2,092 research outputs found

    Oxidative Methanol Reforming for Hydrogen-fed HT-PEMFC: Applications in the Naval Sector

    Get PDF
    CO2 emissions from marine transport contributes to about 3% of the overall greenhouse gas (GHG) emissions. International regulations and the Paris agreement require to cut them by 50% by 2050. Moreover, the latest International Maritime Organization (IMO) regulations strongly limits SOx emissions. One of the most promising alternatives to conventional fuels is hydrogen, which can meet the environmental targets set by the international community, if coupled with H2-fed PEM fuel cells (PEMFCs) due to their high efficiency. On-board H2 production starting from a suitable liquid source can be competitive compared to compressed/liquid H2. Methanol (MeOH) is a suitable candidate due to: high H2 content, relatively low reforming temperature, absence of sulfur compounds, and the possibility of being obtained from renewable materials. This work investigates the coupling of autothermal oxidative MeOH steam reforming (OSRM) with high temperature PEMFCs (HT-PEMFCs). The latter outperforms low temperature (LT) PEMFCs, concerning resistance to CO poisoning and high operating temperature, allowing an integrated OSMR reactor – HT-PEMFC and energetically self-sustaining system. The integrated system has also been designed considering also MeOH storage tank and the main auxiliary units, and the dimensions appear very interesting for the installation on board of ships, also in terms of emissions

    RYK promotes the stemness of glioblastoma cells via the WNT/ \u3b2-catenin pathway

    Get PDF
    Glioblastoma multiforme (GBM) is characterized by a strong self-renewal potential and a poor differentiation state. Since receptor-like tyrosine kinase (RYK) activates the WNT/\u3b2-catenin pathway essential for cancer stem cell maintenance, we evaluated its contribution in conferring stemness to GBM cells. Here, we report that Ryk (related-to-receptor tyrosine kinase), an atypical tyrosine kinase receptor, is upregulated in samples from GBM patients as well as in GSCs. Ryk overexpression confers stemness properties to GBM cells through the modulation of the canonical Wnt signaling and by promoting the activation of pluripotency-related transcription factor circuitry and neurosphere formation ability. In contrast, siRNA-mediated knockdown of Ryk expression suppresses this stem-like phenotype. Rescue experiments reveal that stemness-promoting activity of Ryk is attributable, at least in part, to \u3b2-catenin stabilization. Furthermore, Ryk overexpression improves cell motility and anchorage independent cell growth. Taken together, our findings demonstrate that Ryk promotes stem cell-like and tumorigenic features to glioma cells its essential for the maintenance of GSCs and could be a target of novel therapies

    miR-340 predicts glioblastoma survival and modulates key cancer hallmarks through down-regulation of NRAS

    Get PDF
    Glioblastoma is the most common primary brain tumor in adults; with a survival rate of 12 months from diagnosis. However, a small subgroup of patients, termed long-term survivors (LTS), has a survival rate longer then 12–14 months. There is thus increasing interest in the identification of molecular signatures predicting glioblastoma prognosis and in how to improve the therapeutic approach. Here, we report miR-340 as prognostic tumor-suppressor microRNA for glioblastoma. We analyzed microRNA expression in > 500 glioblastoma patients and found that although miR-340 is strongly down-regulated in glioblastoma overall, it is up-regulated in LTS patients compared to short-term survivors (STS). Indeed, miR-340 expression predicted better prognosis in glioblastoma patients. Coherently, overexpression of miR-340 in glioblastoma cells was found to produce a tumor-suppressive activity. We identified NRAS mRNA as a critical, direct target of miR-340: in fact, miR-340 negatively influenced multiple aspects of glioblastoma tumorigenesis by down-regulating NRAS and downstream AKT and ERK pathways. Thus, we demonstrate that expression of miR-340 in glioblastoma is responsible for a strong tumor-suppressive effect in LTS patients by down-regulating NRAS. miR-340 may thus represent a novel marker for glioblastoma diagnosis and prognosis, and may be developed into a tool to improve treatment of glioblastoma

    Analysis of the chemical composition of the essential oils extracted from Lippia lacunosa Mart. & Schauer and Lippia rotundifolia Cham. (Verbenaceae) by gas chromatography and gas chromatography-mass spectrometry

    Get PDF
    Lippia lacunosa and L. rotundifolia (Verbenaceae) are two Brazilian species of complex taxonomic delimitation. The composition of the essential oils from leaves and flowers of these plants was investigated by gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS) analysis. The major components of the essential oils of flowers and leaves of L. lacunosa were: myrcene (14.7% and 11.9%), myrcenone (45.2% and 64.2%), Z-ocimenone (5.7% and 5.2%), and E-ocimenone (14.7% and 4.1%), respectively; whereas in L. rotundifolia (flowers and leaves) were a-pinene (8.7% and 1.8%), myrcene (5.1% and 3.6%), limonene (26.0% and 7.9 %), cis-pinocamphone (4.5% and 3.1%) and myrtenal (22.3% and 16.7%), respectively. The essential oils from L. lacunosa exhibited a strong and pleasant mango aroma, which was related to the presence of myrcene and myrcenone. The marked differences in the chemical composition of their essential oils may represent a powerful tool for the botanical classification.Lippia lacunosa e L. rotundifolia são duas espécies brasileiras que formam um complexo de difícil delimitação taxonômica. A composição química do óleo essencial das folhas e flores dessas plantas foi investigada por cromatografia com fase gasosa (CG) e por cromatografia com fase gasosa acoplada à espectrometria de massas (CG-EM). Principais constituintes dos óleos essenciais de L. lacunosa (flores e folhas): mirceno (14,7% e 11,9%), mircenona (45,2% e 64,2%), Z-ocimenona (5,7% e 5,2%), e E-ocimenona (14,7% e 4,1%), respectivamente; L. rotundifolia (flores e folhas): a-pineno (8,7% e 1,8%), mirceno (5,1% e 3,6%), limoneno (26,0% e 7,9 %), cis-pinocanfona (4,5% e 3,1%) e mirtenal (22,3% e 16,7%), respectivamente. Os óleos essenciais de L. lacunosa apresentaram um forte e agradável aroma de manga, que foi relacionado à presença de mirceno e mircenona. Diferenças fundamentais na composição química de seus óleos essenciais podem representar uma poderosa ferramenta na classificação botânica das espécies

    POTENCIAL ENERGÉTICO DOS RESÍDUOS DO FRUTO DA MACAÚBA E SUA UTILIZAÇÃO NA PRODUÇÃO DE CARVÃO VEGETAL

    Get PDF
    The use of biomass for energy purposes has been highlighted in as a way to reduce dependence on non-renewable energy sources. Macaw palm, Acrocomia aculeata (Jacq.) Lodd. ex Martius, is an arborescent palm and has a high energy potential from the fruit processing. The aim of this study was to characterize the macaw palm residues after the fruit processing to evaluate its use "in natura" and as charcoal. The endocarp showed higher fixed carbon content, heating value and bulk density compared with other residues and lower ashes content. The heating value of endocarp charcoal was the highest, whereas the volatile matter levels of epicarp charcoal showed higher results. All evaluated residues from the macaw palm fruit processing have potential in power generation, especially the endocarp and the epicarp. The endocarp charcoal has suitable characteristics as source of energy and as a reductant.O uso da biomassa para fins energéticos tem sido destaque como forma de reduzir a dependência energética de fontes não renováveis. A macaúba, espécie Acrocomia aculeata (Jacq.) Lodd. ex Martius, é uma palmeira arborescente. Possui um grande potencial energético a partir do processamento de seus frutos. O objetivo desse trabalho foi caracterizar os resíduos da macaúba após o processamento dos frutos, a fim de avaliar a sua utilização in natura e como carvão vegetal. O endocarpo apresentou teor de carbono fixo, poder calorífico e densidade a granel superiores, quando comparado aos demais resíduos e menores teores de cinza. O poder calorífico do carvão do endocarpo foi superior, enquanto que os teores de materiais voláteis do carvão do epicarpo apresentaram os maiores resultados. Todos os resíduos avaliados do processamento do fruto da macaúba têm potencial na geração de energia, especialmente o endocarpo e o epicarpo. O carvão do endocarpo possui características adequadas para sua utilização como fonte de energia e como redutor

    ENERGY POTENTIAL OF THE MACAW PALM FRUIT RESIDUES AND THEIR USE IN CHARCOAL PRODUCTION

    Get PDF
    O uso da biomassa para fins energ\ue9ticos tem sido destaque como forma de reduzir a depend\ueancia energ\ue9tica de fontes n\ue3o renov\ue1veis. A maca\ufaba, esp\ue9cie Acrocomia aculeata (Jacq.) Lodd. ex Martius, \ue9 uma palmeira arborescente. Possui um grande potencial energ\ue9tico a partir do processamento de seus frutos. O objetivo desse trabalho foi caracterizar os res\uedduos da maca\ufaba ap\uf3s o processamento dos frutos, a fim de avaliar a sua utiliza\ue7\ue3o in natura e como carv\ue3o vegetal. O endocarpo apresentou teor de carbono fixo, poder calor\uedfico e densidade a granel superiores, quando comparado aos demais res\uedduos e menores teores de cinza. O poder calor\uedfico do carv\ue3o do endocarpo foi superior, enquanto que os teores de materiais vol\ue1teis do carv\ue3o do epicarpo apresentaram os maiores resultados. Todos os res\uedduos avaliados do processamento do fruto da maca\ufaba t\ueam potencial na gera\ue7\ue3o de energia, especialmente o endocarpo e o epicarpo. O carv\ue3o do endocarpo possui caracter\uedsticas adequadas para sua utiliza\ue7\ue3o como fonte de energia e como redutor.The use of biomass for energy purposes has been highlighted in as a way to reduce dependence on nonrenewable energy sources. Macaw palm, Acrocomia aculeata (Jacq.) Lodd. ex Martius, is an arborescent palm and has a high energy potential from the fruit processing. The aim of this study was to characterize the macaw palm residues after the fruit processing to evaluate its use \u201cin natura\u201d and as charcoal. The endocarp showed higher fixed carbon content, heating value and bulk density compared with other residues and lower ashes content. The heating value of endocarp charcoal was the highest, whereas the volatile matter levels of epicarp charcoal showed higher results. All evaluated residues from the macaw palm fruit processing have potential in power generation, especially the endocarp and the epicarp. The endocarp charcoal has suitable characteristics as source of energy and as a reductant

    Elastodontic Therapy of Hyperdivergent Class II Patients Using AMCOP® Devices: A Retrospective Study

    Get PDF
    Background: The management of a hyperdivergent growth pattern is one of the most challenging in orthodontics and different treatments are advocated. The present study analyses the effectiveness of elastodontic therapy with AMCOP® devices in treating children with hyperdivergent class II malocclusion and the effect on the upper airway patency. Methods: The study group included 21 patients (10 males and 11 females, mean age 8.22 ± 1.17 years) with a hyperdivergent growth and a class II malocclusion treated with AMCOP® devices. Cephalometric analysis was performed before treatment (T0) and after treatment (T1). Results: After treatment, the cephalometric analysis revealed a correction of the class II malocclusion and a modification of the growth pattern with a divergence reduction. The improvement of the upper airway space was also observed. Conclusion: The elastodontic therapy effectively corrected hyperdivergent class II malocclusion in growing patients over a short period

    Campi Flegrei, Vesuvius and Ischia Seismicity in the Context of the Neapolitan Volcanic Area

    Get PDF
    Studying seismicity in a volcanic environment provides important information on the state of activity of volcanoes. The seismicity of the Neapolitan volcanoes, Campi Flegrei, Vesuvius, and Ischia, shows distinctive characteristics for each volcano, covering a wide range of patterns and types. In this study we relocated some significant volcano-tectonic earthquake swarms that occurred in Campi Flegrei and Vesuvius. Moreover, we compared the earthquake occurrence evolution, the magnitude and the seismic energy release of the three volcanoes. Also, we considered the results of seismic analysis in the light of geochemical and ground deformation data that contribute to defining the state of activity of volcanoes. In Campi Flegrei, which is experiencing a long term unrest, we identified a seismogenic structure at shallow depth in Pisciarelli zone that has been activated repeatedly. The increasing seismicity accompanies an escalation of the hydrothermal activity and a ground uplift phase. At Vesuvius a very shallow seismicity is recorded, which in recent years has shown an increase in terms of the number of events per year. Earthquakes are usually located right beneath the crater axis. They are concentrated in a volume affected by the hydrothermal system. Finally, Ischia generally shows a low level of seismicity, however, in Casamicciola area events with a moderate magnitude can occur and these are potentially capable of causing severe damage to the town and population, due to their small hypocentral depth (typically < 2.5 km). After the seismic crisis of August 21, 2017 (mainshock magnitude M = 4), the seismicity returned to a low level in terms of occurrence rate and magnitude of earthquakes. The seismicity of these three different volcanic areas shows some common aspects that highlight a relevant role of hydrothermal processes in the seismogenesis of volcanic areas. However, while the main swarms in Campi Flegrei and most of the Vesuvian earthquakes are distributed along conduit-like structures, the seismicity of Ischia is mainly located along faults. Furthermore, the temporal evolution of seismicity in Neapolitan volcanic area suggests a concomitant increase in the occurrence of earthquakes both in Campi Flegrei and Vesuvius in recent years

    Microcephaly, sensorineural deafness and Currarino triad with duplication–deletion of distal 7q

    Get PDF
    Currarino syndrome (CS) is a peculiar form of caudal regression syndrome [also known as autosomal dominant sacral agenesis (OMIM no. 176450)] characterised by (1) partial absence of the sacrum with intact first sacral vertebra, (2) a pre-sacral mass and (3) anorectal anomalies (Currarino triad). We studied a 3-year-old girl with Currarino triad who had additional systemic features and performed array comparative genomic hybridisation to look for chromosomal abnormalities. This girl had the typical spectrum of anomalies of the CS including (a) partial sacral agenesis (hemisacrum with remnants of only sacral S1–S2 vertebrae and a residual S3 vertebral body) associated with complete coccygeal agenesis, (b) pre-intrasacral dermoid, (c) intra-dural lipoma, (d) ectopic anus and (e) tethered cord. She had, in addition, pre- and post-natal growth impairment (<3rd percentile), severe microcephaly (<−3 SD) with normal gyration pattern and lack of cortical thickening associated with a hypoplastic inferior vermis, facial dysmorphism, sensorineural deafness and decreased serum levels of IGF-1. A de novo 10.3-Mb duplication of 7q34–q35 and an 8.8-Mb deletion on 7q36 were identified in this patient. The Homeobox HLXB9 (CS) gene is contained within the deletion accounting for the CS phenotype including microcephaly. The spectrums of associated abnormalities in the IGF-1 deficiency growth retardation with sensorineural deafness and mental retardation syndrome (OMIM no. 608747) are discussed. To the best of our knowledge, this is the first reported case of a patient with distal 7q chromosomal imbalance and features of CS triad (including microcephaly) and the first documented case of a patient with normal gyration pattern microcephaly. The spectrum of associated anomalies in this newly recognised phenotype complex consists of growth failure, typical facial anomalies with additional (previously unreported) nervous system abnormalities (e.g. sensorineural deafness) and somatomedin C deficiency
    corecore