• Journal of the Korean society of biological therapies in psychiatry
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• v.24 no.3
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• pp.129-141
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• 2018

Suicide is a behavior that is intended to cause death by itself and requires medical treatment, resulting in suicidal attempt or completion. Suicide causes loss of life, damages the body, costs a lot of medical expenses, and causes families to fall into sorrow and suffering therefore this suicide is a huge loss to family and society. There have been attempts to reduce and prevent suicide by understanding the mechanism of suicide. The mechanism of suicide can be thought of as psychological mechanism and biological mechanism. In the past, if we considered the psychological and biological mechanisms separately, the development of neuroscience now connects and integrates these two. Psychological factors affect biological factors and biological temperaments also affect perception or thinking about the situation and increase psychological vulnerability. Distant factors in suicidal behavior-such as childhood adversity and family and genetic predisposition-increase the lifetime risk of suicide. They alter the response to stress and other processes through changes in gene expression and regulation of emotional and behavioral characteristics. Distant factors affect the biological system and consequently changes in these systems can increase the risk of suicide. In other words, the distal factor does not directly induce suicidal behavior but rather acts indirectly through developmental or mediating factors. These mediating factors are impulsive aggressive and anxious trait, and chronic use of substances. The mechanism of this disorder is the abnormality of the serotonin system and the abnormality of the lipid level. Proximal factors are associated with the onset of suicide events and include changes in the major neurotransmitter systems, inflammatory changes, and dysfunction of glial cells in the brain. A series of studies, including a variety of research methods and postmortem and in-vivo imaging studies, show the impairment of the serotonergic neurotransmitter system and hypothalamic-pituitary-adrenal axis stress response system for suicidal behavior. These disorders lead to suicidal behavior due to difficulty in cognitive control of mood, pessimism, reactive aggression, abnormality in problem solving abilities, excessive response to negative social signals, severe emotional distress, and cognitive dysregulation of suicidal ideation.

• Journal of Korean Society on Water Environment
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• v.27 no.2
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• pp.218-227
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• 2011

The objective approach for assessment of stream naturalness is an essential part of the stream restoration project. This study proposes the methodology for the assessment of stream naturalness considering physical, biological and chemical factors. Physical factors consists of riffle and pool, river bed material, bank protection, floodplain vegetation and levee materials; biological factors are benthic macroinvertebrate, KSI (Korean Saprobic Index), and IBI (Index of Biological Integrity) and chemical factors are pH, DO (dissolved oxygen), and TP (total phosphorus). This procedure is applied to the Mokgamcheon. As a result, the downstream of Mokgamcheon (zone I) needs the prompt improvement of stream naturalness, compared to the others (zone II and III). This evaluation technique will be an effective tool to quantify the stream naturalness and can be used to set the target of stream restoration project.

• Safety and Health at Work
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• v.5 no.2
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• pp.43-52
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• 2014

Because information on biological agents in the workplace is lacking, biological hazard analyses at the workplace to securely recognize the harmful factors with biological basis are desperately needed. This review concentrates on literatures published after 2010 that attempted to detect biological hazards to humans, especially workers, and the efforts to protect them against these factors. It is important to improve the current understanding of the health hazards caused by biological factors at the workplace. In addition, this review briefly describes these factors and provides some examples of their adverse health effects. It also reviews risk assessments, protection with personal protective equipment, prevention with training of workers, regulations, as well as vaccinations.

• Journal of Nutrition and Health
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• v.28 no.4
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• pp.331-344
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• 1995

The process of breast feeding was investigated from the 36th week of pregnancy to 12 weeks postnatal, in order to analyze the factors affecting breast feeding duration and provide the basic data on an education program for successful breast feeding. The general characteristics of study group had no marked effects on the breastfeeding duration. The young and highly condition during pregnancy and the degree of morning sickness affected the practice of breastfeeding. In the study of prenatal sociobehavioral factors, intended duration affected the breastfeeding duration, and the maternal perception that breastfeeding is good for weight loss after delivery as well as infant formula milk is not as good as breast milk, led to successful breast feeding. Among the postnatal biological factors, the duration of gestation affected the breast feeding. Among the postnatal biological factors, the duration of gestation affected the breastiffeding outcome. In the case of early parturition, breastfeeding rate was low. Among the postnatal biocultural factors, time of first feed, milk volume and maternal perception of infant's sucking ability affected the bresatfeeding duration. From these result, it is suggested that an education program such as participation of nursing class to the pregnant women should be provided for successful breastfeeding.

• Journal of Ecology and Environment
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• v.48 no.3
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• pp.247-255
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• 2024

Background: To effectively understand and evaluate plant diversity in a specific area and make meaningful comparisons between regions, standardized methods that measure diversity irrespective of survey plot size are crucial. This study proposes a model equation for comparing plant species diversity using the modified Whittaker plots. Plant species diversity was measured in two Gotjawal areas on Jeju Island, where the coexistence of northern and southern limit species significantly impacts diversity. By analyzing the relationship between plant species diversity and environmental factors, the study clarified the characteristics of plant and habitat diversity in the Gotjawal ecosystem. Results: The species richness of vascular plants, herbaceous plants, and woody plants increased with area and was higher in Jeoji Gotjawal than in Seonheul Gotjawal. Similarly, the species turnover rate (slope value) was higher in Jeoji Gotjawal (4.37) than in Seonheul Gotjawal (3.85). This indicates that the species richness in Jeoji Gotjawal increases more with the expansion of the survey area (1-1,000 m²), reflecting a faster species turnover rate. Additionally, in Gotjawal areas, species richness increased with greater leaf litter depth, elevation, slope, and rock ratio. These results indicate that differences in plant species diversity were attributed to soil environmental factors. Conclusions: The plant species diversity of Gotjawal, surveyed using standardized methods, was lower than that of forested areas in the central region of South Korea where the same method was applied. Most previous studies on species diversity likely compared diversity without considering a consistent survey area. Therefore, when comparing plant species diversity domestically and globally, it emphasizes the need for the use of standardized survey methods.

• Molecules and Cells
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• v.38 no.8
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• pp.677-684
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• 2015

Osteoarthritis (OA) is one of the most prevalent forms of joint disorder, associated with a tremendous socioeconomic burden worldwide. Various non-genetic and lifestyle-related factors such as aging and obesity have been recognized as major risk factors for OA, underscoring the potential role for epigenetic regulation in the pathogenesis of the disease. OA-associated epigenetic aberrations have been noted at the level of DNA methylation and histone modification in chondrocytes. These epigenetic regulations are implicated in driving an imbalance between the expression of catabolic and anabolic factors, leading eventually to osteoarthritic cartilage destruction. Cellular senescence and metabolic abnormalities driven by OA-associated risk factors appear to accompany epigenetic drifts in chondrocytes. Notably, molecular events associated with metabolic disorders influence epigenetic regulation in chondrocytes, supporting the notion that OA is a metabolic disease. Here, we review accumulating evidence supporting a role for epigenetics in the regulation of cartilage homeostasis and OA pathogenesis.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.3
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• pp.292-298
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• 2020

Objectives: The aim of this research is to establish Similar Exposure Groups (SEGs) for chemical and biological risk factors that occur in farm work involving 24 tasks among 15 crops. Methods: To categorize SEGs, work type, work environment, and similar tasks for each crop were considered. After confirming the chemical risk factors (pesticides, inorganic dust-total dust and PM₁₀, ammonia, and hydrogen sulfide) and biological factors (organic dust-total dust and PM₁₀, and endotoxins) that occur in the crops and tasks, similar crops and tasks were selected as SEGs. Results: Among chemical risk factors, pesticides was selected for the SEGs, which was categorized by open field, greenhouse, fruit, and specialty crops. For inorganic dust, open field (plowing harrowing, seedling, planting, harvest, and sorting and packing) and specialty crops (plowing harrowing, seedling, planting, and harvest) were selected as SEGs. For ammonia and hydrogen sulfide, livestock (preparation of farm, management of nursery bed, feeding, shipment and manure treatment) were selected as SEGs. For biological risk factors such as organic dust (total dust, PM₁₀) and endotoxins, open field (manure application), greenhouse (plowing harrowing, planting, manure application, and harvest), fruit (manure application), specialty crops (manure application, making furrows, mixing mushroom media, harvest, and sorting and packing), and livestock (preparation of farm, maintaining poultry litter, feeding, shipment and manure treatment) were selected as SEGs. Conclusions: To establish similar exposure groups in agriculture, it is important that the characteristics of each hazard factor are categorized by identifying risk factors occurring by tasks.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.15 no.1
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• pp.13-18
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• 2012

The pathogenesis of inflammatory bowel diseases is not very well understood; it is currently thought to be caused by the interaction between genetic factors, environmental factors, intestinal microbes, and immune factors. Biological agents such as anti-tumor necrosis factor (anti-TNF) are widely being used as therapeutic agents. Infliximab, a chimeric monoclonal IgG1 antibody against tumor necrosis factor, has been demonstrated to have an effect in the induction and maintenance of remission in Crohn's disease in children. The effects of biological agents, typified by anti-TNFs, in inflammatory bowel disease in children; the recent concern on the administration of biological agents in combination with immunomodulators; and 'Top-down' therapy are some of the topics covered in this review.

• Journal of Microbiology
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• v.41 no.2
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• pp.137-143
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• 2003

The present study was performed to identify pathogenic factors of Chlamydia trachomatis, which invade the host cell membrane. We prepared monoclonal antibody against C. trachomatis and searched for pathogenic factors using this antibody, and subsequently identified the surface components of the elementary body of C. trachomatis, i.e., major outer membrane protein (MOMP), lipopolysaccharide (LPS), and two other surface exposure proteins. These proteins are believed to be important in the pathogenesis of host cell chlamydial infection. Additionally, to identify factors related to the host cell and C. trachomatis, we prepared C. trachomatis infected and non-infected McCoy cell extracts, and reacted these with anti-chlamydial LPS monoclonal antibody. We found that anti-chlamydial LPS monoclonal antibody reacted with a 116 kDa proteinaceous McCoy cell membrane component.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.5
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• pp.350-354
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• 2000

The growth promotion of a Taxus brevifolia cell suspension culture was investigated using conditioning factors. The conditioning factors produced and secreted from cultured cells usually stimulate cell division and the production of secondary metabolites. Therefore, the effective incubation time for the optimal secretion of conditioning factors was firstly determined for the promotion of cell growth. Conditioned media obtained by cultivating for 2 and 5 days showed the promotion of initial cell growth during the early cell growth period. However, the positive effect of the conditioning factors on the initial cell growth did not continue because of the depletion of the medium nutrients. Accordingly, the addition of a carbon source to the conditioned medium prolonged the positive effect on the cell growth. The addition of sucrose to the conditioned medium resulted in the maximum cell density being reached 4 days earlier compared to the control group and an increased substrate yield.