Three-dimensional microscope tracking system using the astigmatic lens method and a profile sensor

We developed a three-dimensional microscope tracking system using the astigmatic lens method and a profile sensor, which provides three-dimensional position detection over a wide range at the rate of 3.2 kHz. First, we confirmed the range of target detection of the developed system, where the range of target detection was shown to be ±?90 µm in the horizontal plane and ±?9 µm in the vertical plane for a 10× objective lens. Next, we attempted to track a motion-controlled target. The developed system kept the target at the center of the field of view and in focus up to a target speed of 50 µm/s for a 20× objective lens. Finally, we tracked a freely moving target. We successfully demonstrated the tracking of a 10-µm-diameter polystyrene bead suspended in water for 40 min. The target was kept in the range of approximately 4.9 µm around the center of the field of view. In addition, the vertical direction was maintained in the range of ±?0.84 µm, which was sufficiently within the depth of focus.     

Facile Synthesis of Linear and Cyclic Poly(diphenylacetylene)s by Molybdenum and Tungsten Catalysis

Improved methods for the synthesis of linear and cyclic poly(diphenylacetylene)s by polymerization of the corresponding diphenylacetylenes using MoCl₅- and WCl₄-based catalytic systems have been developed. MoCl₅ induces migratory insertion polymerization of diphenylacetylenes in the presence of arylation reagents such as Ph₄Sn and ArSnⁿBu₃ to produce cis-stereoregular linear poly(diphenylacetyelene)s with high molecular weights (number-average molar mass (M_n)=30,000–3,200,000) in good yields (up to 98 %). On the other hand, WCl₄ induces ring expansion polymerization of diphenylacetylenes in the presence of Ph₄Sn or reducing reagents to produce cis-stereoregular cyclic poly(diphenylacetylene)s with high molecular weights (M_n=20,000–250,000) in moderate to good yields (up to 90 %). Both catalytic systems are applicable to the polymerization of various diphenylacetylenes having polar functional groups such as esters that are not efficiently polymerized by conventional methods using WCl₆-Ph₄Sn and TaCl₅-ⁿBu₄Sn systems.     

Compressed sensing by two-directional line sensing

Optical Review - We propose an imaging method using commercially available profile sensor. Specifically, we use a multipixel CMOS area sensor capable of acquiring projection profiles and perform...     

Macromolecular helicity inversion of poly(phenylacetylene) derivatives induced by various external stimuli

Unique macromolecular helicity inversion of stereoregular, optically active poly(phenylacetylene) derivatives induced by external achiral and chiral stimuli is briefly reviewed. Stereoregular, cis-transoidal poly(phenylacetylene)s bearing an optically active substituent, such as (1R,2S)-norephedrine (poly- 1 ) and β-cyclodextrin residues (poly- 2 ), show an induced circular dichroism (ICD) in the UV-visible region of the polymer backbone in solution due to a predominantly one-handed helical conformation of the polymers. However, poly- 1 undergoes a helix-helix transition upon complexation with chiral acids having an R configuration, and the complexes exhibit a dramatic change in the ICD of poly- 1 . Poly- 2 also shows the inversion of macromolecular helicity responding to molecular and chiral recognition events that occurred at the remote cyclodextrin residues from the polymer backbone; the helicity inversion is accompanied by a visible color change. A similar helix-helix transition of poly((R)- or (S)-(4-((1-(1-naphthyl)ethyl)carbamoyl)phenyl)acetylene) is also briefly described.