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741.
Hiromichi Aono Hideyuki Hirazawa Tsunehiro Maehara Yuji Watanabe 《Materials Research Bulletin》2005,40(7):1126-1135
Nano-sized FeFe2O4 ferrite powder for local thermal coagulation therapy was synthesized by a reverse coprecipitation method. The crystal diameter for the samples from the reverse coprecipitation method was smaller than that from a normal coprecipitation method. The crystal diameter increased with an increase in the synthesized temperature for both methods. The maximum increasing temperature under the AC magnetic field was at around a 12 nm crystal diameter. The FeFe2O4 powder was oxidized to Fe2O3 by calcination at 600 °C in ambient air. The heating ability almost depended on the hysteresis loss value. Although the increased temperature under the AC magnetic field for the fresh FeFe2O4 sample was very close to that for the commercialized MgFe2O4 powder, it was gradually decreased for FeFe2O4 with time in ambient air. 相似文献
742.
Hideyuki Kanai Sunao Sugihara Hiroshi Yamaguchi Tomonori Uchimaru Naoyuki Obata Toshiyuki Kikuchi Fusaki Kimura Masato Ichinokura 《Journal of Materials Science》2007,42(23):9529-9535
The wetting and reaction between Si melt and SiO2 substrate were investigated as a function of the atmosphere, temperature, and degree of vacuum. The results revealed that
below 2 Torr with an Ar flow, the wetting angle is finally 90°. The Si droplet was stationary at a wetting angle of 90°. Videos
indicated that the droplets moved and vibrated; Above 20 Torr, the Si droplet vibrated up and down with a frequency of approximately
2 Hz, thereby changing the wetting angle. Further, the droplet remained stationary on a substrate on which grooves with a
width of 100 μm and depth of 100 μm were etched with a pitch of 1 mm. The presence of grooves or dimples on the substrates
facilitated the leakage of SiO gas; as a result, the Si droplet did not vibrate. A vibration model was proposed in which the
SiO gas produced at the interface between the Si droplet and the substrate according to the reaction Si + SiO = 2SiO expands
and leaks continuously. 相似文献
743.
Toita S Hasegawa U Koga H Sekiya I Muneta T Akiyoshi K 《Journal of nanoscience and nanotechnology》2008,8(5):2279-2285
Quantum dots (QDs) have attracted attention for their potential as a cell imaging regent. However, the development of effective intracellular delivery system for QDs is needed to apply various cell lines without affecting cellular function. We reported here new QDs delivery system by using cationic nanogel consisting of cholesterol-bearing pullulan modified with an amino group (CHPNH2). The uptake of hybrid nanoparticles into HeLa cells was followed by flow cytometry, and confocal laser scanning fluorescence microscopy. Protein-conjugated QDs were effectively internalized into cells by the nanogel compared with a cationic liposome system. The hybrid nanoparticle was used to stain rabbit mesenchymal stem cells (MSCs) so as to evaluate their effect on cell function. CHPNH2-QD hybrid nanoparticles remained detectable inside MSCs for at least 2 weeks of culture and had little effect on the in vitro chondrogenic ability of MSCs. The hybrid nanoparticles are a promising candidate as a cell tracer in tissue engineering. 相似文献
744.
Gravel riverbeds in the middle reaches of Japanese rivers are essential habitats for various plants and animals. Disturbance from flooding is necessary for the formation of gravel riverbeds, but human control of rivers, such as dams and channelization, has altered flow and sediment regimes, thereby reducing disturbance. The flooding generates a mosaic pattern characterized by varying frequencies and intensities of disturbance in gravel riverbeds. Understanding the disturbance regimes that form mosaic patterns is important for the conservation of biodiversity in rivers. In this study, we proposed a method to extract mosaic patterns from flow velocity regimes obtained by planar two-dimensional analysis by classifying them with time-series clustering. Based on the distribution of Anaphalis margaritacea var. yedoensis on gravel riverbanks, we compared several past flooding events to identify mosaic patterns that are important for A. margaritacea var. yedoensis. The study site is the Echi River, which flows through Shiga Prefecture in Japan and into Lake Biwa. Using a unmanned aerial vehicle (UAV), orthomosaic images with an average ground resolution of 3.3 mm/pixel were created, and colony polygons of A. margaritacea var. yedoensis were created using image detection and visual correction. Hydraulic analysis was performed using iRIC ver2.3 (Nays2DH ver1.0). Time-series clustering was used to classify the flow velocity regimes for each computed mesh into 30 clusters. The relationship between the clusters of each flooding event and the distribution of A. margaritacea var. yedoensis was evaluated. Mosaic patterns were created by classifying the flow velocity regimes of each computational mesh calculated by planar 2D analysis into clusters using time-series clustering. After analyzing the relationship between each cluster and the area of distribution of A. margaritacea var. yedoensis, the first flooding event was determined to be the mosaic pattern that best explained the distribution of A. margaritacea var. yedoensis. Cluster 1, the “low peak, short duration type,” was considered the growth center of A. margaritacea var. yedoensis. The method used in this study is an innovative approach for obtaining mosaic patterns that quantifies these five elements of the disturbance regime. 相似文献