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Biochemistry

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Journal of the Arkansas Academy of Science

1990

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Full-Text Articles in Life Sciences

Mermithid Nematodes: Sem Observations Comparing Hexamethyldisilazane And Critical Point Drying Methods, William R. Bowen, Christopher C. Hemann, Arthur A. Johnson, Barry H. Good Jan 1990

Mermithid Nematodes: Sem Observations Comparing Hexamethyldisilazane And Critical Point Drying Methods, William R. Bowen, Christopher C. Hemann, Arthur A. Johnson, Barry H. Good

Journal of the Arkansas Academy of Science

Morphological features of mermithid nematodes (Mermithidae) were studied with scanning electron microscopy, using hexamethyldisilazane-air drying in comparison with critical point drying via liquid carbon dioxide. Although general morphologic preservation of both HMDS-dried and CP-dried specimens was similar, structural features of the complex cuticle and internal organization were more easily resolved at higher magnifications in the HMDS-dried nematodes. These features include the superficial cuticular annulations, the fibrillar inner cuticle and peg-like microtrabeculae. The previously undescribed microtrabeculae are of special interest since they may facilitate an interaction of the mermithid (and perhaps nameatodes in general) musculature with its body wall that, at …


Conformational And Circular Dichroism Studies On N-Acetyl-L-Prolyl-D-Alanyl-Methylamide, S. Ramaprasad Jan 1990

Conformational And Circular Dichroism Studies On N-Acetyl-L-Prolyl-D-Alanyl-Methylamide, S. Ramaprasad

Journal of the Arkansas Academy of Science

The compact ordered conformations of the molecule N-Acteyl-L-Prolyl-D-Alanyl-Methylamide have been studied by semiempirical energy calculations in vacuum and circular dichroism (CD) in solution. The presence of ordered structure has been observed in hydrogen bond promoting solvents like trifluoroethanol by CD studies. In hydrogen bond breaking solvents, like trifluoroacetic acid (TFA), significant fraction of the ordered conformers probably assume extended conformation without intramolecular hydrogen bonds and perhaps are in equilibrium with the fraction of compact ordered structures. The trend observed in going from nonpolar to polar solvent is also compatible with the previous NMR studies in solution. The semiempirical energy calculations …