• Journal of agriculture & life science
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• v.51 no.1
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• pp.35-43
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• 2017

This research was carried out to excessive water tolerance test among corn accessions collected from India to breed corn cultivars targeting India market. The corn accessions were 20 Inbred lines and cultivars from India as well as Korean cultivars Gwangpyungok and Chaloksusu. Excessive water tolerance test was done in the green house by immerging the pots containing corn seedlings for two weeks. Then, the plant heights were measured to compare the control plants that were not grown in the immerging state. The results showed that seven accessions of high tolerance in flooding; H2(92.9%), H18(88.8%), CN114A(98.1%), CN351A(94.3%), Super900M(95.3%), P3394(98.8%), 31N27(96.7%) in which the percent is comparison to the control plants. Whereas nine accessions showed high damage by immerging; H1(78.9%), H8(73.4%), H10(77.1%), H19(79.0%), H26(74.1%), H31(75.7%), H34(77.5%), H36(77.4%), H40(74.6%). However, the reduction on the contents of chlorophyll a, chlorophyll b, carotenoids in leaf revealed contrast results to the flooding tolerance. Particularly, H36($7.249{\mu}g{\cdot}mg^{-1}$) and H40($7.642{\mu}g{\cdot}mg^{-1}$) showed rapid reduction in the chlorophyll a content during the flooding treatment. Whereas two Indian commercial varieties 37N27($0.630{\mu}g{\cdot}mg^{-1}$) and P3394($1.208{\mu}g{\cdot}mg^{-1}$) showed slight reduction. The reduction of chlorophyll a and carotenoid contents was positively correlated during the excessive water stress.

• Korean Journal of Materials Research
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• v.28 no.8
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• pp.435-439
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• 2018

MA Al alloys are examined to determine the effects of alloying of Mg and Cu and rolling on tensile deformation behavior at 748 K over a wide strain rate range($10^{-4}-10^3/s$). A powder metallurgy aluminum alloy produced from mechanically alloyed pure Al powder exhibits only a small elongation-to-failure(${\varepsilon}_f$ < ~50%) in high temperature(748 K) tensile deformation at high strain rates(${\acute{\varepsilon}}=1-10^2/s$). ${\varepsilon}_f$ in MA Al-0.5~4.0Mg alloys increases slightly with Mg content(${\varepsilon}_f={\sim}140%$ at 4 mass%). Combined addition of Mg and Cu(MA Al-1.5%Mg-4.0%Cu) is very effective for the occurrence of superplasticity(${\varepsilon}_f$ > 500%). Warm-rolling(at 393-492 K) tends to raise ${\varepsilon}_f$. Lowering the rolling-temperature is effective for increasing the ductility. The effect is rather weak in MA pure Al and MA Al-Mg alloys, but much larger in the MA Al-1.5%Mg-4.0%Cu alloy. Additions of Mg and Cu and warm-rolling of the alloy cause a remarkable reduction in the logarithm of the peak flow stress at low strain rates (${\acute{\varepsilon}}$< ~1/s) and sharpening of microstructure and smoothening of grain boundaries. Additions of Mg and Cu make the strain rate sensitivity(the m value) larger at high strain rates, and the warm-rolling may make the grain boundary sliding easier with less cavitation. Grain boundary facets are observed on the fracture surface when ${\varepsilon}_f$ is large, indicating the operation of grain boundary sliding to a large extent during superplastic deformation.

• Journal of Veterinary Clinics
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• v.10 no.2
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• pp.203-214
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• 1993

With the use of a rat surgical model, the ability of carboxymethylcellulose and ibuprofen in the reduction of abdominal adhesion was examined. Seventy seven female rats were randomly divided into 7 groups : (1) control, (2) 2% CMC, (3) 3% CMC, (4) ibuprofen 25mg, (5) ibuprofen 50mg, (6) combination of ibuprofen 25mg and 2% CMC and(7) combination of ibuprofen 50mg and 3%, CMC. Following induction of abrasion injuries on ileum, colon and both uterine horns with a surgical blads, the rats in groups (2), (6) were infused with 2% CMC solution singly or in combined Infection of 25 mg/kg of ibuprofen for three consecutive days, the rats In groups (3), (7) were infused with 3% CMC solution singly or In combined Injection of 50mg/kg of ibuprofen for three consecutive days. The rats in groups (4), (5) were injected only with 25 mg or 50 mg/kg of ibuprofen for three consecutive days. After 10 days the abdominal cavities were opened and the appearance of formed adhesion were graded. The changes of body weight, CBC and blood chemicals were also evaluated at 3, 6 and 10 days after operation. In ileum, the rats in the groups (2), (6) and (7) showed less adhesion formation. In colon, there were significant differences(p<0.05) in adhesion formation in all treated groups as compared to control. In both uterine horns, there were significant decrease(p<0.05) of adhesion formation in groups(2), (6) and (7) in comparison with other groups. The increasing rate of body weight was evident in group (3) and fibrinogen concentrations at 6 and 10 days revealed significant decrease (p<0.01) in group (7), whereas there was no consistent change in CBC and blood chemicals. Therefore, it can be sugested that the infusion of 2% CMC solution with or without the injection of 25 mg/kg of ibuprofen and 3% CMC solution with the injection of 50 mg/kg of ibuprofen are effective and safe following abdominal surgery,

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.55.2-55.2
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• 2012

Intensive theoretical and experimental studies have been carried out at Korean Institute of Science and Technology (KIST) on controlling the bio absorbing rate of the Mg alloys with high mechanical strength through tailoring of electrochemical potential. Key technology for retarding the corrosion of the Mg alloys is to equalize the corrosion potentials of the constituent phases in the alloys, which prevented the formation of Galvanic circuit between the constituent phases resulting in remarkable reduction of corrosion rate. By thermodynamic consideration, the possible phases of a given alloy system were identified and their work functions, which are related to their corrosion potentials, were calculated by the first principle calculation. The designed alloys, of which the constituent phases have similar work function, were fabricated by clean melting and extrusion system. The newly developed Mg alloys named as KISTUI-MG showed much lower corrosion rate as well as higher strength than previously developed Mg alloys. Biocompatibility and feasibility of the Mg alloys as orthopedic implant materials were evaluated by in vitro cell viability test, in vitro degradation test of mechanical strength during bio-corrosion, in vivo implantation and continuous observation of the implant during in vivo absorbing procedures. Moreover, the cells attached on the Mg alloys was observed using cryo-FIB (focused ion beam) system without the distortion of cell morphology and its organ through the removal of drying steps essential for the preparation of normal SEM/TEM samples. Our Mg alloys showed excellent biocompatibility satisfying the regulations required for biomedical application without evident hydrogen evolution when it implanted into the muscle, inter spine disk, as well as condyle bone of rat and well contact interface with bone tissue when it was implanted into rat condyle.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.198-198
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• 2016

An ideal orthopedic implant should provide an excellent bone-implant connection, less implant loosening and minimum adverse reactions. Commercial pure titanium (CP-Ti) and Ti alloys have been widely utilized for biomedical applications such as orthopedic and dental implants. However, being bioinert, the integration of such implant in bone was not in good condition to achieve improved osseointegraiton, there have been many efforts to modify the composition and topography of implant surface. These processes are generally classified as physical, chemical, and electrochemical methods. Plasma electrolytic oxidation (PEO) as an electrochemical route has been recently utilized to produce this kind of composite coatings. Mg ion plays a key role in bone metabolism, since it influences osteoblast and osteoclast activity. From previous studies, it has been found that Mg ions improve the bone formation on Ti alloys. PEO is a promising technology to produce porous and firmly adherent inorganic Mg containing $TiO_2$($Mg-TiO_2$ ) coatings on Ti surface, and the amount of Mg introduced into the coatings can be optimized by altering the electrolyte composition. In this study, a series of $Mg-TiO_2$ coatings are produced on Ti-6Al-4V ELI dental implant using PEO, with the substitution degree, respectively, at 0, 5, 10 and 20%. Based on the preliminary analysis of the coating structure, composition and morphology, a bone like apatite formation model is used to evaluate the in vitro biological responses at the bone-implant interface. The enhancement of the bone like apatite forming ability arises from $Mg-TiO_2$ surface, which has formed the reduction of the Mg ions. The promising results successfully demonstrate the immense potential of $Mg-TiO_2$ coatings in dental and biomaterials applications.

• Journal of the Korean Society of Tobacco Science
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• v.7 no.1
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• pp.7-13
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• 1985

Effect of the two PVY strains(PVY-VB and PVY-VN) on yield and chemical constituents of tobacco plants was determined in roar. NC2326 and Burley 21. The virus was inoculated 6 and 8 weeks after transplanting, respectively. The strains and time of inoculation were most critical factors for yield reduction. The greatest reduction was caused by the necrotic strain (PVY-VN) inoculated 6 weeks after transplanting, accounting for the loss of 40% in var. NC2326 and of 45% in var.. Burley21. When inoculated 8 weeks after transplanting with the necrotic strain, only 17% reduction was recorded in roar. Burley21, but no reduction occurred in roar. NC2326. Generally less reduction was caused by the PVY-VB strain, ranging 12-16% depending on the time of inoculation and/or variety. Compared to healthy tobacco, PVY infected tobacco contained higher concentrations of total nitrogen, protein nitrogen, nitrate nitrogen, and lower total sugar in cured leaf of roar. NC2326. Total alkaloid, P, Mg, Ca, and K levels were not altered. In var. Burley21, protein nitrogen and nitrate nitrogen increased, but other chemical components were not changed. Necrotic strain-infected tobacco with a severe symptom had higher nitrogen than did mild strain-infected tobacco.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.4
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• pp.359-362
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• 1996

A study was conducted to assess the influence of copper on the total sulphur amino acid requirements of broiler chickens reared under two growing periods. The TSAA levels used were 0.73, 0.83, 0.93% with copper levels of 0, 125, 250 and 375 mg/kg for the starter period and the TSAA levels of 0.72, 0.79 and 0.86% with copper levels of 0, 125, 250 and 375 mg/kg for the grower period. Total feed consumption, body weight gain and feed L gain ratio were used as the parameters for the assessment. The results showed that adding copper at 250 mg/kg to the diets improved feed : gain ratio of the starter broilers and resulted in small improvement of body weight gain and feed : gain ratio of the grower broilers. Growth was depressed in relation to the reduction of feed intake on the chicks fed diet containing 375 mg/kg copper. There was a significant interaction between dietary TSAA and copper levels for feed intake, hence, indicating that the supplementation of copper at the level of 375 mg/kg increased the TSAA requirement of the starter broilers, although no interference with the requirement of grower broilers.

• Biomolecules & Therapeutics
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• v.3 no.1
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• pp.38-46
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• 1995

DA-125, a new anthracycline antitumor antibiotic, was administered at dose levels of 0, 0.04, 0.2 and 1.0 mg/kg/day intravenously to pregnant and subsequently delivered Sprague-Dawley rats from day 17 of gestation to day 21 of lactation. Effects of test agent on general toxicity of dams and growth, behaviour and mating performance of F1 offspring were examined. At 1 mg/kg, one out of the twentytwo dams showed difficult delivery, characterized by a stillbirth. Reduction in body weight, loss in food intake, and decrease in spleen weight were also observed in dams. In addition, the lower rates of successful performances in memory test (28.6%) and necrosis of tail end (9.5%) were seen in F1 offspring. At 0.04 and 0.2 mg/kg, no toxic effect on dams and F1 offspring was observed. There were no malformed Fl and F2 fetuses in all groups. The results indicate that the no effect dose levels(NOELs) of DA-125 are 0.2 mg/kg/day for dams and Fl offspring, and over 1 mg/kg/day for F2 fetuses.

• The Korean Journal of Community Living Science
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• v.27 no.2
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• pp.233-243
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• 2016

This study examined the antioxidant activity and lipid composition of rats fed a high fat-high cholesterol diet containing Salvia plebeia water extract. Three levels (50 mg/kg, 200 mg/kg, 500 mg/kg) of Salvia plebeia water extract were administered to seven weeks old male Sprague Dawley rats for four weeks. The activity of glutathione peroxidase in serum was high in all groups that received the Salvia plebeia water extract (p<0.05). The glutathione reductase activity was high (p<0.05) in groups that received 50 mg/kg and 500 mg/kg of Salvia plebeia water extract. When rats received Salvia plebeia water extract, the content of MDA (malondialdehyde) in the serum and liver was low in all groups. In addition, the serum total lipid, triglyceride, total cholesterol and LDL-cholesterol contents decreased significantly (p<0.05). Total cholesterol and triglyceride levels in the liver were significantly lower in the group that received the Salvia plebeia water extract than in the control group (p<0.05). Salvia plebeia water extract improves lipid metabolism and it almost meets with the increase of antioxidant activity and peroxide formation reduction. Based on these results, supplemented of a high fat-hypercholesterol diet with Salvia plebeia can increase antioxidant activity and depress peroxide formation in serum, as well as liver cholesterol and triglycerides.

• Journal of Environmental Health Sciences
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• v.37 no.2
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• pp.133-140
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• 2011

Antimicrobial activity and bactericidal activity of Caesalpinia sappan L. extracts were investigated against five food-borne pathogens, E. coli, S. aureus, S. typhimurium, B. cereus and L. monocytogenes. Methanol extract of Caesalpinia sappan L. revealed antimicrobial activities against five pathogens. In particular, by paper disc diffusion the highest activity was shown against L. monocytogenes. Antimicrobial activities of methanol extracts showed the most potent activities, but hexane fraction had no activity. Fractions of ethyl acetate and butanol turned out to have higher antimicrobial activities against Gram(+) bacteria than Gram(-) bacteria. The minimum inhibitory concentration against five food-borne pathogens was 1.563 mg/ml on Gram(+) bacteria and 3.125 mg/ml on Gram(-) bacteria. The result of antimicrobial activity in a shaking flask method showed that bacterial growth rate fell by more than 99.999% at 3.125 mg/ml of methanol extract. The highest rate of viable reduction (99.998%) was shown at 0.781 mg/ml of methanol extract against L. monocytogenes. After five minutes of reaction between test strains and methanol extracts, the growth rates of five kinds of bacteria were reduced by more than 99.999% at a concentration of 100 mg/ml. Therefore, it is suggested that methanol extracts of Caesalpinia sappan L. can be developed as a natural sanitizer or disinfectant.