448 research outputs found
Porcine oocyte maturation in vitro : role of cAMP and oocyte-secreted factors: a practical approach
Polyspermy or the penetration of more than one sperm cell remains a problem during porcine in vitro fertilization (IVF). After in vitro culture of porcine zygotes, only a low percentage of blastocysts develop and their quality is inferior to that of in vivo derived blastocysts. It is unknown whether the cytoplasmic maturation of the oocyte is sufficiently sustained in current in vitro maturation (IVM) procedures. The complex interplay between oocyte and cumulus cells during IVM is a key factor in this process. By focusing on this bidirectional communication, it is possible to control the coordination of cumulus expansion, and nuclear and cytoplasmic maturation during IVM to some extent. Therefore, this review focuses on the regulatory mechanisms between oocytes and cumulus cells to further the development of new in vitro embryo production (IVP) procedures, resulting in less polyspermy and improved oocyte developmental potential. Specifically, we focused on the involvement of cAMP in maturation regulation and function of oocyte-secreted factors (OSFs) in the bidirectional regulatory loop between oocyte and cumulus cells. Our studies suggest that maintaining high cAMP levels in the oocyte during the first half of IVM sustained improved oocyte maturation, resulting in an enhanced response after IVF and cumulus matrix disassembly. Recent research indicated that the addition of OSFs during IVM enhanced the developmental competence of small follicle-derived oocytes, which was stimulated by epidermal growth factor (EGF) via developing EGF-receptor signaling
東北文化研究センターの取り組み
第1回文化遺産学交流会(関西大学なにわ・大阪文化遺産学研究センター、2008年10月17日)補助事業 文部科学省私立大学学術研究高度化推進事業オープン・リサーチ・センター整備事業(平成17年度~平成21年度)なにわ・大阪文化遺産の総合人文学的研
ベニバナ エマキ オ ヨム
This English version is prepared by Masanobu Hayakawa (Emerius Professor, Yamagata University) 「「紅花絵巻」を読む」(東北芸術工科大学東北文化研究センター「東アジアのなかの日本文化に関する総合的な研究 プロジェクト1: 東アジアの民俗文化にかかわる調査・研究とデータベース化 平成14年度~平成18年度私立大学学術研究高度化推進事業「オープン・リサーチ・センター整備事業」研究成果報告書 最上川文化研究」2007.3.27 p.97 - 114 掲載論文)の英語訳(30p ; 30cm
Developmental Competence of Early Stage Porcine Embryos Cultured in Medium with Different Energy Substrate in vitro
To elucidate the effect of energy requirement during the early embryonic development on their developmental ability to develop to blastocyst stage, in vitro fertilized (IVF) porcine one-cell embryos were cultured in modified North Carolina State University (NCSU)-37 supplemented with different energy substrate. Result indicated that the cleavage rate of embryos in Pyr-Lac and Gluc-Pyr-Lact groups was significantly higher than in those in Gluc group and Gluc-Rib group (P < 0.05). At Day 6 of culture, the highest proportion of embryos develop to the blastocyst stage was obtained in the presence of pyruvate-lactate only. In the medium with glucose, the addition of pyruvate-lactate or ribose slightly increased the proportion of embryos develop to the blastocyst stage, however the value were not significantly different form those obtained in the presence of glucose only. The mean cell number in blastocysts derived from Pyr-Lac and Gluc-Pyr-Lact groups were significantly higher than those in the Gluc group (P < 0.05). These results indicated that the presence of glucose only, as energy substrate, during the first 2 days of in vitro culture (IVC) caused a decrease in development of in vitro produced (IVP) porcine embryos to the blastocyst stage and mean cell number in blastocysts
Solution-processed n-type organic thin-film transistors with high field-effect mobility
We report the performance of solution-processed n-type organic thin-film transistors (OTFTs) based on C60 derivatives. Long-chain alkyl-substituted C60, C60-fused N-methylpyrrolidine-meta-C12 phenyl (C60MC12), was used as a semiconducting layer. The C60MC12-thin-film transistor shows high electron mobility of 0.067 cm2/V s in saturation regime. From the result of x-ray diffraction analysis, the C60MC12 active layer forms highly ordered crystalline film. We found that self-assemble ability of long alkyl chains plays an important role for fabrication of highly ordered crystalline film, leading to achievement of high electron mobility in solution-processed n-type OTFTs
Design of Heat-Activated Reversible Integral Attachments for Product-Embedded Disassembly
Disassembly is a fundamental process needed for component reuse and material recycling in all assembled products. Integral attachments, also known as snap" fits, are favored fastening means in design for assembly (DFA) methodologies, but are not necessarily a favored choice for design for disassembly. Several prototype designs of a new class of integral attachments are presented, where the snapped joints can be disengaged by the application of localized heat sources. The design problem of reversible integral attachments is posed as the optimization of compliant mechanisms actuated with localized thermal expansion of materials. The Homogenization Design Method is utilized to obtain an optimal structural topology that realizes a desired deformation of snapped features for joint release. The obtained optimal topologies are simplified to enhance the manufacturability for the conventional injection molding technologies. Results of the example designs are verified by finite element analysesPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87259/4/Saitou101.pd
Solution-processed n-type organic thin-film transistors with high field-effect mobility
We report the performance of solution-processed n-type organic thin-film transistors (OTFTs) based on C60 derivatives. Long-chain alkyl-substituted C60, C60-fused N-methylpyrrolidine-meta-C12 phenyl (C60MC12), was used as a semiconducting layer. The C60MC12-thin-film transistor shows high electron mobility of 0.067 cm2/V s in saturation regime. From the result of x-ray diffraction analysis, the C60MC12 active layer forms highly ordered crystalline film. We found that self-assemble ability of long alkyl chains plays an important role for fabrication of highly ordered crystalline film, leading to achievement of high electron mobility in solution-processed n-type OTFTs
Clinical impact of bladder biopsies with TUR-BT according to cytology results in patients with bladder cancer: a case control study
<p>Abstract</p> <p>Background</p> <p>There seems to be no consensus concerning taking bladder biopsies during transurethral resection of bladder tumor (TUR-BT). We investigate the clinical significance of bladder biopsy with TUR-BT and the relationship between urinary cytology and the biopsy results.</p> <p>Methods</p> <p>We reviewed a total of 424 patients with non-muscle invasive bladder cancer treated with TUR-BT between 1998 and 2005. Of the total, 293 patients also underwent a bladder biopsy. Biopsies from suspicious-appearing urothelium (N = 59) and those from normal-appearing urothelium (N = 234) were evaluated separately.</p> <p>Results</p> <p>Bladder cancer was observed in 23 cases (39.0%) who underwent a biopsy of suspicious-appearing urothelium. Among these 23 cases, 9 cases with visible tumor resection had carcinoma in situ (CIS) only in the biopsies from suspicious-appearing urothelium. Urinary cytology was negative in 3 of the 9 cases. Bladder cancer was observed in 26 cases (11.1%) who underwent a biopsy of normal-appearing urothelium. Of them, 5 cases with visible tumors had CIS only in the multiple biopsies from normal-appearing urothelium. Urinary cytology was positive in all of the 5 cases. No upstaging or upgrading cases were found in these patients by the addition of these two types of biopsy. Furthermore, therapy was not altered in these patients. With or without bladder biopsy was not a significant factor for tumor recurrence in either the univariate or multivariate analysis.</p> <p>Conclusions</p> <p>Based on the results, it is concluded the multiple biopsies from normal-appearing urothelium are not necessary in patients with negative cytology results because of the low detection rate and lack of influence on therapeutic decisions. Meanwhile, biopsy of suspicious-appearing urothelium is needed in patients with negative cytology results in order to detect CIS due to staging properties. This result supports a recent EAU guideline.</p
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