Size-selective growth of double-walled carbon nanotube forests from engineered iron catalysts

We have succeeded in synthesizing vertically aligned doubled-walled carbon nanotube (DWNT) forests with heights of up to 2.2 mm by water-assisted chemical vapour deposition (CVD). We achieved 85% selectivity of DWNTs through a semi-empirical analysis of the relationships between the tube type and mean diameter and between the mean diameter and the film thickness of sputtered Fe, which was used here as a catalyst. Accordingly, catalysts were engineered for optimum DWNT selectivity by precisely controlling the Fe film thickness. The high efficiency of water-assisted CVD enabled the synthesis of nearly catalyst-free DWNT forests with a carbon purity of 99.95%, which could be templated into organized structures from lithographically patterned catalyst islands.     

Laser‐addressed full‐color photo‐quality rewritable sheets based on thermochromic systems with leuco dyes

We have developed a laser‐addressed full‐color photographic quality rewritable sheet. The sheet was composed of a vertically stacked Cyan/Magenta/Yellow‐thermochromic system with a mixture of leuco dyes, developers and photothermal conversion agents in a polymer matrix. The sheet was simply manufactured by roll‐to‐roll (R2R) processes. Writing and erasing were performed by scan of near‐infrared laser light. It achieved full‐color photographic quality images with a wide color gamut with 70% coverage of the Specifications for Web Offset Publications (SWOP) standards and a high resolution of 426 ppi. Clear rewritability has also been confirmed. Non‐contact laser writing has other advantages in that it can create an image under a protection film, and it has form factor flexibility. We have developed a reliability model for high‐temperature storage and a light fastness test. This model showed a good agreement with experimental data, and the lifetime of an image was estimated to be over 8 years under ambient conditions. This technology will create applications for on‐demand rewritable image design while saving power and reducing the use of paper, which will eventually contribute to a sustainable society.     

Organizing the Web's Information Explosion to Discover Unknown Unknowns

This paper introduces the TORISHIKI-KAI project, which aims to construct a million-word-scale semantic network from the Web using state of the art knowledge acquisition methods. The resulting network can be browsed as a Web search directory, and we show that the directory is useful for finding “unknown unknowns” — in the infamous words of D.H. Rumsfeld: things “we don't know we don't know.” Because typically we have no way to look for information we don't even know is missing, a crucial characteristic of unknown unknowns is that they are very difficult to discover through keyword-based Web search. Some examples of the unknown unknowns we have found include unexpected troubles associated with commercial products, surprising new combinations of ingredients in new recipes, unexpected tools or methods for commiting suicide, and so on. We expect such information to be useful for risk management, innovation support, and the detection of harmful information on the Web.     

Anti-Allergic Activity of Fucoidan Can Be Enhanced by Coexistence with Quercetin

In recent years, the incidence of type I hypersensitivity including hay fever has been increasing year by year in Japan. Our previous study using mice showed that only oral, but not intraperitoneal, administration of fucoidan extracted from seaweed (Saccharina japonica) suppressed type I hypersensitivity by secretion of galectin-9, which has a high affinity for IgE in the blood. However, the amount of seaweed required to achieve this activity is quite high (12 g dry weight per person per day). Therefore, the purpose of this study was to search for food ingredients in vegetables that enhance type I hypersensitivity suppression effect when consumed together with fucoidan. As a result, the enhanced effect was observed in extracts from Welsh onions and onions among vegetables. When we compared the polyphenols in the vegetables that showed activity with those that did not, flavonols such as quercetin and kaempferol were found as candidates. When quercetin or kaempferol (100 μg each) were orally administered at the same time, even at amounts where fucoidan alone showed no anti-allergic activity, anti-allergic effects were observed. More interestingly, when both flavonols were combined and administered simultaneously at half the amount of each of the above flavonols (50 μg), while the fucoidan amount remained the same, a similar effect was observed as when each flavonol (100 μg) was administered alone. The simultaneous intake of fucoidan and vegetables containing high contents of quercetin or kaempferol may reduce fucoidan intake while maintaining the allergy suppression effect, suggesting the importance of food combination.     

Targeting Folate Metabolism Is Selectively Cytotoxic to Glioma Stem Cells and Effectively Cooperates with Differentiation Therapy to Eliminate Tumor-Initiating Cells in Glioma Xenografts

Glioblastoma (GBM) is one of the deadliest of all human cancers. Developing therapies targeting GBM cancer stem cells or glioma stem cells (GSCs), which are deemed responsible for the malignancy of GBM due to their therapy resistance and tumor-initiating capacity, is considered key to improving the dismal prognosis of GBM patients. In this study, we found that folate antagonists, such as methotrexate (MTX) and pemetrexed, are selectively cytotoxic to GSCs, but not to their differentiated counterparts, normal fibroblasts, or neural stem cells in vitro, and that the high sensitivity of GCSs to anti-folates may be due to the increased expression of RFC-1/SLC19A1, the reduced folate carrier that transports MTX into cells, in GSCs. Of note, in an in vivo serial transplantation model, MTX alone failed to exhibit anti-GSC effects but promoted the anti-GSC effects of CEP1347, an inducer of GSC differentiation. This suggests that folate metabolism, which plays an essential role specifically in GSCs, is a promising target of anti-GSC therapy, and that the combination of cytotoxic and differentiation therapies may be a novel and promising approach to effectively eliminate cancer stem cells.     

HDAC Class I Inhibitor Domatinostat Preferentially Targets Glioma Stem Cells over Their Differentiated Progeny

Cancer stem cells (CSCs) are in general characterized by higher resistance to cell death and cancer therapies than non-stem differentiated cancer cells. However, we and others have recently revealed using glioma stem cells (GSCs) as a model that, unexpectedly, CSCs have specific vulnerabilities that make them more sensitive to certain drugs compared with their differentiated counterparts. We aimed in this study to discover novel drugs targeting such Achilles’ heels of GSCs as anti-GSC drug candidates to be used for the treatment of glioblastoma, the most therapy-resistant form of brain tumors. Here we report that domatinostat (4SC-202), a class I HDAC inhibitor, is one such candidate. At concentrations where it showed no or minimal growth inhibitory effect on differentiated GSCs and normal cells, domatinostat effectively inhibited the growth of GSCs mainly by inducing apoptosis. Furthermore, GSCs that survived domatinostat treatment lost their self-renewal capacity. These results suggested that domatinostat is a unique drug that selectively eliminates GSCs not only physically by inducing cell death but also functionally by inhibiting their self-renewal. Our findings also imply that class I HDACs and/or LSD1, another target of domatinostat, may possibly have a specific role in the maintenance of GSCs and therefore could be an attractive target in the development of anti-GSC therapies.     

Distribution of Zinc,Copper, and Iron in the Tailings Dam of an Abandoned Mine in Shimokawa,Hokkaido, Japan

Mine Water and the Environment - This paper addresses the mechanism of acid mine drainage generation in tailings from an abandoned mine site and predicts the evolution of zinc (Zn), copper (Cu),...     

Preparation and characterization of complex gel of type I collagen and aluminosilicate containing imogolite nanofibers

Complex gel materials of Type I collagen and aluminosilicate containing imogolite nanofibers were prepared as opaque gel by mixing an acidic fine dispersion of aluminosilicate with an acidic solution of collagen. The product was stained blue by Coomassie Brilliant Blue (CBB), indicating that the gel contained collagen. A white sponge was obtained after lyophilization of the complex gel. Elemental analysis revealed that the complex contains C, H, N, Al, and Si atoms; and the compositional ratio of aluminosilicate/collagen (w/w) was calculated as 0.75 for the complex gel when aluminosilicate was mixed with an equal quantity of collagen. Transmission electron microscope (TEM) observation showed that aluminosilicate nanofibers were homogeneously distributed in the collagen matrix. The thermogravimetric analysis (TGA) curve of the complex was not a simple summation of each components, and especially, the weight loss step corresponding to detachment of the adsorbed water observed in aluminosilicate became difficult to distinguish, suggesting that the adsorbed water was removed in the complexation. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010