• Title/Summary/Keyword: APEX1

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THE CANAL SYSTEM IN THE MESIOBUCCAL ROOT OF THE MAXILLARY FIRST MOLAR (상악 제1대구치 근심협측 치근의 근관계에 관한 연구)

  • Cho, Dong-Hyun;Choi, Ho-Young;Park, Sang-Hyuk;Choi, Gi-Woon
    • Restorative Dentistry and Endodontics
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    • v.28 no.3
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    • pp.232-240
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    • 2003
  • This study is to investigate the canal system in the mesiobuccal root of the maxillary first molar. 61 maxillary first molars were randomly selected. Serial transverse sections were made perpendicular to the long axis of the mesiobuccal root. Each section was placed in 3% sodium hypochlorite for 24 hours and rinsed in water and dried. The resected surface was stained with 2% methylene blue dye and examined with stereomicroscope. 1 Canal configuration analysis showed that 36.1% of the specimen classified as type I, 16.4% as type II , 37.7% as type III and 9.8% as type IV. 2. Type II canal was merged in one canal within 1 to 4mm of the apex. 40% of type II canal converged at 2mm of the apex. 3. Type IV canal was divided into two canal within 2 to 4mm of the apex. 66.6% of type IV canal branched off at 2mm of the apex. 4. None of the sections had more than two main root canal. 5. 48.4% of the sections in 3mm with two canals contained an isthmusand more than 70% with two canals has isthmus at 4 to 5mm sections. 63.9% of the mesiobuccal root of maxillary first molar had two canaland 76.5% of sections with two canals in 5 MM had an isthmus. Because of this complexity the clinician should always search for extra canal carefullyand root canal system, including an isthmus, should be cleaned and shaped completelyand obturated three dimensionally for successful endodontic treatment.

EXPERIMENTAL STUDY OF THE CENTER OF RESISTANCE OF A MAXILLARY CANINE USING LASER SPECKLE INTERFEROMETRY AND HOLOGRAPHIC INTERFEROMETRY (상악 견치의 저항 중심에 관한 Laser speckle interferometry와 holographic interferometry볼 이용한 실험적 연구)

  • Lee, Soo Ryong
    • The korean journal of orthodontics
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    • v.18 no.2
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    • pp.289-308
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    • 1988
  • The center of resistance is a important determining factor of tooth movement pattern. Laser speckle interferometry, recently developed for noninvasive measurement of small displacements (microns), was used to detect the center of resistance of a maxillary canine which has normal tooth axis and distal curved root in dry human skull. Laser holographic interferometry was used to verify the results of laser speckle interferometry The following result were obtained; 1. In measurement of the degree of rotation, center of resistance was localized when the traction line passed 4.4/18.0 level from alveola crest to root apex. 2. In measurement of the degree of tipping, center of resistance was localized when the traction line passed 4.6/18.0 level from alveola crest to root apex. 3. In holographic determination, the center of resistance was observed when the traction line passed between 3mm to 6mm level from alveola crest to root apex, therefore the results using laser speckle interferometry was coincided with holographic results.

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In vitro Propagation using Shoot Tip Culture of Curcuma longa L. (울금의 경정배양에 의한 기내번식)

  • 최성규
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.48 no.6
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    • pp.438-441
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    • 2003
  • The present study was carried out to assess the possibility of rapid multiplication of Curcuma longa Linne through in vitro culture of shoot-apex. The factor investigated was effect of various growth regulators on shoot-apex culture. The shoot-apex cultured of MS(Murashige and Skoog) medium developed into plantlet in 16 Weeks. M.S. medium containing NAA at 0.5 ppm and BA 5.0 ppm was found to be optimal for growth of in vitro plantlet

Basidiospore Development and Fine Structure of Entoloma squmiferrum (비늘외대버섯의 담자포자 발생과 미세구조)

  • Cho, Duck-Hyun;Lee, Sang-Rae;Kwon, Sun-Bang
    • Korean Journal of Plant Resources
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    • v.6 no.1
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    • pp.77-82
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    • 1993
  • Basidia of Entoloma squamiferrum are developed from hymenium layer of cartor-shaped parabasidium. Apex of basidium is flat or depressed in the center. Although four sterigmata are developed, only two sterigmata are symmetrically swollen to two spores im certain basidia. It means that two sterigmata among four sterigmata are imfertil. A spore is formed by inflation of the apex of the sterigma. The apex of the sterigma is swollen into a paillaform and then turned into a penisform. It is swollen from a clubform into a globefrom. Six spots of the surfaces of globose spore are depressed with hilum axes. Finally the spore is cuboid, and then it is released from hilum.

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A Study on the Age Determination with the Aid of Mandibular Molar Development (하악 구치 발육을 이용한 연령감정에 관한 연구)

  • Young-Don Hur;Jong-Mo Ahn;Chang-Lyuk Yoon
    • Journal of Oral Medicine and Pain
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    • v.19 no.2
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    • pp.221-231
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    • 1994
  • Age determination in children have been criticized because they rely on subjective estimations of tooth development, as seen in radiographs. This study was undertaken to obtain the objective estimation of developing teeth. The panoramic radiograph of 254 males and 254 females ranging from 6 to 14 years of age were studied. The structures measured were crown height, apex width and root length. The data weree statistically investigated with SPSS/PC + package. The results were as follows : 1. With the aid of a multiple regression model, a linear relationship between some of these distances and age was shown. 2. In th total material(6-14yr) and four-yr. intervals, linear equations are as follow : Boys : 6-14 age = 683 + 145.6 44RL + 126.6.45RL + 71.1 46DRL - 161.3 46DAW 6-10 age = 1202 + 72.6 46DRL + 100.2 44RL + 75.1 45RL 8-12 age = 3818 + 75.9 45RL - 190.9 44AW 10-14 age = 4151 + 58.6 45RL - 84.0 45AW - 130.6 44AW Girls : 6-14 age = 1587 + 104.9 45RL + 113.4 44RL - 233.1 46DAW + 81.4 47DRL - 255.9 46MAW 6-10 age = 1821 + 55.8 46DRL + 67.2 45RL - 184.2 46MAW + 56.3 44RL 8-12 age = 2435 + 68.2 45RLL + 71.3 44RL 10-14 age = 3485 + 49.9 47DRL - 51.3 45AW - 179.9 47DAW + 33.4 45RL + 39.4 44RL (DRL, length of distal root in molars. RL, root length in premolars. DAW, width of distal apex in molars. MAW, width of mesial apex in molars. AW, width of apex n molars)

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Surface Cover Effect for Reducing Nitrogen Load in Organic Farming Fields using APEX Model (APEX 모형을 이용한 유기농경지에서의 질소 부하량 저감을 위한 지표피복 효과)

  • So, Hyunchul;Jang, Taeil;Kim, Dong-Hyeon;Seol, Dong-Mun;Yoon, Kwangsik
    • Journal of The Korean Society of Agricultural Engineers
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    • v.60 no.5
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    • pp.55-67
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    • 2018
  • The objectives of this study were to monitor organic farming upland compared with conventional upland field and to evaluate nutrient loads reduction of surface cover effect with long-term historical climate data. APEX(Agricultural Policy Environmental eXtender) model was validated with experimental data and used for assessing surface cover scenarios for 30-year simulation periods. The validated values of RMSE(Root Mean Square Error), RMAE(Root Mean Absolute Error), $R^2$ and E(Nash-Sutcliffe efficiency) for runoff were 1.17-1.37 mm/day, 0.28-0.45 mm/day, 0.88-0.90 and 0.82-0.94 in two treatments, respectively. Those for water quality (nitrogen) were 0.05-0.16 kg/ha, 0.52-0.75 kg/ha, 0.67-0.72 and 0.32-0.70 in two treatments, respectively, and therefore the validated model showed good agreement with the observed runoff and nitrogen load for the study period. When decreasing the surface cover rate of organic farming field to 75%, 50%, 25%, and 0% (conventional field), average annual runoff increased by 7%, 15%, 23% and 31%, respectively. Under same condition of decreasing the surface cover rate, average annual nitrogen loads increased by 1.4 times, 1.7 times, 2.0 times, and 2.3 times compared with organic farming field, respectively. This study showed that it is possible to present an appropriate surface cover ratio to maintain conventional production and minimize nonpoint sources pollution for organic farming system, although long-term monitoring is needed to determine its effects on environmental concerns, crop competition, and other uncertainty.

A STUDY ON THE MICROLEAKAGE OF RETROFILLED TEETH WITH VARIOUS MATERIALS AND INSTRUMENTS FOR CAVITY PREPARATION (역행충전시 와동형성 기구 및 수복재에 따른 변연누출에 관한 연구)

  • Lee, Jae-Yong;Cho, In-Ho;Hong, Chan-Ui;Shin, Dong-Hoon
    • Restorative Dentistry and Endodontics
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    • v.18 no.1
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    • pp.187-196
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    • 1993
  • The purpose of this study was to evaluate the microleakage of retrofilled teeth with various materials [non-zinc Amalgam, IRM, Ketac-silver, CGP(cold-burnished, ultrafil)[and instruments for cavity preparation. Root apex were resected 2mm from apex horizontally and class I cavities were prepared in 2mm denpth, 1.5mm width and were filled with above mentioned materials. Root apex were resected 2mm from apex horizontally and class I cavities were prepared in 2mm depth, 1. 5mm width and were filled with above mentioned materials. 2% methylene blue dye solution was used for 4 days immersion and the linear leakage was measured with calipers and the volumetric leakage was determined with a spectrophotometer. The results were as follows : 1. Amalgam group showed the greatest amount of leakage and Ketac-silver group showed the least value. 2. By linear leakage test, the group retrofilled with Ketac-silver, or CGP showed better seal than the group of Amalgam or IRM. This was shown in both retrograde tip and Conventional method. 3. By volumetric leakage test, the group retrofilled with Ketac-silver showed significantly better seal than the group with IRM in retrograde tip method. 4. By volumetric leakage test, the group retrofilled with Ketac-silver showed significantly better seal than the group with Amalgam in the Conventional method.

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Morphological study on the tongue of Korean native goat (한국재래산양 혀에 관한 형태학적 연구)

  • Lee, Heungshik S.;Lee, In-se;Kang, Tae-cheon
    • Korean Journal of Veterinary Research
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    • v.36 no.2
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    • pp.255-264
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    • 1996
  • This studies were carried out to identify the characteristics of the tongue of Korean native goat(Capra hircus) by macroscopy, microscopy and scanning microscopy. Korean native goat had torus linguae, median lingual sulcus, lingual fossa and ventral median fissure but did not have glossoepiglottic fold and terminal sulcus in the tongue. The whole length of tongue was $11.51{\pm}0.76cm$. The length of tongue apex, tongue body, tongue root and the torus linguae were $2.62{\pm}0.28$, $7.39{\pm}0.27$, $1.56{\pm}0.26$ and $6.37{\pm}0.29cm$, respectively. The width of tongue apex, torus linguae and tongue root were $3.41{\pm}0.24$, $3.74{\pm}0.29$ and $3.68{\pm}0.11$, respectively. The thickness of tongue apex was $1.60{\pm}0.10$, and the height of torus linguae was $1.52{\pm}0.15cm$. Filiform papillae were present at the tongue apex and the tongue body rostral to torus linguae. Fungiform papillae were scattered from tongue apex to rostral portion of torus linguae, being in abundance at the tongue apex. Vallate papillae were showed at the lateral portion of torus linguae, while lentiform papillae were present at its central portion. Conical papillae were located between vallate and lentiform papillae. The numbers of filiform, fungiform, conical, vallate and lentiform papillae were $46,980{\pm}1070.98$, $446.8{\pm}36.97$, $818.4{\pm}43.99$, $34.8{\pm}2.77$, and $255.6{\pm}39.30$, respectively. The average numbers of taste bud were $8.3{\pm}2.04$ in a fungiform papilla and $247.3{\pm}37.44$ in a vallate papilla. The filiform papilla had secondary and tertiary papillae. The height of filiform papilla was about $150{\mu}m$ and the diameter was $100{\mu}m$. The diameters of fungiform papillae were 350 to $550{\mu}m$. The long and short diameters of maximum-sized lentiform papilla were 4000 and $3000{\mu}m$, respectively, while those of minimum-sized papilla were 700 and $600{\mu}m$, respectively. The height of conical papillae was 450 to $600{\mu}m$ and diameter was 250 to $450{\mu}m$. The vallate papilla was round or oval in shape and its diameter was 500 to $850{\mu}m$. It had well-developed papillary groove around itself. The modified conical papillae were not observed in the tongue of Korean native goat.

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A Study on a Morphological Identification of Pinelliae Tuber, Typhonii Flagelliformis Rhizoma and Arisaematis Rhizoma (반하(半夏), 수반하(水半夏) 및 천남성(天南星)의 형태(形態) 감별에 관한 연구)

  • Choi, Young-Seong;Kil, Ki-Jung;Lee, Young-Jong
    • The Korea Journal of Herbology
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    • v.22 no.2
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    • pp.103-108
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    • 2007
  • Objectives : A morphological classification among Pinelliae Tuber, Typhonii Flagelliformis Rhizoma and Arisaematis Rhizoma was made through microscopic observation. Method : The slice of the tested material made by paraffin section technique was colored with Safranine Malachite Green contrast methods, and then observed and photographed by olymphus-BHT. Result : 1. Pinelliae Tuber is like a ball with a $1{\sim}1.5cm$ diameter, with a concave apex and pockmarked root trace around. 2. Typhonii Flagelliformis Rhizoma is somewhat oval or like a cone, with a $4{\sim}8mm$ diameter, a $7{\sim}15mm$ height, a projected round apex, and a pin-pointed back. 3. Arisaematis Rhizoma is somewhat flat round with a $2{\sim}2.5cm$ diameter, a little than Pinelliae Tuber, and its apex has incomplete lobopodium and root trace. 4. Fundamental tissues of Pinelliae Tuber, Typhonii Flagelliformis Rhizoma, and Arisaematis Rhizoma have starch grains and mucilage cells, and their mucilage cells include the raphides of calcium oxalate. Conclusion : Internal forms of Pinelliae Tuber, Typhonii Flagelliformis Rhizoma, and Arisaematis Rhizoma are difficult to distinguish from one another, but Pinelliae Tuber and Arisaematis Rhizoma can be distinguished by their external forms and sizes, and Pinelliae Tuber and Typhonii Flagelliformis Rhizoma were distinguished by the forms of apex.

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Study on the Clonal Multiplication of Zingiber mioga ROSC. through in vitro Culture of Shoot Apex. I. Effects of Basal Media and Growth Regulators on Plant Regeneration and Growth of Plantlet (양하(襄荷)의 경정배양(莖頂培養)에 관(關)한 연구(硏究) I. 기본부지(基本部地) 및 생장조절물질(生長調節物質)이 식물체(植物體) 재분화(再分化)와 유묘(幼苗)의 생장(生長)에 미치는 영향(影響))

  • Choi, Seong-Kyu;Seo, Young-Nam
    • Korean Journal of Medicinal Crop Science
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    • v.1 no.1
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    • pp.38-42
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    • 1993
  • The present study was carried out to assess the possibility of rapid multiplication of Zingiber mioga ROSC. through in vitro culture of shoot-apex. The factor investigated was effect of various growth regulators on shoot-apex culture. The shoot-apex cultured of M. S. (Murashige and Skoog) medium developed into plantlet in 12 Weeks. M. S. medium containing NAA at 05ppm and BA 5.0ppm was found to be optimal for growth of in vitro plantlet.

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