• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.3
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• pp.348-353
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• 2003

Early detection and prudent management of mesiodens or supernumerary tooth should be considered essential in reducing disturbance in the eruption and position of the adjacent permanent incisor. While it is true that the presence of diastema may be regarded as normal at the early mixed dentition stage, the early detection and removal of the mesiodens is a prerequisite to facilitate spontaneous alignment or subsequent approximation of the permanent central incisors. In many cases, diastema due to mesiodens can be physiologically corrected spontaneously after the extraction of mesiodens. The best choice of treatment of diastema may be observation. Orthodontic intervention is required only spontaneous closing of diastema does not occur within observation period. In orthodontic intervention, careful treatment plan should be established. Clinician gives considerations to angulation of central and lateral incisor, proximity of lateral incisor, developmental stage and position of canine, pattern and extent of anterior crowding. Orthodontic movement should be done slowly with light force. In addition, periodic radiographic observation are needed to monitor the root development and root resorption. Case 1, 2 and 3 showed physiologic closures after the extraction of mesiodens. In these cases, acceptable alignment of central and lateral incisors was obtained. In case 4, orthodontic correction for diastema was performed successfully after the extraction of mesiodens. After the orthodontic closure of the diastema, it was decided that a retainer was not needed, because the dentition was under a dynamic stage in exchanging teeth and also developing arches.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.5
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• pp.445-450
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• 2006

The nitrogen fertilization effect on growth characteristics and isoflavone content was investigated in this study, and isoflavone analyzed by HPLC with photodiode array (PDA) detector and reverse-phase $C_{18}$ column. Fertilization levels were no-fertilization, no nitrogen, 50% decreased in nitrogen, standard and 50% increased in nitrogen fertilization. The 50% increased nitrogen fertilization showed the highest growth characteristics then other fertilization level and the number of pod and seed showed maximum value 31.9 and 72.3, respectively, and seed yield was 2,460 kg/ha. During growth stages, isoflavone content in leaf, stem and root of soybean plants decreased to R5 stage then increased to R7 stage. Isoflavone content according to various nitrogen fertilization condition, in case of none fertilization, no nitrogen, 50% decreased nitrogen fertilization showed higher value than those of standard and 50% increased nitrogen fertilization levels. Aglycon content among the isoflavone isomers showed much higher in plant than in seed. The highest isoflavone content was found in the root of soybean plant parts. Isoflavone content of seed was higher in none, no nitrogen, 50% decreased nitrogen than those of standard and 50% increased nitrogen fertilization.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.736-745
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• 2016

This research was conducted to evaluate the impact of various pre-planting $NH_4{^+}:NO_3{^-}$ ratios on the growth of plug seedlings of 'Bool-am No.3' Chinese cabbage. With fixation of the pre-planting N concentrations to $300mg{\cdot}kg^{-1}$ in a peatmoss+coir dust+perlite (3.5:3.5:3, v/v/v) medium, the $NH_4{^+}:NO_3{^-}$ ratios were varied to 0:100, 27:73, 50:50, 73:27, 100:0. Then, the each of root media containing various ratios of $NH_4{^+}:NO_3{^-}$ as well as equal concentrations of other essential nutrients was packed into 72-cell plug trays. After seeds of 'Bool-am No.3' Chinese cabbage were sown, the seedling growths were measured 2 and 4 weeks after sowing. The weekly analysis of root media and end-crop tissue analysis for mineral nutrients 4 weeks after seed sowing were also conducted. As the seedlings grew up, the pH of the root media increased, however ECs in all treatments of $NH_4{^+}:NO_3{^-}$ ratios decreased. The concentrations of K, Ca and Mg in root media were higher in the treatments of $NH_4{^+}:NO_3{^-}$ (100:0) and $NH_4{^+}:NO_3{^-}$ (73:27) than those of $NH_4{^+}:NO_3{^-}$ (0:100) and $NH_4{^+}:NO_3{^-}$ (27:73) 2 weeks after seed sowing. But the concentrations of K, Ca, Mg and Zn were get lowered in all treatments and the differences among treatments were not significant 4 weeks after sowing. The highest $NH_4{^+}$ and lowest $NO_3{^-}$ concentrations of the root media were observed in the $NH_4{^+}:NO_3{^-}$ (100:0) among all treatments. Contrary to these, the treatment of $NH_4{^+}:NO_3{^-}$ (0:100) had the lowest $NH_4{^+}$ and highest $NO_3{^-}$ concentrations. The seedling growth in terms of fresh and dry weights of aerial part were the highest in the treatment of $NH_4{^+}:NO_3{^-}$ (23:73) at 2 weeks after sowing and those of $NH_4{^+}:NO_3{^-}$ (50:50) at 4 weeks after sowing. The survival rate of seedlings in $NH_4{^+}:NO_3{^-}$ (100:0) treatment were 19% and the growth of aerial part 4 weeks after sowing was the poorest among all treatments tested. The results mentioned above indicate that the pre-planting $NH_4{^+}$ ratio in inert media should not exceed 25% in plug stage 1 through 3 (until 2 true leaf development) and 50% in plug stage 4 (after 2 true leaves to transplant).

• Journal of Periodontal and Implant Science
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• v.37 no.1
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• pp.35-44
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• 2007

Periodontal ligament (PDL) is the connective tissue located between the tooth root and alveolar bone. In a previous study, PDLs22 was isolated as a PDL-specific gene by using subtractive hybrid-ization between cultured PDL fibroblasts and gingival fibroblasts. It was also suggested that PDLs22 plays important roles in the development, differentiation and maintenance of periodontal tissues. However, little is known about functional study of PDLs22 using recombinant protein in PDL fibroblast differentiation and periodontium formation. In this study, in order to produce the PDLs22 recombinat protein, PDLs22 expression vector were constructed and expressed its protein in various host cell and temperature conditions. The results were as follows: 1. PDLs22 protein was not strongly expressed In the induction system using pRSET-PDLs22 construct. 2. When the BL21(DE3) pLysS was used as a expression host, PDLS22 protein was strongly ex-pressed in the induction system using pHCEIIBNd-PDLs22 construct. 3. The PDLs22 protein was recognized at a molecular weight of 28 kDa in western blots. 4. Almost of the expressed PDLs22 protein was not soluble and observed like as inclusion body. 5. The protein solubility was not improved after modification of induction time and temperature during PDLs22 protein production. In this study, the system for the PDLs22 protein production was connstructed. However, the re-results suggest that further studies will be needed to produce the considerable amount of PDLs22 re-combinat protein, which can use for the periodontal regeneration.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.522-527
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• 2004

Barley growing in paddy fields often suffers from wet-injury due to oxygen deficiency in rhizospere caused by excessive water in the soil. This study was conducted to investigate responsiveness of growth, development and anaerobic glycolysis enzymes to acute hypoxia in barley seedlings. Barley seedlings at the third leaf stage were subjected to hypoxia (1 ppm dissolved oxygen) by sparging the culture solution with nitrogen gas for up to seven days. Length and fresh weights of the shoot and root were affected little by hypoxia for up to 5 days. But root dry weight was slightly decreased by hypoxia for 7 days. In the root, alcohol dehydrogenase and lactate dehydrogenase activities increased drastically under hypoxia, reaching at their maximum levels in 3 to 5 days of hypoxia and decreasing slightly thereafter. However, the activities of both enzymes changed little in the shoot. Increases of their activities in the root were contributed by all the isozymes found in barley. These results suggest that barley seedlings first adapt to hypoxia by rapidly activating fermentative glycolysis to stabilize cellular pH and to increase energy production for the following morphological adaptative changes.

• Korean Journal of Food Science and Technology
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• v.13 no.2
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• pp.133-141
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• 1981

The gelatinization phenomena of bracken root starch were examined by means of the loss of birefringence, degree of digestibility by amylase and X-ray diffraction. These results indicated that gelatinization temperature of the starch was $55{\sim}60^{\circ}$ and over 95% of starch were gelatinized at the temperature between 60 and $70^{\circ}C$. The swelling power of the bracken root starch was much less steeper than that of potato or tapioca starch. Amylograph data on the various starch concentrations showed the pasting temperature of $62{\sim}68^{\circ}$, peak height of $80{\sim}840$ Brabender unit (BU) and peak after cooling to $50^{\circ}C$ of $110{\sim}555\;BU.$. According to the information obtained from amylograph data, the bracken root starch showed low set back. The rate of retrogradation of the starch as tested by Texturometer was slower and faster than that of potato and tapioca starches, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.1
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• pp.89-93
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• 1997

To determine the optimum levels of soil phosphorus and potassium for the carrot growth and to investigate the relationship between the quality of carrot root and, P and K contents in soil, carrot was planted in $1m^2$ bottomless pot with five levels of P and K. Maximum root weight was harvested in the plots with 425mg/kg of available P as $P_2O_5$ and $0.72cmol^+/kg$ of exchangeable potassium as K in soil at carrot shoot elongation stage. The concentrations of P and K in harvested carrot root were high in the plots with 359-396 mg/kg of available $P_2O_5$ and $0.79-0.87cmol^+/kg$ of exchangeable K. Sugar content in carrot root increased to available $P_2O_5$ 284 mg/kg in soil and it decreased as soil potassium increased.

• The Plant Pathology Journal
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• v.32 no.3
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• pp.228-241
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• 2016

In our previous study, we reported that a novel endophytic bacterium Bacillus oryzicola YC7007 has suppressed bacterial diseases of rice via induced systemic resistance and antibiotic production. This endophytic strain, B. oryzicola YC7007 was used as a biological control agent against bakanae disease of rice caused by Fusarium fujikuroi, and its mechanism of interaction with the pathogen and the rice was further elucidated. Root drenching with B. oryzicola YC7007 suspension reduced the disease severity of bakanae significantly when compared with the untreated controls. The treatments of B. oryzicola YC7007 suspension ($2.0{\times}10^7cfu/ml$) to the rice rhizosphere reduced bakanae severity by 46-78% in pots and nursery box tests containing autoclaved and non-autoclaved soils. Moreover, in the detached rice leaves bioassay, the development of necrotic lesion and mycelial expansion of F. fujikuroi were inhibited significantly by spraying the culture filtrate of B. oryzicola YC7007. Drenching of ethyl acetate extracts of the culture filtrate to the rhizosphere of rice seedlings also reduced the bakanae disease severity in the plant culture dish tests. With the root drenching of B. oryzicola YC7007 suspension, the accumulation of hydrogen peroxide was observed at an early stage of rice seedlings, and a hormonal defense was elicited with and without pathogen inoculation. Our results showed that the strain B. oryzicola YC7007 had a good biocontrol activity against the bakanae disease of rice by direct inhibition, and was also capable of inducing systemic resistance against the pathogen via primed induction of the jasmonic acid pathway.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.339-344
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• 2008

When a delayed eruption of tooth is diagnosed, the causative factor should be detected before an establishment of treatment plan, if possible. Although a panoramic radiograph is enough to evaluate the position of tooth and the stage of tooth development, a 3-D Dental CT would be a powerful tool to reveal a spatial relationships between objects. The reported case showed a delayed eruption of lower left permanent canine and a mini-plate with screws adjacent to the impacted canine. Although the screws adjacent to the root of impacted tooth showed a close proximity, it was not presumed that these screws would interfere the eruption of the tooth. The impacted canine did not show any spontaneous eruption during observation. After the mini-plate and screws were removed, an orthodontic traction using elastic power chain was performed. The position of mini-plates and screws should be carefully designed to avoid damaging the tooth follicles or tooth roots in the jaw. Also the screws should be removed before an orthodontic traction to prevent damaging the root surface of impacted tooth.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.1
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• pp.53-65
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• 2001

To estimate agricultural water demand, many factors such as weather, crops, soil, cultivation method, crop coefficient and cultivation area, etc. must be considered. But it is not easy to estimate water demand in consideration of these factors, which are variable according to growth stage and regional environment. This study provides estimation system for agricultural water demand(ESAD) in order to estimate water demand easily and accurately, and arranges all factors needed for water demand estimation. This study identifies the application of estimation system for agricultural water demand with the data observed in the other studies, and analyzes nationwide agricultural water demand. The results are as follows. 1) The practice of different rice cultivation in the paddy field resulted in different water demands. Water depth and infiltration ratio in paddy are the most important factors to estimate water demand. The water depths in paddy simulated by ESAD is very similar to the observed ones. 2) Water demand of upland crops varies with the crops, soil, etc.. Effective rainfall estimated by daily routing of soil moisture varies according to the crops, soil, and effective soil zone(root depth). As crop root become grown, effective rainfall and an amount of irrigation water has been increased. 3) The current unit water demand of upland crops applied as 500mm or 550mm to estimate water demand does not reflect the differences caused by the crops, regional surrounding, weather condition, etc. Results from ESAD for the estimation of water demand of upland crops show that ESAD can simulate the actual field conditions reasonably because it simulates the actual irrigation practices with the daily routing of soil moisture.