Characterization of the lowest singlet and triplet states of S-Flurbiprofen

[EN] The photophysical properties of S-flurbiprofen [S-2-fluoro-alpha-methyl-4-biphenylacetic acid], a nonsteroidal anti-inflammatory drug, have been examined using steady-state and time-resolved spectroscopic techniques. The energy of its first singlet excited state is 99 kcal mol(-1). The fluorescence quantum yields and lifetimes (at 300 nm) have been determined in acetonitrile, methanol, hexane and PBS; they are in the range 0.15 2.0.co;2Castell, J. V., Gómez-Lechón, M. J., Miranda, M. A., & Morera, I. M. (1992). Phototoxicity of non-steroidal anti-inflammatory drugs: in vitro testing of the photoproducts of Butibufen and Flurbiprofen. Journal of Photochemistry and Photobiology B: Biology, 13(1), 71-81. doi:10.1016/1011-1344(92)80041-sLewis, F. D., Bassani, D. M., Caldwell, R. A., & Unett, D. J. (1994). Singlet State Cis,Trans Photoisomerization and Intersystem Crossing of 1-Arylpropenes. Journal of the American Chemical Society, 116(23), 10477-10485. doi:10.1021/ja00102a014Wintgens, V., Johnston, L. J., & Scaiano, J. C. (1988). Use of a photoreversible fulgide as an actinometer in one- and two-laser experiments. Journal of the American Chemical Society, 110(2), 511-517. doi:10.1021/ja00210a034S. L. Murov , I.Carmichael and G. L.Hug, Handbook of Photochemistry, Marcel Dekker, Inc., New York, 2nd edn., 1993S. S. Adams , B. J.Armitage and J. S.Nicholson, Hydroxybiphenyl compounds, Ger. Offen., 1974, 54 pp., CODEN: GWXXBX DE 2329125 19740103 CAN 82:16565 AN 1975:16565Fasani, E., Barberis Negra, F. F., Mella, M., Monti, S., & Albini, A. (1999). Photoinduced C−F Bond Cleavage in Some Fluorinated 7-Amino-4-quinolone-3-carboxylic Acids. The Journal of Organic Chemistry, 64(15), 5388-5395. doi:10.1021/jo982456tAlbini, A., & Monti, S. (2003). Photophysics and photochemistry of fluoroquinolones. Chemical Society Reviews, 32(4), 238. doi:10.1039/b209220

Study of the influence of emission control strategies on the soot content and fuel dilution in engine oil

[EN] The engine oil contamination by both particulate matter (PM) and fuel is becoming an important problem since strategies to control pollutant emissions in internal combustion engines (ICE) significantly increase their presence in engine oil. As a consequence, the engine oil loses its tribological properties compromising engine lubrication and leading to potential problems in engine such as wear, corrosion, etc. For that reason, the study of the oil degradation and contamination due to these strategies have a special interest to the engine manufacturers and engine oil formulators. In this paper, the engine oil soot content and fuel dilution is analysed under real engine conditions. The study is addressed from two different but complementary points of views. First, on-line measurements at several engine operating conditions are performed in order to further understand how the soot generation correlates with the oil soot content and other derived problems on oil performance. Then, experimental data available after the experimental campaign is used to calibrate a numerical model, based on Computational Fluid Dynamics (CFD), that estimate the amount of soot particles settled in the engine oil. Results show that soot particles are more present in oil when operating high load-speed conditions and during the Diesel Particulate Filter (DPF) regeneration cycles. Regarding the fuel dilution, delayed post-injections are critical since they significantly increase the amount of fuel in the engine oil. Numerical results also show the relationships between the soot particles generated during combustion and the amount of soot in engine oil, giving an enhanced comprehension of soot-in-oil deposition mechanisms.A. Garcia-Barbera is partially supported through the Programa Nacional de Formation de Recursos Humanos de Investigacion of Spanish Ministerio de Ciencia e Innovation [grant number BES-2016-078073]. The authors also wish to thank Dr. José M. Pastor for his inestimable assistance in the CFD model implementation and data post-processing.Tormos, B.; Novella Rosa, R.; Gómez-Soriano, J.; García-Barberá, A.; Tsuji, N.; Uehara, I.; Alonso, M. (2019). Study of the influence of emission control strategies on the soot content and fuel dilution in engine oil. Tribology International. 136:285-298. https://doi.org/10.1016/j.triboint.2019.03.066285298136Lloyd, A. C., & Cackette, T. A. (2001). Diesel Engines: Environmental Impact and Control. Journal of the Air & Waste Management Association, 51(6), 809-847. doi:10.1080/10473289.2001.10464315Fiebig, M., Wiartalla, A., Holderbaum, B., & Kiesow, S. (2014). Particulate emissions from diesel engines: correlation between engine technology and emissions. Journal of Occupational Medicine and Toxicology, 9(1), 6. doi:10.1186/1745-6673-9-6C. Directive, 91/441/EEC of 26 June 1991 amending Directive 70/220, EEC on the approximation of the laws of the Member States relating to measures to be taken against air pollution by emissions from motor vehicles.E. Regulation, Regulation (EC) No 595/2009 of the European Parliament and of the Council of 18 June 2009 on type-approval of motor vehicles and engines with respect to emissions from heavy duty vehicles (Euro VI) and on access to vehicle repair and maintenance information and amending Regulation (EC) No 715/2007 and Directive 2007/46/EC and repealing Directives 80/1269/EEC, 2005/55/EC and 2005/78/EC, Off J Eur Communities - Legislation 188.Agarwal, D., Singh, S. K., & Agarwal, A. K. (2011). Effect of Exhaust Gas Recirculation (EGR) on performance, emissions, deposits and durability of a constant speed compression ignition engine. Applied Energy, 88(8), 2900-2907. doi:10.1016/j.apenergy.2011.01.066Divekar, P. S., Chen, X., Tjong, J., & Zheng, M. (2016). Energy efficiency impact of EGR on organizing clean combustion in diesel engines. Energy Conversion and Management, 112, 369-381. doi:10.1016/j.enconman.2016.01.042Lattimore, T., Wang, C., Xu, H., Wyszynski, M. L., & Shuai, S. (2016). Investigation of EGR Effect on Combustion and PM Emissions in a DISI Engine. Applied Energy, 161, 256-267. doi:10.1016/j.apenergy.2015.09.080Li, X., Xu, Z., Guan, C., & Huang, Z. (2014). Impact of exhaust gas recirculation (EGR) on soot reactivity from a diesel engine operating at high load. Applied Thermal Engineering, 68(1-2), 100-106. doi:10.1016/j.applthermaleng.2014.04.029Singh, S. K., Agarwal, A. K., & Sharma, M. (2006). Experimental investigations of heavy metal addition in lubricating oil and soot deposition in an EGR operated engine. Applied Thermal Engineering, 26(2-3), 259-266. doi:10.1016/j.applthermaleng.2005.05.004George, S., Balla, S., & Gautam, M. (2007). Effect of diesel soot contaminated oil on engine wear. Wear, 262(9-10), 1113-1122. doi:10.1016/j.wear.2006.11.002Fang, J., Meng, Z., Li, J., Pu, Y., Du, Y., Li, J., … G. Chase, G. (2017). The influence of ash on soot deposition and regeneration processes in diesel particular filter. Applied Thermal Engineering, 124, 633-640. doi:10.1016/j.applthermaleng.2017.06.076Behn, A., Feindt, M., Matz, G., Krause, S., & Gohl, M. (2015). Fuel Transport across the Piston Ring Pack: Measurement System Development and Experiments for Online Fuel Transport and Oil Dilution Measurements. SAE Technical Paper Series. doi:10.4271/2015-24-2535Aldajah, S., Ajayi, O. O., Fenske, G. R., & Goldblatt, I. L. (2007). Effect of exhaust gas recirculation (EGR) contamination of diesel engine oil on wear. Wear, 263(1-6), 93-98. doi:10.1016/j.wear.2006.12.055Dennis, A. J., Garner, C. P., & Taylor, D. H. C. (1999). The Effect of EGR on Diesel Engine Wear. SAE Technical Paper Series. doi:10.4271/1999-01-0839Heredia-Cancino, J. A., Ramezani, M., & Álvarez-Ramos, M. E. (2018). Effect of degradation on tribological performance of engine lubricants at elevated temperatures. Tribology International, 124, 230-237. doi:10.1016/j.triboint.2018.04.015Mc Geehan, J. A., Alexander, W., Ziemer, J. N., Roby, S. H., & Graham, J. P. (1999). The Pivotal Role of Crankcase Oil in Preventing Soot Wear and Extending Filter Life in Low Emission Diesel Engines. SAE Technical Paper Series. doi:10.4271/1999-01-1525Motamen Salehi, F., Morina, A., & Neville, A. (2017). The effect of soot and diesel contamination on wear and friction of engine oil pump. Tribology International, 115, 285-296. doi:10.1016/j.triboint.2017.05.041Lenk, J.-R., Meyer, L., & Provase, I. S. (2014). Oil Dilution Model for Combustion Engines - Detection of Fuel Accumulation and Evaporation. SAE Technical Paper Series. doi:10.4271/2014-36-0170Gautam, M., Chitoor, K., Durbha, M., & Summers, J. C. (1999). Effect of diesel soot contaminated oil on engine wear — investigation of novel oil formulations. Tribology International, 32(12), 687-699. doi:10.1016/s0301-679x(99)00081-xWattrus, M. (2013). Fuel Property Effects on Oil Dilution in Diesel Engines. SAE International Journal of Fuels and Lubricants, 6(3), 794-806. doi:10.4271/2013-01-2680Andreae, M., Fang, H., & Bhandary, K. (2007). Biodiesel and Fuel Dilution of Engine Oil. SAE Technical Paper Series. doi:10.4271/2007-01-4036Antusch, S., Dienwiebel, M., Nold, E., Albers, P., Spicher, U., & Scherge, M. (2010). On the tribochemical action of engine soot. Wear, 269(1-2), 1-12. doi:10.1016/j.wear.2010.02.028Sato, H., Tokuoka, N., Yamamoto, H., & Sasaki, M. (1999). Study on Wear Mechanism by Soot Contaminated in Engine Oil (First Report: Relation Between Characteristics of Used Oil and Wear). SAE Technical Paper Series. doi:10.4271/1999-01-3573Green, D. A., Lewis, R., & Dwyer-Joyce, R. S. (2006). Wear effects and mechanisms of soot-contaminated automotive lubricants. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 220(3), 159-169. doi:10.1243/13506501jet140Tang, Z., Feng, Z., Jin, P., Fu, X., & Chen, H. (2017). The soot handling ability requirements and how to solve soot related viscosity increases of heavy duty diesel engine oil. Industrial Lubrication and Tribology, 69(5), 683-689. doi:10.1108/ilt-02-2015-0024George, S., Balla, S., Gautam, V., & Gautam, M. (2007). Effect of diesel soot on lubricant oil viscosity. Tribology International, 40(5), 809-818. doi:10.1016/j.triboint.2006.08.002Ryason, P. R., Chan, I. Y., & Gilmore, J. T. (1990). Polishing wear by soot. Wear, 137(1), 15-24. doi:10.1016/0043-1648(90)90014-2Broatch, A., Olmeda, P., Margot, X., & Gomez-Soriano, J. (2019). Numerical simulations for evaluating the impact of advanced insulation coatings on H2 additivated gasoline lean combustion in a turbocharged spark-ignited engine. Applied Thermal Engineering, 148, 674-683. doi:10.1016/j.applthermaleng.2018.11.106Broatch, A., Novella, R., García-Tíscar, J., & Gomez-Soriano, J. (2019). On the shift of acoustic characteristics of compression-ignited engines when operating with gasoline partially premixed combustion. Applied Thermal Engineering, 146, 223-231. doi:10.1016/j.applthermaleng.2018.09.089Lapuerta, M., Armas, O., & Hernández, J. J. (1999). Diagnosis of DI Diesel combustion from in-cylinder pressure signal by estimation of mean thermodynamic properties of the gas. Applied Thermal Engineering, 19(5), 513-529. doi:10.1016/s1359-4311(98)00075-1Payri, F., Molina, S., Martín, J., & Armas, O. (2006). Influence of measurement errors and estimated parameters on combustion diagnosis. Applied Thermal Engineering, 26(2-3), 226-236. doi:10.1016/j.applthermaleng.2005.05.006Zhu, X., Zhong, C., & Zhe, J. (2017). Lubricating oil conditioning sensors for online machine health monitoring – A review. Tribology International, 109, 473-484. doi:10.1016/j.triboint.2017.01.015Bredin, A., Larcher, A. V., & Mullins, B. J. (2011). Thermogravimetric analysis of carbon black and engine soot—Towards a more robust oil analysis method. Tribology International, 44(12), 1642-1650. doi:10.1016/j.triboint.2011.06.002Broatch, A., Margot, X., Novella, R., & Gomez-Soriano, J. (2017). Impact of the injector design on the combustion noise of gasoline partially premixed combustion in a 2-stroke engine. Applied Thermal Engineering, 119, 530-540. doi:10.1016/j.applthermaleng.2017.03.081Broatch, A., Novella, R., García-Tíscar, J., & Gomez-Soriano, J. (2018). Potential of dual spray injectors for optimising the noise emission of gasoline partially premixed combustion in a 2-stroke HSDI CI engine. Applied Thermal Engineering, 134, 369-378. doi:10.1016/j.applthermaleng.2018.01.108Yakhot, V., & Orszag, S. A. (1986). Renormalization group analysis of turbulence. I. Basic theory. Journal of Scientific Computing, 1(1), 3-51. doi:10.1007/bf01061452Angelberger, C., Poinsot, T., & Delhay, B. (1997). Improving Near-Wall Combustion and Wall Heat Transfer Modeling in SI Engine Computations. SAE Technical Paper Series. doi:10.4271/972881Issa, R. . (1986). Solution of the implicitly discretised fluid flow equations by operator-splitting. Journal of Computational Physics, 62(1), 40-65. doi:10.1016/0021-9991(86)90099-9Colin, O., & Benkenida, A. (2004). The 3-Zones Extended Coherent Flame Model (Ecfm3z) for Computing Premixed/Diffusion Combustion. Oil & Gas Science and Technology, 59(6), 593-609. doi:10.2516/ogst:2004043K. Huh, A phenomenological model of diesel spray atomization, Proc. of the international conf. on multiphase flows' 91-tsukuba.Reitz, R. D., & Diwakar, R. (1987). Structure of High-Pressure Fuel Sprays. SAE Technical Paper Series. doi:10.4271/870598Habchi, C., Lafossas, F. A., Béard, P., & Broseta, D. (2004). Formulation of a One-Component Fuel Lumping Model to Assess the Effects of Fuel Thermodynamic Properties on Internal Combustion Engine Mixture Preparation and Combustion. SAE Technical Paper Series. doi:10.4271/2004-01-1996Karlsson, A., Magnusson, I., Balthasar, M., & Mauss, F. (1998). Simulation of Soot Formation Under Diesel Engine Conditions Using a Detailed Kinetic Soot Model. SAE Technical Paper Series. doi:10.4271/981022Hiroyasu, H., & Kadota, T. (1976). Models for Combustion and Formation of Nitric Oxide and Soot in Direct Injection Diesel Engines. SAE Technical Paper Series. doi:10.4271/760129Wiedenhoefer, J. F., & Reitz, R. D. (2003). Multidimensional Modeling of the Effects of Radiation and Soot Deposition in Heavy-duty Diesel Engines. SAE Technical Paper Series. doi:10.4271/2003-01-056

Increased Oxidative Damage Associated with Unfavorable Cytogenetic Subgroups in Chronic Lymphocytic Leukemia

Oxidative stress contributes to genomic instability in chronic lymphocytic leukemia (CLL), but its relationship with the acquisition of specific chromosomal abnormalities is unknown. We recruited 55 untreated CLL patients and assessed 8-oxo-2 -deoxyguanosine (8-oxo-dG), glutathione, and malondialdehyde (MDA) levels, and we compared them among the cytogenetic subgroups established using fluorescence in situ hybridization (FISH). Significant increases in 8-oxo-dG and/or MDA were observed in patients with unfavorable cytogenetic aberrations (17p and 11q deletions) compared to the 13q deletion group. TP53 deletion patients exhibited a diminished DNA repair efficiency. Finally, cases with normal FISH also showed enhanced 8-oxo-dG, which could result in adverse outcomes

The triplet excited state of the biocative compound thiabendazole. Characterization and suitability as reporter for cyclodextrin complexation

Fluorescence spectroscopy, laser flash photolysis (LPF), and density functional theory calculations have been performed to characterize the photobehavior of thiabendazole (1). Direct LFP of 1 results in the generation of a transient absorbing at λmax = 570 nm identified as the triplet excited state (31∗). The intersystem crossing quantum yield is 0.91, and the triplet energy is 288 kJ mol−1. The singlet–triplet energy gap is 84 kJ mol−1. The behavior of thiabendazole within CDs results in a marked enhancement of the triplet lifetime, this change is attributed to the mobility restrictions of included 1 imposed by the cyclodextrin cavities.Financial support from the MICINN (Grants: CTQ2009-11027/BQU, CTQ2010-19909 and pre-doctoral fellowship to P.B.) and the Generalitat Valenciana (Prometeo Program) is gratefully acknowledged.Bartovsky, P.; Domingo, LR.; Jornet Olivé, MD.; Miranda Alonso, MÁ.; Tormos Faus, RE. (2012). The triplet excited state of the biocative compound thiabendazole. Characterization and suitability as reporter for cyclodextrin complexation. Chemical Physics Letters. 525-526:166-170. https://doi.org/10.1016/j.cplett.2012.01.001S166170525-52

Expanding the perspective of polymeric selective contacts in photovoltaic devices using branched polyethylenimine

This work studies the use of polymeric layers of polyethylenimine (PEI) as an interface modification of electron-selective contacts. A clearly enhanced electrical transport with lower contact resistance and significant surface passivation (about 3 ms) can be achieved with PEI modification. As for other conjugated polyelectrolytes, protonated groups of the polymer with their respective counter anions from the solvent create an intense dipole. In this work, part of the amine groups in PEI are protonated by ethanol that behaves as a weak Brønsted acid during the process. A comprehensive characterization including high-resolution compositional analysis confirms the formation of a dipolar interlayer. The PEI modification is able to eliminate completely Fermi-level pinning at metal/semiconductor junctions and shifts the work function of the metallic electrode by more than 1 eV. Induced charge transport between the metal and the semiconductor allows the formation of an electron accumulation region. Consequently, electron-selective contacts are clearly improved with a significant reduction of the specific contact resistance (less than 100 mO·cm2). Proof-of-concept dopant-free solar cells on silicon were fabricated to demonstrate the beneficial effect of PEI dipolar interlayers. Full dopant-free solar cells with conversion efficiencies of about 14% could be fabricated on flat wafers. The PEI modification also improved the performance of classical high-efficiency heterojunction solar cells.This research has been supported by the Spanish government through Grants PID2019-109215RB-C41, PID2019109215RB-C43, PID2020-115719RB-C21, and PID2020116719RB-C41 and funded by MCIN/AEI/10.13039/ 501100011033. Besides this the authors would like to thank Prof. Jordi LLorca for his expertise and helpful discussions of XPS results, as well as Dr. Rodrigo Fernández-Pacheco of the Laboratorio de Microscopias Avanzadas (LMA-INA) of Zaragoza for the HRTEM images and EDS and EELS analysis, and Guillaume Sauthier from ICN2 for his contribution through UPS measurements and discussions.Peer ReviewedPostprint (published version

Xanthone-photosensitized detoxification of the veterinary anthelmintic fenbendazole

Fenbendazole (1) is a common veterinary anthelmintic, toxic to water living microorganisms. Fluorescence quantum yields of 1 were found to be 0.11 in acetonitrile, 0.068 in methanol, 0.034 in cyclohexane, and 0.013 in water. The singlet excited state energy was ca. 96 kcal mol(-1) in all solvents. The phosphorescence spectrum of 1 in ethanol at 77 K displayed a maximum at 450 nm, leading to a triplet energy of 75 kcal mol(-1). Experimental excited state energies agree well with the results of OFT calculations at the time-dependent B3LYP/6-311+G(d,p)//B3LYP/6-31G(d) level. Laser flash photolysis (LFP) of 1 at 266 nm led to transients absorbing in the 300-700 nm range, ascribed to radical cation 1(.+), which were also observed upon 355 nm LFP of xanthone (XA) in the presence of 1. Solar-simulated photolysis revealed XA-enhanced photodegradation of 1 and led to decreased toxicity, as shown by Daphnia magna assays. (c) 2013 Elsevier B.V. All rights reserved.Financial support from the MICINN (CTQ2010-19909) and the Generalitat Valenciana (Prometeo Program) is gratefully acknowledged.Jornet Olivé, MD.; Castillo López, MÁ.; Sabater Marco, C.; R. Domingo, L.; Tormos Faus, RE.; Miranda Alonso, MÁ. (2013). Xanthone-photosensitized detoxification of the veterinary anthelmintic fenbendazole. Journal of Photochemistry and Photobiology A: Chemistry. 264:34-40. https://doi.org/10.1016/j.jphotochem.2013.05.002S344026

Effects and Mechanisms of Cognitive, Aerobic Exercise, and Combined Training on Cognition, Health, and Brain Outcomes in Physically Inactive Older Adults : The Projecte Moviment Protocol

Altres ajuts: It has also been rewarded with three pre-doctoral fellowships ( FPU014/01460, FI-2016, and FI-2018).Introduction: Age-related health, brain, and cognitive impairment is a great challenge in current society. Cognitive training, aerobic exercise and their combination have been shown to benefit health, brain, cognition and psychological status in healthy older adults. Inconsistent results across studies may be related to several variables. We need to better identify cognitive changes, individual variables that may predict the effect of these interventions, and changes in structural and functional brain outcomes as well as physiological molecular correlates that may be mediating these effects. Projecte Moviment is a multi-domain randomized trial examining the effect of these interventions applied 5 days per week for 3 months compared to a passive control group. The aim of this paper is to describe the sample, procedures and planned analyses. Methods: One hundred and forty healthy physically inactive older adults will be randomly assigned to computerized cognitive training (CCT), aerobic exercise (AE), combined training (COMB), or a control group. The intervention consists of a 3 month home-based program 5 days per week in sessions of 45 min. Data from cognitive, physical, and psychological tests, cardiovascular risk factors, structural and functional brain scans, and blood samples will be obtained before and after the intervention. Results: Effects of the interventions on cognitive outcomes will be described in intention-to-treat and per protocol analyses. We will also analyze potential genetic, demographic, brain, and physiological molecular correlates that may predict the effects of intervention, as well as the association between cognitive effects and changes in these variables using the per protocol sample. Discussion: Projecte Moviment is a multi-domain intervention trial based on prior evidence that aims to understand the effects of CCT, AE, and COMB on cognitive and psychological outcomes compared to a passive control group, and to determine related biological correlates and predictors of the intervention effects. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT03123900

Effects and Mechanisms of Cognitive, Aerobic Exercise, and Combined Training on Cognition, Health, and Brain Outcomes in Physically Inactive Older Adults: The Projecte Moviment Protocol

Introduction: Age-related health, brain, and cognitive impairment is a great challenge in current society. Cognitive training, aerobic exercise and their combination have been shown to benefit health, brain, cognition and psychological status in healthy older adults. Inconsistent results across studies may be related to several variables. We need to better identify cognitive changes, individual variables that may predict the effect of these interventions, and changes in structural and functional brain outcomes as well as physiological molecular correlates that may be mediating these effects. Projecte Moviment is a multi-domain randomized trial examining the effect of these interventions applied 5 days per week for 3 months compared to a passive control group. The aim of this paper is to describe the sample, procedures and planned analyses. Methods: One hundred and forty healthy physically inactive older adults will be randomly assigned to computerized cognitive training (CCT), aerobic exercise (AE), combined training (COMB), or a control group. The intervention consists of a 3 month home-based program 5 days per week in sessions of 45 min. Data from cognitive, physical, and psychological tests, cardiovascular risk factors, structural and functional brain scans, and blood samples will be obtained before and after the intervention. Results: Effects of the interventions on cognitive outcomes will be described in intention-to-treat and per protocol analyses. We will also analyze potential genetic, demographic, brain, and physiological molecular correlates that may predict the effects of intervention, as well as the association between cognitive effects and changes in these variables using the per protocol sample. Discussion: Projecte Moviment is a multi-domain intervention trial based on prior evidence that aims to understand the effects of CCT, AE, and COMB on cognitive and psychological outcomes compared to a passive control group, and to determine related biological correlates and predictors of the intervention effects.Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT03123900

Photodegradation of carbendazim sensitized by aromatic ketones

Carbendazim (1) is a benzimidazole extensively used as post-harvest fungicide on fruits and vegetables. The aim of the present work is to study the photodegradation of I sensitized by aromatic ketones, with special attention to mechanistic aspects and to the possible detoxification associated with photochemical treatment. Laser flash photolysis (LPF) lambda(exc) = 355 nm of xanthone (XA) and anthraquinone (AQ) was performed in MeCN solutions, in the presence of 1. A new transient absorbing at lambda(max) 500 and 320 nm was obtained and assigned to the semioxidized radical cation 1(+center dot). An exergonic thermodynamics for electron transfer quenching was confirmed by means of the Rehm-Weller equation. The same species was observed by direct LFP of 1 at 266 nm in polar solvents. Conversely, when a deoxygenated solution of 1 was submitted to LFP in cyclohexane the transient spectrum presented a band with maximum at 380 nm; it was assigned to the triplet excited state ((3)1*) on the basis of energy transfer to oxygen and beta-carotene. The photodegradation of 1 was achieved using XA and AQ as electron acceptors in a solar-simulator, in aerated aqueous medium; the reaction was faster with XA. Formation of a new photoproduct was initially observed; its structure was assigned as carbendazim N-C5 dimer (2). A balance of the total organic carbon (TOC) after prolonged irradiation indicated that mineralization does not occur to a significant extent, pointing to oxidative fragmentation of 1 and 2 to give a variety of low molecular weight products. To check whether the observed photodegradation of 1 results in a decreased toxicity, biological assays were performed using an established model based on the inhibition of mobility of Daphnia magna. The results demonstrate that photodegradation leads to a diminished toxicity, indicating that the photoproducts are less toxic than the parent compound. (C) 2013 Elsevier B.V. All rights reserved.Financial support from the MICINN (Grant: CTQ2010-19909) and the Generalitat Valenciana (Prometeo Program) is gratefully acknowledged.Jornet Olivé, MD.; Castillo López, MÁ.; Sabater Marco, C.; Tormos Faus, RE.; Miranda Alonso, MÁ. (2013). Photodegradation of carbendazim sensitized by aromatic ketones. Journal of Photochemistry and Photobiology A: Chemistry. 256:36-41. https://doi.org/10.1016/j.jphotochem.2013.02.004S364125

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

Meeting abstrac