• 대한환경공학회지
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• 제32권11호
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• pp.1017-1023
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• 2010

본 연구에서는 지질매질체내에서 계면활성제(비이온성 계면활성제(Tween 20), 생계면활성제)가 박테리아(Bacillus subtilis ATCC 6633)의 이동 증진에 미치는 영향을 분석하였다. 계면활성제가 존재하는 다양한 실험조건에서 석영모래(입경분포: 0.5~2.0 mm, 평균입경: 1.0 mm)로 충진된 칼럼을 이용하여 박테리아의 이동에 관한 칼럼실험을 수행하였고, 박테리아 파과곡선으로부터 질량회수율과 부착효율 등을 정량화하였다. 실험결과, MSM(박테리아 성장에 필요한 무기물 배지)의 존재 하에서 매질체 표면에 박테리아의 부착이 상당히 증가하였는데(특히, 주입부분에), 이는 MSM으로 인한 이온강도의 증가 때문이다. 계면활성제가 존재할 경우에는, 계면활성제로 인하여 매질체내에서 박테리아 이동이 증진됨을 관찰할 수 있었다. 또한, MSM과 생계면활성제 주입방법에 따른 박테리아의 이동을 비교한 결과, 박테리아의 이동 증진을 위한 주입조건은 박테리아를 함유한 MSM용액보다 계면활성제를 선주입하거나, 또는 MSM용액과 계면활성제를 동시주입하는 것이 효과적임을 알 수 있었다. 본 연구를 통해 계면활성제의 존재와 주입방법이 박테리아의 이동에 영향을 미칠 수 있음을 알 수 있었다.

• 공업화학
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• 제10권6호
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• pp.843-847
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• 1999

본 연구에서는 유동층-화학증기침투에 의해 이염화이메틸규소(DDS)와 수소로부터 생성된 탄화규소를 활성탄에 증착시킨 세라믹 탄소/탄화규소복합체가 제조되었다. 4~12, 12~20, 20~40 mesh의 활성탄이 사용되었다. 증착 후 반응물인 이염화이메틸규소의 농도, 활성탄의 크기, 반응압력, 반응시간에 따른 반응후 각 시료의 표면적과 증착량 및 증착양상을 관찰하였다. 실험결과 DDS의 농도가 낮고 반응압력이 작을수록 시료 기공내에 고른 증착을 갖는 것을 알 수 있었다. 또한 기공직경과 표면적들이 어떠한 시점에서 최소값을 갖는 것으로 기공내부 증착에서 입자외부 표면 증착으로 바뀜을 알 수 있었다. DDS의 농도가 낮고 반응압력이 낮을 때 작은 탄화규소입자가 활성탄 표면에 더욱 고르게 증착되었다. 이 결과들은 SEM, TGA, 기공도측정장치, BET에 의해 확인되었다.

• 대한핵의학회지
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• 제12권2호
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• pp.33-40
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• 1978

Clinical features of 147 patients with biopsy-proven thyroid carcinomas were investigated from January, 1972 to April, 1978 at the Seoul National University Hospital with the following results. 1) The incidence of thyroid carcinomas according to their histopathological classification revealed 76.2% of papillary carcinoma, 19.0% of follicular carcinoma, and 3 cases of occult sclerozing carcinoma, 1 case of giant cell carcinoma and 1 case of metastatic melanoma. 2) The ratio of male to femle patients was 1:8.3 and showed no difference between papillary and follicular carcinomas. 3) The age distribution showed the peak incidence in the fourth decade (29.3%) followed by the fifth and sixth decades. 4) The average duration of illness from the onset of symptoms was about 5 years while it was 4.4 years and 7.6 years in the papillary and follicular carcinomas respectively. 5) The diameter of the thyroid masses was smaller than 5 cm in 53.6% of the patients, from 5 cm to 10 cm in 40.0% and larger than 10 cm in 6.4%. 6) In 36.4% of the patients with thyroid carcinomas the thyroid masses were fixed to adjacent tissues. 7) Metastasis to the regional lymph nodes was noted in 40.0% of the total cases, and in 45.2% and 17.6% of the papillary and follicular carcinomas respectively, while the lung and bone metastases were found in 10.0% and 4.4% in each type respectively. 8) 88.9% of the patients showed cold areas in the thyroid scans using $^{131}I$. 9) Typical psammoma bodies were observed in 21.3% of the cases in the microscopic examination of the pathological specimens. 10) The initial diagnosis of thyroid malignancy could be made before histological confirmation in 64.5% of the patients. 11) The clinical staging slightly modified from Schulz method revealed 43.6% of the patients in stage I, 26.4% in stage II, 20.9% in stags III and 9.1 % in stage IV. 12) The association with Hashimoto's thyroiditis was noted in 4 cases, with nodular goiter in 3 cases, and with follicular adenoma in 1 case.

• 대한핵의학회지
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• 제24권2호
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• pp.237-243
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• 1990

Pulmonary embolism demands rapid and accurate diagnosis. And ventilation imaging has greatly improved the diagnostic accuracy of pulmonary embolism in addition to perfusion imaging. Agents currently used include xenon-133, krypton-81m and technetium-99m radioaerosols. However radioactive gases are compromised by availability and cost for krypton-81m, radiation dose, gamma energy and non?physiologic behaviour for xenon-133. Radioaerosols of technetium-99m componds are rapidly cleared from the lung after inhalation, and their relative low effeciency (specific radioactivity) and wide distribution of particle sizes make them also suboptimum. A new ventilation agent, Technegas is a suspension of structured graphite ellipsoids with diameter below 20nm, labelled with $^{99m}Tc$ in a carrier gas of Argon. This report describes the authors' clinical experience with Technegas. This is the first reported clinical study of this agent in Korea. A comparison of Technegas and $^{99m}Tc-DTPA$ aerosol was performed in 12 patients with various pulmonary diseases such as COPD, pulmonary tuberculosis and pleural effusion. All patients were studied with $^{99m}Tc-DTPA$ aerosol inhalation and Technegas ventilation. In both studies image quality was assessed (1) semiquantitatively by scoring bronchial and gastric activity, (2) subjectively by direct visual comparison of peripheral lung images and (3) quantitatively by computing the peripheral penetration index(PI) for each lungs. The bronchial activites were seen in 7 out of 12 cases with $^{99m}Tc-DTPA$ aerosol and in 5/12 with Technegas. The gastric activities were seen in 5/12 and 1/12 cases respectively. The average values of PI were 61.26% with $^{99m}Tc-DTPA$ aerosol and 69.20% with Technegas (p>0.05). Using $^{99m}Tc-DTPA$ aerosol, COPD patients showed deposition in the central airways with poor visualization of the peripheral areas of the lungs. In Technegas studies these phenomena were less prominent, and the examination is well tolerated by pateients and requires only a minimum of patient cooperation. With superiority of easy availability and handling, better physical characteristics and favorable Image quality, Technegas is a Promising agent for lung ventilation scanning.

• 대한핵의학회지
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• 제20권1호
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• pp.59-65
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• 1986

Clinical features of 406 patients with histologically verified thyroid carcinomas were investigated from May, 1978 to April, 1985 at the Seoul National University Hospital with the following results. 1) The incidence of thyroid cancer according to their histological classification was 79.8% of papillary carcinoma, 14.5% of follicular carcinoma, 1.5% of medullary carcinoma, 2.2% of anaplastic carcinoma, 2 cases of squamous carcinoma and 3 cases of lymphoma. 2) The age distribution showed the peak incidence in the fourth decade (25.1%), followed by the fifth and the third decade. 3) The ratio of male to female patients was 1 : 6.1. The ratio is 1 : 5.9 in papillary carcinoma and 1 : 8.8 in follicular carcinoma. 4) The mean age was 40.2 year in papillary carcinoma, 37.4 year in follicular carcinoma. 36.5 year in medullary carcinoma, 60.3 year in anaplastic carcinoma, 62.0 year in squamous carcinoma, 59.7 year in lymphoma. 5) The diameter of the thyroid masses was smaller than 1.5cm in 19.9% of the patients, from 1.5cm to 5cm in 50.5%, from 5cm to 10cm in 25.4% and larger than 10cm in 25.4%. 6) Metastasis to the regional lymph nodes at diagnosis was noted in 44.2% of total patients, and distant metastasis was 5%, and local infiltration was 44.2%. 7) The clinical staging was revealed 42.1% of the patients in stage I, 9.1% in stage II, 35.7% in stage III, 5.2% in stage IV, and 7.9% in undetermined stage.

• 환경생물
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• 제19권1호
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• pp.79-86
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• 2001

바지락포자층 Perkinsus는 Apicomplexa 문에 속하는 기생성 원생동물로서 유럽에서는 바지락의 대량폐사 원인 생물로 잘 알려져 있으며 우리나라에서도 90년대 초반부터 나타나고 있는 바지락 폐사의 원인생물로 추정되고 있다. 이 연구는 우리나라 바지락포자충 감염분포 조사의 일환으로 제주 연안에 서식하는 바지락의 바지락포자충 감염 현황과 감염도, 조직병리학적 현상, 유주자 형성 그리고 서식지의 퇴적물 조성에 따른 감염 특성을 조사하기 위하여 실시되었다. Ray의 Fluid Thioglycollate Medium (FTM) 방법과 Choi의 NaOH lysis 방법을 이용한 진단결과 김녕항과 용머리 지역의 바지락은 비감염 상태였으며, 이들 지역을 제외한 지역의 바지락포자충의 발현율은 표선 100%, 성산항 70%, 금능 63%, 종달리 33%, 이호 21%, 모슬포 17%,서귀포 14%, 순으로 나타났다. 바지락 습중량 1g당 표선 98,430 세포, 성산 78,553 세포, 금능 18,980 세포, 종달리 4,290 세포, 이호 1,527 세포, 모슬포 1,069 세포, 서귀포 853 세포의 바지락포자충이 검출되었다. 조직병리학적 검사결과 직경 5-10$\mu\textrm{m}$인 원형의 trophozoite가 바지락의 소화맹낭과 아가미에 분포하고 있음이 확인되었으며 숙주의 혈구집중 현상도 관찰되었다. 유주자는 FTM에서 2일동안 배양된 hypnospore를 $25^{\circ}C$의 해수에서 2일간 배양하였을 때 세포분열을 거쳐 방출관을 통하여 방출됐다. 이상의 조사 결과 제주 연안에 서식하고 있는 대부분의 바지락이 바지락포자충에 감염되어 있음이 확인되었다. 그러나 우리나라 남ㆍ서해안에서 보고된 바지락 포자충 감염율이나 감염도 보다는 매우 낮은 수준이었다.

• 한국식품과학회지
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• 제46권2호
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• pp.135-142
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• 2014

국내에서 육종한 11가지 고구마의 전분 특성을 구명하여 새로운 식품 소재의 개발을 위한 기초자료로 이용하고자 전분의 이화학, 호화 및 소화 특성을 조사하였다. 아밀로스 함량은 12.5-17.4%의 범위를 보였으며, 아밀로펙틴 가지 사슬 분포는 시료 간에 유사하였다. 증미 전분의 아밀로펙틴 분자량이 가장 컸으며 대유미 전분은 가장 낮은 값을 보였다. 모든 고구마 전분의 X선 회절 양상은 C형 중에서도 A형에 가까운 $C_a$형을 나타내었다. 시차주사열량계로 측정한 열 특성에서 11품종 고구마 전분 중 신율미와 증미의 호화 온도가 높았고, 해피미는 낮았다. Rapid Visco Analyser로 페이스트 특성을 살펴보았을 때, 호화시간은 전분 입자의 크기, 최고점도, 강하점도와 음의 상관을 나타내었으며, 해피미가 가장 낮은 호화 온도와 치반점도를 보였고 강하점도와 최고점도 및 최종점도가 높았다. 소화 특성에서 증미의 RS 함량이 가장 많았으며, 신율미와 해피미는 SDS 함량이 많았다.

• 에너지공학
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• 제10권3호
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• pp.223-232
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• 2001

보염기 후류에 형성되는 화산회생의 보염특성을 고찰하기 위하여 연료 분출각의 변화, 난류발생격자의 설치, 재순환영역 내에 보조 연료의 공급에 따른 화염의 안정범위, 재순환영역의 길이 및 온도, 재순환영역주변의 난류강도 분포를 측정, 고찰하였다. 재순환영역의 길이는 주 연료 분출량의 변화에 따른 영향을 받지 않지만, 연료 분출각 및 주류유속의 변화, 보조 연료의 공급 난류발생격자의 설치 등에 따라 영향을 받는다. 확산화염의 경우 일반적으고 재순환영역의 길이가 길수록 보염성이 불량하지만, 난류발생격자를 설치한 경우에는 재순환영역의 길이가 길수록 보염성이 양호하다. 재순환영역의 온도는 연료 분출각의 변화, 보조 연료의 공급, 난류발생격사의 설치 등에 따라 영향을 받으며, 이론 혼합기 상태에서 최고값에 도달한다. 일반적으로 재순환영역의 온도가 낮을수록 보염성이 양호하지만. 난류발생격자를 설치한 경우에는 재순환영역의 온도가 낮을수록 보염성이 불량하다. 화염이 형성되는 보염기 후류 영역에 대한 난류강도는 격자의 직경이나 구속비가 큰 난류발생 격자를 설치한 경우에 크게 나타나며, 난류강도가 강 할수록 보염성이 불량하다. 연료 분출각의 변화, 난류발생격자의 설치, 재순환영역 내에 보조 연료의 공급 등의 방법으로 확산화염의 보염특성을 제어할 수 있다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권1호
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• pp.36-48
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• 2008

To repair bone defects in the oral and maxillofacial field, bone grafts including autografts, allografts, and artificial bone are used in clinical dentistry despite several disadvantages. The purpose of this study was to evaluate new bone formation and healing in rat calvarial bone defects using hydroxyapatite (HA, $Ca_{10}[PO_4]_6[OH]_2,\;Bongros^{(R)}$, Bio@ Co., KOREA) and tricalcium phosphate (${\beta}-TCP,\;Ca_3[PO_4]_2$, Sigma-Aldrich Co., USA) mixed at various ratios. Additionally, this study evaluated the effects of type I collagen (Rat tail, BD Biosciences Co., Sweden) as a basement membrane organic matrix. A total of twenty, 8-week-old, male Sprague-Dawley rats, weighing 250-300g, were divided equally into a control group (n=2) and nine experimental groups (n=2, each). Bilateral, standardized transosseous circular calvarial defects, 5.0 mm in diameter, were created. In each experimental group, the defect was filled with HA and TCP at a ratio of 100:0, 80:20, 70:30, 60:40, 50:50, 40:60, 30:70, 20:80, and 0:100 with or without type I collagen. Rats were sacrificed 4 and 8 weeks post-operation for radiographic (standardized plain film, Kodak Co., USA), histomorphologic (H&E [Hematoxylin and Eosin], MT [Masson Trichrome]), immunohistochemical staining (for BMP-2, -4, VEGF, and vWF), and elementary analysis (Atomic absorption spectrophotometer, Perkin Elmer AAnalyst $100^{(R)}$). As the HA proportion increased, denser radiopacity was seen in most groups at 4 and 8 weeks. In general radiopacity in type I collagen groups was greater than the non-collagen groups, especially in the 100% HA group at 8 weeks. No new bone formation was seen in calvarial defects in any group at 4 weeks. Bridging bone formation from the defect margin was marked at 8 weeks in most type I collagen groups. Although immunohistochemical findings with BMP-2, -4, and VEGF were not significantly different, marked vWF immunoreactivity was present. vWF staining was especially strong in endothelial cells in newly formed bone margins in the 100:0, 80:20, and 70:30 ratio type I collagen groups at 8 weeks. The calcium compositions from the elementary analysis were not statistically significant. Many types of artificial bone have been used as bone graft materials, but most of them can only be applied as an inorganic material. This study confirmed improved bony regeneration by adding organic type I collagen to inorganic HA and TCP mixtures. Therefore, these new artificial bone graft materials, which are under strict storage and distribution systems, will be suggested to be available to clinical dentistry demands.

• 대한치과보철학회지
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• 제43권1호
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• pp.120-131
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• 2005

Statement of problem. More than 70% of patients who need the implant supported restoration are parially edentulous. The principles of design for implant supported fixed partial denture in mandibular posterior region are many and varied. Jurisdiction for their use is usually based on clinical evaluation. There are several areas or interest regarding the design of implant supported fixed partial denture in mandibular posterior region. 1) Straight and tripod configuration in implant placement, 2) Two restoration types such as individualized and splinted restorations. Purpose. The purpose of this study was to compare the amount and distribution of stress around the implant fixtures placed in the mandibular posterior region with two different arrangements and to evaluate the effects of splinting using the photoelastic stress analysis. Material & methods. 1) Production of study model: Mandibular partially edentulous model was waxed-up and duplicated with silicone and two models were poured in stone. 2) Fixture installation and photoelastic model construction: Using surveyor(Ney, USh), 3 fixtures(two 4.0 $\times$13 mm, one 5.0$\times$10 mm, Lifecore, USA) were insta)led in straight & tripod configurations. Silicone molds were made and poured in photoelastic resin (PL-2. Measurements group, USA). 3) Prostheses construction: Four 3-unit bridges (Type III gold alloy, Dongmyung co., Korea) were produced with nonhexed and hexed UCLA abutments and fitted with conventional methods. The abutments were tightened with 30 Ncm torque and the static loads were applied at 12 points of the occlusal surface. 4) Photoelastic stress analysis : The polarizer analyzer system with digital camera(S-2 Pro, Fujifilm, Japan) was used to take the photoelastic fringes and analysed using computer analysis program. Results. Solitary hexed UCLA restoration developed different stress patterns between two implant arrangement configurations, but there were no stress transfer to adjacent implants from the loaded implant in both configurations. However splinted restorations showed lesser amount of stresses in the loaded implants and showed stress transfer to adjacent implants in both configurations. Solitary hexed UCLA restoration with tripod configuration developed higher stresses in anterior and middle implants under loading than implants with straight configurations. Splintied 3 unit fixed partial dentures with tripod configuration showed higher stress development in posterior implant under loading but there were no obvious differences between two configurations. Conclusions. The tripod configuration of implant arrangement didn't show any advantages over the straight configuration. Splinting of 3 unit bridges with nonhexed UCLA abutments showed less stress development around the fixtures. Solitary hexed UCLA restoration developed tilting of implant fixture under offset loads.