Synthesis of syndiotactic poly(methacrylic acid) by free‐radical polymerization of the pseudo‐divinyl monomer formed with methacrylic acid and catechol

Syndiotactic poly(methacrylic acid) (Syn‐PMAA, r diad = 91 mol %) was synthesized by free radical polymerization of methacrylic acid (MAA) with catechol. The pseudo‐divinyl monomer was formed with one catechol and two MAA molecules by the hydrogen bonding between OH groups of catechol and COOH group of MAA. When the free radical polymerization of the pseudo‐divinyl monomer was carried out, intra‐ and intermolecular addition proceeded with racemic addition. The hydrogen bonding was the driving force to control tacticity. We discussed the effects of solvent, temperature, and the concentrations of MAA and catechol on the pseudo‐divinyl monomer formation. The highly syndiotactic PMAA was successfully obtained. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Determination of brominated flame retardants and brominated dioxins in fish collected from three regions of Japan

The concentrations of brominated dioxins which are polybrominated dibenzo-p-dioxins/polybrominated dibenzofurans (PBDD/DFs) and mono-bromo polychlorinated dibenzo-p-dioxins/dibenzofurans, polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A (TBBPA) were investigated in a total of 45 fish samples collected from three regions in Japan. In the brominated dioxins, 1,2,3,4,6,7,8-heptabromodibenzofuran (HpBDF) was the most abundant congener, and it was found in seven fish samples at 0.10-25.6 pg/g wet weight (ww). The highest concentration of 1,2,3,4,6,7,8-HpBDF was found in the pike eel. Regarding other congeners, 2,3,7,8-tetrabromodibenzo-p-dioxin was detected in the sea bream at 0.02 pg/g ww, and 2,3,7,8-tetrabromodibenzofuran was detected in the conger eel at 0.03 pg/g ww. 3-Bromo-2,7,8-trichlorodibenzofuran was detected in the Sardinella zunasi and the conger eel at 0.01 pg/g ww and 0.02 pg/g ww, respectively. Using toxic equivalency factors of chlorinated dioxins, we calculated the PBDD/DFs concentrations of these fish samples at 0.001-0.256 pg TEQ/g ww. PBDEs were detected in all of the fish samples. The concentrations of total PBDEs were 0.01-2.88 ng/g ww. The seerfish and the yellowtail containd PBDEs in high concentrations. The most dominant congener in most of the fish was 2,2',4,4'-tetrabromo diphenyl ether. TBBPA was detected in 29 fish samples at 0.01-0.11 ng/g ww. The mean level of TBBPA was about one-tenth or less of the total level of PBDEs. A good correlation was obtained between total PBDEs and fat content. On the other hand, no correlation was obtained between TBBPA and fat content. The daily intakes from fish were estimated to be 0.58 ng/kg body weight (bw)/day for total PBDEs, 0.03 ng/kg bw/day for TBBPA, and 0.01 pg TEQ/kg bw/day for brominated dioxins in the case assuming that the average bw of a Japanese adult person is 50 kg and that the average fish consumption is 82 g/day. For PBDEs, the provisionally calculated value was much less than the lowest observed adverse effect level value (1 mg/kg bw/day). For brominated dioxins, the daily intake was at a very low level compared with the Japanese daily intake of polychlorinated dioxins from fish. Even if the value of PBDD/DFs is added to the amount of chlorinated dioxin exposure, it was estimated that it is less than the tolerable daily intake (4 pg TEQ/kg bw/day) in Japan.     

Synthesis of poly(vinyl alcohol) core-polystyrene shell-type flower microgels

Four types of poly(vinyl alcohol-b-styrene-b-vinyl alcohol) (P(VA-b-S-b-VA)) triblock copolymers were synthesized by hydrolysis of poly(vinyl acetate-b-styrene-b-vinyl acetate) triblock copolymers prepared by radical living polymerization. The polyvinyl alcohol (PVA) core-polystyrene corona-type flower micelles were formed with ASA-4 in benzene at 25°C. The PVA core part of the micelle was crosslinked with hexamethylene diisocyanate in solution. The monodispersed spherical products (microspheres) were synthesized by crosslinking. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 849–854, 1997     

Changes in dyeability and morphology of cotton fiber subjected to cellulase treatment

Unprocessed and mercerized cotton fibers were treated with commercial crude cellulase. The changes in the dyeability and structural features of the fiber due to cellulase treatment were studied. The dyeability was examined in terms of uptake of three reactive dyes and the apparent affinity of Congo Red to cotton fiber. The dyeability of the unprocessed fiber was assumed to be influenced by some impurities present in it. This fiber probably resembled polynosic fiber in molecular aggregate at a certain stage of hydrolysis. Mercerized cotton showed a similar pattern in dyeability as weight loss increased, regardless of dye species. Enzyme more easily penetrated the mercerized fiber than the unprocessed fiber. Cellulase treatment influenced the X-ray crystalline reflection pattern for the mercerized fiber but nominally influenced that for unprocessed fiber. Scanning electron micrographs revealed that cellulase treatment caused swelling of the fibrils. They also revealed that the disordered regions between the fibrils in the secondary walls were removed at low weight loss for the unprocessed fiber. The mercerized fiber at high weight loss had large cracks oblique to the fiber axis and showed no individual fibrils in the secondary wall. The primary wall was removed in the initial stage of hydrolysis for both the unprocessed and mercerized fibers. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 155–164, 1997     

Synthesis of core–shell type microsphere with reactive seed microspheres

Monodispersed poly(methyl methacrylate) (PMMA) particles (seed microspheres) were synthesized with the living radical initiators, tetramethylthiuram disulfide, or p-xylene dimethyldithiocarbamate by suspension polymerization in water media with and without divinyl benzene as a crosslinker. Monodispersed spherical microspheres with PMMA core–polyacrylamide shells were synthesized by UV irradiation to the seed microsphere–acrylamide aqueous solution. The content and the molecular weight of the polyacrylamide shell chain were controlled by changing the acrylamide feed and irradiation time of the UV light. The microspheres became dispersible to water after the UV irradiation. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 211–216, 1998     

Immunological Properties of Atopic Dermatitis-Associated Alopecia Areata

Alopecia areata (AA) is regarded as a tissue-specific and cell-mediated autoimmune disorder. Regarding the cytokine balance, AA has been considered a type 1 inflammatory disease. On the other hand, AA often complicates atopic dermatitis (AD) and AD is regarded as type 2 inflammatory disease. However, the immunological aspects of AA in relation to AD are still poorly understood. Therefore, we aim to clarify the immunological properties of AD-associated AA. In this study, we performed comparative analysis of the expression of intracytoplasmic cytokines (IFN-γ, IL-4, and IL-13), chemokine receptors (CXCR3 and CCR4) in peripheral blood which were taken from healthy controls, non-atopic AA patients, AA patients with extrinsic AD, and AA patients with intrinsic AD by flowcytometric analysis. We also compared the scalp skin samples taken from AA patients with extrinsic AD before and after treatment with dupilumab. In non-atopic AA patients, the ratios of CD4+IFN-γ+ cells to CD4⁺IL-4⁺ cells and CD4⁺IFN-γ⁺ cells to CD4⁺IL-13⁺ cells were higher than those in AA patients with extrinsic AD. Meanwhile, the ratio of CD8⁺IFN-γ⁺ cells to CD8+IL-13+ cells was significantly higher in the non-atopic AA than in the healthy controls. In AA patients with extrinsic AD, the skin AA lesion showed dense infiltration of not only CXCR3+ cells but also CCR4⁺ cells around hair bulb before dupilumab treatment. However, after the treatment, the number of CXCR3⁺ cells had no remarkable change while the number of CCR4⁺ cells significantly decreased. These results indicate that the immunological condition of AA may be different between atopic and non-atopic patients and between extrinsic and intrinsic AD patients. Our study provides an important notion that type 2 immunity may participate in the development of AA in extrinsic AD patients. It may be considered that the immunological state of non-atopic AA is different from that of atopic AA.     

Laboratory testing for evaluation of the influence of a small degree of internal erosion on deformation and stiffness

Suffusion is a type of internal erosion, namely, the transportation of soil driven by the seepage force of finer fractions within coarser fractions. The present work uses triaxial confining compression tests to study how a small degree of suffusion affects soil stiffness and deformation. This approach allows the suffusion inside a specimen to impose a downward seepage flow. Although a small degree of suffusion is not detectable, it can lead to the deterioration of earth structures. Linear displacement transducers and clip gages were attached to specimens to accurately measure the localized strain rates. In addition, the turbidity of the discharged water was evaluated. Following the downward seepage, each drained specimen was monotonically compressed. The experimental results show that cohesive soil undergoes suffusion and that most of the clay fractions bonding the sand particles erode. At intermediate strain, the deviator stress decreases in proportion to the degree of suffusion, but this decrease ceases at the critical state. Anisotropic behavior is observed and is tentatively attributed to the disruption of the soil texture, which is qualitatively monitored by scanning electron microscopy. Finally, a simple formula is proposed for evaluating the decrease in stiffness due to suffusion.     

The effect of a noise plane on discrimination of mirror symmetry in a different depth plane.

Participants were asked to discriminate between 100% and 50% symmetrical dot patterns (the target plane), both of which were overlaid in depth by a random-dot plane (the noise plane). The results showed that noise in the different depth plane was effectively excluded when the relative binocular disparities between 2 planes were large (8' or more), the target plane was presented in front of the noise plane, and the stimulus duration was long. A simple model based on a grouping process in depth and on a masking effect was applied to the data. The results of application of the model suggest that the visual system uses the output of the grouping process to discriminate 2-dimensional symmetry in 3-D noise. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Application of a qualitative and quantitative real-time polymerase chain reaction method for detecting genetically modified papaya line 55-1 in papaya products

Genetically modified (GM) papaya (Carica papaya L.) line 55-1 (55-1), which is resistant to papaya ringspot virus infection, has been marketed internationally. Many countries have mandatory labeling regulations for GM foods, and there is a need for specific methods for detecting 55-1. Here, an event- and construct-specific real-time polymerase chain reaction (PCR) method was developed for detecting 55-1 in papaya products. Quantitative detection was possible for fresh papaya fruit up to dilutions of 0.001% and 0.01% (weight per weight [w/w]) for homozygous SunUp and heterozygous Rainbow cultivars, respectively, in non-GM papaya. The limit of detection and quantification was as low as 250 copies of the haploid genome according to a standard reference plasmid. The method was applicable to qualitative detection of 55-1 in eight types of processed products (canned papaya, pickled papaya, dried fruit, papaya-leaf tea, jam, puree, juice, and frozen dessert) containing papaya as a main ingredient.     

Stable Delocalized Singlet Biradical Hydrocarbon for Organic Field‐Effect Transistors

Delocalized singlet biradical hydrocarbons hold promise as new semiconducting materials for high‐performance organic devices. However, to date biradical organic molecules have attracted little attention as a material for organic electronic devices. Here, this work shows that films of a crystallized diphenyl derivative of s‐indacenodiphenalene (Ph₂‐IDPL) exhibit high ambipolar mobilities in organic field‐effect transistors (OFETs). Furthermore, OFETs fabricated using Ph₂‐IDPL single crystals show high hole mobility (μ_h = 7.2 × 10^?1 cm² V^?1 s^?1) comparable to that of amorphous Si. Additionally, high on/off ratios are achieved for Ph₂‐IDPL by inserting self‐assembled mono­layer of alkanethiol between the semiconducting layer and the Au electrodes. These findings open a door to the application of ambipolar OFETs to organic electronics such as complementary metal oxide semiconductor logic circuits.