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The removal of polycyclic aromatic hydrocarbons by membrane bioreactor (MBR) under aerobic conditions had been studied using naphthalene (NAP) and phenanthrene (PHE) as model compounds. Three MBRs with submerged ultra-filtration hollow fiber membranes were operated applying different operational conditions during 6.5 months. Complete NAP and PHE removal was obtained applying loads of 7 gNAP kgTSS?1 day?1 and 0.5 gPHE kgTSS?1 day?1, while the organic loading rate was adjusted to 0.26 kgCOD kgTSS?1 day?1, with the biomass concentration being 6000 mgTSS L?1, the hydraulic retention time (HRT) 8 h and the solids retention time (SRT) 30 days. Load increases, as well as HRT and SRT reductions, affected the NAP and PHE removals. Biodegradation was found to be the major NAP and PHE removal mechanism. There was no NAP accumulation in the biomass. Low PHE quantities remain sorbed in the biomass and the contribution of the sorption in the removal of this compound was estimated to be less than 0.01 %. The volatilization does not contribute to the PHE removal in MBRs, but the contribution of NAP volatilization can reach up to 0.6 % when HRT of 8 h is applied. 相似文献
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Nedelcheva Simona Ivanovska Sofiya Durchova Mariya Koprinkova-Hristova Petia 《Cluster computing》2022,25(3):1637-1644
Cluster Computing - The paper presents a supercomputer parallel implementation of a brain inspired model combining a Python module simulating a layer of retina ganglion cells and NEST Simulator for... 相似文献
4.
Quideau S Varadinova T Karagiozova D Jourdes M Pardon P Baudry C Genova P Diakov T Petrova R 《化学与生物多样性》2004,1(2):247-258
Antiherpetic evaluation of five nonahydroxyterphenoyl-containing C-glycosidic ellagitannins, castalagin (1), vescalagin (2), grandinin (3), roburin B (5), and roburin D (7), was performed in cultured cells against four HSV-1 and HSV-2 strains, two of which were resistant to Acyclovir. All five ellagitannins displayed significant anti-HSV activities against the Acyclovir-resistant mutants, but the monomeric structures 1-3 were more active than the dimers 5 and 7. Vescalagin (2) stands out among the five congeners tested as the most potent and selective inhibitor, with an IC50 value in the subfemtomolar range and a selectivity index 5x10(5) times higher than that of Acyclovir. Molecular modeling was used to provide a rationale for the surprisingly lower activity profile of its epimer castalagin (1). These ellagitannins have promising potential as novel inhibitors in the search for non-nucleoside drugs active against Acyclovir-resistant herpes viruses. 相似文献
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Yucesoy Berran Vallyathan Val Landsittel Douglas P. Simeonova Petia Luster Michael I. 《Molecular and cellular biochemistry》2002,(1):219-224
Silicosis and coal workers' pneumoconiosis are complex multifactorial lung diseases whose etiopathogenesis are not well defined. It is generally accepted that fibrotic lung disorders are mediated by macrophage-derived cytokines and growth factors. There is evidence showing a crucial role for tumor necrosis factor- (TNF-) and interleukin-1 (IL-1) in inflammation caused by silica dust and in the transition from simple to progressive massive fibrosis. In this review we discuss genetic polymorphisms responsible for regulating the production of these proinflammatory cytokines and their role in modifying silicosis severity. 相似文献
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Relationship between type and age of the inoculum cultures and betalains biosynthesis by Beta vulgaris hairy root culture 总被引:1,自引:0,他引:1
From a study of the relationship between the type and age of the inocula, and the growth and biosynthesis of betalains in a Beta vulgaris hairy root culture, the best results were achieved with a 14 d inoculum grown in submerged culture giving 42 mg betalains (16 mg betacyanins and 26 betaxanthins) and 1.5 g dry biomass in 40 ml medium. 相似文献
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Petia Simeonova Nikolova Christian Zang Hans Pretzsch 《Trees - Structure and Function》2011,25(5):859-872
We show the potential of a new method combining tree-ring analyses on stems and on coarse roots of individual trees in order
to advance the understanding of growth dynamics in forest trees. To this end, we studied the root–shoot allometry of trees
and its dependence on site conditions. Along a gradient in water supply in Southern Germany from dry to moist sites we selected
43 Norway spruce trees (Picea abies [L.] H. Karst.) aged 65–100 years. Increment cores were taken from stem and main roots revealing aboveground and belowground
growth course over the last 34 years. Annual growth rates in roots and stems and their allometric relationships were applied
as surrogate variables for tree resource allocation to aboveground and belowground organs. The mean sensitivities of both
stem and root chronologies were found to be site-specific, and increased from the moist through the dry sites. No temporal
offset between aboveground and belowground growth reactions to climate conditions was found in Norway spruce at any of the
sites. These results suggest that the root–shoot allometry depends on the specific site conditions only at the driest site,
following the optimal biomass partitioning theory (the more restricted the water supply, the more organic matter allocation
into the belowground organs). 相似文献
8.
Gatzeva-Topalova PZ Warner LR Pardi A Sousa MC 《Structure (London, England : 1993)》2010,18(11):1492-1501
Folding and insertion of β-barrel outer membrane proteins (OMPs) is essential for Gram-negative bacteria. This process is mediated by the multiprotein complex BAM, composed of the essential β-barrel OMP BamA and four lipoproteins (BamBCDE). The periplasmic domain of BamA is key for its function and contains five "polypeptide transport-associated" (POTRA) repeats. Here, we report the crystal structure of the POTRA4-5 tandem, containing the essential for BAM complex formation and cell viability POTRA5. The domain orientation observed in the crystal is validated by solution NMR and SAXS. Using previously determined structures of BamA POTRA1-4, we present a spliced model of the entire BamA periplasmic domain validated by SAXS. Solution scattering shows that conformational flexibility between POTRA2 and 3 gives rise to compact and extended conformations. The length of BamA in its extended conformation suggests that the protein may bridge the inner and outer membranes across the periplasmic space. 相似文献
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Petar Todorov Petia Peneva Daniela Pechlivanova Stela Georgieva Elena Dzhambazova 《Bioorganic & medicinal chemistry letters》2018,28(18):3073-3079
In the present study, some new analogues of VV-hemorphin-5, modified at position 1 and 7 by the non-proteinogenic and/or natural amino acids followed the structures Xxx-Val-Val-Tyr-Pro-Trp-Thr-Gln-NH2 and Val-Val-Tyr-Pro-Trp-Thr-Yyy-NH2, where Xxx is Ile or Aib and Yyy is Lys/Orn/Dap/Dab were synthesized to investigate their potential antinociceptive activities. We report also the redox potentials and the acid/base properties as pKa values of these peptide analogues which were compared toward electrochemical behaviour of tryptophan containing peptides. All analogues showed a short lasting initial antinociceptive effect, however H2 hemorphin analogue is characterized with prolong and strong antinociceptive effect, while the other peptide analogues exerted more variable effects on the visceral nociception depending on the dose or time after the intracerebral injection. 相似文献
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Vockenroth IK Atanasova PP Long JR Jenkins AT Knoll W Köper I 《Biochimica et biophysica acta》2007,1768(5):1114-1120
Tethered bilayer lipid membranes (tBLMs) are robust and flexible model platforms for the investigation of various membrane related processes. They are especially suited to study the incorporation and function of ion channel proteins, where a high background resistance of the membrane is essential. Synthetic M2 peptides, analogues of the transmembrane fragment of the acetylcholine receptor, could be incorporated into two different membrane architectures. The functional reconstitution and the formation of a conducting pore are shown by electrochemical impedance spectroscopy (EIS). The pore is selective for small monovalent cations, while bulky ions cannot pass. This is a significant step towards a novel biosensing approach. We envision a device, where a stable and insulating membrane would be attached to an electronic read-out unit and embedded proteins would serve as actual sensing units. 相似文献