• The Korean Journal of Physiology and Pharmacology
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• v.2 no.5
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• pp.617-628
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• 1998

In order to understand the pathogenetic mechanism of adult respiratory distress syndrome (ARDS), the role of phospholipase A2 (PLA2) in association with oxidative stress was investigated in rats. $Interleukin-1{\alpha}\;(IL-1,\;50\;{\mu}g/rat)$ was used to induce acute lung injury by neutrophilic respiratory burst. Five hours after IL-1 insufflation into trachea, microvascular integrity was disrupted, and protein leakage into the alveolar lumen was followed. An infiltration of neutrophils was clearly observed after IL-1 treatment. It was the origin of the generation of oxygen radicals causing oxidative stress in the lung. IL-1 increased tumor necrosis factor (TNF) and cytokine-induced neutrophil chemoattractant (CINC) in the bronchoalveolar lavage fluid, but mepacrine, a PLA2 inhibitor, did not change the levels of these cytokines. Although IL-1 increased PLA2 activity time-dependently, mepacrine inhibited the activity almost completely. Activation of PLA2 elevated leukotriene C4 and B4 (LTC4 and LTB4), and 6-keto-prostaglandin $F2{\alpha}\;(6-keto-PGF2{\alpha})$ was consumed completely by respiratory burst induced by IL-1. Mepacrine did not alter these changes in the contents of lipid mediators. To estimate the functional changes of alveolar barrier during the oxidative stress, quantitative changes of pulmonary surfactant, activity of gamma glutamyltransferase (GGT), and ultrastructural changes were examined. IL-1 increased the level of phospholipid in the bronchoalveolar lavage (BAL) fluid, which seemed to be caused by abnormal, pathological release of lamellar bodies into the alveolar lumen. Mepacrine recovered the amount of surfactant up to control level. IL-1 decreased GGT activity, while mepacrine restored it. In ultrastructural study, when treated with IL-1, marked necroses of endothelial cells and type II pneumocytes were observed, while mepacrine inhibited these pathological changes. In histochemical electron microscopy, increased generation of oxidants was identified around neutrophils and in the cytoplasm of type II pneumocytes. Mepacrine reduced the generation of oxidants in the tissue produced by neutrophilic respiratory burst. In immunoelectron microscopic study, PLA2 was identified in the cytoplasm of the type II pneumocytes after IL-1 treatment, but mepacrine diminished PLA2 particles in the cytoplasm of the type II pneumocyte. Based on these experimental results, it is suggested that PLA2 plays a pivotal role in inducing acute lung injury mediated by IL-1 through the oxidative stress by neutrophils. By causing endothelial damage, functional changes of pulmonary surfactant and alveolar type I pneumocyte, oxidative stress disrupts microvascular integrity and alveolar barrier.

• The Korean Journal of Pharmacology
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• v.24 no.2
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• pp.197-201
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• 1988

Effects of high concentration of KC1 and caffeine on cytosolic $Ca^{2+}$ level $([Ca^{2+}]_{cyt})$, measured simultaneously with muscle tension using a fluorescent intracellular $Ca^{2+}$ indicator fura 2, were examined in isolated smooth muscle of rat aorta. High $K^+$ (72.7 mM) solution induced sustained increase in both $([Ca^{2+}]_{cyt})$ and tension. In contrast to this, caffeine (20 mM) induced a rapid increase in $([Ca^{2+}]_{cyt})$ followed by a decrease to a level which was higher than the resting level. However, muscle tension showed only a transient increase followed by a decrease below the resting level. In a $Ca^{2+}-free$ solution, high $K^+-induced$ neither $([Ca^{2+}]_{cyt})$ nor tension, whereas caffeine induced a transient increase in both $([Ca^{2+}]_{cyt})$ and muscle tension. These results suggest that high $K^+-induced$ contraction in vascular smooth muscle of rat aorta is due to $Ca^{2+}$ influx whereas caffeine-induced contraction is due to $Ca^{2+}$ release from cellular store. Further, caffeine seems to have an additional effect to decrease the sensitivity of the contractile elements to $Ca^{2+}$.

• Korean Security Journal
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• no.62
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• pp.113-134
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• 2020

This study was conducted to examine the influence of the psychological health of the released offenders on their adaptation to community. Researchers analyzed the survey data of 216 participants who received joint marriage support from the Korea Legal Protection and Welfare Corporation. The results showed that the education level, marriage status, and monthly income were having a positive influence on the community adaptation of the released offenders, and the higher the depression and inter-personality among the risk factors of psychological health, the more negative the community adaptation. A higher sense of self-esteem, a psychological health protection factor, has a positive effect on community adaptation while reducing the influence of risk factors, depression and inter-personality. In sum, high self-esteem can contribute to increasing social life satisfaction after release from prison, promote risk factors to positive life changes, suppress negative situations and increase the possibility of successful community adaptation. Although this study confirmed that self-esteem is the most important factor among psychological factors for successful community adaptation of inmates, it will require relevant follow-up research and multi-disciplinary support because psychological factors alone cannot solve the problem.

• Journal of Ginseng Research
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• v.33 no.1
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• pp.33-39
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• 2009

The effects of white ginseng and red ginseng ethanol extracts on the proliferation, nitric oxide (NO) production and tumor necrosis factor-$\alpha$ (TNF-$\alpha$) in human Band T lymphocytes isolated from blood cell of sasang constitution were examined in vitro. White ginseng extract known as medicine suitable for soeumin constitution showed the highest immune activities such as proliferation, NO production and TNF-$\alpha$ in soeumin constitution, and followed by taeeumin and soyangin, respectively (P<0.05). However, there were immunologically insignificant differences among sasang constitution lymphocytes treated by red ginseng ethanol extract. Both white and red ginseng ethanol extracts showed significantly higher immunological activities than LPS-induced sasang constitution lymphocytes on NO production and TNF-$\alpha$ release (P<0.05). The different immunological activities of white and red ginseng extracts in sasang constitution lymphocytes might be due to the component changes during the processing of ginseng. Thus, the findings of components suitable for all constitutions from red ginseng extract could be applied as a new constitution marker.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.1
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• pp.8-14
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• 1996

Use of phosphate coated urea to decrease ammonia volatilization from directly seeded paddy under dryland condition at early stage was tested. Effect on urea hydrolysis was investigated through laboratory study comparing with use of thiourea, a urease inhibitor, under different water content. A field measurement of volitilized ammonia with phosphate-glycerol ammonia absorber was conducted for surface treated urea, phosphate coated urea, phosphate coated slow-release fertilizer and organic fertilizer. Through laboratory study, hydrolysis rate of phosphate coated urea at three days after treatment was lower than that of urea, however, the rate after one week was same. Thiourea addition retarted urea hydrolysis. By field measurement, ammonia volatilization was effectively reduced by use of phosphate coated urea.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.4
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• pp.280-291
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• 2007

Much research has been conducted in the field of phytoremediation since the discovery of the range of plants known as hyperaccumulators. Research has focused simultaneously on elucidating the mechanism of metal(loid) accumulation and development of practical techniques to enhance accumulation efficiency. To date, it is generally understood that there are five specific mechanisms employed by hyperaccumulating plant species that are either not or under utilized by non-hyperaccumulators. These include 1) enhanced metal(loid)s uptake through the root cell, 2) enhanced translocation in plant tissue, 3) detoxification and sequestration, 4) enhanced metal availability in soil:root interface, and 5) active root foraging toward metal(loid) enriched soils. Among these mechanisms, understanding of the plant-root effect on metal(loid) dynamics and subsequent plant uptake is vital to overcome the inherit limitation of phytoremediation caused by low metal(loid) solubility in soils. Plant roots can influence the soil chemistry in the rhizosphere through changes in pH and exudation of organic compounds such as low-molecular-weight organic acids (LMWOAs) which consequently change metal(loid) solubility. The decrease in soil pH by plant release of $H^+$ results in increased metal solubility. Elevated levels of organic compounds in response to high metal soil concentrations by plant exudation may also increases metal concentration in soil solution through formation of organometallic complexes.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.4
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• pp.290-299
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• 2020

Purpose: Here, we verified that the actin cytoskeletal gene expression of human gingival fibroblasts was altered by the administration of trichloroacetic acid (TCA) and epidermal growth factor (EGF) using the nano-controlled releasing system. Materials and methods: The control and experimental groups were divided into 3 groups: the group with the TCA-only nano-controlled releasing system (EXP1), the group with the TCA- and EGF nano-controlled releasing system (EXP2), and the control group (CON) with 48-h incubation. Expression of 26 genes involved in the regulation of actin cytoskeleton were analyzed by real-time PCR followed by the determination of correlations and influential factors using the Pearson correlation analysis and multiple regression analysis. Results: Among 23 genes upregulated in EXP1 and EXP2, expression of 14 genes were significantly increased in EXP2 compared to EXP1. On the other hand, LPAR1 was downregulated only in EXP1, GNA13 was upregulated only in EXP2, and F2R was downregulated only in EXP2. Three Rac1-related genes and CDC42 were identified as the influential factors of the actin gene upregulation. Conclusion: The actin cytoskeleton genes in human gingival fibroblast were upregulated by the administration of TCA and EGF using HGC-based nano-controlled releasing system.

• Tuberculosis and Respiratory Diseases
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• v.71 no.2
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• pp.88-96
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• 2011

Background: It is known that cigarette smoke (CS) causes cell death. Apoptotic cell death is involved in the pathogenesis of CS-related lung diseases. Some members of the protein kinase C (PKC) family have roles in cigarette smoke extract (CSE)-induced apoptosis. This study was conducted to investigate the role of PKC epsilon in CSE-induced apoptosis in human lung fibroblast cell line, MRC-5. Methods: Lactate dehydrogenase release was measured using a cytotoxicity detection kit. The MTT assay was used to measure cell viability. Western immunoblot, Hoechst 33342 staining and flow cytometry were used to demonstrate the effect of $PKC{\varepsilon}$. Caspase-3 and caspase-8 activities were determined using a colorimetric assay. To examine $PKC{\varepsilon}$ activation, Western blotting was performed using both fractions of membrane and cytosol. Results: We showed that CSE activated $PKC{\varepsilon}$ by demonstrating increased expression of $PKC{\varepsilon}$ in the plasma membrane fraction. Pre-treatment of $PKC{\varepsilon}$ peptide inhibitor attenuated CSE-induced apoptotic cell death, as demonstrated by the MTT assay (13.03% of control, 85.66% of CSE-treatment, and 53.73% of $PKC{\varepsilon}$ peptide inhibitor-pre-treatment, respectively), Hoechst 33342 staining, and flow cytometry (85.64% of CSE-treatment, 53.73% of $PKC{\varepsilon}$ peptide inhibitor-pre-treatment). Pre-treatment of $PKC{\varepsilon}$ peptide inhibitor reduced caspase-3 expression and attenuated caspase-3, caspase-8 activity compared with CSE treatment alone. Conclusion: $PKC{\varepsilon}$ seem to have pro-apoptotic function and exerts its function through the extrinsic apoptotic pathway in CSE-exposed MRC-5 cells. This study suggests that $PKC{\varepsilon}$ inhibition may be a therapeutic strategy in CS-related lung disease such as chronic obstructive pulmonary disease.

• Korean Chemical Engineering Research
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• v.46 no.3
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• pp.619-625
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• 2008

The effects of thermal cycling on residual stresses in both inorganic passivation/insulating layer that is deposited by plasma enhanced chemical vapor deposition (PECVD) and organic thin film that is used as a bonding adhesive are evaluated by 4 point bending method and wafer curvature method. $SiO_2/SiN_x$ and BCB (Benzocyclobutene) are used as inorganic and organic layers, respectively. A model about the effect of thermal cycling on residual stress and bond strength (Strain energy release rate), $G_c$, at the interface between inorganic thin film and organic adhesive is developed. In thermal cycling experiments conducted between $25^{\circ}C$ and either $350^{\circ}C$ or $400^{\circ}C$, $G_c$ at the interface between BCB and PECVD $ SiN_x $ decreases after the first cycle. This trend in $G_c$ agreed well with the prediction based on our model that the increase in residual tensile stress within the $SiN_x$ layer after thermal cycling leads to the decrease in $G_c$. This result is compared with that obtained for the interface between BCB and PECVD $SiO_2$, where the relaxation in residual compressive stress within the $SiO_2$ induces an increase in $G_c$. These opposite trends in $G_cs$ of the structures including either PECVD $ SiN_x $ or PECVD $SiO_2$ are caused by reactions in the hydrogen-bonded chemical structure of the PECVD layers, followed by desorption of water.

• The KIPS Transactions:PartD
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• v.9D no.2
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• pp.235-242
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• 2002

We propose an advanced transaction scheduling protocol for concurrency control of multilevel secure databases in wireless mobile network environment. Wireless communication is characterized by frequent spurious disconnections. So short-lived transaction must quickly access database without any delay by long-lived one. We adapted two-phase locking protocol, namely traditional syntax-oriented serializability notions, to multilevel secure databases in wireless mobile network environment. Altruistic locking, as an advanced protocol, has attempted to reduce delay effect associated with lock release moment by use of the idea of donation. An improved form of a1truism has also been deployed for extended a1truistic locking. This is in a way that scope of data to he early released is enlarged to include even data initially not intended to be donated. Our protocol is based on extended altruistic locking, but a new method, namely bi-directional donation locking for multilevel secure databases (MLBiDL), is additionally used in order to satisfy security requirements and concurrency. We showed the Simulation experiments that MLBiDL outperforms the other locking protocols in terms of the degree of throughput and average waiting time.