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991.
992.
993.
Irene Sánchez Nuria Fernández Ricardo Amils José L Sanz 《International microbiology》2008,11(3):179-184
The aim of the present study was to assess the impact of adding cultures of Thiobacillus denitrificans and Thiomicrospira denitrificans to two upflow anaerobic sludge bed (UASB) reactors: one inoculated with granular sludge and the other filled only with activated carbon (AC). The performances of the bioreactors and the changes in biomass were compared with a non-bioaugmented control UASB reactor inoculated with granular sludge. The reactors inoculated with granular sludge achieved efficiencies close to 90% in nitrate and thiosulfate removal for loading rates as high as 107 mmol-NO3 -/l per day and 68 mmol-S2O3 2-/l per day. Bioaugmentation with Tb. denitrificans and Tm. denitrificans did not enhance the efficiency compared to that achieved with non-bioaugmented granular sludge. The loading rates and efficiencies were 30-40% lower in the AC reactor. In all the reactors tested, Tb. denitrificans became the predominant species. The results strongly suggest that this bacterium was responsible for denitrification and sulfoxidation within the reactors. We additionally observed that granules partially lost their integrity during operation under chemolithoautotrophic conditions, suggesting limitations for long-term operation if bioaugmentation is applied in practice. 相似文献
994.
The complete larval development (four zoeae and one megalopa) of Clibanarius aequabilis and C. erythropus, reared under laboratory conditions, is described and illustrated. The larval stages of the two northeastern Atlantic Clibanarius species cannot be easily differentiated. Their morphological characters are compared with those of other known Clibanarius larvae. The genus Clibanarius is very homogeneous with respect to larval characters. All Clibanarius zoeae display a broad and blunt rostrum, smooth abdominal segments and an antennal scale without a terminal spine. Beyond
the second zoeal stage, the fourth telson process is present as a fused spine, and the uropods are biramous. In the fourth
larval stage all species display a mandibular palp. The Clibanarius megalopa presents weakly developed or no ocular scales, symmetrical chelipeds, apically curved corneous dactylus in the second
and third pereiopods, and 5–11 setae on the posterior margin of the telson. Apart from the number of zoeal stages, Clibanarius species may be separated, beyond the second zoeal stage, by the telson formula and the morphology of the fourth telson process. 相似文献
995.
Relationships between bacterial diversity and environmental variables in a tropical marine environment, Rio de Janeiro 总被引:6,自引:0,他引:6
Vieira RP Gonzalez AM Cardoso AM Oliveira DN Albano RM Clementino MM Martins OB Paranhos R 《Environmental microbiology》2008,10(1):189-199
This study is the first to apply a comparative analysis of environmental chemistry, microbiological parameters and bacterioplankton 16S rRNA clone libraries from different areas of a 50 km transect along a trophic gradient in the tropical Guanabara Bay ecosystem. Higher bacterial diversity was found in the coastal area, whereas lower richness was observed in the more polluted inner bay water. The significance of differences between clone libraries was examined with libshuff statistics. Paired reciprocal comparisons indicated that each of the libraries differs significantly from the others, and this is in agreement with direct interpretation of the phylogenetic tree. Furthermore, correspondence analyses showed that some taxa are related to specific abiotic, trophic and microbiological parameters in Guanabara Bay estuarine system. 相似文献
996.
Tiago Antao Ana Lopes Ricardo J Lopes Albano Beja-Pereira Gordon Luikart 《BMC bioinformatics》2008,9(1):323
Background
Testing for selection is becoming one of the most important steps in the analysis of multilocus population genetics data sets. Existing applications are difficult to use, leaving many non-trivial, error-prone tasks to the user. 相似文献997.
Liang Schweizer Cheryl A Rizzo Thomas E Spires J Suso Platero Qiuyan Wu Tai-An Lin Marco M Gottardis Ricardo M Attar 《BMC cell biology》2008,9(1):4
Background
A crucial event in Prostate Cancer progression is the conversion from a hormone-sensitive to a hormone-refractory disease state. Correlating with this transition, androgen receptor (AR) amplification and mutations are often observed in patients failing hormonal ablation therapies. β-Catenin, an essential component of the canonical Wnt signaling pathway, was shown to be a coactivator of the AR signaling in the presence of androgens. However, it is not yet clear what effect the increased levels of the AR could have on the Wnt signaling pathway in these hormone-refractory prostate cells. 相似文献998.
Background
Vector competence refers to the intrinsic permissiveness of an arthropod vector for infection, replication and transmission of a virus. Notwithstanding studies of Quantitative Trait Loci (QTL) that influence the ability of Aedes aegypti midgut (MG) to become infected with dengue virus (DENV), no study to date has been undertaken to identify genetic markers of vector competence. Furthermore, it is known that mosquito populations differ greatly in their susceptibility to flaviviruses. Differences in vector competence may, at least in part, be due to the presence of specific midgut epithelial receptors and their identification would be a significant step forward in understanding the interaction of the virus with the mosquito. The first interaction of DENV with the insect is through proteins in the apical membrane of the midgut epithelium resulting in binding and receptor-mediated endocytosis of the virus, and this determines cell permissiveness to infection. The susceptibility of mosquitoes to infection may therefore depend on their specific virus receptors. To study this interaction in Ae. aegypti strains that differ in their vector competence for DENV, we investigated the DS3 strain (susceptible to DENV), the IBO-11 strain (refractory to infection) and the membrane escape barrier strain, DMEB, which is infected exclusively in the midgut epithelial cells. 相似文献999.
Chiaradia LD Mascarello A Purificação M Vernal J Cordeiro MN Zenteno ME Villarino A Nunes RJ Yunes RA Terenzi H 《Bioorganic & medicinal chemistry letters》2008,18(23):6227-6230
In the search for lead compounds for new drugs for tuberculosis, the activity of 38 synthetic chalcones were assayed for their potential inhibitory action towards a protein tyrosine phosphatase from Mycobacterium tuberculosis--PtpA. The compounds were obtained by aldolic condensation between aldehydes and acetophenones, under basic conditions. Five compounds presented moderate or good activity. The structure-activity analysis reveals that the predominant factor for the activity is the molecule planarity/hydrophobicity and the nature of the substituents. 相似文献
1000.
Vale N Collins MS Gut J Ferraz R Rosenthal PJ Cushion MT Moreira R Gomes P 《Bioorganic & medicinal chemistry letters》2008,18(2):485-488
A series of primaquine-derived imidazolidin-4-ones were screened for their in vitro activity against Pneumocystis carinii and Plasmodium falciparum W2 strain. Most compounds were active against P. carinii above 10 microg/mL and displayed slight to marked activity. The imidazolidin-4-ones most active against P. carinii were also those most active antiplasmodial agents, in the muM range. One of the tested imidazolidin-4-ones was slightly more active than the parent primaquine and may represent a lead compound for the development of novel anti-P. carinii 8-aminoquinolines with increased stability and resistance to metabolic inactivation. 相似文献