All articles starting with U
6,146 articles
Ultrasound computed tomography
Ultrasound computed tomography, or ultrasound tomography, is an imaging method that reconstructs cross-sectional maps of tissue sound speed and attenuation, developed mainly for breast cancer screening.
Ultrasound elastography
Ultrasound elastography is an imaging technique that measures the stiffness of soft tissue noninvasively, most often to stage liver fibrosis without biopsy and to characterize breast and thyroid lesions.
Ultrasound localization microscopy
Ultrasound localization microscopy (ULM) is a super-resolution medical ultrasound technique that localizes individual microbubble contrast agents to map microvasculature and blood flow, overcoming the resolution-penetration trade-off at centimeter depths.
Ultrasound microvessel imaging
Ultrasound microvessel imaging (UMI) is a family of ultrasound techniques that visualize blood flow in small vessels beyond conventional Doppler, including superb microvascular imaging and ultrasound localization microscopy.
Ultrasound molecular imaging
Ultrasound molecular imaging (USMI) is an imaging technique that uses ligand-bearing gas microbubbles, 1–10 µm across, to visualize molecular markers on vascular endothelium noninvasively and in real time.
Ultrasound surgery
Ultrasound surgery, known as high-intensity focused ultrasound (HIFU) or MR-guided focused ultrasound, destroys targeted internal tissue with focused beams and no incision, routinely treating uterine fibroids and essential tremor.
Ultrasound thalamotomy
Ultrasound thalamotomy is a noninvasive neurosurgical procedure in which MRI-guided focused ultrasound heats and destroys part of the thalamus to relieve medication-refractory tremor, first FDA-approved in 2016.
Ultrasound World Tour
Ultrasound World Tour is Lorde's fourth concert tour (2025-2026), supporting her album Virgin; 59 arena shows across North America, Europe, Oceania, and the Americas with a minimalist staging, L-ISA sound, and five-star reviews.
Ultrasound-assisted extraction
Ultrasound-assisted extraction (UAE) is a solid–liquid extraction method that applies ultrasonic waves to a solvent to release target compounds from plants, foods, and soils, cutting extraction time from hours to minutes.
Ultrasound-assisted synthesis
Ultrasound-assisted synthesis is a chemistry method using ultrasonic irradiation to accelerate synthesis. Its effects come from the implosive collapse of bubbles, which gives shorter reaction times and higher yields.
Ultrasound-guided biopsy
Ultrasound-guided biopsy is a percutaneous procedure in which real-time sonography directs a needle into a suspected lesion to obtain cells or tissue for diagnosis, best suited to superficial targets.
Ultrasound-guided injection
Ultrasound-guided injection is a procedure delivering corticosteroids or anesthetics into joints, tendon sheaths, bursae, or nerves while ultrasound imaging shows the needle tip in real time, improving accuracy over blind landmark-guided injections.
Ultrasound-propelled nanowire motors
Ultrasound-propelled nanowire motors are metallic nanowires a few micrometers long that move through liquid under ultrasound without chemical fuel, introduced in 2012 by Thomas E. Mallouk's and Joseph Wang's groups.
Ultrasound-triggered drug release
Ultrasound-triggered drug release is a drug delivery strategy in which externally applied ultrasound causes carriers such as microbubbles, liposomes, and nanoparticles to release drugs at a chosen body site.
Ultrasound, High-Intensity Focused, Transrectal
Transrectal high-intensity focused ultrasound (transrectal HIFU) ablates prostate tissue via a rectal transducer, treating prostate cancer and BPH; devices include Ablatherm and Sonablate, FDA-cleared since 2015.
UltraSPARC T1
The UltraSPARC T1, code-named Niagara, is a 64-bit Sun Microsystems server processor announced in November 2005, with eight SPARC cores running 32 threads and used in the Sun Fire T1000 and T2000.
UltraSPARC T2
The UltraSPARC T2, codenamed Niagara 2, is a 64-bit SPARC system-on-a-chip introduced by Sun Microsystems in 2007, running 64 hardware threads on eight cores with integrated networking, cryptography, and PCI-Express I/O.
UltraTech Cement
UltraTech Cement is an Indian cement manufacturer controlled by the Aditya Birla group through Grasim Industries, which acquired Larsen & Toubro's cement business in 2004 and made it India's largest.
Ultratop
Ultratop: the non-profit organization producing Belgium's official record charts (Ultratop 50 singles, Ultratop albums), founded 1995 by the Belgian music industry (BRMA). Separate Flemish and Walloon charts combine sales, downloads (since 2006), streaming and airplay (since 2016/2017), compiled weekly via GfK and Radiomonitor.
Ultraviolence (album)
Ultraviolence, Lana Del Rey's second studio album (2014, Polydor/Interscope), produced by Dan Auerbach in Nashville; slow-tempo rock and blues, debuted at No. 1 in 12 countries with 182,000 US first-week sales.
Ultraviolence (song)
Ultraviolence is the 2014 title track of Lana Del Rey's album Ultraviolence, produced by Dan Auerbach. It narrates an abusive relationship, quotes the Crystals' 'He Hit Me (And It Felt Like a Kiss)' and became the album's most controversial song.
Ultraviolet
Ultraviolet radiation, or UV light, is electromagnetic radiation with wavelengths between 100 and 400 nanometers, shorter than visible light, mostly from the Sun and filtered by ozone.
Ultraviolet (film)
Ultraviolet (film) is a 2006 science fiction action film directed by Kurt Wimmer. It stars Milla Jovovich as Violet, a hemophage protecting a boy from a government campaign.
Ultraviolet catastrophe
The ultraviolet catastrophe, also called the Rayleigh–Jeans catastrophe, is classical physics' false prediction that black-body radiation has infinite energy at short wavelengths, named by Ehrenfest in 1911.
Ultraviolet communication
Ultraviolet communication (UVC) is a form of optical wireless communication that transmits data on solar-blind 200 to 280 nm ultraviolet light, scattering through the atmosphere so no direct line of sight is needed.
Ultraviolet curing
Ultraviolet curing, or UV curing, is a polymerization method that hardens photosensitive resins, adhesives, coatings, and inks within seconds of UV irradiation, used industrially since the late 1950s.
Ultraviolet disinfection
Ultraviolet disinfection is a water and wastewater treatment process that uses UV-C light near 254 nm to damage microbial DNA and inactivate pathogens, including chlorine-resistant Cryptosporidium, without adding chemicals or forming disinfection byproducts.
Ultraviolet Explorer
The Ultraviolet Explorer (UVEX) is a NASA space telescope selected in 2024 to survey the entire sky in ultraviolet light, with a planned launch in 2030 and a two-year prime mission.
Ultraviolet germicidal irradiation
Ultraviolet germicidal irradiation (UVGI, germicidal ultraviolet) uses UVC energy, mainly 253.7 nm from low-pressure mercury lamps, to kill airborne and surface viruses, bacteria, and fungi via duct or upper-room systems in hospitals and buildings.
Ultraviolet index
The ultraviolet index (UVI) is a scale, reported in weather forecasts, that measures the skin-damaging strength of solar ultraviolet radiation, from 1 (low) to 11 or more (extreme).