6,031 research outputs found

    Retinoic acid signaling in axonal regeneration

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    Following an acute central nervous system (CNS) injury, axonal regeneration and functional recovery are extremely limited. This is due to an extrinsic inhibitory growth environment and the lack of intrinsic growth competence. Retinoic acid (RA) signaling, essential in developmental dorsoventral patterning and specification of spinal motor neurons, has been shown through its receptor, the transcription factor RA receptor β2 (RARβ2), to induce axonal regeneration following spinal cord injury (SCI). Recently, it has been shown that in dorsal root ganglion neurons (DRGs), cAMP levels were greatly increased by lentiviral RARβ2 expression and contributed to neurite outgrowth. Moreover, RARβagonists, in cerebellar granule neurons (CGN) and in the brain in vivo, induced phosphoinositide 3-kinase dependent phosphorylation of AKT that was involved in RARβ-dependent neurite outgrowth. More recently, RA-RARβpathways were shown to directly transcriptionally repress a member of the inhibitory Nogo receptor (NgR) complex, Lingo-1, under an axonal growth inhibitory environment in vitro as well as following spinal injury in vivo. This perspective focuses on these newly discovered molecular mechanisms and future directions in the field

    The phenomenon of tools’ wear in a marble quarry: laboratory tests to evaluate the performance of conditioning as a wear preventer

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    Exploitation with a chain saw cutting machine has been the ordinary industrial practice in marble excavation for over thirty years, due to its ability to adapt to difficult environments and to guarantee a high level of safety during the cutting phase. Nevertheless, the presence of impurities in the calcite matrix, e.g. quartz, leads to the problem of rapid and unusual wear on cutting tools. In this study, two laboratory tests were selected and carried out to estimate the rock's wear potential: the CERCHAR Abrasivity test and the Soil Abrasion Test Apparatus (SATA). The results highlight a high degree of abrasivity in dry conditions, which was satisfactorily reduced by using water and additives. This mixture, typically used in tunnelling applications, is intended to decrease the wear from rock excavation and a significant reduction of this phenomenon has been noticed

    CSI-based fingerprinting for indoor localization using LTE Signals

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    Abstract This paper addresses the use of channel state information (CSI) for Long Term Evolution (LTE) signal fingerprinting localization. In particular, the paper proposes a novel CSI-based signal fingerprinting approach, where fingerprints are descriptors of the "shape" of the channel frequency response (CFR) calculated on CSI vectors, rather than direct CSI vectors. Experiments have been carried out to prove the feasibility and the effectiveness of the proposed method and to study the impact on the localization performance of (i) the bandwidth of the available LTE signal and (ii) the availability of more LTE signals transmitted by different eNodeB (cell diversity). Comparisons with other signal fingerprinting approaches, such as the ones based on received signal strength indicator or reference signal received power, clearly show that using LTE CSI, and in particular, descriptors as fingerprints, can bring relevant performance improvement

    Performance analysis of TBM excavation parameters related to small-diameter horizontal and inclined tunnels

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    Horizontal, inclined, and vertical ways through the rock are needed for several mining and civil purposes (hydropower, transportation, sewer collector, underground transports), and quite often, in the same project, horizontal, inclined, and vertical ways are necessary. These cases offer an excellent opportunity to compare the performance of excavation systems in similar geological-geomechanical environments. The basic mechanism of rock breakage, either cyclical (Drill and Blast) or continuous (TBM or Raise Borer), is the same for horizontal or inclined ways. In the latter case, the fixed motor option (Raise Borer) tends to be preferred for short, small-diameter, easily accessible top-point cases. The drill and blast system tends to be employed only in horizontal or very short inclined ways. In the first part of the paper, a general discussion of the techniques for horizontal, inclined/vertical ways excavation is provided, comparing some real cases of tunnel driving by TBM under the aspect of the machine’s average performance. The comparison of the cases makes it possible to draw some prediction criteria applicable to the TBM performance in horizontal and inclined tunnel driving

    Influence of chip-size on development of adhesion for conditioned clayey soils

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    In the excavation of clayey soil with Earth Pressure Balance TBMs, the study of soil conditioning is a complex issue. The presence of a mix of water, clay and foam, often added with polymers, makes the resultant mass a material strongly time-dependent and where the internal forces are given both by mass and surface actions. Differently from granular soils, where the time-dependence of the conditioned mass is ruled by the decay of foam, in clays one the rate of adsorption of the liquid phase of the conditioning into the clay chips cannot be neglected since strongly affects the quality of the conditioned mass in time. This paper compares the difference in the adsorption rate through the evaluation of the dynamic adhesion for different chip size. For each studied clay, different chip size distributions are obtained and tested. The difference in the development of adhesion reflects the different rate of adsorption of the liquid phase showing that the dimensions of the chips should be considered in the choice of clay conditioning parameters with reference also to the estimated time spent by the conditioned material to go through the excavation chamber and to exit from the screw conveyor

    A multi-methodological protocol to characterize PDO olive oils

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    An analytical approach including Panel Test, Isotope Ratio Mass Spectrometry (IRMS) and Nuclear Magnetic Resonance (NMR) spectroscopy was proposed to characterize Italian “Colline Pontine” PDO olive oils (40 samples) of two consecutive crop years. Our approach has evidenced the high quality of these olive oils. Only 6 of 40 olive oils samples were defined as “defective” by the official Panel Test due to the detection of negative sensory attributes. The low variability of isotopic data monitored by IRMS confirmed that the olive oil samples all came from a limited geographical area. NMR spectra did not evidence any chemical composition anomaly in the investigated samples. In order to assess the influence of harvesting year over the olive oil chemical composition, the NMR analysis was extended to other 22 olive oil samples of a third harvesting year. NMR data were submitted to two different statistical methods, namely, analysis of variance (ANOVA) and principal component analysis (PCA) allowing olive oils of three consecutive harvesting years to be grouped

    Prognostic factors influencing infectious complications after cytoreductive surgery and HIPEC. Results from a tertiary referral center

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    Background. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) showed promising results in selected patients. High morbidity restrains its wide application. The aim of this study was to report postoperative infectious complications and investigate possible correlations with preoperative nutritional status and other prognostic factors in patients with peritoneal metastases treated with CRS and HIPEC. Methods. For the study we reviewed the clinical records of all patients with peritoneal metastases from different primary cancers and treated by CRS and HIPEC in our Institution from November 2000 to December 2017. Patients were divided according to their nutritional status (SGA) in group A (well-nourished), B/C (mild or severely malnourished). Possible statistical correlations between risk factors and postoperative complications rates have been investigated by univariate and multivariate analysis. Results. Two hundred patients were selected and underwent CRS and HIPEC during the study period. Postoperative complications occurred in 44% of the patients, 35.3% in SGA-A patients and 53% in SGA-B /C patients. Cause of complications was infective in 42, non-infective in 37 and HIPEC related in 9 patients. Infectious complications occurred more frequently in SGA-B /C patients (32.6% vs. 9.8% of SGA-A patients). The most frequent sites of infection were Surgical Site Infections (SSI, 35.7%) and Central Line Associated BloodStream Infections (CLABSI, 26.2%). The most frequent isolated species was Candida (22.8%). ASA score, blood loss, performance status, PCI, large bowel resection, postoperative serum albumin levels and nutritional status correlated with higher risk for postoperative infectious complications. Conclusions. Malnourished patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy are more prone to post-operative infectious complications and adequate perioperative nutritional support should be considered, including immune-enhancing nutrition. Sequential monitoring of common sites of infection, antifungal prevention of candidiasis, and careful patient selection should be implemented to reduce complications rate

    Comparative planning and housing studies beyond taxonomy: A genealogy of the Special Programme for Rehousing (Portugal)

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    Recent European comparative studies in the fields of housing policy and spatial planning have been dominated by taxonomical and linear approaches, and by normative calls for convergence toward systems considered more ‘mature’ or ‘advanced’. In this article, we adopt a genealogical perspective and consider those cultures that are central to the shaping of policy. We set out a long-term exploration of the intersection between spatial planning and housing policy in Portugal and focus on the Special Programme for Rehousing (Programa Especial de Realojamento, PER), a programme that has had changing roles (from a financial instrument to a core component of policies of urban regeneration) in connection with political and planning cultures changing in time and space. In this way, we provide evidence of the limited capacity of taxonomic and linear approaches to describe planning and housing systems undergoing processes of change and, conversely, show the potential of genealogical research.info:eu-repo/semantics/publishedVersio

    Breastfeeding education: where are we going? A systematic review article

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    Background: UNICEF (United Nations International Children’s Emergency Fund) and WHO estimate that if all babies were breastfed for at least the first six months of their lives, the rate of morbidity and malnutrition would sig-nificantly decrease all over the world. In this view, these two organizations promoted a worldwide campaign for breastfeeding, creating the Baby Friendly Hospital Initiative (BFHI) that encourages good practices for the promotion of breastfeeding in hospitals. The aim of our study was to review the available evidence regarding the positive effects of breastfeeding, in order to suggest to most appropriate strategy to support it. Methods: The main databases including Scopus, PubMed, MEDLINE, Google scholar and Science Direct were researched to obtain the original papers related to breastfeeding education. The main terms used to literature search were "Breastfeeding education", Breastfeeding support", and “Breastfeeding healthcare policy”. The timeframe in-cluded the obtained articles was from 1980 to 2015. Results: Our analysis confirms that healthcare providers play a pivotal role in education and encouraging mothers to begin and continue breastfeeding. In this view, the adequate training of healthcare providers seems to be mandatory in order to support this practice. Moreover, adequate facilities are needed in order to promote and support breastfeeding. Conclusion: Considering the available evidence, breastfeeding should be supported among all the mothers. Based on the positive data emerging from the public awareness campaign in different Countries of the world, we strongly en-courage an accurate training for doctors and midwives and the implementation of adequate facilities in order to sup-port breastfeeding
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