transport: Light-emitting diode

Evidence: 100 • authority: 72

A light-emitting diode (LED) is an electronic component that uses a semiconductor to emit light when current flows through it. Electrons in the semiconductor recombine with electron holes, thereby releasing energy in the form of photons. The color of the light (corresponding to the energy of the photons) is determined by the energy required for electrons to cross the band gap of the semiconductor. White light is obtained by using multiple semiconductors or a layer of light-emitting phosphor on the semiconductor device. Appearing as practical electronic components in 1962, the earliest LEDs emitted low-intensity infrared (IR) light. Infrared LEDs are used in remote-control circuits, such as…

Evidence: 53 • authority: 92

Mechanisms and clinical application of photobiomodulation in pain therapy: a mini review.. Chronic pain remains a major clinical challenge, creating a need for safe, non-pharmacological interventions. This narrative mini-review examines two light-based approaches that differ in their sites of action and treatment parameters: visual-light exposure and local red or near-infrared light-emitting diode photobiomodulation. Visual-light exposure acts through retinal and central neural circuits, including pathways involving the ventrolateral geniculate nucleus, dorsal raphe nucleus, periaqueductal gray, medial secondary visual cortex, and anterior cingulate cortex. Its effects are wavelength- and c…

Evidence: — • authority: 92

Postharvest preservation of fruits and vegetables by light-emitting diodes.. Postharvest losses of fruits and vegetables remain a major challenge because of rapid physiological deterioration, microbial spoilage, and quality degradation during storage and distribution. Light-based technologies, particularly light-emitting diodes (LEDs) and ultraviolet (UV) irradiation, have emerged as promising non-thermal and residue-free approaches for preserving postharvest quality through precise regulation of wavelength, intensity, and exposure duration. However, reported responses remain highly variable across species, cultivars, developmental stages, and treatment conditions, limiting the establishmen…