Spatially Resolving Substructures within the Massive Envelope around an Intermediate-mass Protostar: MMS 6/OMC-3

With the Submillimeter Array, the brightest (sub)millimeter continuum source in the OMC-2/3 region, MMS 6, has been observed in the 850 um continuum emission with approximately 10 times better angular resolution than previous studies (~0.3"; ~120 AU at Orion). The deconvolved size, the mass, and the column density of MMS 6-main are estimated to be 0.32"x0.29" (132 AUx120 AU), 0.29 Mo, and 2.1x10^{25} cm^{-2}, respectively. The estimated extremely high mean number density, 1.5x10^{10} cm^{-3}, suggests that MMS 6-main is likely optically thick at 850 um. We compare our observational data with three theoretical core models: prestellar core, protostellar core + disk-like structure, and first adiabatic core. These comparisons clearly show that the observational data cannot be modeled as a simple prestellar core with a gas temperature of 20 K. A self-luminous source is necessary to explain the observed flux density in the (sub)millimeter wavelengths. Our recent detection of a very compact and energetic outflow in the CO (3-2) and HCN (4-3) lines, supports the presence of a protostar. We suggest that MMS 6 is one of the first cases of an intermediate mass protostellar core at an extremely young stage. In addition to the MMS 6-main peak, we have also spatially resolved a number of spiky structures and sub-clumps, distributed over the central 1000 AU. The masses of these sub-clumps are estimated to be 0.066-0.073 Mo, which are on the order of brown dwarf masses. Higher angular resolution and higher sensitivity observations with ALMA and EVLA will reveal the origin and nature of these structures such as whether they are originated from fragmentations, spiral arms, or inhomogeneity within the disk-like structures/envelope.Comment: Accepted to Ap

Comparative examination of subcutaneous tissue reaction to high molecular materials in medical use

Polypropylene (PP), Polyethylene (PE) and polytetra-fluoroethylene (FE) are high molecular materials in medical use. They are also used as the negative control materials for ISO 10993-6 international standard biological evaluation of medical devices. We examined tissue reactions to these materials embedded subcutaneously in the dorsal area of male ddY mice. One week and 12 weeks after embedding, the tissue surrounding the embeddingg site was removed and then histopathological examination was performed. Our results demonstrate that the basic histopathological reaction is the formation of fibrous capsule consisting of granulation tissue around the embedded materials. Based on our results, we believe that the high molecular materials such as, PP, PE and FE, can be considered for medical use as a biomaterials within the body

Histopathological examination of newly-developed adhesive silicone denture relining material

We aimed to evaluate the subcutaneous tissue reaction to a newly developed adhesive silicone denture relining material, SG, (Neo Dental Chemical Products Co., Ltd. Tokyo, Japan). We embedded the experimental material SG and another existing control material, Roeko Seal (RS), in the dorsal area of 22 male ddY mice. One week and 12 weeks after the embedding, the tissues surrounding the embedded materials were removed and a histopathological examination was performed. The results demonstrate that the basic histopathological aspects are the formation of granulation tissue and the change of the tissue to fibrous capsule over time. The results suggests that the newly-developed SG is safe as compared with the control RS, whose composition is similar

Structure, Stresses and Local Dynamics in Glasses

The interrelations between short range structural and elastic aspects in glasses and glass forming liquids pose important and yet unresolved questions. In this paper these relations are analyzed for mono-atomic glasses and stressed liquids with a short range repulsive-attractive pair potentials. Strong variations of the local pressure are found even in a zero temperature glass, whereas the largest values of pressure are the same in both glasses and liquids. The coordination number z(J) and the effective first peak radius depend on the local pressures J's. A linear relation was found between components of site stress tensor and the local elastic constants. A linear relation was also found between the trace of the squares of the local frequencies and the local pressures. Those relations hold for glasses at zero temperature and for liquids. We explain this by a relation between the structure and the potential terms. A structural similarity between liquids and solids is manifested by similar dependencies of the coordination number on the pressures.Comment: 7 pages, 11 figure

Histopathological Safety Evaluation of Newly-Developed MgO Sealer

We aimed to evaluate the subcutaneous tissue reaction to a newly-developed MgO Sealer for root canals. We injected the experimental material and three existing control materials into the dorsal area of 43 male ddY mice. One week and 12 weeks after embedding, the tissue surrounding the embedding sites was removed and histopathological examination was performed. The results demonstrate that the basic histopathological reaction is the formation of fibrous capsules consisting of granulation tissue around the experimental and control embedded materials. Based on our results, we believe that the newly-developed MgO Sealer is as safe as the existing control materials and can be considered for dental use as a root canal sealer