• Applied Microscopy
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• v.34 no.1
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• pp.71-81
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• 2004

When U. unicinctus mature oocytes were fertilized in vitro, germinal vesicle breakdown (GVBD) and meioses occurred and the zygotes entered cleavage stage. A modified pattern of spiral cleavages, suggestively based on behavior of mitotic spindles, have been observed in this work. The first and second cleavages were meridional and the third was equatorial, and then followed by repetitions of meridional-equatorial cleavage. The cleavage of the isolecithal egg were equal and holoblastic and its patterns were spiral. The anti-${\alpha}-,-{\beta}$- tubulin reactions and confocal microscopy revealed mitotic apparates tilted obliquely at each mitosis causing oblique displacements of the blastomeres. Despite isolecithal distribution of yolk, this observations implicated that tilting of mitotic apparates induced spiral cleavage and the displacements of blastomeres. However, these features would not be the typical spiral cleavage, but represented a modified pattern of known Spiralian s in the sense of the equal cleavage. During the first cleavage, heart-shaped eggs have been produced. Electron microscopies exhibited the first cleavage furrow extended with its membranous structure deeply into the cytoplasm. Contractile ring has not been observed.

• Archives of Pharmacal Research
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• v.22 no.4
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• pp.398-400
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• 1999

Sufentanil, a potent anilidopiperidine analgesic, was synthesized from a simple thiophenylethylamine via six sequence. The key parts of this synthesis involved an efficient construction of thiophenylethylpiperidone by aminomethano desilylation-cyclization followed by Swern oxidation and a direct regioselective N-nucleophilic spiral epoxide cleavage with aniline promoted by Lewis acids.

• The Korean Journal of Malacology
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• v.30 no.4
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• pp.311-319
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• 2014

Early sexual maturation through temperature stimulation was induced in female and male of yezo scallop. Gonadosomatic index (GSI) in female showed $9.12{\pm}2.9$ in January, $14.89{\pm}2.9$ in February and $21.3{\pm}1.4$ in March in experiment I. GSI in experiment I showed a significant increase (P < 0.05) and in experiments II and III were not show significant variations (P > 0.05). It also showed significant between the control and the experiments I, II, and III in February (P < 0.05) measurements. Experiment I has showed good results in sexual maturation and spawning when compared with other experiments II and III and the control. Histological observation showed that ovary condition was in a growing stage in all the experiments I, II, and III. In February, ovary condition through histological observation was a late mature stage in all the experiments I, II, and III except the control of a growing stage. GSI and gonad weight were $4.4{\pm}0.88$ and 2.8 g, respectively in November whereas it was $15.1{\pm}2.8$, and 11.7 g, respectively in January and $21.7{\pm}5.4$, and 19.4 g, respectively in February after rearing at a water bath of $12^{\circ}C$ depending on the condition of experiment I. It was possible early releasing of eggs and sperms of yezo scallop in February instead of the middle of April to the end of May being spawning period. Fertilized eggs have become a gastrula stage through a spiral cleavage and then become a trochophore larvae after 36 hours. After 10 days, D-shaped larvae have changed into an umbo stage larvae and attached to juveniles in the post larvae after 20-23 days.