• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 단조 심포지엄
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• pp.185-194
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• 1999

This paper suggests the new techmology to control metal flow in order to reduce the number of preforming and machining for the cold forged product with complex geometry. This technology can be summarized the complex forming, which consists of bulk forming and sheet forming, and multi-action forging, which be preformed double action dies. To analyze the process, finite element simulation has been performed. The proposed technology is applied to hub which is part of air conditioner clutch. According to the result of this study, the relative velocity of mandrel and punch is primary process variable.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제13권1호
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• pp.1-6
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• 2010

The small bowel is the most difficult intestinal segment to examine. Radiologic tests are mostly insensitive and double-balloon enteroscopy is unsuitable for the younger child. Capsule endoscopy is a novel wireless method of investigation of the small bowel. The primary indications for capsule endoscopy include evaluation of obscure gastrointestinal bleeding, small bowel Crohn's disease, and polyposis syndromes. Capsule endoscopy offers an accurate and effective means of investigating the small bowel in children. Capsule retention is a potential complication of capsule endoscopy. This review provides the indications, safety, and limitations of wireless capsule endoscopy in children.

• 대한소아치과학회지
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• 제31권2호
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• pp.136-143
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• 2004

이중치는 유치열에서 흔히 나타나는 발육 이상으로 후속 영구치의 결손, 융합, 형태 이상 등을 일으킬 수 있다. 본 연구에서는 2003년 1월부터 9월까지 원광대학교 치과병원 소아치과에 내원한 유치열기 및 혼합치열기 어린이 1,803명을 대상으로 유치열에서 나타나는 다양한 유형의 이중치를 악궁에서의 위치에 따라 분류하고 그에 따른 영구치의 발육 이상을 평가하였으며 동시에 이중치의 치관 및 치근의 형태 및 융합 정도에 따라 이중치를 네 가지 유형으로 분류한 Tannenbaum과 Ailing의 기준에 따라 이중치를 분류하고 그에 따른 영향도 평가하여 다음과 같은 결과를 얻었다. 1. 이중치는 49명(2.7%)이었고, 이중 5명의 어린이에서 양측성 이중치를 보이고 있었으며, 세 개의 치관 및 치근을 보이는 삼중치를 갖는 경우도 1명에서 나타났다. 2. 이중치는 하악 치열에서 현저히 높은 빈도로 나타났으며, 하악 유중절치와 유측절치가 융합된 경우 및 하악 유측절치와 유견치가 융합된 경우에서 유사하게 높게 나타났다. 하지만 후속 영구치가 결손되는 빈도는 유중절치와 유측절치가 융합된 경우(23.8%)보다 유측절치와 유견치가 융합된 경우(73.9%)에서 훨씬 높게 나타났다. 3. 상악의 경우는 오직 유중절치와 유측절치 부위에서만 이중치가 발견되었는데, 이중 유중 절치와 유측절치가 융합된 경우(75%) 특히 후속 영구치의 결손 빈도가 높았다. 4 이중치의 유형별로는 융합된 두개의 치관 및 치근을 갖는Type IV의 발생율이 가장 높았고(51.9%) 이에 따라 후속 영구치도 높은 빈도로 결손되었다(60.7%). 하지만 영구치 결손 빈도만으로는 큰 치관과 큰 치근을 갖는 Type II에서 가장 높았다(75%).

• Journal of Pharmaceutical Investigation
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• 제34권5호
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• pp.369-377
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• 2004

The objective of this study was to investigate the patterns of protein leaching to an external phase during an ethyl acetate-based, double emulsion microencapsulation process. An aqueous protein solution (lactoglobulin, lysozyme, or ribonuclease; $W_1$) was emulsified in ethyl acetate containing poly-d,l-lactide-co-glycolide 75:25. The $W_1/O$ emulsion was transferred to a 0.5% polyvinyl alcohol solution saturated with ethyl acetate $(W_2)$. After the double emulsion was stirred for 5, 15, 30, or 45 min, additional 0.5% polyvinyl alcohol $(W_3)$ was quickly added into the emulsion. This so-called quenching step helped convert emulsion microdroplets into microspheres. After 2-hr stirring, microspheres were collected and dried. The degree of protein leaching to $W_2$ and/or $W_3$ phase was monitored during the microencapsulation process. In a separate, comparative experiment, the profile of protein leaching to an external phase was investigated during the conventional methylene chloride-based microencapsulation process. When ethyl acetate was used as a dispersed solvent, proteins continued diffusing to the $W_2$ phase, as stirring went on. Therefore, the timing of ethyl acetate quenching played an important role in determining the degree of protein microencapsulation efficiency. For example, when quenching was peformed after 5-min stirring of the primary $W_1/O$ emulsion, the encapsulation efficiencies of lactoglobulin and ribonuclease were $55.1{\pm}4.2\;and\;45.3{\pm}7.6%$, respectively. In contrast, when quenching was carried out in 45 min, their respective encapsulation efficiencies were $39.6{\pm}3.2\;and\;29.9{\pm}11.2%$. By sharp contrast, different results were attained with the methylene-chloride based process: up to 2 hr-stirring of the primary and double emulsions, less than 5% of a protein appeared in $W_2$. Afterwards, it started to partition from $W_1\;to\;W_2/W_3$, and such a tendency was affected by the amount of PLGA75:25 used to make microspheres. Different solvent properties (e.g., water miscibility) and their effect on microsphere hardening were to be held answerable for such marked differences observed with the two microencapsulation processes.

• Journal of Dental Anesthesia and Pain Medicine
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• 제21권6호
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• pp.547-556
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• 2021

Background: This study aimed to determine the efficacy of Physics Forceps in pediatric dental extractions. Methods: This was a double-blind, randomized controlled trial with a parallel-arm design and identical allocation ratio (1:1). Children (n=104) were randomly divided into two groups for extraction of mandibular primary teeth (group I: Physics Forceps; group II: conventional forceps). The outcome variables assessed in the study were the time taken for extraction, pre- and postoperative anxiety (using RMS pictorial scale), incidence of fractured teeth, and postoperative pain on the first and third days (using the Wong-Baker faces pain scale). Results: A significant reduction (P < 0.001) in intraoperative time, anxiety, and incidence of tooth fracture was confined to group I. The pain significantly reduced from the first to the third postoperative day in both groups, but the mean reduction in RMS scores in the physics forceps group was far better than that in the conventional forceps group. Conclusion: Physics Forceps aid in extraction of primary teeth with minimal trauma to supporting structures, as well as reducing anxiety in the pediatric population.

• Steel and Composite Structures
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• 제46권4호
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• pp.577-589
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• 2023

In this study, on-site testing was carried out to investigate the vibration performance of a cold-formed thin-walled steel floor system. Ambient vibration, walking excitation (single and double persons), and impulsive excitation (heel-drop and jumping) were considered to capture the primary vibration parameters (natural frequencies, damping ratios, and mode shapes) and vertical acceleration response. Meanwhile, to discuss the influence of cement fiberboard on structural vibration, the primary vibration parameters were compared between the systems with and without the installation of cement fiberboard. Based on the experimental analysis, the cold-formed thin-walled steel floor possesses high frequency (> 10 Hz) and damping (> 2%); the installed cement fiberboard mainly increases the mass of floor system without effectively increasing the floor stiffness and may reduce the effects of primary vibration parameters on acceleration response; and the human-structure interaction should be considered when analyzing the vibration serviceability. The comparison of the experimental results with those in the AISC Design Guide indicates that the cold-formed thin-walled steel floor exhibits acceptable vibration serviceability. A crest factor 𝛽_rp (ratio of peak to root-mean-square accelerations) is proposed to determine the root-mean-square acceleration for convenience.

• 한국인구학
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• 제29권1호
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• pp.71-95
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• 2006

이 연구에서는 결혼 만족과 결혼 안정에 영향을 미치는 관련 변인들을 실증 분석하였으며, 특히 성에 대한 이중 기준이 결혼 만족과 결혼 안정의 관계에 어떤 영향을 미치는지에 분석의 초점을 두었다. 이 단계 군집표집에 의해 선정된 370명의 기혼 여성으로부터 수집된 자료를 다단계 다중회귀분석을 통해 분석하였다. 결혼 만족에 영향을 미치는 요인으로는 부부간의 상호소통, 친밀성, 성적 만족을 분석에 포함시켰으며, 결혼 안정에 영향을 미치는 요인으로는 조사 대상자의 경제활동 여부, 가구 소득 수준 결혼 만족을 분석에 포함시켰다. 그리고 성에 대한 일반적 태도를 바탕으로 조사 대상자를 성에 대한 단일 기준 집단과 이중 기준 집단으로 나누었다. 분석의 결과는 부부간의 상호 소통과 친밀성은 결혼 만족에 영향을 미치나, 성적 만족은 결혼 만족과 관계가 없음을 보여 주고 있다. 그리고 결혼 만족과 결혼 안정은 매우 높은 관계를 보이고 있는데, 성에 대한 이중 기준이 결혼 만족과 결혼 안정의 관계 수준을 약화시키는 것으로 나타났다.

• 구강회복응용과학지
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• 제34권4호
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• pp.317-323
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• 2018

구강암이 상악에 발생하게 되면 원발 부위의 제거를 포함한 외과적 처치 후 비구강 개통(oro-nasal communication)이 발생하게 된다. 비구강 개통으로 인한 음식물의 저류를 막고 및 원할한 발음 및 심미적 회복을 위해서는 구강 폐색장치(Obturator)를 통한 수복이 필요하다.본 증례에서는 구강암으로 인해 우측 상악 편측절제술(hemi-maxillectomy) 시행하고 두경부 방사선 치료의 영향으로 인해 잔존 지대치의 우식과 불량한 치주지지를 보이는 환자에서 구강폐색장치(obturator)를 하이브리드형 이중관의치(hybrid telescopic double crown denture)로 수복하였다. 18개월 간 경과관찰에서 성공적인 예후를 보여 이를 보고하고자 한다.

• Tuberculosis and Respiratory Diseases
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• 제85권1호
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• pp.25-36
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• 2022

Background: Only a few studies directly compared the therapeutic efficacy and safety of two pressurized metered-dose inhalers (pMDIs) in asthma. We analyzed the asthma treatment outcomes, safety, and patient preferences using formoterol/beclomethasone (FORM/BDP), a pMDI with extra-fine particles, compared with formoterol/budesonide (FORM/BUD), another pMDI with non-extra-fine particles. Methods: In this randomized, double-blind, double-dummy parallel group study, 40 adult asthmatics were randomized to FORM/BDP group (n=18; active FORM/BDP and placebo FORM/BUD) or FORM/BUD group (n=22; active FORM/BUD and placebo FORM/BDP). During the two visits (baseline and end of 8-week treatment), subjects were asked to answer questionnaires including asthma control test (ACT), asthma control questionnaires (ACQ), and Quality of Life Questionnaire for Adult Korean Asthmatics (QLQAKA). Lung function, compliance with inhaler, and inhaler-handling skills were also assessed. Results: Ten subjects in the FORM/BDP group and 14 in the FORM/BUD group completed follow-up visits. ACT, ACQ, QLQAKA (a primary outcome), and adverse events did not differ between two groups. We found that the increase in forced expiratory volume in 1 second/forced vital capacity and forced expiratory flow at 25% to 75% of the pulmonary volume in the FORM/BDP group was higher than in the FORM/BUD group. Regarding preference, subjects responded that the flume velocity of FORM/BDP was higher, but more adequate than that of FORM/BUD. They also answered that FORM/BDP reached the trachea and bronchus and irritated them significantly more than FORM/BUD. Conclusion: The use of pMDI with extra-fine particles may relieve small airway obstruction more than the one with non-extra-fine particles despite no significant differences in overall treatment outcomes. Some asthmatics have a misconception about the adequacy of high flume velocity of pMDIs.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권4호
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• pp.308-315
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• 2004

Aim: The aim of this study was to investigate the mechanism of promoted skin wound healing in skin defects with primary cultured oral mucosal keratinocytes. Materials and methods: Thirty adult female nude mice weighing $20{\pm}2g$ were used for the experiment. Primary cultured and suspended oral mucosal keratinocytes, labeled with BrdU, were scattered onto $1.5cm{\times}1.5cm$ sized full thickness skin defects in the experimental group(N=15), and no grafts were placed the control group(N=15). They were sacrificed at 3 days, 1 week and 2 weeks after the treatment respectively. Histological examination of each wounds were performed to review the healing progress on measuring the length from the wound margin to regenerating epithelial front. The role of keratinocytes were assessed by double immunohistochemical staining with Anti-BrdU and Anti-cytokeratin AE1/3. Results: In the experimental group the wound was completely covered with regenerating epithelia in 2 weeks, but partially regenerated in the control group. The immunohistochemical studies unexpectedly reveal that most of regenerating epithelial cells were induced from marginal epithelium of the margin, not from the scattered keratinocytes. Conclusion: We could successfully confirm that graft of primary cultured oral mucosal keratinocytes promotes the regeneration of skin defects.