All articles starting with U

Urenco USA

Urenco USA is a gas centrifuge uranium enrichment plant in Eunice, New Mexico, the only commercial-scale enricher in the United States and supplier of about one third of US enrichment needs.

Urengoy gas field

The Urengoy gas field (Уренгойское месторождение) is a giant gas field in Western Siberia, Russia, discovered in 1966 with reserves of 10.9 trillion cubic meters.

Urengoy-Center Gas Pipeline

The Urengoy-Center Gas Pipeline (Газопровод Уренгой - Центр) is a Gazprom natural gas pipeline carrying gas from the Urengoy field to Tambov Oblast, commissioned in 1984.

Urengoy-Chelyabinsk Gas Pipeline

The Urengoy-Chelyabinsk gas pipeline, also called Urengoy–Surgut–Chelyabinsk, is a Russian natural gas pipeline carrying gas from the Urengoyskoye field in Siberia to Chelyabinsk, built from 1975 and operated by Gazprom.

Urengoy-Novopskov Gas Pipeline

The Urengoy-Novopskov Gas Pipeline (Russian: Газопровод Уренгой-Новопсков) is a 56-inch natural gas trunk pipeline from the Urengoy field in Siberia to Novopskov in Ukraine's Luhansk region, operating since 1982.

Urengoy-Petrovsk Gas Pipeline

The Urengoy-Petrovsk Gas Pipeline (Газопровод Уренгой-Петровск) is a Russian trunk gas pipeline from the Urengoy gas field in Siberia to Petrovsk, in service since 1982.

Urengoy-Pomary-Uzhgorod Gas Pipeline

The Urengoy-Pomary-Uzhgorod Gas Pipeline (Система газопроводов Уренгой — Помары — Ужгород), completed in 1983, carries natural gas from Siberia's Urengoy field across Russia and Ukraine to Uzhgorod.

Ureohydrolase

Ureohydrolases (EC 3.5.3.-) are metal-dependent hydrolase enzymes, including arginase (EC 3.5.3.1) and agmatinase (EC 3.5.3.11), that hydrolyze guanidino groups of arginine or agmatine to release urea, using a binuclear manganese active site.

Sep 17, 2026

Ureter

Ureter: muscular tube (Greek oureter) carrying urine from renal pelvis to bladder; about 25 cm, 3–4 mm wide, peristaltic, with anti-reflux intramural segment and UPJ, iliac, UVJ landmarks.

Oct 20, 2026

Ureteral fistula

Ureteral fistula, including ureterovaginal and ureteroarterial fistula, is an abnormal connection between the ureter and the vagina or a blood vessel, usually after pelvic surgery, stenting, or radiation, causing incontinence or hematuria.

Ureteral reimplantation

Ureteral reimplantation, also called ureteroneocystostomy, is a urologic operation that reconnects the ureter to the bladder to correct vesicoureteral reflux, achieving 95 to 99 percent correction in open surgery.

Ureterectomy

Ureterectomy is a urologic surgical procedure that removes part or all of a ureter, most often to treat upper urinary tract cancer while preserving the kidney when possible.

Ureterolithotomy

Ureterolithotomy is a urological operation that removes a ureteral stone intact through a longitudinal incision of the ureter, reserved for large or impacted stones when shock wave lithotripsy or ureteroscopy fail.

Ureterolysis

Ureterolysis is a urologic surgical procedure that frees the ureters from scar tissue caused by retroperitoneal fibrosis and repositions them, restoring urine drainage from kidney to bladder.

Ureteroneocystostomy

Ureteroneocystostomy is a surgical procedure that reimplants the ureter into the bladder, most often to stop vesicoureteral reflux, relieve distal ureteral obstruction, or restore drainage after kidney transplantation.

Ureteroplasty

Ureteroplasty is the surgical repair or reconstruction of the ureter, the tube carrying urine from kidney to bladder, ranging from endoscopic dilation to robot-assisted reconstruction with buccal mucosa grafts.

Ureterorenoscopy

Ureterorenoscopy (URS) is an endoscopic procedure in which a ureteroscope is passed through the urethra and bladder into the ureter to diagnose and treat stones.

Ureteroscopes

Ureteroscopes are thin endoscopes passed through the urethra into the ureters and kidneys for diagnosis and stone treatment. Semi-rigid and flexible (fibreoptic, digital chip-on-tip, single-use such as LithoVue) types, deflection up to 275 degrees.

Ureteroscopy

Ureteroscopy is a urologic endoscopic procedure in which a ureteroscope is passed through the urethra and bladder into the ureter and kidney to diagnose and treat stones, tumors, and strictures.

Ureterostomy

Ureterostomy is a urologic operation that brings one or both ureters to the skin surface, creating a stoma that drains urine past the bladder without using intestine.

Ureteroureterostomy

Ureteroureterostomy is a urologic reconstructive operation that joins two ureters end to end or end to side, restoring urine drainage past injury, stricture, or congenital obstruction, performed open, laparoscopically, or robot-assisted.

Urethane

Urethane, or ethyl carbamate (CAS 51-79-6), is a fermentation-formed process contaminant in bread, wine, beer, and stone-fruit spirits; IARC Group 2A carcinogen, historically a hypnotic and antileukaemic drug.

Sep 17, 2026

Urethra

The urethra is the thin-walled tube that carries urine from the bladder to the outside of the body, and in males, whose urethra is about 20 cm long, it also conveys semen.

Urethral abscess

Urethral abscess (periurethral abscess, ICD-10 N34.0) is a rare pus collection around the urethra, mostly in men with strictures or STIs; treated by drainage, antibiotics, and urinary diversion.

Urethral caruncle

Urethral caruncle, a benign polypoid growth at the urethral meatus, commonest in postmenopausal women; linked to low estrogen, treated first with vaginal estrogen, excised if symptomatic, 7% recurrence.

Urethral dilation

Urethral dilation is a urological procedure that widens a narrowed urethra (a stricture) using graduated instruments or a balloon, done under local anesthesia to relieve obstructive urinary symptoms.

Oct 20, 2026

Urethral discharge

Urethral discharge, also called urethral discharge syndrome, is abnormal urethral secretions, the hallmark of urethritis, usually from sexually transmitted Neisseria gonorrhoeae or Chlamydia trachomatis infection.

Urethral diverticulum

A urethral diverticulum is an outpouching of the urethra into the periurethral tissue, occurring almost entirely in women with an estimated prevalence of 1–6%.

Urethral fistula

Urethral fistula (ICD-11 GC04.0): abnormal passage between the urethra and adjacent organs or skin, caused by surgery, infection, trauma, or congenital factors; usually requires surgical repair.