18 research outputs found

    Surgical Treatment of Native Valve Aspergillus Endocarditis and Fungemic Vascular Complications

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    Systemic infection with Aspergillus is an opportunistic disease that affects mainly immunocompromised hosts, and is associated with a high mortality rate. It typically occurs in patients with several predisposing factors, but Aspergillus endocarditis of native valves is rare and experience in diagnosis and treatment is limited. We report a case of native valve endocarditis caused by Aspergillus. A 35-yr-old male patient who underwent pericardiocentesis four months previously for pericardial effusion of unknown etiology presented with right leg pain and absence of the right femoral artery pulse. Cardiac echocardiography revealed severe mitral insufficiency with large mobile vegetations, and computed tomographic angiography showed embolic occlusion of both common iliac arteries. We performed mitral valve replacement and thromoembolectomy, and Aspergillus was identified as the vegetation. We started intravenous amphotericin B and oral itraconazole, but systemic complications developed including superior mesenteric artery aneurysm and gastrointestinal bleeding. After aggressive management, the patient was discharged 78 days post surgery on oral itraconazole. He was well at 12 months post discharge but died in a traffic accident 13 months after discharge

    Post-transcriptional microRNA repression of PMP22 dose in severe Charcot-Marie-Tooth disease type 1

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    Copy number variation (CNV) may lead to pathological traits, and Charcot-Marie-Tooth disease type 1A (CMT1A), the commonest inherited peripheral neuropathy, is due to a genomic duplication encompassing the dosage-sensitive PMP22 gene. MicroRNAs act as repressors on post-transcriptional regulation of gene expression and in rodent models of CMT1A, overexpression of one such microRNA (miR-29a) has been shown to reduce the PMP22 transcript and protein level. Here we present genomic and functional evidence, for the first time in a human CNV-associated phenotype, of the 3' untranslated region (3'-UTR)-mediated role of microRNA repression on gene expression. The proband of the family presented with an early-onset, severe sensorimotor demyelinating neuropathy and harboured a novel de novo deletion in the PMP22 3'-UTR. The deletion is predicted to include the miR-29a seed binding site and transcript analysis of dermal myelinated nerve fibres using a novel platform, revealed a marked increase in PMP22 transcript levels. Functional evidence from Schwann cell lines harbouring the wildtype and mutant 3'-UTR showed significantly increased reporter assay activity in the latter which was not ameliorated by overexpression of a miR-29a mimic. This shows the importance of miR-29a in regulating PMP22 expression and opens an avenue for therapeutic drug development

    Removal of Chalk River unidentified deposit (CRUD) radioactive waste by enhanced electrokinetic process

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    Decontamination techniques proposed and used to remove Chalk River unidentified deposit (CRUD) in radioactive waste management. In cases of huge volumes of metal or radionuclides contaminated by CRUD, removal of CRUD by mechanical or chemical decontamination is difficult. An advanced electrokinetic process combined with chemical decontamination was applied to remove CRUD and experimentally evaluated. Oxalic acid was used for CRUD removal, and cobalt (Co) released from the CRUD was transferred to the cathode in an electrokinetic reactor. Results indicate that the combined system is efficient for CRUD removal with enhanced, efficiency by use of the cation exchange membrane and zeolite. (c) 2017 The Korean Society of Industrial and Engineering Chemistry.11Nsciescopuskc

    Fracture flow of radionuclides in unsaturated conditions at LILW Disposal Facility

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    Adsorption experiments for radionuclides such as 3H, 90Sr and 99Tc were conducted using fractured rock collected in unsaturated zone. The released radionuclide through artificial barrier from the near surface repository can be transported by the flow of rainfall or pore water through fractures in unsaturated zone and reach to groundwater flow. Therefore, it is important to investigate transport behavior (retardation) of radionuclides through fractured rock for the safety assessment and long-term performance of repository. Fractured rock samples were collected and characterized by X-ray microtomography (XMT) analysis, which can be used to develop a more robust unsaturated fracture transport model. When fracture-filling materials are exist, distribution coefficient of 90Sr is higher than without fracture-filling materials. In this study, batch sorption distribution coefficient (Kd) of radionuclide was determined and used to increase our understanding of radionuclide retardtion through fracture-filling materials.22Nkc

    Comparison between GlideRite® rigid stylet and Parker Flex-It™ stylet to facilitate GlideScope intubation in simulated difficult intubation: a randomized controlled study

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    Background The GlideScope® videolaryngoscope (GVL) is widely used in patients with difficult airways and provides a good glottic view. However, the acute angle of the blade can make insertion and advancement of an endotracheal tube (ETT) more difficult than direct laryngoscopy, and the use of a stylet is recommended. This randomized controlled trial compared Parker Flex-It™ stylet (PFS) with GlideRite® rigid stylet (GRS) to facilitate intubation with the GVL in simulated difficult intubations. Methods Fifty-four patients were randomly allocated to undergo GVL intubation using either GRS (GRS group) or PFS (PFS group). The total intubation time (TIT), 100-mm visual analog scale (VAS) for ease of intubation, success rate at the first attempt, use of laryngeal manipulation, tube advancement rate by assistant, and complications were recorded. Results There was no significant difference between the GRS and PFS groups regarding TIT (50.3 ± 12.0 s in the GRS group and 57.8 ± 18.8 s in the PFS group, P = 0.108). However, intubation was more difficult in the PFS group than in the GRS group according to VAS score (P = 0.011). Cases in which the ETT was advanced from the stylet by an assistant, were more frequent in the GRS group than in the PFS group (P = 0.002). The overall incidence of possible complications was not significantly different. Conclusions In patients with a simulated difficult airway, there was no difference in TIT using either the PFS or GRS. However, endotracheal intubation with PFS is more difficult to perform than GRS

    Interpretation of High-Temperature Tensile Properties by Thermodynamically Calculated Equilibrium Phase Diagrams of Heat-Resistant Austenitic Cast Steels

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    High-temperature tensile properties of three heat-resistant austenitic cast steels fabricated by varying W, Mo, and Al contents were interpreted by thermodynamically calculated equilibrium phase diagrams of austenite, ferrite, and carbides as well as microstructural analyses. A two-step calculation method was adopted to cast steel microstructures below the liquid dissolution temperature because the casting route was not an equilibrium state. Thermodynamically calculated fractions of equilibrium phases were well matched with experimentally measured fractions. Ferrites existed at room and high temperatures in both equilibrium phase diagrams and actual microstructures, which has not been reported in previous researches on austenitic cast steels. In the W2Mo1Al1 steel, 38% and 12% of ferrite existed in the equilibrium phase diagram and actual microstructure, respectively, and led to the void initiation and coalescence at ferrites and consequently to the serious deterioration of high-temperature strengths. The present equilibrium phase diagrams, besides detailed microstructural analyses, effectively evaluated the high-temperature performance by estimating high-temperature equilibrium phases, and provided an important idea on whether ferrite were formed or not in the heat-resistant austenitic cast steels.11sciescopuskc

    Effects of tungsten and molybdenum on high-temperature tensile properties of five heat-resistant austenitic stainless steels

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    Heat-resistant austenitic stainless steels have been intensively used worldwide for turbo-chargers requiring excellent high-temperature properties to sustain their structures at very high exhaust gas temperatures. Five heat-resistant austenitic stainless steels were fabricated by varying contents of W and Mo, and their high-temperature tensile properties were investigated by analyzing phases (liquid, austenite, ferrite, and carbides) existing at high temperatures. Effects of replacement of expensive alloying element, W, by Mo or reduction in W were also examined. The increase in contents of W and Mo resulted in linearly increased volume fractions of M7C3 and total carbides, while the volume fraction of MC carbide hardly showed any relation, and showed a good correspondence with high-temperature yield and tensile strengths. The steel where 2 wt% of W was replaced by 2 wt% of Mo showed the best 900 degrees C-tensile properties, thereby confirming the successful achievement of partly replacement of W by Mo. In addition, the low-W-containing steels showed excellent 900 degrees C-tensile properties, which also indicated that the reduction in 1-2 wt% of W was accepted for saving costs of alloying elements. (C) 2016 Elsevier B.V. All rights reserved.11sciescopu

    Effects of Mn and Mo addition on high-temperature tensile properties in high-Ni-containing austenitic cast steels used for turbo-charger application

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    Since turbo-chargers require more excellent high-temperature properties to maintain their structures at further higher exhaust gas temperatures up to 1050 degrees C, a 20 wt%-Ni-containing austenitic cast steel (N20 steel) has been suggested as a promising candidate cast steel. However, this steel is very expensive because it contains a large amount of expensive Ni. In order to partly replace expensive Ni by inexpensive Mn and to improve high temperature tensile properties in the N20 steel, three austenitic cast steels were fabricated by replacing 6 wt% of Ni by 6.9 wt% of Mn or by adding 2-4 wt% of Mo. Thermodynamically calculated fractions of equilibrium phases (austenite, ferrite, and M7C3 carbide) were matched with experimentally measured fractions, although they were somewhat overestimated. The N14 steel where 6 wt% Ni was replaced by 6.9 wt% of Mn did not contain any ferrite, and showed comparable or more excellent high-temperature tensile properties than those of the N20 steel, which indicated the successful replacement up to 6 wt% Ni by Mn, together with alloying cost reduction of 10%. The Mo addition also favorably affected high-temperature properties because Mo worked for increasing both M7C3 fraction and austenite matrix hardness. Simultaneously considering mechanical properties and alloying costs, therefore, these Mo-containing N14 steels can be fully adopted for high-performance turbo-chargers requiring excellent high-temperature properties.11sciescopu
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