• 한국환경과학회지
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• 제15권8호
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• pp.701-718
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• 2006

The average ratio of the daily UV-B to total solar (75) irradiance at Busan (35.23$^{\circ}$N, 129.07$^{\circ}$E) in Korea is found as 0.11%. There is also a high exponential relationship between hourly UV-B and total solar irradiance: UV-B=exp (a$\times$(75-b))(R$^2$=0.93). The daily variation of total ozone is compared with the UV-B irradiance at Pohang (36.03$^{\circ}$N, 129.40$^{\circ}$E) in Korea using the Total Ozone Mapping Spectrometer (TOMS) data during the period of May to July in 2005. The total ozone (TO) has been maintained to a decreasing trend since 1979, which leading to a negative correlation with the ground-level UV-B irradiance doting the given period of cloudless day: UV-B=239.23-0.056 TO (R$^2$=0.52). The statistical predictions of daily total ozone are analyzed by using the data of the Brewer spectrophotometer and TOMS in East Asia including the Korean peninsula. The long-term monthly averages of total ozone using the multiplicative seasonal AutoRegressive Integrated Moving Average (ARIMA) model are used to predict the hourly mean UV-B irradiance by interpolating the daily mean total ozone far the predicting period. We also can predict the next day's total ozone by using regression models based on the present day's total ozone by TOMS and the next day's predicted maximum air temperature by the Meteorological Mesoscale Model 5 (MM5). These predicted and observed total ozone amounts are used to input data of the parameterization model (PM) of hourly UV-B irradiance. The PM of UV-B irradiance is based on the main parameters such as cloudiness, solar zenith angle, total ozone, opacity of aerosols, altitude, and surface albedo. The input data for the model requires daily total ozone, hourly amount and type of cloud, visibility and air pressure. To simplify cloud effects in the model, the constant cloud transmittance are used. For example, the correlation coefficient of the PM using these cloud transmissivities is shown high in more than 0.91 for cloudy days in Busan, and the relative mean bias error (RMBE) and the relative root mean square error (RRMSE) are less than 21% and 27%, respectively. In this study, the daily variations of calculated and predicted UV-B irradiance are presented in high correlation coefficients of more than 0.86 at each monitoring site of the Korean peninsula as well as East Asia. The RMBE is within 10% of the mean measured hourly irradiance, and the RRMSE is within 15% for hourly irradiance, respectively. Although errors are present in cloud amounts and total ozone, the results are still acceptable.

• Restorative Dentistry and Endodontics
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• 제13권2호
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• pp.323-334
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• 1988

The purpose of this study was to observe the effect of dentin surface conditioners on the dentin surfaces. Freshly extracted human molars were used in this study. They were stored at $4^{\circ}C$ saline solution before experiment. The crown portions of the teeth were cut in various directions by means of wet diamond point to expose dentin which include transverse, vertical oblique, horizontal and oblique cut to the long axis (Fig. 1). Each tooth was then mounted with self curing acrylic resin in brass ring to expose the flattened dentin surfaces. Final finish was accomplished by grinding the dentin specimens with wet No. 180 and No. 600 grit silicon carbide abrasive paper until a 6.0mm in diameter on a dentin surface was exposed without pulp exposure. The specimens were divided into 9 groups according to the modes of dentin treatment procedure. The following surface treatments were applied on these preparation surfaces; Group 1: unetched (control group) after finish with No. 600 silicon carbide abrasive paper. Group 2: etched with 30% phosphoric acid for 60s Group 3: etched with 10-3 solution for 60s Group 4: Cleaned with 5% NaOCl for 30s Group 5: applied Dentin Adhesit Group 6: cleaned with 5% NaOCl followed by applying the Dentin Adhesit$^{(R)}$ Group 7: applied Photo Bond on the unetched dentin followed by applying the Photo Clearfil Bright Group 8: Etched with 30% phosphoric acid followed by applying Photo Bond and Photo Clearfil Bright Group 9: etched with 10-3 solution followed by applying Photo Bond and Photo Clearfil Bright All the specimens were stored in $37^{\circ}C$ under 50% relative humidity for 24 hours before observations. The specimens in 7, 8, and 9 group, omitting the group 1 to 6, were demineralized in 10% HCl for 10s in order to observe the resin tags. All the specimens in each group were then dried at room temperature. The dried specimens were ion coated with Eiko ion coater (Eiko-engineering Co.), and observed in Hitachi S-430 Scanning electron microscope (Hitachi, Co. Tokyo) at 15KV. The following results were obtained as follows; 1. The smear layers were still remained in group 1,2,4,5, and 6. 2. There is no effect of 5% NaOCl and 30% phosphoric acid on the changes of dentin morphology 3. The dentin treated with 10-3 solution, indicating the tubules opened when the smear layer and the dental plug dissolved. 4. In case of applying the bonding agents the resin tag was not formed at the deep area of dentinal tubules, but in case of applying the Dentin Adhesit$^{(R)}$ that was not.

• 한국어류학회지
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• 제27권4호
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• pp.257-262
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• 2015

한국고유종인 왕종개의 안구를 관찰하고 망막에 존재하는 시각세포의 구조를 광학현미경과 주사전자현미경을 이용하여 조사하였다. 왕종개의 안구는 $3.53{\pm}0.2mm$의 크기였으며 두장대 안경비율은 $14.08{\pm}0.7$이였다. 시각세포의 수직단면을 확인한 결과 망막은 여러 층으로 구성되어 있었으며 전체 망막의 두께는 $216.42({\pm}13.36){\mu}m$였으며, 시각세포의 핵이 존재하는 바깥핵층의 두께는 13.42 $({\pm}2.16){\mu}m$였다. 이형 이중 원추세포 중 긴 원추세포는 $26.42{\pm}1.7{\mu}m$의 길이였으며 직경은 $5.12{\pm}0.6{\mu}m$로 확인되었다. 짧은 원추세포는 $16.82{\pm}1.1{\mu}m$의 길이였으며 직경은 긴 원추세포와 유사한 $5.10{\pm}0.31{\mu}m$로 확인되었다. 간상세포는 길이 $40.13{\pm}2.4{\mu}m$였으며 직경 $3.95{\pm}0.4{\mu}m$로 확인되었다. 시각세포의 수평단면을 확인한 결과 이형 이중 원추세포가 규칙적인 배열로 인해 열 배열(row-type)의 모자이크 패턴으로 나타났다. 긴 원추세포와 짧은 원추세포가 하나의 쌍을 이루었으며 긴 원추세포는 내절이 절단되어 eosin에 염색되었으며 짧은 원추세포는 외절이 절단되어 hematoxylin에 염색되었다. 전자현미경을 통해 미세구조를 확인한 결과 내절과 외절로 구분되고 내절은 장타원형으로 확인되었다. 외절에는 디스크구조의 판상을 확인할 수 있었으며 내절과 외절을 연결해주는 배상극 (calyceal processes)들이 가장자리에 분포하고 있었다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권6호
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• pp.398-403
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• 2012

Purpose: Mandible resection and discontinuity defect created lead to aesthetic and functional problems. The iliac crest bone graft exhibits relative ease for bone harvesting, possibility of two team approach, ability to close the wound primarily, large amount of corticocancellous bone and relatively few complications. Whereas the use of free vascularized flaps has donor site morbidity and worse-fitting bone contour, the use of nonvascularized iliac bone graft has advantages in the operation time and patients' recovery time. So, nonvascularized iliac bone graft could be an attractive option. Methods: Twenty-one patients (M:F=1:1.1) underwent iliac crest bone harvesting for reconstruction of mandibular discontinuity defect (mean length : $61.6{\pm}17.8$ mm), from May 2005 to October 2011 at the Department of Oral and Maxillofacial Surgery in Kyungpook National University. The average age was $44.1{\pm}16.4$ years and the mean follow up periods was $28.2{\pm}22.7$ months. Bone resorption rate, according to age, sex, primary lesion, location and distance of defect, type of fixation plate, time of graft and pre-operative radiation therapy, were measured in each patient. Results: The mean bone resorption rate was $16.1{\pm}9.0%$. Bone resorption rate was significantly increased in mandibular defect that is over 6 cm in size (P=0.015, P<0.05) and the cases treated pre-operative radiation therapy (P=0.017, P<0.05). All was successfully fixed and maintained for the long-term follow-up. There were a few donor site complications and almost all patients were shown favorable outcome without severe bone resorption in this study. Conclusion: The nonvascularized iliac bone graft seems to be a reasonably reliable treatment option for reconstruction of mandibular discontinuity defects.

• Journal of Periodontal and Implant Science
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• 제36권1호
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• pp.27-37
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• 2006

Although the main purpose of periodontal treatment to regenerate is the complete regeneration of periodontal tissue due to periodontal disease, most of the treatment cannot meet such purpose because healing by long epithelial junction. Therefore, diverse materials of resorbable and non-resorbable have been used to regenerate the periodontal tissue. Due to high risk of exposure and necessity of secondary surgical procedure when using non-resorbable membrane, guided tissue regeneration using the resorbable membrane has gain popularity, recently. However, present resorbable membrane has the disadvantage of not having sufficient time to regenerate date to the difference of resorption rate according to surgical site. Meanwhile, other than the structure stability and facile manipulation, acellular dermal matrix has been reported to be a possible scaffold for cellular proliferation due to rapid revascularization and favorable physical properties for cellular attachment and proliferation. The purpose of this study is to estimate the influence of acellular dermal matrix on periodontal ligament, cementum and alveolar bone when acellular dermal matrix is implanted to 1-wall alveolar bone defect. 4 dogs of 12 to 16 month old irrelevant to sex , which below 15Kg of body weight, has been used in this study. ADM has been used for the material of guided tissue regeneration. The 3rd premolar of the lower jaw was extracted bilaterally and awaited for self-healing. subsequently buccal and lingual flap was elevated to form one wall intrabony defect with the depth and width of 4mm on the distal surface of 2nd premolar and the mesial surface of 4th premolar. After the removal of periodontal ligament by root planing. notch was formed on the basal position. Following the root surface treatment, while the control group had the flap sutured without any treatment on surgically induced intrabony defect. Following the root surface treatment, the flap of intrabony defect was sutured with the ADM inserted while the control group sutured without any insertion. The histologic specimen was observed after 4 and 8 weeks of treatment. The control group was partially regenerated by periodontal ligament, new cementum and new alveolar bone. the level of regeneration is not reached on the previous formed notch. but, experimental group was fully regenerated by functionally oriented periodontal ligament fiber. new cementum and new alveolar bone. In conclusion, we think that ADM seems to be used by scaffold for periodontal ligament cells and the matrix is expected to use on guided tissue regeneration.

• 대한치과보철학회지
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• 제19권1호
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• pp.39-45
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• 1981

Distal-extension removable partial dentures have long been implicated in the increase in mobility and the destruction of the supporting structures of the primary abutment teeth. Various clasping systems have traditionally been used to retain distal extension removable partial dentures, and other designs have been proposed to minimize torquing forces on the abutment teeth. Most recent studies investigating the effects of removable partial dentures on abutment teeth have been performed in it laboratory setting. Results obtained from in vitro research have given dentists insight into removable partial denture design, but laboratory test model cannot be constructed that simulates actual functional or parafunctiona1 movements and forces. The purpose of this study was to clinically evaluate the degree of tooth mobility produced by two clasping systems (suprabulge type and infrabulge type) used for distal extension removable partial dentures. Akers clasp and R.P.I. system were selected for the evaluation, and four patients required a distal extension removable partial denture on the mandibular arch were selected for participation in the study. Two partial dentures were constructed in the same condition expect the design of clasp. All abutments in the study were mandibular first or second premolars. Measurements of mobility were made with a research tool designed by $M\"{u}hlemann$. This instrument, periodontometer, measures tooth mobility in the mouth by means of a dial gauge accurated to 0.01mm when the tooth is stressed with a force meter. Lingual and buccal deflection of abutment tooth was measured using buccal and lingual pressure. The amount of force applied was 500gm. Tooth mobility tests were made at four key stages; 1. Before insertion of the first removable partial denture, baseline mobility was establsihed. 2. After wearing of the first prosthesis, measurement was made at weekly intervals for 4 weeks. 3. The removable partial denture was then taken from the patient, and tooth mobility was measured again at weekly intervals until the patient's established baseline mobility had returned. 4. The second prosthesis of different clasp design was worn for a month and evaluated in the same manner as the first. The sequence of placement of clasping system was alternated between patients. The following results were obtained from this study; 1. The mobility of abutment tooth increased during the initial stage of wear and returned to baseline mobility after removal of removable partial dentures. 2. The mobility of abutment tooth showed no difference between Akers clasp and I-bar clasp during the 4-week test period. 3. All teeth tested showed greater mobility toward the buccal than the lingual direction.

• The Journal of Advanced Prosthodontics
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• 제2권2호
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• pp.33-38
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• 2010

PURPOSE. Marginal fit is a very important factor considering the restoration's long-term success. However, adding porcelain to copings can cause distortion and lead to an inadequate fit which exposes more luting material to the oral environment and causes secondary caries. The purpose of this study was to compare the marginal fit of 2 different all-ceramic crown systems before and after porcelain veneering. This study was also intended to verify the marginal fit of crowns originated from green machining of partially sintered blocks of zirconia (Lava CAD/CAM system) and that of crowns obtained through machining of fully sintered blocks of zirconia (Digident CAD/CAM system). MATERIALS AND METHODS. 20 crowns were made per each system and the marginal fit was evaluated through a light microscope with image processing (Accura 2000) at 50 points that were randomly selected. Each crown was measured twice: the first measurement was done after obtaining a 0.5 mm coping and the second measurement was done after porcelain veneering. The means and standard deviations were calculated and statistical inferences among the 2 groups were made using independent t-test and within the same group through paired t-test. RESULTS. The means and standard deviations of the marginal fit were $61.52{\pm}2.88{\mu}m$ for the Digident CAD/CAM zirconia ceramic crowns before porcelain veneering and $83.15{\pm}3.51{\mu}m$ after porcelain veneering. Lava CAD/CAM zirconia ceramic crowns showed means and standard deviations of $62.22{\pm}1.78{\mu}m$ before porcelain veneering and $82.03{\pm}1.85{\mu}m$ after porcelain veneering. Both groups showed significant differences when analyzing the marginal gaps before and after porcelain veneering within each group. However, no significant differences were found when comparing the marginal gaps of each group before porcelain veneering and after porcelain veneering as well. CONCLUSION. The 2 all-ceramic crown systems showed marginal gaps that were within a reported clinically acceptable range of marginal discrepancy.

• 한국지역사회생활과학회지
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• 제16권4호
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• pp.3-13
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• 2005

본 실험은 야산에서 재배한 더덕의 장기 저장을 목적으로 포장재와 온도를 달리하여 30일간 저장하면서 pH, 수분, 회분, 일부 무기성분과 사포닌의 함량 변화를 조사하였다. 신선한 더거 즙액의 pH는 5.3이었고 30일에는 $4.2{\∼}4.3$으로 유의적으로 감소하였다. 수분함량은 저장 온도보다는 포장재질에 의해 영향 받는 정도가 컸다. 회분함량은 저장기간이 증가할수록 크게 감소하여, 30일 후에는 신선더덕의 $14{\∼}67\%$만을 함유하고 있었다. 더덕의 무기성분 함량은 종류에 따라 정도는 다르지만 저장기일이 증가함에 따라 감소하였으며, 이는 더덕의 pH와 회분함량의 변화와 관련이 있을 것으로 여겨진다. 저장 기간이 증가함에 따라 더덕 즙액의 색탁은 약간 어두어졌고, 15일 저장 시 약간 붉은 색을 띠는 경향이 뚜렷했으나 점차 감소하였으며, 황색도는 저장조건별로 변화 양상이 달랐다. 조사포닌 함량은 1g당 29.7mg이었고, 30일간 저장 시 항균포장을 하거나 냉장 저장을 한 경우에는 초기 함량과 유의적 차이가 없었으나 마대포장-실온저장 더덕은 30일간 저장 시 24.9mg으로 유의적으로 감소하였다. Codonoposide 함량은 건조 더덕 100g 중 382mg으로, 조사포닌 총량의 약 $8\%$였으며, 15일 저장 시 마대포장-실온저장 더덕은 약간 증가한 반면, 나머지 조건에서는 감소하였고, 30일 저장 시에는 $304{\∼}365mg$으로 초기 시료보다 낮아져, 전반적으로는 감소 경향을 보였으나 모든 저장조건에서 유의적인 변화는 아니었다. 이상의 결과로 미루어 야산에서 재배된 더덕의 장기 저장 조건은 항균포장-냉장저장인 것으로 보인다.

• 치과방사선
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• 제26권2호
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• pp.133-145
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• 1996

Aspirating or swallowing foreign bodies is a common occurrence. If they are wholly or partly radiopaque, their localization in and progress through the gastrointestinal tract can be more effective. Of the dental origin foreign materials swallowed, the most common things are fragments of anterior maxillary partial denture. But the radiopacity of denture base resins is not sufficient to determine the location of the objects. The purpose of this study was to develop a radiopaque dental acrylic resin, which has clinically detectible radiopacity with minimal change of mechanical properties and color. The radiopacity, color change(CIE 6..E) and microhardness of acrylic resins were determined after mixing barium sulfate or iodide compound. Thermocycling course was conducted to determine the change of characteristic of resins after using for a long time in the mouth. Five or ten percent of barium sulfate to total weight of cured material was mixed with heat curing dental acrylic resin or chemically curing orthodontic resin. In the case of iodide compound, the mixing ratio was two or three percent. After mixing the high radiopaque materials, resin was cured to 20×20×2 mm plate, polished with #600 sand paper and finally polished with Microcloth(Buehler). The specimens were thermocycled in 5 and 55 t distilled water for 2,000 times, and the measurement of radiopacity, color and Vickers hardness was repeated every 500 times thcrmocycling. The radiopacity of specimens on the X -ray films was measured with densitometer(X-rite). The color change was detennined with differential colorimeter(Model TC-6FX, Tokyo Denshoku), and the Vickers hardness number was measured with microhardness tester(Mitsuzawa). The following results were obtained : 1. All the three variables, the kinds of acrylic resins, the mixing or the kinds of high radiopaque materials and thermocycling, had combined effect on the radiopacity of the dental acrylic resins(p<0.0l). 2. The two variables, the mixing or the kinds of high radiopaque materials and thermocycling, influenced on the radiopacity of the dental acrylic resins(p<0.01). But the kinds of acrylic resins did not influence on the color change of mixed dental acrylic resins(p>0.05). 3. Each of the three variables, the kinds of acrylic resins, the mixing or the kinds of high radiopaque materials and thermocycling, influenced on the radiopacity of dental acrylic resins(p<0.0l). 4. The high radiopaque materials used in this study did not yield clinically usable radiopacity, and the color change was great after mixing those materials.

• 디지털융복합연구
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• 제11권9호
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• pp.365-370
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• 2013

Image J 프로그램은 digital image 분석 또는 생명 공학적 분석에 사용되고 있다. 다양한 동물실험 중에서도 마우스 두개골 결손모델(Mouse calvarial defected model)은 조직공학자들에게 대표적으로 사용되고 있는 뼈의 결손모델이다. 이러한 마우스 두개골 결손 모델은 뼈의 재생 또는 새로운 지지체(scaffold)의 재생효과 실험에 사용되고 있다. 마우스 두개골에 지름 4mm의 원형 결손을 만들어 각종 실험재료를 처리하여 파괴된 마우스 두개골 뼈의 재생에 관련하여 측정하는 실험이 주를 이룬다. 실험 후에 마우스를 희생하여 대부분 헤마톡실린과 에오신 염색을 통하여 분석을 하게 된다. 다른 한편으로는 마이크로 시티(u-CT)를 사용하여 정량적인 분석을 한다. 하지만 이는 시간이 오래 걸리고 고가의 비용이 드는 단점이 있다. 이번 실험은 마우스 두개골 결손 모델 시에 프리쉐어 프로그램인 Image J를 통하여 간단하게 마우스 두개골 결손 뼈의 재생량을 2D X-ray 상으로 농도를 측정하여 정량적인 분석을 실행하였다. 결론적으로 Image J를 사용한 농도 분석법은 빠르고 정확하게 뼈의 재생량을 상대적으로 비교함으로써 신생 뼈의 관한 재생 실험자에게 도움을 줄 수 있을 것으로 사료된다.