• 제목/요약/키워드: progressive failure

검색결과 416건 처리시간 0.027초

Genetics of Mitochondrial Myopathies

  • Shin, Jin-Hong;Kim, Dae-Seong
    • Journal of Genetic Medicine
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    • 제10권1호
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    • pp.20-26
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    • 2013
  • Mitochondrion is an intracellular organelle with its own genome. Its function in cellular metabolism is indispensable that mitochondrial dysfunction gives rise to multisystemic failure. The manifestation is most prominent with tissues of high energy demand such as muscle and nerve. Mitochondrial myopathies occur not only by mutations in mitochondrial genome, but also by defects in nuclear genes or secondarily by toxic insult on mitochondrial replication. Currently curative treatment modality does not exist and symptomatic treatment remains mainstay. Administration of L-arginine holds great promise according to the recent reports. Advances in mitochondrial RNA import might enable a new therapeutic strategy.

심장외 도관을 사용하지 않는 동맥간의 완전교정;6례 보고 (Anatomic Correction of Truncus Arteriosus without a Extracardiac Conduit - Report of 6 cases -)

  • 윤태진;김용진
    • Journal of Chest Surgery
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    • 제25권12호
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    • pp.1448-1454
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    • 1992
  • Between July, 1990 and July, 1992, 6 male patients of truncus arteriosus, whose age ranged from 2 months to 18 months, underwent total surgical correction without a extracardiac conduit. Their anatomic types were type I in 3, type II in 2 and III, in one by the Collett-Edwards classification. Surgical techniques were similar to the first description by Lecompte except for the fact that distal pulmonary arterial stumps were approximated to ventriculotomy site without Lecompte maneuver in all cases. Also in all cases, mon-ocusps were placed using glutaraldehyde fixed autologous pericardial patch directly in right ventricular outflow tract. Three patients died postoperatively and the causes of death were myocardial failure, pulmonary hypertensive crisis and pulmonary complication due to progressive pulmonary vascualr obstructive disease respectively. The three survivors have been followed up for 6~10 months with good functional results.

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Diagnostic/prognostic health monitoring system and evaluation of a composite bridge

  • Mosallam, A.;Miraj, R.;Abdi, F.
    • Smart Structures and Systems
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    • 제5권4호
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    • pp.397-413
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    • 2009
  • Composite bridges offer many advantages compared to current steel and aluminum bridges. This paper presents the results of a comprehensive on-going research program to develop innovative Diagnostic Prognostic System (DPS) and a structural evaluation of Composite Army Bridge (CAB) system. The DPS is founded on three technologies: optical fiber sensing, remote data transmission, and virtual testing. In developing this system, both laboratory and virtual test were used in different damage scenarios. Health monitoring with DPS entailed comparing live strain data to archived strained data in various bridge locations. For field repairs, a family of composite chords was subjected to simple ramp loads in search of ultimate strength. As such, composite bridge specimens showcased their strengths, heralded the viability of virtual testing, highlighted the efficacy of field repair, and confirmed the merits of health monitoring.

Cardiomyopathies in small animals

  • Fujii, Yoko
    • 한국임상수의학회:학술대회논문집
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    • 한국임상수의학회 2009년도 춘계학술대회
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    • pp.127-133
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    • 2009
  • Cardiomyopathies were previously defined as "an idiopathic myocardial disease that is not secondary to any other type of congenital/acquired heart disease or systemic diseases." With increasing understanding of etiology and pathogenesis in human medicine, the difference between cardiomyopathy and specific heart muscle disease has become indistinct. Cardiomyopathies are now classified by the dominant pathophysiology or, if possible, by etiological/pathogenetic factors. The American Heart Association recently advocated the following new definition of cardiomyopathy: Cardiomyopathies are a heterogeneous group of diseases of the myocardium associated with mechanical and/or electrical dysfunction that usually (but not invariably) exhibit inappropriate ventricular hypertrophy or dilatation and are due to a variety of causes that frequently are genetic. Cardiomyopathies either are confined to the heart or are part of generalized systemic disorders, often leading to cardiovascular death or progressive heart failure-related disability. Because the understanding of etiology or pathogenesis of cardiomyopathy has been limited in veterinary medicine, the previous classification is generally used. It is considered a dilated, hypertrophic and restrictive group on the basis of the predominant morphological and functional abnormalities. In addition, arrhythmogenic right ventricular cardiomyopathy and unclassified cardiomyopathy were also recognized in dogs and/or cats.

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Modelling the dynamic response and failure modes of reinforced concrete structures subjected to blast and impact loading

  • Ngo, Tuan;Mendis, Priyan
    • Structural Engineering and Mechanics
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    • 제32권2호
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    • pp.269-282
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    • 2009
  • Responding to the threat of terrorist attacks around the world, numerous studies have been conducted to search for new methods of vulnerability assessment and protective technologies for critical infrastructure under extreme bomb blasts or high velocity impacts. In this paper, a two-dimensional behavioral rate dependent lattice model (RDLM) capable of analyzing reinforced concrete members subjected to blast and impact loading is presented. The model inherently takes into account several major influencing factors: the progressive cracking of concrete in tension, the inelastic response in compression, the yielding of reinforcing steel, and strain rate sensitivity of both concrete and steel. A computer code using the explicit algorithm was developed based on the proposed lattice model. The explicit code along with the proposed numerical model was validated using experimental test results from the Woomera blast trial.

Seismic behavior evaluation of exterior beam-column joints with headed or hooked bars using nonlinear finite element analysis

  • Rajagopal, S.;Prabavathy, S.;Kang, Thomas H.K.
    • Earthquakes and Structures
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    • 제7권5호
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    • pp.861-875
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    • 2014
  • This paper studies the response of seismic behavior of reinforced concrete exterior beam-column joints under reversal loading with different anchorages and joint core details. The joint core was detailed without much confinement (group-I) and/or with proposed X-cross bars in the core (group-II). The beam longitudinal reinforcement's anchorages were designed as per ACI 352 (headed bars), ACI 318 (conventional $90^{\circ}$ bent hooks) and IS 456 ($90^{\circ}$ bent hooks with extended tails). The nonlinear finite element analysis response of the beam-column joints was studied, along with initial and progressive cracks up to failure. The experimental and analytical results were compared and presented in this paper to make more scientific conclusions.

길랑-바레 증후군에서 발생한 Takotsubo 심근병 (Takotsubo Cardiomyopathy Associated with Guillain-Barré Syndrome)

  • 강철후;오정환;송숙근;강사윤
    • Annals of Clinical Neurophysiology
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    • 제17권2호
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    • pp.73-75
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    • 2015
  • A 69-year-old woman presented with a progressive limb weakness. Both clinical and neurophysiological findings were consistent with diagnosis of Guillain-$Barr{\acute{e}}$ syndrome (GBS). Two days after admission, the patient suffered from an acute coronary syndrome without stenosis at coronary arteriography. Echocardiography revealed left ventricular inferior wall and apical akinesia and decreased ejection fraction. A diagnosis of Takotsubo cardiomyopathy was then made. Left ventricular dysfunction and electrocardiography normalized within one month. Takotsubo cardiomyopathy can be developed as a complication of GBS.

Rebar corrosion effects on structural behavior of buildings

  • Yuksel, Isa
    • Structural Engineering and Mechanics
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    • 제54권6호
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    • pp.1111-1133
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    • 2015
  • Rebar corrosion in concrete is one of the main causes of reduction of service life of reinforced concrete buildings. This paper presents the influence of rebar corrosion on the structural behavior of reinforced concrete (RC) buildings subjected to strong earthquake ground motion. Different levels of rebar corrosion scenarios were applied on a typical four story RC frame. The deteriorated conditions as a result of these scenarios include loss in cross-sectional area and loss of mechanical properties of the reinforcement bars, loss in bond strength, and loss in concrete strength and its modulus of elasticity. Dynamic analyses of the frame with different corrosion scenarios are performed with selected strong earthquake ground motion records. The influences of degradation in both concrete and reinforcement on structural behavior are investigated by comparing the various parameters of the frame under different corrosion scenarios with respect to each other. The results show that the progressive deterioration of the frame due to rebar corrosion causes serious structural behavior changes such as change in failure mode. The intensity, propagation time, and extensity of rebar corrosion have very important effects on the level of degradation of steel and concrete, as well as on the earthquake behavior of the structure.

Wegener씨 육아종 (A Case of the Wegener's Granulomatosis)

  • 조정욱;황명순;윤치훈;이상도;김선우
    • 대한기관식도과학회:학술대회논문집
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    • 대한기관식도과학회 1981년도 제15차 학술대회연제순서 및 초록
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    • pp.13.4-13
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    • 1981
  • Wegener씨 육아종은 자가면역과 관련이 있다고 알려졌지만 아직껏 확실한 원인은 불명인 매우 드문 불치의 질환으로써 상기도 특히 비강이나 비인강에 괴사, 괴양성 병변 또는 괴저성 육아종 병변을 일으키며 더욱 진행되면 폐, 신장 및 혈관등을 침범하여 신사구체염과 전신적 괴저성 혈관염등 병변이 광범위하게 파급되며 조직학적 소견으로는 다핵 거대 세포가 보이는데 대개 6개월내에 사망한다. 병리 조직학적으로 확인된 Wegener씨 육아종 1례를 경험하였기에 문헌적 고찰과 아울려 보고하는 바이다.

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후천적 성인 편평족: 병태생리, 진단과 비수술적 치료 (Acquired Adult Flatfoot: Pathophysiology, Diagnosis, and Nonoperative Treatment)

  • 성기선;유인상
    • 대한족부족관절학회지
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    • 제18권3호
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    • pp.87-92
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    • 2014
  • Acquired adult flatfoot is a deformity characterized by a decreased medial longitudinal arch and a hindfoot valgus with or without forefoot abduction. The etiologies of this deformity include posterior tibial tendon dysfunction, rheumatoid arthritis, trauma, Charcot's joint, neurologic deficit, and damage to the medial spring ligament complex or plantar fascia. Among these, posterior tibial tendon dysfunction is the most well-known cause. Although posterior tibial tendon dysfunction has been regarded as a synonym of acquired adult acquired flatfoot, failure of the ligaments supporting the arch can also result in progressive deformity even without a posterior tibial tendon problem. The authors describe the pathophysiology, diagnosis, and nonoperative treatment of acquired adult flatfoot, focusing on posterior tibial tendon dysfunction.