A Novel Photonic Material for Designing Arbitrarily Shaped Waveguides in Two Dimensions

We investigate numerically optical properties of novel two-dimensional photonic materials where parallel dielectric rods are randomly placed with the restriction that the distance between rods is larger than a certain value. A large complete photonic gap (PG) is found when rods have sufficient density and dielectric contrast. Our result shows that neither long-range nor short-range order is an essential prerequisite to the formation of PGs. A universal principle is proposed for designing arbitrarily shaped waveguides, where waveguides are fenced with side walls of periodic rods and surrounded by the novel photonic materials. We observe highly efficient transmission of light for various waveguides. Due to structural uniformity, the novel photonic materials are best suited for filling up the outer region of waveguides of arbitrary shape and dimension comparable with the wavelength.Comment: 4 figure

Effects of visual stimulation using wooden-wall images with different amounts of knots on psychological and physiological responses

Wood is an important material used in decorating human living environment. Knots are prominent features found on wood surface. Moreover, they are commonly considered as undesirable surface defects, which reduce not only the mechanical properties but also the aesthetic qualities of lumber. The effects of visual stimulation using knotty wood on psychological responses among humans have been relatively well investigated. However, only few studies have assessed physiological responses. Hence, the present study aimed to assess whether knotty wood surface can reduce not only psychological but also physiological benefits for humans. Two full-sized knotty wooden-wall images and a clear wooden-wall image were used as visual stimuli using computer graphics techniques. Twenty-eight adult Japanese female university students viewed each image for 90 s in random order. During exposure to the visual stimuli, the oxyhemoglobin concentrations in the left and right prefrontal cortex and heart rate variability were consecutively measured and utilized as indicators of central and autonomic nervous system activities, respectively. In addition, the psychological effects of knotty images were examined using the modified semantic differential method and the Profile of Mood State 2nd Edition. There was no significant difference in the effects of the three images on physiological responses. All visual stimuli more or less promoted psychological comfort and relaxation. However, compared with the clear wooden-wall image, the wooden-wall image with several knots was associated with reduced psychological benefits, and the psychological responses in viewing the wooden-wall image with few knots did not remarkably differ

Activation of the IKK2/NF-κB pathway in VSMCs inhibits calcified vascular stiffness in CKD

IKK2/NF-κB pathway–mediated inflammation in vascular smooth muscle cells (VSMCs) has been proposed to be an etiologic factor in medial calcification and stiffness. However, the role of the IKK2/NF-κB pathway in medial calcification remains to be elucidated. In this study, we found that chronic kidney disease (CKD) induces inflammatory pathways through the local activation of the IKK2/NF-κB pathway in VMSCs associated with calcified vascular stiffness. Despite reducing the expression of inflammatory mediators, complete inhibition of the IKK2/NF-κB pathway in vitro and in vivo unexpectedly exacerbated vascular mineralization and stiffness. In contrast, activation of NF-κB by SMC-specific IκBα deficiency attenuated calcified vascular stiffness in CKD. Inhibition of the IKK2/NF-κB pathway induced cell death of VSMCs by reducing anti–cell death gene expression, whereas activation of NF-κB reduced CKD-dependent vascular cell death. In addition, increased calcification of extracellular vesicles through the inhibition of the IKK2/NF-κB pathway induced mineralization of VSMCs, which was significantly reduced by blocking cell death in vitro and in vivo. This study reveals that activation of the IKK2/NF-κB pathway in VSMCs plays a protective role in CKD-dependent calcified vascular stiffness by reducing the release of apoptotic calcifying extracellular vesicles

Isotropic photonic band gap and anisotropic structures in transmission spectra of two-dimensional 5-fold and 8-fold symmetric quasiperiodic photonic crystals

We measured and calculated transmission spectra of two-dimensional quasiperiodic photonic crystals (PCs) based on a 5-fold (Penrose) or 8-fold (octagonal) symmetric quasiperiodic pattern. The photonic crystal consisted of dielectric cylindrical rods in air placed normal to the basal plane on vertices of tiles composing the quasiperiodic pattern. An isotropic photonic band gap (PBG) appeared in the TM mode, where electric fields were parallel to the rods, even when the real part of a dielectric constant of the rod was as small as 2.4. An isotropic PBG-like dip was seen in tiny Penrose and octagonal PCs with only 6 and 9 rods, respectively. These results indicate that local multiple light scattering within the tiny PC plays an important role in the PBG formation. Besides the isotropic PBG, we found dips depending on the incident angle of the light. This is the first report of anisotropic structures clearly observed in transmission spectra of quasiperiodic PCs. Based on rod-number and rod-arrangement dependence, it is thought that the shapes and positions of the anisotropic dips are determined by global multiple light scattering covering the whole system. In contrast to the isotropic PBG due to local light scattering, we could not find any PBGs due to global light scattering even though we studied transmission spectra of a huge Penrose PC with 466 rods.Comment: One tex file for manuscript and 12 PNG files for figures consisting of Fig.1a-d, 2,3, ...

Physiological effects of visual stimulation with full-scale wall images composed of vertically and horizontally arranged wooden elements

Wood is a raw material that is used not only in the production of structural members for various buildings, but also in the interior finishes that are directly seen and touched by the occupants. Wood has also been recognized as a human-friendly material, but few studies have experimentally confirmed the physiological benefits it brings to humans. Therefore, the aim of the present study was to investigate the physiological effects of visual stimulation with wood. Two types of full-scale square, wooden-wall images composed of vertically or horizontally arranged lumber, were prepared using computer graphics and projected onto a large display to create the visual stimuli, and a gray image was also prepared as a control. Twenty-eight female Japanese university students participated in the study. The participants initially spent 60 s viewing the gray background (rest period) and then observed each of the wooden-wall images and the gray image separately in a random order for 90 s each. During the visual stimulation, the oxyhemoglobin (oxy-Hb) concentration as an indicator of prefrontal brain activity and heart rate variability as an indicator of autonomic nervous activity were continuously measured in each participant. Subjective evaluation of each visual stimulus was then performed using a modified semantic differential method and the Profile of Mood States 2nd Edition test. It was found that visual stimulation with either of the wooden interior wall images induced a significant decrease in oxy-Hb concentration in the left and right prefrontal cortex compared with the gray image. Furthermore, the subjective evaluation showed that the wooden-wall images provided a significantly more “comfortable, ” “relaxed, ” and “natural” impression than the gray image and decreased the negative mood states, with the vertically arranged wooden-wall image having a more positive effect than the horizontally arranged image

Influence of Light Intensity on Surface Free Energy and Dentin Bond Strength of Core Build-up Resins

Objective: We examined the influence of light intensity on surface free energy characteristics and dentin bond strength of dual-cure direct core build-up resin systems. Methods: Two commercially available dual-cure direct core build-up resin systems, Clearfil DC Core Automix with Clearfil Bond SE One and UniFil Core EM with Self-Etching Bond, were studied. Bovine mandibular incisors were mounted in acrylic resin and the facial dentin surfaces were wet ground on 600-grit silicon carbide paper. Adhesives were applied to dentin surfaces and cured with light intensities of 0 (no irradiation), 200, 400, and 600 mW/cm2. The surface free energy of the adhesives (five samples per group) was determined by measuring the contact angles of three test liquids placed on the cured adhesives. To determine the strength of the dentin bond, the core build-up resin pastes were condensed into the mold on the adhesive-treated dentin surfaces according to the methods described for the surface free energy measurement. The resin pastes were cured with the same light intensities as those used for the adhesives. Ten specimens per group were stored in water maintained at 37°C for 24 hours, after which they were shear tested at a crosshead speed of 1.0 mm/minute in a universal testing machine. Two-way analysis of variance (ANOVA) and a Tukey-Kramer test were performed, with the significance level set at 0.05. Results: The surface free energies of the adhesive-treated dentin surfaces decreased with an increase in the light intensity of the curing unit. Two-way ANOVA revealed that the type of core build-up system and the light intensity significantly influence the bond strength, although there was no significant interaction between the two factors. The highest bond strengths were achieved when the resin pastes were cured with the strongest light intensity for all the core build-up systems. When polymerized with a light intensity of 200 mW/cm2 or less, significantly lower bond strengths were observed. Conclusions: The data suggest that the dentin bond strength of core build-up systems are still affected by the light intensity of the curing unit, which is based on the surface free energy of the adhesives. On the basis of the results and limitations of the test conditions used in this study, it appears that a light intensity of >400 mW/cm2 may be required for achieving the optimal dentin bond strength

Tie2-Cre Transgenic Mice: A New Model for Endothelial Cell-Lineage Analysis in Vivo

AbstractEndocardial cells are thought to contribute at least in part to the formation of the endocardial cushion mesenchyme. Here, we created Tie2-Cre transgenic mice, in which expression of Cre recombinase is driven by an endothelial-specific promoter/enhancer. To analyze the lineage of Cre expressing cells, we used CAG-CAT-Z transgenic mice, in which expression of lacZ is activated only after Cre-mediated recombination. We detected pan-endothelial expression of the Cre transgene in Tie2-Cre;CAG-CAT-Z double-transgenic mice. This expression pattern is almost identical to Tie2-lacZ transgenic mice. However, interestingly, we observed strong and uniform lacZ expression in mesenchymal cells of the atrioventricular canal of Tie2-Cre;CAG-CAT-Z double-transgenic mice. We also detected lacZ expression in the mesenchymal cells in part of the proximal cardiac outflow tract, but not in the mesenchymal cells of the distal outflow tract and branchial arch arteries. LacZ staining in Tie2-Cre;CAG-CAT-Z embryos is consistent with endocardial–mesenchymal transformation in the atrioventricular canal and outflow tract regions. Our observations are consistent with previously reported results from Cx43-lacZ, Wnt1-Cre;R26R, and Pax3-Cre;R26R transgenic mice, in which lacZ expression in the cardiac outflow tract identified contributions in part from the cardiac neural crest. Tie2-Cre transgenic mice are a new genetic tool for the analyses of endothelial cell-lineage and endothelial cell–specific gene targeting

Utilization of Chinese fast-growing trees and the effect of alternating lamination using mixed-species eucalyptus and poplar veneers

Over the past few decades, the sustainable forest area in China has increased remarkably, with 2400 million cubic meters of eucalyptus produced in 2018 in Guangxi which is the largest plantation area in China. In this study, the effect of alternating lamination using soft poplar veneers and hard eucalyptus veneers, on the mechanical properties of laminated veneer lumber (LVL), was examined. Eucalyptus and poplar veneers were imported from China to Japan to manufacture the LVL. For both eucalyptus and poplar veneers, the pith side (innerwood) sheets were lighter in density than the bark side (outerwood) sheets. The specific Young’s modulus of alternating LVL with hard eucalyptus veneers and soft poplar veneers was smaller than that of the mono-species LVL of eucalyptus and poplar. Strain distributions were obtained with the compression test by using the digital image correlation method. Normal strains showed that the hard eucalyptus layer behaved as a thin plate, whereas the soft poplar layer mitigated the movement of the hard eucalyptus layer. Alternating lamination decreased the variation in the elastic modulus of LVL made from fast-growing species. Therefore, the soft layers mitigated the movement of the hard layers, which had large variations in mechanical properties