• Korean Journal of Soil Science and Fertilizer
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• v.27 no.3
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• pp.226-231
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• 1994

This experiment was conducted to evaluate the effect of coated urea complex fertilizer(CUC) on the growth and quality of rice in high-ridged dry seeding and infant -seedling machine transplanting on clay loam and sandy loam in Milyang, Korea, 1993. The CUC level applicated was 100 %, 80 %, 60% and 40% to standard application amount of fertilizer. Results obtained were as follows : 1. The nitrogen releasing rate in dry seeding was 83% for sandy loam, 81% in clay loam for 3.5 months after initial releasing, and in infant-seedling was 89% in both soil types for 4 months. 2. The degree of rice leaf color was the highest at the heading stage, and was high with increasing CUC application level regardless of cultural methods, especially was higher at harvesting stage in the 100% level of CUC to standard application amount of fertilizer than conventional fertilizer. 3. The perfect rice grain ratio was higher in infant-seedling than in dry seeding, but lowered with increasing CUC application level regardless of cultural methods. The green kerneled rice ratio among imperfect rice grain was high in dry seeding, and the notched belly rice kernel ratio was high in infant-than infant-seedling of the both soil types, and increased with increasing CUC application level. 4. Hon-value in rice grain was higher at the treatment of CUC application than conventional fertilizer in dry seeding. However, it was contrary result in infant seedling, and was low tendency with decreasing CUC application. On the other hand, the protein in rice grain was also same tendency of Hon-value. Cel-consistency related to eating quality was longer with increasing CUC application level regardless of cultural methods. However, there was no clear tendency at clay loam. 5. No significant difference between rice yield and CUC application in the range of 60% to 100% at both soil types in dry seeding was observed. These results appeared in clay loam under infant seedling except sandy loam. Accordingly, it was thought that 60% level of CUC to standard application amount of fertilizer could be applicated for growth and quality of rice.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.5
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• pp.318-324
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• 2000

Field experiment was conducted on a sandy clay loam paddy field in the Experimental Farm of the Kangwon National University for four years from 1995 to 1998 to evaluate the effect of different nitrogen fertilizers on soil property and rice yield. The size of each experimental plot was 75 m2. Basal application of fertilizer to the paddy field was on late April, and rice (cv. Odae) was sown with drill seeding on early May. Irrigation was done at 3 leaf stages after rice seeding. Electrical conductivity in soils treated with phosphate- and resin coated slow release fertilizers were relatively greater than those of the other fertilizer application. Available $P_2O_5$ concentration in soils after rice harvest increased significantly compared that in soil before field trial. Rice yield in transplanting culture were $6.516kg\;ha^{-1}$. The rice yield in the direct seeded paddy was 81.9 percents of the yield in the transplanted paddy. The rice yield in phosphate coated slow release fertilizer was the highest among various fertilizer trials in directly seeded dry paddy, while rice yield was the lowest in the organic fertilizer plus urea application. Rice yield between organic fertilizer plus urea and organic fertilizer application were not significantly different. The green manuring effect of rye in the direct seeded rice paddy in Chuncheon was low due to low temperature and short growth period.

• Clinical and Experimental Reproductive Medicine
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• v.35 no.4
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• pp.247-265
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• 2008

Objectives: Many types of liver diseases can damage regenerative potential of mature hepatocytes, hepatic progenitor cells or oval cells. In such cases, a stem cell-based therapy can be an alternative therapeutic option. We examined whether human amnion-derived mesenchymal stem cells (HAM) and human umbilical cord-derived stem cells (HUC) could differentiate into hepatocyte-like cells as therapeutic cells for the liver diseases. Methods: HAM and HUC were isolated from the amnion and umbilical cord of the volunteers after a caesarean section with informed consent. In order to differentiate these cells into hepatocyte-like cells, cells were cultivated in hepatogenic medium using culture plates coated with fibronectin. Effects of hepatocyte growth factor, L-ascorbic acid 2-phosphate, insulin premixture fibroblast growth gactor 4, dimethylsulfoxide, oncostatin M and/or dexamethasone were examined on the hepatic differentiation. After differentiation, the cells were analyzed by RT-PCR, immunocytochemistry, immunoblotting, albumin ELISA, urea assay and periodic acid-schiffs staining. Results: Initial fibroblast-like appearance of HAM and HUC changed to a round shape during culture in the hepatogenic medium. However, in all hepatogenic conditions examined, HUC secreted more amounts of albumin or urea into medium than HAM. Expression of some of hepatocyte-specific genes increased and expression of new genes were observed in HUC following cultivation in hepatogenic medium. Results of immunocytochemistry and immunoblotting analyses demonstrated that HUC secreted albumin into the culture medium. PAS staining further demonstrated that HUC could store glycogen inside of the cells. Conclusions: Both HUC and HAM could differentiate into albumin-secreting, hepatocyte-like cells. Under the same hepatogenic conditions examined, HUC more efficiently differentiated into hepatocyte-like cells compared with the HAM. The results suggest that HUC and HAM could be used as sources of stem cells for the cell-based therapeutics such as in liver diseases.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.4
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• pp.216-222
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• 2002

Field experiments were conducted to investigate the effect of various cultural practices on methane($CH_4$) emission in tillage and no-tillage practice in a clayey paddy soil from 1998 to 2000. The factors evaluated in tillage and no-tillage methods were types of nitrogen fertilizers, application method of chemical fertilizers, rice straw application and cultivation method. Of the nitrogen fertilizers, the amount of $CH_4$ emission in ammonium sulfate plot was the lowest, regardless of tillage and the application method. 26.4~41.1% of reduction by ammonium sulfate compared with urea. But in no-tillage which have problem of poor rice yield than tillage, coated urea was more effective nitrogen fertilizer because that showed similar $CH_4$ emission and highest rice yield at 80% of dosage of nitrogen. No-tillage plot emitted lower $CH_4$ than tillage plot where the fertilizers were incorporated. On the contrary, no-tillage plot showed a little higher $CH_4$ emission compared with tillage plot for the surface application. When rice straw was applied, no-tillage practice reduced methane emission by 26.6% compared with tillage practice, but showing a little difference of 10.7% in no application. With cultivation method, no-tillage practice reduced methane emission 26.6% compared with tillage for the 30-d-old seedling transplanting. But for the dry direct seeding practice, no-tillage was a less effective because considerable amounts of rice straw incorporated by tillage were more decomposed aerobically in the soil and emitted as $CO_2$ to the atmosphere with flooding in no-tillage soil.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.254-260
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• 1999

This experiment was carried out to evaluate the effect of improvement of soil physical property such as deep plowing and chiseling and diagnostic application of N, P, K fetilizers. Latex Coated Urea(LCU), compost, sillicate for increasing yielding and enchancing N-use efficiency in puddled-soil drill seeding of Rice. The soil physical properties, such as bulk density, hardness and porosity were increased by deep plowing and chiseling, as well as chemical propeties were highly enhanced soil productivity due to increase the content of organic matter, available $P_2O_5$ and K as compare with control. The amount of $NH_4-N$ in soil was highly increased by diagnostic fertilization and chiseling, while recovery rate of V fertilizer was the highest at LCU 80% applied with chiseling. The rice yield increased by 23% under the diagnositic application of LCU 80% applied base with chiseling.

• Applied Biological Chemistry
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• v.25 no.4
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• pp.232-238
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• 1982

From ^{15}N$ labelled nitrogen experiments on 13 fields use efficiency by difference method was higher than that by labelling method in 80% of fields tested indicating augmentation of soil nitrogen uptake by fertilizer nitrogen. Both methods showed very similar trend among fields. Sulfur coated urea(SCU) and point application increased fertilization efficiency(yield increment per fertilizer nitrogen applied, Fe) to 23 from 15 of split application through the increase of fertilizer use efficiency from 29(Eu) to 50 but tended to decrease efficiency of absorbed fertilizer nitrogen(yield increment per nitrogen derived from fertilizer, Ef) from 50. to 46 High yielding capacity of Tongil line appears to be attributed to the higher Ef, translocation efficiency and soil nitrogen preference index(soil nitrogen increment in plant per the increment of fertilizer nitrogen in plant, PI). This studies confirmed that yield under fertilizer application system depends on Fe which is the multiplication of Eu and Ef and that the improvement of fertilizer management(form, application method and time) increases principally Eu, the limit of which is controlled by Ef that is attributed mainly to varietal characteristics.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.6
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• pp.334-338
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• 2006

This study was conducted to evaluate the effect of improvement of soil physical properties such as deep plowing, subsoil breaking and diagnostic fertilization on the yield of rice and nitrogen-use efficiency in direct seeding on flooded paddy surface of rice. The effects of deep plowing, subsoil breaking and diagnostic application of N, P, K fertilizers, Latex coated urea(LCU), compost, silicate were investigated. The soil physical properties, such as bulk density, hardness and porosity were improved and the content of organic matter and available $SiO_2$ were also increased by deep plowing and subsoil breaking. The amount of $NH_4-N$ in soil was highly increased by diagnostic fertilization and deep plowing at 5th leaf stage. The nitrogen-use efficiency was the highest at the diagnostic application of LCU 70% applied as basal dressing with subsoil breaking. The yield of rice increased by 8% under the diagnostic application of LCU 70% applied as basal dressing with subsoil breaking compared with the conventional application.

• Journal of Chest Surgery
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• v.32 no.2
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• pp.97-107
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• 1999

Background: This study was designed to develop a Korean version of the heparin-coated vascular bypass shunt by using a physical dispersing technique. The safety and effectiveness of the thrombo-resistant shunt were tested in experimental animals. Material and Method: A bypass shunt model was constructed on the descending thoracic aorta of 21 adult mongrel dogs(17.5-25 kg). The animals were divided into groups of no-treatment(CONTROL group; n=3), no-treatment with systemic heparinization(HEPARIN group; n=6), Gott heparin shunt (GOTT group; n=6), or Korean heparin shunt(KIST group; n=6). Parameters observed were complete blood cell counts, coagulation profiles, kidney and liver function(BUN/Cr and AST/ ALT), and surface scanning electron microscope(SSEM) findings. Blood was sampled from the aortic blood distal to the shunt and was compared before the bypass and at 2 hours after the bypass. Result: There were no differences between the groups before the bypass. At bypass 2 hours, platelet level increased in the HEPARIN and GOTT groups(p<0.05), but there were no differences between the groups. Changes in other blood cell counts were insignificant between the groups. Activated clotting time, activated partial thromboplastin time, and thrombin time were prolonged in the HEPARIN group(p<0.05) and differences between the groups were significant(p<0.005). Prothrombin time increased in the GOTT group(p<0.05) without having any differences between the groups. Changes in fibrinogen level were insignificant between the groups. Antithrombin III levels were increased in the HEPARIN and KIST groups(p<0.05), and the inter-group differences were also significant(p<0.05). Protein C level decreased in the HEPARIN group(p<0.05) without having any differences between the groups. BUN levels increased in all groups, especially in the HEPARIN and KIST groups(p<0.05), but there were no differences between the groups. Changes of Cr, AST, and ALT levels were insignificant between the groups. SSEM findings revealed severe aggregation of platelets and other cellular elements in the CONTROL group, and the HEPARIN group showed more adherence of the cellular elements than the GOTT or KIST group. Conclusion: Above results show that the heparin-coated bypass shunts(either GOTT or KIST) can suppress thrombus formation on the surface without inducing bleeding tendencies, while systemic heparinization(HEPARIN) may not be able to block activation of the coagulation system on the surface in contact with foreign materials but increases the bleeding tendencies. We also conclude that the thrombo-resistant effects of the Korean version of heparin shunt(KIST) are similar to those of the commercialized heparin shunt(GOTT).

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.5
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• pp.292-297
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• 2006

A research was carried out to investigate the release pattern of slow release nitrogen fertilizer compound(SRNC) that is latex coated urea(LCU) and to recommend the application rate of the fertilizer at dry seeding rice culture in Honam plain area. The experiment was conducted at experimental field(Jeonbug series, fine silty, mixed, nonacid, mesic family of Fluvaquentic Endoaquepts) of National Honam Agricultural Research Institute. A medium late maturing rice variety (Dongjinbyeo) was seeded at the rate of $60kg\;ha^{-1}$ by drill seeder on April 1, 1997 and March 30, 1998. Fertilizer application rate was $160-90-110kg\;ha^{-1}$ for $N-P_2O_5-K_2O$. Soil ammonium nitrate($NH_4-N$) contents remained higher in all SRNC plots than conventional ones and higher with the increase of SRNC application rate until panicle formation stage, but the contents was higher in the conventional than NRNC plots at the heading stage. The plant hight was taller in SRNC than conventional plots until maximum tiller stage, but became similar in both conventional and SRNC plots at heading stage. The culm and panicle number was greater in SRNC than conventional plots throughout all growth stage, but the effective tiller rate was higher in conventional ones. Nitrogen efficiency was higher in the SRNC than conventional plots, but the efficiency was decreasing with the higher SRNC level. The spikelet number per unit area was greater in SRNC than conventional plots, and increased with higher SRNC level. The more spikelet number with higher NRNC level resulted in lower 1,000-grain weight. The rice yield in conventional plot was similar with only 60% SRNC level, but lower than 80% and 100% SRNC levels. However, slight lodging was observed in 100% SRNC level. In conclusions, we recommend NRNC application level as 80% of standard nitrogen application for early dry seeding culture of rice Honam plain area.