531 research outputs found

    Tumor-on-a-chip platforms to study cancer-immune system crosstalk in the era of immunotherapy

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    Immunotherapy is a powerful therapeutic approach able to re-educate the immune system to fight cancer. A key player in this process is the tumor microenvironment (TME), which is a dynamic entity characterized by a complex array of tumor and stromal cells as well as immune cell populations trafficking to the tumor site through the endothelial barrier. Recapitulating these multifaceted dynamics is critical for studying the intimate interactions between cancer and the immune system and to assess the efficacy of emerging immunotherapies, such as immune checkpoint inhibitors (ICIs) and adoptive cell-based products. Microfluidic devices offer a unique technological approach to build tumor-on-a-chip reproducing the multiple layers of complexity of cancer-immune system crosstalk. Here, we seek to review the most important biological and engineering developments of microfluidic platforms for studying cancer-immune system interactions, in both solid and hematological tumors, highlighting the role of the vascular component in immune trafficking. Emphasis is given to image processing and related algorithms for real-time monitoring and quantitative evaluation of the cellular response to microenvironmental dynamic changes. The described approaches represent a valuable tool for preclinical evaluation of immunotherapeutic strategies

    Proximity effect in planar superconducting tunnel junctions containing Nb/NiCu superconductor/ferromagnet bilayers

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    We present experimental results concerning both the fabrication and characterization of superconducting tunnel junctions containing superconductor/ferromagnet (S/F) bilayers made by niobium (S) and a weak ferromagnetic Ni0.50Cu0.50 alloy. Josephson junctions have been characterized down to T=1.4 K in terms of current-voltage I-V characteristics and Josephson critical current versus magnetic field. By means of a numerical deconvolution of the I-V data the electronic density of states on both sides of the S/F bilayer has been evaluated at low temperatures. Results have been compared with theoretical predictions from a proximity model for S/F bilayers in the dirty limit in the framework of Usadel equations for the S and F layers, respectively. The main physical parameters characterizing the proximity effect in the Nb/NiCu bilayer, such as the coherence length and the exchange field energy of the F metal, and the S/F interface parameters have been also estimated

    Livestock Wastes Sustainable Use and Management: Assessment of Raw Sheep Wool Reuse and Valorization

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    Worldwide, around 998 million tons of agricultural waste are generated yearly, including livestock wastes, which create several critical environmental issues if not properly treated. In this study, a Geographical Information System (GIS)-based model to locate and quantify both the yearly amount of livestock waste, i.e., sheep wool, and the territorial distribution of sheep farms, was carried out and applied within the selected study area. The aim was to identify those territorial areas most suitable for localizing new shared wool collection centers to sustainably manage the reuse of this waste as potential green building material. Data related to both sheep farms and sheep number and the related sheep shared wool (SSW) yearly production were acquired and applied in GIS. By GIS-based model results, two collection centers have been identified within the provinces of Agrigento and Enna. Then, to develop a sustainable reuse in terms of reducing environmental impact due to the SSW logistics and supply phase, a possible third collection center was localized within the territorial area belonging to the province of Ragusa (south area of the Sicily). In this research, for the first time the issue above reported was addressed, by achieving results that contribute at developing an efficient collection chain for recovering and properly reusing SSW to respond adequately to a further industrial scale production

    Supporting University Students During the Pandemic: A Study on The Efficacy of a Mentalizing Online Group Counselling

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    Background: University counselling services assume a fundamental support function for students who are facing moments of crisis during their academic career. Such services often aim to reduce drop-out rates and achieve improvement in terms of psychological well-being. COVID-19 contagion containment measures have also had an impact on the psychological health of university students and their ability to cope with important developmental tasks. It has become necessary, therefore, to offer online counselling services which has become, however, the means of choice to support students during the university course in the pandemic era, as a complementary intervention to the traditional face-to-face approach. Methods: In a clinical and health psychology perspective, this study aims to analyze the efficacy of 13 online counselling groups involving 66 underachieving students, lagging with their studies. The intervention has adopted the methodology of the Narrative Mediation Path, which aims at promoting mentalization, academic engagement and psychological well-being in order to have an impact on students’ academic performance and prevent university dropouts. At the beginning and end of counselling the following measures were administered: a) Reflective Functioning Questionnaire, b) Psychological General Well-Being Index Short Form, c) Academic Performance Inventory, d) University Student Engagement Inventory, e) Group Climate Questionnaire. Results: The results showed that online counselling groups enabled an overall improvement in all the variables considered. Conclusion: Overall, the present study showed the efficacy of the online group counselling service in supporting students during the pandemic period and in coping with the difficulties encountered during the academic career

    Quasiparticles energy relaxation times in NbN/CuNi nanostripes from critical velocity measurements

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    The dynamic instability of the moving vortex lattice at high driving currents in NbN/CuNi-based and NbN nanostripes designed for optical detection has been studied. By applying the model proposed by Larkin and Ovchinnikov [Zh. Eksp. Teor. Fiz. 68, 1915 (1975)], from the critical velocity v∗ for the occurrence of the instability, it was possible to estimate the values of the quasiparticle relaxation times τE. The results show that the NbN/CuNi-based devices are characterized by shorter values of τE compared to that of NbN

    Zeolite-feldspar epiclastic rocks as flux in ceramic tile manufacturing

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    Low-cost, naturally-occurring mixtures of feldspar and zeolite occurring in epiclastic rocks are promising substitutes for conventional quartz-feldspathic fluxes in ceramic bodies, since their fusibility and low hardness are expected to improve both grinding and sintering. Three epiclastic outcrops, with a different zeolite-to-feldspar ratio, were characterized (XRPD, fusibility) and tested in porcelain stoneware bodies; their behaviour during processing was appraised and compared with that of a reference. The addition of an epiclastic rock (20 wt.%), replacing rhyolite and aplite fluxes, brought about some significant advantages, mainly represented by better grindability, lower firing temperature with improved mechanical strength and lower porosity. Disadvantages concern increased slip viscosity, worse powder compressibility, resulting in larger firing shrinkage, and a darker colour of the tiles due to relatively high amounts of iron oxide

    Pulse-induced switches in a Josephson tunnel stacked device

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    Pulse activated transitions from the metastable to the running state and viceversa have been observed in a stacked double tunnel Nb-based Josephson system. Experimental results are compared with numerical simulations based on the Sine-Gordon model of the stacked junctions by injecting pulses with variable amplitude in one of the junctions of the stack, and observing the voltage response of the other junction. Both experimental and numerical results show the possibility to induce both direct and back-switching transitions from the metastable to the running state simply by changing the amplitude of the electronic pulses injected across the stack device.Comment: Submitted to Appl.Phys.Letters, May 2001 PDF format: 14 pages, 3 Figure

    Properties of HO2• radicals induced by γ-ray irradiation in silica nanoparticles

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    We report an experimental investigation on the effects of γ-ray irradiation in several types of silica nanoparticles previously loaded with O2 molecules. They differ in specific surface and average diameter. By electron paramagnetic resonance (EPR) measurements we observe the generation of about 1018 HO2•/cm3 interstitial radicals. These radicals are induced by reaction of interstitial O2 molecules with radiolytic H atoms, as previously suggested for O2-loaded bulk a-SiO2 samples. However, at variance with respect to bulk materials, our experimental evidences suggest a different generation process of HO2• radical. In fact, by a detailed study of samples exposed to D2O, our results prove that radiolytic hydrogen atoms reacting with O2 to produce HO2• mainly arise from a radiation induced breaking of H2O molecules in the layers surrounding the nanoparticles or in the interstices. Also, by the correlation of HO2• paramagnetic centers concentration, determined by EPR measurements, and O2 Raman/PL signal we further considered the issue of the direct estimation of the O2 concentration in silica nanoparticles from Raman/PL spectra giving an independent conversion factor (the ratio between these latter two quantities), which is in good agreement with those previously proposed by other authors basing on optical measurements

    Investigation of dark count rate in NbRe microstrips for single photon detection

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    Superconducting microstrip single photon detectors (SMSPDs) received great interest since they are expected to combine the excellent performance of superconducting nanostrip single photon detectors with the possibility to cover large active areas using low-cost fabrication techniques. In this work, we fabricated SMSPDs based on NbRe to investigate the role of vortices in the dark counts events in this innovative material and in devices with micrometer size. We realized devices with different layouts, namely single microstrips and pairs of parallel microstrips. The energy barriers related to the motion of single vortices or vortex-antivortex pairs, responsible of detection events, have been determined and compared with the ones of similar devices based on different materials, such as MoSi, WSi and NbN. The analysis confirms the high potential of NbRe for the realization of superconducting single photon detectors with large areas
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