All articles starting with a number or symbol

3C 286

3C 286, also known as J1331+3030 or B1328+307, is a compact steep-spectrum quasar at redshift 0.849, the Very Large Array's prime flux density calibrator for over half a century.

3C 345

3C 345 is a bright, variable blazar quasar in Hercules about 5.5 billion light-years away, a core-dominated superluminal radio source monitored optically since the 1960s.

3C 390.3

3C 390.3, also cataloged as B1845+797, is a nearby broad-line radio galaxy whose double-peaked emission lines come from an accretion disc around a supermassive black hole.

3C 454.3

3C 454.3, also cataloged as PKS 2251+158, is a flat-spectrum radio quasar, a type of blazar, in Pegasus at redshift 0.859 that repeatedly became the sky's brightest gamma-ray source.

3C 48

3C 48 is a radio-loud quasar, the 48th entry in the Third Cambridge Catalogue of radio sources, whose 1963 redshift of z = 0.37 helped solve the puzzle of the radio stars.

3C 58

3C 58 is a filled-center supernova remnant and pulsar wind nebula in Cassiopeia, long identified with the supernova of AD 1181, though its age is now contested.

Oct 20, 2026

3C syndrome, or Ritscher-Schinzel syndrome (cranio-cerebello-cardiac dysplasia), is a rare congenital malformation syndrome with craniofacial, cerebellar, and cardiac defects, caused by WASHC5, CCDC22, or VPS35L variants, inherited autosomal or X-linked recessively.

3Com

3Com was an American networking equipment company founded in 1979 by Robert Metcalfe, the co-inventor of Ethernet, to commercialize Ethernet hardware; HP acquired it in 2010.

3D audio effect

The 3D audio effect, also called positional audio, creates the illusion that a sound originates from a specific point in three-dimensional space, typically through headphones using head-related transfer functions.

3D Bioplotter

The 3D Bioplotter is an extrusion-based 3D bioprinter developed at the University of Freiburg in 2002 and commercialized by EnvisionTEC, often cited as the first commercial bioprinter.

3D bioprinting

3D bioprinting: additive manufacturing of living tissue using cell-laden bioinks via extrusion, inkjet, laser, and photopolymerization methods; key challenge is vascularization of thick constructs.

3D braided fabrics

3D braided fabrics are multi-layer textile preforms with yarns intersecting in all three spatial directions, used as composite reinforcements; unlike 2D braids they resist delamination via out-of-plane interlacement, made by row-and-column or rotary braiding.

3D cell culture

3D cell culture is a cell biology technique for growing cells in three-dimensional scaffolds, gels, or aggregates, producing tissue-like architecture and cell–cell contacts absent from flat monolayers.

3D co-culture

3D co-culture is a cell culture method that grows distinct cell types together within a three-dimensional scaffold, recreating tissue-like contacts, gradients, and phenotypes for drug screening.

3D computed tomography

3D computed tomography (3D CT) is an X-ray imaging method that reconstructs cross-sectional attenuation measurements into a volumetric dataset, rendered as 3D images for diagnosis and treatment planning.

3D computer graphics

3D computer graphics, also called three-dimensional computer graphics, are graphics in which scenes are described mathematically in 3D and rendered into 2D images, using models, materials, and algorithms like rasterization and ray tracing.

3D concrete printing

3D concrete printing is an additive manufacturing method in civil engineering that extrudes cement-based material layer by layer from a digital model, without formwork, to build houses, buildings, and bridges.

3D conformal radiation therapy

3D conformal radiation therapy (3D-CRT) is a radiotherapy technique that shapes multiple beams to match the tumor's shape, permitting higher tumor doses while limiting dose to organs at risk.

3D content generation methods

3D content generation methods create usable 3D assets, geometry plus texture, from a text prompt or single image, using SDS lifting, native 3D diffusion, or feed-forward models like LRM.

3D convolutional neural network

A 3D convolutional neural network (3D CNN) applies convolutional filters across multiple axes of a data volume, learning features from video and volumetric images such as CT or MRI scans.

3D deconvolution (microscopy)

3D deconvolution (microscopy) is an image-processing method that removes or reassigns out-of-focus blur from three-dimensional fluorescence microscopy stacks, improving contrast and signal-to-noise ratio, most often for widefield microscopes.

3D display

A 3D display, also called a three-dimensional display, is a device that lets viewers perceive depth, spanning eyeglasses-based stereoscopic, glasses-free autostereoscopic, volumetric, light field, and holographic technologies.

Oct 21, 2026

3D domain

3D domain (Pfam PF06725, InterPro IPR010611) is a short bacterial protein domain named for three conserved aspartates, part of the catalytic double psi beta barrel of MltA lytic transglycosylases involved in peptidoglycan turnover; distinct from 3D domain swapping.

3D echocardiography

3D echocardiography is an ultrasound method that acquires volumetric, moving images of the heart, giving left ventricular volumes and ejection fraction with accuracy similar to cardiac MRI.

3D electron diffraction

3D electron diffraction (3D ED), including the MicroED and automated diffraction tomography (ADT) techniques, is a crystallographic method that determines structures of nanocrystals too small for X-ray diffraction.

3D film

3D film, also called stereoscopic cinema, presents offset left- and right-eye images, separated by polarized, anaglyph, or shutter glasses. First commercial film The Power of Love (1922); 1950s and post-Avatar booms; crosstalk, brightness loss, and vergence-accommodation conflict are its main drawbacks.