Analysis of single-cell differences by use of an on-chip microculture system and optical trapping

A method is described for continuous observation of isolated single cells that enables genetically identical cells to be compared; it uses an on-chip microculture system and optical tweezers. Photolithography is used to construct microchambers with 5-microm-high walls made of thick photoresist (SU-8) on the surface of a glass slide. These microchambers are connected by a channel through which cells are transported, by means of optical tweezers, from a cultivation microchamber to an analysis microchamber, or from the analysis microchamber to a waste microchamber. The microchambers are covered with a semi-permeable membrane to separate them from nutrient medium circulating through a "cover chamber" above. Differential analysis of isolated direct descendants of single cells showed that this system could be used to compare genetically identical cells under contamination-free conditions. It should thus help in the clarification of heterogeneous phenomena, for example unequal cell division and cell differentiation.     

Feasibility study to investigate diffusion of Fe in Si using a Mössbauer spectroscopic microscope

A prototype Mössbauer Spectroscopic Microscope is applied for the feasibility study of ⁵⁷Fe impurity diffusion in Si wafers. A 2nm- ⁵⁷Fe deposited Si wafer is annealed at 430 °C for 1 hour, and subsequently the 1/3 area of the wafer is further grinded with an angle of 6 degrees to the original surface to get a higher depth resolution for the mapping. Subsequently, the mapping images for Fe\(_{\text {sub}}^{\mathrm {0}}\), Fe\(_{\text {int}}^{\mathrm {0}}\), and Fe\(_{\text {int}}^{\mathrm {+}}\) states are measured separately for the two different areas: one area (A) along the grinded surface, and the other (B) along the original wafer surface crossing through the ⁵⁷Fe-deposition boundary. By integrating the mapping intensity the diffusivity of each Fe component along the two different directions can be evaluated and compared with an average Fe diffusivity in Si, which is measured by EDS mapping data obtained for the same area.     

3D-Mössbauer spectroscopic microscope for mc-Si solar cell evaluation

A 3D-Mössbauer Spectroscopic Microscope is developed to evaluate Fe impurities in multi-crystalline Si solar cells, which combines the Mössbauer spectroscopic microscope with a scanning electron microscope (SEM), an electron beam induced current (EBIC), an electron backscatter diffraction (EBSD), and an electron energy analyzer (HV-CSA). In addition, a new moving-coil-actuator with a liner encoder of 100 nm-resolution is incorporated for the operations with both a constant velocity and a constant acceleration mode successfully with the same precision as that obtained by the conventional transducers. Furthermore, a new multi-capillary X-ray lens is designed to achieve a γ-ray spot size less than 100 μm in diameter. The new microscope provides us to investigate the space correlation between Fe impurities and the lattice defects such as grain boundaries in multi-crystalline Si solar cells.     

Facile preparation of chitin nanowhisker–gold nanocluster hybrids: effect of feeding ratio and surface amino group contents on gold absorption amount

Chitin nanowhiskers (ChNWs) hybridized with the densely adsorbed gold nanoclusters (AuNCs) were facilely prepared by a simple mixing of aqueous suspensions of ChNWs and AuNCs. Adsorption of AuNCs on the ChNW surface was confirmed by transmission electron microscopy and scanning electron microscopy with energy dispersive X‐ray spectroscopy. The amounts of adsorbed AuNCs measured by thermogravimetry and combustion using a muffle furnace were in good agreement. While the amount of adsorbed AuNCs increased with AuNCs/ChNWs feeding ratio, we found only a weak dependence of adsorbed AuNC amount on the surface amino group content of ChNWs controlled by pre‐deacetylation of the starting chitin. Copyright © 2016 John Wiley & Sons, Ltd.     

Molecular packing density of a self-assembled monolayer formed from N-(2-aminoethyl)-3-aminopropyltriethoxysilane by a vapor phase process

The molecular density of an aminosilane self-assembled monolayer formed from N-(2-aminoethyl)-3-aminopropyltriethoxysilane (AEAPS) by a vapor phase method has been estimated to be about 3 AEAPS molecules per nm(2) based on chemical labeling, optical absorption spectroscopy and X-ray photoelectron spectroscopy.