1,310 research outputs found
Sustainable Recycling of Insoluble Rust Waste for the Synthesis of Iron-Containing Perovskite-Type Catalysts
Insoluble rust waste from the scraping of rusted iron-containing materials represents a cheap, eco-friendly, and available source of iron. LaFeO3 perovskite-type powders were successfully prepared by solution combustion synthesis using rust waste from an electricity transmission tower manufacturer. Solution combustion synthesis enabled introduction of this insoluble iron precursor directly into the final product, bypassing complex extraction procedures. Catalytic activity in the propylene oxidation of the waste-derived LaFeO3 with stoichiometric Fe/La ratio was almost identical to the commercial iron nitrate-derived LaFeO3 , thus demonstrating the viability of this recycling solution. The amount of waste iron precursor was varied and its effect on the powder properties was investigated. A lesser stoichiometric amount of precursor produced a LaFeO3 -La2O3 binary system, whereas a higher stoichiometric amount led to a LaFeO3 -Fe2O3 binary system. Catalytic activity of iron-rich compositions in the propylene oxidation was only slightly lower than the stoichiometric one, whereas iron-poor compositions were much less active. This eco-friendly methodology can be easily extended to other iron perovskites with different chemical compositions and to other iron-containing compounds
Mathematical modeling of the metastatic process
Mathematical modeling in cancer has been growing in popularity and impact
since its inception in 1932. The first theoretical mathematical modeling in
cancer research was focused on understanding tumor growth laws and has grown to
include the competition between healthy and normal tissue, carcinogenesis,
therapy and metastasis. It is the latter topic, metastasis, on which we will
focus this short review, specifically discussing various computational and
mathematical models of different portions of the metastatic process, including:
the emergence of the metastatic phenotype, the timing and size distribution of
metastases, the factors that influence the dormancy of micrometastases and
patterns of spread from a given primary tumor.Comment: 24 pages, 6 figures, Revie
Ultrasonographic measurements of abdominal lymph nodes in growing puppies
The sonographic appearance of the normal abdominal lymph nodes in adult dogs has been well described, but the data in puppies are scarce and of poor quality. The aim of the current study was to evaluate any differences in abdominal lymph node sonographic measurements in puppies of various sizes and to determine whether any differences were correlated with growth and weight gain during the first 10 weeks of life. By an approach based on prospective and serial measurements, length, width and thickness of jejunal, medial iliac and hypogastric nodes were obtained in twenty-one healthy puppies of various sizes, at six (T0), eight (T1) and ten (T2) weeks of age. The relationship between body weight and length, width and thickness of lymph nodes was evaluated using a Pearson correlation analysis. An ANOVA test was used to compare the measurements at different ages. Jejunal and iliac lymph nodes were the largest in large breed dogs. In large-sized puppies only the length of the jejunal lymph nodes correlated positively with width and body weight. Length of medial iliac lymph nodes correlated positively with width and body weight in all three sizes. None of the measurements of hypogastric lymph nodes were related to body weight. In large-sized puppies jejunal and iliac lymph nodes increased in length and width with age; in medium-sized puppies only iliac lymph nodes increased; in small-sized puppies jejunal and iliac lymph nodes significantly decreased in length and thickness. In conclusion, the lymph node sizes in young animals are directly related to body weight and do not decrease with growth during the first 10 weeks of life, except in small-sized puppies
Beneficial effect of cerium excess on in situ grown Sr<sub>0.86</sub>Ce<sub>0.14</sub>FeO<sub>3</sub>–CeO<sub>2</sub> thermocatalysts for the degradation of bisphenol A
Au/CeO2 Photocatalyst for the Selective Oxidation of Aromatic Alcohols in Water under UV, Visible and Solar Irradiation
Au nanoparticles supported on CeO2 have been prepared and investigated as photocatalysts for the photocatalytic selective oxidation of benzyl alcohol and 4-methoxybenzyl alcohol to the correspondent benzaldehydes, in aqueous suspensions and room conditions under UV, visible and
natural solar light irradiation. Au nanoparticles have been supported by impregnation (1 and 3 wt.%) on two types of CeO2 (i.e., a commercial one and a home prepared oxide obtained in the presence of NaOH as precipitation agent). The Au impregnated samples showed strong visible radiation
absorption at 565–570 nm associated to localized surface plasmon resonance (LSPR). The bare CeO2 samples are activated by UV light and resulted virtually inactive under visible irradiation, whereas the presence of Au improved both the conversion of the alcohols and the selectivity of the reaction
towards the aldehyde, giving rise to good results, particularly under visible and natural solar light irradiation. The activity of the materials increased by increasing the Au content
Templating effect of carbon nanoforms on highly cross-linked imidazolium network: Catalytic activity of the resulting hybrids with Pd nanoparticles
Two different carbon nanoforms (CNFs), namely multi-walled carbon nanotubes (MWCNTs) and carbon nanohorns (CNHs), have been chosen as support for the direct polymerization of a bis-vinylimidazolium salt. Transmission electron microscopy analyses revealed a templating effect of the CNFs on the growth of the polymeric network, which perfectly covers their whole surfaces creating a cylindrical or spherical coating for MWCNTs and CNHs, respectively. Subsequently, the CNFs-polyimidazolium have been used as stabilizers for Pd nanoparticles (Pd NPs), and the obtained materials have been characterized by means of analytical and spectroscopic techniques and then employed as easily recoverable and recyclable catalysts for Suzuki and Heck reactions. Quantitative conversions have been obtained in almost all the explored reactions, even employing low loading of catalyst (down to 0.007 mol%). Suzuki reactions were carried out in pure water under aerobic conditions. Both materials showed excellent activity and recyclability for the investigated C-C coupling reactions, with the CNHs-based material resulting slightly more active than the MWCNTs-based one due to a higher superficial exposure of Pd NPs
Third-hand smoke exposure and health hazards in children
Smoking still represents a huge public health problem. Millions of children suffer the detrimental effects of passive smoking. An increasing number of countries have recently issued laws to regulate smoking in public places. Instead, homes remain a site where children are dangerously exposed to environmental tobacco smoke (ETS). The combination of tobacco smoke pollutants which remain in an indoor environment, the so-called 'third-hand smoke' (THS), represent a new concept in the field of tobacco control. THS consists of pollutants that remain on surfaces and in dust after tobacco has been smoked, are re-emitted into the gas-phase, or react with other compounds in the environment to form secondary pollutants. Indoor surfaces can represent a hidden reservoir of THS constituents that could be re-emitted long after the cessation of active smoking. Human exposure to THS pollutants has not yet been thoroughly studied. Infants and children are more prone to the risks related to THS exposure than adults because they typically spend more time indoors and have age-specific behaviours that may expose them to potential health hazards from THS. Further investigations are warranted to study the health effects of THS relevant to different exposure pathways and profiles. It would also be very important to evaluate how THS may affect the lung development through the in utero exposure during the pre-natal life. We aimed at reviewing recent findings published about THS, with special reference to the effects on children's healt
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