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Haplodiploidy is a sex determination system in which fertilized diploid eggs develop into females and unfertilized haploid eggs develop into males. The evolutionary explanations for this phenomenon include the possibility that haplodiploidy can be reinforced by infection with endosymbiotic bacteria, such as Wolbachia. The subfamily Scolytinae contains species with haplodiploid and diploid sex determination systems. Thus, we studied the association with Wolbachia in 12 diploid and 11 haplodiploid scolytine beetles by analyzing wsp and multilocus sequence typing (MLST) of five loci in this endosymbiont. Wolbachia genotypes were compared with mitochondrial (COI) and nuclear (EF) genotypes in the scolytines. Eight of the 23 scolytine species were infected with Wolbachia, with haplodiploids at significantly higher rates than diploid species. Cloning and sequencing detected multiple infections with up to six Wolbachia strains in individual species. Phylogenetic analyses of wsp and five MLST genes revealed different Wolbachia strains in scolytines. Comparisons between the beetle and Wolbachia phylogenies revealed that closely related beetles were infected with genetically different Wolbachia strains. These results suggest the horizontal transmission of multiple Wolbachia strains between scolytines. We discuss these results in terms of the evolution of different sex determination systems in scolytine beetles.

Pyrroloquinoline quinone (PQQ) is a water-soluble quinone compound that has a strong anti-oxidant capacity. A previous study in rats fed a PQQ-depleted diet showed that elevated levels of serum triglyceride (TG) decreased after PQQ supplementation. However, there is only one study reporting the effects of PQQ on serum lipid levels, such as those of TG and cholesterol, in humans. In this study, the effects of PQQ disodium salt (BioPQQ™) on serum TG and cholesterol levels in humans after 6 and 12 wk of treatment at an oral dosage of 20 mg/d were examined. This trial was conducted according to a randomized, placebo-controlled, double-blinded protocol. A total of 29 healthy Japanese adults, ranging from 40 to 57 y old, with normal to moderately high TG levels (110-300 mg/dL) as measured by a recent blood examination, were included in this study. In eleven volunteers out of 29, serum low-density lipoprotein cholesterol (LDL-chol) levels at baseline were high (≥140 mg/dL). After 12 wk, the mean serum TG levels had not changed; however, a marginally significant decrease in the mean LDL-chol (from 136.1 to 127.0 mg/dL) was observed in the PQQ group. In the stratification analysis of the high LDL-chol subgroup (baseline LDL-chol level ≥140 mg/dL), the mean LDL-chol levels decreased significantly from the baseline values in the PQQ group compared to the placebo group. Our study findings suggest that PQQ suppressed the LDL-chol level, which is an important finding, because a high level of this lipid is a risk factor for various lifestyle-related diseases.

Ti­Fe­Cu alloys with higher Young’s modulus, hardness and compressive mechanical properties than those of the existing Ti alloys were developed using a d-electrons alloy design method in order to improve Young’s modulus, hardness and compressive properties of Ti and existing Ti alloys for use as metallic stents. Their microstructures, Young’s modulus, hardness and compressive mechanical properties were investigated both before (as-cast) and after heat-treatments performed under a high-purity argon atmosphere at 1173K for 21.6 and 86.4ks. The studied Ti­Fe­Cu alloys consist of the ¢-Ti phase and dendritic TiFe intermetallic phase. Moreover, the area fraction of the TiFe intermetallic phase increases with increasing atom ratio (Fe + Cu)/Ti of the alloys and with the heat-treatment time. The Young’s modulus of the studied Ti­Fe­Cu alloys increases from 110GPa (Ti78Fe18Cu4 alloy) to 145GPa (Ti68Fe30Cu2 alloy) with increasing atom ratio (Fe + Cu)/Ti of the alloys and the area fraction of the TiFe intermetallic phase. However, the Young’s modulus is saturated or slightly decreased when the area fraction of the TiFe intermetallic phase is more than 34%. The Vickers hardness of the as-cast alloys increases from 490HV (Ti78Fe18Cu4 alloy) to 550HV (Ti63.4Fe30Cu6.6 alloy) with increasing atom ratio (Fe + Cu)/Ti of the alloys and area fraction of the TiFe intermetallic phase. On the other hand, the Vickers hardness of the heat-treated alloys is lower than that of the as-cast alloys, despite the increase in the area fraction of the TiFe intermetallic phase after the heat-treatment. The heat-treated alloys have better compressive properties than those of the as-cast alloys and the reported Ti­Fe­Cu alloys. The compressive strength and strain of the heat-treated Ti67Fe27Cu6 alloys reach to 2131MPa and 24.5%, respectively. [doi:10.2320/matertrans.M2012361]

Haplodiploidy is a sex determination system in which fertilized diploid eggs develop into females and unfertilized haploid eggs develop into males. The evolutionary explanations for this phenomenon include the possibility that haplodiploidy can be reinforced by infection with endosymbiotic bacteria, such as Wolbachia. The subfamily Scolytinae contains species with haplodiploid and diploid sex determination systems. Thus, we studied the association with Wolbachia in 12 diploid and 11 haplodiploid scolytine beetles by analyzing wsp and multilocus sequence typing (MLST) of five loci in this endosymbiont. Wolbachia genotypes were compared with mitochondrial (COI) and nuclear (EF) genotypes in the scolytines. Eight of the 23 scolytine species were infected with Wolbachia, with haplodiploids at significantly higher rates than diploid species. Cloning and sequencing detected multiple infections with up to six Wolbachia strains in individual species. Phylogenetic analyses of wsp and five MLST genes revealed different Wolbachia strains in scolytines. Comparisons between the beetle and Wolbachia phylogenies revealed that closely related beetles were infected with genetically different Wolbachia strains. These results suggest the horizontal transmission of multiple Wolbachia strains between scolytines. We discuss these results in terms of the evolution of different sex determination systems in scolytine beetles.

Double-layered calcium phosphate coating films consisting of layers with different crystallinity and composition were fabricated on titanium substrates by RF magnetron sputtering. The first layer of the double-layered coating film, i.e., the inner layer, was made of calcium phosphate having high crystallinity, the second layer, i.e., the outer layer, was made of calcium phosphate having low crystallinity. A double-layered HAp/OAp coating film was fabricated on the titanium substrate; as an inner layer, an HAp film was prepared on the titanium substrate by heat treatment of an OAp film in air at 873 K for 7.2 ks, and then, the HAp layer was coated with the OAp film. In the fabrication of a double-layered OAp/ACP coating film, the inner OAp and the outer ACP films were coated on the titanium substrate under different sputtering conditions. The thickness of the single layer was controlled to be 0.5 μm, and the total thickness of these double-layered coating films was around 1 μm. The coating film that comprises the double-layer was dense with a uniform thickness, and the two layers were in close contact with each other. The bonding strength of the HAp/OAp coating film was greater than 50 MPa. As in vivo evaluation, the removal torque of HAp/OAp-coated titanium implants from the femur of Japanese white rabbits was measured. The value of this torque was considerably higher than that of the removal torque of non-coated titanium implants. The outer OAp layer with low crystallinity appeared to dissolve after the 4-week implantation, while the inner HAp layer remained intact and was directly attached to the new bone.

Wolbachia bacteria are among the most common endosymbionts in insects. In Wolbachia research, the Wolbachia surface protein (wsp) gene has been used as a phylogenetic tool, but relationships inferred by single-locus analysis can be unreliable because of the extensive genome recombination among Wolbachia strains. Therefore, a multilocus sequence typing (MLST) method for Wolbachia, which relies upon a set of five conserved genes, is recommended. In this study, we examined whether the alnus ambrosia beetle, Xylosandrus germanus (Blandford), is infected with Wolbachia using wsp and MLST genes. Wolbachia was detected from all tested specimens of X. germanus (n=120) by wsp amplification. Five distinct sequences (i.e. five alleles) for wsp were found, and labeled as wXge1–5. MLST analysis and molecular phylogeny of concatenated sequences of MLST genes identified wXge3 and wXge5 as closely-related strains. The detection rate of wXge4 and wXge1 was 100% and 63.3%, respectively; wXge2, wXge3 and wXge5 were detected from less than 15% of specimens. We performed mitochondrial haplotype analyses that identified three genetic types of X. germanus, i.e. Clades A, B and C. Wsp alleles wXge1, wXge2 and wXge4 were detected in all clade A beetles; wXge2 allele was absent from Clades B and C. We concluded that (i) five wsp alleles were found from X. germanus, (ii) use of MLST genes, rather than the wsp gene, are more suited to construct Wolbachia phylogenies and (iii) wsp alleles wXge2 and wXge3/wXge5 would infect clade A and clade B/C of X. germanus, respectively.

Calcium phosphate coating films were fabricated on blast-treated titanium plates and screw-type titanium implants using RF magnetron sputtering. A uniform and dense coating film with a thickness of 0.5 µm could cover the blast-treated titanium plate efficiently, maintaining the surface roughness of the substrates. The as-sputtered coating films consisted of amorphous calcium phosphate (ACP) or oxyapatite (Ca10(PO4)6O, OAp). Heat treatments of the OAp coating films were conducted in a silica ampoule or in air, and it was observed that the crystallinity of the coating films increased after the heat treatment. The bonding strength between the as-sputtered coating films, subjected to heat treatment in air, and the blast-treated titanium plates exceeded 60 MPa. An immersion test was conducted and alkaline phosphatase (ALP) activity of osteoblasts was investigated in vitro. The dissolution rate of the coating films in the 0.9% NaCl solution decreased with an increase in their crystallinity. The ACP coating film exhibited high ALP activity. As the in vivo evaluation, the coated and non-coated titanium implants were implanted into the femur of Japanese white rabbits. The percentage of bone-implant contact and the removal torque value of the coated titanium implants were greater than those of the non-coated titanium implants.

The adsorption characteristics of octapeptides, containing different numbers of aspartic acid, lysine, and alanine residues (i.e., D(4)K(0)A(4), D(4)K(1)A(3), D(4)K(3)A(1), D(4)K(4)A(0), and D(0)K(4)A(4)) on the surface of titanium (Ti) particles were investigated in the pH range of 3.0-8.8 at 30 degrees C. The adsorption isotherms for octapeptides having four plural aspartic acid residues with or without lysine residues showed two distinct adsorption modes, i.e., irreversible and reversible modes, at pHs 3.0-6.5; at pH 7.0 or higher, the adsorption mode was reversible. Increasing the number of lysine residues at a fixed number of aspartic acid residues (i.e., 4) decreased the amount of peptides adsorbed in both modes. D(4)K(4)A(0) adsorbed irreversibly at pHs 3.0-6.5, due to the fact that negatively charged carboxyl groups directly interact with a positively charged Ti surface, whereas positively charged amino groups of lysine residues are directed in an opposite direction toward the solution side, as predicted by molecular mechanics/dynamics calculations.

The role of the acidic amino acid residues in the adsorption of peptides/proteins onto stainless steel particles was investigated using a peptide fragment from bovine beta-lactoglobulin, Thr-Pro-Glu-Val-Asp-Asp-Glu-Ala-Leu-Glu-Lys (T5 peptide), which has a high affinity to a stainless steel surface at acidic pHs, and its mutant peptides substituted with different numbers of acidic amino acid residues. The adsorption behavior of the mutant peptides as well as the T5 peptide were studied at pH 3 with respect to concentration and ionic strength dependencies and the reversibility of the adsorption process. The behavior of the peptides was generally characterized as two distinct irreversible adsorption modes, Mode I and Mode II. In Mode I, the amounts adsorbed lay on the ordinate at zero equilibrium concentration in the solution, while in Mode II, the amount adsorbed increased with increased equilibrium concentration. The area occupied by the peptides was predicted by molecular mechanics and molecular dynamics. The state of the peptides, when adsorbed, was investigated using FT-IR analysis. The FT-IR analyses revealed that the side carboxylic groups of the peptides adsorbed on the stainless steel surface were ionized, while they were unionized in the solution at pH 3. Thus, the interactions between the carboxylic groups of the peptide and the stainless steel surface can be considered to be largely electrostatic. The peptide having four acidic amino acid residues took a maximum adsorbed amount, the reason for which is discussed.