Search results
Results from the WOW.Com Content Network
Fibrils (from Latin fibra [1]) are structural biological materials found in nearly all living organisms. Not to be confused with fibers or filaments , fibrils tend to have diameters ranging from 10 to 100 nanometers (whereas fibers are micro to milli-scale structures and filaments have diameters approximately 10–50 nanometers in size).
The collagen fibrils are made of a mixture of type I and type V collagens. These molecules are tilted by about 15 degrees to the fibril axis, and because of this, the axial periodicity of the fibrils is reduced to 65 nm (in tendons, the periodicity is 67 nm). The diameter of the fibrils is remarkably uniform and varies from species to species.
A myofibril (also known as a muscle fibril or sarcostyle) [1] is a basic rod-like organelle of a muscle cell. [2] Skeletal muscles are composed of long, tubular cells known as muscle fibers, and these cells contain many chains of myofibrils. [3] Each myofibril has a diameter of 1–2 micrometres. [3]
Amyloid fibrils are generally composed of 1–8 protofilaments (one protofilament also corresponding to a fibril is shown in the figure), each 2–7 nm in diameter, that interact laterally as flat ribbons that maintain the height of 2–7 nm (that of a single protofilament) and are up to 30 nm wide; more often protofilaments twist around each ...
A collagen molecule is about 300 nm long and 1–2 nm wide, and the diameter of the fibrils that are formed can range from 50–500 nm. In tendons, the fibrils then assemble further to form fascicles, which are about 10 mm in length with a diameter of 50–300 μm, and finally into a tendon fibre with a diameter of 100–500 μm. [13]
In another level of complexity, the hydroxyapatite crystals are mineral platelets that have a diameter of approximately 70 to 100 nm and thickness of 1 nm. They originally nucleate at the gaps between collagen fibrils. [12] Similarly, the hierarchy of abalone shell begins at the nanolevel, with an organic layer having a thickness of 20 to 30 nm.
The fibrils were found to be rather mono-dispersed mostly with a diameter of ca. 5 nm although occasionally thicker fibril bundles were present. [40] By combining ultrasonication with an "oxidation pretreatment", cellulose microfibrils with a lateral dimension below 1 nm has been observed by AFM.
[1] [2] These structures (known as crazes) typically appear as linear features and frequently precede brittle fracture. The fundamental difference between crazes and cracks is that crazes contain polymer fibrils (5-30 nm in diameter [ 3 ] ), constituting about 50% of their volume, [ 4 ] whereas cracks do not.