193 research outputs found

    Quasi-static and low-velocity impact behavior of intraply hybrid flax/basalt composites

    Get PDF
    In an attempt to increase the low-velocity impact response of natural fiber composites, a new hybrid intraply woven fabric based on flax and basalt fibers has been used to manufacture laminates with both thermoplastic and thermoset matrices. The matrix type (epoxy or polypropylene (PP) with or without a maleated coupling agent) significantly affected the absorbed energy and the damage mechanisms. The absorbed energy at perforation for PP-based composites was 90% and 50% higher than that of epoxy and compatibilized PP composites, respectively. The hybrid fiber architecture counteracted the influence of low transverse strength of flax fibers on impact response, irrespective of the matrix type. In thermoplastic laminates, the matrix plasticization delayed the onset of major damage during impact and allowed a better balance of quasi-static properties, energy absorption, peak force, and perforation energy compared to epoxy-based composites

    Assessing the (In)Stability of Urban Art Paints: From Real Case Studies to Laboratory Investigations of Degradation Processes and Preservation Possibilities

    Get PDF
    Urban art as a shared expression of street art between artists, citizenship and municipalities has always had an important role in the social life and appearance of modern cities. However, the durability of urban and street artworks is susceptible to the degradation processes that the employed commercial paint formulations undergo once outdoors. These are complex mixtures of compounds, differently sensitive to environmental agents according to their chemical nature. Starting from the colorimetric analysis of murals created in 2010, 2011 and 2018 in Reggio Emilia, Italy, documenting their degradation already after a few months, this study aimed at understanding the stability of the most unstable paints used by the artists in these artworks. A multi-analytical approach evaluated the commercial products under the chemical point of view, after natural and accelerated ageing. Additionally, two manufactured anti-UV varnishes were evaluated for their possible use as coatings. The results pinpointed the weaknesses of the selected paints and highlighted how the application of an anti-UV coating might slightly affect the visual aspect of the artwork, though ensuring a greater resistance to the outdoor conditions due to their minor chemical sensitivity to environmental agents

    Behavioral Phenotyping of Dopamine Transporter Knockout Rats: Compulsive Traits, Motor Stereotypies, and Anhedonia

    Get PDF
    Alterations in dopamine neurotransmission are generally associated with diseases such as attention-deficit/hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD). Such diseases typically feature poor decision making and lack of control on executive functions and have been studied through the years using many animal models. Dopamine transporter (DAT) knockout (KO) and heterozygous (HET) mice, in particular, have been widely used to study ADHD. Recently, a strain of DAT KO rats has been developed (1). Here, we provide a phenotypic characterization of reward sensitivity and compulsive choice by adult rats born from DAT-HET dams bred with DAT-HET males, in order to further validate DAT KO rats as an animal model for preclinical research. We first tested DAT KO rats' sensitivity to rewarding stimuli, provided by highly appetitive food or sweet water; then, we tested their choice behavior with an Intolerance-to-Delay Task (IDT). During these tests, DAT KO rats appeared less sensitive to rewarding stimuli than wild-type (WT) and HET rats: they also showed a prominent hyperactive behavior with a rigid choice pattern and a wide number of compulsive stereotypies. Moreover, during the IDT, we tested the effects of amphetamine (AMPH) and RO-5203648, a trace amine-associated receptor 1 (TAAR1) partial agonist. AMPH accentuated impulsive behaviors in WT and HET rats, while it had no effect in DAT KO rats. Finally, we measured the levels of tyrosine hydroxylase, dopamine receptor 2 (D2), serotonin transporter, and TAAR1 mRNA transcripts in samples of ventral striatum, finding no significant differences between WT and KO genotypes. Throughout this study, DAT KO rats showed alterations in decision-making processes and in motivational states, as well as prominent motor and oral stereotypies: more studies are warranted to fully characterize and efficiently use them in preclinical research

    miR-214 coordinates melanoma progression by upregulating ALCAM through TFAP2 and miR-148b downmodulation

    Get PDF
    Malignant melanoma is one of the most aggressive human cancers, but the mechanisms governing its metastatic dissemination are not fully understood. Upregulation of miR-214 and ALCAM and the loss of TFAP2 expression have been implicated in this process, with TFAP2 a direct target of miR-214. Here, we link miR-214 and ALCAM as well as identify a core role for miR-214 in organizing melanoma metastasis. miR- 214 upregulated ALCAM, acting transcriptionally through TFAP2 and also posttranscriptionally through miR-148b (itself controlled by TFAP2), both negative regulators of ALCAM. We also identified several miR-214–mediated prometastatic functions directly promoted by ALCAM. Silencing ALCAM in miR-214–overexpressing melanoma cells reduced cell migration and invasion without affecting growth or anoikisin vitro, and it also impaired extravasation and metastasis formation in vivo. Conversely, cell migration and extravasation was reduced in miR-214–overexpressing cells by upregulation of either miR 148b or TFAP2. These findings were consistent with patterns of expression of miR-214, ALCAM, and miR-148b in human melanoma specimens. Overall, our results define a pathway involving miR-214, miR-148b, TFAP2, and ALCAM that is critical for establishing distant metastases in melanoma

    Hemopexin Therapy Improves Cardiovascular Function by Preventing Heme-Induced Endothelial Toxicity in Mouse Models of Hemolytic Diseases

    Get PDF
    Background-Hemolytic diseases are characterized by enhanced intravascular hemolysis resulting in heme-catalyzed reactive oxygen species generation, which leads to endothelial dysfunction and oxidative damage. Hemopexin (Hx) is a plasma heme scavenger able to prevent endothelial damage and tissue congestion in a model of heme overload. Here, we tested whether Hx could be used as a therapeutic tool to counteract heme toxic effects on the cardiovascular system in hemolytic diseases. Methods and Results\u2014By using a model of heme overload in Hx-null mice, we demonstrated that heme excess in plasma, if not bound to Hx, promoted the production of reactive oxygen species and the induction of adhesion molecules and caused the reduction of nitric oxide availability. Then, we used \u3b2-thalassemia and sickle cell disease mice as models of hemolytic diseases to evaluate the efficacy of an Hx-based therapy in the treatment of vascular dysfunction related to heme overload. Our data demonstrated that Hx prevented heme-iron loading in the cardiovascular system, thus limiting the production of reactive oxygen species, the induction of adhesion molecules, and the oxidative inactivation of nitric oxide synthase/nitric oxide, and promoted heme recovery and detoxification by the liver mainly through the induction of heme oxygenase activity. Moreover, we showed that in sickle cell disease mice, endothelial activation and oxidation were associated with increased blood pressure and altered cardiac function, and the administration of exogenous Hx was found to almost completely normalize these parameters. Conclusions-Hemopexin treatment is a promising novel therapy to protect against heme-induced cardiovascular dysfunction in hemolytic disorders

    A Comprehensive and Systematic Diagnostic Campaign for a New Acquisition of Contemporary Art—The Case of Natura Morta by Andreina Rosa (1924–2019) at the International Gallery of Modern Art Ca’ Pesaro, Venice

    Get PDF
    A multi-analytical approach has been employed to investigate the painting Natura Morta (1954–1955) by Andreina Rosa (1924–2019) to assess the state of conservation and to understand more about the painting materials and techniques of this artwork, which was recently donated by the painter’s heirs to the International Gallery of Modern Art Ca’ Pesaro (Venice-Italy). A comprehensive and systematic diagnostic campaign was carried out, mainly adopting non-invasive imaging and spectroscopic methods, such as technical photography, optical microscopy, Hyperspectral Imaging Spectroscopy (HIS), fiber optics reflectance spectroscopy (FORS), External Reflectance Fourier Transform Infrared (ER-FTIR), and Raman spectroscopies. Microsamples, collected from the edges of the canvas in areas partially detached, were studied by Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy and Gas Chromatography-Mass Spectrometry (GC-MS). By crossing the information gained, it was possible to make inferences about the composition of the groundings and the painted layers, the state of conservation of the artwork, and the presence of degradation phenomena. Hence, the present study may be of interest for conservation purposes as well as for enhancing the artistic activity of Andreina Rosa. The final aim was to provide useful information for the Gallery which recently included this painting in its permanent collection

    COVID-19 Lockdown Impacts Among Patients with Cystic Fibrosis: An Italian Regional Reference Centre Experience

    Get PDF
    Coronavirus pandemic has influenced our society with social distancing and management of chronic disease such as cystic fibrosis (CF). During the Italian lockdown from March to May 2020, CF patients reduced the number of outpatient visits, limited social interactions and spent more time at home. The aim of this study is to evaluate the impact of the lockdown on body mass index (BMI) and lung function tests on CF patients.We retrospectively reviewed clinical data about 111 CF patients followed in our Regional Cystic Fibrosis Reference Centre (Policlinico Umberto I, Rome) according to two periods: pre-lockdown (from October 2019-March 2020) and post-lockdown (from May 2020-October 2020). We collected data on nutritional (BMI and body weight) and lung function status; we chose the best values of the 'pre-lockdown' and 'post-lockdown' period for each patient. Patients were divided into 3 groups according to FEV1 value (Forced Expiratory Volume in the 1st second): group 1 (FEV140%), group 2 (FEV1 40-70%), group 3 (FEV170%). All patients received a telephone interview asking for the number of hours per week devoted to physical activity, number of pulmonary acute exacerbations and subjective evaluation of adherence to medical therapy, respiratory physiotherapy and diet, during the two periods.Comparing weight, BMI and respiratory function between pre and post lockdown periods, we noticed an increase in weight during among overall patients. Male patients improved weight, BMI, FEF 25-75% (Forced Expiratory flow between 25% and 75% of vital capacity) and Tiffenau index more than female patients. The most severely compromised patients (group 1), showed a significant loss of both weight and BMI. Instead, patients with moderate respiratory function (group 2) showed a significant increase of both weight and BMI and a slightly reduced CVF (Forced Vital capacity). We found no differences among patients with good respiratory function (group 3). Comparing each clinical sub-groups, we noticed a significative improvement of weight (Lockdown period had benefit among CF patients in terms of weight in particular in male patient. The greatest benefit on nutritional state was observed in patients with moderate reduction of respiratory function. In addition, we noted a stabilization and sometimes a slight improvement of lung function, instead of a continuous and steady decline that is normally observed in CF patients. These beneficial effects are slight but significative, bearing in mind the general worsening that CF patients experience annually

    Tunable supramolecular chirogenesis in the self-assembling of amphiphilic porphyrin triggered by chiral amines

    Get PDF
    Supramolecular chirality is one of the most important issues in different branches of science and technology, as stereoselective molecular recognition, catalysis, and sensors. In this paper, we report on the self-assembly of amphiphilic porphyrin derivatives possessing a chiral information on the periphery of the macrocycle (i.e., D- or L-proline moieties), in the presence of chiral amines as co-solute, such as chiral benzylamine derivatives. The aggregation process, steered by hydrophobic effect, has been studied in aqueous solvent mixtures by combined spectroscopic and topographic techniques. The results obtained pointed out a dramatic effect of these ligands on the morphology and on the supramolecular chirality of the final self-assembled structures. Scanning electron microscopy topography, as well as fluorescence microscopy studies revealed the formation of rod-like structures of micrometric size, different from the fractal structures formerly observed when the self-assembly process is carried out in the absence of chiral amine co-solutes. On the other hand, comparative experiments with an achiral porphyrin analogue strongly suggested that the presence of the prolinate moiety is mandatory for the achievement of the observed highly organized suprastructures. The results obtained would be of importance for unraveling the intimate mechanisms operating in the selection of the homochirality, and for the preparation of sensitive materials for the detection of chiral analytes, with tunable stereoselectivity and morphology

    Non-infectious uveitis burden on quality of life and work impairment assessed through different psychometric questionnaires

    Get PDF
    Background: The purpose of this study was to evaluate the association between a novel psychometric 12-item questionnaire (U-qest) and other validated questionnaires to assess quality of life and work impairment in patients with non-infectious uveitis. Methods: Data were collected at baseline and 3 months postbaseline using U-qest and two other validated questionnaires: The National Eye Institute 25-Item Visual Function Questionnaire (VFQ-25) and the 12-Item Short-Form Health Survey (SF-12). Results: A total of 136 patients (52.2% female) aged 47.9 ± 14.8 years (mean ± SD) were enrolled in 14 uveitis referral centres. U-qest correlated moderately with VFQ-25 and SF-12 at baseline and at 3 months. Both U-qest and VFQ-25 scores improved as disease improved; however, U-qest also detected improvement in patients for whom VFQ-25 scores did not improve. Disease activity was shown to significantly affect activity impairment. Patients and physicians expressed positive perceptions regarding the use and benefit of this instrument. U-qest showed very good reliability in terms of internal consistency (Cronbach’s alpha = 0.91). Conclusions: U-qest can be considered a useful tool to assess the burden of uveitis on quality of life
    corecore