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11.
Beecroft NJ Zhao F Varcoe JR Slade RC Thumser AE Avignone-Rossa C 《Applied microbiology and biotechnology》2012,93(1):423-437
The performance and dynamics of the bacterial communities in the biofilm and suspended culture in the anode chamber of sucrose-fed
microbial fuel cells (MFCs) were studied by using denaturing gradient gel electrophoresis (DGGE) of PCR-amplified partial
16S rRNA genes followed by species identification by sequencing. The power density of MFCs was correlated to the relative
proportions of species obtained from DGGE analysis in order to detect bacterial species or taxonomic classes with important
functional role in electricity production. Although replicate MFCs showed similarity in performance, cluster analysis of DGGE
profiles revealed differences in the evolution of bacterial communities between replicate MFCs. No correlation was found between
the proportion trends of specific species and the enhancement of power output. However, in all MFCs, putative exoelectrogenic
denitrifiers and sulphate-reducers accounted for approximately 24% of the bacterial biofilm community at the end of the study.
Pareto–Lorenz evenness distribution curves extracted from the DGGE patterns obtained from time course samples indicated community
structures where shifts between functionally similar species occur, as observed within the predominant fermentative bacteria.
These results suggest the presence of functional redundancy within the anodic communities, a probable indication that stable
MFC performance can be maintained in changing environmental conditions. The capability of bacteria to adapt to electricity
generation might be present among a wide range of bacteria. 相似文献
12.
H Hackstein N Hagel A Knoche S Kranz J Lohmeyer W von Wulffen O Kershaw AD Gruber G Bein N Baal 《PloS one》2012,7(8):e43320
The TLR7 agonist imiquimod has been used successfully as adjuvant for skin treatment of virus-associated warts and basal cell carcinoma. The effects of skin TLR7 triggering on respiratory leukocyte populations are unknown. In a placebo-controlled experimental animal study we have used multicolour flow cytometry to systematically analyze the modulation of respiratory leukocyte subsets after skin administration of imiquimod. Compared to placebo, skin administration of imiquimod significantly increased respiratory dendritic cells (DC) and natural killer cells, whereas total respiratory leukocyte, alveolar macrophages, classical CD4+ T helper and CD8+ T killer cell numbers were not or only moderately affected. DC subpopulation analyses revealed that elevation of respiratory DC was caused by an increase of respiratory monocytic DC and CD11b(hi) DC subsets. Lymphocyte subpopulation analyses indicated a marked elevation of respiratory natural killer cells and a significant reduction of B lymphocytes. Analysis of cytokine responses of respiratory leukocytes after stimulation with Klebsiella pneumonia indicated reduced IFN-γ and TNF-α expression and increased IL-10 and IL-12p70 production after 7 day low dose skin TLR7 triggering. Additionally, respiratory NK cytotoxic activity was increased after 7d skin TLR7 triggering. In contrast, lung histology and bronchoalveolar cell counts were not affected suggesting that skin TLR7 stimulation modulated respiratory leukocyte composition without inducing overt pulmonary inflammation. These data suggest the possibility to modulate respiratory leukocyte composition and respiratory cytokine responses against pathogens like Klebsiella pneumonia through skin administration of a clinically approved TLR7 ligand. Skin administration of synthetic TLR7 ligands may represent a novel, noninvasive means to modulate respiratory immunity. 相似文献
13.
Holger Hackstein Andreas Wachtendorf Sabine Kranz Jürgen Lohmeyer Gregor Bein Nelli Baal 《Respiratory research》2012,13(1):1-13
Background
Inbred mouse strains are used in different models of respiratory diseases but the variation of critical respiratory leukocyte subpopulations across different strains is unknown.Methods
By using multiparameter flow cytometry we have quantitated respiratory leukocyte subsets including dendritic cells subpopulations, macrophages, classical T and B cells, natural killer cells, γδTCR+ T cells and lineage-negative leukocytes in the five most common inbred mouse strains BALB/c, C57BL/6, DBA/2, 129SV and C3H. To minimize confounding environmental factors, age-matched animals were received from the same provider and were housed under identical specific-pathogen-free conditions.Results
Results revealed significant strain differences with respect to respiratory neutrophils (p=0.005; up to 1.4 fold differences versus C57BL/6 mice), eosinophils (p=0.029; up to 2.7 fold), certain dendritic cell subsets (p≤0.0003; up to 3.4 fold), T (p<0.001; up to 1.6 fold) and B lymphocyte subsets (p=0.005; up to 0.4 fold), γδ T lymphocytes (p=0.003; up to 1.6 fold), natural killer cells (p<0.0001; up to 0.6 fold) and lineage-negative innate leukocytes (p≤0.007; up to 3.6 fold). In contrast, total respiratory leukocytes, macrophages, total dendritic cells and bronchoalveolar lavage leukocytes did not differ significantly. Stimulation of respiratory leukocytes via Toll-like receptor 4 and 9 as well as CD3/CD28 revealed significant strain differences of TNF-α and IL-10 production.Conclusion
Our study demonstrates significant strain heterogeneity of respiratory leukocyte subsets that may impact respiratory immunity in different disease models. Additionally, the results may help identification of optimal strains for purification of rare respiratory leukocyte subsets for ex vivo analyses. 相似文献14.
15.
Nelli Mnatsakanyan Karine Bagramyan Armen Trchounian 《Cell biochemistry and biophysics》2004,41(3):357-365
Fermenting Escherichia coli is able to produce formate and molecular hydrogen (H2) when grown on glucose. H2 formation is possessed by two hydrogenases, 3 (Hyd-3) and 4 (Hyd-4), those, in conjunction with formate dehydrogenase H (Fdh-H),
constitute distinct membrane-associated formate hydrogenylases. At slightly alkaline pH (pH 7.5), the production of H2 was found to be dependent on Hyd-4 and the F0F1-adenosine triphosphate (ATPase), whereas external formate increased the activity of Hyd-3. In this study with cells grown
without and with external formate H2 production dependent on pH was investigated. In both types of cells, H2 production was increased after lowering of pH. At acidic pH (pH 5.5), this production became insensitive either to N,N′-dicyclohexylcarbodiimide or to osmotic shock and it became largely dependent on Fdh-H and Hyd-3 but not Hyd-4 and the F0F1-ATPase. The results indicate that Hyd-3 has a major role in H2 production at acidic pH independently on the F0F1-ATPase. 相似文献
16.
17.
Nelli Mnatsakanyan Gisela Beutner George A. Porter Kambiz N. Alavian Elizabeth A. Jonas 《Journal of bioenergetics and biomembranes》2017,49(1):13-25
Neurons experience high metabolic demand during such processes as synaptic vesicle recycling, membrane potential maintenance and Ca2+ exchange/extrusion. The energy needs of these events are met in large part by mitochondrial production of ATP through the process of oxidative phosphorylation. The job of ATP production by the mitochondria is performed by the F1FO ATP synthase, a multi-protein enzyme that contains a membrane-inserted portion, an extra-membranous enzymatic portion and an extensive regulatory complex. Although required for ATP production by mitochondria, recent findings have confirmed that the membrane-confined portion of the c-subunit of the ATP synthase also houses a large conductance uncoupling channel, the mitochondrial permeability transition pore (mPTP), the persistent opening of which produces osmotic dysregulation of the inner mitochondrial membrane, uncoupling of oxidative phosphorylation and cell death. Recent advances in understanding the molecular components of mPTP and its regulatory mechanisms have determined that decreased uncoupling occurs in states of enhanced mitochondrial efficiency; relative closure of mPTP therefore contributes to cellular functions as diverse as cardiac development and synaptic efficacy. 相似文献
18.
Background
Previous work on the human auditory cortex has revealed areas specialized in spatial processing but how the neurons in these areas represent the location of a sound source remains unknown.Methodology/Principal Findings
Here, we performed a magnetoencephalography (MEG) experiment with the aim of revealing the neural code of auditory space implemented by the human cortex. In a stimulus-specific adaptation paradigm, realistic spatial sound stimuli were presented in pairs of adaptor and probe locations. We found that the attenuation of the N1m response depended strongly on the spatial arrangement of the two sound sources. These location-specific effects showed that sounds originating from locations within the same hemifield activated the same neuronal population regardless of the spatial separation between the sound sources. In contrast, sounds originating from opposite hemifields activated separate groups of neurons.Conclusions/Significance
These results are highly consistent with a rate code of spatial location formed by two opponent populations, one tuned to locations in the left and the other to those in the right. This indicates that the neuronal code of sound source location implemented by the human auditory cortex is similar to that previously found in other primates. 相似文献19.
20.
Timea Dergez Dénes Lőrinczy Franciska Könczöl Nelli Farkas Joseph Belagyi 《BMC structural biology》2007,7(1):41