• Applied Chemistry for Engineering
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• v.35 no.4
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• pp.284-295
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• 2024

Chemical agents are classified according to their mechanism of toxicity into categories such as nerve agents, choking agents, blood agents, blister agents, etc. Among them, nerve agents cause toxic symptoms by binding with acetylcholinesterase (AChE) in the body, which breaks down neurotransmitters, thus disrupting the autonomic nervous system. In severe cases, this can lead to death, making it a critical chemical agent. Therefore, once it has penetrated into the human body, it is important to detoxify it swiftly. Antidotes used for detoxification include chemical medicines such as pretreatment agents, post-treatment agents, anticonvulsants, and bioscavengers. This review will address the uses, forms, components, and principles of detoxification of nerve agent antidotes and the association with bioscavengers.

• Korean Journal of Environmental Agriculture
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• v.29 no.2
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• pp.115-119
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• 2010

Zinc (Zn) is an essential element required for growth and development of plants. However, Zn can be toxic to plants when it presents excessive amount. Phytoextraction is an economic and environment-friendly technique using plants to clean-up metal-contaminated soils. However, the technique cannot be applied in highly metal-contaminated areas because plants will not normally grow in such conditions. Therefore, this research focuses on identifying chelating agents which are biodegradable and applicable to highly metalcontaminated areas. Zn as a target metal and cysteine (Cys), histidine (His), malate, citrate oxalate, succinate, and ethylenediamine (EDA) as biodegradable chelating agents were selected. Plants were grown on agar media containing various chelating agents with Zn to analyze the effect on plant growth. Malate and His slightly increased the inhibitory effect of Zn on root growth of plants, whereas Cys, citrate, oxalate, and succinate did not show significant effects. However, EDA strongly diminished the inhibitory effect of Zn on root growth. The effect of EDA is correlated with decreased Zn uptake into the plants. In conclusion, as biodegradable chelating agents, EDA is a good candidate for growth of plants in highly Zn-contaminated areas.

• YAKHAK HOEJI
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• v.51 no.1
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• pp.35-43
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• 2007

To investigate the immunomodulatory roles of cyclic AMP (CAMP) on macrophage- and T lymphocyte-mediated immune responses, CAMP elevating agents were employed and carefully re-examined under the activation conditions of the cells. Various inhibitors tested dose-dependently blocked tumor necrosis factor (TNF)-${\alpha}$ production with IC$_{50}$ values ranged from 0.04 to 300 ${\mu}$M. Of the inhibitors, cAMP-elevating agents showed lower cytotoxicity assessed by lactate dehydrogenase (LDH) release, suggesting less toxic and more selective. In particular co-treatment of dbcAMP with a protein kinase C inhibitor staurosporine displayed the synergistic inhibition of TNF-${\alpha}$ production. The modulatory effect of dbcAMP on TNF-${\alpha}$ and nitric oxide (NO) was significantly affected by treatment time of dbcAMP. Thus, post-treatment of dbcAMP (three hours before LPS) abrogated dbcAMP's inhibitory activity and rather enhanced TNF-${\alpha}$ level up to 60%. In contrast, additional NO production was shown at the co-treatment of dbcAMP with LPS. Unlike simultaneous treatment of phorbol 12-myristate 13-acetate (PMA) and interferon (IFN)-${\gamma}$co-treatment, the combination of dbcAMP with other NO-inducing stimuli did not show drastic overproduction of NO. cAMP elevating agents also diminished splenocyte proliferation stimulated by concanavalin (Con) A, phytohemaglutinin A (PHA) and lipopolysaccharide (LPS). In addition, dbcAMP but not rolipram strongly suppressed CD8$^+$ T cells (CTLL-2). Finally, cAMP elevating agents were differentially involved in regulating CD98-mediated cell-cell adhesion. Thus, dbcAMP and rolipram significantly enhanced the cell-cell adhesion, whereas forskolin blocked. Therefore, our results suggest that CAMP elevating agents participate in various immune responses mediated by macrophages and T cells with a different fashion depending on cellular environments and activation signals.

• Safety and Health at Work
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• v.3 no.4
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• pp.257-267
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• 2012

Occupational neurotoxic diseases have become increasingly common in Taiwan due to industrialization. Over the past 40 years, Taiwan has transformed from an agricultural society to an industrial society. The most common neurotoxic diseases also changed from organophosphate poisoning to heavy metal intoxication, and then to organic solvent and semiconductor agent poisoning. The nervous system is particularly vulnerable to toxic agents because of its high metabolic rate. Neurological manifestations may be transient or permanent, and may range from cognitive dysfunction, cerebellar ataxia, Parkinsonism, sensorimotor neuropathy and autonomic dysfunction to neuromuscular junction disorders. This study attempts to provide a review of the major outbreaks of occupational neurotoxins from 1968 to 2012. A total of 16 occupational neurotoxins, including organophosphates, toxic gases, heavy metals, organic solvents, and other toxic chemicals, were reviewed. Peer-reviewed articles related to the electrophysiology, neuroimaging, treatment and long-term follow up of these neurotoxic diseases were also obtained. The heavy metals involved consisted of lead, manganese, organic tin, mercury, arsenic, and thallium. The organic solvents included n-hexane, toluene, mixed solvents and carbon disulfide. Toxic gases such as carbon monoxide, and hydrogen sulfide were also included, along with toxic chemicals including polychlorinated biphenyls, tetramethylammonium hydroxide, organophosphates, and dimethylamine borane. In addition we attempted to correlate these events to the timeline of industrial development in Taiwan. By researching this topic, the hope is that it may help other developing countries to improve industrial hygiene and promote occupational safety and health care during the process of industrialization.

• Journal of the Korea Institute of Military Science and Technology
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• v.4 no.1
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• pp.188-197
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• 2001

Organophosphorus acid anhydrolases(OPAA) catalyzing the hydrolysis of toxic organophosphates have been found in a variety of prokaryotic and eukaryotic organisms. Of the several kinds of OPAA that can degrade nerve agents, such as DFP, sarin and soman, a OPAA gene harbored in the chromosomal DNA of Alteromonas haloplanktis strain was subcloned in order to develope an enzymatic degradation method of toxic organophosphorus compounds. For this 1481 bp DNA fragment containing OPAA gene and its flanking regions has been synthesized through PCR using chromosomal DNA of A. haloplanktis strain. After subcloning and subsequent expression, crude OPA anhydrolase was prepared and assayed. It was shown that the OPAA had a very high hydrolytic activity on DFP. The specific activity of the enzyme was 1,110 $\mu$mole.$min^{p-1}.mg^{-1}$ protein. It seemed that OPAA with such a high hydrolytic activity may give a good prospects to its use, as a biodegradation tool, in detoxifying toxic organophosphorus compounds, such as pesticides and chemical stockpiles which are posing a potential threat to the field environment and human health.

• Journal of Environmental Health Sciences
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• v.39 no.6
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• pp.483-491
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• 2013

Objectives: Electronic cigarettes are battery powered devices that convert a nicotine-containing liquid into an inhalable vapor. The device aerosolizes nicotine so that it is readily entrained into the respiratory tract, from where it enters the bloodstream. Information on the safety of E-cigarettes is required. Methods: Seventeen articles on studies analyzing toxic substances in the liquid and gas phases of electronic cigarettes were reviewed. Results: Tobacco-specific nitrosamines, bis(2-ethylhexyl) phthalate, formaldehyde and acetaldehyde, known to be carcinogenic agents in humans or animals, were detected in the liquid and gas phases. In addition, diethyl phthalate, acetone, ethanol, cresol, xylene, propylene, styrene, triethylene glycol, tetraethylene glycol, pentaethylene glycol cis-3-hexen-1-ol, methyl cinnamate and undecane were identified in the liquid and gas phases of E-cigarettes. Propylene glycol, glycerin, 1-methoxy-2-propanol, 1-hydroxy-2- propanone, acetic acid, 1-menthone, 2,3-butanediol, menthol, carvone, maple lactone, benzyl alcohol, 2-methyl-2-pentanoic acid, ethyl mantel, ethyl cinnamate, myosamine, benzoic acid, 2,3-bipyridine, cotinine, hexadecanoic acid, and 1'1-oxybis-2-propanol were detected in the vapors of E-cigarettes. Conclusion: The hazardous compounds identified in the liquid and gas phases of E-cigarettes should be controlled for the lowest concentrations in the raw materials and production procedures.

• Textile Coloration and Finishing
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• v.31 no.1
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• pp.33-41
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• 2019

In this report, nano-sized catalysts were introduced onto fabric surface to eliminate toxic chemicals assisted by physical adsorption. For chemical removal of toxic compounds, a series of zirconium-containing catalysts were synthesized and treated on fabric to catalyze the hydrolysis and oxidation of target molecules. Antimicrobial was also introduced for the research purpose to prove the compatibility of as-synthesized catalysts with other solutions. Zirconium ligated with hydroxyl group and MOF(Metal-Organic Frameworks) were exploited as catalyst for removal of toxic compounds, while zinc complex was used for an antimicrobial to culminate in a chemical shield. Once fabrics were functionalized, fabrics were washed 2 or 5 times for a washing durability test. The amount of catalyst in textile were measured by ICP-MS and weight increasing ratio of fabrics.

• Journal of the Korean Chemical Society
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• v.52 no.3
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• pp.257-265
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• 2008

The synthesis, characterization and bioevaluation of five new tetrahydroquinazolines was reported. Initially cyclohexanones were prepared and they were used as synthons to get the target molecules. These were condensed with substituted benzaldehydes and the resulting chalcones were treated with guanidine hydrochloride . All the molecules were non-toxic to human cells and showed significant antibacterial activity.

• Molecular & Cellular Toxicology
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• v.2 no.3
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• pp.216-221
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• 2006

The cholinesterase-inhibiting organophosphorous (OP) compounds known as nerve agents are highly toxic. The principal toxic mechanism of OP compounds is the inhibition of acethylcholine esterase (AChE) by phosphorylation of its catalytic site. The reversible competitive inhibition of AChE may prevent the subsequent OP intoxication. In this study, three-dimensional quantitative structure-activity relationship (3D-QSAR) was performed to investigate the relationship between the 29 compounds with structural diversity and their bioactivities against AChE. In particular, predictive models were constructed using the comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). The results indicate reasonable model for CoMFA ($q^{2}=0.453,\;r^{2}=0.697$) and CoMSIA ($q^{2}=0.518,\;r^{2}=0.696$). The presence of steric and hydophobic group at naphtyl moiety of the model may lead to the design of improved competitive inhibitors for organophosphorous intoxication.

• The Korea Journal of Herbology
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• v.20 no.3
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• pp.67-74
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• 2005

Objectives : This study was carried out to determine if Scutellariae Radix have protective effect against cell injury induced by various toxic agents in rat kidney slices. Methods : Water(SWe) and methanol(SMe) extracts were prepared for this experiment. Cell injury was estimated by measuring lactate dehydrogenase(LDH). Lipid peroxidation was examined by measuring malondialdehyde. Results : SMe prevented the LDH release by CCl4, menadione, tert-butyl hydroperoxide and mercury treatment in vitro in kidney slices, but SWe prevented the LDH release by CCl4 and mercury. SMe also prevented reduction in GSH by CCl4 and lipid peroxidation induced by mercury. Conclusions : Thus, SMe may have more powerful efficacy on anti-oxidative effects when compared with SWe. And further studies have to be followed concerned with procedure of extraction of SMe and its change of effects.