• BMB Reports
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• v.31 no.2
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• pp.183-188
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• 1998

2-chloroethylethyl sulfide (CEES) is an alkylating agent that readily reacts with a wide variety of biological molecules causing metabolic abnormality. The mechanism of cell death during CEES injury is poorly understood. We have examined the effect of exposure of thymocytes with various concentrations of CEES to determine the pattern of cell death in thymocytes injury induced by CEES. In the present study, we show that two patterns of cell death occurred by either one of two mechanisms: apoptosis and necrosis. Exposure to low level of CEES (100 ${\mu}M$) for 5 h caused an induction of apoptosis on thymocytes, as identified by the following criteria: DNA fragmentation visualized by the characteristic "ladder" pattern was observed upon agarose gel electrophoresis and morphological features were revealed by microscopical observations. In contrast, exposure to high levels of CEES (500 ${\mu}M$) induce necrotic features such as cell lysis. Thus, depending on the concentrations, CEES can result in either apoptotic or necrotic cell damage. Our findings suggest that thymocytes which are not killed directly, but merely injured by low levels of CEES, are able to activate an internally-programmed cell death mechanism, whereas thymocytes receiving severe damages apparently can not.

• Toxicological Research
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• v.13 no.1_2
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• pp.61-69
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• 1997

Exposure of splenocytes to 2-chloroethylethyl sulfide (CEES) resulted in the cell death, and the cytotoxicity of CEES was prevented by inhibitors of lysosomal hydrolases. Therefore, it has been postulated that the cytotoxicity of CEES may be partially due to the lysosomal labilization. This study, based on this mechanism, was undertaken to determine whether aminoglycoside antibiotics as inhibitors of lysosomal phospholipases and their combinations with other lysosome stabilizers can be useful as a treatment to reduce the CEES toxicity in mice. 2-Chloroethylethyl sulfide (20 mg/kg body weight) was injected ip into female ICR mice, and candidate compounds were administered ip before or after the CEES challenge. Kanamycin (40 mg/kg body weight) as effective as deferoxamine (100 mg/kg body weight) enhanced the survival rate after 5 days of intoxication from 10% of control to 50 - 60%. The most effective was found to be the combination of kanamycin, cycloheximide, deferoxamine and dextrose showing an almost full protection against 2LD50 of CEES. Consistent with the protection of the CEES toxicity, the decrease of body weight in mice intoxicated with CEES was effectively prevented by kanamycin or its combinations. It is suggested that kanamycin or its combination (kanamycin, cycloheximide, deferoxamine and dextrose) would be one of effective antidotes against the CEES poisoning in mice.

• BMB Reports
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• v.28 no.1
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• pp.79-82
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• 1995

Exposure of spleen lymphocytes to 2-chloroethylethyl sulfide (CEES) leads to a reduction of the intracellular ATP level, followed by a decrease in cell viability. Addition of nicotinamide, an inhibitor of poly(ADP-ribose) polymerase (PADPRP), restores both ATP level and viability, indicating that an activation of PADPRP is responsible for the cytotoxicity of CEES. The involvement of a $Ca^{2+}$-mediated process in cytotoxicity is suggested. Verapamil, EGTA, trifluoperazine, and butacaine exhibit a partial protection (20 to 58%) against the cytotoxicity of CEES. Investigation of the causative role of proteolytic degradation in cell death indicate that pepstatin and leupeptin exert a substantial protective effect (60 to 70%), suggesting the involvement of lysosomal destabilization in CEES-induced cytotoxicity. Also, lysosomotropic agents markedly decrease the cytotoxicity. Lysosomal labilization may be a mechanism for the cytotoxicity of CEES.

• Journal of Microbiology and Biotechnology
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• v.25 no.11
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• pp.1842-1848
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• 2015

Cyanidin-3-glucoside (C3G) has been known to be more bioavailable than cyanidin-3-rutinoside (C3R), the most abundant anthocyanin in black raspberry (Rubus occidentalis). The aim of this study was to enhance the bioavailability of anthocyanins in black raspberry by cleaving ʟ-rhamnose in C3R using crude enzyme extracts (CEEs) from Aspergillus usamii KCTC 6956, A. awamori KCTC 60380, A. niger KCCM 11724, A. oryzae KCCM 12698, and A. kawachii KCCM 32819. The enzyme activities of the CEEs were determined by a spectrophotometric method using ρ-nitrophenyl-rhamnopyranoside and ρ-nitrophenyl-glucopyranoside. The CEE from A. usamii had the highest α-ʟ-rhamnosidase activity with 2.73 U/ml at 60℃, followed by those from A. awamori and A. niger. When bioconversion of C3R to C3G in black raspberry was analyzed by HPLC-DAD, the CEEs from A. usamii and A. awamori hydrolyzed 95.7% and 95.6% of C3R to C3G, respectively, after 2 h incubation. The CEEs from A. kawachii and A. oryzae did not convert C3R to C3G in black raspberry.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.1
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• pp.107-124
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• 2023

As getting in 4th Industrial Revolution Times, Continuing Education Enrolled Students(CEES) trying to find loophole for jepordized current life and need job transfer have surged their interest significantly on starting new business to bring up their post career after retirement through self-improvement. Government and university have actively initiated diverse policies of promoting startup for CEES in kicking off entrepreneurship courses and programs. However, relevant main policy, 'The 2nd University Startup Education Five-Year Plan (draft)' have too chiefly focused on theoretical start-up education rather than practical courses, causing the problem of inappropriate support for implementing real startup and business (Ministry of Education, 2018). This study is brought to empirically investigate the effect of self-efficacy as perspective of the impact of entrepreneurship education on entrepreneurial intention and behavior to come up with problem of poor entrepreneurial environment and entrepreneurship education to CEES. As to empirical research, this paper deliver on-line survey to CEES from September to October 2022, collect 207 effective feedbacks, In order to verify the reliability of the scale, the Cronbach's Alpha Coefficient (Cronbach's α) was calculated, analyzed, and measured. For hypothesis test, this paper utilize the multiple regression analysis statistical analysis method and use the SPSS 22.0 statistical processing program. Empirical results show, first, it was found that self-efficacy had a significant effect on start-up education. Second, start-up education had a significant effect on the intention to start a business of adult learners. Third, start-up education had a significant effect on the start-up behavior of adult learners. Fourth, self-efficacy had a significant effect on the intention of adult learners to start a business. Fifth, self-efficacy had a significant effect on the start-up behavior of adult learners. Sixth, self-efficacy had a mediating effect in the relationship between entrepreneurship education and adult learners' intention to start a business. Seventh, self-efficacy had a complete mediating effect in the relationship between start-up education and adult learners' start-up behavior. This paper is brought three significant implications. First, main consideration developing entrepreneurship education tools for CEES need to falls on defining potential needs of CEES as segmenting as to coming up with diversity of CEES's characteristics such as gender, age, experience, education, and occupation. Second, as to design specific entrepreneurship education program, both practical training program of utilizing CEES's career field experience benchmarking best practice startup and venture cases from domestic and global, and professional startup program of CEES initiating directly startup from ideation to develop business plan with pitching and discussing. Third, entrepreneurship education for CEES should be designed to incubate self-efficacy to enhance entrepreneurial intention of implementing entrepreneurial behavior as a real, eventually leading solid support system of self-improvement for CEES' Retirement life planning.

• Journal of Sensor Science and Technology
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• v.28 no.3
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• pp.139-145
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• 2019

Precautionary detection of chemical warfare agents (CWAs) has been an important global issue mainly owing to their toxicity. To achieve proper detection, many studies have been conducted to develop sensitive gas sensors for CWAs. In particular, metal-oxide semi-conductors (MOS) have been investigated as promising sensing materials owing to their abundance in nature and excellent sensitivity. In this review, we mainly focus on various MOS-based gas sensors that have been fabricated for the detection of two specific CWA simulants, 2-chloroethyl ethyl sulfide (2-CEES) and dimethyl methyl phosphonate (DMMP), which are simulants of sulfur mustard and sarin, respectively. In the case of 2-CEES, we mainly discuss $CdSnO_3-$ and ZnO-based sensors and their reaction mechanisms. In addition, a method to improve the selectivity of ZnO-based sensors is mentioned. Various sensors and their sensing mechanisms have been introduced for the detection of DMMP. As the reaction with DMMP may directly affect the sensing properties of MOS, this paper includes previous studies on its poisoning effect. Finally, promising sensing materials for both gases are proposed.

• Journal of the Korea Institute of Military Science and Technology
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• v.26 no.5
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• pp.422-430
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• 2023

To build an automated system detecting toxic chemicals from Raman spectra, we have to obtain sufficient data of toxic chemicals. However, it usually costs high to gather Raman spectra of toxic chemicals in diverse situations. Tackling this problem, we develop methods to generate synthetic Raman spectra of DMMP and 2-CEES without actual experiments. First, we propose certain mathematical transforms to augment few original Raman spectra. Then, we train deep generative models to generate more realistic and diverse data. Analyzing synthetic Raman spectra of toxic chemicals generated by our methods through visualization, we qualitatively verify that the data are sufficiently similar to original data and diverse. For conclusion, we obtain a synthetic dataset of DMMP and 2-CEES with the proposed algorithm.

• Journal of the Korean Chemical Society
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• v.58 no.1
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• pp.100-104
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• 2014

Magnetite nanoparticles were prepared by co-precipitation method and then silica was coated onto the surface of $Fe_3O_4$ by hydrolysis of TEOS. The silica coated magnetite nanoparticles were characterized for its structural, microstructural, optical, vibrational and magnetic properties by X-ray diffraction analysis, Scanning electron microscopy, UV-visible spectroscopy, Infrared spectroscopy and Vibration sample magnetometer, respectively. XRD study confirmed the presence of $SiO_2$ on the surface of magnetite nanoparticles. SEM study indicated that with increase in TEOS content the particles become bigger and mono-disperse. It was also found that the silica coating prevents magnetic particles from aggregation and imparts excellent stability.

• Membrane Journal
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• v.24 no.2
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• pp.167-175
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• 2014

For selectively permeable membrane based on cellulose acetate butyrate (CAB) and polyethyleneimine (PEI) with water vapor transportability and DMMP protective performance, we intended to improve protective performance of the membrane against CEES using several additives. Results showed that CAB/PEI membranes possessed performance with good water vapor permeation (${\geq}1,800g/m^2/day$) and enhanced protective capability against CEES contamination ($7.1{\sim}11.5{\mu}g/cm^2{\cdot}day$). Of these membranes, the membrane containing $Ag^+$ ion and ionic exchange resin showed the best protective performance. And, we identified that the CAB/PEI membranes show excellent protection against aerosols with various particle sizes ($0.005{\sim}3{\mu}m$) simulating biological agents.

• Journal of Microbiology and Biotechnology
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• v.19 no.7
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• pp.698-708
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• 2009

High rate sulfate reduction under acidic conditions opens possibilities for new process flow sheets that allow the selective recovery of metals from mining and metallurgical waste and process water. However, knowledge about high-rate sulfate reduction under acidic conditions is limited. This paper investigates sulfate reduction in a membrane bioreactor at a controlled pH of 5. Sulfate and formate were dosed using a pH-auxostat system while formate was converted into hydrogen, which was used for sulfate reduction. Sulfide was removed from the gas phase to prevent sulfide inhibition. This study shows a high-rate sulfate-reducing bioreactor system for the frrst time at pH 5, with a volumetric activity of 188 mmol $SO_4^{2-}$/I/d and a specific activity of 81 mmol $SO_4^{2-}$volatile suspended solids/d. The microbial community at the end of the reactor run consisted of a diverse mixed population including sulfate-reducing bacteria.