Optical authentication method using a three-dimensional phase object with various wavelength readouts

An optical system for authentication using a 3D (3D) random phase object with various wavelength readouts is proposed. The 3D phase object without surface modulation is secure when the scattering is strong enough because it prevents from the interferometric measurement. The identification is implemented by the correlation between a measured speckle pattern of the 3D phase object and stored speckle patterns. For accurate identification, two speckle patterns of the 3D object obtained by illuminating two wavelengths are used. Experimental demonstrations and numerical evaluations of wavelength selectivity are presented.     

Three-dimensional measurement and imaging based on multicameras randomly distributed on the circumference

We present a three-dimensional (3D) measurement and imaging based on a multicamera system. In the presented system, projected images of 3D objects are taken by cameras located at random positions on a circumference, and then the 3D objects can be reconstructed numerically. We introduce an angle correction function to improve the quality of the reconstructed object. The angle correction function can correct the angle error caused by the position errors in the projected images due to the finite pixel size of the image sensor. The numerical results show that the point source was reconstructed successfully by introducing the angle correction function. We also demonstrate experiments: the two objects are located on a rotary stage controlled by a computer, the projected images are taken by a single camera, and by using 33 projected images, the two objects are reconstructed successfully.     

Possible action of vasohibin-1 as an inhibitor in the regulation of vascularization of the bovine corpus luteum

The development of the corpus luteum (CL), which secretes large amounts of progesterone to establish pregnancy, is accompanied by active angiogenesis, vascularization, and lymphangiogenesis. Negative feedback regulation is a critical physiological mechanism. Vasohibin-1 (VASH1) was recently discovered as a novel endothelium-derived negative feedback regulator of vascularization. We therefore investigated the expression of VASH1 in the bovine CL. Expression of VASH1 mRNA and protein was predominantly localized to luteal endothelial cells (LECs). VASH1 expression in the CL was constant through the early to late luteal phases and decreased during CL regression relating with the action of luteolytic prostaglandin F(2)(α) in vivo. To investigate the role of VASH1, we determined whether VASH1 treatment affects angiogenesis and/or lymphangiogenesis using LECs and lymphatic endothelial cells (LyECs) in vitro. Vascular endothelial growth factor A (VEGFA) stimulated the expression of VASH1 in LECs but not in LyECs, and VASH1 completely blocked VEGFA-induced formation of capillary-like tube structures of LECs and LyECs in vitro. In summary, VASH1 is predominantly located on LECs in the bovine CL and inhibits the angiogenic and lymphangiogenic actions of VEGFA. Bovine CL therefore has a VEGFA-VASH1 system that may be involved in regulation of luteal function, especially in the development of the CL. The results indicate that VASH1 has the potential to act as a negative feedback regulator of angiogenesis and lymphangiogenesis in the CL in cows.     

In situ identification of microorganisms in biofilm communities

Diverse microorganisms form complex microbial communities and usually exist in biofilm communities in both natural environments and engineered systems such as a wastewater treatment process. However, the conventional approach to investigate microbial ecology has not contributed to the understanding and clarification of the structure and function of biofilm communities. Some effective methods have been developed to investigate phylogenetic affiliations, metabolic activities and genetic activities in biofilm communities at the single-cell level. These techniques have been contributing to a better understanding of the spatial organization of biofilm communities and activities in engineered systems. However, further effort is needed to set out the general rules governing community development in biofilm communities and to advance the process performance of engineered systems. This review describes advances and limitations in methodology, particularly focusing on fluorescence in situ hybridization (FISH) and related techniques and the application of these methods to nitrifying biofilms in wastewater treatment processes.     

Nano-cell fabrication on InSb utilizing point defects behavior induced by focused ion beam

In ion irradiated GaSb, InSb and Ge, the induced point defects form voids and these voids develop to the cells by further irradiation. The nano-fabrication technique utilizing this behavior is performed on (100) InSb by focused Ga⁺ ion beam (FIB). Fabrication of nano-cell lattices with cell an interval of 30-300 nm are tried varying the acceleration voltage and the ion dose at room temperature, and the plan views and the cross-sectional views of the nano-cell structures are observed by scanning electron microscopy (SEM). The possible ranges of the cell interval, the cell diameter and the cell height are obtained from the results.     

Construction of an expression system of insect lysozyme lacking thermal stability: the effect of selection of signal sequence on level of expression in the Pichia pastoris expression system

Expression systems of human and silkworm lysozymes were constructedusing the methylotrophic yeast Pichia pastoris as a host. Theleader sequence and its prepro peptide of     

Optical Energy Gap and Below Gap Optical Absorption of Fullerene Films Measured by the Constant Photocurrent Method and Photothermal Deflection Spectroscopy

The CPM spectra of fullerene films was measured to obtain the below gap absorption. The optical energy gap E_o was obtained by using the Tauc's plots. E_o did not change greatly with intercalated impurities. The absorption due to intercalated impurities was found below 1.6eV.     

Electric dichroism studies of the bonding of Co(III) chelate with synthetic polyelectrolytes

The interactions of bis-2-(2-pyridylazo)-1-naphthol Co(III), [Co(III) (αPAN)₂⁺], with five kinds of synthetic polyelectrolytes have been studied by spectrophotometric and transient electric dichroism measurements. The polyelectrolytes were: poly(styrene sulphonic acid) (PSS); poly(acrylic acid) (PAA); poly(l-glutamic acid) (PLG); $\text{poly}\text{(N}{}^{\mathrm{<mtext>e</mtext>}}\text{,N}{}^{\mathrm{<mtext>e</mtext>}}\text{-}\text{dicarboxylmethyl-}\text{l}\text{-lysine}$ (PDCML); and poly(l-lysine) (PLL). The equilibrium constant of the reaction:

with P = polyelectrolyte residue was determined spectrophotometrically: K₁ is > 10⁷ M^?1 (PSS); (1.4 ± 0.2) × 10⁴ M^?1 (PAA); (4.0 ± 0.4) × 10³ M^?1 (PLG); (1.4 ± 0.2) × 10⁶ M^?1 (PDCML); and < 10² M^?1 (PLL) at pH 6–8. From transient electric dichroism, the angle (ψ) between the αPAN plane and the polymer axis was determined to be 65° (PSS); 52° (PAA); 55° (PLG); and 52° (PDCML). The large K₁ and ψ values for PSS are ascribed to the hydrophobic interaction between the aromatic αPAN ring and the styrene sulphonate residues of PSS. Using stopped-flow electric dichroism measurements, rapid transfer of a bound Co(III) chelate from the PDCML to PSS chains was shown to occur.     

Improved electrochemical activity of LiMnPO4 by high-energy ball-milling

Olivine lithium manganese phosphate (LiMnPO₄) becomes research focus because of its high energy density and improved thermal stability. However, its application in lithium ion batteries suffers severely from poor electrochemical activity due to low conductivity and structural instability upon the charge and discharge process. By applying a high-energy ball-milling method we succeed in improving the capacity delivery and rate capability. LiMnPO₄ materials ball-milled without or with acetylene black are able to deliver a high capacity of 135 and 127 mAh g⁻¹, respectively, more than 50% greater than the pristine one. Particularly, the latter also shows an improved discharge plateau and stable cyclability. High-energy synchrotron radiation X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, laser particle analysis, and galvanostatic charge and discharge are employed to understand the effect of ball-milling on the LiMnPO₄ material.     

Stepwise polymerization of propylene and ethylene with Cr(acetylacetonate)3/MgCl2–ethylbenzoate/diethylaluminium chloride catalyst system

During propylene polymerization with the Cr(acetylacetonate)₃/MgCl₂–Et₂AlCl–ethylbenzoate catalyst system which shows high isospecificity for propylene polymerization, it was found that the chain transfer and termination reactions can be neglected. Based on this result, some stepwise polymerizations of propylene and ethylene were carried out with the same catalyst system varying polymerization conditions. The resulting copolymers were separated by temperature rising elution fractionation (TREF) and afforded two fractions which were eluted at different temperatures. From the ¹³C NMR, DSC and GPC analyses of each fraction, it was considered that the corresponding block copolymer existed in the fraction eluted at higher temperature. © 2003 Society of Chemical Industry