Porphyromonas gingivalis Lipopolysaccharides Promote Proliferation and Migration of Human Vascular Smooth Muscle Cells through the MAPK/TLR4 Pathway

Atherosclerosis is a major cause of mortality worldwide. The initial change in atherosclerosis is intimal thickening due to muscle cell proliferation and migration. A correlation has been observed between periodontal disease and atherosclerosis. Here, we investigated the proliferation and migration of human aortic smooth muscle cells (HASMCs) using Porphyromonas gingivalis-derived LPS (Pg-LPS). To elucidate intracellular signaling, toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88) of HASMCs were knocked down, and the role of these molecules in Pg-LPS-stimulated proliferation and migration was examined. The role of mitogen-activated protein kinase (MAPK) in HASMC proliferation and migration was further elucidated by MAPK inhibition. Pg-LPS stimulation increased the proliferation and migration of HASMCs and activated the TLR4/MyD88 pathway. TLR4 knockdown inhibited Pg-LPS stimulated HASMCs proliferation and migration. Pg-LPS stimulation led to the phosphorylation of P38 MAPK, JNK, and ERK, and MyD88 knockdown inhibited the phosphorylation of P38 MAPK and JNK but not ERK. P38 MAPK and SAPK/JNK inhibition did not suppress the proliferation of HASMCs upon Pg-LPS stimulation, but ERK inhibition significantly inhibited proliferation. SAPK/JNK and ERK inhibition suppressed Pg-LPS-stimulated migration of HASMCs. In conclusion, our findings suggest that Pg-LPS may promote atherosclerosis via the activation of MAPK through TLR4.     

Computer experiment on propagation of solitons in crystals

Molecular dynamics computer simulation was carried out for homogeneous one-dimensional crystals and Langmuir–Blogett chain crystals. A mass-spring model was used, and the anharmonic interatomic potential up to the fourth order was taken into account. The total number of atoms was 120, and an end of the crystal was free to move and the other end fixed. An input pulse was applied to a couple of free end atoms, and the displacements and kinetic energies of all atoms in the crystal were computed. Solitons and phonons were produced, propagated and reflected at the ends of the crystal. Long-period propagation of stable solitons was observed in homogeneous crystals and in one-layer LB chain crystals.     

Density Measurement of Molten CaF2 by an Electrostatic Levitator

   High-quality single crystalline calcium fluoride (CaF₂) has been of considerable practical concern as an optical lens to an excimer laser stepper in the deep-ultraviolet region due to its excellent transparency. Highly accurate thermophysical properties of molten CaF₂ are essential as input data for a numerical simulation of the crystal growth process. The density of molten CaF₂ has been successfully determined in the stable and undercooled liquid states (1600–1820 K) with an electrostatic levitator. The temperature dependence of the density of molten CaF₂ is given by

Graphillion: software library for very large sets of labeled graphs

Several graph libraries have been developed in the past few decades, and they were basically designed to work with a few graphs. However, there are many problems in which we have to consider all subgraphs satisfying certain constraints on a given graph. Since the number of subgraphs can increase exponentially with the graph size, explicitly representing these sets is infeasible. Hence, libraries concerned with efficiently representing a single graph instance are not suitable for such problems. In this paper, we develop Graphillion, a software library for very large sets of (vertex-)labeled graphs, based on zero-suppressed binary decision diagrams. Graphillion is not based on a traditional representation of graphs. Instead, a graph set is simply regarded as a “set of edge sets” ignoring vertices, which allows us to employ powerful tools of a “family of sets” (a set of sets) and permits large graph sets to be handled efficiently. We also utilize advanced graph enumeration algorithms, which enable the simple family tools to understand the graph structure. Graphillion is implemented as a Python library to encourage easy development of its applications, without introducing significant performance overheads. In experiments, we consider two case studies, a puzzle solver and a power network optimizer, in which several operations and heavy optimization have to be performed over very large sets of constrained graphs (i.e., cycles or forests with complicated conditions). The results show that Graphillion allows us to manage a huge number of graphs with very low development effort.     

Cobalt‐containing smectite‐like mesoporous material as a new type of catalyst for hydrodesulfurization of thiophene

Cobalt‐containing mesoporous smectite‐like material (SM(Co)) was prepared by a hydrothermal method and used as a catalyst for hydrodesulfurization (HDS) of thiophene. It is active by itself and produces mainly butenes and a small amount of n-butane. When platinum is added to this material, the HDS activity is enhanced by 50%, while the product distribution does not change so much. The platinum‐loaded sample should have two types of active sites, one originally present in the smectite‐like material and the other with platinum, the latter being different in nature from a sample of platinum supported on silica gel. Thus, the SM(Co) and Pt/SM(Co) samples are new types of HDS catalysts. This revised version was published online in July 2006 with corrections to the Cover Date.     

In vitro synthesis of polyhydroxyalkanoate catalyzed by class II and III PHA synthases: a useful technique for surface coatings of a hydrophobic support with PHA

In vitro synthesis of polyhydroxyalkanoates (PHAs) on a hydrophobic support, i.e. highly oriented pyrolytic graphite (HOPG), was performed using class II PHA synthase (PhaC1_Pp) from Pseudomonas putida and class III PHA synthase (PhaEC_Av) from Allochromatium vinosum. Using PhaC1_Pp and 3‐hydroxyoctanoyl‐CoA, a poly(3‐hydroxyoctanoate) [P(3HO)] film was formed on the hydrophobic support with a thickness of a few nanometers, as revealed by atomic force microscopy (AFM). A poly(3‐hydroxybutyrate) [P(3HB)] film was also formed using PhaEC_Av and 3‐hydroxybutyryl‐CoA. AFM observations of the HOPG surface during P(3HB) film formation revealed that polymerized P(3HB) covered HOPG surface within the reaction time, resulting in the formation of a homogeneous ultra‐thin film. This method of ultra‐thin PHA film formation on a hydrophobic support may be applicable to the surface‐coating technique of materials with biodegradable, bioabsorbable, and biocompatible PHAs. Copyright © 2009 Society of Chemical Industry     

On the electric double-layer structure at carbon electrode/organic electrolyte solution interface analyzed by ac impedance and electrochemical quartz-crystal microbalance responses

ac impedance and electrochemical quartz crystal microbalance (EQCM) techniques have been applied to analyze the structure of electric double-layer formed at carbon/organic electrolyte solution interface using a sputtered carbon electrode. The mass changes caused by electrochemical adsorption (accumulation) of ions have been estimated in the solutions of propylene carbonate (PC) dissolving tetrafluoroborate (BF₄⁻) salts of lithium (Li⁺), tetraethylammonium (TEA⁺) and tetra-n-butylammonium (TBA⁺) cations. The observed mass changes during the cathodic polarization in the solutions containing TEA⁺ and TBA⁺ were well consistent with those expected by the calculation based on mono-layer adsorption of the cations with giving the consideration to the surface roughness. On the other hand, the mass change observed in the solution containing Li⁺ salt showed that the solvation of Li⁺ with three or four molecules of PC would be the charge compensation species at the interface. Comparison of the quantity of the electricity passed during the EQCM measurements with that from theoretical calculation with simple Helmholtz-layer model revealed that the major part of the double-layer capacitance would be based on the electrostatic polarization of the solvent molecule directly adsorbed at the carbon surface.     

Willow clones with high biomass yield in short rotation coppice in the southern region of Tohoku district (Japan)

The present study was conducted to select willow (Salix spp.) clones with a high potential for use as biomass energy crops in the southern region of Tohoku district in Japan. Cuttings of 8 willow clones were planted on an abandoned farmland near Sendai (av. annual temp., 10.9 °C) in March 2006, grown throughout the year and cut back in late December 2006 to resprout from the remaining stools in March 2007. The biomass yield in December 2007, after the first growing season, was highest in Salix pet-susu clone KKD, followed by Salix pseudolinearis clone FXM and Salix sachalinensis clone SEN. The biomass yield on December 2008, after the second growing season, was again highest in clone KKD followed by clone FXM, S. pet-susu clone HB471 and S. sachalinensis clone SEN; the average annual yield of dry mass after the second growing season being 3.09, 2.58, 2.17 and 1.85 kgDM plant^?1 for the clones in this order. Plant growth form differed among the clones. Clones FXM and SEN had several shoots of almost uniform base diameter, whereas clones KKD and HB471 showed plagiotropic growth with one thick and several thin shoots. The calorific values of dried stem segments were similar among clones, ranging from 18.7 to 19.1 kJ g^?1. The dried stem segments contained 78.9–81.2 wt.% hollocellulose, 27.2–32.3 wt.% lignin and 2.1–4.0 wt.% extractives with ethanol-benzene, depending on clones. Based on these results, we could select four clones (KKD, FXM, HB471 and SEN) suitable for biomass production by SRWC in this area.     

High‐frequency voltage oscillation in transformer windings and electrical breakdown properties of interturn insulation immersed in oil at VFT voltage

Switching operations in gas insulated switchgear (GIS) can generate very fast transient overvoltages (VFTO) which propagate in the GIS with little attenuation. When a transformer is directly connected to the GIS through a gas/oil bushing, the VFTO can enter the transformer and excite the voltage oscillation in the windings. In the paper, we firstly show a resonance phenomenon due to the superposition of the traveling waves which was found in the experiments using the coil windings of a 500 kV transformer. The fundamental resonance frequency ranged at about 2 MHz, and its voltage at the interturn (turn‐to‐turn) of the coil could reach 0.25 times of the applied voltage in the worst case. Secondly, the electrical breakdown properties of interturn insulation in oil were studied, applying the unipolar and bipolar voltages with 2 MHz oscillatory frequency. The breakdown voltages at the unipolar and bipolar VFT oscillatory stresses were about 1.25 and 1.40 times higher than that at the standard lighting impulse, respectively. We discuss the experimental breakdown stresses with the ones estimated from the analysis of VFTO in the transformer windings and also show the methods to cope with the VFTO. © 2000 Scripta Technica, Electr Eng Jpn, 132(4): 45–52, 2000