Nails are one of the important accessory structures of the skin. They are hard, protective structures that cover the dorsal surface of the distal phalanges of fingers and toes. Nails are composed of specialized keratinized cells and serve various functions, including protection, sensation, and manual dexterity.
The main components of a nail include the following.
Nail Plate: The nail plate is the visible portion of the nail that extends beyond the fingertips or toes. It is a hard, translucent...

In wood construction, fasteners are essential for securing components together, with the connection strength largely dependent on the direct bearing between members. Various types of fasteners are employed, each suited to specific applications and structural requirements.
Nails are the most common fasteners, consisting of sharp-pointed metal pins that are driven into wood using a hammer or a mechanical nail gun. They come in a variety of diameters, heads, and lengths. Nailing techniques include...

The intermediate filaments are an essential component of the cytoskeleton. Presently six types of intermediate filament have been identified. Type I and II are acidic and basic keratin proteins. Type III is of mesodermal origin and comprises four proteins: vimentin, desmin, glial fibrillary acidic protein (GFAP), and peripherin. Vimentin is commonly found in mesenchymal cells, desmin in muscle cells, GFAP in astrocytes, while peripherin is found in peripheral nervous system neurons (PNS). Type...

Lumber is derived from logs which are harvested, debarked, and processed into long pieces with a rectangular cross-section. The transformation of logs into lumber involves multiple steps, beginning with an automated saw that slices the log into slabs. These slabs are then transported via a conveyor belt to smaller saws, where they are cut into square-edged pieces of specific widths.
Initially, the surfaces of these lumber pieces are rough, and their dimensions may vary slightly from one end to...