• Journal of Environmental Science International
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• v.14 no.5
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• pp.513-520
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• 2005

For the destruction of toxic chlorinated organic compounds, this study proposes improved supercritical water oxidation method (multistep oxidation) using sodium nitrate as an oxidizer. This method solves the problems involved in the existing supercritical water oxidation method. Multistep oxidation means that $NaNO_3$ is oxidized to $N_2\;via\;NaNO_2$ and NO. Toxic and hard to destroy organic substances like para-dichlorobenzen(4-DCBz), polychlorinate biphenyl(PCB) ware oxidized to non toxic substances in a condition, in which rapid pressure and temperature rise is restrained as much as possible. 4-dichlorobenzene(4-DCBz) and Polychlorinate biphenyl(PCB) in condition$(450^{\circ}C,\;p_w=0.25g/cm^3,\;30min)$ Was discomposed perfectly.

• Molecular & Cellular Toxicology
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• v.5 no.2
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• pp.153-159
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• 2009

In this study, we assessed the acute and subacute toxicity of Angelica gigas Nakai (A. gigas Nakai) extracts, which are comprised of decursin and decursinol angelate (D/DA) in rats. For the oral acute toxicity test, Sprague-Dawley (SD) male and female rats were gavaged with two doses of D/DA (200 and 2,000 mg/kg body weight) and then observed for any toxic symptoms for 2 weeks. The LD$_{50}$ value for the rats was greater than 2,000 mg/kg body weight for both male and female rats, which indicates that there were no toxic symptoms induced by doses of up to 2,000 mg/kg body weight. For the subacute toxicity study, rats were treated with D/DA at doses of 2 and 20 mg/kg body weight once a day for 30 days. There were no significant changes in body weight and food intake observed during the subacute toxicity study. In addition, no differences were observed between the control and treated groups when urinalysis was conducted or when hematology and biochemical parameters were evaluated. Finally, histopathological examination of the organs did not reveal any lesions in the control or treated groups. Taken together, these findings indicate that D/DA is safe and non-toxic.

• Journal of Korean Ophthalmic Optics Society
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• v.1 no.2
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• pp.13-18
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• 1996

In this study, contact lens care solutions were compared to each other for cytotoxic effect on cultured mouse fibroblasts by the use of neutral red(NR) assay. This study tested the cytotoxicity of 12 cleaning solutions, 2 lubricants and 5 multipurpose solutions(MPS) at 1%, 2%, 3% and 5% concentrations. These solutions are manufactured in Korea and foreign countries. The relative cytotoxic comparison of these solutions showed that some of them are toxic, three of the cleaning solutions were especially highly toxic 10 cells, so most fibroblasts were dead at 1% concentration. The toxic cleaning solutions have more components than other solutions. But both lubricants and MPSs are non-cytotoxic 10 cells. Some of these solutions did not have any descriptions or indications. They are very dangerous to eyes. From this study, contact lens care solutions should be tested for cytotoxic effects.

• Advances in nano research
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• v.3 no.4
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• pp.243-255
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• 2015

In this investigation, ecotoxicity of nano and micro metal oxides, namely silica ($SiO_2$) and alumina ($Al_2O_3$), on the growth of green algae (Porphyridium aerugineum Geitler) is discussed. Effects of nano and micro particles on the growth, chlorophyll content and protein content of algae are analysed using standard protocols. Results indicate that $SiO_2$ nano and micro $SiO_2$ particles are non-toxic to P. aerugineum Geitler up to a concentration of 1000 mg/L. In addition, $Al_2O_3$ microparticles are less toxic to P. aerugineum Geitler, whereas $Al_2O_3$ nanoparticles are found to be highly toxic at 1000 mg/L. Moreover, $Al_2O_3$ nanoparticles decrease the growth, chlorophyll content, and protein content of tested algae. In addition, zeta potential and contact angle are also important in enhancing the toxicity of metal oxide nanoparticles in aquatic environment. This study highlights a new insight into toxicity evaluation of nanoparticles on beneficial aquatic organisms such as algae.

• Journal of Food Hygiene and Safety
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• v.9 no.3
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• pp.111-116
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• 1994

The acute toxicity of orally administered Yan-Sheng health liquid (YSHL), water extracts from twelve Chinese drugs (Cervi Cornu, Lonicerae Flos, Foeniculi Fructus, Glycyrrhizae Radix, Liriopis Tuber, Raphani Semen, Bombyx, Ginseng Radix alba, Cinnamomi loureirii Cortex, Epimedii Herba, Zingiberis Rhizoma, Lycii Fructus) was evaluated in male and female Sprague-Dawley rats and ICR mice. Rats and mice aging 5 weeks were gavaged with 0, 2.0, 3.0, 4.4, 6.7, 10.0, 66.7, or 100.0 ml/kg of YSHL. No animal died by oral treatment and no toxic symptom was observed in the treated animals during 5 days. The body weight of the treated animals was not significantly different from the controls. The results of macroscopic examination on the organs of the treated animals revealed no abnormal findings. Therefore, it was concluded that YSHL was practically non-toxic when it was orally administered to rats and mice, and its LD50 was suspected to be greater than 100 ml/kg in rats and mice.

• Journal of applied mathematics & informatics
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• v.27 no.1_2
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• pp.385-400
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• 2009

The adverse effect of harmful plankton on the marine ecosystem is a topic of deep concern. To investigate the role of such phytoplankton, a mathematical model containing distinct dynamical equations for toxic and non-toxic phytoplankton is analyzed. Stability analysis of the resulting three equation model is carried out. A continuous time variation in toxin liberation process is incorporated into the model and a stability analysis of the resulting delay model is performed. The distributed delay model is then extended to include the spatial distribution of plankton and the delay-diffusion model is analyzed with spatial and spatiotemporal kernels. Conditions for diffusion-driven instability in both the cases are derived and compared to explore the significance of these kernels. Numerical studies are performed to justify analytical findings.

• Membrane and Water Treatment
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• v.4 no.2
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• pp.95-108
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• 2013

Metal ions exist in seawater, groundwater and industrial wastewaters. These source waters can be recycled if their concentrations are reduced. A number of processes can be applied for this purpose. Liquid-liquid extraction is one of the promising methods. In this paper, experimental results are presented on the removal of Cr(VI) using Aliquat-336, a reactive carrier, in sunflower oil (a non-toxic solvent). The performance of this new system is compared with those of kerosene (a toxic solvent). The extent of removal of Cr(VI) from samples with high and low concentrations are presented. The process was upgraded to a bench-scale module that can selectively remove about 50-90% Cr(VI) from samples of groundwater. Thus this process can produce water within the acceptable range for recycling and for use in secondary purposes such as irrigation.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.52-53
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• 2001

In order for vitamin D to be active, it needs to get metabolized to 1, 25 (OH)$_2$D3. This active metabolite of vitamin D induces epithelial cell differentiation and is antiproliferative. However, at the efficacious concentration, the natural ligand for VDR is hypercalcemic and toxic to cells. Therefore, numerous analogs have been synthesized with the hope of generating a compound that retains vitamin D activity and is non-toxic.(omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10b
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• pp.9-10
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• 2001

In order for vitamin D to be active, it needs to get metabolized to 1, 25 (OH)$_2$D3. This active metabolite of vitamin D induces epithelial cell differentiation and is antiproliferative. However, at the efficacious concentration, the natural ligand for VDR is hypercalcemic and toxic to cells. Therefore, numerous analogs have been synthesized with the hope of generating a compound that retains vitamin D activity and is non-toxic.(omitted)

• Bulletin of the Korean Chemical Society
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• v.30 no.4
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• pp.825-828
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• 2009

Alum $(KAl(SO_4)_2{\cdot}12H_2O)$ is an inexpensive, efficient, non‐toxic and mild catalyst for the synthesis of bis(indolyl)methanes by the reaction of 1H-indole with various aldehydes/ketones under the influence of ultrasound irradiation in solvent‐free condition. The remarkable advantages of this method are the simple experimental procedures, shorter reaction times, high yields of product and green aspects by avoiding toxic catalysts and solvents.