Missense mutations of mitofusin 2 in axonal Charcot-Marie-Tooth neuropathy: polymorphic or incomplete penetration?

Khriezhanuo Nakhro,박진모,최병옥,정기화 한국통합생물학회 2013 Animal cells and systems Vol.17 No.4

Charcot-Marie-Tooth disease type 2A (CMT2A), which is caused by mutations in the Mitofusin 2 (MFN2) gene, is an axonal defective type of peripheral neuropathy. Over the years, mutations in the MFN2 have been reported to produce a wide range of phenotypes. This study endeavors to interrogate the phenomenon of penetrance and expressivity in MFN2 mutations for CMT2 families, showing both normal and disease phenotypes in mutant carriers within the same family. Exome sequencing was performed for four CMT2 families that showed three noncosegregating MFN2 missense mutations: p.R280H, p.R259H, and p.K98Q. The p.R280H mutation has been reported as disease causing by several studies, while two other mutations are unreported. Analysis of the exome data for more than 60 CMT-related genes did not produce other qualifying candidate mutations for the specific phenotypes. Commendable in silico scores were obtained, and control samples showed no mutation. The occurrence of incomplete penetrance has not been documented for MFN2 prior, but these families’ attributes and also the phenotypic heterogeneity reported over the years suggest the involvement of incomplete penetrance and variable expressivity in the MFN2 gene. Despite these predispositions, we also question if these variants are just very rare polymorphisms.

Low- and High-cycle Fatigue Behavior of Load-carrying Cruciform Joints with Incomplete Penetration and Strength Under-match

Takeshi Hanji,Kawin Saiprasertkit,Chitoshi Miki 한국강구조학회 2011 International Journal of Steel Structures Vol.11 No.4

The fatigue strengths of load-carrying cruciform joints with incomplete penetration and a strength mismatch between the base metal and the deposit metal were studied. Low- and high-cycle fatigue tests were performed on specimens with five matching conditions and two sizes of incomplete penetration. The test results revealed that the failure life was governed by crack propagation in both the low-cycle and high-cycle fatigue regions, and the crack propagation paths differed according to the matching and loading conditions. In addition, the fatigue strengths of the joints were compared for the degree of strength matching and the size of incomplete penetration in the low- and high-cycle fatigue regions. It was found that the effect of strength matching on the fatigue strength is negligible in the high-cycle fatigue region, but it becomes large in the low-cycle fatigue region and significantly reduces the fatigue life of the specimen in the under-matched joints.

교량의 피로강도를 고려한 맞대기용접부 불안전용입 한계결함 결정에 관한 연구

백영남,장영권 대한용접접합학회 2000 대한용접·접합학회지 Vol.18 No.3

The incomplete penetration(IP) discontinuity in butt joint weld, which is detected during safety analysis of the steel bridge by nondestructive evaluation(NDE) method, is classified as unacceptable defect according to the NDE codes and standards. In fact, there are a little allowance in butt joint weld in the view point of design criterion, and also detected IP discontinuity should be classified and evaluated for the fatigue strength and residual life estimation. In this study, we performed fatigue test to evaluate the fatigue strength of high strength steel(SWS490A) containing IP discontinuities in various size, the results compared and classified according to the bridge construction standard specification which published by korea administration of construction and traffic. Experimental results could be used to evaluate and estimate the IP discontinuities considering different stress range in butt joint bridge weld during periodic safety inspection.

용접부 배관의 Incomplete Penetration 결함 평가 사례 보고

이성식,김윤재,황춘옥 한국비파괴검사학회 2004 학술대회 논문집 Vol.- No.-

난방용 온수를 운반하는 배관의 시운전 과정에서 열 충격으로 인한 심한 변형이 발생하였다. 배관에서 결함의 발생 여부를 확인하기 위하여 비파괴검사(RT, UT, MT, PT)를 수행하였고, 배관 재료의 기계적 물성 변화를 확인하기 위해여 연속압입시험을 적용하였다. 방사선투과시험을 적용한 결과 배관에는 제작 시 발생한 불완전 용입(Incomplete Penetration) 결함이 배관의 거의 모든 용접부에 존재하고 있음이 새로이 발견되었다. 초음파시험으로 불완전 용입 결함의 깊이를 측정한 결과 불완전 용입 결함의 길이는 배관 원주의 2/3에 이르렀고 깊이는 두께의 60%에 이르렀다. 연속압입시험으로 기계적 물성을 측정한 결과 재료 물성의 변화는 크지 않았다. 불완전 용입부에서 파괴의 가능성과 균열의 발생 및 전파 가능성을 조사하기 위해 불완전 용입 결함을 날카로운 노치로 가정하고 사용적정성평가(Fitness For Service)를 수행한 결과 안전 계수를 고려하더라도 현재의 운전 조건 아래에서는 사용이 가능함을 확인하였다.

외력을 고려한 양면 T-용접이음부의 음력해석

김성환,방한서,방희선,송관형 대한용접접합학회 2001 대한용접·접합학회지 Vol.19 No.2

In the T-joint welding, the complete penetration joint which is obtained by groove welding with edge preparation is generally required thor the safety and reliability of structures but this way have the some defects such as increase of working time, consumed welding electrode quantity and large welding deformation. If there is no probrem, in the strength, T-joint welding without edge preparation will be profitably understood in the economical and welding deformation side. In this paper, we performed the finite element analysis to understand the characteristics of welding residual stresses on two models, complete penetration joint have the edge preparation and incomplete penetration joint without edge preparation, respectively. Especially, we observed the relation between welding residual stress distributed on the notch of gap in the root and external force in the incomplete penetration joint without edge preparation.

Fatigue life evaluation of socket welded pipe with incomplete penetration defect: I-test and FE analysis

Lee, Dong-Min,Kim, Seung-Jae,Lee, Hyun-Jae,Kim, Yun-Jae Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.11

This paper presents experimental and numerical analysis results regarding the effects of an incomplete penetration defect on the fatigue lives of socket welded pipes. For the experiment, four-point bending fatigue tests with various defect geometries (defect depth and circumferential length) were performed, and test results are presented in terms of stress-life data. The results showed that for circumferentially short defects, the fatigue life tends to increase with increasing crack depth, but for longer defects, the trend becomes the opposite. Finite element analysis showed that for short defects, the maximum principal stress decreases with increases in crack depth. For a longer defect, the opposite trend was found. Furthermore, the maximum principal stress tends to increase with an increase in defect length regardless of the defect depth.

강교량 맞대기용접 결함부의 피로수명 평가

백영남,장영권 대한용접접합학회 2000 대한용접·접합학회지 Vol.18 No.2

There are many weld defects such as surface crack, lack of fusion, and incomplete penetration (IP) in the butt joint weld of existing steel bridges. The crack-like defects may significantly reduce the fatigue life of the structure. This paper presents the procedure and the results of the fatigue life assessment of the butt joints with weld defects in the existing steel girder bridge. The butt joint welds with incomplete penetration were instrumented with strain gages to determine the stress histogram under normal traffic. Based on the measured stress histogram the crack propagation analysis were performed for the fatigue life assessment. By using the suggested procedure and methodology, one can decide the time of periodic inspection and the necessity of repair of the butt joint welds with serious weld defects in the existing steel bridge.

구조응력법을 이용한 소켓용접배관 피로수명평가기법

김승재(Seung Jae Kim),이현재(Hyun Jae Lee),김지수(Ji Su Kim),이동민(Dong Min Lee),김윤재(Yun Jae Kim) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.11

Small bore pipes of secondary system in power plant are socket welded for connection. During welding process, weld defect is formulated by incomplete penetration during welding. Due to these geometric discontinuity region, structural fatigue life of socket welded pipe can be affected. In this paper, to predict fatigue life of socket welded pipe considering defect, structural stress is applied to evaluate stress at geometric discontinuity region. Also, equivalent structural stress and master S-N curve, which are derived from fracture mechanics, are proposed as an evaluation.

20대 한국인에서 관찰되는 제2형 과립각막이상증의 다양한 표현형에 대한 고찰

서지형,류익희,홍진표,문자윤,최진석,전익현,김태임,김응권 대한안과학회 2022 대한안과학회지 Vol.63 No.12

목적: 제2형 과립각막이상증(granular corneal dystrophy type 2, GCD2)은 각막에 과립 및 격자형 침착물이 생기는 유전 질환으로, 동형접합자와 이형접합자가 있다. GCD2는 중심각막수술 후 악화되며, 이형접합자의 표현형에 개인차가 보고되는 바, 굴절수술이 잦은 국내 20대에서 관찰된 다양한 표현형을 조사하였다. 대상과 방법: 유전자(transforming growth factor β induced gene)검사 결과 R124H 변이가 발견되어 GCD2로 진단된 20대 환자 중동형접합자 1인, 복합이형접합자 1인, 단순 이형접합자임에도 과립형 참착물이 나이에 비하여 많은 1인, 보편적인 표현형의 이형접합자 1인, 각막에 초기 증상인 과립형 침착물이 보이지 않는 이형접합자 4인의 각막을 세극등현미경으로 관찰 및 촬영하였다. 결과: 동형접합자는 각막을 뒤덮는 융합성의 과립침착물을 보였다. 복합이형접합자의 경우 중심각막을 대부분 덮는 과립형과 격자형각막혼탁을 보였다. 단순 이형접합자임에도 단안에 30개 내외의 과립형 침착물이 존재하는 경우도 있었다. 투명각막으로 판정받았던이형접합자 4인 중에서 1인은 6개월 뒤 단안에 미세한 1개의 병변을, 1인은 3주 뒤 재검 시 단안에 매우 희미한 의심 병변 1개를 보였으며, 2인은 1회 조사 후에 투명각막으로 판정하였다. 결론: 20대의 GCD2 환자에서, 매우 혼탁한 각막부터 거의 투명한 경우까지 다양한 표현형이 나타남을 확인하였다. 병변 발견이 힘든GCD2 각막이 존재하므로 각막 중심부 수술 전 세심한 관찰과 검사가 필요하다.

필릿용접 루트부 Gap의 영향에 관한 연구

방한서,김성환,김종명 조선대학교 생산기술연구소 1998 生産技術硏究 Vol.20 No.2

The groove for proper welding joints is required to obtain a complete joint penetration However, fillet joint welding without edge preparation is often adopted to save coats and manhours. In this case, gaps of root may occurs, which cause stress concentration around gaps of root and compromises structural safety. In this paper, double fillet welded T-joints are selected for investigation. The welding residual stresses on the plate, web and notches of roots are calculated under two dimensional heat conduction and plane deformation thermal elasto-plastic theory are applied. It is found that multi pass welding alleviates stress concentration on the notch tips of roots by distributing the compressed residual stresses and external tensile forces in the direction of the width of web may restrict the occurrence of root-crack since the compressive residual stresses is expected in that direction. Through this results, in case of acting tensile force for the direction of the width of web, we supposed that occurrence of root-crack is restricted under the influence of compressed residual stress around notch-tip of root.