Fabrication of biofilm in nanoscale consisting of cytochrome f/2-MAA bilayer on Au surface for bioelectronic devices by self-assembly technique

We developed the nanoscale biofilm consisting of cytochrome f self-assembled on 2-MAA layer to apply bioelectronic devices. As cytochrome f has redox property, it can be possible to apply bioelectronic devices. The fabricated biofilm was confirmed by SPR and STM experiment. And the electrochemical property was checked by CV, CA, and STS.     

Characterization and stability of liposome-enveloped trypsin/Fe3O4 for drug delivery and drug release behavior

Liposome encapsulating Fe3O4 (liposome complexes) has been prepared for targeting a drug to a specific organ, as well as for MRI (magnetic resonance imaging) contrast agents. The objective of the present work was to investigate the Fe3O4 properties and the effects of chitosan concentration on the characteristics of chitosan-coated liposome complexes. They were characterized by DLS, FT-IR, XRD, VSM, UV-Vis spectrometer, TEM and phase-contrast microscopy. The average liposome complex size was approximately 500 nm, with individual Fe3O4 nanoparticle sizes of 10 nm. The drug incorporation efficiency of trypsin in liposome complexes was 65-69%, the drug release was sustained and the incorporated drugs had the magnetization properties of the liposome complexes. Incorporation of chitosan into the liposome bilayer decreased trypsin release from the liposome complexes due to an increased rigidity of the liposome membrane structure. Chitosan-coated liposome complexes showed a higher stability when compared with the stability of non-coated liposome complexes.     

Diet-induced changes in alginate- and laminaran-fermenting bacterial levels in the caecal contents of rats

Brown algae contain soluble polysaccharides, such as alginic acid, fucoidan and laminaran. To assess the induction of dietary fiber-fermenting bacteria in the intestine, rats were fed diet containing no dietary fiber (control) or 2% w/w of the polysaccharides for 2 weeks. The levels of dietary fiber-fermenting bacteria in caecal contents were determined using decimal dilution culture containing 1% w/v of the fibers. Caecal microbiota in the rats was analyzed using polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE). In the culture method, 4–9 log viable cells/g caecal content of alginate-fermenting bacteria was detected in rats fed alginate, while this was not detected in rats fed the control diet. Although laminaran-fermenting bacteria were detected in control rats (4–9 log viable cells/g), the level observed in rats fed laminaran was 8 or 9 log viable cells/g. On the other hand, fucoidan-fermenting bacteria were not detected in rats fed fucoidan. DGGE analysis showed laminaran administration increased the diversity of bacterial bands. Clostridium spp. and Parabacteroides distasonis were detected as typical species in rats fed alginate and laminaran. The results indicate that the intake of soluble fermentable fibers in edible brown algae can alter the intestinal microbiota and its fermentation capacity.     

The effects of slider design on thermal asperity rejection capability

Particle contamination has been an ongoing problem affecting the reliability of the magnetic hard disk drives. Especially the recent use of MR head requires much tighter control of particle contamination due to thermal asperity (TA) phenomenon. In this study, the effects of slider air bearing surface design on TA reduction capability were investigated by manufacturing two types of sliders. Numerical methods were used to simulate the motion of particles in the head/media interface. Experiments were conducted to verify the results predicted by the numerical simulation. Drives were built and exposed to particle contamination using a particle injection chamber, which turned out to be a very simple and reliable particle generation method over conventional aerosol technique. Then the number of TA generated in the drives was recorded and compared. Also the contacts between slider and particles were investigated by acoustic emission study. It was found that a new ABS design, which has aerodynamic U-shaped rail and central flow passage, was beneficial in reducing the particle contamination on the slider.     

Venom Peptide Toxins Targeting the Outer Pore Region of Transient Receptor Potential Vanilloid 1 in Pain: Implications for Analgesic Drug Development

The transient receptor potential vanilloid 1 (TRPV1) ion channel plays an important role in the peripheral nociceptive pathway. TRPV1 is a polymodal receptor that can be activated by multiple types of ligands and painful stimuli, such as noxious heat and protons, and contributes to various acute and chronic pain conditions. Therefore, TRPV1 is emerging as a novel therapeutic target for the treatment of various pain conditions. Notably, various peptides isolated from venomous animals potently and selectively control the activation and inhibition of TRPV1 by binding to its outer pore region. This review will focus on the mechanisms by which venom-derived peptides interact with this portion of TRPV1 to control receptor functions and how these mechanisms can drive the development of new types of analgesics.     

Machinability of Silicon Nitride/Boron Nitride Nanocomposites

The machinability and deformation mechanism of Si₃N₄/BN nanocomposites were investigated in the present work. The fracture strength of Si₃N₄/BN microcomposites remarkably decreased with increased hexagonal graphitic boron nitride ( h -BN) content, although machinability was somewhat improved. However, the nanocomposites fabricated using the chemical method simultaneously had high fracture strength and good machinability. Hertzian contact tests were performed to clarify the deformation behavior by mechanical shock. As a result of this test, the damage of the monolithic Si₃N₄ and Si₃N₄/BN microcomposites indicated a classical Hertzian cone fracture and many large cracks, whereas the damage observed in the nanocomposites appeared to be quasi-plastic deformation.     

Fe3O4@SiO2@TiO2@PDA Nanocomposite for the Degradation of Organic Materials

In order to enhance the effectiveness of pollutant removal by photocatalysis under visible light, a multifunctional photocatalyst was prepared by grafting polydopamine (PDA) with the core-shell nanocomposite Fe₃O₄@SiO₂@TiO₂ (FST). The structural, morphological, and magnetic responses of FST@PDA were characterized by X-ray diffraction pattern, Fourier transform infrared spectroscopy, transmission electron microscopy, etc. FST@PDA showed a high degradation rate of rhodamine B, reaching 98.7 % and 95.7 % after 150 min of ultraviolet and visible light radiation, respectively. In addition, the prepared FST@PDA had good safety and high recyclability due to the strong covalent bonds between FST and PDA.     

Morphology controlled 1D Pt nanostructures synthesized by galvanic displacement of Cu nanowires in chloroplatinic acid

One-dimensional platinum (Pt) nanostructures with different shape, size, and morphology were synthesized by galvanic displacement of sacrificial Cu nanowires in chloroplatinic acid baths. By increasing the concentration of H₂PtCl₆, the morphology of Pt nanostructures greatly altered from Pt nanoparticles decorated Cu nanowires, Pt coated Cu core-shell nanowires, dense Pt nanotubes to porous Pt nanotubes. At low concentration of H₂PtCl₆ (<1 mM), the Pt content monotonically increased with an increase in [H₂PtCl₆] (upto approx. 80 at.%). The Pt content became independent of [H₂PtCl₆] at higher concentration. The average external diameter and wall thickness of Pt nanotubes decreased with increasing [H₂PtCl₆] suggesting that the dissolution of copper is strongly dependent on [Cl⁻], which led to changes in the morphology of Pt nanostructures.     

Structure and magnetic properties of iron oxide dispersed silver based nanocluster composite

Magnetic nanocomposites composed of iron oxide and silver were fabricated by an inert gas condensation (IGC) method combined with co-evaporation, in situ oxidation, and in situ compaction techniques. The particle sizes of composite powder were controlled by varying helium gas pressure between 1 and 10 Torr, with the smallest one being about 10 nm at 1.0 Torr. The nanostructure of the composites was characterized by TEM. The magnetization behaviors were analyzed taking into account both the paramagnetic (PM) and ferromagnetic (FM) contributions to investigate the correlation between the nanostructure and the magnetic properties. It was found that some composites exhibit the superparamagnetism evidencing magnetically isolated grains as a single domain. TEM observation assisted with EDX revealed that iron nanocluster of a few nanometers size were surrounded by silver grains. Variation of the magnetic property of the nanocluster composites was also related to nanocluster size and heat treatment in an oxygen atmosphere.