Desenvolvimento de revestimentos fotocatalíticos à base de TiO2 nanométricos pelo método de revestimento por imersão

O artigo descreve o estágio inicial do desenvolvimento de revestimentos fotocatalíticos à base de TiO2 nanométricos utilizando o processo de revestimento por imersão. Os resultados alcançados demonstram que é possível formar revestimentos aderentes, homogêneos e transparentes no espectro vísivil, mantendo os desempenhos fotocatalíticos dos pós precursores

Changes in stable isotope compositions during fasting in phocid seals

This study was supported by NSF grant #0213095 and by FRFC grant #2.4502.07 (F.R.S.-FNRS).Rationale:  The grey seal, Halichoerus grypus (GS), and the northern elephant seal, Mirounga angustirostris (NES), come ashore for reproduction. This period involves intense physiological processes such as lactation in females and a developmental post‐weaning fast in juveniles. Previous studies have shown that δ13C and δ15N values are affected by starvation, but the precise effects of fasting associated to lactation and post‐weaning fast in seals remain poorly understood. Methods:  To examine the effect of lactation and post‐weaning fast on stable isotope ratios in GS and NES, blood and hair were sampled from twenty‐one GS mother‐pup pairs on the Isle of May and on twenty‐two weaned NES pups at Año Nuevo State Reserve during their respective breeding seasons. Milk samples were also collected from GS mothers. Stable isotope measurements were performed with an isotope ratio mass spectrometer coupled to an N‐C elemental analyser. Results:  Changes in stable isotope ratios in blood components during fasting were similar and weak between GS and NES mothers especially in blood cells (GS: Δ15N = 0.05‰, Δ13C = 0.02‰; NES: Δ15N = 0.1‰, Δ13C = 0.1‰). GS showed a 15N discrimination factor between maternal and pup blood cells and milk, but not for 13C. The strongest relationship between the isotopic compositions of the mother and the pup was observed in the blood cells. Conclusion:  Isotopic consequences of lactation, fasting, and growth seem limited in NES and GS, especially in medium‐term integrator tissues of feeding activity such as blood cells. Stable isotope ratios in the blood of pups and mothers are correlated. We observed a subtle mother‐to‐pup fractionation factor. Our results suggest that pup blood cells are mostly relevant for exploring the ecology of female seals.PostprintPeer reviewe

Grapevine rootstocks shape underground bacterial microbiome and networking but not potential functionality

BackgroundThe plant compartments of Vitis vinifera, including the rhizosphere, rhizoplane, root endosphere, phyllosphere and carposphere, provide unique niches that drive specific bacterial microbiome associations. The majority of phyllosphere endophytes originate from the soil and migrate up to the aerial compartments through the root endosphere. Thus, the soil and root endosphere partially define the aerial endosphere in the leaves and berries, contributing to the terroir of the fruit. However, V. vinifera cultivars are invariably grafted onto the rootstocks of other Vitis species and hybrids. It has been hypothesized that the plant species determines the microbiome of the root endosphere and, as a consequence, the aerial endosphere. In this work, we test the first part of this hypothesis. We investigate whether different rootstocks influence the bacteria selected from the surrounding soil, affecting the bacterial diversity and potential functionality of the rhizosphere and root endosphere.MethodsBacterial microbiomes from both the root tissues and the rhizosphere of Barbera cultivars, both ungrafted and grafted on four different rootstocks, cultivated in the same soil from the same vineyard, were characterized by 16S rRNA high-throughput sequencing. To assess the influence of the root genotype on the bacterial communities’ recruitment in the root system, (i) the phylogenetic diversity coupled with the predicted functional profiles and (ii) the co-occurrence bacterial networks were determined. Cultivation-dependent approaches were used to reveal the plant-growth promoting (PGP) potential associated with the grafted and ungrafted root systems.ResultsRichness, diversity and bacterial community networking in the root compartments were significantly influenced by the rootstocks. Complementary to a shared bacterial microbiome, different subsets of soil bacteria, including those endowed with PGP traits, were selected by the root system compartments of different rootstocks. The interaction between the root compartments and the rootstock exerted a unique selective pressure that enhanced niche differentiation, but rootstock-specific bacterial communities were still recruited with conserved PGP traits.ConclusionWhile the rootstock significantly influences the taxonomy, structure and network properties of the bacterial community in grapevine roots, a homeostatic effect on the distribution of the predicted and potential functional PGP traits was found

Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

Contains fulltext : 172380.pdf (publisher's version ) (Open Access

Effects of polychlorobiphenyls, polybromodiphenylethers, organochlorine pesticides and their metabolites on vitamin A status in lactating grey seals

Polychlorobiphenyls (PCBs), polybromodiphenylethers (PBDEs) and organochlorine pesticides (OCPs) such as dichlorodiphenyltrichloroethane (DDT) and hexachlorobenzene (HCB) are considered to be endocrine disruptors in laboratory and wild animals. This study investigated whether these compounds and their hydroxylated metabolites (HO-PCBs and HO-PBDEs) may affect the homeostasis of vitamin A, a dietary hormone, in the blubber and serum of twenty lactating grey seals sampled at early and late lactation on the Isle of May, Scotland. The effect of naturally produced compounds such as the methoxylated (MeO)-PBDEs was also examined. Vitamin A levels in inner blubber (37 ± 9 µg/g wet weight (ww) and 92 ± 32 µg/g ww at early and late lactation, respectively) and serum (408 ± 143 ng/ml and 390 ± 98 ng/ml at early and late lactation, respectively) appeared to be positively related to ΣPCBs, ΣPBDEs and several individual PCB and PBDE congeners in inner blubber and serum. These findings may suggest an enhanced mobilisation of hepatic retinoid stores and a redistribution in the blubber, a storage site for vitamin A in marine mammals, before the onset of lactation. We also reported that serum concentrations of ΣHO-PCBs and 4-OH-CB107 tended to increase circulating vitamin A levels. Although the direction of the relationships may sometimes differ from those reported in the literature, our results are in agreement with previous findings highlighting a disruption of vitamin A homeostasis in the blubber and bloodstream following exposure to environmental pollutants. Previous studies have shown an interesting parallelism between the mobilisation and transfer of vitamin A and those of PCBs in lactating grey seals, contrary to other lipophilic molecules such as vitamin E (Debier et al. 2004; Vanden Berghe et al. 2010). The fact that vitamin A and PCBs appeared to share common mechanisms during this particular physiological state in grey seals (lactation coupled to a total fasting) may also play a role in the different relationships observed between vitamin A and lipophilic pollutants

Supplementary Material: Visible light sensitive mesoporous nanohybrids of lepidocrocite-like ferrititanate coupled to a charge transfer complex: Synthesis, characterization and photocatalytic degradation of NO

Related to the published version: [https://hdl.handle.net/21.15107/rcub_dais_3692]Supporting information for: [http://dx.doi.org/10.1016/j.jphotochem.2018.07.038]Related to the accepted version: [https://hdl.handle.net/21.15107/rcub_dais_4084

Lepidocrocite-like ferrititanate nanosheets and their full exfoliation with quaternary ammonium compounds

Efficient methods for the synthesis of layered structure nanomaterials (nanosheets), their complete exfoliation (delamination) into the layers of atomic thickness and design of organic-inorganic nanohybrids present important stages toward development of improved polymer-based nanocomposites and pillared heterostructures with potential application in purification technologies such as photocatalysis. A rapid and efficient exfoliation process of protonated layered ferrititanates with lepidocrocite-like structure and formation of organic-inorganic nanohybrids is performed starting from the nanosheets composed of only a few host layers and nanometric lateral dimensions using quaternary ammonium compounds. These nanosheets are initially synthesized from a highly abundant precursor through an alkaline hydrothermal route. We demonstrated that dimethyldioctadecylammonium cations strongly interact with the exfoliated single host layers (0.75. nm thick) providing thermal stability (~ 500 °C) to the as-prepared organic-inorganic nanohybrid over the temperature range commonly applied for the processing of thermoplastic nanocomposites. © 2015 Elsevier Ltd

The Influence of Calcination Temperature on Photocatalytic Activity of TiO2-Acetylacetone Charge Transfer Complex towards Degradation of NOx under Visible Light

The improvement of photocatalytic activity of TiO2-based nanomaterials is widely investigated due to the tentative of their industrialization as environmental photocatalysts and their inherently low solar spectrum sensitivity and rapid recombination of charge carriers. Coupling of oxygen-based bidentate diketone to nanocrystalline TiO2 represents a potential alternative for improving the holdbacks. Formation of TiO2-acetylacetone charge transfer complex (CTC) by sol-gel route results in a hybrid semiconductor material with photodegradation activity against toxic NOx gas. In this research, the influence of the chelating agent acetylacetone (ACAC) content on the CTC photocatalytic efficiency under visible light was evaluated. A high content of ACAC in the CTC is not a decisive factor for efficiency of photocatalytic reactions. In fact, the highest efficiency for NOx degradation (close to 100%, during 1 h of visible light exposure) was reported for the material calcined in air at 300 °C with the content of strongly bonded acetylacetone not higher than 3 wt.%. Higher calcination temperature (400 °C) left TiO2 almost completely depleted in ACAC, while at the highest applied temperature (550 °C) a portion of anatase was transformed into rutile and the sample is free of ACAC. The analyses pointed out that superoxide anion radical (O2−) plays an active role in photo-oxidation of NOx. Our findings indicate that this CTC has both high visible light spectral sensitivity and photocatalytic efficiency