Preparation of photoactive nitrogen-doped rutile

An easy way of preparing highly N-doped rutile photocatalysts (N-TiO 2 /R) in tubular furnace in a constant ammonia (NH 3 ) flow at 800-1000 °C temperature range is presented. New materials were compared to TiO 2 samples prepared at the same temperatures in air atmosphere as well as to the starting material. Complete transformation of amorphous and anatase phases to rutile was confirmed by XRD method. Successful incorporation of relatively high amounts of nitrogen (up to 17% at.), in form of either TiO 2 (N), TiO x N y or TiN, on photocatalysts' surface and in their lattice was confirmed using XPS and XRD analysis. Also presence of Ti 3+ was revealed by EPR studies. In contrast to pristine TiO 2 , the UV-vis/DR absorption spectra of N-modified photocatalysts extended significantly into the visible light region. Whereas nitrogen concentration as well as visible light absorption were found to increase with increasing modification temperature, photocatalytic activity was, on the contrary decreasing. This may be due to the very high nitrogen concentration, obtained at higher modification temperature, as well as the presence of small amount of conductive TiN phase on the N-TiO 2 /1000 °C photocatalyst surface. The artificial solar light activity of new photocatalysts after thermal treatment in NH 3 increased in comparison to starting material, due to nitrogen modification and presence of Ti 3+ ions. Activity under UV(-vis) light, though, decreased after modification procedure, probably due to smaller surface areas of new photocatalysts and complete anatase to rutile transformation. © 2012 Elsevier B.V. All rights reserved

TiO2 modified by ammonia as a long lifetime photocatalyst for dyes decomposition

Ammonia-modified TiO2 (TiO2/N), prepared in a pressure reactor was used as the well- active and longlife photocatalyst for the azo dye (Reactive Red 198) decomposition. The effect of aeration and the different value of the pH of the reaction medium on the photocatalytic degradation of Reactive Red 198 in water has been investigated. It has been reported that the degradation is greatly influenced by the reaction pH and the faster decomposition of azo dye took place at pH 3.5. When the solution was acidic, a larger amount of azo dye on the positively charged surface of TiO2 photocatalysts was adsorbed. From the obtained results it can be seen that the effectiveness of the decolourisation of the solution was faster by using the nitrogen-modified TiO2

Influence of annealing and rinsing on magnetic and photocatalytic properties of TiO 2

Samples of TiO 2, calcined at 100 °C (type 1) and 200 °C (type 2), have been prepared without and with water rinsing. The crystallite sizes determined by XRD method were smaller than 15 nm for both types of samples. Magnetic resonance spectra of the obtained samples have been studied in 230-300 K temperature range. Before rinsing no magnetic spectra were observed but after rinsing the magnetic response appeared in form of a resonance line centered at g eff ∼ 2.54 with linewidth ΔH pp ∼ 460 G in type 1 samples and g eff ∼ 2.26 with linewidth ΔH pp ∼ 220 G in type 2 samples. The integrated intensity of the observed spectrum was two times greater in the type 1 sample. The resonance line could be attributed to the localized magnetic moments in the correlated spin system formed during rinsing. The rinsing resulted also in higher photocatalytic properties under UV-VIS irradiation. It is suggested that the number of oxygen vacancies increases after rinsing and as they are involved in the formation of low oxidation states of titanium ions, they could be responsible for the appearance of the observed magnetic properties. © 2011 Elsevier B.V. All rights reserved

Amifostine pretreatment for patients with advanced colorectal cancer receiving folfox chemotherapy

19663 Background: Oxaliplatin plays a key role in the treatment of advanced colorectal cancer (CRC) but is associated with dose- limiting peripheral neuropathy (PN) in &gt;20% of patients. We investigated the effects of amifostine, a cytoprotective agent, on the prevention of PN in patients receiving oxaliplatin in combination with 5-fluorouracil (5-FU) and leucovorin (LV) (FOLFOX) for the treatment of advanced (stage =III) CRC. Methods: In this ongoing prospective observational study, patients with stage =III CRC are assigned to receive FOLFOX alone (oxaliplatin 85 mg/m2, 5-FU 400 mg/m2 bolus, 5-FU 1.2 or 2.4 g/m2 continuous infusion over 46 h, LV 200 or 400 mg/m2) or FOLFOX plus 500 mg subcutaneous amifostine 30 minutes before chemotherapy. Some patients also receive bevacizumab and/or panitumumab. All patients receive Ca/Mg infusion (1 g each/100 mL normal saline) before and after oxaliplatin treatment. Incidence and degree of PN are assessed during biweekly patient interviews and graded using National Cancer Institute Common Toxicity Criteria Version 3. Results: Sixteen patients have enrolled to date (9 nonamifostine, 7 amifostine; mean age, 60.2 y [range, 33–81 y]; 81% men). Currently, data for 6 patients (3 per group) who have completed 12 cycles of therapy are available. Two of 3 patients in the nonamifostine group reported PN grade =2 during treatment; 1 of these patients required multiple treatment interruptions because of grade 3 PN. The third nonamifostine patient reported grade 1 PN on only 2 occasions during treatment but experienced grade 2 PN at 3-month follow-up. No patient in the amifostine group reported grade =2 PN during the treatment period. One amifostine patient required a reduction in oxaliplatin dose after 8 cycles because of neutropenia. At 3-month follow-up, 1 amifostine-treated patient reported grade 1 tingling in his hands and is currently receiving treatment with pregabalin. Conclusions: The use of amifostine for the prevention of oxaliplatin-induced PN is investigational. Patients with advanced CRC who received amifostine with FOLFOX chemotherapy had a decreased incidence and severity of PN compared with patients who did not receive amifostine. Updated data will be available at the time of presentation; study enrollment continues. No significant financial relationships to disclose. </jats:p