Finite Element Modeling of Bond Behavior of FRP and Steel Plates

Strengthening systems for existing reinforced concrete (RC) structures are increasingly needed due to several problems such as degradation of materials over the time, underdesign, serviceability or seismic upgrading, or new code requirements. In the last decades, strengthening by fibers composite materials applied with various techniques (FRP, FRCM, NSM) were largely investigated and theoretical formulations have been introduced in national and international design guidelines. Although they are an excellent strengthening solution, steel plates may represent still a valid traditional alternative, due to low costs, ductile stress-strain behavior, simple and fast mounting with possibility of reusing the material. Guidelines for a correct design are still lack and, therefore, detailed models and design formulas are needed. In this paper, the bond behavior at the plate-concrete interface, which plays a key role for the effectiveness of the strengthening system, is analyzed by means of 3D finite element models calibrated on experimental results available in literature. Parametric analyses were carried out by changing some meaningful parameters

NMR approach for monitoring post-mortem changes in Atlantic salmon fillets stored at 0 and 4°C

High resolution NMR technique has been used to monitor post-mortem changes in salmon (Salmo salar) fillets upon storage at 4 and 0 °C. Thirty-one different fish metabolites influencing freshness and taste properties have been unequivocally assigned by NMR using either available standard compounds or ad hoc acquired 2D 1H–1H TOCSY and 1H–13С HSQC spectra. The monitored fish metabolites include amino acids, dipeptides, sugars, vitamins, biogenic amines, as well as different products of the ATP degradation. The detection and monitoring of biogenic amines by NMR, upon fish storage, is information of interest for consumers, since some of these compounds are toxic. The data from this study shows that NMR spectroscopy also provides the amount of all metabolites necessary for the calculation of the K-index used to express fish freshness. A good correlation was found between the K-index increase and the formation of the undesired biogenic amines. The metabolite concentrations and the K-index found in this work were compared and found coherent with literature data. The performed study reveals the strengths and the suitability of the NMR approach to monitor different biochemical processes occurring during fish storage and qualitatively and quantitatively characterise fish metabolites determining fish quality

ARIANNA: A research environment for neuroimaging studies in autism spectrum disorders

The complexity and heterogeneity of Autism Spectrum Disorders (ASD) require the implementation of dedicated analysis techniques to obtain the maximum from the interrelationship among many variables that describe affected individuals, spanning from clinical phenotypic characterization and genetic profile to structural and functional brain images. The ARIANNA project has developed a collaborative interdisciplinary research environment that is easily accessible to the community of researchers working on ASD (https://arianna.pi.infn.it). The main goals of the project are: to analyze neuroimaging data acquired in multiple sites with multivariate approaches based on machine learning; to detect structural and functional brain characteristics that allow the distinguishing of individuals with ASD from control subjects; to identify neuroimaging-based criteria to stratify the population with ASD to support the future development of personalized treatments. Secure data handling and storage are guaranteed within the project, as well as the access to fast grid/cloud-based computational resources. This paper outlines the web-based architecture, the computing infrastructure and the collaborative analysis workflows at the basis of the ARIANNA interdisciplinary working environment. It also demonstrates the full functionality of the research platform. The availability of this innovative working environment for analyzing clinical and neuroimaging information of individuals with ASD is expected to support researchers in disentangling complex data thus facilitating their interpretation

Targeting STAT1 by myricetin and delphinidin provides efficient protection of the heart from ischemia/reperfusion-induced injury

AbstractFlavonoids exhibit a variety of beneficial effects in cardiovascular diseases. Although their therapeutic properties have been attributed mainly to their antioxidant action, they have additional protective mechanisms such as inhibition of signal transducer and activator of transcription 1 (STAT1) activation. Here, we have investigated the cardioprotective mechanisms of strong antioxidant flavonoids such as quercetin, myricetin and delphinidin. Although all of them protect the heart from ischemia/reperfusion-injury, myricetin and delphinidin exert a more pronounced protective action than quercetin by their capacity to inhibit STAT1 activation. Biochemical and computer modeling analysis indicated the direct interaction between STAT1 and flavonoids with anti-STAT1 activity

Assessment of Astaxanthin Accumulation in Hepatocytes of Atlantic Salmon Fed Different Diets Using NMR Spectroscopy

This study aimed to assess the astaxanthin (Ax) accumulation in hepatocytes isolated from farmed Atlantic salmon fed different diets (rich marine, poor, poor with marine phospholipids (MPL) and poor with docosahexaenoic acid (DHA)). Nuclear magnetic resonance (NMR) spectroscopy was used for the Ax detection and quantification. The use of the 13C-enriched Ax allowed the assessment of short-time Ax metabolism. The substitution of fish oil and meal in fish feed on plant analogs and the addition of MPL caused further catabolism and decrease of Ax accumulation in hepatocytes from 17 to about 6 mg/kg or to almost zero in the case of DHA addition. Signals assignment of the native and 13C-enriched astaxanthin in acetone were performed using 1D and 2D NMR spectra.publishedVersio

Assessment of Astaxanthin Accumulation in Hepatocytes of Atlantic Salmon Fed Different Diets Using NMR Spectroscopy

This study aimed to assess the astaxanthin (Ax) accumulation in hepatocytes isolated from farmed Atlantic salmon fed different diets (rich marine, poor, poor with marine phospholipids (MPL) and poor with docosahexaenoic acid (DHA)). Nuclear magnetic resonance (NMR) spectroscopy was used for the Ax detection and quantification. The use of the 13C-enriched Ax allowed the assessment of short-time Ax metabolism. The substitution of fish oil and meal in fish feed on plant analogs and the addition of MPL caused further catabolism and decrease of Ax accumulation in hepatocytes from 17 to about 6 mg/kg or to almost zero in the case of DHA addition. Signals assignment of the native and 13C-enriched astaxanthin in acetone were performed using 1D and 2D NMR spectra

Bond tests on concrete elements externally bonded with steel plates and assessment of bond strength models

The use of steel plates as externally bonded reinforcement for existing reinforced concrete (RC) elements can be still considered a reliable typology of strengthening intervention thanks to their relatively lower prices in comparison with fiber reinforced plastic materials, FRPs, largely used in the last decades, the ductile stress–strain behavior, and the high stiffness properties. Despite steel plates represented the first attempt of external strengthening for RC elements, design indications and practical execution rules concerning the use of such a technique nowadays are still very few. There is, indeed, a lack of experimental and theoretical studies in literature for predicting accurately the behavior of existing RC members externally strengthened with steel plates. In particular, special attention should be paid to the bond behavior at the steel–concrete interface, since it can strongly influence the performance of the strengthened elements. To this aim, an experimental campaign concerning bond tests on steel plates bonded over concrete elements and realized according to the single shear test set-up was carried out by the Authors. The experimental results are analyzed in the paper in terms of failure loads and modes, load–displacement behaviour, axial strain distributions along the steel plates, and distribution of shear stresses and slips. Then, the experimental results are compared with some well-known literature bond strength models for external FRP reinforcements in terms of failure load, transfer length and bond law. The comparisons with existing models in terms of debonding loads are developed also for an extended database of bond tests on steel plates available in literature and were prodromal to calibrate new coefficients specifically assessed for externally bonded steel plates

The foodomics approach for the evaluation of protein bio-accessibility in processed meat upon in vitro digestion

The present work describes a foodomics protocol coupling an in vitro static simulation of digestion to a combination of omics techniques, to grant an overview of the protein digestibility of a meat based food, namely Bresaola. The proteolytic activity mediated by the digestive enzymes is evaluated through Bradford and SDS-PAGE assays, combined to NMR relaxometry and spectroscopy, to obtain information ranging from the microscopic to the molecular level,respectively. The simple proteomics tool here adopted points out that a clear increase of bioaccessible proteins occurs in the gastric phase, rapidly disappearing during the following duodenal digestion. However, SDS-PAGE and the Bradford assay cannot follow the fate of the digested proteins when the products are sized below 5 kDa. Conversely, NMR spectroscopy is able to capture the overall molecular profile of small fragments and peptides which are mainly formed during the duodenal phase, thus giving the kinetics of the whole digestion process. TD-NMR relaxometry, finally, detects the swelling phenomenon occurring during the gastric phase, when the digestion fluid enters the meat matrix

STAT-1 as a new molecular target of anti-inflammatory treatment.

Cyclooxygenase (COX) is widely considered as the molecular target of non-steroid anti-inflammatorydrugs (NSAIDs). However, due to the harmful side effect frequently observed following chronic use, thedevelopment of new anti-inflammatory agents is the matter of many studies.Signal transducers and activators of transcription (STAT) are a family of nuclear proteins mediating the action ofa number of cytokines. Among them, STAT1 plays a critical role in the signal transduction pathway ofinterferon-gamma (IFN-gamma) and growth hormone. STAT1 cascade is one major signalling pathwayconverting the IFN-gamma signal into gene expression, such as inducible nitric oxide synthase (iNOS), COX,vascular cell adhesion molecules (VCAM) and intercellular cell adhesion molecules (ICAM), critically involvedin different pathologies correlated to the inflammatory process.This review focuses the attention on an alternative approach to the development of novel drugs based oninhibition of STAT1 pathway.In this context, a growing interest has been focused on natural compounds. We have recently reported a severaldata indicating that green tea extract (GTE), St. John\u2019s Wort extract and epigallocatechin-3-gallate (EGCG)exhibit a specific and strong anti-STAT1 activity which is independent of their acclaimed strong anti-oxidantactivity. More recently, GTE has been shown to protect heart damage from ischaemia/reperfusion in rats,suggesting that the protective effect of green tea might be correlated to its anti-STAT1 activity.The present review is aimed at providing data that STAT1 may potentially be claimed as a new molecular targetof an anti-inflammatory treatment and that among natural compounds there are a number of anti-STAT1substances