Topical application of Porphyromonas gingivalis into the gingival pocket in mice leads to chronic­active infection, periodontitis and systemic inflammation.

Porphyromonas gingivalis (Pg), one of the 'red­complex' perio­pathogens known to play a critical role in the development of periodontitis, has been used in various animal models to mimic human bacteria­induced periodontitis. In order to achieve a more realistic animal model of human Pg infection, the present study investigated whether repeated small­volume topical applications of Pg directly into the gingival pocket can induce local infection, including periodontitis and systemic vascular inflammation in wild­type mice. Freshly cultured Pg was topically applied directly into the gingival pocket of the second molars for 5 weeks (3 times/week). After the final application, the mice were left in cages for 4 or 8 weeks and sacrificed. The status of Pg colony formation in the pocket, gingival inflammation, alveolar bone loss, the expression levels of pro­inflammatory cytokines in the serum and aorta, the presence of anti­Pg lipopolysaccharide (LPS) and gingipain (Kpg and RgpB) antibodies in the serum, as well as the accumulation of Pg LPS and gingipain aggregates in the gingiva and arterial wall were evaluated. The topical application of Pg into the gingival pocket induced the following local and systemic pathohistological changes in mice when examined at 4 or 8 weeks after the final topical Pg application: Pg colonization in the majority of gingival pockets; increased gingival pocket depths; gingival inflammation indicated by the increased expression of TNF­α, IL­6 and IL­1ß; significant loss of alveolar bone at the sites of topical Pg application; and increased levels of pro­inflammatory cytokines, such as TNF­α, IL­1ß, IL­17, IL­13, KC and IFN­Î³ in the serum in comparison to those from mice receiving PBS. In addition, the Pg application/colonization model induced anti­Pg LPS and gingipain antibodies in serum, as well as the accumulation of Pg LPS and gingipain aggregates in the gingivae and arterial walls. To the best of our knowledge, this mouse model represents the first example of creating a more sustained local infection in the gingival tissues of wild­type mice and may prove to be useful for the investigation of the more natural and complete pathogenesis of the bacteria in the development of local oral and systemic diseases, such as atherosclerosis. It may also be useful for the determination of a treatment/prevention/efficacy model associated with Pg­induced colonization periodontitis in mice.

Biological properties of butanol extracts from green pine cone of Pinus densiflora.

This study examined the biological functions of the butanol extracts of green pine cones (GPCs) that had not ripened completely. The butanol extracts of GPC showed 78.22% DPPH-scavenging activity, 53.55% TEAC and 71.50% hyaluronidase (HAase) inhibition activity. They also exhibited inhibition activity against food poisoning microorganisms. The contents of total phenolic compounds and total flavonoids were 296.75 and 26.07 mg/g, respectively. Biologically active compounds were analyzed and separated using HPLC related to the DPPH-scavenging and HAase inhibition activities. Gallotannin was the primary biologically active compound with DPPH-scavenging and HAase inhibition activities in the GPC butanol extracts.

Optimal Fermentation Conditions of Hyaluronidase Inhibition Activity on Asparagus cochinchinensis Merrill by Weissella cibaria.

This study was conducted to evaluate the hyaluronidase (HAase) inhibition activity of Asparagus cochinchinesis (AC) extracts following fermentation by Weissella cibaria through response surface methodology. To optimize the HAase inhibition activity, a central composite design was introduced based on four variables: the concentration of AC extract (X1: 1-5%), amount of starter culture (X2: 1-5%), pH (X3: 4-8), and fermentation time (X4: 0-10 days). The experimental data were fitted to quadratic regression equations, the accuracy of the equations was analyzed by ANOVA, and the regression coefficients for the surface quadratic model of HAase inhibition activity in the fermented AC extract were estimated by the F test and the corresponding p values. The HAase inhibition activity indicated that fermentation time was most significant among the parameters within the conditions tested. To validate the model, two different conditions among those generated by the Design Expert program were selected. Under both conditions, predicted and experimental data agreed well. Moreover, the content of protodioscin (a well-known compound related to anti-inflammation activity) was elevated after fermentation of the AC extract at the optimized fermentation condition.

Temperature dependence of convective heat transfer with Al2O3 nanofluids in the turbulent flow region.

An experimental investigation on the characteristics of the convective heat transfer in the fully developing region of a circular straight tube with a constant heat flux was carried out with Al2O3 nanofluids. Stable nanofluids, which were water-based suspensions of Al2O3 nanoparticles, were prepared by two-step method. The effects of the thermal conductivity, viscosity, and heat capacity of the nanofluids on convective heat transfer were investigated. The result showed that the coefficient enhancement of the convective heat transfer in the Al2O3 nanofluids was increased with increasing fluid temperature compared to that of water at a volume fraction of 3.0% in the turbulent flow region. Thermal conductivity was increased from 8% to 20%, and the increment of convective heat transfer coefficient was enhanced from 14% to 30% with fluid temperature from 22 degrees C to 75 degrees C, respectively. We observed that the increment of convective heat transfer coefficient in nanofluids was much higher than that of the thermal conductivity at a given temperature condition. The enhancement of Brownian motion due to the decreasing kinematic viscosity led to a higher convective heat transfer coefficient at a higher temperature condition.

Round-robin test on thermal conductivity measurement of ZnO nanofluids and comparison of experimental results with theoretical bounds.

Ethylene glycol (EG)-based zinc oxide (ZnO) nanofluids containing no surfactant have been manufactured by one-step pulsed wire evaporation (PWE) method. Round-robin tests on thermal conductivity measurements of three samples of EG-based ZnO nanofluids have been conducted by five participating labs, four using accurate measurement apparatuses developed in house and one using a commercial device. The results have been compared with several theoretical bounds on the effective thermal conductivity of heterogeneous systems. This study convincingly demonstrates that the large enhancements in the thermal conductivities of EG-based ZnO nanofluids tested are beyond the lower and upper bounds calculated using the models of the Maxwell and Nan et al. with and without the interfacial thermal resistance.

Comparative analysis of trap-based program/erase behaviors with different tunnel barriers.

In this study, we comparatively analyze the trap-based memory characteristics of Oxide-Nitride-Oxide (ONO) devices with different tunnel dielectrics. We fabricated two kinds of ONO devices-one is the conventional single tunnel oxide structure and the other is the bandgap engineered structure in which the modulated tunnel dielectric replaces the single tunnel oxide. The charge storage layer is 9 nm and the blocking oxide is 7 nm in both two kinds of ONO devices. Based on experimental results, we find that the memory speed is promoted to 2-4 times and 10-year data retention greatly improves in the bandgap engineered device comparing to those in the conventional device. As a result, the bandgap engineered tunnel barrier device embodies both fast P/E operation speeds and excellent long-term data retention characteristics, hence, the bandgap engineered tunnel barrier is expected to conduct performance optimization for the future scaled SONOS flash memory.

Polyelectrolyte-assisted synthesis of polystyrene microspheres by dispersion polymerization and the subsequent formation of silica shell.

Polystyrene (PS) microspheres were synthesized via dispersion polymerization in alcoholic media. A cationic polyelectrolyte, polyethyleneimine (PEI) was successfully used as a steric stabilizer. The concentration of initiator, monomer, and the solubility parameter of medium showed typical phenomena observed in dispersion polymerization. However, the sensitivity to the change in the particles size was almost twofold greater than conventional stabilizers. Spherical PS particles were synthesized with the PEI concentrations ranging from 5 to 20 wt.% to styrene, but conversion over 95% was achieved over 10 wt.% PEI. As-prepared PEI-stabilized PS microspheres were used as the template for the subsequent formation of a silica shell. As a result, a robust silica layer was fabricated on PS microspheres due to the increased interaction between PEI and tetraethyl orthosilicate (TEOS).

Enantioselective synthesis of (R)-(+)- and (S)-(-)-higenamine and their analogues with effects on platelet aggregation and experimental animal model of disseminated intravascular coagulation.

Optically active tetrahydroisoquinoline alkaloids, (R)-(+)-higenamine (1R) and (S)-(-)-higenamine (1 S), and their optically active 1-naphthylmethyl analogues (2 and 3), were synthesized by enantioselective hydrogenation of the corresponding dihydroisoquinoline intermediates 7 as a key step. The evaluation of the platelet anti-aggregation effect demonstrated clearly that the (S)-(-)-enantiomers, 1S, 2S, and 3S, had higher inhibitory potency than the corresponding (R)-(+)-antipodes, 1R, 2R, and 3R, respectively, to platelet aggregation induced by epinephrine. 1S enantiomer was superior to the corresponding 1R enantiomer in attenuating all of the disseminated intravascular coagulation (DIC) and multiple organ failure (MOF) parameters tested, while the S enantiomers 2S and 3S ameliorated some of the DIC and MOF parameters more effectively than the corresponding antipodes 2R and 3R.