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Daisuke Tahara Ryou Hatano Hozi Iwatani Yasunori Koya Youichi Hayakawa 《Ichthyological Research》2010,57(1):62-70
Annual changes in testicular development and occurrence of parasperm were investigated using 2-year-old male fourspine sculpins
Cottus kazika, based on the histological observation of testes. The male reproductive organ of fourspine sculpins comprised a pair of testes
and a sperm duct that functioned as a sperm-storage organ. Male maturity was divided into the following periods: spermatogonial
proliferation period (September), early spermatogenic period (October), mid-spermatogenic period (November), late spermatogenic
period (December and January), functional maturation period (February and March), and recovery period (April to August). Spermatogenesis
rapidly progressed from October to January and continued until the functional maturation period. Parasperm formation, which
is known in some cottidae species, was observed in fourspine sculpins. Testicular regression of cultured fourspine sculpins
progressed slowly during the recovery period when residual parasperm and empty spaces occupied the testis. The parasperm were
immotile and oval and slightly concave on one side; additionally, they stained strongly with hematoxylin and PAS. Seminal
lobules of the testis were filled with parasperm during the spawning period; in contrast, the sperm duct was filled with eusperm.
These findings were observed in both cultured and wild fish. In this study, the functions of parasperm with regard to reproduction
in fourspine sculpins are discussed. 相似文献
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Hideaki Kobayashi Ryou Sasahara Shoichi Yoda 《Bioscience, biotechnology, and biochemistry》2017,81(6):1206-1215
The flavor deterioration of mayonnaise is induced by iron, which is released from egg yolk phosvitin under acidic conditions and promotes lipid oxidation. To prevent oxidative deterioration, natural components, rather than synthetic chemicals such as ethylenediaminetetraacetic acid have been required by consumers. In the present study, we evaluated the inhibitory effects of three egg white components with the same amino acid composition, namely egg white protein, hydrolysate, and the amino acid mixture, on lipid oxidation in mayonnaise and an acidic egg yolk solution as a model system. We found that the hydrolysate had the strongest inhibitory effect on lipid oxidation among the three components. The mechanism underlying the antioxidant effect was associated with Fe2+-chelating activity. Thus, egg white hydrolysate may have the potential as natural inhibitors of lipid oxidation in mayonnaise. 相似文献
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