665 research outputs found

    Performance Characteristics of Nano-Modified Asphalt Mixtures

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    The growing need for high quality paving materials has aroused an increasing interest in innovative reinforcing agents, such as those characterized by nanometric dimensions. The experimental study presented in this paper focused on the use in asphalt mixtures of nanoclays and multiwall carbon nanotubes as bitumen modifiers. The performance characteristics of asphalt mixtures containing these nano-sized additives and those of a reference neat mixture were compared in a wide array of temperature and loading conditions. The testing program included the assessment of linear viscoelastic characteristics, anti-rutting potential and crack propagation resistance, by means of stiffness modulus, flow number and semi-circular bending tests, respectively. Results highlighted that both types of nano-additives have the potential to improve the performance properties of neat asphalt mixtures, with nanoclays yielding a superior reinforcing actio

    ANALYSIS OF MESENCHYMAL STEM CELLS (MSCS) SECRETOME FROM MOUSE MODELS AND HUMAN PATIENTS TO CHARACTERIZE THEIR IMMUNOMODULATORY PROPERTIES: A PROTEOMIC APPROACH.

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    Mesenchymal stem cells (MSC) are multipotent progenitor cells with self-renewable capacity and the potential to differentiate into various cell types, especially of the mesodermal lineages. They have immunomodulatory properties and, in particular, when exposed to pro-inflamatory cytokines, they acquire immunosuppressive and anti-inflammatory properties due in part to an array of soluble mediators. These cells can be used for a potential therapeutic application but, until now, a thourough characterization of pro-inflammatory primed MSC secretome is still lacking, because its characterization in vivo is very difficult. So, a commonly used approach is the analysis of media conditioned (CM) by cells in culture. The aim of this investigation is the proteomic characterization of bone marrow derived cultured MSC secretome following stimulation with pro-inflammatory cytokines, using two different models: mouse and human patients. This is a fundamental step in order to clarify the mechanism of MSC activity and to design strategies to modulate their properties for rational therapy design and improvement of existing therapies. The proteomic analysis of human MSC-CM and mouse MSC-CM confirms that exposure to pro-inflammatory cytokines results in significantly higher secretion of a number of immunomodulatory and angiogenesis-related proteins by MSC from both species. Notably, 62% of the proteins identified in st hMSC-CM were also identified in st mMSC-CM, clearly highlighting the existence of a common signature in the secretome of human and mouse MSC. However, although human and mouse MSC show a similar proteomic signature in response to stimulation by pro-inflammatory cytokines, our data indicate that they may induce different biological responses. In both species, several up-regulated proteins are associated with angiogenesis, a process that requires degradation of the vascular basement membrane and remodelling of the extracellular matrix to allow endothelial cells migration and invasion into the surrounding tissue. This is possible through the action of matrix metalloproteinases (MMPs) that degrade both matrix and non-matrix proteins and have central roles. So, the balance between MMPs and their natural inhibitors, the TIMPs, is critical for extracellular matrix remodelling and angiogenesis. Using both in vitro and in vivo assays, we identified the metalloproteinase inhibitor TIMP-1 as the molecule responsible for the anti-angiogenic effects of MSC. By identifying TIMP-1 as a critical effector of the anti-inflammatory properties of MSC, and by observing its anti-angiogenic role, both in mouse and in human, we can confirm the important role of TIMP-1 as key secreted molecule targeting endothelial cells. The identification of TIMP-1 as potential effector molecule responsible for the anti \u2013angiogenic properties of MSC, both in mouse and in human, allow to confirm that MSC exert specific effect by secretion of a broad range of bioactive molecules and allow to design pre-clinical experiments and clinical trials, with the aim of exploit thei r potentially therapeutic role

    Single Particle Operators and their Correlators in Free N=4 SYM

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    We consider a set of half-BPS operators in N = 4 super Yang-Mills theory which are appropriate for describing single-particle states of superstring theory on AdS5 Ă— S5. These single-particle operators are defined to have vanishing two-point functions with all multi-trace operators and therefore correspond to admixtures of single- and multi-traces. We find explicit formulae for all single-particle operators and for their two-point function normalisation. We show that single-particle U(N) operators belong to the SU(N) subspace, thus for length greater than one they are simply the SU(N) single-particle operators. Then, we point out that at large N, as the length of the operator increases, the single-particle operator naturally interpolates between the single-trace and the S3 giant graviton. At finite N, the multi-particle basis, obtained by taking products of the single-particle operators, gives a new basis for all half-BPS states, and this new basis naturally cuts off when the length of any of the single-particle operators exceeds the number of colours. From the two-point function orthogonality we prove a multipoint orthogonality theorem which implies vanishing of all near-extremal correlators. We then compute all maximally and next-to-maximally extremal free correlators, and we discuss features of the correlators when the extremality is lowered. Finally, we describe a half-BPS projection of the operator product expansion on the multi-particle basis which provides an alternative construction of four- and higher-point functions in the free theory

    Increased expression of programmed death ligand 1 (PD-L1) in human pituitary tumors

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    PURPOSE: Subsets of pituitary tumors exhibit an aggressive clinical courses and recur despite surgery, radiation, and chemotherapy. Because modulation of the immune response through inhibition of T-cell checkpoints has led to durable clinical responses in multiple malignancies, we explored whether pituitary adenomas express immune-related biomarkers that could suggest suitability for immunotherapy. Specifically, programmed death ligand 1 (PD-L1) has emerged as a potential biomarker whose expression may portend more favorable responses to immune checkpoint blockade therapies. We thus investigated the expression of PD-L1 in pituitary adenomas. METHODS: PD-L1 RNA and protein expression were evaluated in 48 pituitary tumors, including functioning and non-functioning adenomas as well as atypical and recurrent tumors. Tumor infiltrating lymphocyte populations were also assessed by immunohistochemistry. RESULTS: Pituitary tumors express variable levels of PD-L1 transcript and protein. PD-L1 RNA and protein expression were significantly increased in functioning (growth hormone and prolactin-expressing) pituitary adenomas compared to non-functioning (null cell and silent gonadotroph) adenomas. Moreover, primary pituitary adenomas harbored higher levels of PD-L1 mRNA compared to recurrent tumors. Tumor infiltrating lymphocytes were observed in all pituitary tumors and were positively correlated with increased PD-L1 expression, particularly in the functional subtypes. CONCLUSIONS: Human pituitary adenomas harbor PD-L1 across subtypes, with significantly higher expression in functioning adenomas compared to non-functioning adenomas. This expression is accompanied by the presence of tumor infiltrating lymphocytes. These findings suggest the existence of an immune response to pituitary tumors and raise the possibility of considering checkpoint blockade immunotherapy in cases refractory to conventional management

    Successful endovascular treatment of a 13 cm abdominal aortic aneurysm. Case report

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    There is increasing evidence in the literature that endovascular aneurysm repair is the first-line approach for most of abdominal aortic aneurysms (AAAs). Furthermore aortouniiliac stent graft placement is, in high risk patients or during emergency setting, a safe procedure over the mid- and long-term period and compares well with the results of bifurcated stent grafts. We present a case of a 66 -year-old gentleman, with pneumothorax after therapeutic thoracentesis and a giant AAA, successfully treated with an aortomonoiliac stent grafting and femoro-femoral crossover bypass

    The GINGER Project and status of the ring-laser of LNGS

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    A ring-laser attached to the Earth measures the absolute angular velocity of the Earth summed to the relativistic precessions, de Sitter and Lense-Thirring. GINGER (Gyroscopes IN GEneral Relativity) is a project aiming at measuring the LenseThirring effect with a ground based detector; it is based on an array of ring-lasers. Comparing the Earth angular velocity measured by IERS and the measurement done with the GINGER array, the Lense-Thirring effect can be evaluated. Compared to the existing space experiments, GINGER provides a local measurement, not the averaged value and it is unnecessary to model the gravitational field. It is a proposal, but it is not far from being a reality. In fact the GrossRing G of the Geodesy Observatory of Wettzell has a sensitivity very close to the necessary one. G ofWettzell is part of the IERS system which provides the measure of the Length Of the DAY (LOD); G provides information on the fast component of LOD. In the last few years, a roadmap toward GINGER has been outlined. The experiment G-GranSasso, financed by the INFN Commission II, is developing instrumentations and tests along the roadmap of GINGER. In this short paper the main activities of G-GranSasso and some results will be presented. The first results of GINGERino will be reported, GINGERino is the large ring-laser installed inside LNGS and now in the commissioning phase. Ring-lasers provide as well important informations for geophysics, in particular the rotational seismology, which is an emerging field of science. GINGERino is one of the three experiments of common interest between INFN and INGV

    NON-PETROLEUM-BASED BINDERS FOR PAVING APPLICATIONS: RHEOLOGICAL AND CHEMICAL INVESTIGATION ON AGEING EFFECTS

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    The massive exploitation of non-renewable natural resources which has taken place in the last decade has led to significant global environmental concerns. In such a context, the use of non-petroleum-based binders for the construction of bound layers of flexible pavements can represent an effective solution to limit crude oil depletion. The research work presented in this paper focused on the effects of ageing on the rheological and chemical characteristics of a non-bituminous binder, indicated in the study as a “biobinder”, and a traditional neat bitumen selected as a reference material. Binders were analyzed in four ageing conditions obtained by making use of the Rolling Thin Film Oven and of the Pressure Ageing Vessel. Rheological behaviour of binders was investigated by means of oscillatory tests carried out in a wide range of temperatures and frequencies with a dynamic shear rheometer. Chemical structure was explored via Thin Layer Chromatographic analyses and Fourier Transform Infrared Spectroscopy. The experimental work demonstrated that mechanisms of ageing which are involved in biobinders completely differ from those experienced by petroleum-based binders. Concerns were expressed with respect to the applicability to non-conventional binders of currently available ageing techniques and of chemical characterization methods
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