Benedict Terkula Iber^1,2,*, Nor Azman Kasan^1,*, Donald Torsabo^1,2, Jenifer Wese Omuwa²

Journal of Renewable Materials, Vol.10, No.4, pp. 1097-1123, 2022, DOI:10.32604/jrm.2022.018142

Abstract Chitin was first discovered by its name from the Greek word “chiton”, which means “mail coat”. It is indeed a polysaccharide made up of naturally occurring acetyl-D-glucosamine monomers. Hatchett was the first researcher who extracted chitin from the shells of mollusks (crabs and lobsters), prawns, and crayfish in 1799. Later in 1811, Henri Braconnot discovered chitin in the cell walls of mushrooms and called it “fungine”. Chitin and chitosan are abundant in the biosphere as essential components of many organisms’ exoskeletons and as by-products of the global seafood industry. The biopolymer must be deacetylated before chitosan can be produced. It… More >

ESSI KESKINEN¹ , YASUHARU TAKAKU² , V. BENNO MEYER-ROCHOW³, TAKAHIKO HARIYAMA⁴

BIOCELL, Vol.26, No.3, pp. 357-367, 2002, DOI:10.32604/biocell.2002.26.357

Abstract The aims of this paper have been (a) to characterize marginal ommatidia from different eye regions through a detailed description of their distinct ultrastructural features in three different size-classes of L. exotica, and (b) to compare microanatomical characteristics of the marginal ommatidia with those of ommatidia of the same eye, but located further centrally. On the basis of transverse as well as longitudinal sections we conclude that new ommatidia are added from a crescentic dorso-anterio-ventral edge of the eye and that maturing ommatidia go through a sequence in which originally the nuclei of cone -, pigment-, and retinula cells are… More >