• Imaging Science in Dentistry
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• 제41권1호
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• pp.17-21
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• 2011

Purpose : The purpose of this study was to examine the patient- and treatment-related etiologic factors of external root resorption. Materials and Methods : This study consisted of 163 patients who had completed orthodontic treatments and taken the pre- and post-treatment panoramic and lateral cephalometric radiographs. The length of tooth was measured from the tooth apex to the incisal edge or cusp tip on the panoramic radiograph. Overbite and overjet were measured from the pre- and post-treatment lateral cephalometric radiographs. The root resorption of each tooth and the factors of malocclusion were analyzed with an analysis of variance. A paired t test was performed to compare the mean amount of root resorption between male and female, between extraction and non-extraction cases, and between surgery and non-surgery groups. Correlation coefficients were measured to assess the relationship between the amount of root resorption and the age in which the orthodontic treatment started, the degree of changes in overbite and overjet, and the duration of treatment. Results : Maxillary central incisor was the most resorbed tooth, followed by the maxillary lateral incisor, the mandibular central incisor, and the mandibular lateral incisor. The history of tooth extraction was significantly associated with the root resorption. The duration of orthodontic treatment was positively correlated with the amount of root resorption. Conclusion : These findings show that orthodontic treatment should be carefully performed in patients who need the treatment for a long period and with a pre-treatment extraction of teeth.

• 동아시아식생활학회지
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• 제24권1호
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• pp.20-27
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• 2014

Our study is investigated the effects of Nelumbo nucifera root extract on HT-29 colon cancer cells. The anti-proliferative effect of 70% ethanol extract from Nelumbo nucifera root on HT-29 colon cancer cells was identified based on cell viability, Hoechst 33342 nuclear staining, apoptosis analysis, Western blotting and RT-PCR analyses. In our study, Nelumbo nucifera root extract inhibited the growth of HT-29 colon cancer cells in a dose-dependent manner. Concomitant activation of the mitochondria-dependent apoptotic pathway of HT-29 colon cancer cells by Nelumbo nucifera root extract occurred via modulation of Bax and Bcl-2 expressions, which activated cleavage of caspases-3 and -9. The findings of this study indicate that Nelumbo nucifera root extract induces apoptosis in HT-29 colon cancer cells, and this phenomenon is occurs via the death receptor-mediated and mitochondria-mediated apoptotic pathways.

• Journal of Ginseng Research
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• 제16권1호
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• pp.31-36
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• 1992

The ultrastructural changes and differentiation mechanism of chromoplasts and leucoplasts from Proplastids in root tip cells of Panax ginseng seedlings were studied with transmission electron microscope. Initial cells have so many proplastids with a few osmiophilic droplets and a lot of mitochon dria at early stage of germination, therefore electron density of cytoplasm is generally higher than that of the other cells just like periblem, plerome and root cap. Proplastids are observed in the initial cells, but only leucoplasts appeared in the central root cap cells. Because root cap cells are derived ultimately from initial cells, the cell organelles in the root cap cells are directly related by those of initial cells. This result postulates that leucoplast is diferentiated from proplastid, and this is the same with other's concepts. On the contrary, the precise observations of chromoplast with crystalline inclusions in the peripheral root cap cells can conclude the direct pathway of chromoplast development from proplastid. Because of the differences of these result from those of other experiments, new scheme of plastid development, direct differentiation of chromoplast from proplastid, can be postulated. And this is the originality of this research on the differentiation of plastids.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.103-103
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• 2017

Vigorous root growth at the seedling stage in dry direct-seeded conditions is considered as a critical trait because it is involved in seedling emergence, early vegetative vigour, nutrient uptake as well as drought tolerance. In this study, we performed QTL mapping using the recombinant inbred lines obtained from the cross between Tongil-type Dasan and temperate japonica TR22183 (DT-RILs) to identify QTL underlying early root development. TR22183, which was previously reported to have high nitrogen utility and cold tolerance, showed vigorous root growth at the seedling stage in semi-drought conditions. Root length, fresh weight and dry weight of TR22183 were significantly higher than in Dasan. By QTL analysis with genotyping-by-sequencing method, we identified two QTLs for root fresh weight (RFW) in chromosome 7 and root dry weight (RDW) in chromosome 8, explaining phenotypic variances of 13.5% and 10.6%, respectively. These QTLs would be used to develop rice varieties adapted to direct-seeded cultivating system.

• The Plant Pathology Journal
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• 제21권1호
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• pp.73-76
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• 2005

Oriental melon, Cucumis melo L. cv. Geumssaragieuncheon, grafted on Shintozoa (Cucurbit maxima ${\times}$ Cu. moschata) was planted in a greenhouse infested with Meloidogyne arenaria and root galls were examined five months after planting. A gram of root gall was volumed at ca. 10 cm3 and contained in an average of 363 females (170 developing and 193 matured females), 2,120 secondstage juveniles (J2), and 13,074 eggs. In addition, there was 56 J2 per $cm^3$ soil around the infested plant. An oriental melon had an average of 134.6 g of root gall (70% of total root weight) per 0.72 $m^2$ area. In a conservative estimation, an oriental melon plant could accommodate ca. 1.2 ${\times}$ $10^7$ eggs and J2 per 0.72 $m^2$. The eggs contained in root tissues could be an important inoculum source to the next crop and the fate of these eggs are well worth further investigation.

• 식물조직배양학회지
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• 제22권3호
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• pp.169-173
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• 1995

근관 표피세포(border cell)는 근관(root cap)의 최외각 세포층에서 분화된 단일세포로서, 물리적인 힘을 가하면 예를 들어 근관의 근관 표피세포를 물로 씻어내면, 20∼25시간 이후에는 새로운 층의 근관 표피세포가 근관에 형성된다. 이 새로운 층의 완두 근관 표피세포가 형성되는 동안 근관 표피세포가 제거된 근관에서는 새로운 유전자 발현이 일어나고 있음이 mRNA differential display로 확인되었다. 즉, 이들 근관에서 새롭게 발현되는 유전자들의 일부는 근관 표피 세포의 분화에 관련되어 있다고 볼 수 있다. 또한, 단일 세포로 분화된 근관 표피세포에서는 독특한 유전자 발현이 일어나고 있음이 mRNA differential display로 확인되었다. 이 결과로 알 수 있는 것은 근관 표피세포는 다른 조직(잎, 줄기, 뿌리와 근관 표피세포가 제거된 근관)과는 다른 독특한 기능을 가졌다는 것이다.

• KSBB Journal
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• 제6권1호
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• pp.27-33
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• 1991

감자(Solannum tuberosum) 괴경에 A. rhizogenes를 접종하여 암소에서 배양한 결과 2-4주 후에 hairy root가 유도되었다. 유도된 hairy root는 opine 분석을 통해 agropine과 manopine이 검출되어 형질이 전환되었음을 확인하였으며, 발생이 진행됨에 따라 단백질은 전차 감소 되었고, 전분은 점차 증가함을 보였으며, GS.II의 활성 또한 발생단계에 따라 증가함을 보였다. $Ca^{2+}$ channel blocker 인 verapamil 처리구에서는 약 60% 정도 GS II의 활성이 감소 되었으며, calmodulin inhibitor인 chloropromazine 처리구에서는 GS II의 활성에 별 영향을 미치지 않았다. 한편 peroxidase 활성은 3주 동안 배양한 callus에서 가장 높았으며, peroxidase 양상은 hairy root에서는 pI 5.4, 5.9의 band가 나타난 반면, 3주 동안 배양한 callus에서는 pI 6.4, 7.1, 7.4의 새롱룬 band를 얻었다.

• Restorative Dentistry and Endodontics
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• 제43권1호
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• pp.10.1-10.8
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• 2018

Objectives: To examine the surface topography of intact WaveOne (WO; Dentsply Sirona Endodontics) and WaveOne Gold (WOG; Dentsply Sirona Endodontics) nickel-titanium rotary files and to evaluate the presence of alterations to the surface topography after root canal preparations of severely curved root canals in molar teeth. Materials and Methods: Forty-eight severely curved canals of extracted molar teeth were divided into 2 groups (n = 24/each group). In group 1, the canals were prepared using WO and in group 2, the canals were prepared using WOG files. After the preparation of 3 root canals, instruments were subjected to atomic force microscopy analysis. Average roughness and root mean square values were chosen to investigate the surface features of endodontic files. The data was analyzed using one-way analysis of variance and post hoc Tamhane's tests at 5% significant level. Results: The surface roughness values of WO and WOG files significantly changed after use in root canals (p < 0.05). The used WOG files exhibited higher surface roughness change when compared with the used WO files (p < 0.05). Conclusions: Using WO and WOG Primary files in 3 root canals affected the surface topography of the files. After being used in root canals, the WOG files showed a higher level of surface porosity value than the WO files.

• 한국초지조사료학회지
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• 제39권4호
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• pp.298-302
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• 2019

Acidic soil significantly reduces crop productivity mainly due to aluminum (Al) toxicity. Alfalfa (Medicago sativa L.) roots were exposed to aluminum stress (Al₃⁺) in calcium chloride (CaCl₂) solution (pH4.5) and root growth, physiological and antioxidant enzyme responses were investigated. The root growth (length) was significantly inhibited after 48 h of aluminum stress imposition. Histochemical staining with hematoxylin indicated significant accumulation of aluminum in Al stress-treated root tissues. Histochemical assay were also performed to detect superoxide anion, hydrogen peroxide and lipid peroxidation, which were found to be more in root tissues treated with higher aluminum concentrations. The enzymatic activity of CAT, POD and GR in root tissues was slightly increased after Al stress treatment. The result suggests that Al stress alters root growth in alfalfa and induces reactive oxygen species (ROS) production, and demonstrates that antioxidant enzymes involved in detoxification of Al-mediated oxidative stress.

• The Plant Pathology Journal
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• 제29권1호
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• pp.59-66
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• 2013

Colonization studies previously performed with a green-fluorescent-protein, GFP, labeled derivative of Bacillus amyloliquefaciens FZB42 revealed that the bacterium behaved different in colonizing surfaces of plant roots of different species (Fan et al., 2012). In order to extend these studies and to elucidate which genes are crucial for root colonization, we applied targeted mutant strains to Arabidopsis seedlings. The fates of root colonization in mutant strains impaired in synthesis of alternative sigma factors, non-ribosomal synthesis of lipopeptides and polyketides, biofilm formation, swarming motility, and plant growth promoting activity were analyzed by confocal laser scanning microscopy. Whilst the wild-type strain heavily colonized surfaces of root tips and lateral roots, the mutant strains were impaired in their ability to colonize root tips and most of them were unable to colonize lateral roots. Ability to colonize plant roots is not only dependent on the ability to form biofilms or swarming motility. Six mutants, deficient in abrB-, sigH-, sigD-, nrfA-, yusV and RBAM017410, but not affected in biofilm formation, displayed significantly reduced root colonization. The nrfA- and yusV-mutant strains colonized border cells and, partly, root surfaces but did not colonize root tips or lateral roots.