54 research outputs found

    In situ measurement of ultrasonic behavior during lap spot welding with laser ultrasonic method

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    Understanding the joining process in real time during welding can help improve welding quality, reliability, and manufacturing process efficiency. For this purpose, a laser ultrasonic method that can detect in situ welding quality without contact during welding would be useful. However, the behaviors of ultrasonic propagation as well as melting and joining with increasing temperature remain unclear. Therefore, this study aimed to experimentally investigate the in-process ultrasonic behavior when using the laser ultrasonic method. Lapped tungsten inert gas (TIG) arc spot welding was used for the ultrasonic measurements, wherein the ignition of the TIG arc from the specimen's top surface and laser irradiation for the ultrasonic measurement from the bottom surface occur simultaneously. In this welding, the melting width at the interface of the lapped plates is an important parameter. We investigated the type of ultrasonics used to measure the melting width and examined whether the melting behavior during welding could be experimentally captured. The results show that the ultrasonic velocity decreases as the temperature increases. The echo from the interface between the plates disappears, and the echo from the top surface appears. The disappearance and appearance of each echo facilitate the understanding of the melting behavior during welding

    A Quinolinone Compound Inhibiting the Oligomerization of Nucleoprotein of Influenza A Virus Prevents the Selection of Escape Mutants

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    The emergence of resistance to currently available anti-influenza drugs has heightened the need for antivirals with novel mechanisms of action. The influenza A virus (IAV) nucleoprotein (NP) is highly conserved and essential for the formation of viral ribonucleoprotein (vRNP), which serves as the template for replication and transcription. Recently, using in silico screening, we identified an antiviral compound designated NUD-1 (a 4-hydroxyquinolinone derivative) as a potential inhibitor of NP. In this study, we further analyzed the interaction between NUD-1 and NP and found that the compound interferes with the oligomerization of NP, which is required for vRNP formation, leading to the suppression of viral transcription, protein synthesis, and nuclear export of NP. We further assessed the selection of resistant variants by serially passaging a clinical isolate of the 2009 H1N1 pandemic influenza virus in the presence of NUD-1 or oseltamivir. NUD-1 did not select for resistant variants after nine passages, whereas oseltamivir selected for resistant variants after five passages. Our data demonstrate that NUD-1 interferes with the oligomerization of NP and less likely induces drug-resistant variants than oseltamivir; hence, it is a potential lead compound for the development of novel anti-influenza drugs

    Association of plasma thioredoxin-1 with renal tubular damage and cardiac prognosis in patients with chronic heart failure

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    AbstractBackgroundThioredoxin-1 (Trx-1) is an abundant 12.5kDa redox protein expressed in almost all eukaryotic cells that protect against the development of heart failure and kidney dysfunction. Plasma Trx-1 levels are considered as a reliable marker for oxidative stress. However, it remains to be determined whether plasma Trx-1 levels can predict cardiac prognosis in patients with chronic heart failure (CHF).Methods and resultsWe measured plasma Trx-1 levels and urinary β2-microglobulin–creatinine ratio (UBCR), a marker for renal tubular damage, in 156 consecutive patients with CHF and 17 control subjects. The patients were prospectively followed for a median follow-up period of 627 days and 46 cardiac events were observed. The patients with cardiac events had significantly higher plasma Trx-1 levels and UBCR levels than the cardiac event-free patients. Multivariate Cox proportional hazard analysis revealed that an elevated Trx-1 level was independently associated with poor outcome in patients with CHF after adjustment for confounding factors (hazard ratio, 1.74; 95% confidence interval, 1.33–2.29; p<0.0001). UBCR was increased with higher plasma Trx-1 levels. Kaplan–Meier analysis demonstrated that the highest Trx-1 tertile was associated with the highest risk of cardiac events.ConclusionPlasma Trx-1 level was associated with renal tubular damage and cardiac prognosis, suggesting that it could be a useful marker to identify patients at high risk for comorbid heart failure and renal tubular damage

    High-mobility group box 1-mediated heat shock protein beta 1 expression attenuates mitochondrial dysfunction and apoptosis

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    AbstractAimsApoptosis of cardiomyocytes is thought to account for doxorubicin cardiotoxicity as it contributes to loss of myocardial tissue and contractile dysfunction. Given that high-mobility group box 1 (HMGB1) is a nuclear DNA-binding protein capable of inhibiting apoptosis, we aimed to clarify the role of HMGB1 in heat shock protein beta 1 (HSPB1) expression during doxorubicin-induced cardiomyopathy.Methods and resultsMitochondrial damage, cardiomyocyte apoptosis, and cardiac dysfunction after doxorubicin administration were significantly attenuated in mice with cardiac-specific overexpression of HMGB1 (HMGB1-Tg) compared with wild type (WT) -mice. HSPB1 levels after doxorubicin administration were significantly higher in HMGB1-Tg mice than in WT mice. Transfection with HMGB1 increased the expression of HSPB1 at both the protein and mRNA levels, and HMGB1 inhibited mitochondrial dysfunction and apoptosis after exposure of cardiomyocytes to doxorubicin. HSPB1 silencing abrogated the inhibitory effect of HMGB1 on cardiomyocyte apoptosis. Doxorubicin increased the binding of HMGB1 to heat shock factor 2 and enhanced heat shock element promoter activity. Moreover, HMGB1 overexpression greatly enhanced heat shock element promoter activity. Silencing of heat shock factor 2 attenuated HMGB1-dependent HSPB1 expression and abrogated the ability of HMGB1 to suppress cleaved caspase-3 accumulation after doxorubicin stimulation.ConclusionsWe report the first in vivo and in vitro evidence that cardiac HMGB1 increases HSPB1 expression and attenuates cardiomyocyte apoptosis associated with doxorubicin-induced cardiomyopathy. Cardiac HMGB1 increases HSPB1 expression in cardiomyocytes in a heat shock factor 2-dependent manner

    Cooperative Path Planning for Heterogeneous Agents

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    Cooperation among different vehicles is a promising concept for route planning of Mobility as a Service (MaaS). For instance, vehicle platooning on highways decreases fuel consumption because it reduces the air resistance and several trucks cooperate with each other when planning. Traditional platooning, however, cannot model cooperation among different types of vehicles because it assumes the homogeneity of vehicle types. We study a model that permits heterogeneous cooperation and discuss a route optimization problem under assumption that the heterogeneous cooperation benefits the objective function. We experimentally evaluate the formulation through using synthetic and real graphs based on a modern integer programming solver with various parameter settings, which are not tried in previous studies. We also compare the results by the solves with simple heuristic method developed in this paper and discuss the results to reveal the properties of the optimization problem with heterogeneous vehicle types

    Synthesis, Structure, and Characterization of In10-Containing Open-Wells–Dawson Polyoxometalate

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    We have successfully synthesized K17{[{KIn2(μ-OH)2}(α,α-Si2W18O66)]2[In6(μ-OH)13(H2O)8]}·35H2O (potassium salt of In10-open), an open-Wells–Dawson polyoxometalate (POM) containing ten indium metal atoms. This novel compound was characterized by X-ray crystallography, 29Si NMR, FTIR, complete elemental analysis, and TG/DTA. X-ray crystallography results for {[{KIn2(μ-OH)2}(α,α-Si2W18O66)]2[In6(μ-OH)13(H2O)8]}17− (In10-open) revealed two open-Wells–Dawson units containing two In3+ ions and a K+ ion, [{KIn2(μ-OH)2}(α,α-Si2W18O66)]11−, connected by an In6-hydroxide cluster moiety, [In6(μ-OH)13(H2O)8]5+. In10-open is the first example of an open-Wells–Dawson POM containing a fifth-period element. Moreover, to the best of our knowledge, it exhibits the highest nuclearity among the indium-containing POMs reported to date

    Bactericidal and virucidal mechanisms in the alkaline disinfection of compost using calcium lime and ash

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    In the present study, the bactericidal and virucidal mechanisms in the alkaline disinfection of compost with calcium lime and ash were investigated. Two indicator microorganisms, Escherichia coli and MS2 coliphage, were used as surrogates for enteric pathogens. The alkaline-treated compost with calcium oxide (CaO) or ash resulted primarily in damage to the outer membrane and enzyme activities of E. coli. The alkaline treatment of compost also led to the infectivity loss of the coliphage because of the partial capsid damage and RNA exteriorization due to a raised pH, which is proportional to the amount of alkaline agents added. These results indicate that the alkaline treatment of compost using calcium oxide and ash is effective and can contribute to the safe usage of compost from a mixing type dry toilet
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