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排序方式: 共有205条查询结果,搜索用时 15 毫秒
41.
Cristina Jimnez-Holgado Paola Calza Debora Fabbri Federica Dal Bello Claudio Medana Vasilios Sakkas 《Molecules (Basel, Switzerland)》2021,26(17)
This study investigated the direct and indirect photochemical degradation of citalopram (CIT), a selective serotonin reuptake inhibitor (SSRI), under natural and artificial solar radiation. Experiments were conducted in a variety of different operating conditions including Milli-Q (MQ) water and natural waters (lake water and municipal WWT effluent), as well as in the presence of natural water constituents (organic matter, nitrate and bicarbonate). Results showed that indirect photolysis can be an important degradation process in the aquatic environment since citalopram photo-transformation in the natural waters was accelerated in comparison to MQ water both under natural and simulated solar irradiation. In addition, to investigate the decontamination of water from citalopram, TiO2-mediated photocatalytic degradation was carried out and the attention was given to mineralization and toxicity evaluation together with the identification of by-products. The photocatalytic process gave rise to the formation of transformation products, and 11 of them were identified by HPLC-HRMS, whereas the complete mineralization was almost achieved after 5 h of irradiation. The assessment of toxicity of the treated solutions was performed by Microtox bioassay (Vibrio fischeri) and in silico tests showing that citalopram photo-transformation involved the formation of harmful compounds. 相似文献
42.
Lo Giudice A Re A Angelici D Calusi S Gelli N Giuntini L Massi M Pratesi G 《Analytical and bioanalytical chemistry》2012,404(1):277-281
Broad beam ionoluminescence (IL) microscopy is a promising technique for the non-destructive characterisation of rocks and stone objects. Luminescence imaging by means of broad ion beams has been sporadically used by other authors but, to our knowledge, its potential has not yet been fully investigated, neither in geological science nor in other fields. The in-air broad beam IL microscope was developed and installed at the INFN-LABEC external microbeam in Florence. Similar to the cathodoluminescence (CL) microscope, the apparatus exploits a CCD colour camera collecting images (few square millimetres wide, with ~10-μm spatial resolution) of the luminescence emitted by the sample hit by a defocused megaelectron volt (MeV) proton beam. The main differences with the well-established and widespread CL are the possibility of working in air (no sampling or conductive coatings required) and the possibility of combining the analysis with microbeam analysis, such as, for example, μ-IL and μ-PIXE (particle-induced X-ray emission). To show the potential of the technique, IL images of thin sections of lapis lazuli are compared with those obtained by means of an in-vacuum cold CL. An application to the study of stone artworks is also reported. This technique and apparatus will provide a valuable help for interdisciplinary applications, e.g. in geological sciences and in the cultural heritage field. 相似文献
43.
We have developed a fully adaptive optimization environment suitable to solve complex optimal control problems restricted by partial differential algebraic equations (PDAEs) and pointwise constraints on the control [1, 2]. This contribution is devoted to the inclusion of pointwise constraints on the state within the optimization environment. To this end we first give a brief introduction into the architecture of the environment and the inclusion of pointwise constraints on the state by Moreau-Yosida regularization. Then, we test the new tool by applying it to an optimal boundary control problem for the cooling of hot glass down to room temperature, modeled by radiative heat transfer and semi-transparent boundary conditions. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
44.
Treatment, removal and recovery of lead (3 mg/L) from battery industry wastewaters have been investigated utilising a chemical precipitation process with soluble starch xanthate (SX) at pH 5-6. A reactant ratio, i.e., SX/Pb(II) = 6 mol/mol, a reaction time of 15 min., the addition of 15 mg/L of a cationic polyelectrolyte and a final filtration gave residual lead concentrations in the liquid phase less than 0.2 mg/L, well below the maximum limit established by the EU Directive. Lead was extracted from the obtained sludge by oxidation with sodium hypochlorite or hydrogen peroxide solutions. The amounts of oxidant needed were quantified as 13.5 mol NaClO/mol Pb and one order of magnitude larger, for H2O2, the latter due to the competitive disproportion reaction of the oxidant. The metal extraction was quantitative using sodium hypochlorite; when hydrogen peroxide was used, the formation of insoluble PbSO4 (Anglesite) gave a 80% metal extraction. In both cases molar ratios between sulphate and lead ions in the extracted solutions were in the range 2.1-2.2, in agreement with the stoichiometries of the reactions. Lead can be quantitatively recovered from the extracted (NaClO) solutions, for reuse, after a chemical precipitation process with 1M NaOH at pH 9-9.5, in the form of hydrocerussite [Pb3(CO3)2(OH)2]. 相似文献
45.
Bontempo D Heredia KL Fish BA Maynard HD 《Journal of the American Chemical Society》2004,126(47):15372-15373
In this communication we report a strategy for the synthesis of semitelechelic polymers reactive to cysteines. An initiator modified with a pyridyl disulfide was prepared and used for the CuBr/2,2'-bipyridine-mediated atom transfer radical polymerization (ATRP) of 2-hydroxyethyl methacrylate. Polydispersity indices (M(w)/M(n)) of the polymers with different molecular weights were 1.25 or less. The pyridyl disulfide end group was preserved during the polymerization and allowed direct conjugation of the polymer to cysteine residues of bovine serum albumin. The described method provides a general way for the preparation of protein-polymer conjugates through a reversible disulfide bond without the need for postsynthesis modification of the polymers. 相似文献
46.
Debora?S.?F.?Gay Yoshitaka?Gushikem Celso?C.?Moro Tania?M.?H.?Costa Edilson?V.?BenvenuttiEmail author 《Journal of Sol-Gel Science and Technology》2005,34(2):189-195
1,4-phenylenediamine-1-propylsilica hybrid xerogels were obtained for two composition at different temperatures of gelation, from 5 up to 70C. The morphological effects produced by the different gelation temperatures were investigated by using N2 adsorption-desorption isotherms and scanning electron microscopy. The thermal stability of the organic groups and their distribution on the xerogel matrix, i.e. the fraction of the organic groups that were trapped in closed pores, formed during the xerogel synthesis, and the fraction of organic groups present on the surface, were obtained by using infrared thermal analysis. The higher porosity of the xerogels and the higher thermal stability of the organic groups were achieved for samples gelled at 25C. 相似文献
47.
Mariana Alarcón-Correa Debora Walker Tian Qiu Peer Fischer 《The European physical journal. Special topics》2016,225(11-12):2241-2254
This minireview discusses whether catalytically active macromolecules and abiotic nanocolloids, that are smaller than motile bacteria, can self-propel. Kinematic reversibility at low Reynolds number demands that self-propelling colloids must break symmetry. Methods that permit the synthesis and fabrication of Janus nanocolloids are therefore briefly surveyed, as well as means that permit the analysis of the nanocolloids’ motion. Finally, recent work is reviewed which shows that nanoagents are small enough to penetrate the complex inhomogeneous polymeric network of biological fluids and gels, which exhibit diverse rheological behaviors. 相似文献
48.
Sofia Trakhtenberg Ramya Kumar Jason Bianchini Savin Thor Debora M. Martino 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(12):1311-1315
Photocrosslinking of thymine‐based water‐soluble polymer films was investigated at varying preparation conditions. Adding salt or decreasing the pH of the solution from which the films were cast resulted in the decreased efficiency of photoimmobilization, while increasing the pH was found to increase the photoimmobilization efficiency. A mechanistic rationale for the observed effects is proposed. 相似文献
49.
50.
Back Cover: Amino Acid Oxidation: A Combined Study of Cysteine Oxo Forms by IRMPD Spectroscopy and Simulations (Chem. Eur. J. 48/2016) 下载免费PDF全文