[Early and mid-term results after 17 mm St Jude Regent mechanical valve replacement in 44 patients with small aortic root].

Objective: To analyze the changes in the cardiac function after St. Jude Regent mechanical valve replacement and assess the prosthesis-patient matching.

Methods: From October 2007 to March 2009, 44 patients received implantation of 17 mm St.

Simultaneous determination of 42 organic chemicals in bottled water by combining C18 extraction disk with GC-MS and LC/MS/MS technique.

A method for the determination of 42 hazard residues required by 'Japan Positive List System' in bottled water was described. Hazard compounds in bottled water were extracted with a solid phase extraction step using C18 disks. Determination was carried out by gas chromatography/mass spectrometry (GC/MS) and liquid chromatography-tandem mass spectrometry (LC/MS/MS).