaling through sulfilimine crosslink-dependent matrix assembly. In this study, we examined whether peroxidase activity is required for PXDN function in ECs. First, we constructed a mutant PXDN by point mutation of two highly conserved amino acids, Q823 and D826, which are present in the active site of the peroxidase domain. After isolation of HEK293 clones highly expressing the mutant protein, conditioned medium (CM) was obtained after incubating the cells in serum-free medium for 24 hours and then analyzed by Western blot analysis under nonreducing conditions. The results revealed that the mutant PXDN formed a trimer and that it was cleaved by proprotein convertase-like wild-type (WT) PXDN. However, peroxidase activity was not detected in the CM containing the mutant PXDN, in contrast to that of WT PXDN. In addition, the sulfilimine crosslink ability of the mutant PXDN was lost. Moreover, the CM containing the mutant PXDN failed to promote the growth of PXDN-depleted ECs, unlike the CM containing WT PXDN. These results suggest that the peroxidase activity of PXDN affects EC growth by forming a sulfilimine crosslink.

• Journal of Ginseng Research
• /
• v.48 no.3
• /
• pp.333-340
• /
• 2024

Background: Korean red ginseng (KRG) is a product from ginseng roots, which is enriched with ginsenosides and has been utilized for a long time as an adaptogen to alleviate various physiological or disease conditions. While KRG is generally considered safe, conducting a thorough toxicological assessment of the spray-dried powder G1899 during the juvenile period is essential to establish its safety profile. This study aimed to assess the safety of G1899 during the juvenile period using Sprague-Dawley rats. Methods: Two studies were conducted separately: a juvenile toxicity study and a uterotrophic bioassay. To assess the potential toxicity at systemic, postnatal developmental, and reproductive levels, G1899 was orally gavaged once a day in post-weaning juvenile Sprague-Dawley (SD) rats at 0, 1250, 2500, or 5000 mg/kg/day. Estrogenicity was assessed by orally gavaging G1899 in immature female SD rats at 0, 2500, or 5000 mg/kg/day on postnatal days (PND) 19-21, followed by a uterotrophic bioassay. These studies were conducted in accordance with the Good Laboratory Practice (GLP) regulations and regulatory test guidelines. Results: Regarding juvenile toxicity, no abnormalities related to the G1899 treatment were observed in any group during the experiment. Moreover, no uterotrophic responses were observed in the dosed female group. Based on these results, the no observed adverse effect level (NOAEL) of G1899 was determined to be at least 5000 mg/kg/day for general systemic function, developmental/reproductive function, and estrogenic activity. Conclusion: Our results suggest that G1899 is not toxic to juveniles at doses of up to 5000 mg/kg/day.

• Journal of Animal Science and Technology
• /
• v.49 no.1
• /
• pp.9-14
• /
• 2007

Data of 369 commercial pigs produced from YorkshrexLancrace (YL F1) sows crossed with either Duroc (D), Berkshire (B) or BerkshirexDuroc(BD F1) as a terminal sire were used for the comparison of carcass garde and real retail cut yield. The crosses were performed between May, 2004 and May, 2006 at three interrlated farms belonging to the Gyeongam pork brand. The average carcass weight, carcass backfat thickness, carcass rate, AB grade ratio, lean meat yield were 84.78±0.33kg, 20.72±0.237mm, 76.25±0.208%, 85.7% and 44.30±0.158%, respectively. The average weights of real retail cut were 10.32±0.062kg belly, 4.17±0.025kg boston butt, 3.88±0.022kg rib, 8.40±0.040kg picnic, 15.15±0.081kg ham, 6.44±0.043kg loin and 0.94±0.006kg tender loin. In comparisons of carcass traits among cross types, carcass weights and backfat thicknesses of YL(♀)×B(♂), YL(♀)×BD(♂) and YL(♀)×D(♂) were 85.73±0.516kg, 82.69±0.788kg and 84.79±0.603kg, respectively and 22.09±0.356mm, 20.33±0.543mm and 19.58±0.415mm, respectively. The YL(♀)×B(♂) cross showed the highest carcass weight and backfat thickness. The ratio of AB grade were 0.83±0.030% in YL(♀)×B(♂), 0.97±0.046% in YL(♀)×BD(♂) and 0.83±0.035% in YL(♀)×D(♂), and the YL(♀)×BD(♂) was higher than other two crosses. Weights of belly were 10.28±0.092kg in YL(♀)×B(♂), 10.59±0.133kg in YL(♀)×BD(♂) and 10.25±0.107kg in YL(♀)×D(♂). Consequently, the YL(♀)×BD(♂) cross showed the highest yield. In conclusion, there was no difference in carcass yield of commercial pigs derived from BD (F1) terminal sires with those from D terminal sires. However, weight of belly and AB grade ratio from BD (F1) terminal sires are higher than two others. Therefore, BD (F1) sire could be utilized as terminal one and contribute better profit for the pig industry.

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

• Journal of Environmental Health Sciences
• /
• v.37 no.4
• /
• pp.267-278
• /
• 2011

Objectives: A great number of hazardous agents can be emitted from various types of art-creation in a fine arts college, but little data on exposure assessment has been published. A variety of processes encompassing toxic or non-toxic materials, tools, and components are involved in a sculptor work at a fine art college. The aim of this study was to assess exposure levels to particulates and noise during sculpture classes in a college of fine arts. Methods: Students in sculpture classes participated in this study. Mass, number, and surface area concentrations of particulates, noise level, temperature and relative humidity were monitored by both personal and area sampling during the tasks of metal, wood, and stone sculpting. Results: The number and surface concentration of particulates was the highest in the task of wood sculpting, followed by metal and stone work. The mass concentration of particulates was the highest in stone sculpting (personal GM 3.0 mg/$m^3$, GSD 3.0), followed by wood (personal GM 1.5 mg/$m^3$, GSD 1.8) and metal work (personal GM 0.95 mg/$m^3$, GSD 1.51) in that order. Occupational exposure limits (OEL) for particulates depends on the type of particulate. For wood dust, 86% (six subjects) of the personal samples and all area samples exceeded the Korean OEL for wood dust (1 mg/$m^3$), while 20% (two subjects) among stone sculpting students were exposed above the Korean OEL (10 mg/$m^3$). In contrast, metal sculpting did not exceed the OEL (5 mg/$m^3$). For noise level, metal sculpting students (Leq 95.1 dB(A) in the morning, 85.3 dB(A) in the afternoon) were exposed the most, followed by stone sculpting (88.3 dB(A)), and wood sculpting (84.8 dB(A)) in that order. Compared with the 90 dB(A) of the Korean OEL and 85 dB(A) of the American Conference of Governmental Industrial Hygienists' threshold limit value (ACGIH-TLV) for noise, 100% of the subjects (five subjects) and area samples during metal sculpting in the morning session exceeded both OELs, but only three subjects (60%) exceeded the ACGIH-TLV in the afternoon session. For stone sculpting, 50% (one subject) and 100% (two subjects) exceeded the Korean OEL and ACGIH-TLV, respectively, but the area sample did not exceed either OEL. During wood sculpting, two subjects (40%) exceeded ACGIH TLV. Conclusions: This work evaluated the sculptors' exposure to particulate matter and noise in fine art college, and revealed a poor working environment for the participating students. Effective measures should be supplemented by the administration of colleges.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.20 no.5
• /
• pp.855-867
• /
• 2018

When a weak zone exists ahead of tunnel face, the stress in the adjacent area would increase due to the longitudinal arching effect and the stability of the tunnel is affected. Therefore, it is critical to prepare a countermeasure through the investigation of the frontal weakness zone of the excavated face. Although there are several researches to predict the existence of weak zone ahead of tunnel face, such as geophysical exploration, numerical analysis and tunnel support, lack of studies on the relaxation zone depending on the width or distance from the vulnerable area. In this study, the impact of the weak zone on the formation of the relaxation zone was investigated. For this purpose, a series of laboratory test were carried out varying the width of the weak zone and the separation distance between tunnel face and weak zone. In the model test, sand with a water content of 3.8% was used to form a model ground. The model weak zone was constructed with dry sand curtains. The tunnel face was adjusted to allow a sequential excavation of upper and lower half part. load cells were installed on the bottom of the foundation and the tunnel face and measuring instruments for displacement were installed on the surface of the model ground to measure the vertical stress and surface displacements due to tunnel excavation respectively. The test results show that the width of weak zone did not affect the ground settlement while the ground subsidence drastically increased within 0.25D. The vertical stress and horizontal stress increased from 0.5D or less. In addition, the longitudinal arching effect is likely within the 1.0D zone ahead of the tunnel face, which may reduce the vertical stress in the ground following tunneling direction.

• Journal of Nutrition and Health
• /
• v.50 no.3
• /
• pp.246-256
• /
• 2017

Purpose: This study aimed to investigate the association of total dietary antioxidant capacity (TAC) with oxidative stress and metabolic markers among patients with metabolic syndrome according to gender. Methods: A total of 346 subjects aged 30~59 years with two or more risk factors of metabolic syndrome were recruited from a general hospital near Seoul in South Korea between 2010 and 2012 based on data from the medical checkup. Biochemical indices for oxidative stress and metabolic markers were measured. Food consumption data from 3-day food records were linked with the antioxidant capacity database for commonly consumed Korean foods to estimate individual's TAC. Results: Average dietary TAC of the study subjects was 132.0 mg VCE/d/1,000 kcal in men and 196.4 mg VCE/d/1,000 kcal in women. Levels of ${\gamma}$-glutamyltransferase (GGT), systolic blood pressure, diastolic blood pressure, and blood triglycerides were reduced significantly according to increasing TAC in men, but there was no significant trend in women. Intakes of total flavonoids and carotenoids were significantly negatively correlated with GGT (p < 0.05) and d-ROMs (p < 0.01) in men, whereas those of ${\alpha}$-tocopherol (p < 0.05) and ${\gamma}$-tocopherol (p < 0.05) were positively correlated with biological antioxidant potential (BAP) in women. The odds ratio of high oxidative stress indices and abnormal metabolic markers according to TAC level were not significant in either men or women. Conclusion: The results show that dietary TAC was partially associated with oxidative stress and metabolic markers among patients with metabolic syndrome. Further research is required for elucidating the association between dietary TAC and incidence of metabolic syndrome and chronic diseases within a large population in prospective studies.