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Medicine and, Japan

Tanaka M.,Kobe Pharmaceutical University | Hosotani A.,Kobe Pharmaceutical University | Tachibana Y.,Kobe Pharmaceutical University | Nakano M.,University of ToyamaToyama | And 3 more authors.
Langmuir | Year: 2015

Discoidal high-density lipoproteins generated by the apolipoprotein-mediated solubilization of membrane lipids in vivo can be reconstituted with phospholipids and apolipoproteins in vitro. Recently, it has been reported that such particles can be prepared using the hydrolyzed acid form of styrene-maleic anhydride copolymer (SMAaf) instead of apolipoproteins, but characterization of its physicochemical properties has remained less elucidated. In the present study, with the aim of applying SMAaf-based lipid nanoparticles as novel delivery vehicles of drugs and/or imaging agents, we investigated the preparation conditions and evaluated the physicochemical properties of lipid-SMAaf complexes. SMAaf induced spontaneous turbidity clearance of dimyristoylphosphatidylcholine (DMPC) vesicles accompanied by the formation of smaller particles not only at the phase transition temperature of DMPC but also above it. Such reductions in the turbidity were not observed with some other amphiphilic synthetic polymers tested under the same experimental conditions. Size exclusion chromatography analyses showed that homogeneously sized particles were prepared at lipid to SMAaf weight ratios of less than 1/1.5. Dynamic light scattering and transmission electron microscopy revealed that gel-filtered DMPC-SMAaf complexes were approximately 8-10 nm in diameter and discoidal in shape. The DMPC-SMAaf complexes were relatively stable even after lyophilization but were sensitive to pH changes. Fluorescence techniques demonstrated that the gel to liquid-crystalline phase transition temperature of DMPC in the discoidal complexes broadened significantly relative to that of liposomes, despite their common bilayer structure, which is a typical feature of discoidal lipid nanoparticles. These results provide fundamental insights into discoidal SMAaf-based lipid nanoparticles for the development of novel delivery vehicles. © 2015 American Chemical Society. Source

Sugiyama K.,Max Planck Institute for Plasma Physics (Garching) | Roth J.,Max Planck Institute for Plasma Physics (Garching) | Alimov V.Kh.,Max Planck Institute for Plasma Physics (Garching) | Alimov V.Kh.,University of ToyamaToyama | And 9 more authors.
Journal of Nuclear Materials | Year: 2015

Abstract Fe-W binary mixed layers were prepared as a model system for reduced-activation ferritic-martensitic (RAFM) steel for studying their dynamic erosion behavior resulting from energetic deuterium (D) irradiation. This investigation aims toward an assessment of RAFM steels as plasma-facing material. The surface composition of the model layers is modified by D irradiation. W is enriched at the surface with D irradiation fluence due to the preferential sputtering of Fe. It depends on the D impinging energy as well as the initial W fraction of the Fe-W layer. No significant development of surface topography was observed within the examined conditions. The erosion yield of a Fe-W layer is comparable to that of pure Fe in the low-fluence range and decreases with increasing D fluence. These results indicate that the dynamic change of erosion yield is significantly correlated with the surface W enrichment. © 2014 Elsevier B.V. Source

Jawaid P.,University of ToyamaToyama | Rehman M.U.,University of ToyamaToyama | Hassan M.A.,University of ToyamaToyama | Hassan M.A.,University of Sharjah | And 8 more authors.
Ultrasonics Sonochemistry | Year: 2016

In this study, we report on the potential use of platinum nanoparticles (Pt-NPs), a superoxide dismutase (SOD)/catalase mimetic antioxidant, in combination with 1 MHz ultrasound (US) at an intensity of 0.4 W/cm2, 10% duty factor, 100 Hz PRF, for 2 min. Apoptosis induction was assessed by DNA fragmentation assay, cell cycle analysis and Annexin V-FITC/PI staining. Cell killing was confirmed by cell counting and microscopic examination. The mitochondrial and Ca2+-dependent pathways were investigated. Caspase-8 expression and autophagy-related proteins were detected by spectrophotometry and western blot analysis, respectively. Intracellular reactive oxygen species (ROS) elevation was detected by flow cytometry, while extracellular free radical formation was assessed by electron paramagnetic resonance spin trapping spectrometry. The results showed that Pt-NPs exerted differential effects depending on their internalization. Pt-NPs functioned as potent free radical scavengers when added immediately before sonication while pre-treatment with Pt-NPs suppressed the induction of apoptosis as well as autophagy (AP), and resulted in enhanced cell killing. Dead cells displayed the features of pyknosis. The exact mode of cell death is still unclear. In conclusion, the results indicate that US-induced AP may contribute to cell survival post sonication. To our knowledge this is the first study to discuss autophagy as a pro-survival pathway in the context of US. The combination of Pt-NPs and US might be effective in cancer eradication. © 2015 Published by Elsevier B.V. Source

Taylor C.N.,Idaho National Laboratory | Shimada M.,Idaho National Laboratory | Merrill B.J.,Idaho National Laboratory | Akers D.W.,Idaho National Laboratory | Hatano Y.,University of ToyamaToyama
Journal of Nuclear Materials | Year: 2015

Abstract The present work is a continuation of a recent research to develop and optimize positron annihilation spectroscopy (PAS) for characterizing neutron-irradiated tungsten. Tungsten samples were exposed to neutrons in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory and damaged to 0.025 and 0.3 dpa. Subsequently, they were exposed to deuterium plasmas in the Tritium Plasma Experiment (TPE) at Idaho National Laboratory. The implanted deuterium was desorbed through sample heating to 900°C, and Doppler broadening (DB)-PAS was performed both before and after heating. Results show that deuterium impregnated tungsten is identified as having a smaller S-parameter. The S-parameter increases after deuterium desorption. Microstructural changes also occur during sample heating. These effects can be isolated from deuterium desorption by comparing the S-parameters from the deuterium-free back face with the deuterium-implanted front face. The application of using DB-PAS to examine deuterium retention in tungsten is examined. © 2014 Elsevier B.V. Source

Bobyr N.P.,NRC Kurcharov Institute | Alimov V.K.,Max Planck Institute for Plasma Physics (Garching) | Alimov V.K.,University of ToyamaToyama | Khripunov B.I.,NRC Kurcharov Institute | And 5 more authors.
Journal of Nuclear Materials | Year: 2015

Abstract Hydrogen isotopes exchange in tungsten was investigated after sequential exposures to low energy deuterium (D) and helium-seeded protium (He-seeded H) plasmas at sample temperatures of 403 and 533 K. Deuterium depth profiles were measured by the D(3He, p)4He nuclear reaction with 3He+ energies between 0.69 and 4.5 MeV allowing determination of the D concentration up to a depth of 8 μm. It was found that a significant part of the deuterium initially retained in tungsten after D plasma exposure was released during sequential exposure to a protium plasma. However, exposure of the D-plasma-exposed W samples to the He-seeded H plasma reduces the amount of released deuterium as compared to pure H plasma exposure. © 2014 Elsevier B.V. Source

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