An overview of the ciao multiparadigm language and program development environment and its design philosophy

We describe some of the novel aspects and motivations behind the design and implementation of the Ciao multiparadigm programming system. An important aspect of Ciao is that it provides the programmer with a large number of useful features from different programming paradigms and styles, and that the use of each of these features can be turned on and off at will for each program module. Thus, a given module may be using e.g. higher order functions and constraints, while another module may be using objects, predicates, and concurrency. Furthermore, the language is designed to be extensible in a simple and modular way. Another important aspect of Ciao is its programming environment, which provides a powerful preprocessor (with an associated assertion language) capable of statically finding non-trivial bugs, verifying that programs comply with specifications, and performing many types of program optimizations. Such optimizations produce code that is highly competitive with other dynamic languages or, when the highest levéis of optimization are used, even that of static languages, all while retaining the interactive development environment of a dynamic language. The environment also includes a powerful auto-documenter. The paper provides an informal overview of the language and program development environment. It aims at illustrating the design philosophy rather than at being exhaustive, which would be impossible in the format of a paper, pointing instead to the existing literature on the system

Enforcing Termination of Interprocedural Analysis

Interprocedural analysis by means of partial tabulation of summary functions may not terminate when the same procedure is analyzed for infinitely many abstract calling contexts or when the abstract domain has infinite strictly ascending chains. As a remedy, we present a novel local solver for general abstract equation systems, be they monotonic or not, and prove that this solver fails to terminate only when infinitely many variables are encountered. We clarify in which sense the computed results are sound. Moreover, we show that interprocedural analysis performed by this novel local solver, is guaranteed to terminate for all non-recursive programs --- irrespective of whether the complete lattice is infinite or has infinite strictly ascending or descending chains

Verification of Java Bytecode using Analysis and Transformation of Logic Programs

State of the art analyzers in the Logic Programming (LP) paradigm are nowadays mature and sophisticated. They allow inferring a wide variety of global properties including termination, bounds on resource consumption, etc. The aim of this work is to automatically transfer the power of such analysis tools for LP to the analysis and verification of Java bytecode (JVML). In order to achieve our goal, we rely on well-known techniques for meta-programming and program specialization. More precisely, we propose to partially evaluate a JVML interpreter implemented in LP together with (an LP representation of) a JVML program and then analyze the residual program. Interestingly, at least for the examples we have studied, our approach produces very simple LP representations of the original JVML programs. This can be seen as a decompilation from JVML to high-level LP source. By reasoning about such residual programs, we can automatically prove in the CiaoPP system some non-trivial properties of JVML programs such as termination, run-time error freeness and infer bounds on its resource consumption. We are not aware of any other system which is able to verify such advanced properties of Java bytecode

Unexpected solvent isotope effect on the triplet lifetime of methylene blue associated to cucurbit[7]uril

[EN] Methylene blue shows an isotope dependent triplet lifetime that is 50% longer in D2O compared with H2O as a result of electronic-to-vibrational relaxation. The effect is enhanced when the dye is bound to curcubit[7]uril due to a combination of restricted mobility and a unfavorable vibrational coupling.This work was supported by NSERC-Canada. M. G. B thanks the Spanish Ministry of Science and Innovation for a post-doctoral contract. E. A. Acknowledges Becas Chile and the University of Ottawa for postdoctoral fellowships. We also thank Michel Grenier for his help on the time resolved measurements.Alarcón, E.; González Béjar, M.; Montes Navajas, PM.; García Gómez, H.; Lissi, E.; Scaiano, JC. (2012). Unexpected solvent isotope effect on the triplet lifetime of methylene blue associated to cucurbit[7]uril. Photochemical & Photobiological Sciences. 11(2):269-273. doi:10.1039/c1pp05227fS269273112N. J. Turro , V.Ramamurthy and J. C.Scaiano, Modern molecular photochemistry of organic molecules, University Science Books, Sausalito, California, 2010Rekharsky, M. V., Ko, Y. H., Selvapalam, N., Kim, K., & Inoue, Y. (2007). Complexation Thermodynamics of Cucurbit[6]uril with Aliphatic Alcohols, Amines, and Diamines. Supramolecular Chemistry, 19(1-2), 39-46. doi:10.1080/10610270600915292Cohen, M. D., & Schmidt, G. M. J. (1964). 383. Topochemistry. Part I. A survey. Journal of the Chemical Society (Resumed), 1996. doi:10.1039/jr9640001996Cohen, M. D., Hirshberg, Y., & Schmidt, G. M. J. (1964). 389. Topochemistry. Part VII. The photoactivity of anils of salicylaldehydes in rigid solutions. Journal of the Chemical Society (Resumed), 2051. doi:10.1039/jr9640002051Cohen, M. D., Hirshberg, Y., & Schmidt, G. M. J. (1964). 390. Topochemistry. Part VIII. The effect of solvent, temperature, and light on the structure of anils of hydroxynaphthaldehydes. Journal of the Chemical Society (Resumed), 2060. doi:10.1039/jr9640002060Kim, J., Jung, I.-S., Kim, S.-Y., Lee, E., Kang, J.-K., Sakamoto, S., … Kim, K. (2000). New Cucurbituril Homologues:  Syntheses, Isolation, Characterization, and X-ray Crystal Structures of Cucurbit[n]uril (n= 5, 7, and 8). Journal of the American Chemical Society, 122(3), 540-541. doi:10.1021/ja993376pLee, J. W., Samal, S., Selvapalam, N., Kim, H.-J., & Kim, K. (2003). Cucurbituril Homologues and Derivatives:  New Opportunities in Supramolecular Chemistry. Accounts of Chemical Research, 36(8), 621-630. doi:10.1021/ar020254kHennig, A., Ghale, G., & Nau, W. M. (2007). Effects of cucurbit[7]uril on enzymatic activity. Chemical Communications, (16), 1614. doi:10.1039/b618703jKoner, A. L., & Nau, W. M. (2007). Cucurbituril Encapsulation of Fluorescent Dyes. Supramolecular Chemistry, 19(1-2), 55-66. doi:10.1080/10610270600910749Mohanty, J., Pal, H., Ray, A. K., Kumar, S., & Nau, W. M. (2007). Supramolecular Dye Laser with Cucurbit[7]uril in Water. ChemPhysChem, 8(1), 54-56. doi:10.1002/cphc.200600625Shaikh, M., Mohanty, J., Singh, P. K., Nau, W. M., & Pal, H. (2008). Complexation of acridine orange by cucurbit[7]uril and β-cyclodextrin: photophysical effects and pKashifts. Photochem. Photobiol. Sci., 7(4), 408-414. doi:10.1039/b715815gSueishi, Y., Asano, K., Yamaoka, M., & Yamamoto, S. (2008). Characterization of Water-Soluble Cucurbit[7]uril in Alcohol-Water Mixtures by High-Pressure Studies on the Inclusion Complexation with New Methylene Blue. Zeitschrift für Physikalische Chemie, 222(1), 153-161. doi:10.1524/zpch.2008.222.1.153Zhou, Y., Yu, H., Zhang, L., Sun, J., Wu, L., Lu, Q., & Wang, L. (2008). Host properties of cucurbit [7] uril: fluorescence enhancement of acridine orange. Journal of Inclusion Phenomena and Macrocyclic Chemistry, 61(3-4), 259-264. doi:10.1007/s10847-008-9414-8González-Béjar, M., Montes-Navajas, P., García, H., & Scaiano, J. C. (2009). Methylene Blue Encapsulation in Cucurbit[7]uril: Laser Flash Photolysis and Near-IR Luminescence Studies of the Interaction with Oxygen. Langmuir, 25(18), 10490-10494. doi:10.1021/la9011923Montes-Navajas, P., Corma, A., & Garcia, H. (2008). Complexation and Fluorescence of Tricyclic Basic Dyes Encapsulated in Cucurbiturils. ChemPhysChem, 9(5), 713-720. doi:10.1002/cphc.200700735Mohanty, J., & Nau, W. M. (2005). Ultrastable Rhodamine with Cucurbituril. Angewandte Chemie International Edition, 44(24), 3750-3754. doi:10.1002/anie.200500502Montes-Navajas, P., & Garcia, H. (2010). Cucurbituril Complexation Enhances Intersystem Crossing and Triplet Lifetime of 2,4,6-Triphenylpyrylium Ion. The Journal of Physical Chemistry C, 114(5), 2034-2038. doi:10.1021/jp9095166Van Houten, J., & Watts, R. J. (1975). Effect of ligand and solvent deuteration on the excited state properties of the tris(2,2’-bipyridyl)ruthenium(II) ion in aqueous solution. Evidence for electron transfer to solvent. Journal of the American Chemical Society, 97(13), 3843-3844. doi:10.1021/ja00846a062Schmidt, R., & Bodesheim, M. (1994). Time-Resolved Measurement of O2(1.SIGMA.+g) in Solution. Phosphorescence from an Upper Excited State. The Journal of Physical Chemistry, 98(11), 2874-2876. doi:10.1021/j100062a024Hurst, J. R., & Schuster, G. B. (1983). Nonradiative relaxation of singlet oxygen in solution. Journal of the American Chemical Society, 105(18), 5756-5760. doi:10.1021/ja00356a009Schmidt, R., & Brauer, H. D. (1987). Radiationless deactivation of singlet oxygen (1.DELTA.g) by solvent molecules. Journal of the American Chemical Society, 109(23), 6976-6981. doi:10.1021/ja00257a012Rodgers, M. A. J. (1983). TIME RESOLVED STUDIES OF 1.27 μm LUMINESCENCE FROM SINGLET OXYGEN GENERATED IN HOMOGENEOUS and MICROHETEROGENEOUS FLUIDS. Photochemistry and Photobiology, 37(1), 99-103. doi:10.1111/j.1751-1097.1983.tb04440.xRodgers, M. A. J., & Snowden, P. T. (1982). Lifetime of oxygen (O2(1.DELTA.g)) in liquid water as determined by time-resolved infrared luminescence measurements. Journal of the American Chemical Society, 104(20), 5541-5543. doi:10.1021/ja00384a070Ogilby, P. R., & Foote, C. S. (1983). Chemistry of singlet oxygen. 42. Effect of solvent, solvent isotopic substitution, and temperature on the lifetime of singlet molecular oxygen (1.DELTA.g). Journal of the American Chemical Society, 105(11), 3423-3430. doi:10.1021/ja00349a007Gardner, P. J., & Kasha, M. (1969). Electronic Consequences of Vibrational Deficiency in Polyatomic Molecules. The Journal of Chemical Physics, 50(4), 1543-1552. doi:10.1063/1.1671240Schweitzer, C., & Schmidt, R. (2003). Physical Mechanisms of Generation and Deactivation of Singlet Oxygen. Chemical Reviews, 103(5), 1685-1758. doi:10.1021/cr010371dS. L. Murov , I.Carmichael and G. L.Hug, Handbook of photochemistry, Mercel Decker Inc, New York, 1993Beeby, A., Parker, A. W., Simpson, M. S. C., & Phillips, D. (1992). The effect of solvent deuteration on the photophysics of sulphonated aluminium phthalocyanine. Journal of Photochemistry and Photobiology B: Biology, 16(1), 73-81. doi:10.1016/1011-1344(92)85154-mNau, W. M., & Mohanty, J. (2005). Taming fluorescent dyes with cucurbituril. International Journal of Photoenergy, 7(3), 133-141. doi:10.1155/s1110662x05000206Alarcón, E., Edwards, A. M., Aspee, A., Moran, F. E., Borsarelli, C. D., Lissi, E. A., … Scaiano, J. C. (2010). Photophysics and photochemistry of dyes bound to human serum albumin are determined by the dyelocalization. Photochem. Photobiol. Sci., 9(1), 93-102. doi:10.1039/b9pp00091gDavila, J., & Harriman, A. (1990). PHOTOREACTIONS OF MACROCYCLIC DYES BOUND TO HUMAN SERUM ALBUMIN. Photochemistry and Photobiology, 51(1), 9-19. doi:10.1111/j.1751-1097.1990.tb01678.xEngst, P., Kubát, P., & Jirsa, M. (1994). The influence of D2O on the photophysical properties of meso-tetra (4-sulphonatophenyl) porphine, Photosan III and tetrasulphonated aluminium and zinc phthalocyanines. Journal of Photochemistry and Photobiology A: Chemistry, 78(3), 215-219. doi:10.1016/1010-6030(93)03730-5Jensen, R. L., Arnbjerg, J., & Ogilby, P. R. (2010). Temperature Effects on the Solvent-Dependent Deactivation of Singlet Oxygen. Journal of the American Chemical Society, 132(23), 8098-8105. doi:10.1021/ja101753nLipert, R. J., & Colson, S. D. (1989). Deuterium isotope effects on S1 radiationless decay in phenol and on intermolecular vibrations in the phenol-water complex. The Journal of Physical Chemistry, 93(1), 135-139. doi:10.1021/j100338a030Tanielian, C., & Wolff, C. (1995). Determination of the Parameters Controlling Singlet Oxygen Production via Oxygen and Heavy-Atom Enhancement of Triplet Yields. The Journal of Physical Chemistry, 99(24), 9831-9837. doi:10.1021/j100024a02

Microparticles Harboring Sonic Hedgehog Morphogen Improve the Vasculogenesis Capacity of Endothelial Progenitor Cells Derived from Myocardial Infarction Patients.

Endothelial progenitor cells (EPC) play a role in endothelium integrity maintenance and regeneration. Decreased numbers of EPC or their impaired function correlates with an increase in cardiovascular events. Thus, EPC are important predictors of cardiovascular mortality and morbidity. Microparticles carrying Sonic hedgehog (Shh) morphogen (MPShhþ) trigger pro-angiogenic responses, both in endothelial cells and in ischaemic rodent models. Here, we propose that MPShhþ regulates EPC function, thus enhancing vasculogenesis, and correcting the defects in dysfunctional EPC obtained from acute myocardial infarction (AMI) patients

Aging enhances contraction to thromboxane A2 in aorta from female senescence mice

The time-course for aging-associated effects on vascular reactivity to U46619, a stable analogue of thromboxane A2 (TXA2), was studied in aorta from female senescence-accelerated mice-prone (SAMP8), a murine model of accelerated senescence. SAMP8 and senescence-accelerated mice-resistant (SAMR1) were divided into three groups: 3-, 6- and 10-month-old. Contractile curves to U46619 (10−9 to 10−6 M) were performed in aortic rings in the absence or in the presence of nitric oxide synthase (NOS) inhibitor NG-nitro-L-arginine methyl ester (L-NAME; 10−4 M) and/or cyclooxygenase (COX) inhibitor indomethacin (10−5 M). Protein and gene expression for COX-1 and COX-2 were determined by immunofluorescence and real-time PCR, respectively. Maximal contraction to U46619 was markedly higher in SAMP8 at all ages. In SAMR1, increases were seen at 10 months, while SAMP8 displays augmented contraction at 6 months, which was further increased at 10 months. L-NAME enhanced U46619 contractions in both 6-month-old groups, although the increase was higher on vessels from SAMR1 at this age. Indomethacin equally increased U46619 contractions in both 3-month-old groups, suggesting the production of vasodilator prostaglandin in young animals. In contrast, at 6 and 10 months indomethacin decreased U46619 contractions in both groups, indicating an aging-associated swap to a release of contractile prostanoids in aorta. In conclusion, aging enhances contractile responses to TXA2 in aorta from female mice by a mechanism involving a decrease of NO production and increased action of contractile prostanoids. This process occurs earlier in SAMP8 mice, establishing these mice as good model to study cardiovascular aging in a convenient and standard time-course

Automatic parallelization of irregular and pointer-based computations: perspectives from logic and constraint programming

Irregular computations pose some of the most interesting and challenging problems in automatic parallelization. Irregularity appears in certain kinds of numerical problems and is pervasive in symbolic applications. Such computations often use dynamic data structures which make heavy use of pointers. This complicates all the steps of a parallelizing compiler, from independence detection to task partitioning and placement. In the past decade there has been significant progress in the development of parallelizing compilers for logic programming and, more recently, constraint programming. The typical applications of these paradigms frequently involve irregular computations, which arguably makes the techniques used in these compilers potentially interesting. In this paper we introduce in a tutorial way some of the problems faced by parallelizing compilers for logic and constraint programs. These include the need for inter-procedural pointer aliasing analysis for independence detection and having to manage speculative and irregular computations through task granularity control and dynamic task allocation. We also provide pointers to some of the progress made in these áreas. In the associated talk we demónstrate representatives of several generations of these parallelizing compilers

Determinacy analysis for logic programs using mode and type information

We propose an analysis for detecting procedures and goals that are deterministic (i.e. that produce at most one solution), or predicates whose clause tests are mutually exclusive (which implies that at most one of their clauses will succeed) even if they are not deterministic (because they cali other predicates that can produce more than one solution). Applications of such determinacy information include detecting programming errors, performing certain high-level program transformations for improving search efñciency, optimizing low level code generation and parallel execution, and estimating tighter upper bounds on the computational costs of goals and data sizes, which can be used for program debugging, resource consumption and granularity control, etc. We have implemented the analysis and integrated it in the CiaoPP system, which also infers automatically the mode and type information that our analysis takes as input. Experiments performed on this implementation show that the analysis is fairly accurate and efncient

Bimetallic iron-copper oxide nanoparticles supported on nanometric diamond as efficient and stable sunlight-assisted Fenton photocatalyst

[EN] Bimetallic iron and copper oxide nanoparticles (NPs) supported on hydroxylated diamond (D3) exhibits an improved activity for the heterogeneous Fenton phenol degradation under natural or simulated sunlight irradiation with respect to analogous monometallic samples or than analogous FeCu NPs on graphite, activated carbon and P25 TiO2 semiconductor. FeCu/D3 catalyst exhibits good recyclability and stability especially working at pH 6. Overall, the high activity of the Fe20Cu80(0.2 wt%)/D3 catalyst is mainly due to the combination of the high activity of reduced copper species decomposing H2O2 to HO center dot radical, while Fe2+ allows the regeneration of these reduced copper species.S.N. thanks financial support by the Fundacion Ramon Areces (XVIII Concurso Nacional para la Adjudicacion de Ayudas a la Investigacion en Ciencias de la Vida y de la Materia, 2016), Ministerio de Ciencia, Innovacion y Universidades RTI2018-099482-A-I00 project and Generalitat Valenciana grupos de investigacion consolidables 2019 (ref: AICO/2019/214) project. H.G. thanks financial support by the Spanish Ministry of Science and Innovation (Severo Ochoa SEV2016 and RTI2018-890237-CO2-1) and Generalitat Valenciana (Prometeo 2017/083) is also gratefully acknowledged.Manickam-Periyaraman, P.; Espinosa, JC.; Ferrer Ribera, RB.; Subramanian, S.; Alvaro Rodríguez, MM.; García Gómez, H.; Navalón Oltra, S. (2020). Bimetallic iron-copper oxide nanoparticles supported on nanometric diamond as efficient and stable sunlight-assisted Fenton photocatalyst. Chemical Engineering Journal. 393:1-11. https://doi.org/10.1016/j.cej.2020.124770S111393Malato, S., Fernández-Ibáñez, P., Maldonado, M. I., Blanco, J., & Gernjak, W. (2009). Decontamination and disinfection of water by solar photocatalysis: Recent overview and trends. Catalysis Today, 147(1), 1-59. doi:10.1016/j.cattod.2009.06.018Pera-Titus, M., Garcı́a-Molina, V., Baños, M. A., Giménez, J., & Esplugas, S. (2004). Degradation of chlorophenols by means of advanced oxidation processes: a general review. Applied Catalysis B: Environmental, 47(4), 219-256. doi:10.1016/j.apcatb.2003.09.010Pignatello, J. J., Oliveros, E., & MacKay, A. (2006). Advanced Oxidation Processes for Organic Contaminant Destruction Based on the Fenton Reaction and Related Chemistry. Critical Reviews in Environmental Science and Technology, 36(1), 1-84. doi:10.1080/10643380500326564Rahim Pouran, S., Abdul Aziz, A. R., & Wan Daud, W. M. A. (2015). Review on the main advances in photo-Fenton oxidation system for recalcitrant wastewaters. Journal of Industrial and Engineering Chemistry, 21, 53-69. doi:10.1016/j.jiec.2014.05.005Cheng, M., Zeng, G., Huang, D., Lai, C., Xu, P., Zhang, C., & Liu, Y. (2016). Hydroxyl radicals based advanced oxidation processes (AOPs) for remediation of soils contaminated with organic compounds: A review. Chemical Engineering Journal, 284, 582-598. doi:10.1016/j.cej.2015.09.001Garrido-Ramírez, E. G., Theng, B. K. ., & Mora, M. L. (2010). Clays and oxide minerals as catalysts and nanocatalysts in Fenton-like reactions — A review. Applied Clay Science, 47(3-4), 182-192. doi:10.1016/j.clay.2009.11.044Klavarioti, M., Mantzavinos, D., & Kassinos, D. (2009). Removal of residual pharmaceuticals from aqueous systems by advanced oxidation processes. Environment International, 35(2), 402-417. doi:10.1016/j.envint.2008.07.009Bokare, A. D., & Choi, W. (2014). Review of iron-free Fenton-like systems for activating H2O2 in advanced oxidation processes. Journal of Hazardous Materials, 275, 121-135. doi:10.1016/j.jhazmat.2014.04.054Chiron, S. (2000). Pesticide chemical oxidation: state-of-the-art. Water Research, 34(2), 366-377. doi:10.1016/s0043-1354(99)00173-6Chong, M. N., Jin, B., Chow, C. W. K., & Saint, C. (2010). Recent developments in photocatalytic water treatment technology: A review. Water Research, 44(10), 2997-3027. doi:10.1016/j.watres.2010.02.039Herney-Ramirez, J., Vicente, M. A., & Madeira, L. M. (2010). Heterogeneous photo-Fenton oxidation with pillared clay-based catalysts for wastewater treatment: A review. Applied Catalysis B: Environmental, 98(1-2), 10-26. doi:10.1016/j.apcatb.2010.05.004Wang, C., Liu, H., & Sun, Z. (2012). Heterogeneous Photo-Fenton Reaction Catalyzed by Nanosized Iron Oxides for Water Treatment. International Journal of Photoenergy, 2012, 1-10. doi:10.1155/2012/801694Ramirez, J. H., Maldonado-Hódar, F. J., Pérez-Cadenas, A. F., Moreno-Castilla, C., Costa, C. A., & Madeira, L. M. (2007). Azo-dye Orange II degradation by heterogeneous Fenton-like reaction using carbon-Fe catalysts. Applied Catalysis B: Environmental, 75(3-4), 312-323. doi:10.1016/j.apcatb.2007.05.003Navalon, S., Sempere, D., Alvaro, M., & Garcia, H. (2013). Influence of Hydrogen Annealing on the Photocatalytic Activity of Diamond-Supported Gold Catalysts. ACS Applied Materials & Interfaces, 5(15), 7160-7169. doi:10.1021/am401489nEspinosa, J. C., Navalón, S., Álvaro, M., & García, H. (2015). Silver Nanoparticles Supported on Diamond Nanoparticles as a Highly Efficient Photocatalyst for the Fenton Reaction under Natural Sunlight Irradiation. ChemCatChem, 7(17), 2682-2688. doi:10.1002/cctc.201500458Espinosa, J. C., Navalón, S., Álvaro, M., & García, H. (2016). Copper nanoparticles supported on diamond nanoparticles as a cost-effective and efficient catalyst for natural sunlight assisted Fenton reaction. Catalysis Science & Technology, 6(19), 7077-7085. doi:10.1039/c6cy00572aEspinosa, J. C., Catalá, C., Navalón, S., Ferrer, B., Álvaro, M., & García, H. (2018). Iron oxide nanoparticles supported on diamond nanoparticles as efficient and stable catalyst for the visible light assisted Fenton reaction. Applied Catalysis B: Environmental, 226, 242-251. doi:10.1016/j.apcatb.2017.12.060Garrido-Ramírez, E. G., Marco, J. F., Escalona, N., & Ureta-Zañartu, M. S. (2016). Preparation and characterization of bimetallic Fe–Cu allophane nanoclays and their activity in the phenol oxidation by heterogeneous electro-Fenton reaction. Microporous and Mesoporous Materials, 225, 303-311. doi:10.1016/j.micromeso.2016.01.013Karthikeyan, S., Pachamuthu, M. P., Isaacs, M. A., Kumar, S., Lee, A. F., & Sekaran, G. (2016). Cu and Fe oxides dispersed on SBA-15: A Fenton type bimetallic catalyst for N,N -diethyl- p -phenyl diamine degradation. Applied Catalysis B: Environmental, 199, 323-330. doi:10.1016/j.apcatb.2016.06.040Martin, R., Navalon, S., Delgado, J. J., Calvino, J. J., Alvaro, M., & Garcia, H. (2011). Influence of the Preparation Procedure on the Catalytic Activity of Gold Supported on Diamond Nanoparticles for Phenol Peroxidation. Chemistry - A European Journal, 17(34), 9494-9502. doi:10.1002/chem.201100955Council Directive 98/83/EC of 3 November 1998 on the quality of water intended for human consumption.Dhakshinamoorthy, A., Navalon, S., Alvaro, M., & Garcia, H. (2012). Metal Nanoparticles as Heterogeneous Fenton Catalysts. ChemSusChem, 5(1), 46-64. doi:10.1002/cssc.201100517Burkitt, M. J., & Mason, R. P. (1991). Direct evidence for in vivo hydroxyl-radical generation in experimental iron overload: an ESR spin-trapping investigation. 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Nitrogen-doped graphene as metal free basic catalyst for coupling reactions

[EN] N-doped defective graphene [(N)G] obtained by pyrolysis at 900 degrees C of chitosan contains about 3.7% of residual N atoms, distributed as pyridinic, pyrrolic and graphitic N atoms. It has been found that (N)G acts as basic catalyst promoting two classical C-C bond forming nucleophilic additions in organic chemistry, such as the Michael and the Henry additions. Computational calculations at DFT level of models corresponding to the various N atoms leads to the conclusion that N atoms are more stable at the periphery of the graphene sheets and that H adsorption on these sites is a suitable descriptor to correlate with the catalytic activity of the various sites. According to these calculations the most active sites are pyridinic N atoms at zig-zag edges of the sheets. In addition, N as dopant changes the reactivity of the neigh. bour C atoms. Water was found a suitable solvent to achieve high conversions in both reactions. In this solvent the initial distribution of N atoms is affected due to the easy protonation of the N-py to N-pyH sites. As an effect, C edge sites adjacent at N-PyH with an appropriate reactivity towards the alpha-C-H bond breaking are formed. The present results show the general activity of N-doped graphene as base catalysts and illustrate the potential of carbocatalysis to promote reactions of general interest in organic synthesis. (C) 2019 Elsevier Inc. All rights reserved.This work was supported by UEFISCDI (PN-III-P4-ID-PCE-2016-0146. nr. 121/2017 and project number PN-III-P1-1.1-TE-2016-2191. nr. 89/2018). Financial support by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa and CTQ2015-69653-CO2-R1) and Generalitat Valenciana (Prometeo 2017-083) is gratefully acknowledged. A.P thanks the Spanish Ministry of Science and Innovation for a Ramon y Cajal research associate contract.Candu, N.; Man, I.; Andrada, S.; Cojocaru, B.; Coman, SM.; Bucur, C.; Primo Arnau, AM.... (2019). Nitrogen-doped graphene as metal free basic catalyst for coupling reactions. Journal of Catalysis. 376:238-247. https://doi.org/10.1016/j.jcat.2019.07.011S23824737