• Nuclear Engineering and Technology
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• v.48 no.2
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• pp.293-298
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• 2016

Thirty-eight spherules from the Antarctic ice sheet were analyzed using neutron activation analysis under two different conditions to investigate their origin. In almost all of these spherules, the contents of iron, cobalt, and manganese were determined to be 31% to 88%, 17 mg/kg to 810 mg/kg, and 0.017% to 7%, respectively. A detectable iridium content of 0.84 mg/kg was found in only one spherule, which was judged to be extraterrestrial in origin. A comparison of elemental compositions of the Antarctic spherules analyzed in this study with those of deep-sea sediment spherules and those of terrestrial materials revealed that most of the Antarctic spherules except for the sample in which iridium was detected could not be identified as extraterrestrial in origin.

• Korean journal of applied entomology
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• v.32 no.1
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• pp.90-100
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• 1993

Ultrastructure of the larval hemocytes in Sericinus montela Grey was observed with the transmission and scanning electron microscope. The 5 cell types, according to Breh lin and Zachary(1986), identified in the hemocytes of the last instar S. montela larva were; prohemocyte, plasmatocyte, granular cell, spherule cell and oenocytoid. Prohemocytes could be easily charaterized by a relatively large nucleus nd poorly developed cytoplasmic organelles. Plasmatocytes were relatively large spindle-shaped or oval cells with fibrous bundles. The spindle-shaped plasmatocytes, especially, were characterized by a well developed, elongated nucleus. Granular cells had various granules, either morphologically or in electron density, and highly developed cytoplasmic organelles in the cytoplasm. They had numerous cytoplasmic processes. Spherule cells were characterized by cytoplasmic spherules containing fine materials, which are released into the hemolymph upon maturity of the cell. Oenocytoids consisted of electron dense materials and the organelles in cytoplasm were poorly developed.

• The Korean Journal of Zoology
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• v.11 no.4
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• pp.103-117
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• 1968

Insect hemocytes during metamorphosis were studies by histchemical and autoradiographic methods is Pieris rapae (Lepidoptera). The hemocytes were classified into six types, prohemocytes, plasmatocytes, podocytes, granular hemocytes, spherule cells and oenocytoids on the basis of the transitions in shapes and inclnsions of cytoplasms. Proteins, nucleic acids, polysaccharides and lipids in the hemocytes were detected histochemically from larval to pupal stages to learn the rise and fall of them during growth and metamorphosis. Most of the granules consisted of glycogen, neutral mucopolysaccharides and mucoprotein in addition to some granules of neutral fats and phospholipids were found in the granular hemocytes and spherule cells. Mitotic figures and DNA synthetic activities were observed in every type of hemocytes from 2nd to 5th instars, suggesting the all types of hemocytes originated from the prohemocytes. The cytoplasmic filaments of plasmatocytes and pdocytes extended very long in prepupa and pupa and the vermiform cells were the transformed plasmatocytes due to their further differentiation.

• The Korean Journal of Zoology
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• v.38 no.3
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• pp.313-323
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• 1995

Ultrastructural characteristics of hemocytic differentiation pathway in Sericinus montetla Grey were observed with transmission electron microscope. Hemocytic differentiation took place in loose islets of hemopoietic organs as indicated by the presence of differentiating hemocytes; prohemocytes, plasmatocytes, granular cells and spherule cells. They are differentiatied from the stem cells through individual cell lineages. However, differentiating aspects of the oenocytoids were not observed. According to Brehelin and Zachary (1986), the premature hemocytes around the hemopoietic organs were classified into five types; prohemocytes, plasmatocytes, granular cells, spherule cells and oenocytoids.