In such a system, the excited dye chromophore is reduced by different tetraorganylborate anions. Upon irradiation at 488 nm, reductive carbonboron bond cleavage occurs, producing reactive radicals, which start the chain reaction. The efficiency of bond-breaking processes was found to be dependent on the nature of both the acceptors and the donors. The experimental results show that the photoinitiating ability of the

tested photoredox pairs were controlled by both the driving force of the electron-transfer process between the electron donor and BAY 73-4506 the electron acceptor and the reactivity of the free radical that resulted from the secondary reactions occurring after the photoinduced electron-transfer Vorinostat inhibitor process. Using the nanosecond flash photolysis method, we studied the spectral and kinetic characteristics of the triplet state of cyanine dye and determined the rate constants of the triplet quenching by phenyltrialkylborate salts. The results obtained show that the tetramethylammonium phenyl-tri-n-butylborate (TB7) has a faster electron-transfer rate than the tetramethylammonium n-butyltriphenylborate (TB2) salt, which bore only one

butyl group attached to the boron. The relative initiator efficiency of the triphenylbutylborate salts, as compared to the corresponding phenyltrialkylborate salts with a common chromophore, was determined. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 3535-3544, 2012″
“The relationship between target volume and adverse radiation effects (AREs) at low prescription doses requires elucidation. The development of AREs in three series of patients treated in the Gamma Knife is analysed in relation to prescription dose and target volume.

There were three groups. In group 1, there were of 275 patients with meningiomas; in group 2, 132 patients with vestibular schwannomas; and in group 3, 107 patients with arteriovenous malformations (AVMs). The minimum follow-up

for each group was more than 24 months. All patients were followed up at six monthly intervals. The selleck compound patients with tumours received a prescription dose of 12 Gy, which was varied to protect normal structures but not in relation to tumour volume per se. The desired AVM prescription dose was 25 Gy, but this was also reduced to protect normal structures and to keep the total dose within certain pre-defined limits. All AREs refer to intra-parenchymal increased perilesional T2 signal on MR irrespective of clinical correlation.

There was no relationship between tumour volume and the development of ARE in the tumour groups. There was a highly significant relationship between target volume and the development of ARE for the AVMs with their much higher dose.