| 21. |
- Whitesides, L., et al.
(author)
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iPTF 16asu : A Luminous, Rapidly Evolving, and High-velocity Supernova
- 2017
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In: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 851:2
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Journal article (peer-reviewed)abstract
- Wide-field surveys are discovering a growing number of rare transients whose physical origin is not yet well understood. Here we present optical and UV data and analysis of intermediate Palomar Transient Factory (iPTF) 16asu, a luminous, rapidly evolving, high-velocity, stripped-envelope supernova ( SN). With a rest-frame rise time of just four. days and a peak absolute magnitude of M-g = -20.4 mag, the light curve of iPTF 16asu is faster and more luminous than that of previous rapid transients. The spectra of iPTF 16asu show a featureless blue continuum near peak that develops into an SN Ic-BL spectrum on the decline. We show that while the late-time light curve could plausibly be powered by Ni-56 decay, the early emission requires a different energy source. Nondetections in the X-ray and radio strongly constrain the energy coupled to relativistic ejecta to be at most comparable to the class of low-luminosity gamma-ray bursts (GRBs). We suggest that the early emission may have been powered by either a rapidly spinning-down magnetar or by shock breakout in an extended envelope of a very energetic explosion. In either scenario a central engine is required, making iPTF 16asu an intriguing transition object between superluminous SNe, SNe Ic-BL, and low-luminosity GRBs.
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| 22. |
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| 23. |
- Petroni, M, et al.
(author)
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SMO-M2 mutation does not support cell-autonomous Hedgehog activity in cerebellar granule cell precursors
- 2019
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In: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9:1, s. 19623-
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Journal article (peer-reviewed)abstract
- Growth and patterning of the cerebellum is compromised if granule cell precursors do not properly expand and migrate. During embryonic and postnatal cerebellar development, the Hedgehog pathway tightly regulates granule cell progenitors to coordinate appropriate foliation and lobule formation. Indeed, granule cells impairment or defects in the Hedgehog signaling are associated with developmental, neurodegenerative and neoplastic disorders. So far, scant and inefficient cellular models have been available to study granule cell progenitors, in vitro. Here, we validated a new culture method to grow postnatal granule cell progenitors as hedgehog-dependent neurospheres with prolonged self-renewal and ability to differentiate into granule cells, under appropriate conditions. Taking advantage of this cellular model, we provide evidence that Ptch1-KO, but not the SMO-M2 mutation, supports constitutive and cell-autonomous activity of the hedgehog pathway.
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| 24. |
- Dahal, Prabin, et al.
(author)
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Competing risk events in antimalarial drug trials in uncomplicated Plasmodium falciparum malaria : a WorldWide Antimalarial Resistance Network individual participant data meta-analysis
- 2019
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In: Malaria Journal. - : BMC. - 1475-2875 .- 1475-2875. ; 18
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Journal article (peer-reviewed)abstract
- Background: Therapeutic efficacy studies in uncomplicated Plasmodium falciparum malaria are confounded by new infections, which constitute competing risk events since they can potentially preclude/pre-empt the detection of subsequent recrudescence of persistent, sub-microscopic primary infections.Methods: Antimalarial studies typically report the risk of recrudescence derived using the Kaplan-Meier (K-M) method, which considers new infections acquired during the follow-up period as censored. Cumulative Incidence Function (CIF) provides an alternative approach for handling new infections, which accounts for them as a competing risk event. The complement of the estimate derived using the K-M method (1 minus K-M), and the CIF were used to derive the risk of recrudescence at the end of the follow-up period using data from studies collated in the WorldWide Antimalarial Resistance Network data repository. Absolute differences in the failure estimates derived using these two methods were quantified. In comparative studies, the equality of two K-M curves was assessed using the log-rank test, and the equality of CIFs using Gray's k-sample test (both at 5% level of significance). Two different regression modelling strategies for recrudescence were considered: cause-specific Cox model and Fine and Gray's sub-distributional hazard model.Results: Data were available from 92 studies (233 treatment arms, 31,379 patients) conducted between 1996 and 2014. At the end of follow-up, the median absolute overestimation in the estimated risk of cumulative recrudescence by using 1 minus K-M approach was 0.04% (interquartile range (IQR): 0.00-0.27%, Range: 0.00-3.60%). The overestimation was correlated positively with the proportion of patients with recrudescence [Pearson's correlation coefficient (rho): 0.38, 95% Confidence Interval (CI) 0.30-0.46] or new infection [rho: 0.43; 95% CI 0.35-0.54]. In three study arms, the point estimates of failure were greater than 10% (the WHO threshold for withdrawing antimalarials) when the K-M method was used, but remained below 10% when using the CIF approach, but the 95% confidence interval included this threshold.Conclusions: The 1 minus K-M method resulted in a marginal overestimation of recrudescence that became increasingly pronounced as antimalarial efficacy declined, particularly when the observed proportion of new infection was high. The CIF approach provides an alternative approach for derivation of failure estimates in antimalarial trials, particularly in high transmission settings.
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| 25. |
- Ho, Anna Y. Q., et al.
(author)
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Evidence for Late-stage Eruptive Mass Loss in the Progenitor to SN2018gep, a Broad-lined Ic Supernova : Pre-explosion Emission and a Rapidly Rising Luminous Transient
- 2019
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In: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 887:2
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Journal article (peer-reviewed)abstract
- We present detailed observations of ZTF18abukavn (SN2018gep), discovered in high-cadence data from the Zwicky Transient Facility as a rapidly rising (1.4 +/- 0.1 mag hr(-1)) and luminous (M-g,M- peak = -20 mag) transient. It is spectroscopically classified as a broad-lined stripped-envelope supernova (Ic-BL SN). The high peak luminosity (L-bol greater than or similar to 3 x 10(44) erg s(-1)), the short rise time (t(rise) = 3 days in g band), and the blue colors at peak (g-r similar to -0.4) all resemble the high-redshift Ic-BL iPTF16asu, as well as several other unclassified fast transients. The early discovery of SN2018gep (within an hour of shock breakout) enabled an intensive spectroscopic campaign, including the highest-temperature (T-eff greater than or similar to 40,000 K) spectra of a stripped-envelope SN. A retrospective search revealed luminous (M-g similar to M-r approximate to -14 mag) emission in the days to weeks before explosion, the first definitive detection of precursor emission for a Ic-BL. We find a limit on the isotropic gamma-ray energy release E-gamma,E- iso < 4.9 x 10(48) erg, a limit on X-ray emission L-X < 10(40) erg s(-1), and a limit on radio emission nu L-v less than or similar to 10(37) erg s(-1). Taken together, we find that the early (< 10 days) data are best explained by shock breakout in a massive shell of dense circumstellar material (0.02 M-circle dot) at large radii (3 x 10(14) cm) that was ejected in eruptive pre-explosion mass-loss episodes. The late-time (> 10 days) light curve requires an additional energy source, which could be the radioactive decay of Ni-56.
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| 26. |
- Mineo Bianchi, F, et al.
(author)
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Posterior muscle-fascial reconstruction and knotless urethro-neo bladder anastomosis during robot-assisted radical cystectomy: Description of the technique and its impact on urinary continence
- 2019
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In: Archivio italiano di urologia, andrologia : organo ufficiale [di] Societa italiana di ecografia urologica e nefrologica. - : PAGEPress Publications. - 2282-4197. ; 91:1, s. 5-10
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Journal article (peer-reviewed)abstract
- Objective: The aim of our study is to describe the use of posterior muscle-fascial reconstruction during urethro-ileal anastomosis in bladder cancer (BC) patients submitted to robot-assisted radical cystectomy (RC) with orthotopic neobladder (ON) and its role in facilitating day- and night-time continence recovery during a 12-month follow up. Materials and methods: We prospectively collected data from 42 consecutive patients who underwent RARC with totally intracorporeal ON and extended pelvic lymph node dissection (PLND) at our Institution from June 2014 to October 2017. Prior to the urethro-neobladder anastomosis we reconstructed the Denonvilliers Fascia (DF) as previously described for radical prostatectomy using a bidirectional barbed suture. Day and night-time recovery rates were reported at 3, 6 and 12 months after surgery, with continent patients being those using either no urinary pads or 1 safety pads. Results: Median age at surgery was 63 yrs, 41 (97.6%) patients were male. 28 (66.7%) patients presented a clinical T2 disease. Median operative time and median ON reconstruction time were 450 minutes and 180 minutes respectively. 13 (31%) individuals had non-organ confined disease, with 11 (26.2%) patients with positive lymph nodes (median 3 positive lymph nodes) and 2 (4.8%) with non-urothelial cancer at final pathologic examination. Median hospital stay and median catheterization time were 7 (IQR 7-8) and 21 (IQR 19-22). During first 30 post-operative days we recorded 7 (16.7%) low-grade Clavien and 2 (4.8%) IIIa Clavien complications, whereas between 30 and 90 postoperative days we recorded 4 (9.5%) low-grade, 4 (9.5) IIIa and 1 (2.4%) IIIb complications. Day-time and night-time continence rates were 61.9% vs 52.4%, 73.8% vs 64.3% and 90.5% vs 73.8% at three, six and twelve months follow up. Day-time continence was significantly superior in the younger group (97% vs 57%, p 0.01); night-time continence rates were also superior among < 70 yrs patients, despite not reaching statistical significance (77% vs 57%, p 0.3). Conclusions: Posterior muscle-fascial reconstruction aids continence recovery in BC patients undergoing RARC with ON, with younger and fitter patients most benefitting from ON reconstruction.
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| 27. |
- Taddia, Francesco, et al.
(author)
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iPTF15dtg : a double-peaked Type Ic supernova from a massive progenitor
- 2016
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In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 592
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Journal article (peer-reviewed)abstract
- Context. Type Ic supernovae (SNe Ic) arise from the core-collapse of H-(and He-) poor stars, which could either be single Wolf-Rayet (WR) stars or lower-mass stars stripped of their envelope by a companion. Their light curves are radioactively powered and usually show a fast rise to peak (similar to 10-15 d), without any early (in the first few days) emission bumps (with the exception of broad-lined SNe Ic) as sometimes seen for other types of stripped-envelope SNe (e.g., Type IIb SN 1993J and Type Ib SN 2008D). Aims. We have studied iPTF15dtg, a spectroscopically normal SN Ic with an early excess in the optical light curves followed by a long (similar to 30 d) rise to the main peak. It is the first spectroscopically-normal double-peaked SN Ic to be observed. Our aim is to determine the properties of this explosion and of its progenitor star. Methods. Optical photometry and spectroscopy of iPTF15dtg was obtained with multiple telescopes. The resulting light curves and spectral sequence are analyzed and modeled with hydrodynamical and analytical models, with particular focus on the early emission. Results. iPTF15dtg is a slow rising SN Ic, similar to SN 2011bm. Hydrodynamical modeling of the bolometric properties reveals a large ejecta mass (similar to 10 M-circle dot) and strong Ni-56 mixing. The luminous early emission can be reproduced if we account for the presence of an extended (greater than or similar to 500 R-circle dot), low-mass (greater than or similar to 0.045 M-circle dot) envelope around the progenitor star. Alternative scenarios for the early peak, such as the interaction with a companion, a shock-breakout (SBO) cooling tail from the progenitor surface, or a magnetar-driven SBO are not favored. Conclusions. The large ejecta mass and the presence of H-and He-free extended material around the star suggest that the progenitor of iPTF15dtg was a massive (greater than or similar to 35 M-circle dot) WR star that experienced strong mass loss.
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| 28. |
- Zema, Vanessa, 1991, et al.
(author)
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Cosinus: A NaI-based cryogenic calorimeter for direct dark matter search
- 2019
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In: Nuovo Cimento della Societa Italiana di Fisica C. - 2037-4909 .- 1826-9885. ; 42:5
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Journal article (peer-reviewed)abstract
- For two decades, extraordinary effort has been devoted to clarifying the controversial results in direct dark matter detection. The claim of DAMA/LIBRA for a dark matter annual modulation signal is in apparent contradiction with most of the results of the other direct detection experiments, but a material-independent check of this signal can still be decisive. For this reason, COSINUS aims to develop a sodium iodide-based cryogenic scintillating calorimeter, whose two-channel readout of light and phonon allows an event-by-event discrimination of the dominant β/γ-background from the sought-for nuclear recoils.
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| 29. |
- Caberlotto, L, et al.
(author)
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Cross-disease analysis of Alzheimer's disease and type-2 Diabetes highlights the role of autophagy in the pathophysiology of two highly comorbid diseases
- 2019
-
In: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9:1, s. 3965-
-
Journal article (peer-reviewed)abstract
- Evidence is accumulating that the main chronic diseases of aging Alzheimer’s disease (AD) and type-2 diabetes mellitus (T2DM) share common pathophysiological mechanisms. This study aimed at applying systems biology approaches to increase the knowledge of the shared molecular pathways underpinnings of AD and T2DM. We analysed transcriptomic data of post-mortem AD and T2DM human brains to obtain disease signatures of AD and T2DM and combined them with protein-protein interaction information to construct two disease-specific networks. The overlapping AD/T2DM network proteins were then used to extract the most representative Gene Ontology biological process terms. The expression of genes identified as relevant was studied in two AD models, 3xTg-AD and ApoE3/ApoE4 targeted replacement mice. The present transcriptomic data analysis revealed a principal role for autophagy in the molecular basis of both AD and T2DM. Our experimental validation in mouse AD models confirmed the role of autophagy-related genes. Among modulated genes, Cyclin-Dependent Kinase Inhibitor 1B, Autophagy Related 16-Like 2, and insulin were highlighted. In conclusion, the present investigation revealed autophagy as the central dys-regulated pathway in highly co-morbid diseases such as AD and T2DM allowing the identification of specific genes potentially involved in disease pathophysiology which could become novel targets for therapeutic intervention.
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| 30. |
- Ferri, F., et al.
(author)
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Donor small-droplet macrovesicular steatosis affects liver transplant outcome in HCV-negative recipients
- 2019
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In: Canadian Journal of Gastroenterology. - : Hindawi Limited. - 0835-7900 .- 2291-2789 .- 2291-2797. ; 2019
-
Journal article (peer-reviewed)abstract
- - Background. No data are available on liver transplantation (LT) outcome and donor liver steatosis, classified as large droplet macrovesicular (Ld-MaS), small-droplet macrovesicular (Sd-MaS), and true microvesicular (MiS), taking into account the recipient Hepatitis C virus (HCV) status. Aim. We investigate the impact of allograft steatosis reclassified according to the Brunt classification on early graft function and survival after LT. Methods. We retrospectively reviewed 204 consecutive preischemia biopsies of grafts transplanted in our center during the period 2001-2011 according to recipient HCV status. Results. The median follow-up after LT was 7.5 years (range: 0.0-16.7). In negative recipients (n=122), graft loss was independently associated with graft Sd-MaS, in multivariable Cox regression models comprehending only pre-/intraoperative variables (HR=1.03, 95%CI=1.01-1.05; P=0.003) and when including indexes of early postoperative graft function (HR=1.04, 95%CI=1.02-1.06; P=0.001). Graft Sd-MaS>15% showed a risk for graft loss > 2.5-folds in both the models. Graft Sd-MaS>15% was associated with reduced graft ATP content and, only in HCV-recipients, with higher early post-LT serum AST peaks. Conclusions. In HCV-negative recipients, allografts with >15% Sd-MaS have significantly reduced graft survival and show low ATP and higher AST peaks in the immediate posttransplant period. Donors with >15% Sd-MaS have significantly higher BMI, longer ICU stays, and lower PaO2. © 2019 Flaminia Ferri et al.
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