Modification of the Interlayer Surface of Layered Copper(II) Hydroxide Acetate with Benzoate Groups: Submicrometer Fiber Generation

We report on the functionalization of layered copper(II) hydroxide acetate with benzoic acid. The grafting of benzoate groups is characterized by thermogravimetry/differential scanning calorimetry, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The submicrometer fiber generation of the grafted material is clearly demonstrated through scanning electron microscopy. Copyright 2001 Academic Press.

Structural and ultrastructural description of the venom gland of Loxosceles intermedia (brown spider)

The brown spider, genus Loxosceles, is becoming of great medical importance, with envenomation (Loxoscelism) occurring throughout the world. The biological activities of the brown spider venom usually include dermonecrotic lesions at the bite site accompanied by hemolytic and haemorrhagic effects and also by renal failure. The objective of the present study was to describe the histology of the venom gland of L. intermedia using glands from adult spiders which were investigated by light microscopy, using immunohistochemical and staining methods, by transmission electron microscopy, and by scanning electron microscopy. The organization of the venom gland of Loxosceles intermedia follows the general architecture of spiders' venom glands. Using light microscopy and transmission electron microscopy we observed that the venom glands of L. intermedia present two layers of striated muscle fibers, an external layer and an internal layer in touch with an extracellular matrix which is a basement membrane structure and a fibrillar collagen matrix separating the muscular region from epithelial cells of the venom gland. Muscle cells are multinucleated, with nuclei peripherally placed and their cytoplasm rich in sarcoplasmic reticulum, myofibrills and continuous Z lines. By using scanning electron microscopy we can detect muscular cells from external layer as branching cells. Epithelial cells have their cytosol extremely rich in rough endoplasmic reticulum, mitochondria collection, Golgi apparatus, interdigitating membranes and secretory vesicles that ultimately accumulate the venom, a complex protein mixture.