100 research outputs found

    Scaling relations and baryonic cycling in local star-forming galaxies: I. The sample

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    Metallicity and gas content are intimately related in the baryonic exchange cycle of galaxies, and galaxy evolution scenarios can be constrained by quantifying this relation. To this end, we have compiled a sample of ~400 galaxies in the Local Universe, dubbed "MAGMA" (Metallicity And Gas for Mass Assembly), which covers an unprecedented range in parameter space, spanning more than 5 orders of magnitude in stellar mass (Mstar), star-formation rate (SFR), and gas mass (Mgas), and a factor of ~60 in metallicity [Z, 12+log(O/H)]. Stellar masses and SFRs have been recalculated for all the galaxies using IRAC, WISE and GALEX photometry, and 12+log(O/H) has been transformed, where necessary, to a common metallicity calibration. To assess the true dimensionality of the data, we have applied multi-dimensional principal component analyses (PCAs) to our sample. In confirmation of previous work, we find that even with the vast parameter space covered by MAGMA, the relations between Mstar, SFR, Z and Mgas (MHI+MH2) require only two dimensions to describe the hypersurface. To accommodate the curvature in the Mstar-Z relation, we have applied a piecewise 3D PCA that successfully predicts observed 12+log(O/H) to an accuracy of ~0.1dex. MAGMA is a representative sample of isolated star-forming galaxies in the Local Universe, and can be used as a benchmark for cosmological simulations and to calibrate evolutionary trends with redshift.Comment: 21 pages, 12 figures. Accepted for publication in A&A. Sample and results improved compared to previous versions. Some analysis has been removed and will be expanded in future paper

    Metronomic capecitabine as second-line treatment for hepatocellular carcinoma after sorafenib discontinuation

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    Purpose: Metronomic capecitabine (MC) is a well-tolerated systemic treatment showing promising results in one retrospective study, as second-line therapy after sorafenib failure, in patients with hepatocellular carcinoma (HCC). Methods: 117 patients undergoing MC were compared to 112 patients, eligible for this treatment, but undergoing best supportive care (BSC) after sorafenib discontinuation for toxicity or HCC progression. The two groups were compared for demographic and clinical features. A multivariate regression analysis was conducted to detect independent prognostic factors. To balance confounding factors between the two groups, a propensity score model based on independent prognosticators (performance status, neoplastic thrombosis, causes of sorafenib discontinuation and pre-sorafenib treatment) was performed. Results: Patients undergoing MC showed better performance status, lower tumor burden, lower prevalence of portal vein thrombosis, and better cancer stage. Median (95% CI) post-sorafenib survival (PSS) was longer in MC than in BSC patients [9.5 (7.5\u201311.6) vs 5.0 (4.2\u20135.7) months (p < 0.001)]. Neoplastic thrombosis, cause of sorafenib discontinuation, pre-sorafenib treatment and MC were independent prognosticators. The benefit of capecitabine was confirmed in patients after matching with propensity score [PSS: 9.9 (6.8\u201312.9) vs. 5.8 (4.8\u20136.8) months, (p = 0.001)]. MC lowered the mortality risk by about 40%. MC achieved better results in patients who stopped sorafenib for adverse events than in those who progressed during it [PSS: 17.3 (10.5\u201324.1) vs. 7.8 (5.2\u201310.1) months, (p = 0.035)]. Treatment toxicity was low and easily manageable with dose modulation. Conclusions: MC may be an efficient and safe second-line systemic therapy for HCC patients who discontinued sorafenib for toxicity or tumor progression

    Clinical, Pathological and Prognostic Features of Rare BRAF Mutations in Metastatic Colorectal Cancer (mCRC): A Bi-Institutional Retrospective Analysis (REBUS Study)

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    Simple SummarySomatic BRAF mutations occur in approximately 10% of metastatic colorectal cancers (mCRCs) and, according to the involved codon, are classified as V600E and in non-V600, accounting for 80% and 20%, respectively. Being the most frequent mutation, the BRAF V600E mutation has been extensively investigated and up to now its clinical, pathological and molecular phenotype and its prognostic impact have been clearly described. On the contrary, evidence concerning BRAF non-V600 is weaker. We retrospectively evaluated 537 mCRC patients treated at two Italian Institutions. This study corroborates and strengthens available evidence concerning phenotype and prognostic performance of BRAF non-V600 compared to BRAF V600E and BRAF wild-type mCRCs. This deeper insight on rare BRAF non-V600 mutated mCRC is a primary issue in the precision oncology era, since the wider application of NGS is expected to increase the identification of those aberrations.Recently, retrospective analysis began to shed light on metastatic colorectal cancers (mCRCs) harboring rare BRAF non-V600 mutations, documenting a distinct phenotype and a favorable prognosis. This study aimed to confirm features and prognosis of rare BRAF non-V600 mCRCs compared to BRAF V600E and BRAF wild-type mCRCs treated at two Italian Institutions. Overall, 537 cases were retrospectively evaluated: 221 RAS/BRAF wild-type, 261 RAS mutated, 46 BRAF V600E and 9 BRAF non-V600. Compared to BRAF V600E mCRC, BRAF non-V600 mCRC were more frequently left-sided, had a lower tumor burden and displayed a lower grade and an MMR proficient/MSS status. In addition, non-V600 mCRC patients underwent more frequently to resection of metastases with radical intent. Median overall survival (mOS) was significantly longer in the non-V600 compared to the V600E group. At multivariate analysis, only age < 65 years and ECOG PS 0 were identified as independent predictors of better OS. BRAF V600E mCRCs showed a statistically significant worse mOS when compared to BRAF wild-type mCRCs, whereas no significant difference was observed between BRAF non-V600 and BRAF wild-type mCRCs. Our study corroborates available evidence concerning incidence, clinicopathologic characteristics and prognosis of BRAF-mutated mCRCs

    A systematic variation of the stellar initial mass function in early-type galaxies

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    Much of our knowledge of galaxies comes from analysing the radiation emitted by their stars. It depends on the stellar initial mass function (IMF) describing the distribution of stellar masses when the population formed. Consequently knowledge of the IMF is critical to virtually every aspect of galaxy evolution. More than half a century after the first IMF determination, no consensus has emerged on whether it is universal in different galaxies. Previous studies indicated that the IMF and the dark matter fraction in galaxy centres cannot be both universal, but they could not break the degeneracy between the two effects. Only recently indications were found that massive elliptical galaxies may not have the same IMF as our Milky Way. Here we report unambiguous evidence for a strong systematic variation of the IMF in early-type galaxies as a function of their stellar mass-to-light ratio, producing differences up to a factor of three in mass. This was inferred from detailed dynamical models of the two-dimensional stellar kinematics for the large Atlas3D representative sample of nearby early-type galaxies spanning two orders of magnitude in stellar mass. Our finding indicates that the IMF depends intimately on a galaxy's formation history.Comment: 4 pages, 2 figures, LaTeX. Accepted for publication as a Nature Letter. More information about our Atlas3D project is available at http://purl.org/atlas3

    Identification of spatially-resolved markers of malignant transformation in Intraductal Papillary Mucinous Neoplasms

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    The existing Intraductal Papillary Mucinous Neoplasm (IPMN) risk stratification relies on clinical and histological factors, resulting in inaccuracies and leading to suboptimal treatment. This is due to the lack of appropriate molecular markers that can guide patients toward the best therapeutic options. Here, we assess and confirm subtype-specific markers for IPMN across two independent cohorts of patients using two Spatial Transcriptomics (ST) technologies. Specifically, we identify HOXB3 and ZNF117 as markers for Low-Grade Dysplasia, SPDEF and gastric neck cell markers in borderline cases, and NKX6-2 and gastric isthmus cell markers in High-Grade-Dysplasia Gastric IPMN, highlighting the role of TNFα and MYC activation in IPMN progression and the role of NKX6-2 in the specific Gastric IPMN progression. In conclusion, our work provides a step forward in understanding the gene expression landscapes of IPMN and the critical transcriptional networks related to PDAC progression

    Direct-acting antivirals and hepatocellular carcinoma in chronic hepatitis C: A few lights and many shadows

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    With the introduction of direct-acting antiviral agents (DAA), the rate of sustained virological response (SVR) in the treatment of hepatitis C virus (HCV) has radically improved to over 95%. Robust scientific evidence supports a beneficial role of SVR after interferon therapy in the progression of cirrhosis, resulting in a decreased incidence of hepatocellular carcinoma (HCC). However, a debate on the impact of DAAs on the development of HCC is ongoing. This review aimed to analyse the scientific literature regarding the risk of HCC in terms of its recurrence and occurrence after the use of DAAs to eradicate HCV infection. Among 11 studies examining HCC occurrence, the de novo incidence rate ranged from 0 to 7.4% (maximum follow-up: 18 mo). Among 18 studies regarding HCC recurrence, the rate ranged from 0 to 54.4% (maximum "not well-defined" followup: 32 mo). This review highlights the major difficulties in interpreting data and reconciling the results of the included studies. These difficulties include heterogeneous cohorts, potential misclassifications of HCC prior to DAA therapy, the absence of an adequate control group, short follow-up times and different kinds of follow-up. Moreover, no clinical feature-based scoring system accounts for the molecular characteristics and pathobiology of the tumours. Nonetheless, this review does not suggest that there is a higher rate of de novo HCC occurrence or recurrence after DAA therapy in patients with previous HCV infection. \ua9 2018 The Author(s). Published by Baishideng Publishing Group Inc. All rights reserved

    Laser ablation is superior to TACE in large-sized hepatocellular carcinoma: A pilot case-control study

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    Background:Limited therapies are available for large ( 6540 mm) unresectable hepatocellular carcinoma (HCC). Currently, the standard treatment with transarterial chemoembolisation (TACE) is unsatisfactory with high recurrence rate and limited effect on survival. Laser Ablation (LA) has emerged as a relatively new technique characterized by high efficacy and good safety. This study is aimed to evaluate the efficacy of LA in comparison to TACE in patients with large HCC. Methods: Eighty-two patients with a single HCC nodule 6540 mm (BCLC stage A or B) were enrolled in this case-control study. Forty-one patients were treated with LA and 41 patients were treated with TACE. Response to therapy was evaluated according to the mRECIST criteria. Survival was calculated with Kaplan-Meier from the time of cancer diagnosis to death with values censored at the date of the last follow-up. Results: Twenty-six (63.4%) and 8 (19.5%) patients had a complete response after LA and TACE, respectively (p < 0.001). Subsequently we stratified the HCCs in 3 categories according to the nodule size: 40-50 mm, 51-60 mm, and > 60 mm. LA resulted superior to TACE especially in nodules ranging between 51 and 60 mm in diameter, with a complete response rate post-LA and post-TACE of 75% and 14.3%, respectively (p = 0.0133). The 36 months cumulative survival rate in patients treated with LA and TACE was 55.4% and 48.8%, respectively. The disease recurrence rates after LA and TACE were 19.5% and 75.0%, respectively. Conclusions: LA is a more effective therapeutic option than TACE in patients with solitary large HCC

    Towards a Muon Collider

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    A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work.Comment: 118 pages, 103 figure

    Towards a muon collider

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    A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work
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