Simultaneous B-M-mode scanning method for real-time full-range Fourier domain optical coherence tomography

High-speed complex full-range Fourier domain optical coherence tomography (FD-OCT) is demonstrated. In this FD-OCT, the phase modulation of a reference beam (M scan) and transversal scanning (B scan) are simultaneously performed. The Fourier transform method is applied along the direction of the B scan to reconstruct complex spectra, and the complex spectra comprise a full-range OCT image. Because of this simultaneous B-M-mode scan, the FD-OCT requires only a single A scan for each single transversal position to obtain a full-range FD-OCT image. A simple but slow version of the FD-OCT visualizes the cross section of a plastic plate. A modified fast version of this FD-OCT investigates a sweat duct in a finger pad in vivo and visualizes it with an acquisition time of 27 ms.     

Profile structure of magnetic flux lines in type-II superconductor from a rectangular electron hologram

Profile magnetic configuration of a quantized flux line and flux-line lattice penetrating a type-II superconductor thin foil, niobium, was observed by electron holography and Lorentz microscopy using a 300 kV field-emission electron microscope. Each single flux line was distributed periodically as lattice structure in the mixed state just below its critical temperature of 8.5 K, while at low temperature of 5 K the flux lines were weakly bound as bundles. In order to observe the flux-line distribution over a wide area, discrete Fourier transform reconstruction in the holography was extended for a rectangular area without loss of information and data precision.     

Synthesis of poly(tetrahydrofuran-b-ε-caprolactone) macromonomer via the Sml2-induced transformation

Summary A novel well-defined macromonomer consisting of different types of monomers in polymerization mechanisms was synthesized for the first time through the SmI₂-induced transformation. The macromonomer, -methacryloylpoly-(tetrahydrofuran-b--caprolactone), was prepared by the reaction of methacryloyl chloride with living poly(tetrahydrofuran-b--caprolactone) [poly(THF-b-CL)] which was obtained by the two-electron reduction of the cationic growing center of poly(THF) by samarium iodide (SmI₂) followed by the polymerization of CL. ¹H NMR analysis indicated the quantitative introduction of the methacryloyl group onto the polymer end. The molecular weight distribution of the macromonomer was relatively narrow, and the unit ratio of THF to CL could be controlled by both polymerization time of THF and the amount of CL, resulting from the living nature of both CL- and THF-polymerizations. Radical copolymerization of the produced macromonomers with methyl methacrylate in the presence of AIBN resulted in a polymethacrylate backbone grafted with poly(THF-b-CL) block copolymers.     

A case-control study of the association between urinary cadmium concentration and endometriosis in infertile Japanese women

Cadmium may act like an estrogen and be a potential risk factor for estrogen-related diseases such as breast cancer and endometriosis. Here, we tested the hypothesis that higher cadmium exposure is associated with endometriosis among infertile Japanese women in a hospital-based case-control study. We recruited consecutive female patients aged 20-45 years who had complained of infertility and presented to a university hospital in Tokyo. The subjects were interviewed and provided a urine sample prior to a laparoscopic diagnosis of endometriosis between January 2000 and December 2001. The severity of endometriosis was then dichotomized into controls (stage 0 and I) and cases (stage II-IV). We finally measured urinary total cadmium concentration in 54 cases and 74 controls as a biomarker of long-term cumulative exposure. Odds ratios were adjusted for average menstrual cycle length, body-mass index and smoking status using unconditional logistic regression. Results showed no association between endometriosis and urinary cadmium concentration. Medians (interquartile ranges) of urinary cadmium concentration in cases and controls were 0.53 (0.40-0.73) and 0.54 (0.34-0.76) microg/g creatinine, respectively (P for difference=0.88). Adjusted odds ratio (95% confidence interval) for the highest versus lowest tertile of urinary creatinine-adjusted cadmium concentration was 0.86 (0.30 to 2.49, P for trend=0.79). Our results do not support the hypothesis that higher urinary cadmium concentration is associated with the risk of endometriosis.     

Feasibility of using U to reconstruct close-in fallout deposition from the Hiroshima atomic bomb

The first results on the feasibility of using ²³⁶U to reconstruct the level and spatial distribution of close-in fallout deposition from the Hiroshima A-bomb are reported, coupled with the use of global fallout ¹³⁷Cs and ^239 + 240Pu. The results for global fallout ²³⁶U in soil samples (0-30 cm) from Ishikawa prefecture showed that the deposition density of ²³⁶U from the global fallout can be accurately evaluated using AMS. All deposited ²³⁶U, ¹³⁷Cs and ^239 + 240Pu appeared to have been recovered using 30-cm cores. It was also noted from the depth profiles for ²³⁶U/^239 + 240Pu and ²³⁶U/¹³⁷Cs ratios that the downward behavior of ²³⁶U in the soil was apparently similar to that of ^239 + 240Pu, while the ¹³⁷Cs was liable to be retained in upper layers compared with ²³⁶U and ^239 + 240Pu. The accumulated levels were 1.78 × 10¹³ atoms m^− 2 for ²³⁶U, 4340 Bq m^− 2 for ¹³⁷Cs and 141 Bq m^− 2 for ^239 + 240Pu. The ratios of ²³⁶U/¹³⁷Cs and ²³⁶U/^239 + 240Pu were (4.10 ± 0.12) × 10⁹ and (1.26 ± 0.04) × 10¹¹ atoms Bq^− 1, respectively. Results of ²³⁶U, ¹³⁷Cs and ^239 + 240Pu measurements for the seven soil cores (0-30 cm) from Hiroshima were discussed on the basis of ratios of ²³⁶U/¹³⁷Cs and ²³⁶U/^239 + 240Pu by comparing with those from the background area in Ishikawa, indicating that the global fallout dominates the current level of ²³⁶U accumulation in soil in the Black-rain area around Hiroshima after the Hiroshima bomb, and the contribution of the close-in fallout ²³⁶U produced by the Hiroshima A-bomb seems difficult to observe.     

Miscibility in binary blends of aromatic and alicyclic polyamides

Miscibility was studied for four polyamide blends of 6I/6T [copolymer consisting of 1,6‐hexamethylene diamine and isophthalic acid (6I) (70 wt %) and terephthalic acid (6T) (30 wt %)] with MXD6 (polyamide of m‐xylenediamine and adipic acid), BAC6 (polyamide of 1,3‐bis(aminomethyl)cyclohexane and adipic acid), TR55 (copolymer consisting of nylon 11 (30 wt %), and polyamide of bis(3‐methyl, 4‐aminocyclohexyl)methane (30 wt %) and isophthalic acid (70 wt %), and CX7323 (polyamide of bis(4‐aminocyclohexyl)methane and dodecanedicarboxylic acid), using differential scanning calorimetry, X‐ray diffraction method, and electronmicroscopic observation. In quenched MXD6/(6I/6T) and BAC6/(6I/6T) blends, MXD6 and BAC6 components were miscible to 6I/6T, but TR55 and CX7323 components were completely phase‐separated from 6I/6T. Interestingly on electronmicroscopic observations, TR55 and CX7323 components were seen as droplets in 6I/6T medium when the content is low, but when 50 wt %, a layered structure was constructed with 6I/6T, reminiscent of morphological structure in block copolymer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3971–3978, 2006     

Cationic copolymerization behavior of a bicyclic orthoester having hydroxy group with glycidyl phenyl ether and volume change on their copolymerization

This article describes cationic ring‐opening copolymerization of a bicyclic orthoester having hydroxy group (BOE‐OH) and glycidyl phenyl ether (GPE), and the volume shrinkage behavior during the copolymerization. THF soluble polyethers [poly(BOE‐OH‐co‐GPE)] were obtained by the copolymerizations at 80–180°C, while crosslinked poly(BOE‐OH‐co‐GPE) was obtained by the copolymerizations at 220–250°C. This crosslinking reaction may originate from the dehydration of methylol groups in the side chain of poly(BOE‐OH‐co‐GPE). The volume shrinkage during the cationic copolymerization reduced as the increase of the BOE‐OH feed ratio. By contrast, the volume shrinkage on the crosslinking polymerization was almost independent on the BOE‐OH feed ratio. Poly(BOE‐OH‐co‐GPE)s with higher BOE‐OH composition showed lower thermal weight loss temperature owing to the release of H₂O by dehydration of methylol groups. The BOE‐OH component in the THF soluble poly(BOE‐OH‐co‐GPE)s lowered the glass transition temperature (T_g), while that in the crosslinked poly(BOE‐OH‐co‐GPE) increased the T_g probably because of the higher crosslinking density. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1356–1361, 2006     

Polymeric phosphonium salts as a novel class of cationic biocides. VII. Synthesis and antibacterial activity of polymeric phosphonium salts and their model compounds containing long alkyl chains

Various polymeric phosphonium salts containing long alkyl chains (C₁₀? C₁₈) and their corresponding model compounds were prepared, which possess the same hydrophobic structure as that of the common disinfectants (quaternary ammonium salts), and their antibacterial activities were evaluated by means of the viable cell counting method against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative). The polymer with the decyl group exhibited a higher activity than that of the corresponding model compound, particularly against the Gram-positive strain. Furthermore, antibacterial activity of the polymers was found to decrease as the chain length increased. In contrast with the polymers, the antibacterial activity of the corresponding model compounds increased as hydrophobicity of the substituents increased. The antibacterial activity was strongly dependent on the structure, particularly on the length of the alkyl chain. © 1994 John Wiley & Sons, Inc.     

Enhancement of low density lipoprotein binding to both low density lipoprotein receptor-positive and- negative cells by tetracycline antibiotics

Some tetracycline (TC) antibiotics, including TC and anhydrotetracycline, have been found to enhance specific binding of low density lipoprotein (LDL) to both LDL receptor-positive and-negative cells at relatively higher concentrations. When incubated at 37°C, the ability of LDL receptor-negative human fibroblasts to bind ¹²⁵I-LDL was increased from<2 to 45 ng/mg by 170 μM TC. In normal human fibroblasts and Hep G2 cells, ¹²⁵I-LDL binding was elevated 1.4- to 2-fold by 113 μM TC. The ¹²⁵I-LDL binding in the presence of TC was diminished by both heparin and EDTA. The enhancement by TC was not observed when ¹²⁵I-LDL binding was assayed at 4°C. TC enhanced LDL binding to paraformaldehyde-fixed Hep G2 cells, excluding LDL receptor induction in the mechanism. These results demonstrated that TC enhanced cellular LDL binding through a process not involving functional LDL receptors.     

External doses in the environment from the Tokai-mura criticality accident

On 30 September 1999, a criticality accident occurred at a uranium processing plant operated by JCO in Tokai-mura, Japan and the criticality remained for about 20 h. Almost all doses to the neighbouring residents were brought by neutrons and gamma rays emitted from the facility rather than fission products released to the environment. External doses in the environment were evaluated using radiation monitoring data and radiation transport calculation. A pattern of the dose rate evolution was modelled based on the records of gamma ray monitors in the JCO facilities. Relations between the ambient dose equivalent rates of neutrons/gamma rays and the distance from the facility were determined from the monitoring data obtained around the accident site. Conversion from the ambient dose equivalent to the effective dose equivalent was made assuming the energy spectra calculated by the radiation transport code, ANISN. It was estimated that the people who stayed outside the 350 m zone would receive doses of less than 1 mSv.