Degradation of azoxystrobin, methoxyfenozide, and propyzamide by ultrasound treatment.

Ultrasound as a green and efficient process gains special attention in wastewater treatment. The ultrasound-assisted degradation of azoxystrobin, methoxyfenozide, and propyzamide as widely used pesticides for vine treatment was investigated. A wide range of ultrasonic power (40 to 140 W) and a single frequency (20 kHz) were applied.

Photodegradation of Myrigalone A, an Allelochemical from Myrica gale: Photoproducts and Effect of Terpenes.

This study investigated the environmental fate of myrigalone A, a light absorbing natural herbicide found on leaves and fruits of Myrica gale. Myrigalone A was irradiated in water and as a dry solid deposit to simulate reactions on leaves, alone and in the presence of the terpenes generated by Myrica gale. The phototransformation was fast ( t = 35 min in water).

Aqueous chlorination of sulfamethazine and sulfamethoxypyridazine: Kinetics and transformation products identification.

Sulfonamides (SNs) are synthetic antimicrobial agents. These substances are continually introduced into the environment, and they may spread and maintain bacterial resistance in the different compartments. The chlorination of 2 SNs, namely, sulfamethazine (SMT) and sulfamethoxypyridazine (SMP), was investigated to study their reactivity with chlorine at typical concentrations for water treatment conditions.

UV and IR Photochemistries of Malonaldehyde Trapped in Cryogenic Matrices.

UV and IR photochemistries of malonaldehyde, the simplest molecule exhibiting an intramolecular proton exchange, have been studied in four cryogenic matrices at 4.3 K, N, Ne, Ar, and Xe. Samples have been irradiated using a UV and IR OPO type tunable laser, and with a broad band UV mercury lamp.

Photodegradation of novel oral anticoagulants under sunlight irradiation in aqueous matrices.

Kinetics of photodegradation of novel oral anticoagulants dabigatran, rivaroxaban, and apixaban were studied under simulated solar light irradiation in purified, mineral, and river waters. Dabigatran and rivaroxaban underwent direct photolysis with polychromatic quantum yields of 2.2 × 10 and 4.

Oxidation of danofloxacin by free chlorine-kinetic study, structural identification of by-products by LC-MS/MS and potential toxicity of by-products using in silico test.

Unlabelled: In this study, we aimed to investigate the kinetics and the mechanism of reaction of the fluoroquinolone antibacterial danofloxacin (DANO) by free available chlorine (FAC) during water chlorination process. Kinetic study was thus performed at pH 7.2, 20 °C in the presence of an excess of total chlorine.

Far infrared spectra of solid state L-serine, L-threonine, L-cysteine, and L-methionine in different protonation states.

In this study, experimental far infrared measurements of L-serine, L-threonine, L-cysteine, and L-methionine are presented showing the spectra for the 1.0-13.0 pH range.

Photolysis of natural β-triketonic herbicides in water.

The fate of four natural β-triketones (leptospermone, isoleptospermone, grandiflorone and flavesone, pKa = 4.0-4.5) in aqueous solution, in the dark and upon simulated solar light irradiation was investigated.

Water extracts from winery by-products as tobacco defense inducers.

Water extracts from winery by-products exhibited significant plant defense inducer properties. Experiments were conducted on three marc extracts containing various amounts of polyphenols and anthocyanins. Infiltration of red, white and seed grape marc extracts into tobacco leaves induced hypersensitive reaction-like lesions with cell death evidenced by Evans Blue staining.

Genotoxicity of sulcotrione pesticide and photoproducts on Allium cepa root meristem.

Contamination by toxic agents in the environment has become matters of concern to agricultural countries. Sulcotrione, a triketone herbicide used to control dicotyledonous weeds in maize culture is rapidly photolyzed on plant foliage and generate two main photoproducts the xanthene-1,9-dione-3,4-dihydro-6-methylsulfonyl and 2-chloro-4-mesylbenzoic acid (CMBA). The aim of this study was to analyze the potential toxicity of the herbicide and the irradiated herbicide cocktail.

Transparent organosilica photocatalysts activated by visible light: photophysical and oxidative properties at the gas-solid interface.

The photophysical properties of several photosensitizers (PSs) included or grafted in silica monoliths were compared to their properties in solution. The effects of the solid support on their steady-state and transient absorption spectra, on their quantum yields of singlet oxygen ((1)O2) production, and on their ability to photoinduce the oxidation of dimethylsulfide (DMS) were investigated. Two cyanoanthracene derivatives (9,14-dicyanobenzo[b]triphenylene, DBTP, and 9,10-dicyanoanthracene, DCA), as well as three phenothiazine dyes (methylene blue, MB(+), new methylene blue, NMB(+), methylene violet, MV), were encapsulated in silica, analyzed and compared to two reference PSs (perinaphthenone, PN and rose bengal, RB).

Perinaphthenone phototransformation in a model of leaf epicuticular waxes.

Perinaphthenone (1H-phenalen-1-one, PN) is a reference photosensitizer producing singlet oxygen with a quantum yield close to one in a large variety of solvents. It is also the basic structure of a class of phototoxic phytoalexins. In this work, the PN photoreactivity was studied for the first time in a paraffinic wax, used as model of leaf epicuticular waxes.

Comparison of the photophysical properties of three phenothiazine derivatives: transient detection and singlet oxygen production.

New methylene blue (NMB+) and methylene violet (MV) are known for their photosensitizing properties for singlet oxygen ((1)O2) generation upon visible-light irradiation, and various examples of their use in the photodynamic inactivation of microorganisms and for photomedicinal purposes have been reported. However, their photophysical properties have never been extensively and systematically analyzed and compared. In the current work, we studied their absorption and fluorescence behavior relative to their parent compound, methylene blue (MB+), detected the transient species generated upon excitation of the photosensitizers and determined their quantum yields of singlet oxygen production.

Assessing the dual activity of a chalcone-phthalocyanine conjugate: design, synthesis, and antivascular and photodynamic properties.

Photodynamic therapy (PDT) and vascular-disrupting agents (VDA) each have their advantages in the treatment of solid tumors, but also present drawbacks. In PDT, hypoxia at the center of the tumor limits conversion of molecular oxygen into singlet oxygen, while VDAs are deficient at affecting the rim of the tumor. A phthalocyanine-chalcone conjugate combining the VDA properties of chalcones with the PDT properties of phthalocyanines was designed to address these deficiencies.

New insights into pesticide photoprotection.

Photolysis may be a significant route of pesticide dissipation on crops, leading to an increase of pesticide use. Spraying strong absorbing compounds (photoprotector) along with pesticide is an attractive strategy to prevent the photodegradation phenomenon. The aim of this study is to get a better understanding of the parameters governing the photoprotection efficiency.

Comparative studies in series of cytochrome c oxidase models.

This study compares the behavior as cytochrome c oxidase (CcO) functional and structural models of a series of reported and unreported ligands that provide either a binding site for copper without a built-in proximal base, or both a flexible binding site for copper and a built-in proximal base, or a fixed binding site for copper with a built-in proximal base. The comparisons of the models show that the relative position of the two metal sites is not only a crucial parameter in the control of the catalytic behavior but also essential in mimicking other features of the enzyme such as CO exchange between the ferrous heme a(3) and the cuprous Cu(B) center.

Probing the hydrogen bonding structure in the Rieske protein.

The use of the far-infrared spectral range presents a novel approach for analysis of the hydrogen bonding in proteins. Here it is presented for the analysis of Fe--S vibrations (500-200 cm(-1)) and of the intra- and intermolecular hydrogen bonding signature (300-50 cm(-1)) in the Rieske protein from Thermus thermophilus as a function of temperature and pH. Three pH values were adequately chosen in order to study all the possible protonation states of the coordinating histidines.

New insights into the photodynamics of acetylacetone: isomerization and fragmentation in low-temperature matrixes.

UV and IR photoreactivities of acetylacetone isolated at 4.3 K in four matrixes (N(2), Ne, Ar, Xe), pure and doped with O(2) are investigated, using either tunable UV and IR optical parametric oscillators, or a broad band mercury lamp. Samples are probed by UV and FTIR spectroscopies: electronic and vibrational transitions are assigned and irradiation kinetics are analyzed.

Educating for leadership: a programme designed to build a responsive health care culture.

Aim: To describe a leadership programme that progressively builds nurses capacity from the commencement of their employment to assist with the development of 'others'. Such an approach ultimately contributes to the creation of a team responsive to changing health care needs.

Background: The literature supports the relationship between positive leadership attributes, good nursing care and patient outcomes.

Far infrared spectra of solid state aliphatic amino acids in different protonation states.

Far infrared spectra of zwitterionic, cationic, and anionic forms of aliphatic amino acids in solid state have been studied experimentally. Measurements were done on glycine, L-alanine, L-valine, L-leucine, and L-isoleucine powder samples and film samples obtained from dried solutions prepared at pH ranging from 1 to 13. Solid state density functional theory calculations were also performed, and detailed potential energy distributions were obtained from normal mode results.

UV and IR photoisomerization of acetylacetone trapped in a nitrogen matrix.

UV- and IR-induced photoisomerization of acetylacetone trapped in a nitrogen matrix at 4.3 K have been carried out using a tunable optical parametric oscillator type laser, or a mercury vapor lamp, coupled with Fourier Transform IR and UV spectroscopies. After deposition, the main form present in the cryogenic matrix is that chelated (enol).

Experimental and theoretical UV characterizations of acetylacetone and its isomers.

Cryogenic matrix isolation experiments have allowed the measurement of the UV absorption spectra of the high-energy non-chelated isomers of acetylacetone, these isomers being produced by UV irradiation of the stable chelated form. Their identification has been done by coupling selective UV-induced isomerization, infrared spectroscopy, and harmonic vibrational frequency calculations using density functional theory. The relative energies of the chelated and non-chelated forms of acetylacetone in the S0 state have been obtained using density functional theory and coupled-cluster methods.

Matrix isolation Fourier transform infrared study of photodecomposition of formimidic acid.

The UV isomerization of formamide (HCONH2) trapped in xenon, nitrogen, argon, and neon cryogenic matrices has been monitored by Fourier transform infrared (FT-IR) spectroscopy. Formamide monomer is the only species present in the matrices after deposition; when UV-selective irradiation was carried out at 240 nm, the n --> pi transition allowed us to observe the formation of several isomers of formimidic acid [H(OH)C=NH]. On these latter species, we carried out selective IR irradiation of their OH stretching mode and compared the experimental and theoretical (B3LYP/6-311+G(2d,2p)) sets of bands.