Degradation of carbendazim in aqueous solution by different settings of photochemical and electrochemical oxidation processes.

The present study analyzed the performance of photochemical and electrochemical techniques in the degradation and mineralization of the pesticide carbendazim (CBZ). Direct photolysis (DP), heterogeneous photocatalysis (HP), photoelectrocatalysis (PEC), and electrochemical oxidation (EO) were tested, and the influence of UV radiation, current density (j), and supporting electrolyte concentration were evaluated. The results suggest that CBZ is only degraded by DP when UV-C254nm is used. For HP, the CBZ degradation was observed both when UV-A365nm or UV-C254nm were used, which is related to the reactive oxygen species (ROS) formed by the photocatalytic activity (photon-ROS). Neither DP nor HP were able to mineralize CBZ, demonstrating its resistance to photomediated processes. For EO, regardless of the j, there were higher CBZ degradation and mineralization than those observed when using DP and HP. The increase in the supporting electrolyte concentration (Na2SO4) did not affect the levels of degradation and mineralization of CBZ. Concerning the PEC, a CBZ mineralization of 52.2% was accomplished. These findings demonstrate that the EO is the main pathway for CBZ mineralization, suggesting an additional effect of the electro-ROS on the photon-ROS and UV-C254nm. The values of mineralization, kinetics, and half-life show that PEC UV-C254nm with a j of 15 mA cm-2 was the best setting for the degradation and mineralization of CBZ. However, when the values of specific energy consumption were considered for industrial applications, the use of EO with a j of 3 mA cm-2 and 4 g L-1 of Na2SO2 becomes more attractive. The assessment of by-products formed after this best cost-efficient treatment setting revealed the presence of aromatic and aliphatic compounds from CBZ degradation. Acute phytotoxicity results showed that the presence of sodium sulfate can be a representative factor regarding the toxicity of samples treated in electrochemical systems.

Effect of organic compost and inorganic nitrogen fertigation on spinach growth, phytochemical accumulation and antioxidant activity.

The aim of this study was to evaluate the effect of the addition of organic compost in combination with the inorganic nitrogen fertigation on growth, phytochemical accumulation, and antioxidant activity of spinach (Spinacia oleracea L. cv. Manatee). Soil blocked spinach seedlings (six seedlings per block), three blocks per pot (316 plants m-2) were transplanted after 18 days after emergence into to 12 L pots. The treatments were: unfertilized soil, organic compost, organic compost +75 kg of N ha-1, applied as ammonium sulfate; and organic compost +75 kg N ha-1, applied as ammonium nitrate. The addition of organic compost to unfertilized soil increased the fresh yield. The application of inorganic N from the two sources in relation to organic compost treatment increased spinach fresh yield from 2.3 to 4.81 kg m-2 and shoot dry weight from 0.60 to 1,31 g plant-1. Levels of carotenoids also increased with inorganic N addition, producing higher values in plants grown with organic compost + ammonium nitrate (31.14 mg/100 g fresh weight). However, the addition of N led to a decrease in leaf-blade total phenols from 75 to 56 mg gallic acid equivalents/100mg fresh weight. The addition of inorganic N led to a dramatic decrease in leaf-blade ferric reducing antioxidant activity. This effect was higher with ammonium sulfate application. The application of organic compost and inorganic nitrogen had no influence on the petiole's phytochemical accumulation and antioxidant activity.

Sources of food contamination in a closed hydroponic system.

This study investigated potential contamination sources in a commercial, closed hydroponic system. Water, substrate and lettuce (Lactuca sativa) samples were evaluated for microbiological indicator populations, including aerobic plate count (APC), coliform bacteria (CB) and yeast and mould (YM). Listeria spp. detection via cultural enrichment and agglutination was negative for all samples. Peat moss substrate (postharvest) had the highest counts for APC (6·8 log CFU per g), CB (4·5 log MPN per g) and YM (5·1 and 4·8 log CFU per g respectively). Roots embedded in plugs demonstrated counts for all populations nearly as high as the substrate. Among water samples, a seedling water reservoir housing germinated plants yielded the highest count for APC (5·1 log CFU per g) and CB (2·4 log MPN per g) likely due to the large numbers of plugs and their close proximity in the reservoir. Harvested lettuce leaves demonstrated higher APC (4·1 log CFU per g) than preharvest leaves (1·7 log CFU per g) due to the transfer of microbes from the root ball. These data suggest that substrates are a significant potential source of contamination in hydroponic systems and likely facilitate microbial transfer to harvested leaves. There is, therefore, the need to further investigate mitigation of potential contamination events. SIGNIFICANCE AND IMPACT OF THE STUDY: Hydroponic production is known to provide safe, clean produce. This study, however, suggests that the hydroponic substrate (peat moss plug) is a possible source of contamination in the hydroponic system. This finding is important as most harvested hydroponic lettuces are packaged and sold with substrate and root ball intact. This implies a high probability of microbial transfer from the root ball to edible harvested lettuce leaves.

Plant growth, phytochemical accumulation and antioxidant activity of substrate-grown spinach.

Spinach production in soilless cultivation systems, mainly in substrate, transplanted with soil blocks and drip-irrigation is increasing worldwide. However, spinach establishment with soil blocks, with several seedlings per block compared with traditional planting methods, may affect light interception by plant canopy, wetting and salt patterns in root medium and therefore the plant growth and functional value of spinach. The effects of soil block number (plant density) and emitters spacing on plant growth, nitrate, proline and total phenols content and antioxidant activity were evaluated in spinach (Spinacia oleracea L). Five seedlings per soil block were transplanted to Styrofoam boxes filled with the substrate and grown during winter in an unheated greenhouse. Four treatments were carried out with two soil block numbers [8 (160 plants/m2) and 14 (280 plants/m2) soil blocks per Styrofoam box] and two emitter spacing [emitters spaced every 25 and 12.5 cm, respectively, with 4 and 8 emitters per Styrofoam box]. Neither plant density nor emitter spacing had any effect on shoot dry weight. Fresh yield increased as planting density and the number of emitters per Styrofoam box increased. The yield in Styrofoam boxes with 160 plants/m2 and 8 emitters (3.85 kg m-2) was ≈31 % lower than that obtained in treatment with 280 plants/m2 and 8 emitters (5.09 kg m-2). However, the leaf blade of the latter treatment presented a higher content of phenols and proline and greater antioxidant activity (FRAP and DPPH) as well as lower content of nitrate and lesser PDH activity. Decrease of space between emitters reduced the leaf blade nitrate concentration of spinach grown in a greenhouse during the winter. Leaf blade antioxidant activity (FRAP) decreased as planting density increased.

Mini-implants and narrow diameter implants as mandibular overdenture retainers: A systematic review and meta-analysis of clinical and radiographic outcomes.

This study reviews the clinical and radiographic outcomes of Mini-implants (MI) and Narrow Diameter Implants (NDI) as mandibular overdenture (MO) retainers. Six databases were consulted for clinical studies that evaluated implants with diameter ≤3.5 mm. Data on the MI and NDI for survival and success rate and peri-implant bone loss and were collected and submitted to meta-analysis. Thirty-six studies were included, 24 reporting MI performance and 12 describing NDI results. The MI group comprised data from 1 cross-sectional clinical study, 3 retrospective longitudinal (RL) clinical studies, 13 prospective longitudinal (PL) clinical studies and 7 randomised clinical trials (RCT) with follow-up periods ranging from 1 day to 7 years. Eight studies used conventional loading, thirteen used immediate loading, two studies used both loading types, and one study did not report. The NDI group comprised data from 3 RL clinical studies, 6 PL clinical studies and 3 RCT with follow-up ranging from 6 months to 10 years. Ten studies used conventional loading, 1 study used immediate loading, and 1 study did not report. The average survival rates of MI and NDI studies were 98% and 98%, respectively, while the average success rates were 93% and 96%, respectively. The average peri-implant bone loss after 12, 24 and 36 months was 0.89, 1.18 and 1.02 mm for MI and 0.18, 0.12 and -0.32 mm for NDI. Both MI and NDI showed adequate clinical behaviour as overdenture retainers. The NDI showed a better long-term predictability to retain OM with most studies adopting conventional loading.

How does mandibular bone atrophy influence the masticatory function, OHRQoL and satisfaction in overdenture wearers? Clinical results until 1-year post-loading.

This longitudinal clinical study investigated the differences in the masticatory function (MF), satisfaction and oral health-related quality of life (OHRQoL) between atrophic patients (AP) and non-atrophic patients (NAP) before and after rehabilitation with mandibular overdenture (MO). Twenty-six complete denture (CD) wearers were categorised into two groups, according to the mandibular bone atrophy (MBA) degree. MF was evaluated before and after 1, 3, 6 and 12 months of the MO loading via 2 standardised tests: (i) MP, masticatory performance (MP_X50, MPB, ME 5·6, ME 2·8) and (ii) ST, swallowing threshold (time, number of cycles, ST_X50, STB, ME 5·6, ME 2·8). The dental impact on daily living (DIDL) questionnaire measured changes in the satisfaction level and OHRQoL. MP comparisons showed significant difference only for ME 5·6 12 months after MO loading (AP=33·79 ± 23·6; NAP=17·58 ± 20·1). ST presented significant differences before MO loading for: ST_X50 (AP=5·48 ± 0·83; NAP=4·31 ± 1·44), ME 5·6 (AP=53·17 ± 24·71; NAP=29·83 ± 31·45) and ME 2·8 (AP=8·76 ± 6·91; NAP=18·61 ± 10·71). One month after MO loading, NAP performed the ST test 21% faster than AP. After 3 months, significant improvements in STB (AP=4·93 ± 4·82; NAP=2·73 ± 1·27) and ME 2·8 (AP=17·15 ± 10·00; NAP=24·69 ± 7·82) also were observed. DIDL evaluation showed significant differences in the oral comfort domain after 3 months (AP=0·66 ± 0·29; NAP=0·87 ± 0·16) and after 6 months (AP=0·79 ± 0·22; NAP=0·98 ± 0·08), with lower satisfaction levels in the AP. MBA negatively affects the MF mainly the ST. After 6 months, differences between AP and NAP disappeared and ST results were equalised. AP initially has lower satisfaction levels reaching similar levels of satisfaction as NAP after 1 year.

Environmental variations drive polyploid evolution in neotropical Eugenia species (Myrtaceae).

Polyploidy is one of the most important mechanisms of speciation and diversification in plant evolution. Polyploidy results in genetic variation among individuals of the same species and even between populations, and may be responsible for differences in environmental tolerance between populations of the same species. This study determined chromosome numbers of Eugenia L. (Myrtaceae, x = 11) for 26 populations of 14 species by conventional cytogenetic techniques. Nine species (13 populations) were diploid (2n = 2x = 22), but diploid and/or polyploid cytotypes were found in the other five species (13 populations), with 2n = 33, 2n = 44, and 2n = 55. Data on chromosome number/ploidy level for other Eugenia species/populations were collected from the literature and included in this cytogeographic analysis. For each collection point (32 species and 62 populations), environmental variables were recorded using georeferencing techniques through the DIVA-GIS v.7.5 program. Environmental variables such as temperature, altitude, rainfall, solar radiation, soil type, and vegetation were analyzed with the R program, using Mann-Whitney and chi-square tests, principal component analysis, and graphic analyses, such as scatterplots, boxplots, and barplot. Polyploid and diploid populations had different spatial distribution patterns and were found in areas subjected to different environmental conditions. Polyploid individuals were collected from locations with more adverse environmental conditions, usually at higher elevations than the diploid individuals. Polyploidy allows species to occur at locations with varying environmental conditions. As diploidy and polyploidy occur under different environmental conditions, species with cytotypes exhibit wide environmental tolerance.

Psoralen-sensitive mutant pso9-1 of Saccharomyces cerevisiae contains a mutant allele of the DNA damage checkpoint gene MEC3.

Complementation analysis of the pso9-1 yeast mutant strain sensitive to photoactivated mono- and bifunctional psoralens, UV-light 254 nm, and nitrosoguanidine, with pso1 to pso8 mutants, confirmed that it contains a novel pso mutation. Molecular cloning via the reverse genetics complementation approach using a yeast genomic library suggested pso9-1 to be a mutant allele of the DNA damage checkpoint control gene MEC3. Non-complementation of several sensitivity phenotypes in pso9-1/mec3Delta diploids confirmed allelism. The pso9-1 mutant allele contains a -1 frameshift mutation (deletion of one A) at nucleotide position 802 (802delA), resulting in nine different amino acid residues from that point and a premature termination. This mutation affected the binding properties of Pso9-1p, abolishing its interactions with both Rad17p and Ddc1p. Further interaction assays employing mec3 constructions lacking the last 25 and 75 amino acid carboxyl termini were also not able to maintain stable interactions. Moreover, the pso9-1 mutant strain could no longer sense DNA damage since it continued in the cell cycle after 8-MOP + UVA treatment. Taken together, these observations allowed us to propose a model for checkpoint activation generated by photo-induced adducts.

Developments in hydrogenation technology for fine-chemical and pharmaceutical applications.

The continuous innovation in hydrogenation technology is testimony to its growing importance in the manufacture of specialty and fine chemicals. New developments in equipment, process intensification and catalysis represent major themes that have undergone recent advances. Developments in chiral catalysis, methods to support and fix homogeneous catalysts, novel reactor and mixing technology, high-throughput screening, supercritical processing, spectroscopic and electrochemical online process monitoring, monolithic and structured catalysts, and sonochemical activation methods illustrate the scope and breadth of evolving technology applied to hydrogenation.