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11.
Petr Michalek Simona Dostalova Hana Buchtelova Natalia Cernei Ludmila Krejcova David Hynek Vedran Milosavljevic Ana Maria Jimenez Jimenez Pavel Kopel Zbynek Heger Vojtech Adam 《Electrophoresis》2016,37(14):2025-2035
Annual epidemics of influenza cause death of hundreds of thousands people and they also have a significant economic impact. Hence, a need for fast and cheap influenza diagnostic method is arising. The conventional methods for an isolation of the viruses are time‐consuming and require expensive instrumentation as well as trained personnel. In this study, we modified the surface of nanomaghemite (γ‐Fe2O3) paramagnetic core with tetraethyl orthosilicate and (3‐aminopropyl)triethoxysilane and the resulting particles were utilized for the isolation of H7N7 influenza virions. Consequently, we designed γ‐Fe2O3 paramagnetic core modified with calcium tripolyphosphate which was employed for the isolation of viral nucleic acid after virion's lysis. Both of these procedures can be performed rapidly in less than 10 min and, in combination with the RT‐PCR, the whole influenza detection can be shortened to few hours. Moreover, the whole protocol could be easily automated and/or miniaturized, and thus can serve as a basis for use in a lab‐on‐a‐chip device. We assume that magnetic isolation is an exceptional procedure which can significantly accelerate the diagnostic possibilities of a broad spectrum of diseases. 相似文献
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Dr. Stefanie Vogel Kenny Ebel Dr. Robin M. Schürmann Dr. Christian Heck Dr. Till Meiling Dr. Aleksandar R. Milosavljevic Dr. Alexandre Giuliani Dr. Ilko Bald 《Chemphyschem》2019,20(6):823-830
DNA is effectively damaged by radiation, which can on the one hand lead to cancer and is on the other hand directly exploited in the treatment of tumor tissue. DNA strand breaks are already induced by photons having an energy below the ionization energy of DNA. At high photon energies, most of the DNA strand breaks are induced by low-energy secondary electrons. In the present study we quantified photon and electron induced DNA strand breaks in four different 12mer oligonucleotides. They are irradiated directly with 8.44 eV vacuum ultraviolet (VUV) photons and 8.8 eV low energy electrons (LEE). By using Si instead of VUV transparent CaF2 as a substrate the VUV exposure leads to an additional release of LEEs, which have a maximum energy of 3.6 eV and can significantly enhance strand break cross sections. Atomic force microscopy is used to visualize strand breaks on DNA origami platforms and to determine absolute values for the strand break cross sections. Upon irradiation with 8.44 eV photons all the investigated sequences show very similar strand break cross sections in the range of 1.7–2.3×10−16 cm2. The strand break cross sections for LEE irradiation at 8.8 eV are one to two orders of magnitude larger than the ones for VUV photons, and a slight sequence dependence is observed. The sequence dependence is even more pronounced for LEEs with energies <3.6 eV. The present results help to assess DNA damage by photons and electrons close to the ionization threshold. 相似文献
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In our recent Letter1 a line of text was dropped in printing. On p. 2024 the beginning of the paragraph above Fig. 3 should read as follows: "Surprisingly, the 0.5-muJ pulse energy used in these microexplosions...". 相似文献
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Nejdl Lukas Zitka Jan Mravec Filip Milosavljevic Vedran Zitka Ondrej Kopel Pavel Adam Vojtech Vaculovicova Marketa 《Mikrochimica acta》2017,184(5):1489-1497
Microchimica Acta - The authors report on a systematic study on the low-cost, low-temperature, and fast synthesis of water soluble quantum dots (QDs) stabilized by mercaptosuccinic acid by UV... 相似文献
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Schaaf P. Milosavljevic M. Dhar S. Bibic N. Lieb K.-P. Wölz M. Principi G. 《Hyperfine Interactions》2002,139(1-4):615-621
At present, there is an increasing interest in the iron di-silicide phase -FeSi2, which is supposed to be a direct band gap semiconductor and one of the most promising materials for silicon-based optoelectronics, e.g., light-emitting devices, solar cells, and photo detectors. But this phase is very difficult to be produced. Here, the successful direct synthesis of this phase by ion beam mixing of Fe/Si bilayers at temperatures in the range of 400 to 600°C is reported. The aim of the experiments was to achieve a complete reaction of the deposited Fe layer with the Si substrate that results in the formation of a pure, single-phased -FeSi2 surface layer. The obtained silicide layers, their structure and composition are investigated by conversion electron Mössbauer spectroscopy (CEMS), Rutherford backscattering spectrometry (RBS), and X-ray diffraction (XRD). The fraction of the -FeSi2 formed is determined by CEMS as function of ion species, energy, fluence and temperature. Complete growth and formation of a single-phased -FeSi2 layer was achieved by 205 keV Xe ion irradiation at a fluence of 2×1016 ions/cm2 at 600°C. 相似文献
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Vedran Milosavljevic Hoai Viet Nguyen Petr Michalek Amitava Moulick Pavel Kopel Rene Kizek Vojtech Adam 《Chemical Papers》2015,69(1):192-201
Nanoparticles as a progressively developing branch offer a tool for studying the interaction of carbon quantum dots (CQDs) with DNA. In this study, fluorescent CQDs were synthesized using citric acid covered with polyethylene glycol (PEG) as the source of carbon precursors. Furthermore, interactions between CQDs and DNA (double-stranded DNA and single-stranded DNA) were investigated by spectral methods, gel electrophoresis, and electrochemical analysis. Primarily, the fluorescent behavior of CQDs in the presence of DNA was monitored and major differences in the interaction of CQDs with tested single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) were observed at different amounts of CQDs (µg mL?1: 25, 50, 100, 250, 500). It was found that the interaction of ssDNA with CQDs had no significant influence on the CQDs fluorescence intensity measured at the excitation wavelengths of 280 nm, 350 nm, and 400 nm. However, in the presence of dsDNA, the fluorescence intensity of CQDs was significantly increased. Our results provide basic understanding of the interaction between CQDs and DNA. Such fabricated CQDs-DNA might be of great benefit for the emerging nanomaterials based biosensing methods. 相似文献
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Benoit R Saboungi ML Tréguer-Delapierre M Milosavljevic BH Meisel D 《The journal of physical chemistry. A》2007,111(42):10640-10645
Radiolytic reduction of BiOClO4 in aqueous solutions leads to the formation of bismuth clusters and larger nanoparticles. The mechanisms of redox reactions of the polycationic Bi(III) species that exist in the solution were investigated with pulse radiolysis. The kinetic and spectral properties of the transients formed by the reaction of these species with the primary radicals from water radiolysis are reported. The single-electron reduction product, Bi9(OH)224+, absorbs at lambdamax = 273 nm, while the OH adduct, Bi9(OH)235+, has a broad absorption spectrum with a maximum at 280 nm and a shoulder at 420 nm. Several rate constants were measured: k (e-aq + Bi9(OH)225+) = 1.2 x 1010 M-1 s-1 and k (OH + Bi9(OH)225+) = 1.5 x 109 M-1 s-1. The reduced species, Bi9(OH)224+ further reacts with (CH3)2COH radicals, but not with CH2C(CH3)2OH radicals from t-butanol, to produce a doubly reduced polynuclear species. A few reactions of the reduction of the Bi salt in the presence of poly(acrylic acid) are also described. In the presence of the polymer, a metal-polymer complex is formed prior to the irradiation, and the reduction reactions are significantly slowed down. 相似文献
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J. Kuljanin G. M. Vujicic M. Radojcic B. H. Milosavljevic 《Journal of Polymer Science.Polymer Physics》2000,38(13):1729-1733
The γ‐irradiation induced stepwise genesis of dimer, trimer, tetramer, and higher agglomerates in 1% ovalbumin aqueous solution was quantitatively followed by a SDS‐PAGE analytical method. The molecular mass distributions obtained in the dose interval form 0 to 2 kGy were used to calculate the gel dose by using Good's theory of cascade processes. The difference between the calculated value (3.5 kGy) and the measured value (8.5 kGy) is attributed to the competition between the agglomeration and the interradical conversion processes, which prevails in the higher dose region. It was estimated from the gel dose that 1 · 1020 of intermolecular bonds per dm3 were necessary to form a gel from 1% ovalbumin solution. A dynamic viscosity of the solution was also measured simultaneously. A simple semiempirical equation was developed containing only one parameter—gel dose, Dg—and it fits the viscosity–dose data fairly well. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 1729–1733, 2000 相似文献