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Abstract Background Some patients have noted a foul odor during radiation therapy sessions, but the cause of the odor remains unknown. Since we suspected that this phenomenon is due to ozone generated by ionizing radiation, this experimental study measured ozone concentrations in the treatment room and in a coiled polyvinyl chloride (PVC) tube placed within the radiation field. Methods We measured ozone concentrations using an ultraviolet absorption method and an ozone monitor. A PVC tube (inner diameter 7 mm, outer diameter 10 mm) was used to mimic the environment of the nasal cavity. The tube (790 cm) was coiled and set between two 4-cm-thick (for X-rays) or 2-cm-thick (for electron beams) water-equivalent solid phantoms. The sampling tube of the ozone monitor was inserted into the PVC tube, and the joint was sealed to prevent environmental air contamination. To measure ozone concentrations in the atmosphere, the sampling tube supplied with the unit was used. A linac was used on a full-sized treatment field (40 cm × 40 cm at a source-to-axis distance of 100 cm). The effect of an electron beam on ozone concentrations was also evaluated with a full-sized treatment field (40 cm × 40 cm at a source-to-surface distance of 100 cm). Results Ozone levels in the treatment room were undetectable before the start of daily treatment but reached 0.008 parts per million (ppm) or more at 1 h after the start of treatment. Concentrations then remained nearly constant at 0.010–0.015 ppm throughout the day. The maximum ozone concentration in the PVC tube was only 0.006 ppm, even when it was irradiated at 2400 monitor units/min. Depending on the X-ray dose rate, the concentration increased to a maximum of 0.010 ppm with oxygen flowing into the other end of the tube at 1.5 L/min. Ozone concentrations in the PVC tube did not differ significantly between X-ray and electron-beam irradiation. Conclusions Only traces of ozone were found in the PVC tube that was used to mimic the nasal passages during radiation, these concentrations were too low for human perception. However, ozone concentrations did reach potentially detectable levels in the treatment room.

In the title compound, [Lu(C 7 H 7 ) 3 (C 4 H 8 O) 2 ] ( 1 ), the Lu ion is coordinated by three benzyl and two tetra-hydro-furan ligands. Two of the benzyl groups are bonded in a classical η 1 -fashion through the methyl-ene via the ipso -carbon atom of the benzyl ligand in addition to bonding through the methyl-ene C atom, resulting in a modified trigonal-bipyramidal coordination geometry about the Lu center.

The reaction of EuI 2 (THF) 2 with potassium hydro-tris-(3,5-diiso-propyl-pyrazol-yl)borate (K[HB(3,5- i Pr2 pz) 3 ] (= KTp i Pr2 , pz = pyrazol-yl) in a molar ratio of 1:1.5 resulted in extensive ligand fragmentation and formation of the europium(II) mono(scorpionate) complex bis-(3,5-diisopropyl-1 H -pyrazole)[hydro-tris-(3,5-diiso-propyl-pyrazol-yl)borato]iodido-europium(II), [Eu(C 27 H 46 BN 6 )I(C 9 H 16 N 2 ) 2 ] or (Tp i Pr2 )(3,5- i Pr2 pzH) 2 Eu II I, 1 , in high yield (78%). As a typical by-product, small amounts of the sterically crowded pyraza-bole derivative trans -4,8-bis-(3,5-diiso-propyl-pyrazol-1-yl)-1,3,5,7-tetra-iso-propyl-pyraza-bole, C 36 H 62 B 2 H 8 or trans -{(3,5- i Pr2 pz)HB(μ-3,5- i Pr2 pz)} 2 , 2 , were formed. Both title compounds have been structurally characterized through single-crystal X-ray diffraction. In 1 , two isopropyl groups are each disordered over two orientations with occupancy ratios of 0.574 (10):0.426 (10) and 0.719 (16):0.281 (16). In 2 , one isopropyl group is similarly disordered, occupancy ratio 0.649 (9):0.351 (9).

In the title compound, [Yb(C(24)H(40)BN(6))(2)]·C(7)H(8), the Yb atom is coordinated by two tris(3-tert-butyl-5-methyl-pyrazol-1-yl)hydridoborate [Tp(tBu,Me)] ligands. One ligand binds in the κ(3) mode, throuh three N atoms of the pyrazolyl rings, the other ligand coordinates through two N atoms of the pyrazolyl rings and the H atom attached to the central B via an agostic-type inter-action through the B-H group of the second Tp(tBu,Me) ligand, giving an overall distorted octa-hedral geometry. One of the tert-butyl groups is disordered over two sites, with occupancies of 0.65 and 0.35.