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161.
Andreas Mautner Xiaohua Qin Harald Wutzel Samuel C. Ligon Barbara Kapeller Doris Moser Guenter Russmueller Juergen Stampfl Robert Liska 《Journal of polymer science. Part A, Polymer chemistry》2013,51(1):203-212
Monomers for radical photopolymerization based on vinyl esters (VEs) have recently been identified as suitable alternatives to (meth)acrylates on account of their low irritancy and cytotoxicity. The drawback of most VEs with abstractable hydrogens is their relatively low reactivity compared with (meth)acrylates. Within this article, we proved by photo‐differential scanning calorimetry measurements and real‐time Fourier transform infrared spectroscopy that the thiol‐ene concept is able to improve the photoreactivity of these VEs to a large extent to a level between those of acrylates and methacrylates. Other VEs have now a reactivity of at least the level of similar acrylates. Mechanical properties as determined by Dynamic Mechanical Analysis and Charpy impact tests showed significant toughening of these materials. Furthermore, we were able to confirm low toxicity of all components by osteoblast cell culture experiments. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
162.
163.
Barbara M. Cellamare Paola Fini Angela Agostiano Salvatore Sortino Pinalysa Cosma 《Photochemistry and photobiology》2013,89(2):432-441
Photodynamic therapy (PDT) is a way of treating malignant tumors and hyperproliferative diseases. It is based on the use of photosensitizer, herein the chlorophyll a (chl a), and a light of an appropriate wavelength. The interaction of the photosensitizer (PS) with the light produces reactive oxygen species (ROS), powerful oxidizing agents, which cause critical damage to the tissue. To solubilize chl a in aqueous solution and to obtain it as monomer, we have used cyclodextrins, carriers which are able to interact with the pigment and form the inclusion complex. The aim of this study is to examine which types of ROS are formed by Chl a/cyclodextrin complexes in phosphate buffered solution and cell culture medium, using specific molecules, called primary acceptors, which react selectively with the reactive species. In fact the changes of the absorption and the emission spectra of these molecules after the illumination of the PS provide information on the specific ROS formation. The 1O2 formation has been tested using chemical methods based on the use of Uric Acid (UA), 9,10‐diphenilanthracene (DPA) and Singlet oxygen sensor green (SOSG) and by direct detection of Singlet Oxygen (1O2) luminescence decay at 1270 nm. Moreover, 2,7‐dichlorofluorescin and ferricytochrome c (Cyt Fe3+) have been used to detect the formation of hydrogen peroxide and superoxide radical anion, which reduces Fe3+ of the ferricytochrome to Fe2+, respectively. 相似文献
164.
165.
Aysun apc Mlanie M. Lorion Hui Wang Nina Simon Maria Leidenberger Mariana C. BorgesSilva Diogo R. M. Moreira Yongping Zhu Yuqing Meng Jia Yun Chen Yew Mun Lee Oliver Friedrich Barbara Kappes Jigang Wang Lutz Ackermann Svetlana B. Tsogoeva 《Angewandte Chemie (International ed. in English)》2019,58(37):13161-13161
166.
Lien Vermeir Arnout Declerck Chak Ming To Barbara Kerkaert Paul Van der Meeren 《Magnetic resonance in chemistry : MRC》2019,57(9):674-685
A time-domain 1H nuclear magnetic resonance relaxometry method was elaborated for the rapid microstructural characterization of mozzarella cheese. For this purpose, there is a strong need to know how the experimentally determined T2 relaxation time distribution can be related to specific constituents in mozzarella. In this study, a detailed investigation is offered for fresh and aged low-moisture mozzarella cheese, often applied as a pizza cheese, by application of both a conventional Carr–Purcell–Meiboom–Gill (CPMG) sequence and a free-induction decay CPMG (FID-CPMG) sequence. The relaxation behavior was further elucidated by addition of deuterium oxide and by mild heat treatment of samples. The relaxation times of water protons in mozzarella were found to range from a few microseconds to some tens of milliseconds (in aged mozzarella) or to about hundred milliseconds (in fresh mozzarella). The upper limit of the T2 distribution can even be extended to the seconds range upon releasing water protons from the mozzarella matrix using a mild heat treatment or upon addition of deuterated water. Both stimuli also provided evidence for the absorption of water into the cheese matrix. The potential release and uptake of water demonstrated that mozzarella acts as a very dynamic system during production and storage. The detected differences in the behavior of the water fraction between fresh and aged low-moisture mozzarella might be utilized to study the influence of either production and/or storage conditions on the cheese ripening process. 相似文献
167.
Andrzej Okuniewski Jaroslaw Chojnacki Katarzyna Baranowska Barbara Becker 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(2):195-198
Two new dialkylammonium thiosulfates, namely bis(diisopropylammonium) thiosulfate, 2C6H16N+·S2O32−, (I), and bis(tert‐butylammonium) thiosulfate, 2C4H12N+·S2O32−, (II), have been characterized. The secondary ammonium salt (I) crystallizes with Z = 4, while the primary ammonium salt (II), with more hydrogen‐bond donors, crystallizes with Z = 8 and a noncrystallographic centre of inversion. In both salts, the organic cations and thiosulfate anions are linked within extensive N—H...O and N—H...S hydrogen‐bond networks, forming extended two‐dimensional layers. Layers are parallel to (10) in (I) and to (002) in (II), and have a polar interior and a nonpolar hydrocarbon exterior. The layered structure and hydrogen‐bond motifs observed in (I) and (II) are similar to those in related ammonium sulfates. 相似文献
168.
169.
Barbara Szafran Jan Pawlaczyk 《Journal of inclusion phenomena and macrocyclic chemistry》1995,23(4):277-288
The 1 : 1 inclusion complex involving sulfafurazole (SF) and-cyclodextrin (-CD) is prepared by the freeze-drying method and characterized on the basis of its chemical analysis, thermal behavior, infrared spectrum, X-ray powder pattern and13C NMR spectrum in DMSO-d6 solution. The stability constant of the inclusion complex was determined by the solubility method. The effect of cyclodextrin on the UV absorption spectrum of sulfafurazole was also observed. 相似文献
170.
Barbara Pilawa Andrzej B. Wi
ckowski Barbara Trzebicka 《Radiation Physics and Chemistry》1995,45(6):899-908
The multi-component structure of the EPR spectra of Polish medium metamorphosed coal, its macerals and their pyridine extractrion products were analyzed. The bes numerical approximation of the EPR spectra for exinite, vitrinite and their extraction residues was obtained when two Lorentz and one Gauss curve were chosen for calculation. The EPR spectra of inertinite and its residue are superposition of two Lorentz lines. The EPR spectra of the extracts are fitted by single Lorentz lines. Four groups of paramagnetic centres which give the EPR signals with different ranges of linewidths are present in the macerals and the extraction products. Paramagnetic centres with the narrow EPR lines are present not only in inertinites, but also in exinites and vitrinites. Each of the four types of paramagnetic centres is present in macromolecular and molecular part of the macerals. As was expected, four component lines were detected for the EPR spectra of the coal and its residue. Paramagnetic centres responsible for the broad lines are located on structures consisting of a few aromatic rings. Paramagnetic centres of large aromatic structures are responsible for the narrow lines. 相似文献