• Journal of Korean Society of Steel Construction
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• v.12 no.2 s.45
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• pp.143-150
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• 2000

Depending upon the combination of tolerances specified in the standards on bolt, nut and washer for high tension bolt sets, there arises center-to-center deviation between bolt and washer. This deviation nay cause loss of effective contact area between nut- and washer-faces, which leads to some dispersion of the torque coefficient K. By adapting circular arc surface instead of flat surface for the nut, it is shown through numerical analyses that the dispersion of the torque coefficient can be minimized. In this way, optimum radius of curvature of the nut bearing surface is proposed.

• Communications of Mathematical Education
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• v.9
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• pp.63-72
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• 1999

수학의 가장 기본적인 요소인 수 개념과 감각의 형성과정에서 자리값에 대한 이해는 필수적이다. 또한 자리 값의 개념을 지도하기 위해서는 수와 연산지도가 통합되어야 하며, 논리적 사고력을 신장의 한 요소인 계산 알고리즘이 유의미한 학습되기 위해서는 자리값에 대한 이해가 바탕이 되어야 한다. 수에 대한 개념적 지식이 불충분한 상태에서 양을 수치화 하거나 지필 위주로 계산 알고리즘을 기계적으로 적용함으로 해서 발생하는 수와 연산학습의 결손을 줄이기 위해 본 연구에서는 수 개념과 감각을 기르기 위해 자리값 지도 방안에 대해서 알아보고자 한다.

• Ceramist
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• v.7 no.1
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• pp.21-29
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• 2004

인류의 평균수명이 지속적으로 연장되고 삶의 질을 향상시키려는 욕구가 증가함에 따라 고급 의료기술에 관한 관심이 크게 증가하고 있다. 기존에는 치아가 결손되었을 때 브릿지라는 보철물이나 틀니를 사용하였으나 인접 치아 및 잇몸에 손상을 주는 부작용이 있었다. 최근 널리 보급되고 있는 임플란트 시술법은 결손된 치아 자리에 인공치아를 심는 방법으로서, 치아가 소실된 부분에 치아뿌리 모양의 임플란트를 매식하여 턱뼈에 고정시킨 후 여기에 크라운을 연결하여 보철을 완성한다.(중략)

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2009.03a
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• pp.27-29
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• 2009

견관절 전방 불안정성에서 관절와 및 상완골 결손이 동반된 경우 적절한 진단과 치료는 치료 결과에 직접적인 영향을 주므로 중요하다. 견관절 불안정성은 정적 및 동적 안정화 구조물의 손상으로 기인하며, 상완골 두감입 골절(Hill-Sachs 병변), 관절와 골절이나 전하방 관절와 가장자리의 소실 등 정상적인 관절의 해부학 구조물을 훼손시키는 골성 이상 소견이 동반되면 경우에 따라 견관절 불안정성에 영향을 끼칠 수 있다. 본 강좌에서는 견관절 전방 불안정성에서 동반된 관절와 및 상완골의 골 결손에 대하여 논하고자 한다.

• Korean Journal of Microbiology
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• v.27 no.1
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• pp.1-9
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• 1989

The locations of 5' ends as well as the splicing pattern of viral poly A(-) 19S RNA from monkey cells infected with SV40 were determined by a modification of primer extension method. The 5' end of this RNA mapped at the major cap site at nucleotide residue 325, used most frequently by SV40 late RNAs. The intron from nt.373 to nt.558 was removed as the ordinary cytoplasmic poly A(+) 19S RNA. The 3'end of this RNA was very heterogeneous and distributed over 1 kb upstream of polyadenylation site, as determined by S1 nuclease mapping. The reason for this normally initiated and spliced RNA to accumulate in the nucleus was investigated. In order to test whether the presence of unused 3' splice region on this RNA caused such subcellular distribution, cells were transfected with SV40 mutant KNA containing deletion around 3' splice site. The RNA deleted of 3' splice region accumulated mainly in the cytoplasm. This accumulation did not result from the increased stability of the RNA due to the deletion, since the wild type and mutant RNAs exhibited similar half lives after chase with actinomycin D. Therefore it is likely that the 19S spliced RNA is hindered from being transported into the cytoplasm due to some pre-splicing complexes formed at the unused 3' splice site.

• Journal of the Mineralogical Society of Korea
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• v.19 no.1 s.47
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• pp.15-29
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• 2006

Synthetic Mn-tourmalines (tsilaisite) were obtained by hydrothermal synthesis under the condition of 2 Kbar, $375{\sim}700^{\circ}C$, and 50 day-run-time with complete substitution of Mg in dravite by Mn (Mn%=0, 25, 50, 75, and 100%). They are all 6 samples containing Mn-tourmaline with some amounts of albite, spessartine, rhodocrosite, phlogopite etc, showing different synthetic condition of temperature and Mn composition. Synthetic Mn-tourmalines are of site deficiency in X-site ($0.53{\sim}0.68$) more than that of natural ones (approx. $0.2{\sim}0.3$) and show Mn cations occupying Y-site less than expected with initial experiments, leading to failure in synthesis of end-member tsilaisite. Rietveld structural refinements reveal that $R_{wp}$ ($R_{p}/R_{exp}$) is in the range of 13.35 and 18.62%, $R_{B}$ and S (CofF) are $4.85{\sim}6.25%$ (S-18: 8.57%), $1.31{\sim}1.59$ (S-18: 1.81), respectively. Unit cell parameters (space group R3m, z=3) are ${\alpha}=15.8994\;{\AA}$ and $c=7.1846\;{\AA}$ in average (S-18: ${\alpha}=15.9491\;{\AA},\;c=7.1773\;{\AA}$). Average bond lengths of and are $2.67{\sim}2.69\;{\AA}$ (S-18: $2.65\;{\AA}$) and $2.00{\sim}2.02\;{\AA}$ (S-18: $1.96\;{\AA}$), respectively. Ditrigonality (${\delta}$) are in the range of 0.022 and 0.031 (S-18: 0.061), indicating degrading symmetry with increase of Mn content.

• Clinical and Experimental Pediatrics
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• v.51 no.4
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• pp.401-408
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• 2008

Purpose : Transcatheter closure of atrial septal defects (ASD) is currently established therapy as an alternative to surgery. But rarely, complications are reported in some studies. We report early and intermediate term complications associated with transcatheter closure of atrial septal defects using the Amplatzer septal occluder (ASO). Methods : From June 2003 to May 2006, 64 patients underwent transcatheter closure of secundum ASD or patent foramen ovale using the ASO. The ratio of male to female was 1:2.4, the median age was 17 years (range: 2.6-64 years) and their median weight was 47.5 kg (range: 2.6-64 kg). Results : The median diameter of ASD measured with transthoracic or transesophageal echocardiography was 15 mm (range: 6-28 mm), the median balloon stretched diameter was 18 mm (range: 6.5-34 mm), and the median size of device was 19.5 mm (range: 6-36 mm), was little difference with balloon stretched diameter. There were 10 cases of complications: arrhythmia (2), device malformation (2), aorta to right atrial fistula (1), hemolytic anemia (1), mitral valve encroachment (1), malposition (1), residual shunt (1), and inferior vena cava perforation (1). Conclusion : Transcatheter closure of ASD using ASO is effective and safe therapy. However, significant complications such as aorta to atrial fistula, atrial erosion, or device embolization can happen, so an appropriate selection of patient and device in relevance to size and anatomy of ASD is important for successful closure.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.3
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• pp.280-285
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• 2016

Mandible defects could be caused by congenital malformations, trauma, osteomyelitis, tumor resection. If large areas are included for reconstruction, those are primarily due to tumor resection defects. The large jaw defect results in a problem about mastication, swallowing, occlusion and phonetics, and poor esthetics causes a lot of inconvenience in daily life. It is almost impossible to be a part underwent mandibular resection completely reproduced, should be rebuilt artificially. This case is of a patient who was diagnosed with squamous cell carcinoma pT1N0M0, stage I in February 2004 and received surgery (combined mandibulectomy and neck dissection operation (COMMANDO) in oromaxillofacial surgery) in March 2004, by implant assisted removable partial denture. We could obtain good retention and stability through sufficient coverage and implant holding. Follow up period was about four years. Mandibular left third molar regions have been observed to have resorption of surrounding bone, and periodic check-ups are necessary conditions.

• Journal of the Korean Arthroscopy Society
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• v.13 no.2
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• pp.179-182
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• 2009

Purpose: Point fixation at the margin of the glenoid is a limitation of conventional arthroscopic stabilization using suture anchors, and does not afford sufficient footprint healing, especially in glenoid bone deficiency. So, we introduce an arthroscopic suture bridge transosseous-equivalent technique for bony Bankart lesions to avoid the technical disadvantage of point contact with anchor fixation and to improve mechanical stability through cross compression of the labrum. Surgical approach: The technique was adapted from the transosseous-equivalent rotator cuff repair technique using suture bridges, which improved the pressurized contact area and mean pressure between the tendon and footprint. After preparation of the glenoid bed by removal, reshaping, or mobilization of the bony lesion, two anchors (3.0 mm Biofastak, $Arthrex^{(R)}$, Naples, FL) were inserted into the superior and inferior portion of the bony Bankart lesion. Using a suture hook, medial mattress sutures were applied around the capsulolabral portion of the IGHL complex to obtain sufficient depth of glenoid coverage. A 3.5 mm pushloc anchor ($Arthrex^{(R)}$, Naples, FL) hole was made in the articular edge of the anterior glenoid rim. distal, suture bridge was applied, and proximal was inserted to mobilize the labrum in the proximal direction. This avoided the technical disadvantage of point contact with anchor fixation and decreased the level of gap formation through cross-compression of the labrum.

• Journal of the Korean Society of Radiology
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• v.5 no.1
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• pp.11-18
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• 2011

The periosteum contains multipotent cells that can differentiate into osteoblasts and chondrocytes. Cultured periosteum-derived cells (PDCs) have an osteogenic capacity. The purpose of this study was to evaluate the interaction of PDCs with bone graft biomaterial. After cell isolation from the calvarial periosteum of Sprague-Dawley rats, cultured PDCs were placed in critical-sized calvarial defects with beta-tricalcium phosphate (${\beta}$-TCP). All rats were sacrificed 8 weeks after bone graft surgery, and the bone regenerative ability of bone grafting sides was evaluated by plain radiography, micro-computed tomography (CT), and histological examination. PDCs grafted with ${\beta}$-TCP displayed enhanced calcification in the defect site, density of regenerated bone and new bone formation within the defect and its boundaries. Furthermore, these PDCs more efficiently regenerated new bone as compared to grafted ${\beta}$-TCP only. The results suggest that cultured PDCs have the potential to promote osteogenesis in bone defects.