• Journal of Oral Medicine and Pain
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• 제6권1호
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• pp.15-18
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• 1981

The author had selected the roots and root-canal as measurable parts and sought the area ratio by measuring the respective areas of the root. Further, heplotted out a root caual index and studied the correlation with age. The teeth used as reserch material were permanent maxillary central incisors of Korean female. Some 296 teeth of known age were selected on condition that there is no caries or filling material and that they were not malformed in showing normal signs in roentgenograms. The $3" {\times} 4"$ printing paper so as to measure easily. On the ocassion of measureing the area of measured parts with a planimeter (Koizumi, type kp-27, Japan), the cervical lines were joined up into a straight line on a photograph (Figure 1) Root canal index = Area of the root / Area of the root canal The results of the root canal index in Korean female age groups were as follows : 1. The root canal index of maxilary central incisor in women was 4.74 im 20 years of age, 5.44 in 30, 5.90 in 40, 6.32 in 50, 6.63 in 60 in the order. 2. Root canal index and age were in positive correlation ; there was a tendency that the root canal index increase as age advances. 3. The regression equation was as follows : Y = 5.36x + 7.71 (r = 0.54, n= 296 ) (Y = estimated age, x = root canal index)

• 한국조경학회지
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• 제28권4호
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• pp.1-8
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• 2000

This study is conducted to evaluate the effects of root restriction on growth of maple(Acer palmatum Thumb.). Tow types of container such as clay pot(CP), root control bag(RCB) were used to restrict maple's root and each type of container was divided into 5 sizes. The containers with plants were buried just below the soil level and maples planted directly in the soil (nonrestricted root treatment) were included as comparison. Data were collected on dry weight of leaf, trunk, thick root, rootlet and soil water potential. We have analyzed, simple linear regression, Pearson's Correlation analysis, Duncan's multiple rang test, and Covariance Analysis using SAS statistical software. The results of analysis based on these data are as follows; 1. Total dry weight of maple in CP was significantly larger than in RCB. 2. Difference in growth reduction by the kinds of containers was induced by different hydraulic diffusion ratios between container and soil. Difference in growth reduction by the size of container was induced by the difference density of rootlet and soil moisture contents in the container. 4. Commercial products of root control of root control bag appeared not proper for countries in which fluctuation of rainfall is severe. Because maples in RCB were restricted by excess soil water in the rainy season, or by lack of soil water in the dray season.

• 식물병과 농업
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• 제5권2호
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• pp.84-89
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• 1999

Development of root galls of clubroot disease on Chinese cabbage seedlings was first observed 17days after inoculation of Plasmodiophora brassicae at $25^{\circ}C$ 4-11days earlier than at 5, 20, 3$0^{\circ}C$ and 35$^{\circ}C$. Subsequent enlargement of root galls was also fastest at $25^{\circ}C$ and 2$0^{\circ}C$ but delayed at 15$^{\circ}C$ and 3$0^{\circ}C$ or above. Chinese cabbage seedlings with root gall formation showed reduction in number of leaves above ground fresh weight and amount of root hairs but increase in root weight, Root galls development was highest at soil moisture level of 80% of maximum soil moisture capacity than at 60% and 100%. Optimum soil pH for root gall development was pH 6 although root galls were formed at a range of pH 5 to 8. Period of light illumination also affected root gall development with the greatest gall development at 12hr/12hr in light/dark period and the least at 8hr/16hr. Site of root gall formation and gall shape did not differ greatly among treatments of temperature soil moisture pH and light experiments.

• 대한치과의사협회지
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• 제19권7호통권146호
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• pp.625-634
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• 1981

A Scanning Electron Microscopic Study of the root surface changes was carried out in advanced periodontal disease. The results obtained were summerized as follow; 1. The root surface of cementoenamel junction of healthy root showed smooth surface, while the root surface of diseased state showed covering of deposits which regareded as a course of calcification. 2. At the mid-portion of the root, the regular cemental projection were observed on the healthy root surface and on the root surface of diseased state, cemental projection showed relatively irregular pattern. 3. On the root surface which consist of wall of periodontal pocket, there were various deposits which could be considered as subgingival calculus, bacterial plaque and epithelial attachment remnant. 4. The bottom area of the pathologic pocket, tearing altered collagen fibers were seen on the root surface. 5. At the apical portion of root surface, calcified fibers ran parallel to the root surface in healthy tooth and the fiber bundles of periodontal ligament were seen in the diseased state.

• 농업과학연구
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• 제47권2호
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• pp.305-313
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• 2020

Root hair development has the potential to increase crop yields and at the same time to decrease fertilizer use, which will be required in the next 30 years to meet the demand for crop-derived commodities in a world with decreasing available natural resources. Root hair defective six (RHD6) encoding a basic helix-loop-helix transcription factor, is associated with root hair differentiation, and its roles are root hair initiation and elongation. Grass plants, rice and Brachypodium have been used as model plants to study the gene function of the root hair defective six like (RSL) subfamily which is orthologous to AtRHD6. The RSL subfamily has an identical gene function with AtRHD6 which is involved with root hair differentiation as well. Plants with longer root hairs within a species should have an improved Pi uptake efficiency; therefore, we would expect that a plant with a high Pi uptake could contribute to increasing the plant yield. We achieved increased root hair length by manipulating the RSL subfamily genes. It is expected that in these transgenic plants, the long root hairs would be sufficient to improve the Pi uptake and hence improve biomass and yield component (tiller, spikelet number, and spikelet weight) of the plant. Here, we demonstrate that Brachypodium transgenic plants overexpressing the BdRSL subfamily genes have an improved biomass and grain yield. The result of this study could be applied to important crop plants like rice.

• Journal of Ginseng Research
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• 제17권1호
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• pp.45-51
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• 1993

In 61 abolished ginseng fields examined in 1986, the average plant missing was 49.2%, root rusting, 34.4%, and root rot, 3.3%. Plant missing was not different among the ages of ginseng fields; however, rate of root rusting was high in 3- and 4-year-old ginseng fields, and rate of root rot was high in 5- and 6-year-old ginseng fields, suggesting that root rusting and root rot were relatively more important factors related to the abolishment of ginseng filed in younger and older ginseng fields in 1986, respectively. Out of 61 ginseng fields, 18 were infested with more than 509) alternaria blights, and out of 19 fields with root rot, 2 were caused by Sclerotinia sp., 5 by potato rot nematode, and the causal agents were not identified in 12 fields. With increase of the ridge height, root rusting was significantly decreased, and plant missing rate was significantly lower in fields with straw mulching than those without mulching. The physico-chemical characteristics of the fields with more than 50fi root rusting, the contents of $NO_3,\;P_2O_5$ and Ca were higher than those of good fields with less than 40% root rusting and plant missing. The population of Erwinia sp. was significantly corralled with plant missing.

• Restorative Dentistry and Endodontics
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• 제7권1호
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• pp.17-24
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• 1981

The purpose of this study is to compare the shape of the apical regions of root canals after instrumentation by various enlarging instruments. 120 extracted, single-rooted human teeth were seperated into 4 experimental groups. Each group provided 30 teeth for experimental use. Group 1 root canals instrumented by the hand-operated Reamer. Group 2 root canals instrumented by the hand-operated H-file. Group 3 root canals instrumented by the hand-operated K-file. Group 4 root canals instrumented by the automated Giromatic file. The results were as follows: 1. The degree of the roundness of the apical regions of root canal walls: 1) Hand-operated instruments were superior to the automated Giromatic file. 2) The Reamer was the most effective instrument among hand-operated instruments 3) There was little difference between the H-file and the K-file. 2. The degree of the smoothness of the apical regions of root canal walls: 1) Root canal walls instrumented by the hand-operated Reamer, H-file and, K-file were generally smooth, and there was little difference among them. 2) Root canal walls instrumented by the automated Giromatic file showed many irregular canal walls. 3. The existance of organic debris in the apical regions of root canals: All organic debris is not removed from root canals, and there was little difference between hand-operated instruments and the automated Giromatic instrument in removing organic debris.

• Restorative Dentistry and Endodontics
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• 제7권1호
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• pp.59-63
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• 1981

Ninety four human mandibular third molars were chosen to study the anatomy of the root canal. The experimental teeth were injected with china ink, decalcified, cleared and used in study, in vitro, to determine the number of root, the number of root canals, canals per root, frequency and location of transverse anastomoses, frequency and location of lateral canals and frequency of the apical deltas. The results were as follows: 1. Most of the teeth showed two canals, but 17.0% of the teeth were found to have one canal, 17.0% of them three canals, 3.2% of them four canals and l.1% of them five canals. 2. In so far as observing one canal per root, 17.0% of the teeth were found to have one canal in single-rooted tooth, 48.9% of them in mesial root and 58.5% of them in distal root. 3. In roots with two or three canals, the separated apical foramen appeared in 55.6% in single-rooted tooth, 64.3% in mesial side and 80.0% in distal side, and the common apical foramen appeared in 44.4% in single-rooted tooth, 35.7% in mesial side and 20.0% in distal side. 4. Of the two root canals in one root, 19.1% of the canals were found to have transverse anastomoses and were usually located in the apical third of the root. 5. 63.8% of 94 teeth were found to have lateral canals, and ramifications were mainly located in the apical third of the root.

• Restorative Dentistry and Endodontics
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• 제41권1호
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• pp.55-62
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• 2016

Objectives: The purpose of this study was to investigate the incidence of root fusion and C-shaped root canals in maxillary molars, and to classify the types of C-shaped canal by analyzing cone-beam computed tomography (CBCT) in a Korean population. Materials and Methods: Digitized CBCT images from 911 subjects were obtained in Chosun University Dental Hospital between February 2010 and July 2012 for orthodontic treatment. Among them, a total of selected 3,553 data of maxillary molars were analyzed retrospectively. Tomography sections in the axial, coronal, and sagittal planes were displayed by PiViewstar and Rapidia MPR software (Infinitt Co.). The incidence and types of root fusion and C-shaped root canals were evaluated and the incidence between the first and the second molar was compared using Chi-square test. Results: Root fusion was present in 3.2% of the first molars and 19.5% of the second molars, and fusion of mesiobuccal and palatal root was dominant. C-shaped root canals were present in 0.8% of the first molars and 2.7% of the second molars. The frequency of root fusion and C-shaped canal was significantly higher in the second molar than the first molar (p < 0.001). Conclusions: In a Korean population, maxillary molars showed total 11.3% of root fusion and 1.8% of C-shaped root canals. Furthermore, root fusion and C-shaped root canals were seen more frequently in the maxillary second molars.

• 한국식품저장유통학회지
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• 제16권1호
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• pp.53-59
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• 2009

The purpose of this research is to develop bellflower (Platycodon grandiflorum) root and lotus (Nelumbo nucifera) root Jeonggwa as a health food. The quality characteristics of Jeonggwa to which 0-8% (w/w) of Omija (Schizandra chinensis Baillon) water extract was added were investigated. The moisture contents of bellflower root Jeonggwa were 14.9-18.0%, where as that of lotus root Jeonggwa was 6.9-8.4%. The acidity of bellflower root Jeonggwa was 0.477-0.585% and that of lotus root Jeonggwa was 0.513-0.572%; values increasing levels of Omija extract. The lightness (L) and yellowness (b) values of bellflower root Jeonggwa decreased with increasing amounts of Omija extract, and the lightness (L), redness (a) and yellowness (b) values of lotus root Jeonggwa decreased with increasing Omija extract concentration (p<0.05). In mechanical tests with bellflower root Jeonggwa, the highest values of hardness and strength were seen at 2% (w/w) extract, of cohesiveness were seen with 4-8%, of springiness with 2-6%, of gumminess with 6-8%, and of brittleness with 4-6% (all p<0.01). In mechanical tests with lotus root Jeonggwa, the highest values of hardness and springiness were at 0 and 6% extract, respectively, whereas strength, gumminess and brittleness were at 6-8% Omija extract (all p<0.01). In sensory evaluation, the highest acceptability of bellflower root Jeonggwa was seen with 4% extract and that of lotus root Jeonggwa was seen with 2% extract.