Mesophase structure discovered through in-situ X-ray measurement in drawing process of poly(ethylene 2,6-naphthalene dicarboxylate) fiber

The structure development in the continuous laser-heated drawing process of poly(ethylene 2,6-naphthalene dicarboxylate) (PEN) fiber was analyzed by in-situ X-ray diffraction measurement. Because of the rapid and uniform laser heating, and the resultant steady-state nature of the necking-drawing, the structure development after the on-set of necking could be measured in the time resolution of several hundred microseconds. We found for the first time the temporal appearance of meridional (001') diffraction at several milliseconds after the on-set of necking indicating that the mesophase structure similar to the one reported for poly(ethylene terephthalate) was also formed in the initial stage of fiber structure development of PEN. The d-spacing of the (001') diffraction 1.230 +/- 0.003 nm was shorter than the c-axis lengths of both alpha and beta crystals.ArticlePOLYMER. 50(19):4429-4431 (2009)journal articl

Effect of drawing stress on mesophase structure formation of poly(ethylene 2,6-naphthalene dicarboxylate) fiber just after the neck-drawing point

The structural development of poly(ethylene 2,6-naphthalene dicarboxylate) (PEN) fibers was analyzed by in situ X-ray diffraction and fiber temperature measurements. The PEN fiber was drawn continuously under three drawing stresses, where the neck-drawing point was fixed accurately by CO2 laser irradiation heating. The developed crystal structures of the drawn fibers depended on the drawing stresses, that is, only the alpha-crystal was obtained under a drawing stress of 148 MPa, an alpha-rich mixed crystal was obtained for 54 MPa, and a beta-rich mixed crystal was obtained under 23 MPa stress. Fiber containing over 70% beta-crystal was obtained in the third case. Orientation-induced crystallization rates (K) and crystallization induction times (t(0)) were estimated for the three drawing stresses: K = 2210 s(-1) and t(0) = 0.5 ms for 148 MPa, K = 940 s(-1) and t(0) = 1.0 ms for 54 MPa, and K= 655 s(-1) and t(0) = 4.0 ms for 23 MPa. In addition, the drawing stress acted as a definitive influence not only on the resulting crystal form but also on the chain conformation of the mesophase structure. The d-spacing of the (001') diffraction increased with drawing stress, and the longer (001') spacing generated the alpha-crystal while the comparatively shorter (001') spacing yielded the beta-crystal. The d-spacings of 1.27 and 1.23 nm for the drawing stresses of 148 and 23 MPa, respectively, were somewhat shorter than the c-axis lengths of the alpha- and beta-crystals of 1.32 and 1.27 nm, respectively.ArticlePOLYMER. 53(19):4272-4279 (2012)journal articl

On Nietzsche’s Concept of ‘European Nihilism’

<div><p>Aplog-1 is a simplified analog of the tumor-promoting aplysiatoxin with anti-proliferative and cytotoxic activities against several cancer cell lines. Our recent findings have suggested that protein kinase Cδ (PKCδ) could be one of the target proteins of aplog-1. In this study, we synthesized amide-aplog-1 (<b>3</b>), in which the C-1 ester group was replaced with an amide group, to improve chemical stability <i>in vivo</i>. Unfortunately, <b>3</b> exhibited seventy-fold weaker binding affinity to the C1B domain of PKCδ than that of aplog-1, and negligible anti-proliferative and cytotoxic activities even at 10⁻⁴ M. A conformational analysis and density functional theory calculations indicated that the stable conformation of <b>3</b> differed from that of aplog-1. Since 27-methyl and 27-methoxy derivatives (<b>1</b>, <b>2</b>) without the ability to bind to PKC isozymes exhibited marked anti-proliferative and cytotoxic activities at 10⁻⁴ M, <b>3</b> may be an inactive control to identify the target proteins of aplogs.</p></div

Induction of Gynogenetic Diploids in Ocellated Puffer Takifugu rubripes by Cold and Heat Treatments

トラフグ Takifugu rubripes の卵に紫外線照射精子を媒精すると、雌性発生半数体が生じるが、これらは奇形で生存できなかった。そこで、受精後5分あるいは30分に0℃、45分間の低温処理あるいは30℃、5分間の高温処理を卵に加えたところ、生存性の雌性発生二倍体が得られた。これらの魚のアコニット酸ヒドラターゼ(AH)とイソクヱン酸脱水素酵素(IDHP)について電気泳動分析を行ったところ、各酵素支配遺伝子座において二種類のホモ接合遺伝子型の他、遣伝子-動原体間組換えによるヘテロ接合遺伝子型が見られた。従って、得られた雌性発生二倍体は、第二極体放出阻止により倍化したものと判断される。対照の雌雄比がほぼ1:1であるのに対し、雌性発生魚の93%が雌であったことから、トラフグは雄性ヘテロ(XX-XY)型と考えられるが、雄の出現要因については現状では明かではない。Fertilization with UV irradiated spermatozoa induced inviable gynogenetic haploid development in ocellated puffer Takifugu rubripes. Cold treatment (0°C, 45 min duration) initiated 5 and 30 min after fertilization with UV irradiated spermatozoa gave viable gynogenetic diploid progeny. Heat treatment (30°C, 5 min duration) from 5 min after fertilization also produced viable diploid gynogens. Since the resultant fish showed a heterozygous genotype which occurred by gene-centromere recombination as well as two homozygous genotypes at aconitate hydratase or isocitrate dehydrogenase isozyme coding locus, they were considered diploid gynogens which were produced by inhibition of the second polar body extrusion. Control progeny exhibited 1 : 1 sex ratio between females and males, while 93% of the gynogens were female. This result suggests that this species has basically XX-XY sex determination system

Production of Gynogenetic Diploids by Temperature and Pressure Treatments and Sex Reversal by Immersion in Methyltestosterone in Marbled Sole Limanda yokohamae

マコガレイ Limanda yokohamae における雌性発生二倍体作出のための温度、圧力処理諸条件ならびに遺伝的雌の雄化のための17α-メチルテストステロン浸漬処理条件について検討した。本種の卵を紫外線照射精子で受精すると、致死性の雌性発生単数体が生じるが、受精後5分に、低温(-2.0～-0.8℃、60分間)、高温(39℃、5分間)あるいは圧力処理(700kg/cm2、6分間)を施すと、比較的高率で生存性の個体が得られた。これらはPGM*あるいはIDHP*アイソザイム遺伝子座において、遺伝子-動原体間の組換えにより生じるヘテロ接合遺伝子型と二種類の非組換え型ホモ接合遺伝子型を示すことから、第二極鉢放出阻止により倍数化した雌性発生二倍体と判断された。UV精子受精後165-205分に低温処理を行った区では正常仔魚は得られなかったが、受精後175-205分に圧力処理を施した区では少数の正常個体が得られた。アイソザイム分析の結果、これらの中に、第一卵割阻止型完全ホモ接合雌性発生二倍体が存在することが示唆された。14ヶ月飼育した通常二倍体の雌雄間で体重、体長を比較したところ有意に雌が大きかった。しかし、雌性発生二倍体雌は通常二倍体雌に比較すると有意に小さかった。雌性発生二倍体は調査したすべての個体で雌であった。孵化後21-80日目まで雌性発生仔魚を17α-メチルテストステロンで浸漬処理したところ、濃度が高いほど性転換雄の出現率が高く、1、5、10、20μg/ℓの区で、それぞれ53、60、73、80%であった。This study was made to optimize treating conditions of eggs for producing gynogenetic diploids as well as to determine optimal methyltestosterone concentration for sex reversal of fry from genetic females to functional males in marbled sole Limanda yokohamae. Cold (-2.0 ~ -0.8°C for 60 min duration), heat (30°C for 5 min duration) and hydrostatic pressure treatments (700 kg/cm2 for 6 min duration) initiated 5 min after fertilization with genetically inactivated spermatozoa which had been irradiated with UV rays, gave relatively high frequencies of viable progeny. The resultant fish exhibited a heterozygous genotype which occurred by gene-centromere recombination and two unrecombinant homozygous genotypes at PGM* or IDHP* isozyme-coding locus, indicative of duplication of maternal chromosomes by inhibition of the second polar body extrustion. No viable fry was produced from the eggs subjected to cold shock at 165 to 205 min after fertilization. While, a small number of normal fish appeared in the groups treated with hydrostatic pressure at 175 to 205 min after fertilization. Isozyme analyses suggest presence of the complete homozygous gynogenetic diploids which were produced by inhibition of the first cleavage in these surviving fish. In normal diploid 14-month-old fish, females showed significantly better growth than males. However, gynogenetic diploids were significantly smaller than normal diploids. All the gynogenetic diploids examined were female. Immersion of the gynogenetic fry in 1, 5, 10 and 20 μg/ℓ of methyltestosterone between 21 and 80 days after hatching induced 53, 60, 73 and 80 percent of sex reversed males, respectively

Molecular cloning of cDNA encoding a 20S proteasome 2 subunit from goldfish (Carassius auratus) and its expression analysis

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