• Korean Journal of Soil Science and Fertilizer
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• v.34 no.1
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• pp.64-70
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• 2001

To verify the newly developed decision assisting expert system for nitrogen fertilizer application NES to Illinois cornfields, a couple of N rate studies from Dr. Howard and five Illinois Agricultural Experiment Stations were applied. Four types of recommendations including the current Illinois recommendation, Hoeft recommendation, NES, and maximum economic recommendation were compared with each other for the crop yields, profits, recovery rate, and N losses to cornfields. The N rate of NES recommendation, considering productivity index (PI), soil organic matter content (SOM), and pre-sidedressing nitrate concentration (PSNT) level, was the lowest in comparison to those of other recommendations. However, N recovery rate in NES was generally higher and the resulting N loss was lower than others. But, adherence to the recommendations may also reduce farmers income if environmental expense did not considered. Therefore, NES will be more effective by adding the factors including environmental expense, tillage systems, crop rotation, and other agricultural management parameters.

• Journal of Sensor Science and Technology
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• v.11 no.5
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• pp.309-318
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• 2002

A stoichiometric mixture of evaporating materials for $CdIn_2S_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $CdIn_2S_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $630^{\circ}C$ and $420^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of $CdIn_2S_4$ single crystal thin films measured with Hall effect by van der Pauw method are $9.01{\times}10^{16}\;cm^{-3}$ and $219\;cm^2/V{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the $CdIn_2S_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=2.7116\;eV-(7.74{\times}10^{-4}\;eV)T^2/(T+434)$. The crystal field and the spin-orbit splitting energies for the valence band of the $CdIn_2S_4$ have been estimated to be 0.1291 eV and 0.0248 eV, respectively, by means of the photocurrent spectra and the Hopfield quasi cubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}5$ states of the valence band of the $AgInS_2$/GaAs epilayer. The three photocurrent peaks observed at 10K areascribed to the $A_1$-, $B_1$-, and C1-exciton peaks for n = 1.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.23 no.6
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• pp.283-290
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• 2013

A stoichiometric mixture of evaporating materials for $MgGa_2Se_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $MgGa_2Se_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $610^{\circ}C$ and $400^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by double crystal X-ray diffraction (DCXD). The temperature dependence of the energy band gap of the $MgGa_2Se_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=2.34 eV-(8.81{\times}10^{-4}eV/K)T^2/(T+251K)$. The crystal field and the spin-orbit splitting energies for the valence band of the $MgGa_2Se_4$ have been estimated to be 190.6 meV and 118.8 meV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $MgGa_2Se_4$/GaAs epilayer. The three photocurrent peaks observed at 10 K are ascribed to the $A_{1^-}$, $B_{1^-}$exciton for n = 1 and $C_{27}-exciton$ peaks for n = 27.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.56-62
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• 2015

Various pretreatment methods were evaluated to prevent tissue softening of heated onion. Changes in onion tissue firmness during heating were explained by 3-mechanism model consisting of texture hardening at low temperature ($60-80^{\circ}C$) and substrate softening at high temperature. Preheating of onion in a $Ca^{2+}$-containing solution significantly improved its texture after high-temperature heating. The improvement of firmness by preheating at low temperature was related to the formation of strong cross-linking between carboxyl groups and $Ca^{2+}$ by the action of pectin methylesterase in onion. The highest firmness was obtained by pre-heating at $70^{\circ}C$ for 120 min in 0.5% calcium solution. This result was supported by chemical analysis showing that the amount of bound calcium was the highest at $70^{\circ}C$. Further investigation should be carried out to establish the optimal conditions to prevent the softening of various vegetables.

• Childhood Kidney Diseases
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• v.10 no.1
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• pp.8-17
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• 2006

Purpose : We describe the changes of rat glomerular epithelial cells when exposed to high levels of glucose and advanced glycosylation endproducts(AGE) in the in vitro diabetic condition. We expect morphological alteration of glomerular epithelial cells and permeability changes experimentally and we may correlate the results with a mechanism of proteinuria in DM. Methods : We made 0.2 M glucose-6-phsphate solution mixed with PBS(pH 7.4) containing 50 mg/mL BSA and pretense inhibitor for preparation of AGE. As control, we used BSA. We manufactured and symbolized five culture dishes as follows; B5 - normal glucose(5 mM) + BSA, B30 - high glucose(30 mM) + BSA, A5 - normal glucose(5 mM) + AGE, A30 - high glucose(30 mM) + AGE, A/B 25 - normal glucose(5 mM) + 25 mM of mannitol(osmotic control). After the incubation period of both two days and seven days, we measured the amount of heparan sulfate proteoglycan(HSPG) in each dish by ELISA and compared them with the B5 dish at 2nd and 7th incubation days. We observed the morphological changes of epithelial cells in each culture dish using scanning electron microscopy(SEM). We tried the permeability assay of glomerular epithelial cells using cellulose semi-permeable membrane measuring the amount of filtered BSA through the apical chamber for 2 hours by sandwich ELISA. Results : On the 2nd incubation day, there was no significant difference in the amount of HSPG between the 5 culture dishes. But on the 7th incubation day, the amount of HSPG increased by 10% compared with the B5 dish on the 2nd day except the A30 dish(P<0.05). Compared with the B5 dish on the 7th day the amount of HSPG in A30 and B30 dish decreased to 77.8% and 95.3% of baseline, respectively(P>0.05). In the osmotic control group (A/B 25) no significant correlation was observed. On the SEM, we could see the separated intercellular junction and fused microvilli of glomerular epithelial cells in the culture dishes where AGE was added. The permeability of BSA increased by 19% only in the A30 dish on the 7th day compared with B5 dish on the 7th day in the permeability assay(P<0.05). Conclusion: We observed not only the role of a high level of glucose and AGE in decreasing the production of HSPG of glomerular epithelial cells in vitro, but also their additive effect. However, the role of AGE is greater than that of glucose. These results seems to correlate with the defects in charge selective barrier. Morphological changes of the disruption of intercellular junction and fused microvilli of glomerular epithelial cells seem to correlate with the defects in size-selective barrier. Therefore, we can explain the increased permeability of glomerular epithelial units in the in vitro diabetic condition.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.7
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• pp.928-935
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• 2008

The myostatin gene of seven important meat (Beltex (Australia), Beltex$\times$Huyang (F1), Meat and Multi-Prolific Chinese Merino Fine Wool, Meat Chinese Merino Fine Wool and Dorper (South Africa)) and non-meat (Huyang and Kazak) sheep breeds was analyzed to study the genetic basis of muscular hypertrophy (double muscling) phenotype in sheep. SNPs, four in regulatory regions and several in the introns in the myostatin gene, were identified, and the former four SNPs were used for further studies. Twelve haplotypes were predicted by PHASE program, of which four main haplotypes (1, 3, 7, 9) were present in 90% of the 364 sheep in the study. Haplotypes 1-4 were mainly present in meat breeds while haplotypes 7 and 9 dominated the non-meat breeds. The association between haplotypes and average daily gain (ADG) was analyzed among 116 sheep with production data, Haplo2 (CGAA) and Haplo8 (TGAA) were identified to have significant (p<0.05) effect on ADG by the model (JMP5.1 software) taking into account the effects of breed, family background, haplotype, birth weight and sex. ADG of these haplotype groups also correlated well (r = 0.82) with hypertrophic phenotype scores. In conclusion, the mutations -956 (T$\rightarrow$C), -41 (C$\rightarrow$A) and 6223 (G$\rightarrow$A) involved in Haplo2 and 8 may be associated with the double-muscling trait by influencing myostatin function and be suitable markers in selecting meat sheep.

• Journal of Preventive Medicine and Public Health
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• v.27 no.2 s.46
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• pp.200-216
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• 1994

In present study, the authors investigated the possible effect of coffee consumption on serum cholesterol level in 1017 men between the ages of 40 and 59 years, who were randomly selected from the members of Seoul Cohort Study. Serum total cholesterol data was collected with other serologic indices (e.g. systolic blood pressure, diastolic blood pressure, hight, weight, etc.) through the program of biennial health check-up offered by Korean Medical Insurance Corporation (KMIC). The amount of coffee consumption was assessed by a self-administered questionnaire through mailing. Other confounding factors, such as age, body mass index, cigarette smoking, alcohol consumption, physical activity, and other dietary intake pattern were also determined by the questionnaire. The differences in means of serum total cholesterol in compared to non consumers were $-0.4{\pm}3.56mg/dl$ for those drinking less than 1 cup a day, $-0.6{\pm}3.60mg/dl$ for those drinking 1 cup a day, and $7.1{\pm}3.41mg/dl$ for those drinking more than 2 cups a day. Since smoking interacted the relationship between coffee consumption and serum total choleaterol, we re-analyzed those relationship in smokers and non-smokers separately Other atherogenic behaviors were well correlated with total cholesterol, so we adjusted the mean values of serum total cholesterol through multivariate model selection with age(r=0.12), total cigarette index (cigarette-years; r=0.10), Quetelet's index ($Kg/m^2$, r=0.16), daily calory expenditure (kcal/day, r=0.06), weekly meat and poultry consumption(g/week, r=0.05), weekly fish consumption (g/week, r=0.08), other caffeinated beverage intake (cups/week), and the amount of sugar and prim added to the coffee. Among those variables only age, Quetelet's index, fish consumption, and total cigarette index (in smokers) were remained in the models. After adjustment, the corresponing differences of total cholesterol in smokers were changed to $0.4{\pm}5.24mg/dl,\;-0.5{\pm}4.97mg/dl,\;and\;8.9{\pm}4.78mg/dl$, which were significantly different among themselves (P=0.011). In non-smokers, however, the differences were not statistically significant (P=0.76). Adjusted mean values of systolic blood pressure and diastolic blood pressure were also determined to evaluate the direct effect of coffee to cardiovascular system, but their means were not significantly different by coffee consumption(p=0.18 for SBP, p=0.48 for DBP). Asuming instant coffee in the most popular type of coffee in Korea, the association observed in our study between coffee and serum total cholesterol, especially in smokers, is very interesting finding for the connection between coffee and serum total cholesterol, because only 'boiled coffee' tend to show significant lipid raising effect rather than to other types of coffee, like filtered or espresso, in most of the western countries. We concluded that people who drink coffee more than 2 cups a day have significantly higher serum total cholesterol level than those who never drink coffee, especially in smokers.

• Korean Journal of Weed Science
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• v.14 no.3
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• pp.163-170
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• 1994

The experiment was conducted in 1993 to find out a simple prediction method of weeds and to make the prediction models of weeds in paddy fields. The annuals producing fine seeds were apt to emerge at sampling soil only, on the contrary the perennials and the annuals producing large seeds tended not to emerge at sampling soil due to the miss of seeds at sampling. There was no appropriate regression between a total number of weeds emerged at sampling soil and that of weeds occurred in fields. The important annual weeds occurring in fields were able to predict by the number of weeds emerged at sampling soil, but it was difficult to predict the important perennial weeds. In case of Bidens tripartita producing large seeds and Eleocharis kuroguwai producing large tubers, the prediction coefficients were high as above 1.0, and that of Echinochloa crus-galli and Sagittaria pygmaea were comparatively high as 0.175 and 0.172, respectively. However the coefficients of the other weeds were much low as below 0.08. The prediction models for 9 species were made. The model of six species including E. crus-galli, M. vaginalis, R. indica, B. tripartita, E. triandra and S. pygmaea were linear regression with high significance, however that of 3 species including C. difformis, S. juncoides and E. kuroguwai were curve regression with high significance.

• Radiation Oncology Journal
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• v.25 no.4
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• pp.242-248
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• 2007

Purpose: To study the effect of recombinant human epidermal growth factor (rhEGF) on oral mucositis induced by cisplatin and radiotherapy in a mouse model. Materials and Methods: Twenty-four ICR mice were divided into three groups-the normal control group, the no rhEGF group (treatment with cisplatin and radiation) and the rhEGF group (treatment with cisplatin, radiation and rhEGF). A model of mucositis induced by cisplatin and radiotherapy was established by injecting mice with cisplatin (10 mg/kg) on day 1 and with radiation exposure (5 Gy/day) to the head and neck on days $1{\sim}5$. rhEGF was administered subcutaneously on days -1 to 0 (1 mg/kg/day) and on days 3 to 5 (1 mg/kg/day). Evaluation included body weight, oral intake, and histology. Results: For the comparison of the change of body weight between the rhEGF group and the no rhEGF group, a statistically significant difference was observed in the rhEGF group for the 5 days after day 3 of. the experiment. The rhEGF group and no rhEGF group had reduced food intake until day 5 of the experiment, and then the mice demonstrated increased food intake after day 13 of the of experiment. When the histological examination was conducted on day 7 after treatment with cisplatin and radiation, the rhEGF group showed a focal cellular reaction in the epidermal layer of the mucosa, while the no rhEGF group did not show inflammation of the oral mucosa. Conclusion: These findings suggest that rhEGF has a potential to reduce the oral mucositis burden in mice after treatment with cisplatin and radiation. The optimal dose, number and timing of the administration of rhEGF require further investigation.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.15
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• pp.6363-6367
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• 2014

Purpose: This study was conducted to assess the preventive effect of Actinidia valvata Dunn (AVD) extract on an animal model of gastrointestinal carcinogenesis on the basis of changes in tumor incidence, cell proliferation, and apoptosis. Materials and Methods: Seventy-five male Wistar rats were divided into five different treatment groups with 15 rats in each group. Group I was given normal feed, whereas Groups II to IV were treated with 10% sodium chloride in the first six weeks and 100ug/mL of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in drinking water for 24 weeks. Group II was then given normal feed, whereas Group III was given AVD extract (0.24g/kg/day) for 12 weeks. Group IV was given AVD extract from the first week to the 36th week, whereas Group V was treated with AVD extract alone for 36 weeks. All rats were sacrificed at the end of the 36-week experiment and assessed for the presence of gastrointestinal tumors. The occurrence of cancer was evaluated by histology. Bax, Bcl-2, Caspase-3, and cyclinD1 were determined by immunohistochemical staining and Western blotting. Results: The incidences of gastric cancer were 0% in Group I, 73.3% in Group II, 33.3% in Group III, 26.7% in Group IV, and 0% in Group V. Bcl-2 and cyclinD1 expression was decreased in AVD extract treated groups, whereas Bax and Caspase-3 expression was increased. Comparison with group II revealed significant differences (p<0.01). Conclusions: AVD extract exhibits an obvious preventive effect on gastrointestinal carcinogenesis induced by MNNG in rats through the regulation of cell proliferation and apoptosis.