ABSTRACT We reanalyze data of the near-infrared background taken by IRTS using up-to-date observational results of zodiacal light (ZL), integrated star light, and diffuse Galactic light. We confirm ...the existence of residual isotropic emission, which is slightly lower but almost the same as previously reported. At wavelengths longer than 2 m, the result is fairly consistent with the recent observation with AKARI. We also perform the same analysis using a different ZL model by Wright and detect residual isotropic emission that is slightly lower than that based on the original Kelsall model. Both models show residual isotropic emission that is significantly brighter than the integrated light of galaxies.
During orofacial tissue development, the anterior and posterior regions of the Meckel’s cartilage undergo mineralization, while the middle region undergoes degeneration. Despite the interesting and ...particular phenomena, the mechanisms that regulate the different fates of Meckel’s cartilage, including the effects of biomechanical cues, are still unclear. Therefore, the purpose of this study was to systematically investigate the course of Meckel’s cartilage during embryonic development from a biomechanical perspective. Histomorphological and biomechanical (stiffness) changes in the Meckel’s cartilage were analyzed from embryonic day 12 to postnatal day 0. The results revealed remarkable changes in the morphology and size of chondrocytes, as well as the occurrence of chondrocyte burst in the vicinity of the mineralization site, an often-seen phenomenon preceding endochondral ossification. To understand the effect of biomechanical cues on Meckel’s cartilage fate, a mechanically tuned 3-dimensional hydrogel culture system was used. At the anterior region, a moderately soft environment (10-kPa hydrogel) promoted chondrocyte burst and ossification. On the contrary, at the middle region, a more rigid environment (40-kPa hydrogel) enhanced cartilage degradation by inducing a higher expression of MMP-1 and MMP-13. These results indicate that differences in the biomechanical properties of the surrounding environment are essential factors that distinctly guide the mineralization and degradation of Meckel’s cartilage and would be valuable tools for modulating in vitro cartilage and bone tissue engineering.
Quiescent prominences host a diverse range of flows, including Rayleigh-Taylor instability driven upflows and impulsive downflows, and so it is no surprise that turbulent motions also exist. As ...prominences are believed to have a mean horizontal guide field, investigating any turbulence they host could shed light on the nature of magnetohydrodynamic (MHD) turbulence in a wide range of astrophysical systems. In this paper we have investigated the nature of the turbulent prominence motions using structure function analysis on the velocity increments estimated from Hα Dopplergrams constructed with observational data from Hinode Solar Optical Telescope (SOT). The probability density function of the velocity increments shows that as we look at increasingly small spatial separations the distribution displays greater departure from a reference Gaussian distribution, hinting at intermittency in the velocity field. Analysis of the even order structure functions for both the horizontal and vertical separations showed the existence of two distinct regions displaying different exponents of the power law with the break in the power law at approximately 2000 km. We hypothesise this to be a result of internal turbulence excited in the prominence by the dynamic flows of the system found at this spatial scale. We found that the scaling exponents of the pth order structure functions for these two regions generally followed the p/ 2 (smaller scales) and p/ 4 (larger scales) laws that are the same as those predicted for weak MHD turbulence and Kraichnan-Iroshnikov turbulence respectively. However, the existence of the p/ 4 scaling at larger scales than the p/ 2 scaling is inconsistent with the increasing nonlinearity expected in MHD turbulence. We also found that as we went to higher order structure functions, the dependence of the scaling exponent on the order p is nonlinear implying that intermittency may be playing an important role in the turbulent cascade. Estimating the heating from the turbulent energy dissipation showed that this turbulence would be very inefficient at heating the prominence plasma, but that the mass diffusion through turbulence driven reconnection was of the order of 1010 cm2 s-1. This is of similar order to that of the expected value of the ambipolar diffusion and a few orders of magnitude greater than Ohmic diffusion for a quiescent prominence.
The possibility of p-wave pairing in superconductors has been proposed more than five decades ago, but has not yet been convincingly demonstrated. One difficulty is that some p-wave states are ...thermodynamically indistinguishable from s-wave, while others are very similar to d-wave states. Here we studied the self-field critical current of NdFeAs(O,F) thin films in order to extract absolute values of the London penetration depth, the superconducting energy gap, and the relative jump in specific heat at the superconducting transition temperature, and find that all the deduced physical parameters strongly indicate that NdFeAs(O,F) is a bulk p-wave superconductor. Further investigation revealed that single atomic layer FeSe also shows p-wave pairing. In an attempt to generalize these findings, we re-examined the whole inventory of superfluid density measurements in iron-based superconductors and show quite generally that single-band weak-coupling p-wave superconductivity is exhibited in iron-based superconductors.
Summary Objectives Human bone-marrow stromal cells are believed to be multipotent even in adults. This study assessed the effectiveness of autologous bone-marrow stromal cells, which were embedded ...within a collagen scaffold, to repair a full-thickness articular cartilage defect in the medial femoral condyle of an athlete. Patient and methods A 31-year-old male judo player suffering from pain in the right knee was reviewed. A 20 × 30-mm full-thickness cartilage defect (International Cartilage Repair Society classification (ICRS) grade IV) was revealed in the weight-bearing area of the medial femoral condyle. With the informed consent of the patient, the defect was treated with autologous bone-marrow stromal cells. Bone marrow was aspirated from the iliac crest of the patient 4 weeks before surgery. After removing the erythrocytes, the remaining cells were expanded in culture. Adherent cells were collected and embedded within a collagen gel, which was transferred to the articular cartilage defect in the medial femoral condyle. The implant was covered with an autologous periosteal flap. Results Seven months after surgery, arthroscopy revealed the defect to be covered with smooth tissues. Histologically, the defect was filled with a hyaline-like type of cartilage tissue which stained positively with Safranin-O. One year after surgery, the clinical symptoms had improved significantly. The patient had reattained his previous activity level and experienced neither pain nor other complications. Conclusions Our findings indicate that the transplantation of autologous bone-marrow stromal cells can promote the repair of large focal articular cartilage defects in young, active patients.
Previous research showed that the functional monomer 10-methacryloxydecyl dihydrogen phosphate (MDP) ionically bonds to hydroxyapatite (HAp) and forms a nano- layered structure at the interface with ...HAp-based substrates. Such hydrophobic nano-layering is considered to contribute to the long-term durability of the bond to tooth tissue. However, dental adhesives are complex mixtures usually containing different monomers. This study investigated the effect of the monomer 2-hydroxyethylmethacrylate (HEMA) on the chemical interaction of MDP with HAp by x-ray diffraction (XRD), nuclear magnetic resonance (NMR), and quartz crystal microbalance (QCM). We examined the chemical interaction of 5 experimental MDP solutions with increasing concentrations of HEMA. XRD revealed that addition of HEMA inhibits nano-layering at the interface, while NMR confirmed that MDP remained adsorbed onto the HAp surface. QCM confirmed this adsorption of MDP to HAp, as well as revealed that the demineralization rate of HAp by MDP was reduced by HEMA. It was concluded that even though the adsorption of MDP to HAp was not hindered, addition of HEMA inhibited interfacial nano-layering. Potential consequences with regard to bond durability necessitate further research.
We investigated the roles of osteocytes in osteoclastic bone resorption during orthodontic tooth movement using the transgenic mice in which osteocytes can be specifically ablated. Because these ...transgenic mice express the receptor for diphtheria toxin on the cell surfaces of osteocytes, the injection of diphtheria toxin can ablate their osteocytes in vivo. Injection of diphtheria toxin into the transgenic mice significantly increased the number of ablated osteocytes in alveolar bone compared with that in wild-type mice with or without diphtheria toxin injection. Increased numbers of ablated osteocytes were observed from day 4 to day 12 after the injection in alveolar bones as well as in cortical bone of the tibiae. We applied the orthodontic force 4 days after the injection of diphtheria toxin, and the distance of tooth movement on day 12 was significantly smaller in transgenic mice than that in control mice. The numbers of osteoclasts and the quantity of eroded bone surface at the compression site were significantly reduced in the transgenic mice injected with diphtheria toxin than in control mice. These results provide in vivo demonstration of osteocyte involvement in osteoclastic bone resorption during orthodontic tooth movement.
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