3,812 research outputs found

    A High-Order Scheme for Image Segmentation via a modified Level-Set method

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    In this paper we propose a high-order accurate scheme for image segmentation based on the level-set method. In this approach, the curve evolution is described as the 0-level set of a representation function but we modify the velocity that drives the curve to the boundary of the object in order to obtain a new velocity with additional properties that are extremely useful to develop a more stable high-order approximation with a small additional cost. The approximation scheme proposed here is the first 2D version of an adaptive "filtered" scheme recently introduced and analyzed by the authors in 1D. This approach is interesting since the implementation of the filtered scheme is rather efficient and easy. The scheme combines two building blocks (a monotone scheme and a high-order scheme) via a filter function and smoothness indicators that allow to detect the regularity of the approximate solution adapting the scheme in an automatic way. Some numerical tests on synthetic and real images confirm the accuracy of the proposed method and the advantages given by the new velocity.Comment: Accepted version for publication in SIAM Journal on Imaging Sciences, 86 figure

    Strange loves: a remarkable case of aberrant copulation in beetles (Coleoptera: Meloidae, Chrysomelidae)

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    A case of copulation between two mimic and repellent beetle species (a male of Timarcha fracassii, and a female of Meloe autumnalis), belonging to distinct families (Chrysomelidae, Meloidae), is recorded

    Capture and Separation, the First Step toward Circular Economy; a Regenerable, Bio-Based, Polymerized, Ionic Liquid Membranes

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    Air can be considered as a source of CO2, with concentrations of approximately 408 ppm reported in 2018 and predicted levels expected to reach 600−1550 ppm in 2030. Direct air capture (DAC) from the atmosphere is considered as a CO2 separation technology that can be realized and a source of CO2 exploitable as building block for utilization. The use of solid amines for CO2 adsorption following a two-steps process: the adsorption of CO2 from the direct air and the separation of CO2 from the sorbent. The separation of CO2 from amines is relatively easier than from strong liquid bases as it requires less energy due to the weaker bonds between CO2 and the solid sorbent. The benefit of the DAC technology is that it can be implemented anywhere because of the fast mixing of CO2 in the air. However this technique rely on the preparation of amine sorbed on solid inorganic substrate such as silica substrate and even if durable are quite difficult to regenerate once spent. Our substrate is based on polymerized ionic liquid that use as functional amino acid anions as active sorbent. Ionic liquids (ILs) are organic salts that melts below 100°C been studied as innovative material for CO2 capture. Polymerized ionic liquids (PILs) merge ILs and macromolecules peculiarities resulting in a novel class of material that features high tunability and ionic exchange ability as well as easier handling, processability typical of polymer. PILs have been studied for gas separation and demonstrated, higher CO2 loading than common ILs, as well as faster absorption/desorption rate. However, despite the chemical absorption of CO2 in ILs is a well-established concept divided as capture by chemisorption or by physisorption in PILs the majority of the studies focus on material without CO2 reactive species and no explicit reference to chemical nor physical sorption materials. Different PILs with amino acid anions were developed and tested for CO2 absorption in solid phase. The research on PILs aimed to explore different AA anions as well as different polymeric structures. Ionic exchange procedures were tuned depending on the solubility property of the starting PIL with several AA. All synthetic procedures aimed to avoid toxic and hazardou chemicals. Obtained PILs were identified and were tested for CO2 and water absorption and desorption

    Analysis of the interaction of calcitriol with the disulfide isomerase ERp57

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    Calcitriol, the active form of vitamin D3, can regulate the gene expression through the binding to the nuclear receptor VDR, but it can also display nongenomic actions, acting through a membrane- associated receptor, which has been discovered as the disul de isomerase ERp57. The aim of our research is to identify the binding sites for calcitriol in ERp57 and to analyze their interaction. We rst studied the interaction through bioinformatics and uorimetric analyses. Subsequently, we focused on two protein mutants containing the predicted interaction domains with calcitriol: abb’- ERp57, containing the rst three domains, and a’-ERp57, the fourth domain only. To consolidate the achievements we used the calorimetric approach to the whole protein and its mutants. Our results allow us to hypothesize that the interaction with the a’ domain contributes to a greater extent than the other potential binding sites to the dissociation constant, calculated as a Kd of about 10−9 M

    Hepatotoxicity induced by greater celandine (Chelidonium majus L.): a review of the literature

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    The available literature assessing Chelidonium majus L. (CM) hepatotoxicity potential, and its risk to benefit assessment has been reviewed in this paper. Identification of significant scientific literature was performed via the following research databases: Cochrane Central, Google Scholar, EMBASE, Medline, Science Direct, Scopus, Web of Science, using the following keywords: "Chelidonium majus", "greater celandine", "Hepatotoxicity", "Liver" "Injury", "Toxicity" individually investigated and then again in association. CM named also greater celandine, swallow-wort, or bai-qu-cai (Chinese), has been used for a long time in traditional Chinese medicine and phytotherapy. Its extracts have been claimed to display a wide variety of biological activities: antimicrobial, anti-inflammatory, spasmolytic, antineoplastic, hepatoprotective, and analgesic. Moreover, herbal medicine suggests this plant have numerous additional effects which have not yet been scientifically evaluated, such as antitussive, diuretic, and eye-regenerative. However, despite its claimed hepatoprotective effects, several hepatotoxicity cases have been reported to be probably or highly probably connected with CM exposure, after their evaluation through liver-targeted causality assessment methods. CM hepatotoxicity has been defined as a distinct form of herb-induced liver injury (HILI), due to an idiosyncratic reaction of the metabolic type. This evidence has to be considered in relationship with the absence of considerable benefits of CM therapy. Therefore, the risk to benefit ratio of the use of herbal products containing greater celandine can actually be considered as negative

    SOCIAL AND CLINICAL DETERMINANTS OF COMPULSORY AND VOLUNTARY ADMISSIONS WITHIN THE FRAMEWORK OF AN ITALIAN COMMUNITY MENTAL HEALTH SYSTEM

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    Social and clinical determinants of 30 compulsory admissions (CAs) to a psychiatric ward during a six-month period were compared to 134 voluntary admissions (VAs), and outcomes of hospitalisation were assessed in relation to its types. Psychosocial and clinical characteristics at admission and discharge were measured using 5 scales. Unemployment, hospitalisations >7 days and continuing hospitalisation in Community Mental Health Centres were positively associated with CA. At admission, CAs showed lower functioning, while outcome at discharge was similar. Social determinants had a main role in determining CAs. Clinical and psychosocial outcomes might have been improved by a mental health system community-based

    Improved time-resolved measurements of inorganic ions in particulate matter by PILS-IC integrated with a sample pre-concentration system

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    A particle-into-liquid sampler coupled with ion chromatograph (PILS-IC) for the on-line measurement of inorganic ions has been modified by the insertion of two ion-exchange pre-concentration cartridges that enrich the sample during the period of the IC analysis. The limits of detection of the modified instrument were 10-15 times lower and the time coverage 24 times higher (from 2 to 48 min per hour) than those of the original PILS-IC setup. The instrumental performance in terms of recovery and break-through volume from the cartridges was satisfactory. The modified PILS-IC was operated in comparison with a diffusion denuder line and with a high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS) during a short intensive measurement period organized in the framework of the European Monitoring and Evaluation Programme (EMEP), a co-operative program for monitoring and evaluation of the long-range transmission of the air pollutants in Europe. The instrument showed a quantitative response in agreement with the results of the diffusion lines, and an ability to trace fine concentration variations not so different from the performance of the much more complex HR-TOF-AMS. From the time patterns of the ion concentrations measured by the modified PILS-IC, it was possible to obtain useful information about the variations in the air quality and in the strength of the particulate matter sourc

    Denervation does not induce muscle atrophy through oxidative stress

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    Denervation leads to the activation of the catabolic pathways, such as the ubiquitin-proteasome and autophagy, resulting in skeletal muscle atrophy and weakness. Furthermore, denervation induces oxidative stress in skeletal muscle, which is thought to contribute to the induction of skeletal muscle atrophy. Several muscle diseases are characterized by denervation, but the molecular pathways contributing to muscle atrophy have been only partially described. Our study delineates the kinetics of activation of oxidative stress response in skeletal muscle following denervation. Despite the denervation-dependent induction of oxidative stress in skeletal muscle, treatments with anti-oxidant drugs do not prevent the reduction of muscle mass. Our results indicate that, although oxidative stress may contribute to the activation of the response to denervation, it is not responsible by itself of oxidative damage or neurogenic muscle atrophy

    Peroxynitrite activates the NLRP3 inflammasome cascade in SOD1(G93A) mouse model of amyotrophic lateral sclerosis

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    Neuroinflammation, characterized by the appearance of reactive microglial and astroglial cells, is one of the several pathogenic mechanisms of amyotrophic lateral sclerosis (ALS), a fast-progressing and fatal neurodegenerative disease. Cerebrospinal fluid and spinal cord of ALS patients and SOD1 mutant mice show high concentrations of IL-1β. This interleukin, expressed as an inactive precursor, undergoes a proteolytic maturation by caspase1, whose activation, in turn, depends on inflammasomes. Whether and how inflammasome is activated in ALS models is still to be clarified. The mechanism of inflammasome activation was studied in murine microglial cells overexpressing hSOD1(G93A) and verified in the spinal cord of hSOD1(G93A) mice. Murine microglial hSOD1(G93A) cells express all the inflammasome components and LPS activates caspase1 leading to an increase in the secretion of IL-1β. By activating NF-κB, LPS increases ROS and NO levels that spontaneously react to form peroxynitrite, thus leading to protein nitration. Reduction in peroxynitrite levels results in a decrease in caspase1 activity. Protein nitration and caspase1 activity are concomitantly increased in the spinal cord of pre-symptomatic SOD1(G93A) mice. Oxidative/nitrosative stress induces peroxynitrite formation that may be a key trigger of caspase1/inflammasome activation. Peroxynitrite formation may play a critical role in inflammasome activation and might be exploited as potential therapeutic target for ALS
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