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71.
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Single-stranded regions in replicating adenovirus type 5 DNA were isolated and hybridized in solution to the separated strands of adenovirus 2 or 5 DNA. The results showed that the two strands of adenovirus 5 DNA are exposed to almost the same extent during replication, suggesting that displacement synthesis may start from either end of the viral DNA. 相似文献
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Joran Martijn Anders E. Lind Max E. Schön Ian Spiertz Lina Juzokaite Ignas Bunikis Olga V. Pettersson Thijs J. G. Ettema 《Environmental microbiology》2019,21(7):2485-2498
Amplicon sequencing of the 16S rRNA gene is the predominant method to quantify microbial compositions and to discover novel lineages. However, traditional short amplicons often do not contain enough information to confidently resolve their phylogeny. Here we present a cost-effective protocol that amplifies a large part of the rRNA operon and sequences the amplicons with PacBio technology. We tested our method on a mock community and developed a read-curation pipeline that reduces the overall read error rate to 0.18%. Applying our method on four environmental samples, we captured near full-length rRNA operon amplicons from a large diversity of prokaryotes. The method operated at moderately high-throughput (22286–37,850 raw ccs reads) and generated a large amount of putative novel archaeal 23S rRNA gene sequences compared to the archaeal SILVA database. These long amplicons allowed for higher resolution during taxonomic classification by means of long (∼1000 bp) 16S rRNA gene fragments and for substantially more confident phylogenies by means of combined near full-length 16S and 23S rRNA gene sequences, compared to shorter traditional amplicons (250 bp of the 16S rRNA gene). We recommend our method to those who wish to cost-effectively and confidently estimate the phylogenetic diversity of prokaryotes in environmental samples at high throughput. 相似文献
75.
Katarina Tejle Margaretha Lindroth Karl-Eric Magnusson Birgitta Rasmusson 《FEMS microbiology letters》2008,279(1):92-102
The protective immune response against the parasite, including the role of dendritic cells (DC) in the course of infection, plays a fundamental role. This study shows that wild-type (WT) Leishmania promastigotes and specifically the phosphoglycans family of virulence-associated antigens inhibit human monocyte-derived dendritic cells (MoDC) maturation and detachment to distinct surfaces. Immature phagocytosis of Leishmania donovani promastigotes by immature MoDC results in the increased expression of CD11b and CD51, and inhibition of cell detachment to distinct surfaces, which was dependent on the presence of phosphoglycans. These findings demonstrate that phosphoglycans of WT L. donovani might also inhibit human DC migration to lymphoid organs. 相似文献
76.
The aim of the investigation was to study the influence of the rate of water uptake on the uptake of sulphate at supernormal rates of water flow. This was achieved by reducing the size of the root system of 42 days old Ricinus plants. The rate of water flow through the root increased 3 times by reducing the root system to 20 percent. This did not change the retention of sulphate in the roots. The uptake of sulphate was proportional to the size of the root system and thus independent of the rate of water flow while the water uptake (transpiration) was a function of the size of the shoot and the resistance of the root. This was contrary to the conditions at a moderate rate of water flow, when water and sulphate uptake followed each other. The results are discussed in terms of the salt uptake as a series of active and passive processes. 相似文献
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78.
Copper fungicides and mycoinsecticides based on entomopathogenic fungi Beauveria spp. are the most common pesticides used in organic crop production systems. The in vitro effects of the copper fungicides copper oxide, copper hydroxide, copper oxychloride, copper sulphate, dicopper chloride trihydroxide and tribasic copper sulphate were investigated for mycelial growth, sporulation and conidial germination of the ATCC 74040 commercial strain of Beauveria bassiana. Mycelial growth was evaluated on potato dextrose agar plates with 100%, 75%, 50%, 25%, 12.5%, 6.25% and 0% of the recommended application rates of each fungicide at 15 and 25°C. Sporulation and conidial germination were determined at the recommended field doses of each fungicide at 25°C. All copper fungicides had fungistatic or fungicidal effects on B. bassiana that varied according to the dose. Only in two cases, copper oxide at 15°C and copper hydroxide at 25°C, at the lowest concentration of 6.5%, was mycelial growth not statistically significantly inhibited. Inhibition of mycelial growth depended both on the fungicide and its concentration, and partly on temperature. Both sporulation and conidial germination of B. bassiana were significantly inhibited by all fungicides. All fungicides inhibited the sporulation in a similar way (99.8%–100%). With the exception of copper oxychloride (inhibition, 13.6%), the other fungicides showed high detrimental effects on conidial germination (inhibition, 91.7%–100%). The fungus was strongly affected by some fungicides even at the lowest doses. The biological index used for the B. bassiana with copper fungicides ranged from 0.6 (copper sulphate) to 18.1 (copper oxychloride). Therefore, the tested fungicides were classified into the upper half of the highly toxic (T) category and are considered incompatible with the entomopathogenic fungus B. bassiana strain ATCC 74040 under in vivo experimental conditions. These results need to be further verified in vitro under both greenhouse and open-field conditions. 相似文献
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80.
Danijela Krstić Katarina Krinulović Vesna Vasić 《Journal of enzyme inhibition and medicinal chemistry》2013,28(5):469-476
Kinetics and inhibition of Na+/K+-ATPase and Mg2+-ATPase activity from rat synaptic plasma membrane (SPM), by separate and simultaneous exposure to transition (Cu2+, Zn2+, Fe2+ and.Co2+) and heavy metals (Hg2+and Pb2+) ions were studied. All investigated metals produced a larger maximum inhibition of Na+/K+-ATPase than Mg2+-ATPase activity. The free concentrations of the key species (inhibitor, MgATP2 ? , MeATP2 ? ) in the medium assay were calculated and discussed. Simultaneous exposure to the combinations Cu2+/Fe2+ or Hg2+/Pb2+caused additive inhibition, while Cu2+/Zn2+ or Fe2+/Zn2+ inhibited Na+/K+-ATPase activity synergistically (i.e., greater than the sum metal-induced inhibition assayed separately). Simultaneous exposure to Cu2+/Fe2+ or Cu2+/Zn2+ inhibited Mg2+-ATPase activity synergistically, while Hg2+/Pb2+ or Fe2+/Zn2+ induced antagonistic inhibition of this enzyme. Kinetic analysis showed that all investigated metals inhibited Na+/K+-ATPase activity by reducing the maximum velocities (Vmax) rather than the apparent affinity (Km) for substrate MgATP2-, implying the noncompetitive nature of the inhibition. The incomplete inhibition of Mg2+-ATPase activity by Zn2+, Fe2+ and Co2+ as well as kinetic analysis indicated two distinct Mg2+-ATPase subtypes activated in the presence of low and high MgATP2 ? concentration. EDTA, L-cysteine and gluthathione (GSH) prevented metal ion-induced inhibition of Na+/K+-ATPase with various potencies. Furthermore, these ligands also reversed Na+/K+-ATPase activity inhibited by transition metals in a concentration-dependent manner, but a recovery effect by any ligand on Hg2+-induced inhibition was not obtained. 相似文献