Ursan.[天]大熊星座；[天]小熊星座Urn.铀Uroglenopsis apiculatan.尖尾拟辐尾藻Uriaplasma urealyticum解脲脲原体Uromyces oblongisporusn.长椭圆单胞锈菌Urokinase thrombolysis尿激酶Uromyces kunigamiensisn.国头单胞锈菌Uronema simplicissimumn.简单尾丝藻urhidrosis crystallina[医] 结晶尿汗症uroporphyrin isomerase尿卟啉(同分)异构酶uric acid urolithiasis尿酸尿石病Urothelial cell atypia膀胱上皮细胞非典型性