Porcine enamel matrix derivative enhances the formation of reparative dentine and dentine bridges during wound healing of amputated rat molars

We examined the biological effects of porcine enamel matrix derivative (EMD; Emdogain) on the formation of reparative dentine and dentine bridges in rat molars after pulp amputation. The pulp chambers of upper molars of Wistar rats were perforated and the amputated pulp surfaces were directly capped with either EMD or its carrier propylene glycol alginate (PGA) as control. The cavities were then restored with glass-ionomer cement. On post-amputation days 4-30, the dissected maxillae were examined by light and electron microscopy. In PGA-capped pulp, reparative dentine had been formed over the dentine walls under the prepared cavity on day 7 post-amputation and its thickness extended until day 30. On day 30, as well as reparative dentine formation, diffuse calcification had occurred beneath the amputated wound surfaces. Dentine bridge formation under the amputated coronal pulp surface was observed in 18.2% of amputated pulp on day 30. In EMD-capped pulp, reparative dentine had already been formed by odontoblast-like cells over the dentine walls, already on day 4 post-amputation, and its thickness extended until day 30. The Ca and P weight % and Ca/P ratio of reparative dentine matrix were similar to those of pre-existing dentine matrix, and these values were not different between PGA and EMD-capped pulp. Dentine bridge formation was observed in 27.3% of EMD-capped pulp on day 30. Our results suggest that EMD enhances the formation of both reparative dentine and dentine bridges during wound healing of amputated rat molar pulp.     

Osteoclast differentiation at growth plate cartilage-trabecular bone junction in newborn rat femur

Using 3-day-old newborn rats, we examined the differentiation processes of osteoclasts associated with the destruction of the femoral growth plate cartilage and primary trabecular bone. In the growth plate cartilage, thin mineralized areas were detected solely in the longitudinal septal cartilage matrix in the hypertrophic zone, but the transverse septal cartilage matrix between adjacent chondrocytic lacunae within a row of chondrocytes remained unmineralized. The longitudinal septal cartilage between adjacent rows of chondrocytes appeared to persist, forming the walls of opened lacunar canals. Consistent with the removal of the transverse septal cartilage matrix, the longitudinal canals of opened chondrocytic lacunae were deeply invaded by capillary vessels, mononuclear cells and multinucleated pre-osteoclasts lacking a ruffled border. CD34-positive endothelial cells of capillary vessels deeply penetrated into the transverse septal cartilage matrix facing the medullary cavity and the opened chondrocytic lacunae. ED1-positive monocytes/macrophages were distributed at the chondro-osseous junction, but they were distant from the erosive front of the transverse septa. Tartrate-resistant acid phosphatase-positive multinucleated pre-osteoclasts lacking a ruffled border and differentiated osteoclasts with a ruffled border were localized mainly at two locations: the chondro-osseous junction and the growth front of primary bone trabeculae. Osteoclasts were located on the type-I collagen-positive bone trabeculae close to the growth plate, but they appeared to be distant from the type-II collagen-positive cartilage matrix. Even within opened chondrocytic lacunae, when osteoclasts were distant from the cartilage and bone matrix, they lacked polarized cytoplasmic organization and a ruffled border. The osteoclasts located in the remaining septal cartilage also exhibited neither a ruffled border nor a clear zone. Osteoclasts with a prominent ruffled border and clear zone were located in bone matrix covering the remaining septal cartilage. These results suggest that osteoclasts require hydroxyapatite crystals and bone matrix constituents for ruffled border formation and are not involved in resorption of the unmineralized transverse and mineralized longitudinal septal cartilage without covering bone matrix at the chondro-osseous junction.     

Routing design of tree‐shaped local public communication networks with high reliability and low cost

This paper discusses reliability problems for local public communication networks such as cable television networks and the subscriber‐loops of telecommunication networks. They have tree‐shapes and expand continuously as new customers join. By introducing a simple model, it is shown that most principal reliability measures and cost measures for such networks can be described through the networks' graphical characteristic quantities. Extensive simulations show that the prior provision of trunk pipes and a suitable choice of the route selecting rule for new customers are effective in constructing a highly reliable network with low cost. This revised version was published online in June 2006 with corrections to the Cover Date.     

Free energy perturbation study on a Trp-binding mutant (Ser88 ->Cys) of the trp-repressor

The Ser⁸⁸Cys mutant of the trp-repressor showed a lower affinityfor the corepressor than the wild-type repressor [G = 1.7 ±0.3 kcal/mol, Chou and Matthews (1989) J. Biol. Chem., 264,18314–18319].A molecular dynamics/free energy cycle perturbation study wasperformed to understand the origin of the decreased affinity.A value (G = 1.58 ± 0.28 kcal/mol) comparable with theexperimental value was obtained by the simulation. Free energycomponent analysis revealed that destabilization of the vander Waals interaction between Ser⁸⁸ and Trp¹⁰⁹ (corepressor)mainly contributed to the decreased affinity of the mutant.The rotational transition of the hydroxyl (sulfhydryl) groupof Ser⁸⁸ (Cys⁸⁸) during the simulations affected the contributionsof Arg⁸⁴ and water to the free energy change in the aporepressorand those of Arg⁸⁴ and Trp ¹⁰⁹ to that in the holorepressor.However, the contributions from different residues compensatedeach other, and the total free energy changes were almost invariablein the various simulations.     

Matrix influence on the piezoelectric properties of piezoelectric ceramic/polymer composite exhibiting particle alignment

This study was addressed to the influence of an electric field strength applied at fabrication process and matrix properties, such as the dielectric constant and the Young's modulus, on “pseudo‐1‐3 piezoelectric ceramic/polymer composite” in order to further enhance the piezoelectricity of that. The pseudo‐1‐3 piezoelectric ceramic/polymer composite consists of linearly ordered piezoelectric ceramic particles in polymer material. Silicone gel, silicone rubber, urethane rubber, and poly‐methyl‐methacrylate, which exhibit different dielectric constants and Young's modulus, were used as matrices to evaluate the matrix influence. The piezoelectricity of the pseudo‐1‐3 piezoelectric ceramic/polymer composite was evaluated using the piezoelectric strain constant d₃₃. The d₃₃ is one of the indices of the piezoelectric properties for piezoelectric materials. As a result, it was confirmed that d₃₃ of the pseudo‐1‐3 piezoelectric ceramic/polymer composite increased with the increase of the electric filed strength applied at fabrication process, though, it reached a constant value at a certain strength value. Further it was confirmed that dielectric constant of the matrix had a small influence on d₃₃ of the pseudo‐1‐3 piezoelectric ceramic/polymer composite, however, in case of matrix of lower Young's modulus, d₃₃ was increase. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41817.     

Superior performance of non-activated multi-walled carbon nanotube polymer actuator containing ruthenium oxide over a single-walled carbon nanotube

The electrochemical and electromechanical properties of actuators developed using a non-activated multi-walled carbon nanotube (MWCNT)–ionic liquid (IL) gel electrode containing ruthenium oxide (RuO₂) were compared with only-MWCNT and only-single-walled carbon nanotube (SWCNT) based actuators. The double-layer capacitance of the non-activated MWCNT electrode containing RuO₂ was larger than that of the only-MWCNT electrode. The non-activated MWCNT polymer actuator containing RuO₂ surpassed the performance of the only-MWCNT and only-SWCNT actuators in terms of the strain and maximum generated stress. Both MWCNTs and RuO₂ were required to produce large strain and quick response actuators that surpassed the performance of the only-SWCNT polymer actuator and exhibited characteristics sufficient for practical applications (e.g. tactile display).     

Pressure drop characteristics of flow in a symmetric channel with periodically expanded grooves

Pressure drop characteristics of flow in a periodically grooved channel are investigated experimentally. It is well known that a self-sustained oscillatory flow occurs from a steady-state flow at a certain critical Reynolds number in such grooved channels. The oscillatory flow enhances fluid mixing and leads to an increase in pressure drop. We measure the pressure drop with a pressure transducer. It is found that the pressure drop increases near the critical Reynolds numbers where the two- and three-dimensional oscillatory flows occur. In addition, the three-dimensional flow is confirmed by flow visualization.     

开放式现场总线CC-Link在计量配料中的应用

本文主要介绍了利用开放式现场总线CC－Link来实现计量与配料的监控系统，达到可靠性，有效性，可维护性的目的，着重讨论了它们的特性，功能及其应用。     

Purification and characterization of a novel glutamyl aminopeptidase from chicken meat

A novel glutamyl aminopeptidase (aminopeptidase A, EC 3.4.11.7) was purified from chicken meat by ammonium sulfate fractionation, ethanol fractionation, heat treatment, and successive column chromatographies of DEAE-Sepharose CL-6B and Sephadex G-200. The purified enzyme migrated as a single band on SDS-PAGE. The molecular weight of this enzyme was found to be 55,000 and 550,000 by SDS-PAGE and Sephadex G-200 column chromatographies, respectively. This enzyme hydrolyzed Glu- and Asp-, but not Leu-, Arg-, and Ala-2-naphthylamide (-2NA) at all. The optimum pH and temperature for hydrolysis of Glu-2NA was 7.5. and 70°C, respectively. Reducing agents such as cysteine and dithiothreitol inhibited the activity of this enzyme at concentrations of 1 mM. However, the activation by Ca(2+) and the inhibition by amastatin were not observed.