35 research outputs found

    Design, preparation and characterization of ulvan based thermosensitive hydrogels

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    The present study is focused on the exploitation and conversion of sulphated polysaccharides obtainedfrom waste algal biomass into high value added material for biomedical applications. ulvan, a sulphatedpolysaccharide extracted from green seaweeds belonging to Ulva sp. was selected as a suitable materialdue to its chemical versatility and widely ascertained bioactivity. To date the present work representsthe first successful attempt of preparation of ulvan-based hydrogels displaying thermogelling behaviour.ulvan was provided with thermogelling properties by grafting poly(N-isopropylacrylamide) chains ontoits backbone as thermosensitive component. To this aim ulvan was properly modified with acryloylgroups to act as macroinitiator in the radical polymerization of N-isopropylacrylamide, induced by UVirradiation through a “grafting from” method. The thermogelling properties of the copolymer were inves-tigated by thermal and rheological analyses. Sol–gel transition of the copolymer was found to occur at30–31◩C thus indicating the feasibility of ulvan for being used as in-situ hydrogel forming systems forbiomedical application

    Signal-to-Noise Ratio importance in Apparent Diffusion Coefficient measurements using Diffusion-Weighted Echo-Planar-Imaging scans

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    Purpose: To define experimental grounds for Apparent Diffusion Coefficient (ADC) measurements using Spin-Echo Diffusion-Weighted Echo-Planar (SE-DW-EPI) sequences, as a function of Signal-to-Noise Ratio (SNR). Methods: multiple multi-b SE-DW-EPI scans with the same parameters but the lipid suppression technique have been compared on water phantom with a 3T MRI equipment. The SNR has been estimated using the method of difference. Images have been analyzed manually, comparing the signal intensities at different b-values. Results: All measurements show a high repeatability and strong self-consistency. A significant dependence of the ADC on SNR has been shown, and its lowest limitto obtain reliable quantitative answers has been stated. Conclusion: ADC measurements in vivo must be carefully designed to avoid systematic errors during acquisition and post-processing due to low SNR

    Dosimetric impact of different multileaf collimators on prostate intensity modulated treatment planning

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    AimThe main purpose of this study is to perform a dosimetric comparison on target volumes and organs at risks (OARs) between prostate intensity modulated treatment plans (IMRT) optimized with different multileaf collimators (MLCs).BackgroundThe use of MLCs with a small leaf width in the IMRT optimization may improve conformity around the tumor target whilst reducing the dose to normal tissues.Materials and methodsTwo linacs mounting MLCs with 5 and 10[[ce:hsp sp="0.25"/]]mm leaf-width, respectively, implemented in Pinnacle3 treatment planning system were used for this work. Nineteen patients with prostate carcinoma undergoing a radiotherapy treatment were enrolled. Treatment planning with different setup arrangements (7 and 5 beams) were performed for each patient and each machine. Dose volume histograms (DVHs) cut-off points were used in the treatment planning comparison.ResultsComparable planning target volume (PTV) coverage was obtained with 7- and 5-beam configuration (both with 5 and 10[[ce:hsp sp="0.25"/]]mm MLC leaf-width). The comparison of bladder and rectum DVH cut-off points for the 5-beam arrangement shows that 52.6% of the plans optimized with a larger leaf-width did not satisfy at least one of the OARs’ constraints. This percentage is reduced to 10.5% for the smaller leaf-width. If a 7-beam arrangement is used the value of 52.6% decreases to 21.1% while the value of 10.5% remains unchanged.ConclusionMLCs collimators with different widths and number of leaves lead to a comparable prostate treatment planning if a proper adjustment is made of the number of gantry angles

    Facies created by the yellow coral Dendrophyllia cornigera (Lamarck, 1816): Origin, substrate preferences and habitat complexity

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    The yellow coral Dendrophyllia cornigera (Lamarck, 1816) is a NE Atlantic-Mediterranean scleractinian. It is considered a typical hard bottom species, generally reported on outcropping rocks from mesophotic to upper bathyal depths. Several evidences suggest that this species is able to tolerate a broad range of temperatures, which allows it to colonize numerous environments in a wide depth range. In the present study, we first provided a detailed ecological characterization of the D. cornigera dense aggregation thriving on the Mantice Shoal (NW Ligurian Sea, Mediterranean Sea). Information on substrate type and inclination, average extension and density, colonies size-class frequency distribution and associated fauna are reported. Then, we presented an extensive review of the available information on the ecology of this species, including 142 new ROV records from the Italian coast (40–1820 m). Results indicated that D. cornigera occurs on a wide range of substrates, including soft bottoms and hardgrounds (outcropping rocks, coralligenous rock and dead cold-water coral frameworks), with significant differences in colony density and size among different substrates. Dendrophyllia cornigera creates three main facies, each characterized by a specific combination of substrate, inclination, depth, and associated fauna. Scattered living colonies, as well as large thanatocoenoses, display a wide geographical and bathymetric distribution. Differently, the facies represented by dense meadows on horizontal soft-bottoms results rare, being reported only from the Mantice Shoal and the Amendolara Bank (Ionian Sea). The radiocarbon age of the thanatocoenoses varies between 400 (Corsica Channel) and 13000 (Vercelli Seamount) years before present. This study highlights the wide adaptability of D. cornigera in terms of environmental settings, changing the current view on the ecology of this species and providing essential insights for the implementation of international deep-sea habitat classification schemes and conservation measures

    COVID-19 : high-resolution computed tomography findings in the first 64 patients admitted to the Hospital of Cremona, the epicentre of the pandemic in Europe

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    Purpose: In December 2019, a new coronavirus (SARS-CoV-2) was identified as being responsible for the pulmonary infection called COVID-19. On 21 February 2020, the first autochthonous case of COVID-19 was detected in Italy. Our goal is to report the most common chest computed tomography (CT) findings identified in 64 patients, in the initial phase of COVID-19. Methods: Sixty-four chest high-resolution computed tomography (HRCT) examinations performed at the Radiology Unit of the Hospital of Cremona, from 22 to 29 February 2020, of 64 patients during first week of hospitalization for COVID-19 were retrospectively evaluated. All cases were confirmed by real-time RT-PCR for SARS-CoV-2. Image analysis was independently conducted by 2 radiologists with 10 years and 1 year of experience in chest imaging. The inter-observer agreement was obtained by applying a Cohen’s Îș test. Results: The average age of patients was 67.1 years (± 12.2); men 42 (66%). HRCT was performed on the 5th (± 1.5) day of hospitalization. More frequently, the initial CT changes of the lung show more or less extensive areas of ground-glass, as single pattern or with parenchymal consolidations. Coronavirus lung involvement appears very frequently multi-lobar, bilateral, and it concerns both subpleural and central regions. An excellent agreement (Îș: 0.88-1, CI: 0.79-1.01, p < 0.05) concerning CT findings between the 2 operators was reached. Conclusions: Our data suggest that detection of the most frequent pulmonary CT-scan changes, in the early stages of COVID-19, can be performed, with excellent agreement, among readers with different experience, and consequently attribute their exact diagnostic value, in an appropriate clinical and environmental exposure setting

    . Ecological role and phylogenetic position of a new habitat-forming species (Canalipalpata, Sabellidae) from the Mediterranean mesophotic soft-bottoms

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    This study presents a description of Bispira riccardi sp. nov., a new habitat-forming sabellid polychaete from the mesophotic NW Mediterranean Sea. Individuals, up to 20 cm long, show a peculiar morphology of radioles, thoracic uncini, companion chaetae and ventral shield of the collar. The phylogenetic position of this new taxon in the genus Bispira has been validated using nuclear (18S rRNA) and mitochondrial (COI) markers. Aggregations of B. riccardi sp. nov. were found by ROV on horizontal muddy bottoms between 56 and 85 m, in areas subjected to high trophic inputs. Patches are fragmented and dense (up to 943 individuals m 2) probably accounting for various hectares. A 5-days continuous monitoring, carried out using an autonomous lander, revealed that the contraction of the branchial crown was positively affected by temperature and current, rapidly responding to meteorological events. The filtering activity and high density of these fields suggest a considerable impact on the pelagic-benthic coupling and the amount of organic matter in the sediments. Indeed, meiofaunal abundance and diversity within the aggregations resulted significantly higher than in outer stations. These findings highlight the undisclosed potential of the deep Mediterranean Sea for sabellid diversity and their importance as habitat-forming species on mesophotic soft bottoms

    Serotonin transporter (SERT) and translocator protein (TSPO) expression in the obese ob/ob mouse

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    Background: An ever growing body of evidences is emerging concerning metabolism hormones, neurotransmitters or stress-related biomarkers as effective modulators of eating behavior and body weight in mammals. The present study sought at examining the density and affinity of two proteins related to neurotransmission and cell metabolism, the serotonin transporter SERT and the cholesterol import-benzodiazepine site TSPO (translocator protein), in a rodent leptin-lacking mutant, the obese ob/ob mouse. Binding studies were thus carried out in brain or peripheral tissues, blood platelets (SERT) and kidneys (TSPO), of ob/ob and WT mice supplied with a standard diet, using the selective radiochemical ligands [(3)H]-paroxetine and [(3)H]-PK11195. Results: We observed comparable SERT number or affinity in brain and platelets of ob/ob and WT mice, whilst a significantly higher [(3)H]-PK11195 density was reported in the brain of ob/ob animals. TSPO binding parameters were similar in the kidneys of all tested mice. By [(3)H]-PK11195 autoradiography of coronal hypothalamic-hippocampal sections, an increased TSPO signal was detected in the dentate gyrus (hippocampus) and choroids plexus of ob/ob mice, without appreciable changes in the cortex or hypothalamic-thalamic regions. Conclusions: These findings show that TSPO expression is up-regulated in cerebral regions of ob/ob leptin-deficient mice, suggesting a role of the translocator protein in leptin-dependent CNS trophism and metabolism. Unchanged SERT in mutant mice is discussed herein in the context of previous literature as the forerunner to a deeper biochemical investigation

    New records of rare species in the Mediterranean Sea (October 2020)

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    This Collective Article presents information about 21 taxa belonging to seven Phyla (one Ochrophyta, one Porifera, three Cnidaria, two Arthropoda, three Mollusca, one Echinodermata, and ten Chordata) and extending from the western Mediterranean Sea to the Levantine Sea. The new records were reported from nine countries as follows: Spain: first records of three deep-sea species from the Blanes Canyon along the Catalan margin, namely the gorgonian Placogorgia coronata, the bivalve Acesta excavata, and the Azores rockling Gaidropsarus granti; Italy: first record of the mesopsammic nudibranch Embletonia pulchra from Ligurian shallow-waters; first record of the deep-sea carnivorous sponge Lycopodina hypogea from the north-central Tyrrhenian Sea, living in dense clusters over dead black corals; new records of the Portuguese man o’ war Physalia physalis from Sardinian and Sicilian waters; first Italian record of the large asteroid Coronaster briareus from the Ionian Sea; first record of the white grouper Epinephelus aeneus in the northernmost point of the Adriatic Sea; Croatia: first record of the gastropod Haliotis mykonosensis for the Adriatic Sea; Malta: new sightings of Physalia physalis from Maltese waters; Libya: first record of the sand crab Albunea carabus from two localities along the Libyan coast; Greece: first records of the deep-sea black coral Parantipathes larix from the eastern Mediterranean Sea; first verified record of the agujon needlefish Tylosurus imperialis in the Hellenic Ionian Sea; first confirmed record of the brown algae Treptacantha squarrosa in the eastern Mediterranean Sea; new records of three deep-sea fish species from the Aegean Sea, namely the bluntnose sixgill shark Hexanchus griseus, the Atlantic pomfret Brama brama, and the rudderfish Centrolophus niger; new record of the tripletail Lobotes surinamensis from Lesvos Island; new record of the shrimp Brachycarpus biunguiculatus from the gut content of the non-indigenous lionfish Pterois miles; Turkey: new record of the imperi- al blackfish Schedophilus ovalis from Turkish waters; Lebanon: first record of the slender sunfish Ranzania laevis, stranded along the Lebanese coast; Israel: new record, after about 60 years from the last catch, of the spotted dragonet Callionymus maculatus.peer-reviewe

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
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