Loading of VO2+ and Cu2+ to partially oxidized charcoal fines rejected from Brazilian metallurgical industry

Purpose

Charcoal is utilized in Brazil for the metallurgical industry. Small size pieces, called charcoal fines, are rejected and sometimes are used to produce energy by burning. This charcoal can be used as soil conditioner to improve retention of metal ions in soil. However, changing the charcoal's surface chemistry via oxidation may increase retention of metal ions.

Materials and methods

Two kinds of oxidants were employed, nitric acid and selenium dioxide/hydrogen peroxide. Vanadyl ion (VO²⁺) and copper ion (Cu²⁺) were utilized as probe to study the metal ion complexation by the partially oxidized charcoal obtained. FTIR and EPR spectroscopy were used to characterize the materials.

Results and discussion

Oxidation with nitric acid increased nitrogen content, while oxidation with SeO₂/H₂O₂ elevated carbon content of treated charcoals. Organic free radicals (OFRs) with the unpaired electron in p orbitals of aromatic structures were confirmed by the EPR g-factors that ranged from 2.0038 to 2.0031. The oxidation with selenium dioxide/hydrogen peroxide formed charcoal with largest quantity of OFR. Loading charcoal with VO²⁺ and Cu²⁺ resulted in formation of complexes were oxygen acted as coordination atom. The formed complexes were of axial symmetry. The configurations around the Cu²⁺ ions were: CUNCu²⁺ complex (more stable square planar symmetry) and CFNCu²⁺ complex (less stable distorted tetrahedral configuration). Both complexes had oxygen as coordinating atoms. CFNVO²⁺ and CFSeVO²⁺ complexes presented complexation sites of axial symmetry, C_4v, with oxygen as coordinating atoms.

Conclusions

The oxidative treatment of charcoal with SeO₂/H₂O₂ is more appropriate to produce soil organic conditioner for complexation of metal ions.     

Hard seed breakdown patterns of unprocessed forage legume seed sown into dry soil in summer in southern Australia

The patterns and extent of hard seed breakdown of dormant seeds and pods following burial in the soil in February (summer) varied for up to 19 accessions of 12 species of annual forage legumes. The experiments, at six sites across southern Australia, were designed to identify legumes whose patterns of hard seed breakdown would suit them to agronomic evaluation in a summer sowing research program. For a subset of accessions, sufficient hard seed breakdown was demonstrated between February and April to allow a high proportion of seed to germinate in late autumn—a desirable pattern for summer sowing. Although there was a large G x E interaction, some cultivars of Ornithopus sativus Brot., O. compressus L. and Trifolium spumosum L. had a pattern that was reproducible at all sites. The experiments also identified accessions of Biserrula pelecinus L. and T. glanduliferum Boiss., which had the desirable pattern in regions of south‐eastern Australia, but not Western Australia. A pragmatic approach for selection of forage legume accessions in situ for evaluation within a summer sowing program was demonstrated.     

Control of seed-borne pathogens on legumes by microbial and other alternative seed treatments

Greenhouse trials were carried out in order to test the efficacy of different seed treatments as alternatives to chemicals against Colletotrichum lindemuthianum cause of anthracnose on bean and Ascochyta spp. cause of Ascochyta blights on pea, respectively. Resistance inducers, commercially formulated microorganisms, non-formulated selected strains of different microorganisms (fungi, bacteria and yeasts) and plant extracts were applied as dry or liquid seed treatments on naturally infested seeds. Seedling emergence and disease incidence and/or severity were recorded. Almost all seed treatments turned out to be ineffective in controlling the Ascochyta infections, which is in line with the literature stating that these pathogens are difficult to control. The only alternative treatments that gave some control of Ascochyta spp. were thyme oil and a strain of Clonostachys rosea. The resistance inducers tested successfully controlled infections of bean by C. lindemuthianum. Among the formulated microorganisms, Bacillus subtilis-based formulations provided the best protection from anthracnose. Some strains of Pseudomonas putida, a disease-suppressive, saprophytic strain of Fusarium oxysporum and the mustard powder-based product Tillecur also proved to be effective against bean anthracnose. However, among the resistance inducers as well as among the other groups, certain agents caused a significant reduction of plant emergence. Different alternative seed treatments can therefore be used for the control of C. lindemuthianum on bean, while on pea only thyme oil and a strain of Clonostachys rosea showed some effectiveness against Ascochyta spp.     

Antinociceptive effect and acute toxicity of the essential oil of Hyptis fruticosa in mice

The essential oil of the Hyptis fruticosa leaves was analyzed by GC/MS and evaluated for antinociceptive property as well as acute toxicity in mice. The essential oil, at doses of 100, 200, and 400 mg/kg (s.c.), produced significant inhibition of acetic acid-induced writhing, but did not manifest a significant effect in hot-plate test. There was no acute toxicity at doses up to 5 g/kg. Bicyclogermacrene, 1,8-cineole, alpha-pinene, and beta-caryophyllene were the major compounds detected in the essential oil.     

Antinociceptive effect and acute toxicity of the Hyptis suaveolens leaves aqueous extract on mice

The aqueous extract of Hyptis suaveolens leaves was studied for their antinociceptive property in chemical and thermal models of nociception in mice. Oral administration of the aqueous extract (100, 200, and 400 mg/kg) dose-dependently reduced the number of writhings induced by acetic acid, decreased the licking activity of the early phase in formalin test and increased the reaction time in hot-plate test. The antinociceptive effect was significantly antagonized by naloxone (3 mg/kg; i.p.). Preliminary acute toxicity study showed that no animal death with doses up to 5 g/kg (p.o.).     

Effect of ascorbic acid supplementation on zootechnical performance,haematological parameters and sperm quality of lebranche mullet Mugil liza

The feed provided to breeding fish is one of the main factors influencing the quality of fish gametes. This study was carried out to evaluate the influence of ascorbic acid on growth, haematological parameters and sperm quality of Lebranche mullet males (Mugil liza). Six diets with different levels of ascorbic acid (0; 53; 107; 216; 482 and 708 mg/kg) were tested in triplicate for 75 days. During spermiation (first gonadal maturation), 144 individuals (205.7 ± 11.5 g and 25.7 ± 0.4 cm) were randomly distributed in 18 experimental tanks. Growth parameters were evaluated at the beginning and end of the experiment. Fish blood was collected to analyse glucose, total protein and erythrocyte count (EC) (n = 9). Fish (n = 12) from each treatment were euthanized to determine hepatosomatic index (HSI) and gonadosomatic index (GSI). Semen was collected to evaluate spermatic density, cell membrane integrity and sperm motility. No difference (p > .05) was found on growth parameters, GSI, HSI and total protein. However, EC was lower in fish fed without ascorbic acid (the control group). Ascorbic acid supplementation provided positive effects on sperm characteristics. Fish from treatments with 53 and 107 mg/kg presented the best results for motility time (133.30 ± 4.25 and 135.00 ± 2.77 respectively). Treatments with 107, 216 and 708 mg/kg provided the best results for motility rate (92.0 ± 2.9%, 93.0 ± 5.8% and 93.0 ± 5.8% respectively). Supplementation with 107 and 216 mg/kg provided the best results for plasma membrane integrity (70.12 ± 9.10% and 76.3 ± 3.1% respectively). Lower spermatic density was observed in fish without ascorbic acid supplementation, although no difference was found in sperm density among the treatments with ascorbic acid (p < .05). Considering these results, supplementation of dietary ascorbic acid between 107 and 216 mg/kg optimizes the spermatic quality in males of lebranche mullet.     

Inferred longevity of Amazonian rainforest trees based on a long-term demographic study

We used data from a long-term (14–18 years) demographic study to infer the maximum longevity for populations of 93 relatively abundant tree species in central Amazonia. We also assessed the influence of several life-history features (wood density, growth form, mortality rate, recruitment rate, stem diameter, growth increment, population density) on tree longevity. Data on 3159 individual trees were collected in 24 permanent, 1 ha plots in undisturbed forest arrayed across a large (ca. 1000 km²) study area. For each species, three estimates of longevity were generated (by dividing the stem diameter of the largest tree by the median, upper quartile, and upper decile of observed diameter-growth rates), and the mean of these three values was used as a longevity estimate. Longevity values ranged from 48 years in the pioneer Pourouma bicolor (Cecropiaceae) to 981 years for the canopy tree Pouteria manaosensis (Sapotaceae), with an overall mean of 336±196 years. These growth-based estimates of maximum tree age were concordant with those derived from analyses of mean mortality rates. Tree longevity was positively correlated with wood density, maximum stem diameter, and population density, and negatively correlated with annual mortality, recruitment, and growth rates. On average, pioneer species had much lower longevity than did non-pioneers, whereas among old-growth trees, emergent species had greater longevity than did canopy species. Our results are consistent with radiocarbon-based studies that suggest that Amazonian trees can occasionally exceed 1000 years of age.     

Positive correlation between high levels of ochratoxin A and resveratrol-related compounds in red wines

The natural occurrence of ochratoxin A in red wines has been widely reported by several authors, as well as a that of group of stilbenes including cis- and trans-resveratrols and related glucosylated forms. In the present study 112 samples of retail red wines were collected from northern (17), central (46), and southern (49) Italy and were analyzed for both ochratoxin A and resveratrol-related stilbenes. The mean levels of total resveratrols and total piceids were 3.14 and 5.80 mg/L, respectively, whereas the ochratoxin A mean level was 0.64 microg/L. The Merlot wines showed the highest mean value of total stilbenes, followed by Negroamaro and Negroamaro blend, Aglianico, and Syrah, all with mean levels of >10 mg/L. Ochratoxin A was detected in 70, 59, and 100% of wine samples from northern, central, and southern Italy, with mean levels of 0.12, 0.07, and 1.36 microg/L, respectively. The highest values of ochratoxin A were recorded in Negroamaro- and Primitivo-based wine samples from southern Italy, showing also the highest content of stilbenes. In wine samples from southern Italy, a positive correlation was obtained between levels of ochratoxin A and total stilbenes (r = 0.74) as well as between ochratoxin A and total resveratrols (r = 0.50) and between ochratoxin A and total piceids (r = 0.74). These results suggest that toxic levels of ochratoxin A in red wine may be, at some extent, counterbalanced by the beneficial effects of resveratrol derivatives. Further investigation should be warranted in this regard.     

From field to health: a simple way to increase the nutraceutical content of grape as shown by NO-dependent vascular relaxation

Polyphenolic grapevine components involved in plant resistance against pathogens possess various pharmacological properties that include nitric oxide (NO)-dependent vasodilation and anti-inflammatory and free radical scavenging activities, which may explain the protective effect of moderate red wine consumption against cardiovascular disease. The aim of this work was (a) to verify the possibility that preharvest treatments of grapevine with a plant activator, benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH), could lead to an enriched nutraceutical potential of wine and (b) to characterize the profile of metabolites responsible for pharmacological activity. Plant spraying at the end of veraison, with a water suspension of BTH (0.3 mM), led to increased whole anthocyanin content as confirmed by HPLC comparative analysis. Extracts from berry skins of BTH-treated grapevines caused NO-dependent vasorelaxation, with a concentration-response curve that was significantly shifted to the left of the control non-BTH-treated curve. Moreover, 1:1000 dilutions of berry extracts from BTH-treated plants significantly increased basal production of guanosine 3',5'-cyclic monophosphate (cGMP) in human vascular endothelial cells when compared to the corresponding extracts of untreated plants. These results show that BTH treatment increases anthocyanin content of grape extracts, as well as their ability to induce NO-mediated vasoprotection. No increase of anthocyanin content was observed in the wine extracts from BTH-treated vines. It is concluded that BTH treatment could be exploited to increase the nutraceutical potential of grapes.