• Title/Summary/Keyword: progressive failure

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Medeical Therapy For Pulmonary Arterial Hypertention (폐동맥고혈압에서 폐혈관계 작용약물)

  • Choi, Hye Sook;Lee, Sang Do
    • Tuberculosis and Respiratory Diseases
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    • v.60 no.2
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    • pp.142-150
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    • 2006
  • Pulmonary arterial hypertension (PAH) is often difficult to diagnose and challenging to treat. Untreated, it is characterized by a progressive increase in pulmonary vascular resistance leading to right ventricular failure and death. The past decade has seen remarkable improvements in therapy, driven largely by the conduct of randomized controlled trials. Still, the selection of most appropriate therapy is complex, and requires familiarity with the disease process, evidence from treatment trials, complicated drug delivery systems, dosing regimens, side effects, and complications. We tried to provide evidence-based treatment recommendations for physicians involved in the care of these complex patients. Due to the complexity of the diagnostic evaluation required, and the treatment options available, it is strongly recommended that consideration be given to referral of patients with PAH to a specialized center.

Characteristics Study by Pullout Test of Compression(JR-2000) Anchor (선단압축형(JR-2000) 앵커의 인발시험에 관한 특성연구)

  • Oh, Myung-Ju;Park, Tae-Young;Ha, Wook-Jai;Kim, Moon-Gyu
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.819-824
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    • 2005
  • Anchor system is widely used in construction works to support retaining structures. The compression anchor is characterized by excellent mechanism of pullout resistance, as well as less probability of progressive failure than a tension anchor. This paper presents the mechanical characteristics of a newly developed compression anchor(JR-2000). Field tests were performed to investigate characteristics of the pullout resistance of compression anchor.

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Genetics of Mitochondrial Myopathies

  • Shin, Jin-Hong;Kim, Dae-Seong
    • Journal of Genetic Medicine
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    • v.10 no.1
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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.

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

  • Yun, Tae-Jin;Kim, Yong-Jin
    • Journal of Chest Surgery
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    • v.25 no.12
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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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    • v.5 no.4
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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
    • Proceedings of the Korean Society of Veterinary Clinics Conference
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    • 2009.04a
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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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    • v.32 no.2
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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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    • v.7 no.5
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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.

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

  • Kang, Chul-Hoo;Oh, Jung Hwan;Song, Sook Keun;Kang, Sa-Yoon
    • Annals of Clinical Neurophysiology
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    • v.17 no.2
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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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    • v.54 no.6
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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.