• The Journal of Korean Academy of Prosthodontics
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• v.36 no.2
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• pp.293-301
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• 1998

The purpose of this study was to investigate the effects of load on root that was applied to edentulous area in three simulated situation, in each case the guiding planes of abutment were right vertical, 95 degrees, or 100 degrees to residual ridge. The 2-dimensional finite element method was used and the finite element model was prepared as fellows. Right mandibular 1st and 2nd molar was lost and the 2nd premolar with distal rest was used as primary abutment which had three different degrees of guiding plane. Then 150N of compressive force was applied to central fossae of the 1st and 2nd molars and von Mises stress and displacement was measured. The results were as follows; 1. Irrespective of slopes of guiding planes, the stress was concentrated on mesial side of root apex and distal side of coronal portion of root, in particular on junction with distal alveolar bone. As slopes of guiding planes were increased. stress on root and compact bone surrounding abutment was increased but no considerable effect was seen on compact bone of residual ridge. 2. Distal side of coronal portion of root limited by periodontal ligament was displaced distally and mesial side of apical portion was mesially. With slope of guiding plane increasing, the pattern of displacement was similar with one another but the quantity was increased. 3. Both abutment & alveolar bone were displaced downward and root of abutment, especially distal side of coronal portion, was displaced severely. As the guiding plane was tiffed more mesially over $90^{\circ}$, the degree of displacement was also increased.

• Molecules and Cells
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• v.41 no.10
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• pp.923-932
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• 2018

Ethylene regulates numerous aspects of plant growth and development. Multiple external and internal factors coordinate ethylene production in plant tissues. Transcriptional and post-translational regulations of ACC synthases (ACSs), which are key enzymes mediating a rate-limiting step in ethylene biosynthesis have been well characterized. However, the regulation and physiological roles of ACC oxidases (ACOs) that catalyze the final step of ethylene biosynthesis are largely unknown in Arabidopsis. Here, we show that Arabidopsis ACO1 exhibits a tissue-specific expression pattern that is regulated by multiple signals, and plays roles in the lateral root development in Arabidopsis. Histochemical analysis of the ACO1 promoter indicated that ACO1 expression was largely modulated by light and plant hormones in a tissue-specific manner. We demonstrated that point mutations in two E-box motifs on the ACO1 promoter reduce the light-regulated expression patterns of ACO1. The aco1-1 mutant showed reduced ethylene production in root tips compared to wild-type. In addition, aco1-1 displayed altered lateral root formation. Our results suggest that Arabidopsis ACO1 integrates various signals into the ethylene biosynthesis that is required for ACO1's intrinsic roles in root physiology.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.1
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• pp.123-130
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• 2018

In the root fracture, pulp necrosis tends to involve only the coronal fragment, while the pulp in the apical fragment remains vital. The prognosis of endodontic treatment of the apical fragment is poor due to the possibility of overfilling of the space between the fragments and difficulty in removing necrotic tissue. In the present cases, endodontic treatment of the apical fragment of root fracture was performed. However, in reendodontic treatment, resistance was felt at the fracture site and access to the root canal in the apical fragment was difficult. Therefore, the calcium hydroxide was periodically exchanged only in the coronal fragment without further treatment in the apical fragment and the canal of the coronal fragment was finally filled with Gutta-percha. Regular observation revealed no radiologic complications in the apical fragment. In some cases, we can observe good healing pattern such as absorption of calcium hydroxide and pulp canal obliteration of apical fragment in the long term.

• Restorative Dentistry and Endodontics
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• v.24 no.3
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• pp.495-502
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• 1999

Recently root caries is reported as an increasing oral disease Many researchers studied in vivo and in vitro enamel lesions but due to its peculiar structure and different chemical composition compared to the enamel, little effort has been made to root caries study. The purpose of this study is to compare and to evaluate the effect of pH on the progression of artificial root caries lesion. Under the constant degree of saturation, the specimens were divided into 4 groups(pH 4.3, 5.0, 5.5, 6.0). Each group was immersed in acid buffer solution for 1, 3, 5, 7 days and examined using the polarizing microscope. The results were as follows: 1. The body of the lesion in the dentin showed higher degree of positive birefringence compared to sound dentin. 2. The rate of progression of the lesion slowed as the pH increased. 3. In all groups, the lesion progressed rapidly at the initiation or the experiment but increased gradually as time elapsed. In conclusion, the study shows that the pH in the acid buffer solution influenced the rate of progression of the lesion in artificial root caries. Compared to the previous enamel study, the initial pattern of the lesion progressed rapidly and as time elapsed increased gradually.

• KSBB Journal
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• v.13 no.2
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• pp.155-161
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• 1998

The hairy roots of Crotalaria sessiliflora were induced from the tissue segments infected with Agrobacterium rhizogenes ATCC 15834. The induced hairy roots were subjected to paper electrophoresis fro the detection of opine-positive clones which were considered to have been transformed. Mannopine and agropine were presented in hairy root clones while mannopine was presented in two hairy root clones. Eight hairy root clones were selected and cultured in MS, B5 and WP media. Each of hairy root clones was showed a difference in branch pattern and growth rate. The best culture medium and culture conditions of hairy roots were in $\frac{1}{2}$MS(3% sucrose, pH 5.7) liquid medium at 25$^\circ C$, 70 rpm under dark, the growth rate in $\frac{1}{2}$MS liquid medium was increased with 210-fold more than that of inoculated hairy roots and with 2-fold more than that in MS liquid medium. Also, the adequate condition for hairy root growth was such that concentration of KH$_2PO$_4 was 1.25mM and the ratio of NH${_4}{^+}$ : NO${_3}{^-}$ was 1 to 3 in MS medium. The presence of pyrrolizidine alkaloids, monocrotaline, in the hairy roots was detected by TLC.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.3
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• pp.303-316
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• 1993

The purpose of this study was to analysis the stress distribution induced by three unit PFM bridges and various cantilever bridges replacing maxillary latersal incisor. The simplified two-dimensional photoelastic models used for this study was contructed in the folio- wing way. CR/R ratio was designed to be 1 : 1, 1 : 1.25 and 1 : 1.5. The pontics of cantilever bridge supported by maxillary canines consisted of wrap-around type, rest-extension type, and simple type. 3-unit PFM bridge was constructed with traditional method. 1kg vertical static load was applied on the center of the incisal edge of the pontic. The stress pattern was examined and recorded by photography. The results obtained were as follows ; 1. The magnitude of stress on the abutment root apex area of a traditional 3-unit bridge was the lowest. 2. The model of cantilevered pontic with a rest showed the relatively well distributed stress around the abutment tooth. The model with simple pontic generated the greatest stress concentration in the supporting structure of the abutment tooth. 3. As the height of bone level reduced, the rotational and vertical force increased around the abutment tooth. 4. The stress concentration of the 3-unit bridges occured on the root apex and stress concentration of the cantilever briage occured on the root apex and cervix area, 5. In the case of the cantilever bridge, stress concentrated distally on the root apex area of the abutment tooth and additional stress was observed mesially on the upper part of the root. Especially in the case of the simple pontic, was phenomenon was more apparent than the others. 6. Force applied to cantilevered pontic was transmitted to the adjacent central incisor through the contact surface. Stress was markedly observed on the mesial cervix area in the case of simple pontic and on the root apex area in the case of wrap-around type and rest-extension type.

• Applied Microscopy
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• v.28 no.4
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• pp.435-446
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• 1998

It is suggested that Urechis unicinctus is a filler feeder as like many tide and watery invertebrates which filtrate food materials by ciliary movement. However, the structure of the filter is not yet known in U. unicinctus, nor the filtering mechanism is not well understood. This study reveals ciliated epithelial cells in the foregut and the features of the cilia are good accord with that of known filtrating apparatus of other tide animals. This may implies that the foregut is in function of filtration and the food materials are filtrated by the ciliary movement. With the observation of the filtrating apparatus in the foregut, the intestine of U. unicinctus can be functionally compartmented into 3 parts. These are already known midgut and hindgut in function of digestion and respiration respectively, and the foregut in function of filtrating apparatus for foods. The filtrating apparatus of U. unicinctus is composed of the pseudostratified columnar epithelial cells with numerous cilia. The cilia are well differentiated kinocilia with the typical microtubule pattern, kinetosome and cilia roots. There are two kinds of striated cilia roots, the main root and the accessory root. The main root is extended perpendicularly from the cell surface to basement membrane and the short accessory root is branched with an acute angle of about $80^{\circ}$ from the main root at level of basal plate of the kinetosome. The spacial approaches of the main root with the large fused form of mitochondria is one of the characteristic features which might be in structural consideration an intimate association between energy source and energy mass consuming cell organelles.

• Journal of Ginseng Research
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• v.20 no.3
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• pp.291-298
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• 1996

Free amino acid (FAA) compositions in the central part (pith-xylem : P-X) and the outer part (phloem-cortex : P-C) of root were investigated for P ginseng (P.g), p. quinque-folium (P.q) an, B P nutoginsen (P.n) by an amino acid analyzer. Total free amlno acids content (TFAA) was highest in p.맥 and lowest in p.n. The TFAA of P-Xs were higher than those of P-Cs in these Panax species except p.n. The higher the TFAA in P-X, the higher the ratio of TFAA in P-X to that in P-C. Seven- teen free amino acids and ammonia were identified, and four unknown peaks appeared before the usual amino acids eluted. The total aspartic acid equivalent of these unknown peaks was corresponded to 77% of known TFAA in P-C of p.n, 17% in P. n, and 7% in p.q. The pattern of unknown peaks of p.g was different from p.q and similar to P.n. In all samples six major amino acids and ammonia accounted for 90~95% of TFAA. Arginine was comprised from 29% (P.n) to 43% (P.g) by amole as amino acid and from 50 to 71% by amole as nitrogen (N amole) in TFAA. Ammonia was the second abundant one by amole and the third by Npmole. Histidine was the second by Npmole. Praline was one of major FAA in p.q. Pattern similarity of FAA composition (excluding Arg and Am) by simple correlation was closer between P-C of p.g and P-X of p.q than between both P-Xs and quite different between the P-X of p.g and that of p.n. The pattern similarities of major FAA percent abundance excluding Arg and Am were significant only between P-X and P-C of the same species. Arginine content (amole) had positive correlation (r=0.859, p=0.05) with Arg/Am among species. Ammonia content was higher than arginine in p.n. Tryptophan content was greatest in p.n among species and higher than lysine only in p.n. The ratios of TFAA to N(W/W) were in the range of 3.89~4.14 for TFAA and 3.61~3.92 for TFAA plus ammonia.

• Plant Biotechnology Reports
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• v.3 no.1
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• pp.75-85
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• 2009

We report here a first evaluation of chilling-responsive gene regulation in the sweetpotato. The growth of sweetpotato plants was severely retarded at $12^{\circ}C$; the lengths of the leaf, petiole, and root were markedly reduced and microscopic observation revealed that the elongation growth of the epidermal cells in each of these organs was significantly reduced. We examined the transcriptional regulation of three sweetpotato expansin genes (IbEXP1, IbEXP2 and IbEXPL1) in response to various chilling temperatures (12, 16, 22, and $28^{\circ}C$). In the leaf and petiole, the highest transcript levels were those of IbEXP1 at $28^{\circ}C$, whereas IbEXPL1 transcript levels were highest in the root. IbEXP1 mRNA levels in the $12^{\circ}C-treated$ petiole showed a fluctuating pattern (transient decrease-recovery-stable decrease) for 48 h. In the leaf and petiole, IbEXP1 and IbEXPL1 exhibited a similar response to chilling in that their mRNA levels decreased at $22^{\circ}C$, increased at $16^{\circ}C$, and decreased dramatically at $12^{\circ}C$. In contrast, mRNA levels of IbEXP2 in the leaf fell gradually as the temperature fell from 28 to $12^{\circ}C$, while they remained unaltered in the petiole. In the root, mRNA levels of IbEXPL1 and IbEXP1 reached maximum levels at $16^{\circ}C$, and decreased significantly at $12^{\circ}C$. These data demonstrated that expression of these three expansin genes was ultimately down-regulated at $12^{\circ}C$; however, transcriptional regulation of each expansin gene exhibited its own distinctive pattern in response to various chilling temperatures.

• Archives of Plastic Surgery
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• v.45 no.5
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• pp.411-417
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• 2018

Background Accessory auricles (AAs) are common congenital anomalies. We present a new classification according to location and shape, and propose a system for coding the classifications. Methods This study was conducted by reviewing the records of 502 patients who underwent surgery for AA. AAs were classified into three anatomical types: intraauricular, preauricular, and buccal. Intraauricular AAs were divided into three subtypes: intracrural, intratragal, and intralobal. Preauricular AAs were divided into five subtypes: precrural, superior pretragal, middle pretragal, inferior pretragal, and prelobal. Buccal AAs were divided into two subtypes: anterior buccal and posterior buccal. AAs were also classified according to their protrusion pattern above the surrounding surface: pedunculated, sessile, areolar, remnant, and depressed. Pedunculated and sessile AAs were subclassified as spherical, ovoid, lobed, and nodular, according to their body shape. Cartilage root presence and family history of AA were reviewed. A coding system for these classifications was also proposed. Results The total number of AAs in the 502 patients was 1,003. Among the locations, the superior pretragal subtype (27.6%) was the most common. Among the protrusion patterns and shapes, pedunculated ovoid AAs were the most common in the preauricular (27.8%) and buccal areas (28.0%), and sessile lobed AAs were the most common in the intraauricular area (48.7%). The proportion of AAs with a cartilage root was 78.4%, and 11% of patients had a family history. The most common type of preauricular AA was the superior pretragal pedunculated ovoid AA (13.2%) with a cartilage root. Conclusions This new system will serve as a guideline for classifying and coding AAs.