527 research outputs found

    Comparison of MODIS and ETA profiles of atmospheric parameters in coastal zones with radiosonde data

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    The quality of atmospheric profiles gathered by the spaceborne Moderate Resolution Imaging Spectroradiometer (MODIS) sensor onboard the Terra platform and those predicted by the ETA atmospheric circulation model are assessed against corresponding radiosonde (RS)measurements. The analysis is carried out on a statistical basis taking as reference the radiosoundings collected at two coastal stations, namely Ajaccio (France) and Pratica di Mare (Italy), during the spring 2000. The examined days were characterized by smooth and slow variations of the atmospheric conditions so that a temporal lag up to about three hours between RS and MODIS profiles could be considered for comparison purposes. Both ETA predictions and MODIS retrievals compare well with RS data and their relative agreement is good. Although, as expected, the profiles of the analyzed quantities, namely temperature and moisture for both MODIS and ETA outputs and horizontal wind components predicted by ETA model, could not follow the largest fluctuations measured by RS, their averages are reproduced with a satisfactory degree of reliability. These results encourage the perspective to exploit remote measurements from the MODIS sensor of atmospheric temperature and water vapour as input to operative circulation models, such as ETA, for reliable forecasts and detailed monitoring on global scale of the atmospheric structure and dynamics

    A theoretical-experimental framework for the analysis of the dynamic response of a QEPAS tuning fork device immersed in a fluid medium

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    Quartz-enhanced photoacoustic spectroscopy (QEPAS) is a trace gas sensing technique that employs a designed high-quality factor quartz tuning fork (QTF) as acousto-electric transducer. The first in-plane skew-symmetric flexural mode of the QTF is excited when weak resonant sound waves are generated between the QTF prongs. Thus, the performance of a QEPAS sensor strongly depends on the resonance properties of the QTF, namely the determination of flexural eigenfrequencies and air damping loss. In this work, we present a mixed theoretical-experimental framework to study the dynamic response of a QTF while vibrating in a fluid environment. Due to the system linearity, the dynamic response of the resonator immersed in a fluid medium is obtained by employing a Boundary Element formulation based on an ad hoc calculated Green's function. In particular, the QTF is modelled as constituted by a pair of two Euler-Bernoulli cantilevers partially coupled by a distributed linear spring. As for the forces exerted by the fluid on QTF structure, the fluid inertia and viscosity as well as an additional diffusivity term, whose influence is crucial for the correct evaluation of the system response, have been taken into account. By corroborating the theoretical analysis with the experimental outcomes obtained by means of a vibro-acoustic setup, the fluid response coefficients and the dynamics of the QTF immersed in a fluid environment are fully determined

    Effect of process conditions on the performance of a dual-reactor biodesulfurization process

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    The biotechnological gas desulfurization process under haloalkaline conditions is widely applied for removal of toxic H2S from sour gas streams. In this process H2S is biologically oxidized into elemental sulfur. Recently, the process has been extended with an anaerobic process step (dual-reactor line-up), increasing the selectivity for elemental sulfur (S8) from ~85–97% and decreasing the formation of (thio)sulfate. It was also found that biological sulfide uptake took place in the anaerobic bioreactor. In order to apply this process in industry, more insight is needed of the effect of the process conditions on the process performance. The effect of the process conditions HRT and sulfide concentration in the anaerobic bioreactor and pH on the overall product selectivities and on biological sulfide uptake in the anaerobic bioreactor were investigated. 7 experiments were performed in a pilot-scale biodesulfurization set-up. In all experiments, high selectivities (>95%) for S8 formation were obtained, except when the pH in the aerated bioreactor was increased from 8.5 to 9.1 (selectivity of 88%). Furthermore, biological sulfide uptake in the anaerobic bioreactor increased at higher sulfide concentrations and at higher pH. We hypothesize the biological sulfide uptake under anaerobic conditions is related to polysulfide formation. Our results increase the understanding how to control biological sulfide conversion in the dual-reactor biodesulfurization process

    Distribution Systems as Catalysts for Energy Transition Embedding Flexibility in Large-Scale Applications

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    Reaching the European climate target is a complex and multifaceted challenge that involves different sectors and requires coordinated efforts at various levels. Increasing the share of renewable energy sources in the energy mix and the electrification of final energy uses in all sectors represent viable solutions for the energy transition. Distribution networks are expected to be strongly influenced by and influence such transformation while withstanding progressively increasing climate impacts, and this will require a revolution at the Power System level, starting from the planning phase. The future roadmap of a power distribution system shall include not exclusively network upgrades but also non-network solutions focusing on operation strategies exploiting the flexibility gathered from distributed energy resources. To design new transition-ready planning tools for distribution systems able to consider these aspects, the role of flexibility has been analyzed on a real-world, large-scale test case characterized by a high number of connection requests and an expected high yearly electrification rate. Stress has been put on correctly assessing the value of flexibility in planning the distribution system development. One of the most important findings is that flexibility can be a valid option in helping grid management but, most importantly, an opportunity to reconsider planning by applying a new revolutionary risk-oriented approach that may lead to modify the way distribution grids have been planned and operated so far. This emerges as the disruptive value of local flexibility utilization, besides the engagement of all players, that is necessary for the completion of the energy transition

    Towards a Greener and Scalable Synthesis of Na2_{2}Ti6_{6}O13_{13} Nanorods and Their Application as Anodes in Batteries for Grid-Level Energy Storage

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    Grid applications require high power density (for frequency regulation, load leveling, and renewable energy integration), achievable by combining multiple batteries in a system without strict high capacity requirements. For these applications however, safety, cost efficiency, and the lifespan of electrode materials are crucial. Titanates, safe and longevous anode materials providing much lower energy density than graphite, are excellent candidates for this application. The innovative molten salt synthesis approach proposed in this work provides exceptionally pure Na2_{2}Ti6_{6}O13_{13} nanorods generated at 900–1100 °C in a yield ≥80 wt%. It is fast, cost‐efficient, and suitable for industrial upscaling. Electrochemical tests reveal stable performance providing capacities of ≈100 mA h g1^{-1} (Li) and 40 mA h g1^{-1} (Na). Increasing the synthesis temperature to 1100 °C leads to a capacity decrease, most likely resulting from 1) the morphology/volume change with the synthesis temperature and 2) distortion of the Na2_{2}Ti6_{6}O13_{13} tunnel structure indicated by electron energy‐loss and Raman spectroscopy. The suitability of pristine Na2_{2}Ti6_{6}O13_{13} as the anode for grid‐level energy storage systems has been proven a priori, without any performance‐boosting treatment, indicating considerable application potential especially due to the high yield and low cost of the synthesis route

    Putative role of circulating human papillomavirus DNA in the development of primary squamous cell carcinoma of the middle rectum: A case report

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    Here we present the case of a patient affected by rectal squamous cell carcinoma in which we demonstrated the presence of Human Papillomavirus (HPV) by a variety of techniques. Collectively, the virus was detected not only in the tumor but also in some regional lymph nodes and in non-neoplastic mucosa of the upper tract of large bowel. By contrast, it was not identifiable in its common sites of entry, namely oral and ano-genital region. We also found HPV DNA in the plasma-derived exosome. Next, by in vitro studies, we confirmed the capability of HPV DNA-positive exosomes, isolated from the supernatant of a HPV DNA positive cell line (CaSki), to transfer its DNA to human colon cancer and normal cell lines. In the stroma nearby the tumor mass we were able to demonstrate the presence of virus DNA in the stromal compartment, supporting its potential to be transferred from epithelial cells to the stromal ones. Thus, this case report favors the notion that human papillomavirus DNA can be vehiculated by exosomes in the blood of neoplastic patients and that it can be transferred, at least in vitro, to normal and neoplastic cells. Furthermore, we showed the presence of viral DNA and RNA in pluripotent stem cells of non-tumor tissue, suggesting that after viral integration (as demonstrated by p16 and RNA in situ hybridization positivity), stem cells might have been activated into cancer stem cells inducing neoplastic transformation of normal tissue through the inactivation of p53, p21, and Rb. It is conceivable that the virus has elicited its oncogenic effect in this specific site and not elsewhere, despite its wide anatomical distribution in the patient, for a local condition of immune suppression, as demonstrated by the increase of T-regulatory (CD4/CD25/FOXP3 positive) and T-exhausted (CD8/PD-1positive) lymphocytes and the M2 polarization (high CD163/CD68 ratio) of macrophages in the neoplastic microenvironment. It is noteworthy that our findings depicted a static picture of a long-lasting dynamic process that might evolve in the development of tumors in other anatomical sites

    Beta-Catenin/HuR Post-Transcriptional Machinery Governs Cancer Stem Cell Features in Response to Hypoxia

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    Hypoxia has been long-time acknowledged as major cancer-promoting microenvironment. In such an energy-restrictive condition, post-transcriptional mechanisms gain importance over the energy-expensive gene transcription machinery. Here we show that the onset of hypoxia-induced cancer stem cell features requires the beta-catenin-dependent post-transcriptional up-regulation of CA9 and SNAI2 gene expression. In response to hypoxia, beta-catenin moves from the plasma membrane to the cytoplasm where it binds and stabilizes SNAI2 and CA9 mRNAs, in cooperation with the mRNA stabilizing protein HuR. We also provide evidence that the post-transcriptional activity of cytoplasmic beta-catenin operates under normoxia in basal-like/triple-negative breast cancer cells, where the beta-catenin knockdown suppresses the stem cell phenotype in vitro and tumor growth in vivo. In such cells, we unravel the generalized involvement of the beta-catenin-driven machinery in the stabilization of EGF-induced mRNAs, including the cancer stem cell regulator IL6. Our study highlights the crucial role of post-transcriptional mechanisms in the maintenance/acquisition of cancer stem cell features and suggests that the hindrance of cytoplasmic beta-catenin function may represent an unprecedented strategy for targeting breast cancer stem/basal-like cells

    Strategies and Alliances into Action to Improve National Collaboration

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    The Italian NILDE network of libraries continues to grow through the use of the NILDE system and currently comprises more than 600 Italian librarians and about 10.000 registered end-users.The system allows to daily manage and to record all the Inter-Library-Loan (ILL) operations, with a high national coverage. This paper presents the NILDE network governance and evolution and the strategies that have been put into action to improve collaboration in resource sharing among the participants. These strategies include: − release of best practices and worst practices; − activities to promote the knowledge about the network; − cooperation with the Italian national catalogs and consortia; − data analysis about ILL and its performance, related to: turn around time, reciprocity factor, requested/supplied documents imbalance analysis, analysis of ILL requested serial titles and their relationship with consortial e-only acquisitions. The availability of such a high volume of ILL data has allowed for the first time to analyze the trends and gaps of ILL and to help future cooperative acquisitions planning

    BIOF\u2013HILO assay: A new MALDI\u2013TOF mass spectrometry based method for discriminating between high-and low-biofilm-producing candida parapsilosis isolates

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    Candida parapsilosis is the most frequent cause of catheter-related candidemia among non-Candida albicans species. This may be related to intrinsic capabilities as adhering and forming a biofilm on abiotic surfaces such as on medical devices. As previously demonstrated, patients infected with high biofilm-producing C. parapsilosis isolates had a greater mortality risk compared to patients infected with low biofilm-producing C. parapsilosis isolates. We developed the BIOF\u2013HILO assay, a MALDI\u2013TOF mass spectrometry (MS)-based assay, which compares mass spectra obtained from attached and suspended isolate cells during the early (i.e., 3-h) adhesion phase of in vitro biofilm formation. The composite correlation index (CCI) analysis was used to discriminate between mass spectra differences of the two cell types, classifying all 50 C. parapsilosis clinical isolates, included in the study, after only 3-h of testing, in high or low biofilm producers. All high (n = 25) or low (n = 25) biofilm producers had, according to CCI mass spectra comparison values, higher or lower than one CCI ratios, which were obtained by dividing the CCIsuspendedcells by the CCIattachedcells . In conclusion, the BIOF\u2013HILO assay allows a rapid categorization of C. parapsilosis clinical isolates in high or low biofilm producers. This information, if timely provided to physicians, may improve treatment outcomes in patients with C. parapsilosis candidemia
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