153 research outputs found
Biodiesel as a Plasticizer of a SBR-Based Tire Tread Formulation
The solubility parameter of a series of methyl esters of fatty acids, the components of biodiesel, was calculated using the group incremental method proposed by Van Krevelen. The solubility parameter of biodiesel was compared with that of a series of rubbers like EPDM, butyl rubber, polyisoprene, polybutadiene, SBR (with different content of styrene), and nitrile rubber (with different content of acrylonitrile) showing that biodiesel is an effective solvent of all the above mentioned rubbers with the exclusion of nitrile rubber. Indeed, it was experimentally verified that polyisoprene, polybutadiene and SBR are easily soluble in biodiesel while polystyrene gives a cloudy solution. Considerations on the solubility parameter of the biodiesel and of a series of rubbers have led to the conclusion that biodiesel behaves essentially as an internal lubricant in a diene rubber matrix, the same situation occurs with the common aromatic mineral oil plasticizer known as T-RAE. The experimental evaluation of biodiesel as plasticizer in an SBR-based rubber compound in comparison to an aromatic mineral oil have led to the primary conclusion that biodiesel is reactive with the sulphur curing agent subtracting sulphur to the crosslinking polymer chains and leading to a vulcanizatewith lower moduli, tensile and hardness and higher elongationsin comparison to a reference compound fully plasticized with an aromatic mineral oil. However, biodiesel seems a good low temperature plasticizer because the low elastic modulus observed is desired in a winter tire tread for a good grip on snow and ice. The present work is only an exploratory work, and the tire tread formulation with biodiesel was not optimized
Isotope Exchange in Disulfur Monoxide-Water Charged Complexes: A Mass Spectrometric and Computational Study
A hitherto unknown, isotope-exchange reaction is studied in ionized gaseous mixtures containing disulfur monoxide and water. The kinetics, mechanism, and intermediate of the reaction are investigated by experimental and theoretical methods. The reactivity of the S2O˙+ cation with water is investigated under a wide range of pressures ranging from 10−7 to 10−4 Torr, by FT-ICR, TQ, and high-resolution CAD mass spectrometry. In the high-pressure limit the reaction proves to be a route to strongly bound sulfur-containing species
Metabolomic Profiling, Antioxidant and Antimicrobial Activity of Bidens pilosa
Bidens pilosa L. (fam. Asteraceae) is an annual herb used globally in phytotherapy and each plant material or the whole plant have been declared to be effective. Therefore, the aim of the present study was to conduct metabolomic profiling of different plant materials, including the quali-quantitative composition of phenolic compounds. The intrinsic scavenging/reducing properties and antimicrobial effects of the extracts were assayed against numerous bacterial, Candida and dermatophytes species, whereas docking runs were conducted for tentatively unravelling the mechanism of action underlying antimicrobial effects. Oligosaccharide, disaccharide and fatty acids were present at higher concentrations in root rather than in the other plant parts. Monoglycerides were more abundant in stem than in the other plant parts, whereas peptide and diterpenoid were prominent in leaf and root, respectively. By contrast, amino acids showed very different distribution patterns in the four plant parts. Regarding the phenolic composition, appreciable levels of caftaric acid were found in most of the analyzed methanol extracts, that were also particularly efficacious as antiradical and anti-mycotic agents against C. albicans and dermatophytes. The docking experiments also showed a micromolar affinity of caftaric acid towards the lanosterol 14α-demethylase, deeply involved in fungal metabolism. In conclusion, the present study corroborates the B. pilosa as a phytotherapy remedy against infectious disease
Enhancing routine immunization efforts for older adults and frail individuals: Good practices during the SARS-CoV-2 pandemic in Italy
Infectious diseases pose a significant burden on the general population, particularly older adults who are more susceptible to severe complications. Immunization plays a crucial role in preventing infections and securing a healthier aging, but actual vaccination rates among older adults and frail individuals (OAFs) remains far from recommended targets. This study aims to collect and share good practices implemented in several Italian local health districts during the SARS-CoV-2 pandemic to ease routine immunization for OAFs. A 28-items questionnaire has been developed to collect information on organization aspect of immunization services and local good practices implemented before and during the SARS-CoV-2 pandemic. Twelve Public Health managers representative of 9 Italian Regions were further interviewed between January and March 2021. Despite literature suggests several effective interventions to increase vaccine demand, improve vaccine access, and enhance healthcare providers' performance, our survey highlighted substantial heterogeneity in their implementation at local level. Seven good local practices have been identified and described: mass vaccination centers; vaccination mobile units; drive-through vaccination; co-administration; tailored pathways; cooperation among providers involved in vaccination; digitization. Our survey pointed out valuable strategies for enhancing routine immunization for OAFs. Providers should combine effective interventions adequate to their specific context and share good practices
De la lectura a la creación en la red: el tráiler de lectura
El artÃculo describe y reflexiona sobre las competencias lectoras que tiene que desarrollar un adolescente en un entorno digital. El foco se pone en cómo el entorno digital transforma al lector en un creador de contenidos y en las acciones que se pueden realizar para conseguirlo de manera diversificada, lingüÃstica y culturalmente. La primera parte del estudio desarrolla el concepto de competencia lectora digital: las destrezas que debe desarrollar, los tipos de textos que Internet le propone y las dificultades con las que se encuentra. La segunda parte analiza los resultados de tres estudios de casos en los que la lectura se transforma en creación a través del tráiler de lectura (se trata de concursos realizados en catalán, desde un centro educativo, la biblioteca y la institución pública) y en las acciones de polÃticas públicas que se proponen llevar a cabo para mejorar los resultados
The Swift X-ray flaring afterglow of GRB 050607
The unique capability of the Swift satellite to perform a prompt and
autonomous slew to a newly detected Gamma-Ray Burst (GRB) has yielded the
discovery of interesting new properties of GRB X-ray afterglows, such as the
steep early lightcurve decay and the frequent presence of flares detected up to
a few hours after the GRB trigger. We present observations of GRB 050607, the
fourth case of a GRB discovered by Swift with flares superimposed on the
overall fading X-ray afterglow. The flares of GRB 050607 were not symmetric as
in previously reported cases, showing a very steep rise and a shallower decay,
similar to the Fast Rise, Exponential Decay that are frequently observed in the
gamma-ray prompt emission. The brighter flare had a flux increase by a factor
of approximately 25,peaking for 30 seconds at a count rate of approximately 30
counts s-1, and it presented hints of addition short time scale activity during
the decay phase. There is evidence of spectral evolution during the flares. In
particular, at the onset of the flares the observed emission was harder, with a
gradual softening as each flare decayed. The very short time scale and the
spectral variability during the flaring activity are indicators of possible
extended periods of energy emission by the GRB central engine. The flares were
followed by a phase of shallow decay, during which the forward shock was being
refreshed by a long-lived central engine or by shells of lower Lorentz factors,
and by a steepening after approximately 12 ks to a decay slope considered
typical of X-ray afterglows.Comment: 23 pages, 5 figures, Accepted by the Astrophysical Journa
Current Knowledge on Endocrine Disrupting Chemicals (EDCs) from Animal Biology to Humans, from Pregnancy to Adulthood: Highlights from a National Italian Meeting
Wildlife has often presented and suggested the effects of endocrine disrupting chemicals (EDCs). Animal studies have given us an important opportunity to understand the mechanisms of action of many chemicals on the endocrine system and on neurodevelopment and behaviour, and to evaluate the effects of doses, time and duration of exposure. Although results are sometimes conflicting because of confounding factors, epidemiological studies in humans suggest effects of EDCs on prenatal growth, thyroid function, glucose metabolism and obesity, puberty, fertility, and on carcinogenesis mainly through epigenetic mechanisms. This manuscript reviews the reports of a multidisciplinary national meeting on this topic
West Nile virus transmission. results from the integrated surveillance system in Italy, 2008 to 2015
IIn Italy a national Plan for the surveillance of imported and autochthonous human vector-borne diseases (chikungunya, dengue, Zika virus disease and West Nile virus (WNV) disease) that integrates human and veterinary (animals and vectors) surveillance, is issued and revised annually according with the observed epidemiological changes. Here we describe results of the WNV integrated veterinary and human surveillance systems in Italy from 2008 to 2015. A real time data exchange protocol is in place between the surveillance systems to rapidly identify occurrence of human and animal cases and to define and update the map of affected areas i.e. provinces during the vector activity period from June to October. WNV continues to cause severe illnesses in Italy during every transmission season, albeit cases are sporadic and the epidemiology varies by virus lineage and geographic area. The integration of surveillance activities and a multidisciplinary approach made it possible and have been fundamental in supporting implementation of and/or strengthening preventive measures aimed at reducing the risk of transmission of WNV trough blood, tissues and organ donation and to implementing further measures for vector control
A comparative study of the antimicrobial and antioxidant activities of Inonotus hispidus fruit and their mycelia extracts
Inonotus hispidus (Bull.) P. Karst. has been used as traditional medicine for the treatment of dyspepsia, cancer, and diabetes. Numerous studies have confirmed the antimicrobial, antiviral, antioxidant, anti-inflammatory, immunomodulatory, antiproliferative and cytotoxic biological activities of extracts from this species. The purpose of this study was a comparative analysis of the antioxidant and the antimicrobial activities of methanol extracts from fruit and liquid-cultured mycelia. Four compounds (N-butylbenzenesulfonamide, lauramidopropyl betaine, 3,5-di-tert-butyl-4-hydroxybenzaldehyde, and uplandicine), determined by hybrid HRMS, were found only in mycelia culture extracts. Free radical scavenging, measured by DPPH assay on methanol extracts, showed an activity of about 17.2% and 22.1% of Trolox in fruiting bodies and mycelia, respectively. The I. hispidus methanol extracts from fruit and mycelia culture were found to have varying degrees of antibacterial and antifungal effects against the pathogenic microorganisms tested (minimum inhibitory concentration from 0.17 to 2.56 μg mL−1)
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