• Korean Journal of Pharmacognosy
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• v.50 no.3
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• pp.205-218
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• 2019

This study was conducted to investigate the toxicity symptoms and approximate lethal dose (ALD) of Oplopanax elatus (Nakai) Nakai hydrothermal extract powder by single oral dose toxicity and 4 weeks of repeated oral dose determination. The Sprague-Dawley (SD) male and female rats were treated with 1,250 (low- dosage group), 2,500 (medium- dosage group) and 5,000 (high- dosage group) mg/kg. In the single oral dose toxicity test, no dead animals and toxic symptoms were observed during the experiment. And there were no related with anomalies in normal weight changes and autopsy results. In the four-week repeated oral dose determination test, no death animals and toxicity symptoms were observed during the experiment, and there were no abnormal results in weight changes, feed and negative intake measurements. Results of eye examination, urinalysis, hematological values and serum biochemical values, gross findings and absolute organ were not of singularity. These result demonstrated that no toxic symptoms were observed by the test substance Oplopanax elatus (Nakai) Nakai hydrothermal extract powder under this test condition, and the non-toxic content is determined to be 5,000 mg/kg/day.

• Korean Journal of Veterinary Research
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• v.44 no.1
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• pp.29-40
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• 2004

Because cleaning products are part of our everyday lives, it is essential that they should not present significant risks to health. However, many petrochemicals in most soaps and detergents can be absorbed through the scalp and skin and, over time, accumulate in the organs and tissues. This accumulation may result in brain, nerve, and liver damage. Therefore, it is interested in developing non-harmful detergent. According to Korea Research Institute of Chemical Technology, GC-100X may be non-harmful and non-corrosive alkaline ionic water (pH 12). It is composed of hydroxyl radicals and supplemented with xylitol. To evaluate influence of GC-100X on rats and beagles, GC-100X was diluted with distilled water (25%, 50%, and 100% solution respectively). Each of diluted GC-100X was daily treated per oral. In body weight analysis, urinary analysis, ophthalmological test and autopsy, we did not find any significance, but in serum biochemical analysis and hematological analysis, we found some significances in middle dose group compared with control group. These significances in serum biochemical analysis and hematological analysis may be not induced by GC-100X, because it was not found to be significant from control group in histopathological examination. Thus, it is concluded that NOEL(No Observed Effect Level) of GC-100X may be higher than all treatment doses used in this study, and GC-100X may be a non-toxic detergent.

• Journal of Korean Society of Forest Science
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• v.105 no.4
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• pp.505-509
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• 2016

This study was conducted to examine the effectiveness of various dressing materials applied to tree wounds in Korea. Significantly higher wound closure rates than those of controls were found when thiophanatemethyl paste (Topsin Paste$^{(R)}$) was applied to Ginkgo biloba, Zelkova serrata, and Prunus yedoensis; lanolin to Z. serrata and P. yedoensis; and tebuconazole paste (Silvacur$^{(R)}$) to P. yedoensis. However, significantly lower wound closure rates than those of controls were found when petroleum jelly (Vaseline$^{(R)}$) was applied to G. biloba, Z. serrata, and P. yedoensis. It was noted that the wounds of Z. serrata and P. yedoensis treated with petroleum jelly expanded due to the death of cambium located at the edge of the wounds. Wound closure rates applied with adhesive - non-toxic to human body (Okong bond$^{(R)}$) were also significantly lower than those of controls in Z. serrata. Pinus densiflora showed no reaction to any experimental wound dressing because of resin secreted from the exposed cambium.

• Korean Journal of Pharmacognosy
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• v.41 no.2
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• pp.136-140
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• 2010

This study was carried out to utilize non-toxic solvents instead of harmful solvents for the TLC(Thin Layer Chromatography) identification test of herbal medicines. It is recommended not to use harmful solvent such as chloroform at a viewpoint of clean analysis. In this study, we revised the identification test of 10 items in the Korea Pharmacopoeia(KP) and the Korean Herbal Pharmacopoeia(KHP) such as Cornus officinalis S. containing the harmful solvents on the developing solvent and established identification test that is utilized non-toxic solvents by HPTLC(High Performance Thin Layer Chromatography).

• Biomolecules & Therapeutics
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• v.5 no.2
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• pp.133-149
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• 1997

4-week repeated dose toxicity of DA-5018, a new capsaicin analogue analgesic agent, was examined in 5D rats at dosage levels of 0,0.4,2, 10 and 50 mg/kg/day. DA-5018 was administered orally to 17 males and 17 females per group at doses of 0, 10 and 50 mg/kg and to 12 males and 12 females per group at doses of 0.4 and 2 mg/kg. After the administration period, 5 males and 5 females at the 0, 10 and 50 mg/kg were placed on withdrawal for 2 weeks. Treatment-related clinical signs were observed at 10 and 50 mg/kg. Clinical signs observed immediately after the administration of DA-5018 were grooming, sedation or depression, lacrimation, atacia, reddening of extremities and ears, ventral or lateral recumvincy, respiratory distress, cyanosis and convulsion. Delayed-type clinical signs including focal scabbing and depilation around nose were also observed 1 or 2 weeks after the start of administration of DA-5018. Only at the 50 mg/kg group, corneal opacities, reduced body weight gain (male) and death (male 6/17, female 3/17) were noted. In blood biochemical analysis, serum levels of glucose and triglyceride decreased at 10 and 50 mg/kg. In hematological examination, there were increases in the number of red blood cell, hemoglobin content and percent of hematocrit at 10 and 50 mg/kg. Pulmonary enlargement and hemorrhagic spot, focal scabbing and depilation around nose and corneal opacities were seen at the necropsy of the animals died during the dosing of DA-5018 50 mg/kg. Focal scabbing and depilation around nose were observed in the animals terminally necropsied at doses of 10 and 50 mg/kg. Histopathological examination revealed pulmonary hemorrhage, focal necrosis in the scabbed area, corneal necrosis, fibrosis and neovasculization in the stroma. At 0.4 and 2 mg/kg, there were no significant toxic changes attributable to the administration of DA-5018. In conclusion, target organs following to 4-week repeated dose of DA-5018 in the rat were determined to be lung, skin and eyes. Definite toxic dose and no-observed-adverse-effect-level (NOAEL) were estimated to be 50 and 2 mg/kg/day, respectively.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.35.1-35.1
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• 2011

New photovoltaic (PV) materials and manufacturing approaches are needed for meeting the demand for lower-cost solar cells. The prototypal thin-film photovoltaic absorbers (CdTe and $Cu(In,Ga)Se_2$) can achieve solar conversion efficiencies of up to 20% and are now commercially available, but the presence of toxic (Cd,Se) and expensive elemental components (In, Te) is a real issue as the demand for photovoltaics rapidly increases. To overcome these limitations, there has been substantial interest in developing viable alternative materials, such as $Cu_2ZnSnS_4$ (CZTS) is an emerging solar absorber that is structurally similar to CIGS, but contains only earth abundant, non-toxic elements and has a near optimal direct band gap energy of 1.4~1.6 ev and a large absorption coefficient of ${\sim}10^4\;cm^{-1}$. The CZTS absorber layers are grown and investigated by various fabrication methods, such as thermal evaporation, e-beam evaporation with a post sulfurization, sputtering, non-vacuum sol-gel, pulsed laser, spray-pyrolysis method and electrodeposition technique. In the present work, we report an alternative method for large area deposition of CZTS thin films that is potentially high throughput and inexpensive when used to produce monolithically integrated solar panel modules. Specifically, we have developed an aqueous chemical approach based on chemical bath deposition (CBD) with a subsequent sulfurization heat treatment. Samples produced by our method were analyzed by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, absorbance and photoluminescence. The results show that this inexpensive and relatively benign process produces thin films of CZTS exhibiting uniform composition, kesterite crystal structure, and good optical properties. A preliminary solar cell device was fabricated to demonstrate rectifying and photovoltaic behavior.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.99.1-99.1
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• 2012

The thin-film photovoltaic absorbers (CdTe and $Cu(In,Ga)Se_2$) can achieve solar conversion efficiencies of up to 20% and are now commercially available, but the presence of toxic (Cd,Se) and expensive elemental components (In, Te) is a real issue as the demand for photovoltaics rapidly increases. To overcome these limitations, there has been substantial interest in developing viable alternative materials, such as $Cu_2ZnSnS_4$ (CZTS) is an emerging solar absorber that is structurally similar to CIGS, but contains only earth abundant, non-toxic elements and has a near optimal direct band gap energy of 1.4 - 1.6 eV and a large absorption coefficient of ~104 $cm^{-1}$. The CZTS absorber layers are grown and investigated by various fabrication methods, such as thermal evaporation, e-beam evaporation with a post sulfurization, sputtering, non-vacuum sol-gel, pulsed laser, spray-pyrolysis method and electrodeposition technique. In the present work, we report an alternative aqueous chemical approach based on chemical bath deposition (CBD) method for large area deposition of CZTS thin films. Samples produced by our method were analyzed by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, absorbance and photoluminescence. The results show that this inexpensive and relatively benign process produces thin films of CZTS exhibiting uniform composition, kesterite crystal structure, and some factors like triethanolamine, ammonia, temperature which strongly affect on the morphology of CZTS film.

• Korean Journal of Medicinal Crop Science
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• v.25 no.3
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• pp.152-159
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• 2017

Background: In this study, examined the effects of an extract of a mixture of Angelica gigas, Cnidium officinale, Paeonia lactiflora, and Rehmannia glutinosa fermented by Leuconostoc mesenteroides, with enhanced value and functionality. In oriental medicine, a mixture of these herbs is called Samultang. Methods and Results: In this study, we evaluated the effects of a fermented extract of Samultang on oxidative stress, procollagen type I expression, and melanin production. Samultang was extracted with 70% ethanol, followed by inoculation with Leuconostoc mesenteroides to obtain the fermented extract. The evaluation of viability of B16F10 cells and human foreskin fibroblast (HHF) revealed that both ethanol and fermented extracts of Samultang were non-toxic. The results of 1,1-diphenyl-2-picrylhydrazyl (DPPH) test showed that the fermented extract of Samultang ($SC_{50}value=100{\mu}g/m{\ell}$) was a more effective DPPH free radical scavenger than its ethanol extract. In addition, procollagen type I expression was higher in cells treated with the fermented extract of Samultang than in cells treated with ethanol. In the non-toxic concentration range, the fermented extract of Samultang showed strong inhibitory effect on melanin production in ${\alpha}-melanocyte$ stimulatin hormone-stimulated B16F10 cells ($IC_{50}=37.9{\mu}g/m{\ell}$). Conclusions: These results suggest that the fermented extract of Samultang has considerable protential as a cosmetic ingredient owing to its antioxidant, anti-wrinkle, and whitening effects.

• Corrosion Science and Technology
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• v.8 no.2
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• pp.89-92
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• 2009

Pure Ti as well as Ti-6Al-4V alloy exhibit excellent properties for dental implant applications. However, for a better biocompatibility it seems important to avoid in the composition the presence of V due to the toxic effects of V ion release. Thus Al and V free and composed of non-toxic element such as Nb, Zr alloys as biomaterials have been developed. Especially, Zr contains to same family in periodic table as Ti. The addition of Zr to Ti alloy has an excellent mechanical properties, good corrosion resistance, and biocompatibility. In this study, the electrochemical characteristics of Ti-Zr alloys for biomaterials have been investigated using by electrochemical methods. Methods: Ti-Zr(10, 20, 30 and 40 wt%) alloys were prepared by arc melting and homogenized for 24 hr at $1000^{\circ}C$ in argon atmosphere. Phase constitutions and microstructure of the specimens were characterized by XRD, OM and SEM. The corrosion properties of the specimens were examined through potentiodynamic test (potential range of -1500 ~ 2000 mV), potentiostatic test (const. potential of 300 mV) in artificial saliva solution by potentiostat (EG&G Co, PARSTAT 2273. USA).

• Biomolecules & Therapeutics
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• v.13 no.3
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• pp.143-149
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• 2005

We have demonstrated previously on a replication incompetent recombinant adenoviral vector, AdLPCD, in which the expression of cytosine deaminase (CD) gene is driven by the tumor-specific L-plastin promoter. The object of this study was to evaluate the efficacy of AdLPCD together with 5-fluorocytosine (5-FC) in suppression of the growth of established human tumor cells of ovary, Consistent with the knowledge that infection of OVCAR-3 cells with AdLPCD resulted in expression of a functional intracellular CD enzyme capable of converting 5-FC to 5-fluorouracil (5-FU) (Chung and Deisseroth, 2004), statistically significant differences in cytotoxicity were observed when AdLPCD infected cells were also exposed to 5-FC for 6 days (p=0.05), 9 days (p<0.0005) and 12 days (p<0.005), compared to 5-FC exposure alone, These results indicate that the CD gene delivered by adenoviral vector could efficiently sensitize OVCAR-3, otherwise non-toxic 5-FC. On the other hand, SKOV-3 cells, an ovarian carcinoma cell line, were more resistant to the CD/5-FC strategy compared with OVCAR-3 cells under the same condition. The results of present study suggest that the replacement of 5-FU with CD/5-FC in combination chemotherapy would be less toxic and much greater cytotoxicity than the conventional combination chemotherapy in some patients.