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The purpose of our research is creating a new nanocomposite material. Generally silk fibroin (SF) is regarded as a promising base material for biomedical uses. The incorporation of montmorillonite (MMT) into SF fibers would improve physical properties of the SF fibers. We investigated a new method of combining electospun SF with MMT. Specifically, electrospun silk nanofibers were treated with methanol and dipped in a MMT suspension. We could obtain a nanosheet composite of silk nanofibers and MMT. Their ultrastructures were successfully visualized by high resolution transmission electron microscopy. This compound was comprised of individual silk nanofibers surrounded by thin layers of MMT, each with a thickness of about 1.2 nm. This structure was confirmed by elemental analysis. We also performed IR, NMR and X-ray diffraction analyses in conjunction with morphological data. Conclusively we obtained a new composite of silk nanofiber and MMT, which has never been reported. Using this unique nanocomposite biological tests of its application for a scaffold for tissue engineering are under way., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Objectives: The purpose of this study is to evaluate the effects of multiple firings on the mechanical properties and microstructure of veneering ceramics used with zirconia frameworks., Methods: Five different veneering ceramics for zirconia frameworks were used: Vintage ZR (ZR), Cerabien ZR (CZR), Vita VM9 (VM9), Cercon ceram KISS (KISS), IPS e.max ceram (e.max), and one veneering ceramic used for PFM frameworks: Vintage MP (MP). Twenty specimens were fabricated of each veneering ceramic. Ten specimens were fired twice and another ten specimens were fired ten times. Three-point flexural strength following the ISO 6872 and Vickers hardness were measured, and fracture toughness (K(IC)) was calculated. Density and porosity were determined. Specimens were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM)., Results: For all materials, density increased and porosity decreased after 10 firings. Significant differences in density and porosity were observed between 2 and 10 firings, with the exception of VM9 (P<0.05). There were no significant differences in flexural strength between 2 and 10 firings except for MP. The Vickers hardness of ZR, VM9, KISS and MP increased significantly after 10 firings (P<0.001). There were no significant differences in fracture toughness for ZR, CZR, VM9 and MP between 2 and 10 firings. However, e.max underwent a significant increase in fracture toughness (P=0.000), and there was a significant decrease in the toughness of KISS after 10 firings (P=0.007)., Conclusion: Multiple firings could be effective for improving the densification and the hardness of veneering ceramics for zirconia restorations., Clinical Significance: By 10 firings, the density and hardness of the veneering ceramics used with zirconia frameworks were raised, and porosity was reduced. However, no significant changes occurred in flexural strength, fracture toughness or microstructure., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The complete amino acid sequence of the respective [2Fe-2S] ferredoxins from two varieties of Datura stramonium, D. stramonium var. stramonium and D. stramonium var. tatula, have been determined by automated Edman degradation of the entire Cm-protein and of the peptides obtained by tryptic digestion and CNBr treatment. The ferredoxins from the two plants exhibited identical amino acid sequences, suggesting a very close taxonomic relationship between the two. This result supports the proposal by Blakeslee and others that these plants, at first named by Linnaeus as two distinct species, i.e. D. stramonium L. and D. tatula L., should be considered two varieties of a single species.

OK-432, a killed preparation of Streptococcus pyogenes, as well as bacillus Calmette-Guérin (BCG) and Corynebacterium parvum are all known to induce immune interferon (IFN gamma) in mice. To examine the mechanisms of IFN gamma induction by OK-432, DDI mice were sensitized with various doses of OK-432, either by a single injection of a 1-mg dose or repeated injections of 0.1-mg doses given intraperitoneally. Spleen cells removed from the mice 7-9 days after the last injection produced high-titered IFN gamma (600-800 IU/ml) in vitro in the presence of 5 micrograms/ml of OK-432. In the absence of OK-432, however, in vitro IFN gamma production of sensitized spleen cells was quite limited. Moreover, when inducers of different antigenic entities such as serologically unrelated Streptococcus faecalis, Listeria monocytogenes, or Con A were added in vitro, instead of OK-432, to the OK-432-sensitized spleen cells, high-titered IFN gamma production also occurred. This may indicate that the signal required by T cells to produce IFN gamma in vitro need not necessarily be the same as that required to sensitize mouse macrophage in vivo. Once sensitized with OK-432, mice spleen cells continued to produce high-titered IFN gamma for more than 3 but less than 5 weeks.