• Food Science of Animal Resources
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• v.39 no.1
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• pp.84-92
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• 2019

Listeria monocytogenes is a major cause of serious foodborne illness in the dairy foods. Although Caenorhabditis elegans model is well established as a virulence model of pathogenic bacteria, its application on L. monocytogenes is critically unclear. The objective of this study was to carry out an evaluation of L. monocytogenes toxicity using C. elegans nematode as a simple host model. We found that C. elegans nematodes have high susceptibility to L. monocytogenes infection, as a consequence of accumulation of bacteria in the worms' intestine. However, L. innocua, which is known to be non-toxic, is not accumulate in the intestine of worms and is not toxic similarly to Escherichia coli OP50 known as the normal feed source of C. elegans. Importantly, immune-associated genes of C. elegans were intensely upregulated more than 3.0-fold when they exposed to L. monocytogenes. In conclusion, we established that C. elegans is an effective model for studying the toxicity of L. monocytogenes and we anticipate that this system will result in the discovery of many potential anti-listeria agents for dairy foods.

• Journal of The Korean Society of Clinical Toxicology
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• v.18 no.2
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• pp.94-101
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• 2020

Purpose: This study examined the clinical and epidemiological characteristics of intensive care unit (ICU) patients admitted or died in the emergency medical center with acute-poisoning to investigate the variables related to the prognosis. Methods: The data were collected from poisoning patients admitted or died in the emergency medical center of a general hospital located in Seoul, from January 2014 to February 2020. The subjects of this study were 190 patients. The medical records were screened retrospectively, and the clinical and epidemiological characteristics of the patients in the emergency room (ER) and ICU were examined to investigate the contributing factors that influence the poor prognosis. Results: The study analyzed 182 patients who survived after being admitted to the intensive care unit (ICU). The results are as follows. The mental change (87.4%) was the most common symptom. Sedative poisoning (49.5%) was the commonest cause. For most patients, pneumonia (26.9%) was the most common complication. Hypotension (23.7%), tachycardia (42.1%), fever (15.8%), seizures (10.5%), dyspnea (2.6%), high poisoning severity score (PSS), type of toxic material, mechanical ventilator application (39.5%), inotropes application (39.5%), and pneumonia (55.3%) were correlated the LOS over 5 days in the ICU. 8 patients died. In the case of death pesticides and carbon monoxide were the main toxic materials; tachycardia, bradycardia, and hypotension were the main symptoms, and a mechanical ventilator and inotropes were applied. Conclusion: Patients with unstable vital signs, high PSS, and non-pharmaceutical poisoning had a prolonged LOS in the ICU and a poor prognosis.

• Environmental Mutagens and Carcinogens
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• v.23 no.2
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• pp.56-62
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• 2003

The liver progenitor cells could form a potential target cell population fore both tumor-initiating and -promoting chemicals. Induction of drug-metabolizing and antioxidant enzymes, including AhR-dependent CYP1A1, NQO-1 and AKR1C9, was detected in the rat liver epithelial WB-F344 "stem-like" cells. Additionally, WB-F344 cells express a functional, wild-type form of p53 protein, a biomarker of genotoxic events, and connexin 43, a basic structural unit of gap junctions forming an important type of intercellular communication. In this cellular model, two complementary assays have been established for detection of the modes of action associated with tumor promotion: inhibition of gap junctional intercellular communication (GJIC) and proliferative activity in confluent cells. We found that the PAHs and PCBs, which are AhR agonists, released WB-F344 cells from contact inhibition, increasing both DNA synthesis and cell numbers. Genotoxic effects of some PAHs that lead to apoptosis and cell cycle delay might interfere with the proliferative activity of PAHs. Contrary to that, the nongenotoxic low-molecular-weight PAHs and non-dioxin-like PCB congeners, abundant in the environment, did not significantly affect cell cycle and cell proliferation; however both groups of compounds inhibited GJIC in WB-F344 cells. The release from contact inhibiton by a mechanism that possibly involves the AhR activation, inhibition of GJIC and genotoxic events induced by environmental contaminants are three important modes of action that could play an important role in carcinogenic effects of toxic compounds. The relative potencies to inhibit GJIC, to induce AhR-mediated activity, and to release cells from contact inhibition were determined for a large series of PAHs and PCBs and their metabolites. In vitro bioassays based on detection of events on cellular level (deregulation of GJIC and/or proliferation) or determination of receptor-mediated activities in both ?$stem-like^{\circ}{\times}$ and hepatocyte-like liver cellular models are valuable tools for detection of modes of action of polyaromatic hydrocarbons. They may serve, together with concentration data, as a first step in their risk assessment.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.263-264
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• 2002

The tribological characteristic of several environmentally friendly lubricating base stocks was examined, and the effect of some commonly used additives on th tribological behavior of the lubricating oils was comparatively investigated on a four-ball machine. It has been found that the commercial additives including butene sulfide, wax chloride, zinc dialkyldithiophosphate and ashless P-N type agent helped to improve the friction-reducing and antiwear properties as well as the extreme pressure behavior. Non-toxic nanoscale $(CF)_x$ showed the best friction-reducing ability, though it registered relatively poor extreme pressure properties. The mechanism on friction of nano-scale material is discussed.

• Toxicological Research
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• v.13 no.1_2
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• pp.149-152
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• 1997

This test was performed to evaluate the ocular and skin irritation of EPO (Erythropoietin). The results as follows: 1. Ocular irritation test There were no observed clinical signs, body weght changes by EPO during experimental period. The acute ocular irritation index(A.O.I.), mean ocular irritation index(M.O.I.) and Day-7 individual ocular irritation index(I.O.I.) of EPO at dose of 1000U and 10, 000U were 0, respectively. Therefore we evaluated that EPO was non-toxic to eyes. 2. Skin irritation test There were no observed clinical signs, body weght changes and gross pathologic findings by EPO during experimental period. There were no observed erythema, eschar formation and edema formation on intact and abraded skin treated by EPO. The primary irritation index(P.I.I.) of EPO at dose of 1000U and 10, 000U were 0, respectively and were evaluated none irritating product about skin irritation.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.5
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• pp.574-580
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• 2013

Green technology encompasses a growing group of methods and materials, from techniques for generating energy and alternative resources to non-toxic cleaning products. Green technology is expected to solve current problems in atmospheric environment such as climate changes due to green house gases and hazardous air pollutants. This paper provides a review on the status of green technology and policy guidelines in Korea as well as the green technology for air pollutants. It presents the R&D projects and future direction in atmospheric environment, and the green technology in mobile source air pollution. Emerging green technology contributes to sustainable growth and development of atmospheric environmental industry for better air quality.

• Journal of the Korean Society of Safety
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• v.32 no.1
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• pp.47-52
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• 2017

Chemical accidents occur by a variety of causes and aspects. Accident preparedness substances (APS) are defined by toxic chemicals highly likely to cause accidents due to their high acute toxicity, explosiveness or likely to cause severe damage where a chemical accident occurs among the chemicals. APS is designated and announced by Presidential Decree. However, chemical accidents occurred for recent 7 years were arisen mainly from non-accident preparedness substances, and only 24 species were included as chemical accident trigger among total 69 APS. In addition, APS were designated in 2014 and the list has not been updated since then although it needs to be amended in several aspects. Accordingly, this study analyzes the necessity of modification of APS management, and presents improved plans.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.305.2-305.2
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• 2016

Tin monosulfide (SnS) is one promising candidate absorber material which replace the current technology based on cadmium telluride (CdTe) and copper indium gallium sulfide selenide (CIGS) for its suitable optical band gap, high absorption coefficient, earth-abundant, non-toxic and cost-effective. During past years work, thin film solar cells based on SnS films had been improved to 4.36% certified efficiency. In this study, Tin monosul fide was obtained by atomic layer deposition (ALD) using the reaction of Tetrakis (dimethylamino) tin (TDMASn, [(CH3)2N]4Sn) and hydrogen sulfide (H2S) at low temperatures (100 to 200 oC). The direct optical band gap and strong optical absorption of SnS films were observed throughout the Ultraviolet visible spectroscopy (UV VIS), and the properties of SnS films were analyzed by sanning Electron Microscope (SEM) and X-Ray Diffraction (XRD).

• YAKHAK HOEJI
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• v.38 no.1
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• pp.46-56
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• 1994

Daily oral administration to Sprague Dawly rats for 4 weeks of DWP-301, at doses of 0, 500, 1000, 2000 mg/kg presented following results; 1) No animals died and there were no significant differences in general signs, body weight, food consumption, urinalysis haematological, biochemical, gross pathological and histopathological examination between control and treated rats. 2) Water consumption, pH-, protein- urobilinogen-, ketone-values in urine were significantly increased in the treated male and female rats. It is supposed that these differences in animals are a consistent feature of repeated overdosage with test suspensions. The results indicate that the non toxic dose of test compounds in rats is over 2000 mg/kg in this test system.

• YAKHAK HOEJI
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• v.39 no.4
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• pp.450-460
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• 1995

The acute toxicity of fthalide in rat was studied in vivo by the observations of the changes in hematogram, serological parameters, content of cytochrome p-450, activities of NADPH-cytochrom c reductase, glucose-6-phosphatase, and the contents of cholinesterase and carboxylesterase in liver. Fthabde is a practically non-toxic substance(LD50 is 3.86g/kg), but rats were intoxicated with fthabde at a oral dose of 100 mg/kg for 12 days. WBC were significantly decreased and activities of ALT and LDH, on the cotrary, the content of glucose in serum were slightly increased. Cytochrome p-450 and lipid peroxide in liver were significantly increased in the fthalide-intoxicated rats. The longer administration of fthalide showed further increase of carboxylesterase activity in liver and serum, but decrease of activities of glucose-6-phosphatase and cholinesterase in liver and serum. These results show that fthatide can induce the hepatocellular injury and neurotoxicity.