The vibration damping appears as a macroscopic material property due to the energy dissipation caused by the plastic deformation of the microstructure in the material, but the detailed mechanism is ...still unknown. This study prepared a damping material based on natural rubber (NR) and investigated its deformation behavior with/without fiber-shaped particles using synchrotron X-ray computed tomography (CT). High-resolution submicron X-ray CT was performed to evaluate the local strain in the microstructure from feature points scattered inside the NR. When the strain distribution changed under stepwise tensile loading, the NR-alone material deformed uniformly at the microscale, whereas the fiber composite rubber deformed nonuniformly. Furthermore, the number and volume of voids increased significantly with the compounding of fiber particles, and their values continued to increase depending on the strain amplitude and the loss factor. Controlling of non-uniform local strain and void formation will enable the design of damping characteristics.
•Damping characteristics of natural rubber (NR) and NR-based composite damping material was Investigated.•Its deformation behavior at the microscale was examined using X-ray computed tomography (CT).•Compositing the NR with fiber particles caused nonuniform deformation.•Number and volume of voids increased with compounding of fiber particles.
Pancreatic adenocarcinoma is an aggressive human malignancy and is characterized by resistance to apoptosis. Recently, NADPH oxidase (Nox) 4-mediated generation of intracellular reactive oxygen ...species (ROS) was proposed to confer antiapoptotic activity and thus a growth advantage to pancreatic cancer cells. The signaling mechanism by which Nox4 transmits cell survival signals remains unclear. Here, we show that both a flavoprotein inhibitor, diphenylene iodonium (DPI), and small interfering RNAs designed to target Nox4 mRNA (siNox4RNAs) inhibited superoxide production in PANC-1 pancreatic cancer cells, and depletion of ROS by DPI or siNox4RNAs induced apoptosis. Parallely, DPI treatment and siNox4RNA transfection blocked activation of the cell survival kinase AKT by attenuating phosphorylation of AKT. Furthermore, AKT phosphorylation of apoptosis signal-regulating kinase 1 (ASK1) on Ser-83 was reduced by DPI and siNox4RNAs. When ASK1Ser83Ala (an AKT phosphorylation-defective ASK1 mutant) was introduced into PANC-1 cells, this mutant alone induced apoptosis. But, addition of DPI or co-transfection of siNox4RNA had no additive effect, indicating that the mutant can substitute for these reagents in apoptosis induction. Taken together, these findings suggest that ROS generated by Nox4, at least in part, transmit cell survival signals through the AKT-ASK1 pathway in pancreatic cancer cells and their depletion leads to apoptosis.
The 80% ethanol extracts of 5 purple-fleshed sweet potato cultivars were separated into 2 fractions, anthocyanins- and phenolic compounds-rich fractions, to clarify the contribution of these ...constituents to the radical-scavenging activity. The separation was accomplished with an ethyl acetate liquid/liquid extraction. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity in each fraction and the contributors varied according to the cultivars. The dominant DPPH radical-scavengers in “Ayamurasaki” and “Kyushu-132” were anthocyanins rather than phenolic compounds, while those in “Miyanou-36” and “Bise” were phenolic compounds, such as chlorogenic acid. Furthermore, the high-performance liquid chromatography analysis of anthocyanins showed that “Ayamurasaki” and “Kyushu-132” were rich in anthocyanins with peonidin aglycon, whereas “Miyanou-36,”“Bise,” and “Tanegashimamurasaki” contained cyanidin aglycon.
The difference of the three-dimensional morphology of eutectic Si particles has been investigated in Al-7mass%Si cast alloys changing trace P and Sr contents by means of synchrotron radiation ...nano-tomography with Zernike phase plate. Fibrous Si morphology aligning in the same direction is observed in Al-7mass%Si-2ppmP alloy. Si particles in Al-7mass%Si-8ppmP-42ppmSr are not only of a plate-like morphology but also a coral-like and a fibrous morphology. All of the Si particles have either a fibrous morphology or a coral-like morphology in Al-7mass%Si-9ppmP-277ppmSr. It is realized that a solidification sequence affected by trace P and Sr contents changes the three-dimensional morphology of Si particles.
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•Three-dimensional morphology of eutectic Si particles had been observed in Al-7%Si alloy.•Trace elements change the three-dimensional morphology of eutectic Si particles.•Trace Sr content brings branching of Si particles during solidification.
Toxoplasma is a common parasite worldwide that mainly affects the brain, lungs and eyes. Although toxoplasmic encephalitis is a lethal disease without treatment, past case reports show most patients ...with systemic lupus erythematosus who developed toxoplasmic encephalitis were misdiagnosed and treated as neuropsychiatric systemic lupus erythematosus, which led to unfavorable outcomes. We herein describe a case of disseminated toxoplasmosis affecting all the above organs with atypical symptoms, which developed with exacerbation of systemic lupus erythematosus. She had initially manifested with retinochoroiditis without vitritis, mild cognitive impairment and an isolated lung mass. These are completely different from the classic symptoms of toxoplasmosis that have been reported in patients with HIV infection and/or those after hematopoietic transplantation. Our case, together with previously reported cases, suggests the manifestation of toxoplasmosis that develops in systemic lupus erythematosus patients can be different from that seen in conventional cases and varies between individual patients. Our case highlights both the difficulty in and the importance of diagnosing toxoplasmosis in patients with systemic lupus erythematosus and provides helpful information to identify this rare, devastating, yet treatable disease.
Increased risk of developing systemic lupus erythematosus (SLE) has been reported in patients with Klinefelter syndrome. Here, we describe a 16-year-old Japanese patient with trisomy X (47,XXX) who ...developed mixed connective tissue disease (MCTD) and Sjögren’s syndrome. She had polyarthritis, edematous fingers with Raynaud’s phenomenon, sicca syndrome, interstitial lung disease, possible myositis, and was positive for anti-nuclear antibody, anti-nRNP antibody and rheumatoid factor. This is the first report in the literature of a case of MCTD with female polysomy X, which further supports the link between the presence of extra X chromosome(s) and the development of autoimmune diseases.
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