2,578 research outputs found

    the reuse of abandoned acquaresi mine voids for storage of the masua flotation tailings

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    Often in abandoned mine sites are present both underground voids produced by mining and the tailings of treatment plant. An interesting solution for the rehabilitation of the sites would be to place the tailings of the process in the underground mining voids, thus obtaining the reclamation of surface areas and the stabilization of abandoned voids to prevent the dangerous phenomena of subsidence. However, these operations require inert waste, which must not be source of pollution, and the choice of a water/solid optimum to ensure good conditions of pumpability

    Application of Seismic Tomography and Geotechnical Modeling for the Solution of Two Complex Instability Cases

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    The geotechnical instability of sites and artificial structures is a widespread problem that particularly affects heavily anthropized areas and historical cities, and often this instability is linked to human activities and to interventions carried out without adequate preliminary geotechnical studies. The most common procedure for assessing unstable sites includes base studies such as drilling boreholes, shallow excavations, and engineering geology studies. However, more and more often, some geophysical techniques are associated to the above intervention, represent the first phase of assessment, and allow optimizing the possible campaign of excavations and boreholes. Compared to direct surveys, the geophysical ones provide extensive and continuous information, are moderately invasive, and have a remarkably advantageous information-to-cost ratio. In this chapter, we illustrate two examples of characterization of unstable sites. The first case concerns the ancient walls of an Italian city, and the second one deals with the instability of a road slope. In both cases, the geotechnical modeling is also based on the results of preliminary geophysical surveys

    The Relative effectiveness of 2-Methoxyestradiol on undifferentiated and differentiated cells of glial and neuronal origin

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    INTRODUCTION: 2-Methoxyestradiol (2ME) is a well-known metabolite of 17Ī²ā€“estradiol with a high cytoxic, antimitotic and apoptotic activity. AIMS: Find differences in the relative effectiveness of 2ME on undifferentiated fast-growing and differentiated slowgrowing cells of glial and neuronal origin. MATERIALS AND METHODS: Undifferentiated glial (clone C6)/neuronal(clone C1300) cells and tapsigargin-differentiated glial/db-cAMP differentiated neuronal cells were exposed at 2ME micromolar concentrations for 5 day, observed at the contrast phase microscope and the vitality test (Hoecst 33258/propidium iodide staining)/cell proliferation rate test (MTT) were carried out. The expression of total alpha tubulin, acetylated tubulin and tyrosinated tubulin was detected by western blot. RESULTS: Undifferentiated cells ā€“ 2ME was more effective in C1300 than in C6 cells; acetylated and mainly tyrosinated alpha tubulin downregulation was more intense in C1300 cells than in C6 cells. Differentiated cells ā€“ Cells were rather resistant to 2ME; total and tyrosinated alpha tubulin expression were slightly downregulated in neuronal cells whereas acetylated tubulin was upregulated both in glial/neuronal cells. CONCLUSIONS: 2ME is more effective in neuronal than in glial cells and in undifferentiated cells in comparison whit differentiated ones. 2ME toxicity may be related to the neuronal phenotypic and metabolic patterns, to the affinity for neuronal tubulin isoforms and to the high proliferation rate of undifferentiated cells. Moreover, intense downregulation of tyrosinated tubulin showed that 2ME alters selectively the microtubular dynamics

    Numerical study of a confined slot impinging jet with nanofluids

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    <p>Abstract</p> <p>Background</p> <p>Heat transfer enhancement technology concerns with the aim of developing more efficient systems to satisfy the increasing demands of many applications in the fields of automotive, aerospace, electronic and process industry. A solution for obtaining efficient cooling systems is represented by the use of confined or unconfined impinging jets. Moreover, the possibility of increasing the thermal performances of the working fluids can be taken into account, and the introduction of nanoparticles in a base fluid can be considered.</p> <p>Results</p> <p>In this article, a numerical investigation on confined impinging slot jet working with a mixture of water and Al<sub>2</sub>O<sub>3 </sub>nanoparticles is described. The flow is turbulent and a constant temperature is applied on the impinging. A single-phase model approach has been adopted. Different geometric ratios, particle volume concentrations and Reynolds number have been considered to study the behavior of the system in terms of average and local Nusselt number, convective heat transfer coefficient and required pumping power profiles, temperature fields and stream function contours.</p> <p>Conclusions</p> <p>The dimensionless stream function contours show that the intensity and size of the vortex structures depend on the confining effects, given by <it>H/</it>W ratio, Reynolds number and particle concentrations. Furthermore, for increasing concentrations, nanofluids realize increasing fluid bulk temperature, as a result of the elevated thermal conductivity of mixtures. The local Nusselt number profiles show the highest values at the stagnation point, and the lowest at the end of the heated plate. The average Nusselt number increases for increasing particle concentrations and Reynolds numbers; moreover, the highest values are observed for <it>H/W </it>= 10, and a maximum increase of 18% is detected at a concentration equal to 6%. The required pumping power as well as Reynolds number increases and particle concentrations grow, which is almost 4.8 times greater than the values calculated in the case of base fluid.</p> <p> <b>List of symbols</b> </p

    Photophysics of pentacene-doped picene thin films

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    Here were report a study of picene nano-cristalline thin films doped with pentacene molecules. The thin films were grown by supersonic molecular beam deposition with a doping concentration that ranges between less than one molecules of pentacene every 104 picene molecules up to about one molecule of pentacene every 102 of picene. Morphology and opto-electronic properties of the films were studied as a function of the concentration of dopants. The optical response of the picene films, characterized by absorption, steady-state and time-resolved photoluminescence measurements, changes dramatically after the doping with pentacene. An efficient energy transfer from the picene host matrix to the pentacene guest molecules was observed giving rise to an intense photoluminescence coming out from pentacene. This efficient mechanism opens the possibility to exploit applications where the excitonic states of the guest component, pentacene, are of major interest such as MASER. The observed mechanism could also serve as prototypical system for the study of the photophysics of host guest systems based on different phenacenes and acenes.Comment: 15 pages, 6 figure

    High Throughput T Epitope Mapping and Vaccine Development

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    Mapping of antigenic peptide sequences from proteins of relevant pathogens recognized by T helper (Th) and by cytolytic T lymphocytes (CTL) is crucial for vaccine development. In fact, mapping of T-cell epitopes provides useful information for the design of peptide-based vaccines and of peptide libraries to monitor specific cellular immunity in protected individuals, patients and vaccinees. Nevertheless, epitope mapping is a challenging task. In fact, large panels of overlapping peptides need to be tested with lymphocytes to identify the sequences that induce a T-cell response. Since numerous peptide panels from antigenic proteins are to be screened, lymphocytes available from human subjects are a limiting factor. To overcome this limitation, high throughput (HTP) approaches based on miniaturization and automation of T-cell assays are needed. Here we consider the most recent applications of the HTP approach to T epitope mapping. The alternative or complementary use of in silico prediction and experimental epitope definition is discussed in the context of the recent literature. The currently used methods are described with special reference to the possibility of applying the HTP concept to make epitope mapping an easier procedure in terms of time, workload, reagents, cells and overall cost

    Mathematical Phase Model of Neural Populations Interaction in Modulation of REM/NREM Sleep

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    Aim of the present study is to compare the synchronization of the classical Kuramoto system and the reaction - diffusion space time Landau - Ginzburg model, in order to describe the alternation of REM (rapid eye movement) and NREM (non-rapid eye movement) sleep across the night. These types of sleep are considered as produced by the cyclic oscillation of two neuronal populations that, alternatively, promote and inhibit the REM sleep. Even if experimental data will be necessary, a possible interpretation of the results has been proposed

    Bidirectional synaptic plasticity is driven by sex neurosteroids targeting estrogen and androgen receptors in hippocampal CA1 pyramidal neurons

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    Neuroactive estrogenic and androgenic steroids influence synaptic transmission, finely modulating synaptic plasticity in several brain regions including the hippocampus. While estrogens facilitate long-term potentiation (LTP), androgens are involved in the induction of long-term depression (LTD) and depotentiation (DP) of synaptic transmission. To examine sex neurosteroid-dependent LTP and LTD in single cells, patch-clamp recordings from hippocampal CA1 pyramidal neurons of male rats and selective antagonists for estrogen receptors (ERs) and androgen (AR) receptors were used. LTP induced by high-frequency stimulation (HFS) depended on activation of ERs since it was prevented by the ER antagonist ICI 182,780 in most of the neurons. Application of the selective antagonists for ERĪ± (MPP) or ERĪ² (PHTPP) caused a reduction of the LTP amplitude, while these antagonists in combination, prevented LTP completely. LTP was never affected by blocking AR with the specific antagonist flutamide. Conversely, LTD and DP, elicited by low-frequency stimulation (LFS), were impeded by flutamide, but not by ICI 182,780, in most neurons. In few cells, LTD was even reverted to LTP by flutamide. Moreover, the combined application of both ER and AR antagonists completely prevented both LTP and LTD/DP in the same neuron. The current study demonstrates that the activation of ERs is necessary for inducing LTP in hippocampal pyramidal neurons, whereas the activation of ARs is required for LTD and DP. Moreover, both estrogen- and androgen-dependent LTP and LTD can be expressed in the same pyramidal neurons, suggesting that the activation of sex neurosteroids signaling pathways is responsible for bidirectional synaptic plasticity

    HER2 Copy Number and Resistance Mechanisms in Patients with HER2-positive Advanced Gastric Cancer Receiving Initial Trastuzumab-based Therapy in JACOB Trial

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    Resistance mechanisms; Advanced gastric cancer; TrastuzumabMecanismos de resistencia; CĆ”ncer gĆ”strico avanzado; TrastuzumabMecanismes de resistĆØncia; CĆ ncer gĆ stric avanƧat; TrastuzumabPurpose: In JACOB trial, pertuzumab added to trastuzumab-chemotherapy did not significantly improve survival of patients with HER2-positive metastatic gastric cancer, despite 3.3 months increase versus placebo. HER2 copy-number variation (CNV) and AMNESIA panel encompassing primary resistance alterations (KRAS/PIK3CA/MET mutations, KRAS/EGFR/MET amplifications) may improve patientsā€™ selection for HER2 inhibition. Experimental Design: In a post hoc analysis of JACOB on 327 samples successfully sequenced by next-generation sequencing (NGS; Oncomine Focus DNA), HER2 CNV, HER2 expression by IHC, and AMNESIA were correlated with overall response rate (ORR), progression-free survival (PFS), and overall survival (OS) by univariable/multivariable models. Results: Median HER2 CNV was 4.7 (interquartile range, 2.2ā€“16.9). HER2 CNV-high versus low using the median as cutoff was associated with longer median PFS (10.5 vs. 6.4 months; HR = 0.48; 95% confidence interval: 0.38ā€“0.62; P < 0.001) and OS (20.3 vs. 13.0 months; HR = 0.54; 0.42ā€“0.72; P < 0.001). Combining HER2 CNV and IHC improved discriminative ability, with better outcomes restricted to HER2-high/HER2 3+ subgroup. AMNESIA positivity was found in 51 (16%), with unadjusted HR = 1.35 (0.98ā€“1.86) for PFS; 1.43 (1.00ā€“2.03) for OS. In multivariable models, only HER2 CNV status remained significant for PFS (P < 0.001) and OS (P = 0.004). Higher ORR was significantly associated with IHC 3+ [61% vs. 34% in 2+; OR = 3.11 (1.89ā€“5.17)] and HER2-high [59% vs. 43% in HER2-low; OR = 1.84 (1.16ā€“2.94)], with highest OR in the top CNV quartile. These biomarkers were not associated with treatment effect of pertuzumab. Conclusions: HER2 CNV-high assessed by NGS may be associated with better ORR, PFS, and OS in a JACOB subgroup, especially if combined with HER2 3+. The negative prognostic role of AMNESIA requires further clinical validation
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