Search results for "ASPH"
showing 10 items of 217 documents
In vitro colonic fermentation of a plant sterol-enriched beverage in a dynamic-colonic gastrointestinal digester
2021
Abstract The impact of a plant sterol-enriched beverage on the sterol metabolism, organic acid production and microbiota composition was evaluated by means of a dynamic gastrointestinal and colonic fermentation model. After one week of fermentation, an absence of sterol metabolites was reported, in accordance with the lack of microbiota related to their metabolism. Although total organic acid content was lower in the ascending colon (AC) compared to the transversal (TC) and descending colon (DC) (28–57 mmol/L vs. 55-87 and 44–64 mmol/L, respectively), its increments, with respect to the initial value, were higher (2-fold vs. 1.6- and 1.5-fold). Increments of acetate, butyrate and propionate…
Impact Analysis Using Life Cycle Assessment of Asphalt Production from Primary Data
2020
Road construction and maintenance have a great impact on the environment, owing to the huge volumes of resources involved. Consequently, current production procedures and technologies must be properly investigated, for identifying and quantifying the life cycle environmental impacts produced. In this paper, primary data, i.e., site-specific data directly collected or measured on a reference plant, are analyzed for calculating the impact of the production of a hot mix asphalt. The analysis is performed in a from &ldquo
Procedure for a Temperature-Traffic Model on Rubberized Asphalt Layers for Roads and Railways
2017
The impact of temperature on the mechanical properties and thermal susceptibility of the railway bituminous sub-ballast layer, has served as motivation to develop the advanced measurement of thermal cycles in this layer and, an evaluation of the average seasonal temperatures interpolated by sinusoidal functions, of which characteristic parameters are determined. According to weather situation, Barber’s temperature model was used to prove the effectiveness for the railway superstructure. It is included the assessment of improved modified asphalt mixes performed with coarse rubber from scrap tires, having 1.5 to 3 percent of crumb rubber (particle size 0.2-4 mm) by weight of the total mix, as…
7,8-hydroxy-2′-deoxyguanosine/2′-deoxiguanosine ratio determined in hydrolysates of brain DNA by ultrachromatrography coupled to tandem mass spectrom…
2017
7,8-hydroxy-2'-deoxyguanosine (8-OHdG) is an abundant DNA lesion formed by oxidation of the nucleoside 2'-deoxyguanosine (2-dG) and one of the most studied and accepted oxidative stress biomarkers. 8-OHdG has a strong carcinogenic potential, and prolonged oxidative stress heightens pathological conditions and especially cancer risk. Our aim was to develop, validate and apply a reliable method to assess DNA oxidation in genomic cellular DNA of sensible target organs such as brain. A procedure to isolate and digest the DNA of brain tissue properly for further detection of 8-OHdG and 2-dG by Ultra Performance Liquid Chromatography tandem Mass Spectrometry (UPLC-MS/MS) was optimized. The UPLC-M…
Surge of Peripheral Arginine Vasopressin in a Rat Model of Birth Asphyxia
2018
Mammalian birth is accompanied by a period of obligatory asphyxia, which consists of hypoxia (drop in blood O2 levels) and hypercapnia (elevation of blood CO2 levels). Prolonged, complicated birth can extend the asphyxic period, leading to a pathophysiological situation, and in humans, to the diagnosis of clinical birth asphyxia, the main cause of hypoxic-ischemic encephalopathy (HIE). The neuroendocrine component of birth asphyxia, in particular the increase in circulating levels of arginine vasopressin (AVP), has been extensively studied in humans. Here we show for the first time that normal rat birth is also accompanied by an AVP surge, and that the fetal AVP surge is further enhanced in…
Methods for assessing the severity of perinatal asphyxia and early prognostic tools in neonates with hypoxic-ischemic encephalopathy treated with the…
2020
Despite the progress in perinatal care, perinatal asphyxia (PA) remains a significant problem in neonatology. The development of therapeutic hypothermia (TH) has improved the prognosis, but it still remains uncertain in hypoxic neonates. The evaluation of the severity of ischemia/hypoxia after birth is crucial to the choice of treatment, and with accurate long-term prognosis, appropriate further patient care can be planned. This article presents various methods for the preliminary assessment of brain damage and prognosis in newborns with PA treated with TH. The importance of assessing the neurological condition and the usefulness of laboratory and electrophysiological testing and imaging ar…
Are we correctly measuring the rotational viscosity of heterogeneous bituminous binders?
2020
Modified bituminous binders allow asphalt technologists to design asphalt mixtures with superior performance. However, several recent studies highlighted that due to the complexity of these material, their characterisation can be challenging since common procedures used to characterise neat bitumen might not be adequate. For instance, during high temperature rotational viscosity testing of recycled tyre rubber modified binders (RTR-MB), a number of changes may occur to the sample leading to the here-defined sample stability which in turn provides misleading results. In this study the authors want to first provide a deeper understanding of this phenomenon by a numerical analysis using a besp…
Reclaimed asphalt binders and mortars fatigue behaviour
2017
Fatigue cracking is one of the most important failure mechanisms occurring in asphalt pavements, especially when mixtures incorporate considerable amount of rReclaimed asphalt pavement (RAP). In fact, aged binders contained in RAP generally make asphalt more brittle and specifically reduce fatigue resistance of the resulting asphalt mixtures. Binders and mortars play a key role in this phenomenon, considering fatigue cracking usually starts within these asphalt components. However, performance-related tests and specifications commonly regard binders and there are no sound methodologies allowing the use of mortars to predicting fatigue performance of asphalts containing RAP. For this reason,…
Rheological characterisation of cold bitumen emulsion slurries
2021
The performance of cold bitumen emulsion (CBE) mixtures is strongly linked to an optimised design of the binder blends and mastics. Types and dosages of bitumen, mineral additions and the workability must be characterised and optimised. This study aims at providing an approach for the fundamental characterisation of CBE materials using rotational viscometry. Firstly, a procedure for measuring the viscosity of CBE slurries using the Brookfield viscometer was investigated by comparing results obtained by using a traditional spindle geometry and a novel impeller engineered to avoid phase separation: the dual helical ribbon (DHR). Afterwards, the effect of mineral additions and bitumen emulsion…
A practical approach to estimate the degree of binder activity of reclaimed asphalt materials
2019
Using Reclaimed Asphalt (RA) in new asphalt mixtures can reduce the amount of new material required thereby saving money and natural resources. In addition, asphalt mixtures with RA have shown comparable properties and performance to that generally associated with asphalt mixtures made with 100% virgin material. However, RA content in pavement surface layers is still limited due to specification and technical limitations. For higher contents, the aged RA binder must be analysed to accurately determine the requirements for virgin binders and additives while the degree of blending (DOB) between the RA binder and the virgin binder also needs to be quantified. This is not a simple process and g…