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51.
Agnieszka Ulanowska Ewa Trawińska Piotr Sawrycki Bogusław Buszewski 《Journal of separation science》2012,35(21):2908-2913
Chemotherapy used as a treatment against lung cancer has influence on metabolic processes occurring in healthy cells. The changes of biochemical pathways proceeded inside cells might be observed in expired air. In the experiment, breath analysis was carried out before and after anticancer therapy. Expired air samples were collected from 22 patients with a biopsy confirmed lung cancer. Volatile organic compounds present in breath were analyzed by gas chromatography/mass spectrometry. For enrichment of analytes solid‐phase microextraction technique was applied. Eight fibers covered by different sorbents were tested. Carboxen‐polydimethylsiloxane fiber revealed the highest extraction efficiency in relation to analytes in breath. The data showed that cytostatic drugs increase the concentration of acetone and isoprene in the breath collected after chemotherapy. Volatile metabolites of administrated drugs were not identified in expired air. 相似文献
52.
Ewa Grela Michael Stich Amit K Chattopadhyay 《The European Physical Journal B - Condensed Matter and Complex Systems》2018,91(11):267
This is an epidemiological SIRV model based study that is designed to analyze the impact of vaccination in containing infection spread, in a 4-tiered population compartment comprised of susceptible, infected, recovered and vaccinated agents. While many models assume a lifelong protection through vaccination, we focus on the impact of waning immunization due to conversion of vaccinated and recovered agents back to susceptible ones. Two asymptotic states exist, the “disease-free equilibrium” and the “endemic equilibrium” and we express the transitions between these states as function of the vaccination and conversion rates and using the basic reproduction number. We find that the vaccination of newborns and adults have different consequences on controlling an epidemic. Also, a decaying disease protection within the recovered sub-population is not sufficient to trigger an epidemic at the linear level. We perform simulations for a parameter set mimicking a disease with waning immunization like pertussis. For a diffusively coupled population, a transition to the endemic state can proceed via the propagation of a traveling infection wave, described successfully within a Fisher-Kolmogorov framework. 相似文献
53.
Victoria E. Wright Fernando Castro-Gómez Ewa Jurneczko James C. Reynolds Andrew Poulton Steven D. R. Christie Perdita Barran Carles Bo Colin S. Creaser 《International Journal for Ion Mobility Spectrometry》2013,16(1):61-67
Collision cross sections (CCS) have been measured for three salen ligands, and their complexes with copper and zinc using travelling-wave ion mobility-mass spectrometry (TWIMS) and drift tube ion mobility-mass spectrometry (DTIMS), allowing a comparative size evaluation of the ligands and complexes. CCS measurements using TWIMS were determined using peptide and TAAH calibration standards. TWIMS measurements gave significantly larger CCS than DTIMS in helium, by 9 % for TAAH standards and 3 % for peptide standards, indicating that the choice of calibration standards is important in ensuring the accuracy of TWIMS-derived CCS measurements. Repeatability data for TWIMS was obtained for inter- and intra-day studies with mean RSDs of 1.1 % and 0.7 %, respectively. The CCS data obtained from IM-MS measurements are compared to CCS values obtained via the projection approximation, the exact hard spheres method and the trajectory method from X-ray coordinates and modelled structures using density functional theory (DFT) based methods. 相似文献
54.
Krzysztof Garman Ewa Olewnik Wojciech Czerwiński 《Journal of Thermal Analysis and Calorimetry》2013,111(1):799-805
This article presents the results of investigation into receiving amide modification agents of smectic clays, used as nanofillers in polymer nanocomposites. Prepared materials were obtained on the base of terephthalic and isophthalic acids and simple aliphatic amines. Such structure makes them good layered silicates modifying agents as well as makes them well affiliate to structure of polymers containing aromatic, carbonyl, amide, etc. groups. Obtained compounds were introduced into clays’ structure in protonated form, according to formulated method. Conducted research confirmed that the modification of montmorillonite clay (MMT) with received compounds had taken place. In order to establish that fact elementary analysis and X-ray diffraction (XRD) methods were used. Modificator molecules must display thermal resistance in full range of polymer processing temperatures. To investigate these properties the Thermogravimetric analysis (TG) of obtained compounds was carried out. These studies indicate that among the obtained compounds there were the ones with thermal stability over 523 K. Thermal resistance makes it possible for these substances to be used in poly(ethylene terephthalate) processing. 相似文献
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Miša Biro Darja Kavšek Jakub Karasiński Piotr Szwarczewski Ewa Bulska Darinka Brodnjak Vončina 《Central European Journal of Chemistry》2014,12(6):687-699
The development and validation of a reliable analytical procedure for the determination of selected metals (Cd, Cr, Cu, Pb, Zn and Mn) in sediments accumulated in the Utrata River (Poland) is described. The aqua regia extraction followed by inductively coupled plasma optical emission spectrometry (ICP-OES) was used for this purpose. The optimized analytical procedure was validated, and adequate quality control actions were implemented in order to provide reliable data. The precision under’ within-laboratory’ reproducibility conditions was estimated from duplicate analysis. Certified reference material (CRM) was used in order to evaluate the accuracy of the results regarding the sewage sludge amended soil CRM 143R. The detection limits for all elements of interest were well-below their content in the investigated sediment samples. The obtained reliable data could be used for assessment of the relationship between human economic activity in the past and the geochemical features of the sediments. 相似文献
59.
Jorna Kalim Thibaut Duhail Dr. Ewa Pietrasiak Dr. Elsa Anselmi Dr. Emmanuel Magnier Prof. Dr. Antonio Togni 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(8):2638-2642
The direct trifluoromethylation of a variety of aliphatic alcohols using a hypervalent iodosulfoximine reagent afforded the corresponding ethers in moderate to good yields (14–72 %). Primary, secondary, and even tertiary alcohols, including examples derived from natural products, underwent this transformation in the presence of catalytic amounts of zinc bis(triflimide). Typical reaction conditions involved a neat mixture of 6.0 equivalents of the alcohol with 1.0 equivalent of the reagent, with the majority of reactions complete within 2 h with 2.5 mol % of the Lewis acid catalyst. Furthermore, experimental evidence was provided that the C−O bond-forming process occurred via the coordination of the alcohol to the iodine atom and subsequent reductive elimination. 相似文献
60.
Przemysław Koźmiński Ewa Gniazdowska Leon Fuks Agata Oszczak 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(1):67-74
Easy and efficient way to modify of the C-terminus of the peptide using amino acid lysine has been proposed and experimentally
verified. The synthesis yield was high (≥85%) and it was found that reactions can be carried out even with microgram amounts
of the peptide. Using Fmoc-alanine (as the peptide model) with modified C-terminus the procedure of peptide labelling with
monovalent and trivalent 99mTc complexes has been elaborated. 相似文献