• Korean Journal of Food Science and Technology
• /
• v.19 no.3
• /
• pp.212-219
• /
• 1987

The rec-assay on Bacillus subtilis strains H17$({Rec}^+)$ and M45$({Rec}^-)$, the Ames test with modification of preincubation on Salmonella typhimurium TA98 and TA100 and DNA-breaking test on double strand calfthymus DNA were carried out using enzymatically browned substances obtained from the reaction of Prunus salicina (Red) enzyme and polyphenols. The spore rec-assay of enzymatic browning reaction products of pyrogallol, hydroxyhydroquinone. 3,4-dihydrohyoluene and chlorogenic acid showed non-mutagenic activity The spore rec-assay showed a little influence of ${Zn}^{2+}$ and ${Ni}^{2+}$ on the action of four kinds of enzymatic browning reaction products. The enzymatic browning reaction products of polyphenols did not show DNAbreaking activity. ${Cu}^{2+}$ of various metal ions influenced on DNA-breaking of enzymatic browning reaction products of pyrogallol. However, enzymatic browning reaction products of chlorogenic acid inhibited on DNA-breaking activity. Four kinds of enzymatic browning reaction products showed non-mutagenic activity on Salmonella typhimurium TA98 and TA100 with S-9 mix. In the mutagenicity on Salmonella typhimurium TA98 and TA100 with S-9 mix in the presence of benzo$({\alpha})$pyrene which is the carcinogenic substances, four kinds of enzymatic browning reaction products showed desmutagenic activity.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.10
• /
• pp.1588-1593
• /
• 2014

This study evaluated the genotoxic effects of 30 kGy of X-ray irradiation to four foods (chicken, egg powder, dried green onion, and black pepper). In bacterial reversion assay with Salmonella Typhimurium TA98, TA100, TA1535, and TA1537, the X-ray irradiated foods did not show a significantly increased number of revertant colonies in the presence or absence of the S9 metabolic activation system. In chromosomal aberration tests with Chinese hamster ovary (CHO) cells, the X-ray irradiated foods showed no increase in the frequency of chromosomal aberrations. In in vivo mouse micronucleus assay, the X-ray irradiated foods did not show any increase in the frequency of polychromatic erythrocytes with micronuclei. These results indicate that 30 kGy of X-ray irradiation to four foods (chicken, egg powder, dried green onion, and black pepper) showed no genotoxic effects under these experimental conditions.

• Journal of Animal Science and Technology
• /
• v.51 no.6
• /
• pp.503-510
• /
• 2009

This study investigated the effects of tannic acid (TA) in the diets for weanling pigs prepared with/without supplemental Fe on performance, hematology, fecal microflora and diarrhea incidence. Limestone and calcium phosphate used in Experiment 1 and 2 were of semi-synthetic and feed-grade quality, respectively; while the trace-mineral premix used in both the experiments was prepared without any added Fe source. In Experiment 1, 108 weaned pigs (Landrace ${\times}$ Yorkshire ${\times}$ Duroc, initially 6.46 ${\pm}$ 1.04 kg BW) were allotted to 3 treatments including control (diet added with $FeSO_4$ and antibiotic), T1 (diet devoid of $FeSO_4$ and antibiotic) and T2 (T1 diet added with 125 mg/kg TA). Each treatment had 4 replicates with 9 pigs in each pen. Feeding of T1 diet had a negative effect on the performance and plasma Fe status of pigs, while addition of TA to T1 diet resulted in performance of pigs comparable to pigs fed the control diet, reduced diarrhea incidence but had a negative influence on the hematological and plasma Fe indices. Additionally, pigs fed T2 diet had fewer (p<0.05) total anaerobic bacteria, Clostridium spp. and coliforms than pigs fed T1 diet, and greater number of Bifidobacterium spp. and Lactobacillus spp. in feces when compared with pigs fed control and T1 diets. In Experiment 2, 144 weaned pigs (Landrace ${\times}$ Yorkshire ${\times}$ Duroc, initially 6.00 ${\pm}$ 1.07 kg BW) were allotted to 4 dietary treatments including control (diet added with $FeSO_4$ and antibiotic) and diets devoid of supplemental Fe added with antibiotic (An), TA and both (AnTA). Each treatment had 4 replicates with 9 pigs in each pen. Addition of An, TA or both to diets devoid of supplemental Fe did not have any effect on performance, blood hematology and plasma Fe but resulted in reduced (p<0.05) diarrhea incidence and lower (p<0.05) fecal coliform population than pigs fed the control diet. These results suggest that TA has a negative influence on blood hematology and plasma Fe status when diets are inadequate in Fe; however, TA reduced diarrhea incidence and might have antimicrobial activity.

• Journal of the Korean Ceramic Society
• /
• v.46 no.6
• /
• pp.583-586
• /
• 2009

The Tantalum nitride has attracted wide at attention as issues related to the toxicity of Cd-related materials. But in the titration process of Ta$Cl_5$ solution with $NH_4$OH, $NH_4$Cl, as a by product, was remained in the prepared Tantalum precursor. The tantalum precursor with $NH_4$Cl was nitrided by ammonolysis. The red color tone of $Ta_3N_5$ was reduced by the residual $NH_4$Cl reduce. Therefore, amorphous Tantalum precursor was prepared by filtering process with as hydrous ethanol to remove the $NH_4$Cl. In the case of using Tantalum precursor without $NH_4$Cl, we successfully synthesized the Tantalum nitride with good red color. The value of red color tone was improved from $a^*$=36.8 to $a^*$=53.0. The synthesized powder was characterized by XRD, SEM, the Nitrogen / Oxygen Determinator, TG-DTA, and the CIE $L^*a^*b^*$ colorimeter.

• Korean Journal of Materials Research
• /
• v.4 no.5
• /
• pp.550-555
• /
• 1994

The effects of RTA treatment on the leakage current have been studied for tantalum pentoxide( $Ta_2O_5$) films deposited by PECVD on P-type(100) Si substrate using $TaCl_5$(99.99%) and $N_2O$(99.99%) gaseous mixture. The refractive index increased with increasing the deposition temperature and the maximum deposition rate was obtained at $500^{\circ}C$. The Ta-0 bond peak intensity of as-deposited $Ta_2O_5$ increased with increasing the deposition temperature through FT-IR analysis and the leakage current value was decreased with increasing the deposition temperature. The small leakage current value obtained after RTA treatment of as-deposited $Ta_2O_5$ was found to be due to the reduction of 0-deficient structure in the film. The increases of the oxygen coacentration and the Ta-0 bond peak intensity in the film after RTA treatment were measured by AES and FT-IR analyses.

• Environmental Analysis Health and Toxicology
• /
• v.15 no.4
• /
• pp.157-163
• /
• 2000

2- [(4- Cyanophenyl)amino] -3-chloro-1, 4- naphthalenedione (NQ-Y15) was asssayed for its genotoxic potential by using Salmonella typhimurium reversion assay and in vitro chromosome aberration test on Chinese hamster lung cells. In the Ames test, NQ-Y15 induced his + revertants of Salmonella typhimurium TA 98 and TA1537, reaching levels twice the negative control values. But, NQ-Y15 induced only his+ revertants of Salmonella typhimurium TA1537 more than twice the control values under the condition with metabolic activation system. In the cytogenetic test on chinese hamster lung cells. NQ -Y15 showed significant chromosomal aberrations, but the incidence was significantly reduced in the presence of metabolic activation.

• Preventive Nutrition and Food Science
• /
• v.1 no.2
• /
• pp.151-158
• /
• 1996

Antimutagenic effect of Doenjang (Korean soy paste) on various carcinogens in Salmonella typhimurium strains of TA98 and TA100 were studied. By the addition of methanol extract of Doenjang to aflatoxin B₁(AFB₁)in the experimental system, the mutagenicity of AFB₁ on the strains of TA98 and TA100 was com-pletely inhibited. The methenol extract of the Doenjang also inhibited the mutagencities induced by direct mutagens such as N-methy1-N'-nitro-N-nitroguanidine(MNNG)and 4-nitroquinoline-1-oxide(4-NQO), and another indirect mutagens of benzo(a) pyrene(BaP) and dimethylnitrosamine(DMN). From the solvents and thin layer chromatographic(TLC) fractionations, free fatty acid(s), especially linoleic acid in Doenjang seemed to be one of the active antimutagenic compounds.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2009.06a
• /
• pp.167-168
• /
• 2009

Phase pure barium magnesium tantalate $Ba(Mg_{1/3}Ta_{2/3})O_3$(BMT) nanopowders were synthesized at temperature as low as $220^{\circ}C$ through glycothermal reaction by using $Ba(OH)_2{\cdot}8H_2O$, $Mg(NO_3){\cdot}6H_2O$, and $TaCl_5$ as precursors and 1,4-butandiol as solvent. XRD, SEM, and TGA data support that glycothermal processing method provides a simple low temperature route for producing fine grained BMT nanopowders without alkaline mineralizers. BMT nanopowders synthesized at $220^{\circ}C$ showed more homogenous with rounded morphologies.

• Korean Journal of Materials Research
• /
• v.18 no.4
• /
• pp.181-186
• /
• 2008

In this study, tantalum (Ta) compacts were fabricated in a spark plasma sintering (SPS) process and their microstructure and mechanical properties were investigated. Ta compacts with a density of 99% were successfully fabricated by controlling the sintering conditions of the current and the temperature. The density and hardness were increased as the sintering temperature increased. The $Ta_2C$ compound was observed at the surface of the compacts due to the contact between the Ta powder and graphite mold during the sintering process. The main fracture mode showed a mixed type with intergranular and transgranular modes having some roughness.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11a
• /
• pp.97-100
• /
• 2001

This paper presents the characteristics of Ta-N thin-film strain gauges as high-temperature strain gauges, which were deposited on Si substrate by DC reactive magnetron sputtering in an argon-nitrogen atmosphere(Ar-(4∼16 %)N$_2$). These films were annealed for 1 hour in 2x10$\^$-6/ Torr vaccum furnace range 500∼1000$^{\circ}C$. The optimized conditions of Ta-N thin-film strain gauges were annealing condition(900$^{\circ}C$, 1 hr.) in 8% N$_2$ gas flow ratio deposition atmosphere. Under optimum conditions, the Ta-N thin-films for strain gauges is obtained a high resistivity, $\rho$=768.93 ${\mu}$Ω cm, a low temperature coefficient of resistance, TCR=-84 ppm/$^{\circ}C$ and a high temporal stability with a good longitudinal gauge factor, GF=4.12.