Photocatalytic degradation of metoprolol tartrate in suspensions of two TiO2-based photocatalysts with different surface area. Identification of intermediates and proposal of degradation pathways.

This study investigates the efficiency of the photocatalytic degradation of metoprolol tartrate (MET), a widely used β 1-blocker, in TiO 2 suspensions of Wackherr's " Oxyde de titane standard" and Degussa P25. The study encompasses transformation kinetics and efficiency, identification of intermediates and reaction pathways. In the investigated range of initial concentrations (0.01-0.1mM), the photocatalytic degradation of MET in the first stage of the reaction followed approximately a pseudo-first order kinetics. The TiO 2 Wackherr induced a significantly faster MET degradation compared to TiO 2 Degussa P25 when relatively high substrate concentrations were used. By examining the effect of ethanol as a scavenger of hydroxyl radicals (OH), it was shown that the reaction with OH played the main role in the photocatalytic degradation of MET. After 240min of irradiation the reaction intermediates were almost completely mineralized to CO 2 and H 2O, while the nitrogen was predominantly present as NH4+. Reaction intermediates were studied in detail and a number of them were identified using LC-MS/MS (ESI+), which allowed the proposal of a tentative pathway for the photocatalytic transformation of MET as a function of the TiO 2 specimen

'Preconditioning' with Low Dose Lipopolysaccharide Aggravates the Organ Injury/Dysfunction Caused by Hemorrhagic Shock in Rats

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedRS is supported by the Program Science without Borders, CAPES Foundation, Ministry of Education of Brazil, Brasilia/DF, Brazil; NSAP is, in part, supported by the Bart’s and The London Charity (753/1722). The research leading to these results has received funding from the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007-2013) under REA grant agreement no 608765, from the William Harvey Research Foundation and University of Turin (Ricerca Locale ex-60%). This work contributes to the Organ Protection research theme of the Barts Centre for Trauma Sciences, supported by the Barts and The London Charity (Award 753/1722

Characterisation of surface oxygen groups on different carbon materials by the Boehm method and temperature-programmed desorption

The surface characteristics of different carbon materials: activated carbon, carbon felt, glassy carbon and a porous carbon monolith were investigated. The specific surface area was examined by the BET method with N(2) adsorption, the amount and the type of surface oxygen groups by Boehm titration as well as by temperature-programmed desorption (TPD). By comparing the results obtained using BET analysis with those of TPD and the Boehm method, it was found that the number of surface groups was not proportional to the specific surface area. The total amount of oxygen groups, obtained by TPD, is higher than the amount obtained by Boehms method for porous samples. The inconsistencies between these results originate from the fact that the Boehm method is limited to the determination of acidic and basic groups, whereas TPD provides information on the total number of all surface oxygen groups. In addition, the presence of porosity could reduce the solvent-accessible surface in the Boehm method. The TPD profiles of CO evolution showed the presence of a low temperature maximum, below 650 K, which originates from CO(2) reduction on the carbon material surface

Antitumor activity of Lamiaceae plants frequently used in Serbian folk medicine and cuisine.

Recently, cancer research has focused on searching for new and more effective antitumor agents of natural origin that can activate multiple defence mechanisms and selectively damage transformed cells. The goal of this research was to assess different antitumor mechanisms of ethanolic extracts of 18 Lamiaceae species traditionally used in Serbian folk medicine and cuisine, as well as their genotoxic potential towards HCT-116 (colorectal cancer) cells. The viability of treated HCT-116 cells was assessed by MTT assay; the production of reactive oxygen species (ROS) by treated HCT- 116 cells was determined using NBT assay, while their production of nitric oxide (NO) was evaluated using Griess assay. The genotoxic activity of the extracts on HCT-116 cells was tested in Comet assay, using etoposide as a positive control. The results indicated that lavender, basil, and rosemary inhibited the proliferation of these cells, significantly lowering their viability. Moreover, lavender and thyme extracts displayed a significant increase in ROS production, whereas ground- ivy, hyssop, lemon balm, peppermint, basil, rosemary, sage, and winter savory have significantly lowered their production. The results of the Griess assay suggested that lavender, motherwort, peppermint, basil, rosemary, sage, winter savory, ironwort, and thyme have significantly increased the production of NO. Furthermore, Comet assay results pointed out that motherwort, peppermint, basil, oregano, marjoram, winter savory, ironwort, wild thyme, thyme, and mountain germander possess genotoxic potential towards HCT-116 cells, while only basil had genotoxic activity statistically similar to etoposide. The obtained results are in accordance with our previous findings, which indicated that these extracts have antigenotoxic and genoprotective activities towards normal cells. Finally, it can be concluded that these traditionally valued plants might act as potent antitumor agents by modulating the proliferation and production of ROS and NO by cancer cells, as well as by expressing significant genotoxic properties towards cancer cells

Mass spectrometry analysis of polychlorinated biphenyls: chemical ionization and selected ion chemical ionization using methane as a reagent gas

In the present paper a quadrupole ion trap mass spectrometer, coupled with a gas chromatograph, was used to compare the electron impact ionization (EI) and chemical ionization (Cl) technique, in terms of their selectivity in polychlorinated biphenyls (PCBs) quantitative analysis. The experiments were carried out with a modified Varian SATURN III quadrupole ion-storage mass spectrometer equipped with Varian waveform generator, coupled with a gas chromatograph with DB-5 capillary column. The disadvantage of using EI in the analysis of PCBs congeners is the extensive fragmentation of the molecular ion. The main fragmentation pattern recorded in the EI mass spectra of PCBs was the loss of a chlorine atom from the molecular ion. Therefore the fragment-ion signal overlapped with the molecular-ion cluster of lower mass congener. The fragmentation reactions of PCBs are suppressed if methane is used as a reagent gas for chemical ionization, but fragment ions are also present in the spectrum as an obstruction for quantitative analysis. The most selective method for PCBs quantitative analysis appears to be Cl with mass-selected C2H5+ ions from methane, which results in a mass spectrum with a negligible amount of fragment ions

The micromorphological, histochemical and confocal analysis of satureja subspicata Bartl. ex vis. glandular trichomes

Micromorphology, histochemical and confocal analyses of the trichomes of Satureja subspicata (Bartl. ex Vis.) were carried out using light microscopy, confocal laser scanning electron microscopy (CLSM), and scanning electron microscopy. Non-glandular unbranched and two types of glandular trichomes - peltate and capitate - are described. The results of histochemical tests showed a positive reaction to phenolics, tannins, lipids, acid lipids, pectins and polysaccharides in both types of glandular trichomes. A strong red autofluorescence of the lipophilic and hydrophilic secreted material in glandular trichomes was observed with CLSM.</jats:p

Electrospray mass spectrometric studies of a potential antitumor drug and its analogous platinum(II) and platinum(IV) complexes with the ethylenediamine-N,N '-di-3-propanoato ligand and its dibutyl ester

The electrospray mass spectrometric (ESI-MS) behavior of the complexes trans-dichloro(ethylenediamine-N, N'-di-3-propionato) platinum(IV), trans-dibromo(ethylenediamine-N, N'-di-3-propionato) platinum( IV), dichloro (ethylenediamine-N,N'-di-3-propionic acid) platinum(II), tetrachloro(O,O'-di-n-butyl-ethylenediamine-N,N'-di-3-propanoate) platinum(IV), chlorotribromo(O,O'-di-n-butylethylenediamine-N,N'-di-3-propanoate) platinum(IV), and dichloro(O,O'-di-n-butyl-ethylenediamine-N,N'-di-3-propanoate) platinum( II), with the formulae trans-[PtCl(2) (eddp)] (1), trans-[PtBr(2)(eddp)] (2), [PtCl(2)(H(2)eddp)] (3), [PtCl(4)(Bu(2)eddp)] (4), [PtBr(3)Cl(Bu(2)eddp)] (5), and [PtCl(2)(Bu(2)eddp)]center dot H(2)O (6), is reported. The deprotonated molecular ions or halide adducts are usually observed. ESI-MS data demonstrate the usefulness of the method for efficient characterization of metal complexes in solution

Production of activated carbon derived from waste hemp (Cannabis sativa) fibers and its performance in pesticide adsorption

The main objective of this work was to find optimal production parameters for the preparation of activated hemp fibers (ACh) with good adsorption properties toward pesticides. In order to examine the role of manufacturing parameters on ACh surface characteristics, activation process of carbonized hemp fibers was investigated by temperature programmed reaction and evolved gaseous products of activation were monitored by mass spectrometry. ACh samples were characterized by BET surface area, scanning electron microscopy and temperature-programmed desorption. KOH activation induces the reduction of oxygen groups existing on the carbonized hemp fiber surface and the formation of the more stable, predominantly anhydride groups, while porosity development correlates with both H-2 and CO, evolved during the activation, and increases with carbonization and activation temperature. Finally, the highest efficiency in pesticides removal was achieved by carbonization of waste hemp fibers and activation at 900 degrees C with KOH/carbonized material ratio of 2/1. High efficiency in pesticides removal indicates that activated hemp fibers could be successfully used as a sorbent in water purification. (C) 2015 Elsevier Inc. All rights reserved