Promoting Effect of Basic Fibroblast Growth Factor in Synovial Mesenchymal Stem Cell-Based Cartilage Regeneration

Synovial mesenchymal stem cell (SMSC) is the promising cell source of cartilage regeneration but has several issues to overcome such as limited cell proliferation and heterogeneity of cartilage regeneration ability. Previous reports demonstrated that basic fibroblast growth factor (bFGF) can promote proliferation and cartilage differentiation potential of MSCs in vitro, although no reports show its beneficial effect in vivo. The purpose of this study is to investigate the promoting effect of bFGF on cartilage regeneration using human SMSC in vivo. SMSCs were cultured with or without bFGF in a growth medium, and 2 × 10⁵ cells were aggregated to form a synovial pellet. Synovial pellets were implanted into osteochondral defects induced in the femoral trochlea of severe combined immunodeficient mice, and histological evaluation was performed after eight weeks. The presence of implanted SMSCs was confirmed by the observation of human vimentin immunostaining-positive cells. Interestingly, broad lacunae structures and cartilage substrate stained by Safranin-O were observed only in the bFGF (+) group. The bFGF (+) group had significantly higher O’Driscoll scores in the cartilage repair than the bFGF (−) group. The addition of bFGF to SMSC growth culture may be a useful treatment option to promote cartilage regeneration in vivo.     

The Influence of location of balls and ball diameter difference in rolling bearings on the nonrepetitive runout (NRRO) of retainer revolution

The nonrepetitive runout (NRRO) value of retainer revolution is caused mainly by the diameter differences of balls mounted in a bearing. Additionally, when more than one ball has diameter difference, the NRRO value of retainer revolution is believed to vary with the location of balls. In this study, the authors theoretically analyzed the NRRO value of retainer revolution considering the diameter differences and location of balls mounted in a bearing. Consequently, it is clarified that the mean value of the retainer revolution component calculated in all locations of balls decreased with increasing number of balls in a rolling bearing.     

In-situ monitoring of ultrasonic attenuation during rotating bending fatigue of carbon steel with electromagnetic acoustic resonance

Using electromagnetic acoustic resonance (EMAR), we studied the evolution of the surface-shear-wave attenuation and phase velocity during rotating bending fatigue of a 0.45% C steel. In the EMAR method, we used a magnetostrictively-coupled electromagnetic acoustic transducer (EMAT) for the contactless measurements of the axial shear wave that is a surface-shear wave, propagating in a cylinder-specimen circumference direction with the axial polarization. The attenuation coefficient always showed sharp peaks around 90% of the fatigue life, independent of the fatigue-stress amplitude. In addition to the ultrasonic measurements, we made crack-growth observations using replicas and measured recovery of attenuation and velocity after stopping the cyclic loading just before and after the peak. From these results, we concluded that the evolution of the ultrasonic properties is caused by a drastic change in dislocation mobility being accompanied by the crack growth.     

Photocatalytic decomposition of NO on titanium oxide thin film photocatalysts prepared by an ionized cluster beam technique

Transparent TiO₂ thin film photocatalysts were prepared on transparent porous Vycor glass (PVG) by an ionized cluster beam (ICB) method. The UV‐VIS absorption spectra of these films show specific interference fringes, indicating that uniform and transparent TiO₂ thin films are formed. The results of XRD measurements indicate that these TiO₂ thin films consist of both anatase and rutile structures. UV light (λ > 270 nm) irradiation of these TiO₂ thin films in the presence of NO led to the photocatalytic decomposition of NO into N₂, O₂ and N₂O. The reactivity of these TiO₂ thin films for the photocatalytic decomposition of NO is strongly dependent on the film thickness, i.e., the thinner the TiO₂ thin films, the higher the reactivity. This revised version was published online in July 2006 with corrections to the Cover Date.     

Synthesis of Polyaniline/Pd Nanoparticles via Ligand Exchange

Polyaniline/Pd nanoparticles were synthesized via ligand exchange. Pre-prepared water soluble starch/Pd nanoparticles were treated with polyaniline, and washed with water, leading to the small and well-dispersed polyaniline/Pd nanoparticles. The redox state of polyaniline was preserved during the ligand exchange reaction.

Increased carbonyl protein levels in the stratum corneum of the face during winter

The stratum corneum (SC) is the interface between the body and the environment, and is continuously exposed to oxidative stress that results in carbonyl modification of proteins. We previously developed a simple and non-invasive method to assess the stratum corneum carbonyl protein (SCCP) levels. In this study, we used this method to examine the seasonal changes in the SCCP levels and the relationship between the SCCP level and the physiological condition of the SC. SC was collected from the face of healthy Japanese volunteers by adhesive tape stripping and its carbonyl groups were determined by reaction with fluorescein-5-thiosemicarbazide. The average fluorescence intensity of the SC was calculated as the SCCP level. The SCCP level in the cheek was higher in winter than summer. The SCCP level was negatively correlated with the water content in the SC measured by the conductance and capacitance, and also negatively correlated with the extensibility of the skin measured by a Cutometer, suggesting that the mechanical properties of the skin can be affected by oxidative modification of the SC. These data suggest the involvement of oxidative modification of SC proteins in the generation of rough skin during winter.     

Change in optical properties of stratum corneum induced by protein carbonylation in vitro

The skin is the frontier against the external environment and continuously exposed to the environmental oxidative stress such as ultraviolet (UV) irradiation. Protein carbonyls are the major oxidative products of protein and may be introduced by reaction with aldehydes derived from lipid peroxide. Acrolein is one of the most reactive aldehydes generated during degradation of lipid peroxides and protein-acrolein adducts have been found in the oxidatively damaged lesion including UV-damaged skin. Recent studies revealed that protein carbonyls are also detected in thin outermost layer of the skin, the stratum corneum (SC). However, the effect of protein carbonylation on the function of SC was still unclear. In this study, we treated the SC sheets of reconstructed human epidermis and porcine epidermis with acrolein in the experimental conditions to explore the influence of protein carbonylation on the SC. Human and porcine SC sheets treated with acrolein showed less transmission at visible light than untreated SC sheets. Attenuated total reflection-infrared spectroscopy with curve fitting analysis of amide I region showed that acrolein induced alterations in protein secondary structure of the porcine SC sheets, which were accompanied by diminished fibrous keratin structure observed by transmission electron microscopy. These results show the possibility that carbonylation of the SC caused by environmental factors is one of factors altering the fibrous structure of keratin and decreasing the light transmission of SC, which changes the quality of the skin appearance.     

Converting rice husk activated carbon into active material for capacitor using three-dimensional porous current collector

We have successfully applied rice husk activated carbon (RHAC) as an active material for the electric double layer capacitor using a three-dimensional (3D) porous current collector. The capacity and cycle stability were evaluated in a 1.0 mol dm⁻³ tetraethylammonium tetrafluoroborate/propylene carbonate solution in the range of 0-2.5 V. The specific capacity of the RHAC was about 14 mAh g⁻¹ at the 50 mA g⁻¹ discharge rate, corresponding to 19 F g⁻¹ under the present conditions. The RHAC cell using the 3D porous current collector possessed a lower internal resistance and better high-rate discharge properties than the RHAC cell using a conventional aluminum (Al) foil collector. After 5000 cycles of charging and discharging, the RHAC cell with the 3D current collector maintained 95% of its initial capacity, while the capacity of the one with the Al foil collector dropped to only 30%.     

Theoretical study of the hydrogen adsorption on AlB nanowire

We studied AlB nanowires as hydrogen storage materials based on density functional theory and Rigged QED theory. In this paper, we focused on the adsorption energy and the electronic structure of models. AlB nanowire models are compared with an Al nanowire model and AlB₂ crystal structure in terms of density of states, electron density, kinetic energy density, tension density and stress tensor density. These results revealed AlB nanowires do not have the conductivity, while the Al nanowire and AlB₂ bulk have it. It was also shown that the stabilization energies of AlB nanowires for the hydrogen adsorption are larger than that of Al nanowire. Adsorped hydrogens are more stable in the AlB nanowires than the Al nanowire.     

Effects of high pressure treatment on the flavour-related components in meat

This paper describes the effects of high-pressure treatment on the water-soluble components of meat responsible for the flavor of meat.

The amounts of peptides and amino acids as estimated by phenol reagent positive materials (PPM) apparently increased with increasing pressure applied to the muscle up to 300 MPa, but the differences between each treatment were not statistically significant. When the muscles were stored at 2°C for 7 days after the pressurization, increases in the amount of PPM were observed both in untreated and pressurized muscles. Apparently the contents of serine, glutamic acid, glutamine, glycine and alanine gradually increased in the extracts from pressurized muscle as the pressure increased up to 200 MPa, and some of them, especially glutamine and alanine, tended to decrease in the muscle pressurized at 300 MPa. When the muscles were stored for 7 days after the pressurization, apparent increases of the contents of aspartic acid, serine, proline, alanine and lysine were observed in the extracts both from untreated and pressurized muscles. However, significant differences were not observed in the contents of each amino acid between each treatment. The content of inosinic acid, which is considered to contribute to the ‘umani’ taste of the meat, was not reduced by the pressurization. High performance liquid chromatograph (HPLC) of soluble peptides revealed no significant changes in any fraction from the pressurized muscles up to 200 MPa and a significant decrease of the peptide fraction (approx. molecular weight 500) from the muscle pressurized at 300 and 400 MPa. When the muscles were stored after pressurization, significant increases in the peptide fraction of molecular weight 300 and the amino acid fraction, and a decrease of the peptide fraction of molecular weight 3000 were observed in the extracts both from the untreated and pressurized muscles.

From the results, it is suggested that high-pressure treatment on the post mortem muscle causes almost the same changes in the components responsible for the flavor of meat as those observed in conditioned muscle.