390 research outputs found
Improving fire performances of PEAL: More second-life options for recycled Tetra Pak®
The purpose of this work was to evaluate and improve the flammability and combustion behavior of the polyethylene-based material obtained from the recycling of Tetra Pak® (PEAL) to widen its use to applications where these properties are required. Firstly, its thermal stability was investigated with thermogravimetric analysis, resulting in an enhancement in the main degradation step temperature (from 385◦C to 421◦C) due to the presence of the aluminum-flakes. Then, to improve the poor flammability (HB in UL-94 test) and combustion behavior (Fire Performance Index of 0.07) of the raw material, two flame retardant approaches were tested: an intumescent system made of ammonium polyphosphate and pentaerythritol, and magnesium hydroxide. In addition, the effectiveness of polyethylene as a charring agent was evaluated. Characterization was made with UL-94, cone calorimeter, and morphologic analysis. For all the materials tested, the temperature of the main weight loss step increased and the flammability rating improved (V2 for intumescent and V0 for magnesium hydroxide reached). Moreover, fire hazard decreased (Fire Performance Index of 0.15 and 0.55; Flame Retardancy Index of 2.6 and 10.0). Referring to the morphology, full compatibility was found in the PEAL–magnesium hydroxide compound, while PEAL-intumescent appeared as a heterogeneous system
Occurrence and infectivity of vesicular-arbuscular mycorrhizal fungi in north-western Italy vineyards
12 vineyards were surveyed during one year to assess root VA infection and spare population in the soil. 9 fungal species were present; 3 of them were more common and could be reinoculated successfully on grapevine. Other crops, in sites close to the vineyard sampled, often contained a different population of species. More species were present in soils of pH > 7.5.Spores were most abundant in autumn, their number decreasing in spring. Soils with least P and higher pH contained more spores. Root infection was unrelated to spare frequency or soil characters.Infectivity of the soil on grapevine plants, assessed by means of the MPN method, was weil related to the number of spores present in the soil at the same time, if roots were removed. lt is concluded that spore numbers can express the ability of the soil to infect plants, thus showing where artificial inoculation could be potentially more effective
Is it possible to mechanical recycle the materials of the disposable filtering masks?
In a singular period, such as during a pandemic, the use of personal protective masks can become mandatory for all citizens in many places worldwide. The most used device is the disposable mask that, inevitably, generates a substantial waste flow to send to incineration or landfill. The article examines the most diffused type of disposable face mask and identifies the characteristic of the constituent materials through morphological, chemical, physical, and thermal analyses. Based on these investigations, a mechanical recycling protocol with different approaches is proposed. Advantages and disadvantages of the different recycling solutions are discussed with considerations on necessary separation processes and other treatments. The four solutions investigated lead to a recycling index from 78 to 91% of the starting disposable mask weight. The rheological, mechanical, and thermo-mechanical properties of the final materials obtained from the different recycling approaches are compared with each other and with solutions present on the market resulting in materials potentially industrially exploitable
Selection of artichoke plants and analysis of correlation between quantitative traits for fresh consumption
The goals of the present study were to evaluate and select artichoke plants suitable for fresh consumption and to establish correlations between quantitative traits. Clones from 39 accessions were obtained from the germplasm collection of the University of Passo Fundo and evaluated for 17 quantitative and 3 qualitative traits. Data on quantitative traits were subjected to analysis of variance followed by a Tukey test at p<0.05 to compare averages, and correlations were analyzed using the Pearson product moment correlation coefficient. Significant differences were observed for 9 of the 17 quantitative traits analyzed, and 10 of the 39 accessions presented higher values for some of those traits than the remaining tested accessions. Significant correlations were observed between several traits and the capitulum yield, which makes indirect selection easier. For the qualitative traits, nine accessions were selected that presented circular head, violet colored bracts and absence of thorns, which are desirable traits for fresh consumption.Los objetivos del presente estudio fueron evaluar y seleccionar plantas de alcachofa aptas para consumo en fresco y establecer correlaciones entre caracteres cuantitativos. Treinta y nueve accesiones pertenecientes a la colección de germoplasma de la Universidad de Passo Fundo fueron clonadas y luego evaluadas para 17 caracteres cuantitativos y 3 cualitativos. Los datos correspondientes a los caracteres cuantitativos fueron sometidos a análisis de varianza seguido por una prueba comparación de valores medios de Tukey (p<0,05); las correlaciones fueron analizadas utilizando el coeficiente de correlación de Pearson. Se observaron diferencias significativas para 9 de los 17 caracteres cuantitativos analizados y 10 de las 39 accesiones mostraron elevados valores para algunos de esos caracteres. Se observaron valores significativos de correlación entre varios caracteres y el rendimiento, lo que facilita la selección indirecta. Considerando los caracteres cualitativos, se seleccionaron nueve accesiones por presentar capÃtulo esférico, brácteas violetas y ausencia de espinas, las cuales son caracterÃsticas deseables para el consumo en fresco.Fil: Reolon Costa, A.. Universidade de Passo Fundo; BrasilFil: Grando, M. F.. Universidade de Passo Fundo; BrasilFil: Cravero, Vanina Pamela. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Almeida, A.. Universidade de Passo Fundo; Brasi
Recycled PP for 3D Printing: Material and Processing Optimization through Design of Experiment
In this work, blends that were based on first use PP added with talc (PPt) and recycled polypropylene (r-PP) were designed and formulated, aiming at producing filaments that are suitable for 3D printing fused filament fabrication (FFF) processes. A preliminary characterization of PPt/r-PP blends at different weight ratios allowed selecting two systems showing adequate rheological behavior for FFF. The selected blends were melt compounded in a twin-screw extruder, optimizing the processing conditions through a design of experiments approach, involving the use of Taguchi's method. The materials that were prepared with the optimized processing conditions, hence showing the best performance in terms of rheological behavior and thermal characteristics, were then selected for the production of the filament and for the subsequent FFF processing. Finally, the morphology of the filament and the mechanical properties of 3D-printed samples were assessed, demonstrating the achievement of satisfactory results in terms of performances. In general, the obtained results clearly demonstrated that a proper optimization of both material and processing conditions offers the possibility of using recycled PP-based formulations for additive manufacturing processes, hence allowing a remarkable valorization of a low added-value material through its utilization for an innovative and sustainable manufacturing approach
Comparison of J-r test techniques under gaseous hydrogen environment
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New generation anaplastic lymphoma kinase inhibitors
Anaplastic lymphoma kinase (ALK) gene translocations are pro-tumoral driver alterations that encompass 3*7% of non-squamous non-small cell lung cancer (NSCLC) with specific, clinic and histologic features. The therapeutic strategy depends on anti-ALK tyrosine kinase inhibitors (TKIs) of which crizotinib was the first approved for clinical use. Despite its use improved significantly progression-free survival, overall response rate and duration of response of this illness, after a median period of 10.9 months all patients progress due to the development of acquired resistance mutations in the ALK tyrosine kinase domain in approximately one third of patients. Moreover, 60-90% of patients treated with crizotinib has a progression in the central nervous system (CNS) in absence of extracranial worsening of the disease. This is primarily attributed to poor CNS penetration by crizotinib as many pre-clinical and clinical models suggest. For instance, in order to overtake acquired resistance to crizotinib, prolong the control of the disease and manage CNS localizations, several II and III generation TKIs have been developed. Some of them were approved after the failure of crizotinib (ceritinib, alectinib, brigatinib and lorlatinib) and in first line setting (ceritinib, alectinib and brigatinib) while others are still under evaluation for TKI-naive patients such as lorlatinib, ensartinib and entrectinib. In this review we will discuss the most recent results of new TKIs in order to describe a fast growing therapeutic landscape in this setting
Respuesta humoral y consecuencias reproductivas en ovejas desafiadas con Brucella ovis al final de la gestación
La brucelosis ovina por Brucella ovis es una enfermedad de prevalencia alta en Argentina. Para evaluar la patogenicidad de B. ovis y la respuesta serológica durante el último mes de gestación, 6 ovejas se distribuyeron en dos grupos: G1, ovejas preñadas, n = 4 y G2, ovejas no preñadas, n = 2. Tres ovejas del G1 (15 dÃas preparto) y una del G2 fueron inoculadas con B. ovis. Se analizaron muestras de suero mediante diferentes pruebas serológicas. Se realizó aislamiento y PCR a partir de mucus cérvico-vaginal (mcv), placenta y leche. En las muestras de placenta se realizó histopatologÃa. Las hembras del G1 parieron corderos vivos; se detectaron anticuerpos en las ovejas desafiadas del G1 a partir de los 5 dÃas posinoculación. El mcv de las ovejas desafiadas resultó negativo al aislamiento en ambos grupos. Las muestras de leche del G1 fueron positivas por cultivo y PCR a B. ovis. La técnica de PCR resultó positiva en las placentas de las ovejas desafiadas del G1. La histopatologÃa reveló una placentitis necrótica supurativa en una de las ovejas desafiadas. El desafÃo con B. ovis preparto resultó en la invasión de la placenta y de la glándula mamaria, con la consecuente excreción de la bacteria por leche. La infección con B. ovis indujo una respuesta humoral temprana en las ovejas. La colonización de la placenta por B. ovis y la excreción de la bacteria por la leche sugieren un potencial riesgo de infección activa para los corderos y la posibilidad de que estos se comporten como portadores latentes de la infección.Ovine brucellosis by Brucella ovis is a highly prevalent disease in Argentina.
This study aimed to evaluate the pathogenicity of B. ovis and the serological response in ewes during late pregnancy and in their offspring. Six adult ewes were distributed in two groupsG1 (pregnant females, n = 4) and G2 (nonpregnant females, n = 2). Three pregnant ewes at 15 days prepartum and one nonpregnant eve were inoculated with B. ovis. Sera of sheep and their offspring were analyzed by different serological tests.
Samples of cervicovaginal mucus, placenta and milk were studied by bacteriology. A Brucella genus-specific PCR assay was carried out in placenta and milk samples. Placenta samples were hystopathologically processed. G1 females gave birth to live lambs, but one died hours postpartum. Serological techniques employed detected antibodies in serum of inoculated pregnant animal 5 days postchallenge. Sera of female controls G1 and G2 remained negative throughout the study. Cervicovaginal mucus of infected ewes in G1 and G2 yielded negative results to bacteriology, but B. ovis was isolated from milk. The PCR assay was positive for the placenta and milk from inoculated pregnant ewes. Histopathology revealed necrotic suppurative placentitis in one placenta. However, although results demonstrated that B. ovis can invade the placenta and mammary gland, this bacterium did not cause abortion when it was inoculated intravenously at 15 days prepartum. B. ovis infection induced an early humoral response in pregnant ewes, but their lambs remained seronegative, indicating that there was no transfer of antibodies in infancy. Placenta colonization and milk excretion of B. ovis involves a potential source of infection for lambs, which could play a role as latent carriers of infection
YqiC of Salmonella enterica serovar Typhimurium is a membrane fusogenic protein required for mice colonization
<p>Abstract</p> <p>Background</p> <p><it>Salmonella enterica </it>serovar Typhimurium is an intracellular bacterial pathogen which can colonize a variety of hosts, including human, causing syndromes that vary from gastroenteritis and diarrhea to systemic disease.</p> <p>Results</p> <p>In this work we present structural information as well as insights into the <it>in vivo </it>function of YqiC, a 99-residue protein of <it>S</it>. Typhimurium, which belongs to the cluster of the orthologous group 2960 (COG2960). We found that YqiC shares biophysical and biochemical properties with <it>Brucella abortus </it>BMFP, the only previously characterized member of this group, such as a high alpha helix content, a coiled-coil domain involved in trimerization and a membrane fusogenic activity <it>in vitro</it>. In addition, we demonstrated that YqiC localizes at cytoplasmic and membrane subcellular fractions, that a <it>S</it>. Typhimurium <it>yqiC </it>deficient strain had a severe attenuation in virulence in the murine model when inoculated both orally and intraperitoneally, and was impaired to replicate at physiological and high temperatures <it>in vitro</it>, although it was still able to invade and replicate inside epithelial and macrophages cell lines.</p> <p>Conclusion</p> <p>This work firstly demonstrates the importance of a COG2960 member for pathogen-host interaction, and suggests a common function conserved among members of this group.</p
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