• Restorative Dentistry and Endodontics
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• 제10권1호
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• pp.115-126
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• 1984

The purpose of this study was to determine the incidence and the degree of interappointment pain and post obturation pain associated with the pretreated clinical factors or conditions, and to examine the correlation between the success or failure and the pretreated clinical factors or conditions and postoperative pain. The author experienced the conventional root canal therapy in one hundred fifty-one teeth after recording the following clinical factors or conditions - sex, age, pulp vitality status, presence or absence of periapical rarefaction, single or multirooted teeth, pretreatment pain, and investigated the pain during and after treatment for seven days. After six months all the cases were re-evaluated through the clinical sign, symptom, and the recalled radiograph. The following results were obtained; 1. Of the 151 teeth (73.5%) had no interappointment pain, 31 teeth (20.5%) slight pain; and 9 teeth (6.0%) moderate to severe pain. 2. The presence of the pretreatment pain significantly increased the incidence and degree of interappointment, and there were no significant relationship between interappointment pain and other clinical factors or conditions. 3. Of the 151 teeth, 142 teeth (4.0%) experienced no post obturation pain, 3 teeth (2.0%) slight pain, 6 teeth (4.0%) moderate to severe pain. 4. There were no statistical correlation between postobturation pain and any of the clinical factor or conditions. 5. 141 teeth (3.4%) of 151 teeth were evaluated as success in this study, and success rate was decreased significantly in the cases of periapical rarefaction before treatment and postobturation pain. But there were no significant relationship between success or failure and other clinical factors or conditions.

• Restorative Dentistry and Endodontics
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• 제37권1호
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• pp.29-33
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• 2012

Objectives: The purpose of this study was to evaluate the microleakage of 4 temporary materials in teeth with Class II-type endodontic access preparations by using a glucose penetration model. Materials and Methods: Glucose reaction test was performed to rule out the presence of any reaction between glucose and temporary material. Class II-type endodontic access preparations were made in extracted human premolars with a single root (n = 10). Each experimental group was restored with Caviton (GC), Spacer (Vericom), IRM (Dentsply-Caulk), or Fuji II(GC). Microleakage of four materials used as temporary restorative materials was evaluated by using a glucose penetration model. Data were analyzed by the one-way analysis of variance followed by a multiplecomparison Tukey test. The interface between materials and tooth were examined under a scanning electron microscope (SEM). Results: There was no significant reaction between glucose and temporary materials used in this study. Microleakage was significantly lower for Caviton and Spacer than for Fuji II and IRM. SEM observation showed more intimate adaptation of tooth-restoration interfaces in Caviton and Spacer than in IRM and Fuji II. Conclusions: Compared to IRM and Fuji II, Caviton and Spacer can be considered better temporary sealing materials in Class II-type endodontic access cavities.

• 한국융합학회논문지
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• 제8권7호
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• pp.123-129
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• 2017

본 연구는 모발 수질의 형태적, 미세구조적 특성을 주사전자현미경과 투과전자현미경을 사용하여 관찰하였다. 수질은 모발의 중앙부위에 존재하며 모발의 장축을 따라 기부에서부터 정단부위까지 불연속적으로 존재한다. 또한, 수질은 일정한 모양으로 존재하지 않고 매우 불규칙한 모양을 하고 있다. 한 개의 모발에서 연속되는 수질의 두께는 매우 다양하게 나타났다. 모발의 가로 절단면에서 수질의 두께는 최고 $21{\mu}m$로 측정되었고 세로 절단면에서는 최고 $27{\mu}m$로 측정되었다. 수질은 모발 직경의 1/3-1/4을 차지하고 있다. 수질은 각화된 수질형성세포의 거대원섬유들이 분리되면서 빈 공간을 형성하고 있다. 수질에 형성된 빈공간은 최고 $6.5{\mu}m$의 직경을 가지고 있으며 공기로 채워져 있다.

• 구강회복응용과학지
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• 제29권4호
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• pp.399-406
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• 2013

자연치아와 연결한 임플란트 수복물에서 종종 자연치아의 압하가 보고되곤 하지만 임플란트에 둘러싸인 자연치아의 압하에 대한 보고는 매우 드물다. 56세의 여성을 하악 우측 제1소구치는 임플란트로, 제 2소구치 치근은 포스트 수복 후 지르코니아로 각각 수복했다. 제 1대구치와 제 2대구치는 이미 임플란트로 수복되어 있었다. 기능 4개월 후 제 2소구치의 압하로 인한 대합치와의 간격이 분명히 관찰되었으나 불편감을 비롯한 이상증상은 없었다. 예후에 대한 자세한 설명 후 별다른 조치 없이 경과 관찰을 시작하였다. 3개월 후 치근단 방사선 사진상에서 원위치로의 치아 회복 시작이 관찰되었으며 다시 11개월이 경과한 후 치아의 추가 정출로 교합의 완전한 회복이 이루어졌다. 압하를 인지한지 2년 3개월째 관찰 중이다. 임플란트에 둘러싸인 자연치가 압하되고 저절로 회복되는 과정의 관찰을 통해 압하가 생기는 원인과 저절로 회복된 기전을 추정할 수 있었다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권10호
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• pp.461-466
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• 2006

In the present work, we investigated the photodissolution and photodiffusion effect on the interface of Ag/chalcogenide $As_{40}Ge_{10}Se_{15}S_{35}$ thin film by measuring the absorption coefficient, the optical density, the resistance change of Ag layer. It was found that the photodissolutioniphotodiffution ratio depends on the magnitude of photon energy absorbed in the chalcogenide thin film and the depth of photodiffution was proportional to the square root of the exposed time. Also, we have investigated the holographic grating formation with P-polarization states on chalcogenide $As_{40}Ge_{10}Se_{15}S_{35}$ thin film and $As_{40}Ge_{10}Se_{15}S_{35}/Ag$ double layer structure thin film. Holographic gratings have been formed using He-Ne laser (632.8 nm) which have a smaller energy than the optical energy gap, $E_g\;_{opt}$ of the film, i. e., an exposure of sub-bandgap light $(h{\upsilon} under P-polarization. As the results, we found that the diffraction efficiency on $As_{40}Ge_{10}Se_{15}S_{35}/Ag$ double layer structure thin film was more higher than that on single $As_{40}Ge_{10}Se_{15}S_{35}$ thin film. Also, we obtained that the maximum diffraction efficiency was 0.27 %, 1,000 sec on $As_{40}Ge_{10}Se_{15}S_{35}\;(1{\mu}m)/Ag$ (10 nm) double layer structure thin film by (P: P) polarized recording beam. It will offer lots of information for the photodoping mechanism and the analyses of chalcogenide thin films.

• 한국응용곤충학회지
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• 제15권2호
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• pp.57-60
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• 1976

새로운 침투성 살균제 EL-291 (5-Methyl-1,2,4-tri-azolo(3, 4-b) benzothiazole, $75\%$ 수화제)의 벼 도열병 방제효과를 구명코저 온실검정과 포장시험을 실시하였다. EL-291은 병원균 접종후 살포보다 접종전 살포시 효과가 뚜렷하여 현저한 예방효과를 나타냈으나 가스가민, 벤레이트 상반된 반응을 나타내어 치료제로서 작용했다. 잎 도열병방제효과는 EL-291과 가스가민, 벤레이트간에 차이가 없었으나 이들 약제의 2회 살포에 비해 EL-291은 근침처리 또는 1회 살포한 것이므로 사용이 간편하고 경제적이라 할 수 있겠다. 이삭도열병에서도 1회 살포한 EL-291이 2회 살포한 가스가민, 벤레이트보다 월등히 효과가 좋았으며 수량도 EL-291 처리구가 더 많았다.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1994년도 춘계학술대회논문집
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• pp.49-51
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• 1994

The aims of this study were first to determine the influence of vibration displacement amplitude $(200{\mu}m, 300{\mu}m peak-to-peak)$ at selected frequencies (40-200Hz) on a commonly observed but often undesired motor response elicited bylocal vibratory stimulation, the Tonic Vibration Reflex (TVR). Second, to determine the degree of synchronization of motor unit (MU) activity with vibratory stimuli. Vibration was applied to the distal tendons of the hand flexor muscles. Changes in root- mean-square electromyographic (EMG) activity of the finger and wrist flexor muscles were analyzed both as a function of their initial contraction level (0%, 10%, 20% of the maximal voluntarycontraction: MVC) and as a function of the vibration parameters. The results indicate that the TVR increased with the initial muscle contraction up to 10% MVC: The TVR increased with vibration frequency up to 100-150 Hz and decreases beyond; A significant increase of the TVR with vibration displacement amplitude was observed only for the wrist flexor muscle; MU synchronization at vibration frequency (VF) was found more often in the low frequency range $(f{\leq}100 Hz)$ and tended todecrease beyond; In the high frequency range $(f{\geq}120 Hz)$, MU activity at subharmonic frequency was predominant; The "cut-off" frequency of the synchronization with VF was neither affected by the vibration displacement amplitude nor initial muscle contraction level. The surface EMG turned out to be a useful means to analyze MU synchronization since it is noninvasive, and it can be easily used for analysis of different muscle contraction levels, while single MU technique might have some difficulties at high muscle contraction levels. Furthermore, these results indicate that high frequencyvibration (f>150 Hz) tends to induce less muscle/tendon stress and MU synchronization. Such remarks are of importance for the design of hand-held vibrating tools.ing tools.

• 치과방사선
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• 제28권1호
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• pp.87-109
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• 1998

The present study was designed to elucidate the effects of the Co-60 γ irradiation and/or calcium­deficient diet on the dentin and cementum formation of rat molar. The pregnant three-week old Sprague­Dawley rats were used for the study. The experimental group was divided into two groups, irradiation/normal diet group and irradiation/calcium-deficient diet group. The control group was non­irradiation/normal diet group. The abdomen of the rats at the 19th day of pregnancy were irradiated with single absorbed dose of 350cGy. The rat pups were sacrificed on the 14th day after delivery and the maxillae including molar tooth germ were taken. The specimens including the 1st molar tooth germ were prepared to make tissue sections for light and transmission electron microscopy. Some of tissue sections for light microscopy were stained immunohistochemically with anti-fibronectin antibody. The results were as follows; 1. The Hertwig's epithelial root sheath cells, which are related to the differentiation of the tooth-forming cells, showed irregular cellular arrangement, decrease of intercellular junctional complex, and decreased immunoreactivity to the fibronectin after irradiation. These were more severe in the irradiation/calcium-deficient diet group. 2. The cementoblasts at the cementum-forming area showed chromatin clumpings after irradiation. The immu noreactivity to the fibronectin was weaken after irradiation, especially irradiation/calcium-deficient diet group. 3. The odontoblasts at the dentin-forming area showed increase of lysosomes in the cytoplasm and destruction of intercellular junctional complex. The irradiation/calcium-deficient diet group showed decrease of number and density of the electron dense particles and a large number of vacuoles scattered in the dentin matrix. The immunoreactivity was weaken.

• Annals of Clinical Neurophysiology
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• 제8권2호
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• pp.163-170
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• 2006

Backgrounds: MEG can measure the task-specific neurophysiologic activity with good spatial and time resolution. Language lateralization using noninvasive method has been a subject of interest in resective brain surgery. We purposed to develop a paradigm for language lateralization using MEG and validate its feasibility. Methods: Magnetic fields were obtained in 12 neurosurgical candidates and one volunteer for language tasks, with a 306 channel whole head MEG. Language tasks were word listening, reading and picture naming. We tested two word listening paradigms: semantic decision of meaning of abstract nouns, and recognition of repeated words. The subjects were instructed to silently name or read, and respond with pushing button or not. We decided language dominance according to the number of acceptable equivalent current dipoles (ECD) modeled by sequential single dipole, and the mean magnetic field strength by root mean square value, in each hemisphere. We collected clinical data including Wada test. Results: Magnetic fields evoked by word listening were generally distributed in bilateral temporoparietal areas with variable hemispheric dominance. Language tasks using visual stimuli frequently evoked magnetic field in posterior midline area, which made laterality decision difficult. Response during task resulted in more artifacts and different results depending on responding hand. Laterality decision with mean magnetic field strength was more concordant with Wada than the method with ECD number of each hemisphere. Conclusions: Word listening task without hand response is the most feasible paradigm for language lateralization using MEG. Mean magnetic field strength in each hemisphere is a proper index for hemispheric dominance.

• Journal of Ginseng Research
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• 제18권3호
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• pp.160-164
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• 1994

In this study, we investigeated the anticarcinogenicity of various types and ages of ginseng extracts as an extended study using Yun's anticarcinogenicity test. Fresh ginseng at 1.5, 3, 4, 5 and 6 years was dried and powdered. And white ginseng was processed in the same way that of fresh ginseng after removal fo the ginseng cortex and fine root. For red ginsneg, fresh ginseng was steamed and dried. Each ginseng powder was extracted and extracts was freeze dried. Newborn N:GP(S) mice were given a single subcutaneous injection of 0.5 mg of benzo(a)pyrene(BP). Various types and ages of ginseng extracts at 2.5mg/ml were orally administered. All the mice were sacrificed at the 9th week. The following results were obtained. In the dried fresh ginseng extract treated group, the incidence of lung adenoma induced by BP was 63.9% and its incidence was reduced to 48.3%, 52.5%, 51.8%, 47.5% and 44.1% after co-treatment with 1.5, 3, 4, 5 and 6 year-dried fresh ginseng, respectively. The incidence of lung adenoma induced by BP on the white ginseng extract treated group was 41.3% and decreased to 31.0%, 46.0%, 44.0% and 26.5% after co-treatment with 3, 4, 5 and 6 year-white ginseng, respectively. In the red ginseng extract treated group, the incidence of lung adenoma induced by BP was 47.5% and its incidence diminished to 40.7%, 35.0%, 30.1%, 30.0% and 26.3% after co-treatment with 1.5, 3, 4, 5 and 6 year-red ginseng, respectively. From the above results, we concluded that a statistically significant anticarcinogenic effect was observed in extracts of 6 year-dried fresh ginseng, 6 year-white ginseng, and 4, 5 and 6 year-red ginseng and it is suggested that the anticarcinogenicity of ginseng varies according to the types and ages Key words Ginseng extract, types and ages. anticarcinogenic, newborn mice, lung tumor.