186 research outputs found
Experimental investigation on the use of waste elastomeric polymers for bitumen modification
The study described in this paper focused on the possible use of waste products coming from the production of styrene-butadiene rubber (SBR) and polybutadiene rubber (PBR), as bitumen modifiers. Modified binders containing these products were prepared in the laboratory with different polymer dosages and were thereafter subjected to the evaluation of empirical and rheological properties. For comparative purposes, the study also considered SBR and PBR products of premium quality. Ageing effects were also taken into account by means of proper laboratory simulations. Obtained results indicated that the two types of polymer (SBR and PBR) have completely different effects on the rheology and expected performance of the resulting modified binders. In particular, while the two polymers showed similar effects in terms of resistance to permanent deformation, the SBR products proved to be superior from the viewpoint of fatigue resistance. However, only minor differences were found when comparing the effects produced by premium quality and waste polymers. As a result of the experimental findings, it was concluded that the use of waste SBR polymers can be an attractive solution for the production of affordable modified binders
Design and Construction of a Full-Scale Test Section with Asphalt Rubber Gap-Graded Wearing Course Mixture
A full-scale test section with asphalt rubber gap-graded wearing course mixture was designed and constructed on a major infrastructure as part of a regional research and implementation project. Standard and performance-related laboratory tests were carried out in order to select constituent materials, define the job-mix formula and monitor construction operations. Gaseous emissions of the bituminous mixture sampled during laying were analyzed to assess the potential risks to which labourers are exposed during paving. Environmental compatibility was also evaluated by performing laboratory leaching tests. Based on the results obtained in the investigation, technical guidelines were validated and enhanced
CHARACTERIZATION OF CRUMB RUBBER FROM END-OF-LIFE TYRES FOR PAVING APPLICATIONS
Crumb rubber (CR) derived from grinding of end-of-life tyres (ELTs) may be successfully used as a bitumen modifier or as a supplementary component in the production of bituminous mixtures employed for the construction and maintenance of road pavements. However, CRs deriving from different sources and processes yield effects on performance under traffic loading and on gaseous emissions produced during laying on site which may change considerably depending upon their physical and chemical properties. In order to quantitatively assess the possible variability of CR characteristics, samples were taken from 9 Italian and 2 foreign ELT processing plants. Investigation activities included field surveys, during which plants were examined in detail, and laboratory tests, which focused on physical and chemical characterization of CR. Based on the analysis of available technical information and experimental data, it was possible to find relationships between the peculiar characteristics of treatment cycles and corresponding CR properties
Design and Construction of a Full-Scale Test Section with Asphalt Rubber Gap-Graded Wearing Course Mixture
A full-scale test section with asphalt rubber gap-graded wearing course mixture was designed and constructed on a major infrastructure as part of a regional research and implementation project. Standard and performance-related laboratory tests were carried out in order to select constituent materials, define the job-mix formula and monitor construction operations. Gaseous emissions of the bituminous mixture sampled during laying were analyzed to assess the potential risks to which labourers are exposed during paving. Environmental compatibility was also evaluated by performing laboratory leaching tests. Based on the results obtained in the investigation, technical guidelines were validated and enhanced
Characterization of crumb rubber from end-of-life tyres for paving applications
Crumb rubber (CR) derived from grinding of end-of-life tyres (ELTs) may be successfully used as a bitumen modifier or as a supplementary component in the production of bituminous mixtures employed for the construction and maintenance of road pavements. However, CRs deriving from different sources and processes yield effects on performance under traffic loading and on gaseous emissions produced during laying on site which may change considerably depending upon their physical and chemical properties. In order to quantitatively assess the possible variability of CR characteristics, a wide experimental program was set out in order to analyze samples taken from 14 Italian and 2 foreign ELT processing plants. Activities included field surveys, during which plants were examined in detail, and laboratory investigations, which focused on physical and chemical characterization of CR. Based on the analysis of available technical information and experimental data, it was possible to find relationships between the peculiar characteristics of treatment cycles and corresponding CR properties
Urinary gas chromatography mass spectrometry metabolomics in asphyxiated newborns undergoing hypothermia: from the birth to the first month of life.
BACKGROUND:
Perinatal asphyxia is a severe clinical condition affecting around four million newborns worldwide. It consists of an impaired gas exchange leading to three biochemical components: hypoxemia, hypercapnia and metabolic acidosis.
METHODS:
The aim of this longitudinal experimental study was to identify the urine metabolome of newborns with perinatal asphyxia and to follow changes in urine metabolic profile over time. Twelve babies with perinatal asphyxia were included in this study; three babies died on the eighth day of life. Total-body cooling for 72 hours was carried out in all the newborns. Urine samples were collected in each baby at birth, after 48 hours during hypothermia, after the end of the therapeutic treatment (72 hours), after 1 week of life, and finally after 1 month of life. Urine metabolome at birth was considered the reference against which to compare metabolic profiles in subsequent samples. Quantitative metabolic profiling in urine samples was measured by gas chromatography mass spectrometry (GC-MS). The statistical approach was conducted by using the multivariate analysis by means of principal component analysis (PCA) and orthogonal partial least square discriminant analysis (OPLS-DA). Pathway analysis was also performed.
RESULTS:
The most important metabolites depicting each time collection point were identified and compared each other. At birth before starting therapeutic hypothermia (TH), urine metabolic profiles of the three babies died after 7 days of life were closely comparable each other and significantly different from those in survivors.
CONCLUSIONS:
In conclusion, a plethora of data have been extracted by comparing the urine metabolome at birth with those observed at each time point collection. The modifications over time in metabolites composition and concentration, mainly originated from the depletion of cellular energy and homeostasis, seems to constitute a fingerprint of perinatal asphyxia
Diversidad y grupos funcionales de insectos en cultivos de arroz y sus bordes bajo manejo convencional y agroecológico en Santa Fe, Argentina
El arroz es el cereal de mayor producción considerado el alimento base para el 50% de la población mundial. Los objetivos del trabajo fueron i) conocer la diversidad de insectos que presentan los cultivos de arroz y sus bordes ii) caracterizar grupos funcionales según el rol ecosistémico que cumplen los insectos en cultivos de arroz y sus bordes con diferente tipo de manejo iii) analizar las interacciones de los grupos funcionales con la vegetación de los bordes. Los muestreos se realizaron durante un ciclo de producción primavera-verano (2017-2018), en cultivos de arroz con prácticas de manejo convencional (MC) y agroecológico (MA). Se capturaron 1005 ejemplares pertenecientes a 244 especies y morfoespecies. Los bordes presentaron mayor riqueza, abundancia y diversidad de Shannon en relación al cultivo, siendo el MA destacado por la presencia de los cinco grupos funcionales. En ambos manejos, se presenció Sepedonea sp., Protodictya sp. y Eryopis connexa (L.) como controladores de gasterópodos e insectos plagas. Se registraron 397 interacciones insecto-planta en MA y 175 en MC. Se destaca la importancia de los bordes y las prácticas MA en el cultivo de arroz para favorecer la conservación de entomofauna y potenciar los servicios ecosistémicos que éstos brindan a los sistemas productivos.Ecosystem services provided by insects, such as pollination and pest control, are essential for food production and agricultural health. The aims of this work were to 1) compare insect diversity in rice crops and their containment edges in two farms under different management systems (conventional and agroecological), 2) characterize functional groups of insects in rice crops and their containment edges, under different management systems, and 3) analyze the interactions of functional groups of insects with vegetation in the containment edges. Sampling was conducted during a rice production cycle in the spring-summer 2017-2018 in farms under conventional management practices (EMC) and agroecological management (EMA) in an area of intensive rice production (San Javier Department, Santa Fe, Argentina). A total of 1008 insects belonging to 236 species and morphospecies were captured using entomological nets. Containment edges exhibited higher richness, abundance and diversity than crops, with the EMA standing out for the presence of all five functional groups. On both farms, Sepedonea sp., Protodictya sp. and Eryopis connexa (L.), known control agents of gastropods and insect pests, were recorded. A total of 397 insect-plant interactions were registered in agroecological containment edges, and only 175 in conventional ones. The results obtained in this work make a novel contribution to the knowledge of insects present in containment edges and in rice crops. This work provides knowledge on the diversity, composition and distribution of the insect community, as well as data on the floral offer of the vegetation growing in containment edges and its relationship with the entomofauna.EEA RafaelaFil: Ghiglione, Carla. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias. Cátedra de EntomologÃa; ArgentinaFil: Zumoffen, Leticia. Instituto Nacional de TecnologÃa Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela. Agencia de Extensión Rural Monte Vera; ArgentinaFil: Zumoffen, Leticia. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Dalmazzo, Maria de los Milagros. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias. Cátedra de EntomologÃa; ArgentinaFil: Dalmazzo, Maria de los Milagros. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Strasser, Ruth. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias. Cátedra de EntomologÃa; ArgentinaFil: Attademo, Andres M. Universidad Nacional del Litoral. Facultad de BioquÃmica y Ciencias Biológicas. Laboratorio de EcotoxicologÃa; ArgentinaFil: Attademo, Andres M. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentin
Determinants of frontline tyrosine kinase inhibitor choice for patients with chronic-phase chronic myeloid leukemia: AÂ study from the Registro Italiano LMC and Campus CML
BackgroundImatinib, dasatinib, and nilotinib are tyrosine kinase inhibitors (TKIs) approved in Italy for frontline treatment of chronic-phase chronic myeloid leukemia (CP-CML). The choice of TKI is based on a combined evaluation of the patient's and the disease characteristics. The aim of this study was to analyze the use of frontline TKI therapy in an unselected cohort of Italian patients with CP-CML to correlate the choice with the patient's features. MethodsA total of 1967 patients with CP-CML diagnosed between 2012 and 2019 at 36 centers throughout Italy were retrospectively evaluated; 1089 patients (55.4%) received imatinib and 878 patients (44.6%) received a second-generation (2G) TKI. ResultsSecond-generation TKIs were chosen for most patients aged <45 years (69.2%), whereas imatinib was used in 76.7% of patients aged >65 years (p < .001). There was a predominant use of imatinib in intermediate/high European long-term survival risk patients (60.0%/66.0% vs. 49.7% in low-risk patients) and a limited use of 2G-TKIs in patients with comorbidities such as hypertension, diabetes, chronic obstructive pulmonary disease, previous neoplasms, ischemic heart disease, or stroke and in those with >3 concomitant drugs. We observed a greater use of imatinib (61.1%) in patients diagnosed in 2018-2019 compared to 2012-2017 (53.2%; p = .002). In multivariable analysis, factors correlated with imatinib use were age > 65 years, spleen size, the presence of comorbidities, and & GE;3 concomitant medications. ConclusionsThis observational study of almost 2000 cases of CML shows that imatinib is the frontline drug of choice in 55% of Italian patients with CP-CML, with 2G-TKIs prevalently used in younger patients and in those with no concomitant clinical conditions. Introduction of the generic formulation in 2018 seems to have fostered imatinib use
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