title: Urea measurement by X-ray microanalysis in 50 picoliter specimens.
mesh_terms: D000818:Animals; D011232:Chemical Precipitation; D002712:Chlorides / Q000652:urine; D004577:Electron Probe Microanalysis / Q000379:methods*; D006801:Humans; D007668:Kidney / Q000378:metabolism; D010784:Photomicrography; D011188:Potassium / Q000652:urine; D051381:Rats; D012964:Sodium / Q000652:urine; D013053:Spectrophotometry; D014508:Urea / Q000652:urine*; D014961:X-Ray Diffraction
chemical_list: D002712:Chlorides; D014508:Urea; D012964:Sodium; D011188:Potassium