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161.
The removal and determination of trimethylsilanol (TMSOH) in landfill gas has been studied before and after the special E3000-ITC System. The system works according to principle of temperature swing. The performance of TMSOH and humidity removal was 20% and more than 90%, respectively. The six of active carbons and impinger method were tested on the full-scale landfill in Poland for TMSOH and siloxanes determination. The extraction method and absorption in acetone were used. The concentration of TMSOH and siloxanes were found in range from 23.6 to 29.2 mg/m3 and from 18.0 to 38.9 mg/m3, respectively. The content of TMSOH in biogas originating from landfill was 41% out of all siloxanes. Moreover, the used system is alternative to other existing technique of landfill gas purification. 相似文献
162.
Recent studies indicated that there is a direct link between central carbon metabolism (CCM) and initiation and elongation of DNA replication in Eschericha coli. Namely, effects of certain mutations in genes coding for replication proteins (dnaA, dnaB, dnaE, dnaG, and dnaN) could be specifically suppressed by deletions of some genes, whose products are involved in CCM reactions (pta, ackA, pgi, tktB, and gpmA). Here, we demonstrate that the link between CCM and DNA synthesis can be extended to the DNA replication fidelity, as we report changes of the mutator phenotypes of E. coli dnaQ49 and dnaX36 mutants (either suppression or enhancement) by dysfunctions of zwf, pta, ackA, acnB, and icdA genes. Overexpression of appropriate wild-type CCM genes in double mutants resulted in reversions to the initial mutator phenotypes, indicating that the effects were specific. Moreover, the observed suppression and enhancement effects were not caused by changes in bacterial growth rates. These results suggest that there is a genetic correlation between CCM and DNA replication fidelity in E. coli, apart from the already documented link between CCM and DNA replication initiation control and elongation efficiency. 相似文献
163.
Janowska B Kurpios-Piec D Prorok P Szparecki G Komisarski M Kowalczyk P Janion C Tudek B 《Mutation research》2012,729(1-2):41-51
One of the major lipid peroxidation products trans-4-hydroxy-2-nonenal (HNE), forms cyclic propano- or ethenoadducts bearing six- or seven-carbon atom side chains to G > C ? A > T. To specify the role of SOS DNA polymerases in HNE-induced mutations, we tested survival and mutation spectra in the lacZα gene of M13mp18 phage, whose DNA was treated in vitro with HNE, and which was grown in uvrA? Escherichia coli strains, carrying one, two or all three SOS DNA polymerases. When Pol IV was the only DNA SOS polymerase in the bacterial host, survival of HNE-treated M13 DNA was similar to, but mutation frequency was lower than in the strain containing all SOS DNA polymerases. When only Pol II or Pol V were present in host bacteria, phage survival decreased dramatically. Simultaneously, mutation frequency was substantially increased, but exclusively in the strain carrying only Pol V, suggesting that induction of mutations by HNE is mainly dependent on Pol V. To determine the role of Pol II and Pol IV in HNE induced mutagenesis, Pol II or Pol IV were expressed together with Pol V. This resulted in decrease of mutation frequency, suggesting that both enzymes can compete with Pol V, and bypass HNE-DNA adducts in an error-free manner. However, HNE-DNA adducts were easily bypassed by Pol IV and only infrequently by Pol II.Mutation spectrum established for strains expressing only Pol V, showed that in uvrA? bacteria the frequency of base substitutions and recombination increased in relation to NER proficient strains, particularly mutations at adenine sites. Among base substitutions A:T → C:G, A:T → G:C, G:C → A:T and G:C → T:A prevailed.The results suggest that Pol V can infrequently bypass HNE-DNA adducts inducing mutations at G, C and A sites, while bypass by Pol IV and Pol II is error-free, but for Pol II infrequent. 相似文献
164.
Cadmium-induced changes in genomic DNA-methylation status increase aneuploidy events in a pig Robertsonian translocation model 总被引:1,自引:0,他引:1
Inglot P Lewinska A Potocki L Oklejewicz B Tabecka-Lonczynska A Koziorowski M Bugno-Poniewierska M Bartosz G Wnuk M 《Mutation research》2012,747(2):182-189
Although cadmium is a well-established human carcinogen, the mechanisms by which it induces cancer are poorly understood. It is suggested that cadmium-mediated carcinogenesis may include the modulation of gene expression and signal-transduction pathways, interference with antioxidant enzymes, inhibition of DNA repair and DNA methylation, and induction of apoptosis. Nevertheless, no predominant mechanism playing a role in metal-induced carcinogenesis has been reported. In the present study, we used a pig Robertsonian translocation model, which is a cross between a wild boar and domestic pig resulting in Robertsonian translocation (37,XX,der15;17 or 37,XY,der15;17), to determine the role of cadmium sulfate in the modulation of genomic DNA-methylation status and the induction of aneuploidy. We found a cadmium-mediated increase in aneuploidy within chromosome group A and C, but not within chromosome group D containing the translocated chromosome der15,17 which indicates that translocated chromosome is not more prone to chromosomal aberrations than are other chromosomes. We suggest that cadmium-induced aneuploidy (up to 5-μM concentration) may be mediated by global DNA hypermethylation as monitored with HPLC and 5-mdC immunostaining. In addition, the cyto- and genotoxic potential of cadmium was evaluated. Cadmium sulfate was able to induce apoptosis, inhibit cell-proliferative status and expression of nucleolar organizer regions (NORs), and increase oxidative DNA damage (8-oxoG content). 相似文献
165.
In the development of ischemia/reperfusion (I/R) injury, the role of the myosin light chain (MLC) phosphorylation has been given increased consideration. ML-7, a MLC kinase inhibitor, has been shown to protect cardiac function from I/R, however the exact mechanism remains unclear. Isolated rat hearts were perfused under aerobic conditions (controls) or subjected to I/R in the presence or absence of ML-7. Continuous administration of ML-7 (5 μM) from 10 min before onset of ischemia to the first 10 min of reperfusion resulted in significant recovery of heart contractility. Analysis of gels from two-dimensional electrophoresis revealed eight proteins with decreased levels in I/R hearts. Six proteins are involved in energy metabolism:ATP synthase beta subunit, cytochrome b-c1 complex subunit 1, 24-kDa mitochondrial NADH dehydrogenase, NADH dehydrogenase [ubiquinone] iron-sulfur protein 8, cytochrome c oxidase subunit, and succinyl-CoA ligase subunit. The other two proteins with decreased levels in I/R hearts are: peroxiredoxin-2 and tubulin. Administration of ML-7 increased level of succinyl-CoA ligase, key enzyme involved in the citric acid cycle. The increased level of succinyl-CoA ligase in I/R hearts perfused with ML-7 suggests that the cardioprotective effect of ML-7, at least partially, also may involve increase of energy production. 相似文献
166.
Andrzej Wuczyński Bartosz Smyk Paweł Kołodziejczyk Wiesław Lenkiewicz Grzegorz Orłowski Andrzej Pola 《Central European Journal of Biology》2012,7(3):495-506
South-western Poland belongs to the key staging areas for geese in Europe, supporting some 100000 birds in recent years. We
compared goose counts conducted in the 1970s, 1990s and during 2009–2011 in this region, and linked the findings to the recent
assessments of trends in the flyway-populations. Numbers increased several dozen times between the first two counts and have
stabilized to the present. More than 14% of the flyway Tundra Bean Goose (Anser fabalis rossicus) stopped over in SW Poland on passage. Smaller numbers of White-fronted Goose (A. albifrons), Greylag Goose (A. anser), and four other rarer species, have all increased since the 1970s. The likely factors responsible for these changes are
mild weather conditions, increased availability of large water bodies and shifts in winter ranges of particular species. Temporal
mismatch between SW Poland and the total flyways in Bean and White-fronted Geese was recorded when we compared the long-term
and the short-term population trends. Increasing reports of other species in SW Poland match the general tendencies in Europe.
These data document that regional trends are not a simple reflection of those in flyways as a whole. To understand changes
in goose populations a re-established international count network is desired. 相似文献
167.
Joanna Czarnecka Grzegorz Orłowski Jerzy Karg 《Central European Journal of Biology》2012,7(5):895-901
The role of frugivorous birds in dispersal of the seeds of fleshy-fruited plants is well understood, but other groups of birds
like granivores and omnivores can also act as vectors, especially in the process of non-standard dispersal. In this study
we examined the role of two widely distributed birds (the Eurasian Blackbird, Turdus merula, and the Black Redstart, Phoenicurus ochruros) in seed dispersal. We analyzed the content of 279 droppings of the Black Redstart collected between July and October and
85 droppings of the Eurasian Blackbird collected during January. In total we found 366 seeds, representing 11 plant taxa,
in the faecal samples; 93% of the seeds belonged to fleshy-fruited species. The most numerous were two native taxa, Sambucus racemosa/nigra, in summer and autumn, Crataegus monogyna in winter, and one alien species Morus alba, which is dispersed in summer. We also found seeds of four dry-fruited species; the most interesting of which was the presence
of anemochorous seeds of Solidago gigantea (a highly invasive alien species). The seeds were found only in droppings of the Eurasian Blackbird. Considering the obtained
results the need for further studies on bird-plant interactions should be a priority. 相似文献
168.
Marek Stibal Jemma L. Wadham Grzegorz P. Lis Jon Telling Richard D. Pancost Ashley Dubnick Martin J. Sharp Emily C. Lawson Catriona E. H. Butler Fariha Hasan Martyn Tranter Alexandre M. Anesio 《Global Change Biology》2012,18(11):3332-3345
Subglacial environments are largely anoxic, contain organic carbon (OC) overridden by glacier ice during periods of advance, and harbour active microbial communities. This creates favourable conditions for OC degradation via methanogenesis. It has been hypothesized that OC beneath ice sheets is converted to methane (CH4) and may be released to the atmosphere during retreat. However, there are limited data available to support this contention. Here, we present new data on the abundance, diversity and activity of methanogenic archaea and the amount and character of OC in subglacial sediments from Arctic and Antarctic glacial systems based on different substrate types. We employed long‐term laboratory incubations to quantify the CH4 production potential in different subglacial settings. Significant numbers of methanogens (up to 7 × 104 cells g?1) were detected in the samples and clones of Methanomicrobiales and Methanosarcinales were identified in clone libraries. Long lag periods (up to >200 days) were observed before significant CH4 concentrations were measured. We report order of magnitude differences in rates of CH4 production (101–105 fmol g?1 d?1) in different subglacial sediments, reflecting contrasts in the origin of the sediment and the OC character. Hence, we predict that contrasting rates of CH4 production are likely to occur beneath glaciers and ice sheets that overran different types of substrate. We subsequently estimated the potential for CH4 production beneath the Laurentide/Inuitian/Cordilleran and Fennoscandian Ice Sheets during a typical 85 ka Quaternary glacial/interglacial cycle. CH4 production from lacustrine‐derived OC is likely to be an order of magnitude higher (~6.3–27 Pg C) than that from overridden soils (~0.55–0.68 Pg C), possibly due to a difference in lability between lacustrine and soil OC. While representing a fraction of the entire OC pool (~418–610 Pg C), this finding highlights the importance of considering the character of different OC pools when calculating subglacial CH4 production. 相似文献
169.
Co-crystallization experiments of proteins with nucleic acids do not guarantee that both components are present in the crystal. We have previously developed DIBER to predict crystal content when protein and DNA are present in the crystallization mix. Here, we present RIBER, which should be used when protein and RNA are in the crystallization drop. The combined RIBER/DIBER suite builds on machine learning techniques to make reliable, quantitative predictions of crystal content for non-expert users and high-throughput crystallography. 相似文献
170.
Marek Kiliszek Beata Burzynska Marcin Michalak Monika Gora Aleksandra Winkler Agata Maciejak Agata Leszczynska Ewa Gajda Janusz Kochanowski Grzegorz Opolski 《PloS one》2012,7(11)