Lasers with a semiconductor diode as the active medium. Diode lasers transform electric energy to light using the same principle as a light-emitting diode (LED), but with internal reflection capability, thus forming a resonator where a stimulated light can reflect back and forth, allowing only a certain wavelength to be emitted. The emission of a given device is determined by the active compound used (e.g., gallium arsenide crystals doped with aluminum or indium). Typical wavelengths are 810, 1,060 and 1,300 nm. (From UMDNS, 2005)
The development and use of techniques to study physical phenomena and construct structures in the nanoscale size range or smaller.
Equipment Failure Analysis
Emission of LIGHT when ELECTRONS return to the electronic ground state from an excited state and lose the energy as PHOTONS. It is sometimes called cool light in contrast to INCANDESCENCE. LUMINESCENT MEASUREMENTS take advantage of this type of light emitted from LUMINESCENT AGENTS.
Nanometer-sized tubes composed of various substances including carbon (CARBON NANOTUBES), boron nitride, or nickel vanadate.
Stable elementary particles having the smallest known negative charge, present in all elements; also called negatrons. Positively charged electrons are called positrons. The numbers, energies and arrangement of electrons around atomic nuclei determine the chemical identities of elements. Beams of electrons are called CATHODE RAYS.
Maternal Serum Screening Tests
Optics and Photonics
A specialized field of physics and engineering involved in studying the behavior and properties of light and the technology of analyzing, generating, transmitting, and manipulating ELECTROMAGNETIC RADIATION in the visible, infrared, and ultraviolet range.
Macrocyclic polyethers with the repeating unit of (-CH2-CH2-O)n where n is greater than 2 and some oxygens may be replaced by nitrogen, sulfur or phosphorus. These compounds are useful for coordinating CATIONS. The nomenclature uses a prefix to indicate the size of the ring and a suffix for the number of heteroatoms.
Encyclopedias as Topic
Sequence Analysis, DNA
High-Throughput Nucleotide Sequencing
Techniques of nucleotide sequence analysis that increase the range, complexity, sensitivity, and accuracy of results by greatly increasing the scale of operations and thus the number of nucleotides, and the number of copies of each nucleotide sequenced. The sequencing may be done by analysis of the synthesis or ligation products, hybridization to preexisting sequences, etc.
Intrinsically Disordered Proteins
Functional proteins that do not have unique, stable, folded, three-dimensional native structures or that possess non-ordered regions under physiological conditions. They are characterized by extraordinary structural flexibility and plasticity, which enable them to adopt different conformations in response to different stimuli or different interactions.
Myositis, Inclusion Body
Progressive myopathies characterized by the presence of inclusion bodies on muscle biopsy. Sporadic and hereditary forms have been described. The sporadic form is an acquired, adult-onset inflammatory vacuolar myopathy affecting proximal and distal muscles. Familial forms usually begin in childhood and lack inflammatory changes. Both forms feature intracytoplasmic and intranuclear inclusions in muscle tissue. (Adams et al., Principles of Neurology, 6th ed, pp1409-10)