• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.559-568
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• 2020

Epidermal growth factor (EGF) is a hormone protein that affects cell growth and proliferation, and has various medical applications. In the present study, the gene of human EGF was codon-optimized with E. coli and the expression vector was constructed by cloning into pRSET. In order to obtain the recombinant human EGF in an active form rather than an inclusion body, chaperone co-expression was attempted along with codon optimization, for the first time. The expressed human EGF was isolated in the pure form by performing Ion Exchange Chromatography in two consecutive runs. ELISA analysis showed that the activity of purified EGF was greater than 99%, which is similar to commercially available EGF. Cell proliferation test confirmed that the recombinant human EGF has the ability to promote cell proliferation of human skin fibroblasts. The human EGF expression system of this study gives a significant amount of protein, and does not require the renaturation step and the additional chromatographic system to remove a fusion contaminant, thereby providing a very useful alternative to conventional expression systems for the preparation of recombinant human EGF.

• Korean Journal of Weed Science
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• v.4 no.2
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• pp.154-162
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• 1984

The persistence of butachlor and nitrofen in different soil conditions applied organic matter, lime, and other pesticides was studied under submerged and field moisture capacity. Degradation of the herbicides in soil was significantly retarded by autoclaving the soil and half-life of nitrofen was much longer than that of butachlor under this condition. Submerging the soil enhanced degradation of the herbicides, in particular that of nitrofen. On the other hand, half-life of nitrofen under field moisture capacity was twice longer than that of butachlor. Increased amendment of rice straw to the soil shortened the half-life of nitrofen under submerged soil, however it prolonged that of butachlor when the amendment was exceeded 1000kg/10a level. Liming the soil stimulated herbicide decomposition in the soil, which appears to be pH independent. Butachlor degradation in submerged soil was slightly stimulated by simultaneous application of fungicides and insecticides, but nitrofen persistence was not influenced.

• Applied Biological Chemistry
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• v.24 no.1
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• pp.1-6
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• 1981

Studios on the effects of rice straw amendments, soil autoclaving and repeated application related to disappearance of diazinon (diethyl 2-isopropyl -4-methyl -6-pyrimidinyl phosphorothionate) in submerged soils and paddy water were conducted under the laboratory conditions. Degradation of diazinon was slightly accelerated by the amendment of rice straw. The amended soil had 2.4 days shorter half life for diazinon than unamended soil. By autoclaving soils, diazinon degradation was greatly inhibited. The autoclaved soil had about 20 days longer half life for diazinon than the non-autoclaved soil. After repeated application of diazinon granules to the submerged soils, rapid degradation of the insecticide occured in flooded soils and paddy water. The development of diazinon degrading factors in flooded soils and paddy water after repeated application was roughly proportional to the increase of the frequency of diazinon application. By autoclaving soils and paddy water which received repeated application of diazinon, no rapid biodegradation of the insecticide occurred during the 30 days incubation period.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.4
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• pp.386-393
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• 1984

This study was carried out to identify the ecological characters easily changeable with the conditions of temperature and day-length and to ascertain the managable means which can optimize the barley plants to secure the maximae yield and early heading under controlled condition. Yield and yield components were greatly varied with temperature. Especially, effective tiller formation and grain filling of sub-tillers were more favorably affected by thermal treatment than those of main tiller. In thermic response, 'Kangbori' was less susceptible than others, while 'Sacheon #6' showed particular susceptability. The varietal differences of photoperiodic response were recognized on all investigated traits and their degree of response were similar to those with temperature. Among varieties, 'Kangbori' was comparably sensitive on several characters while 'Sacheon #6' displaying low light-sensitivity. The turning point at which heading might be radically stimulated was estimated as about 10.5 hour day-length in 3 tested varieties and above 18 hours of irradiance was considered ineffective for more rapid heading. The condition under which barley varieties may obtain maximal yield and resonably early heading was 15$^{\circ}C$ in temperature and 12 to 15 hours of day-length, regardless of varieties. of day-length, regardless of varieties.

• Korean Journal of Environmental Agriculture
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• v.26 no.4
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• pp.313-318
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• 2007

In greenhouse farming, a variety of humic acids have been applied to improve soil conditions and plant growth. However, it is still unclear that how humic acids combined with chemical fertilizers affect growth and quality of fruit vegetable crops. This study was conducted to determine the combination effect of humic acids and chemical fertilizers on the growth and fruit quality of tomato (Lycopersicon esculentum MILL.) grown under greenhouse conditions. Three different formulation types of humic acid were used: liquid type A, liquid type B and solid type C. The tomato plants were grown in three treatment combination plots and in conventional fertilizer (CF) plot with recommended levels of nitrogen, phosphorus and potassium: HA combined with CF (HA+CF), HB combined with CF (HB+CF) and HC combined with CF (HC+CF). For most of growth characteristics (i.e. leaf number, internode length, maximum leaf length, leaf width and chlorophyll contents) determined in this experiment, no significant differences were observed between all combination treatments and CF. However, integrated fruit qualities (i.e. averaged weight, sugar contents and acidity) were slightly improved in the humic acid combined with CF treatments when compared with CF alone treatment. No phytotoxicity was observed with humic acid treatments. However, further studies will probably be needed to use widely and safely these humic acids, in order to ensure a maximizing growth, fruit yield and quality of tomato.

• Journal of Food Hygiene and Safety
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• v.6 no.1
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• pp.27-40
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• 1991

;ABSTRACT-The effects of gastric ulcer induced by restraint and water-immersion stress on gastric carcinogenesis in Wistar male rats treated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) were examined. Rats of group 1 were 2iven stress for 8 hours before they were received MNNG (100 mg/l) in drinking water for 20 weeks. Rats of group 2 were received MNNG first for 2 weeks and then were given stress once a week from 3rd to 12th weeks, with simultaneous MNNG adminitration and followed by MNNG only until 20th weeks. Rats of group 3 were received MNNG only as a positive control and rats of group 4 were not treated with carcinogen. All groups were sacrificed in 20 weeks. Sections of the pyloric mucosa were stained by avidin-biotin peroxidase complex (ABC) immuno-histochemical method. PAPG (pepsinogen isozyme 1 altered pyloric gland), body weight change, gross lesions and histopathological changes were examined. The results obtained from these studies were summarized as follows: 1. The mean body weight gains of the rats fed with carcinogens (group 1, 2, 3) were significantly lower than that of group 4 (control group, without carcinogen. p<0.05). However, the differences of the mean body weight of rats treated with carcinogen were not significant. 2. Stress treatment (group 1 and 2) increased the appearance of the numbers of PAPG (Pepsinogen 1 Altered Pyloric Gland) induced by carcinogen significantly compared with that of group 3 (carcinogen only, p<0.01). 3. The incidence rate of mucosal hyperplasia in pylorus was significantly increased in group 2 compared with group 3 (p<0.05).0.05).

• Korean journal of applied entomology
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• v.9 no.1
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• pp.7-13
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• 1970

1. Kum Nam Poong which is highly susceptible to bacterial leaf blight was used as the host plant throughout this experiment. Xanthomonas oryzae 6526 was inoculated on the top of upper leaves by single needle inoculation method. After 14 days, the enlarged spots were examined in the experimental pots. Each of 3 levels of nitrogen, phosphate and potassium pots were arranged at random with three replications. 2. The amounts of nitrogen fertilizer applied and the lesion development of bacterial leaf blight were positively correlated regardless of application of phosphate and potassium fertilizers. 3. The effect of phosphate fertilizer on the lesion development was not significantly different from standard level. The lesion development was stimulated when the amount of phosphate fertilizer was increased as twice as standard level. 4. The inhibitory effect of potassium fertilizer on leaf blight was maximum by applying standard level. The stimulative effect of potassium fertilizer on the lesion development, however, was noticed. when potassium fertilizer applied was increased as twice as the standard level. 5. The heading date and spike number of rice plant were significantly correlated with the lesion development, and such phenomena were depended on the amount of nitrogen fertilizer applied regardless of the other fertilizers applied in this experiment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.2
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• pp.192-201
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• 1985

Two experiments, utilizing 204 broiler chicks of the Maniker strain, were conducted to study the effects of dried whey and chitin on the growth of chicks. In the first experiment, diets containing 5%, 10%, or 15% dried whey, or a control diet with no whey, were fed to chicks from 1 day to 4 weeks of age. There were no significant differences among the dietary groups, with respect to the rate of growth or protein or feed efficiency. In the second experiment, chicks were fed with diets containing no whey, 2% chitin, 20% dried whey, or 20% dried whey plus 2% chitin, from 1 day to 4 weeks of age. Adverse effects (diarrhea, crooked toes and enlarged cecum) were observed in the group fed 20% dried whey. The protein efficiency ratio (PER) and feed efficiency ratio (FER) tended to improve in the dietary groups with dried whey, as compared to the control group. No significant differences were observed in the total carcass nitrogen and lipid levels of dietary groups. But the chitin-supplemented diets tended to improve on the growth rate compared to the groups without chitin. The results of the two experiments suggest that the growing broiler chick can tolerate up to 15% dried whey in the diet, without any harmful effect on growth. Also, chitin may improve the poorer growth rate of chicks fed dried whey, but not all of the adverse effects of whey.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.463-469
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• 2016

In this paper, compressive strength and water permeability performance for two types of crack self-healing materials such as SH-PO-0 composed of mineral admixtures(expansive agent, swelling material and crystal growth agent) and SH-PO-(5, 15, 30) blended with SH-PO-0 and phosphate additive(PO) dissolving easily calcium ion, were evaluated. The test results show that the water flow of SH-PO-0 decreased steeply at the early age although compressive strength decreased about 9% at 28 days compared with OPC. The higher PO replacement ratio is, the lower compressive strength and more improved water permeability performance is, and thus, based on such results, adequate PO replacement ratio is 15%. It is also found that the self-healing performance of SH-PO-15 was quite improved at the early ages and however, the performance of SH-PO-15 is similar to one of SH-PO-0 at long-term ages, and 28 days compressive strength of SH-PO-15 decreased about 8% compared with SH-PO-0. In addition, it is confirmed from the analysis of SEM-EDS that calcium ions of SH-PO-15 were crystallized more than those of SH-PO-0.

• Journal of the Korea Institute of Building Construction
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• v.20 no.5
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• pp.391-397
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• 2020

This study is to compare and analyze the strength, drying shrinkage and carbonation properties of lightweight aggregate mortar using recycling water as prewetting water and mixing water. The flow, compressive strength, split tensile strength, drying shrinkage and carbonation depth of lightweight aggregate mortar with recycling water were measured. As test results, the mortar flow was similar in all mixes regardless of the recycling water content. The compresseive strength of the RW5 mix with 5% recycling water as prewetting water and mixing water was the highest value, about 53.9 MPa after 28 days. In addition, the tensile strength of lightweight mortar was about 3.4 to 3.8 MPa, indicating 7 to 9% of the compressive strength value regardless of recycling water content. In the case of drying shrinkage, the RW2.5 mix using 2.5% recycling water showed the lowest shrinkage rate as about 0.107% at 56 days. The drying shrinkage of the plain mix without recycling water was relatively higher than the RW2.5 and RW5 mix. The RW5 mix showed lowest carbonation depth compared to other mixes. In this study, the RW5 lightweight aggregate mortar with 5% recycling water exhibits excellent compressive strength and carbonation resistance. Therefore, it is considered that if the recycling water, a by-product of the concrete industry, is properly used as prewetting water and mixing water of lightweight mortar and concrete, it will be possible to increase the recycling rate of the by-product and contribute to improve the property of lightweitht aggregate mortar and concrete.