Validation of energy expenditure and macronutrient oxidation measured by two new whole-room indirect calorimeters.

Objective: The aim of this study was to validate two new whole-room indirfect calorimeters according to Room Indirect Calorimetry Operating and Reporting Standards (RICORS 1.0).

Methods: For technical validation, 16 propane combustion tests were performed to determine accuracy and precision of energy expenditure (EE) and ventilation rates of oxygen (VO ), carbon dioxide (VCO ), and respiratory exchange ratio (VCO /VO ).

Validation of whole room indirect calorimeters: refinement of current methodologies.

Whole room indirect calorimeter (WRIC) validation techniques consist of propane combustion (PC) or infusion of mixed carbon dioxide (CO) and nitrogen (N) by a precision blender (PB). To determine the best method, PC of 6, 10, 22-h and PB infusions of 6, 10, and 14-h, were conducted. The 14-h infusion consisted of two metabolic settings.

Extremely narrow SiON angles in siloxy-substituted nitrogen-containing rings: a computational investigation.

Quantum chemical calculations have been performed for a number of siloxy derivatives of pyrrolidine and piperidine in an attempt to gauge the effect of the saturated ring on the SiON angle. Most derivatives of pyrrolidine had SiON angles comparable to those previously observed for substituted N,N-dimethylhydroxylamines. However, piperidine derivatives were predicted to have particularly narrow SiON angles.

Highly asymmetric coordination of trimethylsilyl groups to tetrazole and triazole rings: an experimental and computational study in gaseous and crystalline phases.

1-Trimethylsilyltetrazole, 1, has been synthesised from chlorotrimethylsilane and tetrazole in the presence of triethylamine as an auxiliary base. The structure of this compound has been determined in the crystalline phase by X-ray diffraction of a crystal grown in situ. The gas-phase structures of 1 and 1-trimethylsilyl-1,2,4-triazole, 2, have been determined by gas-phase electron diffraction (GED).

Three-membered ring or open chain molecule - (F3C)F2SiONMe2 a model for the alpha-effect in silicon chemistry.

(F3C)F2SiONMe2 was prepared from LiONMe2 and F3CSiF3. It was characterized by gas IR and multinuclear solution NMR spectroscopy and by mass spectrometry. Its structure was elucidated by single crystal X-ray crystallography and by gas electron diffraction.

(Dimethylaminomethyl)trifluorosilane, Me2NCH2SiF3--a model for the alpha-effect in aminomethylsilanes.

F3SiCH2NMe2 was prepared as a model for the investigation of the nature of the alpha-effect in alpha-aminosilanes, by fluorination of Cl3SiCH2NMe2 with SbF3. Under less mild conditions Si--C bond cleavage was also observed, leading to the double adduct F4Si(Me2NCH2SiF3)2, which was characterised by a crystal structure analysis showing that the central SiF4 unit is connected to Me2NCH2SiF3 via SiN dative bonds and FSi contacts. F3SiCH2NMe2 was characterised by multinuclear NMR spectroscopy (1H, 13C, 15N, 19F and 29Si), gas-phase IR spectroscopy and mass spectrometry.