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361.
Ondrej Uhlik Mary-Cathrine Leewis Michal Strejcek Lucie Musilova Martina Mackova Mary Beth Leigh Tomas Macek 《Biotechnology advances》2013
Microbial biodegradation and biotransformation reactions are essential to most bioremediation processes, yet the specific organisms, genes, and mechanisms involved are often not well understood. Stable isotope probing (SIP) enables researchers to directly link microbial metabolic capability to phylogenetic and metagenomic information within a community context by tracking isotopically labeled substances into phylogenetically and functionally informative biomarkers. SIP is thus applicable as a tool for the identification of active members of the microbial community and associated genes integral to the community functional potential, such as biodegradative processes. The rapid evolution of SIP over the last decade and integration with metagenomics provide researchers with a much deeper insight into potential biodegradative genes, processes, and applications, thereby enabling an improved mechanistic understanding that can facilitate advances in the field of bioremediation. 相似文献
362.
Ingunn S. Riddervold Søren K. Kjærgaard Gert F. Pedersen Niels T. Andersen Ondrej Franek Anders D. Pedersen Torben Sigsgaard Robert Zachariae Lars Mølhave Jørgen B. Andersen 《Bioelectromagnetics》2010,31(5):380-390
Current radio frequency radiation exposure guidelines rest on well‐established thermal effects. However, recent research into analogue and digital transmission fields at levels covered by the exposure guidelines has indicated possible detrimental effects on human cognitive performance. To investigate this, we conducted a controlled climate chamber study of possible changes in cognitive performance in healthy volunteers exposed to transmission signals from TETRA hand portables (TETRA handsets). The trial deployed a balanced, randomized, double‐blinded cross‐over design. Performance on different paper‐and‐pencil, auditory and computer‐based cognitive tasks was monitored in 53 male volunteers (mean age 36.41 years, SD 8.35) during 45‐min exposure to a TETRA handset and sham control signals remotely controlled from a laboratory more than 100 km away. The main cognitive outcome was the Trail Making B (TMB) test. In addition, the participants completed a computer‐based questionnaire measuring self‐reported psychological and physical symptoms. No statistically significant differences (P < 0.05) between the TETRA and sham conditions were found for either TMB (estimated difference 3.8%, confidence interval (CI) ?1.6% to 9.2%) or any of the remaining cognitive tasks or symptoms. In conclusion, we found no evidence that brief exposure to hand‐held TETRA transmitters' affects human cognitive function or subjective symptoms. Bioelectromagnetics 31:380–390, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
363.
The geometric and electronic structure of donor-acceptor complexes of TCNE with aniline, o-, m- and p- aminopyridines and pyridine has been studied in gas phase and in solution using CC2, TDDFT and CIS methods. Concerning interaction energy between particular donor and TCNE acceptor it is fairly described by both CC2 (MP2) and DFT-D approaches. Transition energies in gas phase calculated by CC2 approach are in good agreement with available experimental data for aniline. TDDFT calculations with LC-BLYP functional (with standard value of range separation factor μ?=?0.47) gives transition energies too high although not as high as CIS. The red solvent shifts, calculated by PCM model with CIS method are qualitative correct, but error in the range of 0.1-0.2 eV should be expected. 相似文献
364.
365.
Liisa M. Hirvonen Kai Wicker Ondrej Mandula Rainer Heintzmann 《European biophysics journal : EBJ》2009,38(6):807-812
Due to diffraction, the resolution of imaging emitted light in a fluorescence microscope is limited to about 200 nm in the
lateral direction. Resolution improvement by a factor of two can be achieved using structured illumination, where a fine grating
is projected onto the sample, and the final image is reconstructed from a set of images taken at different grating positions.
Here we demonstrate that with the help of a spatial light modulator, this technique can be used for imaging slowly moving
structures in living cells.
This article has been submitted as a contribution to the Festschrift entitled “Uncovering cellular sub-structures by light microscopy” in honour of Professor Cremer’s 65th birthday. 相似文献
366.
Ondrej Chlumsky Sabina Purkrtova Hana Michova Viviana Svarcova Petr Slepicka Dominik Fajstavr 《Biofouling》2020,36(2):222-233
AbstractThe antimicrobial activity of gold and silver nanoparticles (AuNPs, AgNPs), chitosan (CS) and their combinations was established by determining the minimum inhibitory concentration for planktonic (MICPC80) and biofilm growth (MICBC80), for biofilm formation (MICBF80), metabolic activity (MICBM80) and reduction (MICBR80), and for the metabolic activity of preformed biofilm (MICMPB80). Biofilms were quantified in microtitre plates by crystal violet staining and metabolic activity was evaluated by the MTT assay. Chitosan effectively suppressed biofilm formation (0.31–5?mg ml?1) in all the tested strains, except Salmonella enterica Infantis (0.16–2.5?mg ml?1) where CS and its combination with AgNPs induced biofilm formation. Nanoparticles inhibited biofilm growth only when the highest concentrations were used. Even though AuNPs, AgNPs and CS were not able to remove biofilm mass, they reduced its metabolic activity by at least 80%. The combinations of nanoparticles with CS did not show any significant positive synergistic effect on the tested target properties. 相似文献
367.
368.
Jindra Windrichova Pavel Broz Radka Fuchsova Ondrej Topolcan Ladislav Pecen Otto Mayer Radek Kucera 《Journal of Medical Biochemistry》2021,40(3):277
BackgroundTo compare four automated immunoassays for the measurement of 25(OH)-vitamin D (25-OHD) and to assess the impact on the results obtained from a healthy population.MethodsWe analysed 100 serum samples on Unicel DxI 800 (Beckman Coulter), Architect i1000 (Abbott), Cobas e411 (Roche) and Liaison XL (DiaSorin). Passing-Bablok regression and Bland-Altman plots were used for method comparison. In order to categorise the obtained values, results were categorised into the following groups: 0-25 nmol/L, 25-50 nmol/L, 50-75 nmol/L and above 75 nmol/L and compared. The percentage of samples below 75 nmol/L, and below 50 nmol/L was then calculated for every method.ResultsAccording to paired comparisons, each method differs from others (p<0.0001) except Cobas vs Architect, which do not show a statistically significant difference (p=0.39). The strongest correlation was found between Liaison and Architect (ρ=0.94, p<0.0001). The percentage of samples below the recommended value of 75 nmol/L were: 70% (Architect), 92% (Liaison), 71% (Cobas) and 89% (Unicel). The percentage of samples below the value of 50 nmol/L were: 17% (Architect), 55% (Liaison), 28% (Cobas) and 47% (Unicel).ConclusionsThe observed differences stem from the use of different analytical systems for 25-OHD concentration analysis and can result in different outcomes. The recommended values should be established for each assay in accordance with the data provided by the manufacturer or in the laboratory, in accordance with proper standardisation. 相似文献
369.
Jimmy Moses Marcell K. Peters Yvonne Tiede Ondrej Mottl David A. Donoso Nina Farwig Tom M. Fayle Vojtech Novotny Nathan J. Sanders Petr Klimes 《Global Ecology and Biogeography》2023,32(12):2212-2229
Aim
Many studies demonstrate that climate limits invertebrates along tropical elevational gradients, but we have only a rudimentary understanding of the role of nutrient limitation and climatic seasonality. Here we examined the relationships between ant community structure, nutrient use and season along three undisturbed elevational gradients, each from a different continent.Location
Ecuador (South America), Papua New Guinea (PNG: Oceania), Tanzania (Africa).Time period
2011–2014.Major taxa studied
Ants.Methods
Along each of the three gradients, we placed six distinct nutrient types (amino acid, sucrose, sucrose + amino acid, lipid, NaCl, H2O). In total, we distributed 2370 baits at 38 sites from 203 m to 3972 m. We used generalized linear models to test for the effects of elevation and season on ant species richness and activity and relative nutrient use. We also tested if changes in ant trophic guilds corresponded to changes in the use of particular nutrients.Results
Both species richness and activity decreased with elevation along each gradient. However, there were significant interaction effects among elevation, region and season, as ant activity in the dry season was higher in Ecuador and Tanzania but lower in PNG. Relative nutrient use varied among regions: ant preference for some nutrients changed with increasing elevation in Ecuador (decrease in lipid use) and Tanzania (decrease in amino acid and H2O use), while season affected nutrient use in PNG. There were common trends in trophic guilds along the three elevational gradients (e.g. proportional increase of predators), but these did not explain most of the nutrient use patterns.Main conclusion
While the structure of ant communities changed similarly with elevation, both the seasonal and elevational effects on nutrient use by ants differed between continents. We argue that regional differences in climate and nutrient availability rather than ant functional composition shape nutrient use by ants. 相似文献370.