Evaluation of decay and termite resistance of wood treated with copper in combination with boron and N′-N-(1, 8-naphthalyl) hydroxylamine (NHA-Na)

This study evaluated the relative ability of various combinations of copper sulfate with either boric acid or calcium-precipitating agent, N′-N-(1, 8-naphthalyl) hydroxylamine (NHA-Na), to inhibit fungal degradation and attack by Formosan subterranean termites (Coptotermes formosanus Shiraki). Wood specimens were treated with either 1%, 0.5%, or 0.1% concentrations of copper sulfate, boric acid, NHA-Na, copper sulfate + boric acid, or copper sulfate + NHA-Na mixtures. Treated specimens were subjected to laboratory decay-resistance tests by using petri dishes inoculated with the Basidiomycetes fungi Tyromyces palustris and Trametes versicolor for 12 weeks. Treated wood specimens were also subjected to termite-resistance tests under laboratory conditions. Increased efficacy of copper sulfate against the brown-rot fungus T. palustris was observed when either boric acid or NHA-Na was added. The most effective treatments against the fungi tested were NHA-Na only treatments at 1% and 0.5% concentration levels. Boric acid treatments were not able to protect wood against decay after leaching because of excessive leaching of boron. Similar results were obtained in termite-resistance tests in comparison with decay-resistance tests. These results indicate that the efficacy of the treatments in preventing fungal and termite attack is a function of the type of preservative.     

Paternal‐specific S‐allele transmission in sweet cherry (Prunus avium L.): the potential for sexual selection

Homomorphic self‐incompatibility is a well‐studied example of a physiological process that is thought to increase population diversity and reduce the expression of inbreeding depression. Whereas theoretical models predict the presence of a large number of S‐haplotypes with equal frequencies at equilibrium, unequal allele frequencies have been repeatedly reported and attributed to sampling effects, population structure, demographic perturbation, sheltered deleterious mutations or selection pressure on linked genes. However, it is unclear to what extent unequal segregations are the results of gametophytic or sexual selection. Although these two forces are difficult to disentangle, testing S‐alleles in the offspring of controlled crosses provides an opportunity to separate these two phenomena. In this work, segregation and transmission of S‐alleles have been characterized in progenies of mixed donors and fully compatible pollinations under field conditions in Prunus avium. Seed set patterns and pollen performance have also been characterized. The results reveal paternal‐specific distorted transmission of S‐alleles in most of the crosses. Interestingly, S‐allele segregation within any given paternal or maternal S‐locus was random. Observations on pollen germination, pollen tube growth rate, pollen tube cohort size, seed set dynamics and transmission patterns strongly suggest post‐pollination, prezygotic sexual selection, with male–male competition as the most likely mechanism. According to these results, post‐pollination sexual selection takes precedence over frequency‐dependent selection in explaining unequal S‐haplotype frequencies.     

Antioxidant and antimicrobial actions of the clubmoss <Emphasis Type="Italic">Lycopodium clavatum</Emphasis> L.

Purpose of the present study was to evaluate antioxidant, antibacterial, antifungal, and antiviral activities of the petroleum ether, chloroform, ethyl acetate and methanol extracts as well as the alkaloid fraction of Lycopodium clavatum L. (LC) from Lycopodiaceae growing in Turkey. Antioxidant activity of the LC extracts was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging method at 0.2 mg/ml using microplate-reader assay. Antiviral assessment of LC extracts was evaluated towards the DNA virus Herpes simplex (HSV) and the RNA virus Parainfluenza (PI-3) using Madin-Darby Bovine Kidney (MDBK) and Vero cell lines. Antibacterial and antifungal activities of the extracts were tested against standard and isolated strains of the following bacteria; Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Acinobacter baumannii, Klebsiella pneumoniae, Staphylococcus aureus, Bacillus subtilis as well as the fungi; Candida albicans and C. parapsilosis. All of the extracts possessed noteworthy activity against ATCC strain of S. aureus (4 μg/ml), while the LC extracts showed reasonable antifungal effect. On the other hand, we found that only the chloroform extract was active against HSV (16–8 μg/ml), while petroleum ether and alkaloid extracts inhibited potently PI-3 (16–4 μg/ml and 32–4 μg/ml, respectively). However, all of the extracts had insignificant antiradical effect on DPPH. In addition, we also analyzed the content of the alkaloid fraction of the plant by capillary gas chromatography-mass spectrometry (GC-MS) and identified lycopodine as the major alkaloid.     

Some observations on the effect of Daflon (micronized purified flavonoid fraction of Rutaceae aurantiae) in bancroftian filarial lymphoedema

BACKGROUND: Morbidity management is a core component of the global programme for the elimination of lymphatic filariasis. In a double-blind clinical trial, the tolerability and efficacy of Daflon (500 mg) + DEC (25 mg) or DEC (25 mg) alone, twice daily for 90 days, was studied in 26 patients with bancroftian filarial lymphoedema. RESULTS: None of the patients in either drug group reported any adverse reaction throughout the treatment period (90 days). Haematological and biochemical parameters were within normal limits and there was no significant difference between the pre-treatment (day 0) and post-treatment (day 90) values. The group receiving Daflon showed significant reduction in oedema volume from day 90 (140.6 PlusMinus; 18.8 ml) to day 360 (71.8 PlusMinus; 20.7 ml) compared to the pre-treatment (day 0, 198.4 PlusMinus; 16.5 ml) value. This accounted for a 63.8% reduction in oedema volume by day 360 (considering the pre-treatment (day 0) as 100%). In the DEC group, the changes in oedema volume (between day 1 and day 360) were not significant when compared to the pre-treatment (day 0) value. The percentage reduction at day 360 was only 9%, which was not significant (P > 0.05). CONCLUSION: This study has shown that Daflon (500 mg, twice a day for 90 days) is both safe and efficacious in reducing oedema volume in bancroftian filarial lymphoedema. Further clinical trials are essential for strengthening the evidence base on the role of this drug in the morbidity management of lymphatic filariasis.     

Direct intracardiac injection of umbilical cord-derived stromal cells and umbilical cord blood-derived endothelial cells for the treatment of ischemic cardiomyopathy

The development of new therapeutic strategies is necessary to reduce the worldwide social and economic impact of cardiovascular disease, which produces high rates of morbidity and mortality. A therapeutic option that has emerged in the last decade is cell therapy. The aim of this study was to compare the effect of transplanting human umbilical cord-derived stromal cells (UCSCs), human umbilical cord blood-derived endothelial cells (UCBECs) or a combination of these two cell types for the treatment of ischemic cardiomyopathy (IC) in a Wistar rat model. IC was induced by left coronary artery ligation, and baseline echocardiography was performed seven days later. Animals with a left ventricular ejection fraction (LVEF) of ≤40% were selected for the study. On the ninth day after IC was induced, the animals were randomized into the following experimental groups: UCSCs, UCBECs, UCSCs plus UCBECs, or vehicle (control). Thirty days after treatment, an echocardiographic analysis was performed, followed by euthanasia. The animals in all of the cell therapy groups, regardless of the cell type transplanted, had less collagen deposition in their heart tissue and demonstrated a significant improvement in myocardial function after IC. Furthermore, there was a trend of increasing numbers of blood vessels in the infarcted area. The median value of LVEF increased by 7.19% to 11.77%, whereas the control group decreased by 0.24%. These results suggest that UCSCs and UCBECs are promising cells for cellular cardiomyoplasty and can be an effective therapy for improving cardiac function following IC.     

Effect of Nitric Oxide on Anammox Bacteria

The effects of nitrogen oxides on anammox bacteria are not well known. Therefore, anammox bacteria were exposed to 3,500 ppm nitric oxide (NO) in the gas phase. The anammox bacteria were not inhibited by the high NO concentration but rather used it to oxidize additional ammonium to dinitrogen gas under conditions relevant to wastewater treatment.Nitric oxide (NO) has several different roles in bacteria, fungi, and mammals (24). In nitrogen cycle bacteria, it acts as an intermediate and cell communication/signal transduction molecule. On the other hand, NO is a highly reactive and toxic compound that contributes to ozone depletion and air pollution (5). Due to its reactive nature, many bacteria employ an arsenal of proteins (those encoded by norVW, as well as bacterial globins, heme proteins, etc.) that are used to detoxify NO to the less-reactive and more-stable nitrous oxide (N₂O) (24). Still, N₂O is a very effective greenhouse gas and an unfavorable constituent in the off-gases from nitrification/denitrification nitrogen removal systems (4). The presence of gene(s) encoding cytochrome cd₁ nitrite reductase (EMBL accession no. {"type":"entrez-protein","attrs":{"text":"CAJ74898","term_id":"91201838","term_text":"CAJ74898"}}CAJ74898), flavorubredoxin NorVW (accession no. {"type":"entrez-protein","attrs":{"text":"CAJ73918","term_id":"91200863","term_text":"CAJ73918"}}CAJ73918 and {"type":"entrez-protein","attrs":{"text":"CAJ73688","term_id":"91200638","term_text":"CAJ73688"}}CAJ73688), and bacterial hemoglobin (accession no. {"type":"entrez-protein","attrs":{"text":"CAJ72702","term_id":"91203063","term_text":"CAJ72702"}}CAJ72702) in the genome of Kuenenia stuttgartiensis led to the proposal that NO also plays this dual role (metabolic versus toxic) in anammox bacteria (Fig. ​(Fig.1)1) (10, 20). This has ramifications for both application and metabolism of anammox bacteria. The source of NO in an anammox reactor could be the activity of other community members (ammonium-oxidizing or denitrifying bacteria) or high concentrations of nitrite in the influent wastewater stream. Full-scale anammox reactors typically contain a significant population of ammonium-oxidizing bacteria (AOB). In the single nitritation-anammox reactors, these carry out the conversion of 50% of the ammonium in the wastewater to nitrite (6). It has been shown that AOB may produce significant amounts of NO (2, 7), and recently it was reported that NO and N₂O could be emitted from these reactors up to 0.005 and 1.2% of the total nitrogen load to the reactor, respectively (6, 23). NO may inhibit the anammox bacteria and could also be further reduced to N₂O in these reactors (6, 23). It is presently unknown whether anammox bacteria contribute to the NO or N₂O emissions, although it has been suggested previously that anammox bacteria do not produce N₂O under physiologically relevant conditions (10). Nevertheless, if conversion of NO could be coupled to anaerobic ammonium oxidation, the toxic air pollutant NO would facilitate further removal of ammonium in full-scale anammox bioreactors. In the present study, we investigated the effect of very high NO fluxes on anammox bacteria.Open in a separate windowFIG. 1.The hypothetical anammox pathway with possible routes of NO removal. Solid black arrows: anammox pathway, including nitrite oxidation to nitrate; gray arrow, possible detoxification pathway to N₂O (not observed in the bioreactor); dashed gray arrow, NO oxidation to nitrite/nitrate (not possible under anoxic conditions).NO has been described many times as a potent inhibitor of nitrogen cycle bacteria; aerobic ammonium oxidizers, nitrite oxidizers, and denitrifiers were all inhibited by concentrations as low as a few micromolar units (1, 18, 24). In a previous study, it was suggested that “Candidatus Brocadia anammoxidans” could tolerate up to 600 ppm NO (approximately 1 mg NO·day⁻¹ NO load) (16). In the reported experiments, without direct measurement of nitrous oxide (N₂O) in the effluent gas stream, it was postulated that NO was reduced to N₂O (16). In the present study, we used a carefully monitored sequencing batch reactor (SBR) to further our understanding of the effect and fate of NO in a laboratory-scale anammox reactor under conditions which are relevant in wastewater treatment plants.An SBR (working volume, 3.5 liters) consisting of approximately 80% of the anammox bacterium “Candidatus Brocadia fulgida” and no detectable aerobic ammonium oxidizers (determined by fluorescence in situ hybridization (FISH) as described previously [15]) was used in the present study. Before the first introduction of NO into the reactor, the influent (synthetic wastewater) (21) was supplied to the reactor at a flow rate of 1.4 ml·min⁻¹ with nitrite and ammonium concentrations (assayed as previously described [9]) at 45 and 39 mM, respectively (corresponding to a total of 2,370 mg N·day⁻¹). All nitrite was consumed in the reactor, while 2 mM ammonium was still present in the effluent. For every 1 mol of ammonium, 1.22 mol of nitrite was consumed, similar to the previously determined anammox stoichiometry (19). NO was first introduced at a concentration of 400 to 600 ppm in the gas phase at a flow rate of 10 ml/min (CLD 700EL chemiluminescence NOx analyzer, detection limit of 0.1 ppm NO, with 15 ml/min Ar/CO₂ as the dilution gas [a load of 25 to 28 mg NO·day⁻¹]; EcoPhysics, Michigan). During this period, 45% (±6%) of the supplied NO was removed from the system. Initially, there was no detectable change in the ammonium and nitrite removal efficiencies and no detectable nitrous oxide (N₂O) in the flue gas (analyzed with an Agilent 6890 gas chromatograph). It is most likely that NO was converted to N₂, but the increase in the N₂ concentrations in the off-gas was below the detection limit (1,000 ppm).At day 49, the influent NO concentration was increased to 3,500 ppm (640 mg NO·day⁻¹ load). Simultaneously, the stirring speed of the reactor was increased from 200 to 600 rpm to enable better mass transfer to the flocculent anammox biomass. The increase in the stirring speed did not result in any disturbance in the floc size and settling ability of the biomass but did lead to a much higher level of NO removal (128 mg NO·day⁻¹) by the anammox bacteria. The converted NO could theoretically be converted to N₂O via detoxification enzymes or coupled to ammonium oxidation (Fig. ​(Fig.1).1). Surprisingly, there was no change in the nitrite removal capacity of the bioreactor, suggesting that NO was not a substrate preferred over nitrite. Nitrate concentrations (assayed according to the method in reference 9) were stable around 7.2 mM (±0.7 mM). Theoretically, as anammox bacteria reduce NO, they could oxidize a larger proportion of nitrite to nitrate (Fig. ​(Fig.1)1) to increase their capacity for CO₂ fixation; however, such an increase in nitrate production was not observed (or could not be discriminated by the method used [sensitivity, 100 μM]). During this phase of the experiment, the effluent ammonium concentration gradually decreased to below the detection limit (Fig. ​(Fig.2).2). There was only a minimal N₂O (0.6 ppm) emission from the system, and the total N₂ production increased from 3,060 to 3,680 mg N₂·day⁻¹. This indicated that NO reduction was coupled to the catabolism of the anammox bacteria rather than being detoxified by anammox or other community members. To the best of our knowledge, this was the first time that such a high load of NO was not found to be toxic to the nitrogen cycle bacteria. In a previous study, an NO load of 1 mg NO·day⁻¹ was reported to be toxic to anammox bacteria, most probably due to the fact that the experiments were conducted with biomass that had a 100-fold lower cell density and 10-fold lower activity compared to the current enrichment cultures. Furthermore, the NO conversion in the current experiments was stoichiometrically coupled to ammonium oxidation and not converted to N₂O, indicating that the previously reported N₂O emissions from full-scale anammox bioreactors originated not with the anammox bacteria but rather with other community members as hypothesized previously (8).Open in a separate windowFIG. 2.Ammonium concentration in the effluent of the anammox bioreactor. Dashed lines indicate the trend of effluent ammonium concentration during different phases of the reactor operation. Black arrows indicate the manipulations to influent NO stream, and the gray arrow points to an increase in the influent ammonium concentration. d, day.To determine if there could be more NO-dependent ammonium removal, the influent ammonium concentration was first increased to 41 mM (day 80) and then to 43 mM (day 81). This resulted in a slow but gradual increase in the effluent ammonium concentration, and additional ammonium did not appear to be completely converted, most probably due to NO mass transfer limitations. As a result of the higher level of ammonium removal, the observed anammox stoichiometry in the reactor decreased from 1.22 to 0.91 (nitrite/ammonium). Between days 95 and 131, the NO supply to the reactor was turned off, which resulted in an average ammonium concentration of 3.3 mM (±0.9 mM) in the effluent. Following this period, on day 132, the NO load on the reactor was increased back to 640 mg NO·day⁻¹ (Fig. ​(Fig.2).2). As a result, the effluent ammonium concentration gradually decreased again to an average of 1.5 mM (±0.36 mM). The highest level of NO removal achieved in this period was 371 mg NO·day⁻¹. When the NO supply was turned off on day 165, ammonium concentrations increased back to 3.5 mM (±0.71 mM).During the course of the experiment, the biodiversity of the reactor was monitored using FISH and 16S rRNA gene sequence analysis as described previously (15) with probes specific to eubacteria (3), Planctomycetes (13), anammox bacteria (15), “Ca. Brocadia fulgida” (11), and a variety of aerobic ammonium-oxidizing bacteria (12, 22). Before the experiments started and throughout the cultivation of the anammox bacteria with NO, the only detectable anammox species (with FISH and 16S rRNA gene sequence analysis) was “Candidatus Brocadia fulgida.”In the present study, we showed that 2 mM ammonium (4.5% of the influent concentration) could be removed by anammox bacteria via direct coupling to NO reduction. These observations support the proposal of NO as an intermediate of the anammox reaction and have two consequences for application of the anammox process for nitrogen removal. First, we obtained strong indications that previously reported N₂O emissions (6, 8) from full-scale anammox reactors were not generated by anammox bacteria. In our experiments, even under a very high load of NO, there was hardly any detectable N₂O in the effluent gas stream. The competition for nitrogen oxides by denitrifying and anammox bacteria needs further study but may ultimately be used to design operational conditions that would reduce or even prevent NO and N₂O emissions from full-scale nitritation-anammox reactors. Second, by implementing the results of this study, in the future the anammox process could be designed to remove NO from flue gases. Since NO is mostly emitted together with O₂, this could be achieved by the combination of anammox and aerobic ammonium-oxidizing bacteria, for example, with CANON (completely autotrophic nitrogen removal over nitrite)- or OLAND (oxygen-limited autotrophic nitrification-denitrification)-type reactor systems (14, 17).     

Response of anaerobic ammonium-oxidizing bacteria to hydroxylamine

Anaerobic ammonium oxidation is a recent addition to the microbial nitrogen cycle, and its metabolic pathway, including the production and conversion of its intermediate hydrazine, is not well understood. Therefore, the effect of hydroxylamine addition on the hydrazine metabolism of anaerobic ammonium-oxidizing (anammox) bacteria was studied both experimentally and by mathematical modeling. It was observed that hydroxylamine was disproportionated biologically in the absence of nitrite into dinitrogen gas and ammonium. Little hydrazine accumulated during this process; however, rapid hydrazine production was observed when nearly all hydroxylamine was consumed. A mechanistic model is proposed in which hydrazine is suggested to be continuously produced from ammonium and hydroxylamine (possibly via nitric oxide) and subsequently oxidized to N(2). The electron acceptor for hydrazine oxidation is hydroxylamine, which is reduced to ammonium. A decrease in the hydroxylamine reduction rate, therefore, leads to a decrease in the hydrazine oxidation rate, resulting in the observed hydrazine accumulation. The proposed mechanism was verified by a mathematical model which could explain and predict most of the experimental data.     

A microdiversity study of anammox bacteria reveals a novel Candidatus Scalindua phylotype in marine oxygen minimum zones

The anaerobic oxidation of ammonium (anammox) contributes significantly to the global loss of fixed nitrogen and is carried out by a deep branching monophyletic group of bacteria within the phylum Planctomycetes. Various studies have implicated anammox to be the most important process responsible for the nitrogen loss in the marine oxygen minimum zones (OMZs) with a low diversity of marine anammox bacteria. This comprehensive study investigated the anammox bacteria in the suboxic zone of the Black Sea and in three major OMZs (off Namibia, Peru and in the Arabian Sea). The diversity and population composition of anammox bacteria were investigated by both, the 16S rRNA gene sequences and the 16S-23S rRNA internal transcribed spacer (ITS). Our results showed that the anammox bacterial sequences of the investigated samples were all closely related to the Candidatus Scalindua genus. However, a greater microdiversity of marine anammox bacteria than previously assumed was observed. Both phylogenetic markers supported the classification of all sequences in two distinct anammox bacterial phylotypes: Candidatus Scalindua clades 1 and 2. Scalindua 1 could be further divided into four distinct clusters, all comprised of sequences from either the Namibian or the Peruvian OMZ. Scalindua 2 consisted of sequences from the Arabian Sea and the Peruvian OMZ and included one previously published 16S rRNA gene sequence from Lake Tanganyika and one from South China Sea sediment (97.9-99.4% sequence identity). This cluster showed only 相似文献   

Effects of brassinosteroids on barley root growth,antioxidant system and cell division

Homobrassinolide (HBR), which is one of the most biologically active forms of Brassinosteroids (BRs), was used to examine the potential effects of hormone on root germination, antioxidant system enzymes and cell division of barley (Hordeum vulgare L.). Seeds were germinated between filter papers in 0.1, 0.5 and 1.0 μM HBR-supplemented distilled water for 48 h at dark with their controls. HBR application increased especially the primary root growth significantly with increasing concentrations when compared with the control materials and reached two fold increase in 1.0 μM HBR treated material. Treated and untreated control group roots were fixed in 1:3 aceto-alcohol and aceto-orcein preparations were made. Roots treated with HBR showed more mitotic activity, mitotic abnormalities and significant enlargements at the root tips when compared with control material. HBR application decreased total soluble protein content, superoxide dismutase (EC 1.15.1.1), catalase (EC 1.11.1.6) and peroxidase (EC 1.11.1.11) activities significantly at 1.0 μM HBR concentration. Data presented here is one of the first detailed analyses of HBR effect on barley root development.     

Do the unique properties of nanometals affect leachability or efficacy against fungi and termites?

Nanotechnology has the potential to affect the field of wood preservation through the creation of new and unique metal biocides with improved properties. This study evaluated leachability and efficacy of southern yellow pine wood treated with copper, zinc, or boron nanoparticles against mould fungi, decay fungi, and Eastern subterranean termites. Results showed that nanocopper with and without surfactant, nanozinc, and nanozinc plus silver with surfactant resisted leaching compared with metal oxide controls. Nearly all nanoboron and boric acid was released from the treated wood specimens during leaching. Mould fungi were moderately inhibited by nanozinc oxide with surfactant, but the other nanometal preparations did not significantly inhibit mould fungi. Mass loss from Gloeophyllum trabeum was significantly inhibited by all copper preparations, while Antrodia sp. was not inhibited by nanometal treatments. Nanometals imparted high resistance in southern yellow pine to the white-rot fungus, Trametes versicolor. Unleached specimens treated with nanoboron or nanozinc plus surfactant caused 100% and 31% mortality, respectively. All specimens treated with nanozinc or nanozinc plus silver inhibited termite feeding, but the copper treatments were less effective against termites. Nanozinc possessed the most favorable properties: leach resistance, termite mortality, and inhibition of termite feeding and decay by the white-rot fungus.