430 research outputs found
Biowaste home composting: Experimental process monitoring and quality control
none5noBecause home composting is a prevention option in managing biowaste at local levels, the objective of
the present study was to contribute to the knowledge of the process evolution and compost quality that
can be expected and obtained, respectively, in this decentralized option. In this study, organized as the
research portion of a provincial project on home composting in the territory of Pesaro-Urbino (Central
Italy), four experimental composters were first initiated and temporally monitored. Second, two small
sub-sets of selected provincial composters (directly operated by households involved in the project)
underwent quality control on their compost products at two different temporal steps. The monitored
experimental composters showed overall decreasing profiles versus composting time for moisture,
organic carbon, and C/N, as well as overall increasing profiles for electrical conductivity and total nitrogen,
which represented qualitative indications of progress in the process. Comparative evaluations of the
monitored experimental composters also suggested some interactions in home composting, i.e., high C/N
ratios limiting organic matter decomposition rates and final humification levels; high moisture contents
restricting the internal temperature regime; nearly horizontal phosphorus and potassium evolutions contributing
to limit the rates of increase in electrical conductivity; and prolonged biowaste additions contributing
to limit the rate of decrease in moisture. The measures of parametric data variability in the two
sub-sets of controlled provincial composters showed decreased variability in moisture, organic carbon,
and C/N from the seventh to fifteenth month of home composting, as well as increased variability in electrical
conductivity, total nitrogen, and humification rate, which could be considered compatible with the
respective nature of decreasing and increasing parameters during composting. The modeled parametric
kinetics in the monitored experimental composters, along with the evaluation of the parametric central
tendencies in the sub-sets of controlled provincial composters, all indicate that 12–15 months is a suitable
duration for the appropriate development of home composting in final and simultaneous compliance
with typical reference limits.openFabio TATANO; Giacomo Pagliaro; Paolo Di Giovanni; Enrico Floriani; Filippo ManganiTatano, Fabio; Giacomo, Pagliaro; Paolo Di, Giovanni; Enrico, Floriani; Filippo, Mangan
Iron Binding in the Ferroxidase Site of Human Mitochondrial Ferritin
Ferritins are nanocage proteins that store iron ions in their central cavity as hydrated ferric oxide biominerals. In mammals, further the L (light) and H (heavy) chains constituting cytoplasmic maxi-ferritins, an additional type of ferritin has been identified, the mitochondrial ferritin (MTF). Human MTF (hMTF) is a functional homopolymeric H-like ferritin performing the ferroxidase activity in its ferroxidase site (FS), in which Fe(II) is oxidized to Fe(III) in the presence of dioxygen. To better investigate its ferroxidase properties, here we performed time-lapse X-ray crystallography analysis of hMTF, providing structural evidence of how iron ions interact with hMTF and of their binding to the FS. Transient iron binding sites, populating the pathway along the cage from the iron entry channel to the catalytic center, were also identified. Furthermore, our kinetic data at variable iron loads indicate that the catalytic iron oxidation reaction occurs via a diferric peroxo intermediate followed by the formation of ferric-oxo species, with significant differences with respect to human H-type ferritin
Characterization of the Zinc-binding Site of the Histidine-Proline-rich Glycoprotein Associated with Rabbit Skeletal Muscle AMP Deaminase
The AMP deaminase-associated variant of histidine-proline-rich glycoprotein (HPRG) is isolated from rabbit skeletal muscle by a modification of the protocol previously used for the purification of AMP deaminase. This procedure yields highly pure HPRG suitable for investigation by x-ray absorption spectroscopy of the zinc-binding behavior of the protein. X-ray absorption spectroscopy analysis of a 2:1 zinc-HPRG complex shows that zinc is bound to the protein, most probably in a dinuclear cluster where each Zn(2+) ion is coordinated, on average, by three histidine ligands and one heavier ligand, likely a sulfur from a cysteine. 11 cysteines of HPRG from different species are totally conserved, suggesting that five disulfide bridges are essential for the proper folding of the protein. At least another cysteine is present at different positions in the histidine-proline-rich domain of HPRG in all species, suggesting that this cysteine is the candidate for zinc ligation in the muscle variant of HPRG. The same conclusion is likely to be true for the six histidines used by the protein as zinc ligands. The presence in muscle HPRG of a specific zinc-binding site permits us to envisage the addition of HPRG into the family of metallochaperones. In this view, HPRG may enhance the in vivo stability of metalloenzymes such as AMP deaminase
Grammatical comprehension in italian children with autism spectrum disorder
Language deficits represent one of the most relevant factors that determine the clinical phenotype of children with autism spectrum disorder (ASD). The main aim of the research was to study the grammatical comprehension of children with ASD. A sample of 70 well-diagnosed children (60 boys and 10 girls; aged 4.9–8 years) were prospectively recruited. The results showed that language comprehension is the most impaired language domain in ASD. These findings have important clinical implications, since the persistence of grammatical receptive deficits may have a negative impact on social, adaptive and learning achievements. As for the grammatical profiles, persistent difficulties were found during the school-age years in morphological and syntactic decoding in children with relatively preserved cognitive and expressive language skills. These data and the lack of a statistically significant correlation between the severity of ASD symptoms and language skills are in line with the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition) perspective that considers the socio-communication disorder as a nuclear feature of ASD and the language disorder as a specifier of the diagnosis and not as a secondary symptom anymore. The presence of receptive difficulties in school-age ASD children with relatively preserved non-verbal cognitive abilities provides important hints to establish rehabilitative treatments
Repurposing the trypanosomatidic gsk kinetobox for the inhibition of parasitic pteridine and dihydrofolate reductases
Three open-source anti-kinetoplastid chemical boxes derived from a whole-cell phenotypic screening by GlaxoSmithKline (Tres Cantos Anti-Kinetoplastid Screening, TCAKS) were exploited for the discovery of a novel core structure inspiring new treatments of parasitic diseases targeting the trypansosmatidic pteridine reductase 1 (PTR1) and dihydrofolate reductase (DHFR) enzymes. In total, 592 compounds were tested through medium-throughput screening assays. A subset of 14 compounds successfully inhibited the enzyme activity in the low micromolar range of at least one of the enzymes from both Trypanosoma brucei and Lesihmania major parasites (pan-inhibitors), or from both PTR1 and DHFR-TS of the same parasite (dual inhibitors). Molecular docking studies of the protein–ligand interaction focused on new scaffolds not reproducing the well-known antifolate core clearly explaining the experimental data. TCMDC-143249, classified as a benzenesulfonamide derivative by the QikProp descriptor tool, showed selective inhibition of PTR1 and growth inhibition of the kinetoplastid parasites in the 5 µM range. In our work, we enlarged the biological profile of the GSK Kinetobox and identified new core structures inhibiting selectively PTR1, effective against the kinetoplastid infectious protozoans. In perspective, we foresee the development of selective PTR1 and DHFR inhibitors for studies of drug combinations
Geogenic and atmospheric sources for volatile organic compounds in fumarolic emissions from Mt. Etna and Vulcano Island (Sicily, Italy)
In this paper, fluid source(s) and processes controlling the chemical composition of volatile organic compounds (VOCs) in gas discharges from Mt. Etna and Vulcano Island(Sicily, Italy) were investigated. The main composition of the Etnean and Volcano gas emissions is produced by mixing, to various degrees, of magmatic and hydrothermal components. VOCs are dominated by alkanes, alkenes and aromatics, with minor, though significant, concentrations of O-, S- and Cl(F)-substituted compounds. The main mechanism for the production of alkanes is likely related to pyrolysis of organic-matterbearing sediments that interact with the ascending magmatic fluids. Alkanes are then converted to alkene and aromatic compounds via catalytic reactions (dehydrogenation and dehydroaromatization, respectively). Nevertheless, an abiogenic origin for the light hydrocarbons cannot be ruled out. Oxidative processes of hydrocarbons at relatively high temperatures and oxidizing conditions, typical of these volcanic-hydrothermal fluids, may explain the production of alcohols, esters, aldehydes, as well as O- and S-bearing heterocycles. By comparing the concentrations of hydrochlorofluorocarbons (HCFCs) in the fumarolic discharges with respect to those of background air, it is possible to highlight that they have a geogenic origin likely due to halogenation of both methane and alkenes. Finally, chlorofluorocarbon (CFC) abundances appear to be consistent with background air, although the strong air contamination that affects the Mt. Etna fumaroles may mask a possible geogenic contribution for these compounds. On the other hand, no CFCs were detected in the Vulcano gases, which are characterized by low air contribution. Nevertheless, a geogenic source for these compounds cannot be excluded on the basis of the present data
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