3,849 research outputs found

    Arms down cone beam CT hepatic angiography: are we focusing on the wrong target?

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    We read with great interest the recent article by Dr. Gonzalez-Aguirre and colleagues entitled ‘‘Arms Down Cone Beam CT Hepatic Angiography Performance Assessment: Vascular Imaging Quality and Imaging Artefacts’’ [1]. One of the most important advantages of cone beam CT (CBCT) is the possibility to evaluate the lesion’s feeders assisting their identification and catheterization [2]. In this set, the patient’s arms positioning is crucial in order not to impair CBCT imaging. Dr. Gonzalez-Aguirre et al. had elegantly demonstrated that vessels’ visualization is independent from the patient’s arms position, allowing to perform the entire procedure without patient’s movements. This minimizes the risk of contamination and reduces procedural time. However, literature shows that the major pivotal strength of CBCT, either mono-phasic or possibly bi-phasic, is the ability to depict in intra-procedurally ‘‘occult lesions’’, not visible at pre-procedural second-line non-invasive imaging (MRI, MDCT) [3]. This ability is not just for show, but yield to some major clinical implications: the visualization of an occult nodule identifies a subset of population experiencing fast tumour growth, having consequences on the number of adjunctive treatments controlling tumour growth (adjunctive RFA, or TACE procedures) and prioritization for transplantation [4]. Moreover, bi-phasic CBCT, with its unique ability to intra-procedural permit nodule characterization, could help in patients’ reclassification and real-time TACE strategy modification [5]. In this light would be a crucial interest for the audience to know whether the CBCT acquisition with arms down does not alter the diagnostic performance of the modality and ability of lesion’s characterization, especially for those lesion localized peripherally, where the beam hardening artefacts have been shown to be significant. Finally, patient’s positioning is fundamental for CBCT imaging. By acquiring the scan with patient’s arm down, liver volume would not be located within the rotation isocentre. This could be a substantial limitation for lesion located within the left liver lobe, eventually hypertrophied, and for high BMI patients

    Drying kinetics and physico-chemical quality of mango slices

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    Mango (Mangifera indica L.) is an important tropical fruit consumed worldwide and grown in Italy only in Sicily, where the areas of the Tyrrhenian coast have proved to be suitable to produce valuable fruits. Mango fruit has a pleasant aroma and taste, which are important qualities for consumer’s sensorial acceptance. However, they are highly perishable, prone to progressive undesired changes if stored untreated, resulting in around 25% postharvest losses, which is further increased during storage and transportation. An alternative for reducing the above-mentioned undesired changes is the dehydration of the cut fruit, which reduce the fruit water activity, thereby avoiding the deteriorative process and extending the shelf-life. This study investigates the effect of dehydration at different temperatures (50, 60 and 70°C) on drying kinetics and volatile compounds of two cultivars (Keitt and Osteen) of mango fruits cultivated in Sicily. Significant losses of volatile constituents of fresh mango occurred at higher temperature, especially for the Osteen cultivar. A diffusion model including the effect of shrinkage is also proposed, which may be used to describe drying behaviour of fruits and to define the optimal drying conditions.. Experimental data of the moisture ratio during drying were well predicted by the model

    Analysis of genetic relationships among Muscat grapevines in Apulia (South Italy) by RAPD markers

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    Two hundred 10-mer primers of arbitrary nucleotide sequence were used to study the genetic relationships among Muscat grapevines in Apulia. The coefficients of similarity of these genotypes were determined with 484 polymorphic RAPD bands (profiles). The bootstrap sampling analysis revealed that the number of RAPD bands was suitable to estimate the coefficients of similarity. The pattern of aggregation among genotypes (cluster analysis, principal coordinate analysis) indicates a diversity among the Muscats in Apulia except for Moscato Reale and Moscato Canelli, which were closely related

    Regulation of ISWI chromatin remodelling activity

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    The packaging of the eukaryotic genome into chromatin facilitates the storage of the genetic information within the nucleus, but prevents the access to the underlying DNA sequences. Structural changes in chromatin are mediated by several mechanisms. Among them, ATP-dependent remodelling complexes belonging to ISWI family provides one of the best examples that eukaryotic cells evolved to finely regulate these changes. ISWI-containing complexes use the energy derived from ATP hydrolysis to rearrange nucleosomes on chromatin in order to favour specific nuclear reactions. The combination of regulatory nuclear factors associated with the ATPase subunit as well as its modulation by specific histone modifications, specializes the nuclear function of each ISWI-containing complex. Here we review the different ways by which ISWI enzymatic activity can be modulated and regulated in the nucleus of eukaryotic cells

    Testosterone Replacement Therapy: Long-Term Safety and Efficacy.

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    Recent position statements and guidelines have raised the distinction between a true and false, age-related hypogonadism (HG) or late-onset hypogonadism (LOH). The former is the consequence of congenital or acquired “organic” damage of the brain centers or of the testis. The latter is mainly secondary to age-related comorbidities and does not require testosterone (T) therapy (TTh). In addition, concerns related to cardiovascular (CV) safety have further increased the scepticism related to TTh. In this paper, we reviewed the available evidence supporting the efficacy of TTh in non-organic HG and its long term safety. A large amount of evidence has documented that sexual symptoms are the most specific correlates of T deficiency. TTh is able to improve all aspects of sexual function independent of the pathogenetic origin of the disease supporting the scientific demonstration that LOH does exist according to an “ex-juvantibus” criterion. Although the presence of metabolic derangements could mitigate the efficacy of TTh on erectile dysfunction, the positive effect of TTh on body composition and insulin sensitivity might counterbalance the lower efficacy. CV safety concerns related to TTh are essentially based on a limited number of observational and randomized controlled trials which present important methodological flaws. When HG is properly diagnosed and TTh correctly performed no CV and prostate risk have been documented

    Results from a meta-analysis of immune checkpoint inhibitors in first-line renal cancer patients: does PD-L1 matter?

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    Background: The aim of this study was to perform a literature-based meta-analysis to assess the efficacy of the novel immune checkpoint inhibitors (ICIs) in first-line metastatic renal cell carcinoma (RCC), focusing on the predictive role of PD-L1 expression. Methods: The primary outcome was overall survival, and secondary outcomes were progression-free survival (PFS) and objective response. We planned a subgroup analysis for overall survival according to PD-L1 status. Results: Five studies were included in the analysis for a total of 4063 cases. Overall survival was greater in PD-L1 positive tumours (HR = 0.49, 95% CI: 0.36\u20130.67; p < 0.001). The pooled analysis of the unselected cases showed a statistically significative improvement in PFS with the use of ICIs (HR = 0.85, 95% CI: 0.72\u20130.99; p = 0.04) and we found a greater PFS benefit (HR = 0.65, 95% CI: 0.57\u20130.74; p < 0.001) in patients with PD-L1 positive tumours. Conclusions: This study supports the efficacy of ICIs and, although a significant clinical benefit has been reported in PD-L1 negative patients, a greater efficacy of ICIs was observed in PD-L1 positive patients. More prospective randomized studies are needed to clarify the role of PDL-1 status in metastatic RCC treated with ICIs

    Self-organization, scaling and collapse in a coupled automaton model of foragers and vegetation resources with seed dispersal

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    We introduce a model of traveling agents ({\it e.g.} frugivorous animals) who feed on randomly located vegetation patches and disperse their seeds, thus modifying the spatial distribution of resources in the long term. It is assumed that the survival probability of a seed increases with the distance to the parent patch and decreases with the size of the colonized patch. In turn, the foraging agents use a deterministic strategy with memory, that makes them visit the largest possible patches accessible within minimal travelling distances. The combination of these interactions produce complex spatio-temporal patterns. If the patches have a small initial size, the vegetation total mass (biomass) increases with time and reaches a maximum corresponding to a self-organized critical state with power-law distributed patch sizes and L\'evy-like movement patterns for the foragers. However, this state collapses as the biomass sharply decreases to reach a noisy stationary regime characterized by corrections to scaling. In systems with low plant competition, the efficiency of the foraging rules leads to the formation of heterogeneous vegetation patterns with 1/fα1/f^{\alpha} frequency spectra, and contributes, rather counter-intuitively, to lower the biomass levels.Comment: 11 pages, 5 figure
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