307 research outputs found

    Validation of the 3-under-2 principle of cell wall growth in Gram-positive bacteria by simulation of a simple coarse-grained model

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    The aim of this work is to propose a first coarse-grained model of Bacillus subtilis cell wall, handling explicitly the existence of multiple layers of peptidoglycans. In this first work, we aim at the validation of the recently proposed "three under two" principle.Comment: Revised introduction, results unchange

    The infrared emission of carbonaceous particles around C-rich IRAS sources

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    The IRAS spectra of 23 carbon-rich sources have been fitted by means of an improved theoretical model based on the Leung-Spagna radiative transfer code and using extinction data obtained in our laboratory for different types of amorphous carbon and silicon carbide submicron particles. The agreement between observations and theoretical spectra is rather good. However, a comparison between the IRAS spectrum of the object 1244710425 (RU Vir) and that recently obtained at UKIRT, for the same object but with higher resolution, seems to open new problems

    Optical, near-IR and XX-ray observations of SN 2015J and its host galaxy

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    SN 2015J was discovered on April 27th 2015 and is classified as a type IIn supernova. At first, it appeared to be an orphan SN candidate, i.e. without any clear identification of its host galaxy. Here, we present the analysis of the observations carried out {by the VLT 8-m class telescope with the FORS2 camera in the R band and the Magellan telescope (6.5 m) equipped with the IMACS Short-Camera (V and I filters) and the FourStar camera (Ks filter)}. We show that SN 2015J resides in what appears to be a very compact galaxy establishing a relation between the SN event and its natural host. We also present and discuss archival and new XX-ray data centred on SN 2015J. At the time of the supernova explosion, Swift/XRT observations were made and a weak X-ray source was detected at the location of SN 2015J. Almost one year later, the same source was unambiguously identified during serendipitous observations by Swift/XRT and XMMXMM-Newton, clearly showing an enhancement of the 0.3-10 keV band flux by a factor ≃30\simeq 30 with respect to the initial state. Swift/XRT observations show that the source is still active in the XX-rays at a level of ≃0.05\simeq 0.05 counts s−1^{-1}. The unabsorbed X-ray luminosity derived from the {\it XMM}-Newton slew and SWIFT observations, Lx≃5×1041L_{x}\simeq 5\times10^{41} erg s−1^{-1}, places SN 2015J among the brightest young supernovae in X-rays.Comment: The Astrophysical Journal, Volume 850, Number

    Immunomodulatory drugs in acute myeloid leukemia treatment

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    Immunomodulatory drugs (IMiDs) are analogs of thalidomide. They have immunomodulatory, antiangiogenic and proapoptotic properties and exert a role in regulating the tumor microenvironment. Recently IMiDs have been investigated for their pleiotropic properties and their therapeutic applications in both solid tumors (melanoma, prostate carcinoma and differentiated thyroid cancer) and hematological malignancies. Nowadays, they are applied in de novo and relapsed/ refractory multiple myeloma, in myelodysplastic syndrome, in del5q syndrome with specific use of lenalidomide and B-cell lymphoma. Several studies have been conducted in the last few years to explore IMiDs possible use in acute myeloid leukemia treatment. Here we report the mechanisms of action of IMiDs in acute myeloid leukemia and their potential future therapeutic application in this disease

    M31 Pixel Lensing PLAN Campaign: MACHO Lensing and Self Lensing Signals

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    We present the final analysis of the observational campaign carried out by the PLAN (Pixel Lensing Andromeda) collaboration to detect a dark matter signal in form of MACHOs through the microlensing effect. The campaign consists of about 1 month/year observations carried out during 4 years (2007-2010) at the 1.5m Cassini telescope in Loiano ("Astronomical Observatory of BOLOGNA", OAB) plus 10 days of data taken in 2010 at the 2m Himalayan Chandra Telescope (HCT) monitoring the central part of M31 (two fields of about 13'x12.6'). We establish a fully automated pipeline for the search and the characterization of microlensing flux variations: as a result we detect 3 microlensing candidates. We evaluate the expected signal through a full Monte Carlo simulation of the experiment completed by an analysis of the detection efficiency of our pipeline. We consider both "self lensing" and "MACHO lensing" lens populations, given by M31 stars and dark matter halo MACHOs, in the M31 and the Milky Way (MW), respectively. The total number of events is compatible with the expected self-lensing rate. Specifically, we evaluate an expected signal of about 2 self-lensing events. As for MACHO lensing, for full 0.5 (0.01) solar mass MACHO halos, our prediction is for about 4 (7) events. The comparatively small number of expected MACHO versus self lensing events, together with the small number statistics at disposal, do not enable us to put strong constraints on that population. Rather, the hypothesis, suggested by a previous analysis, on the MACHO nature of OAB-07-N2, one of the microlensing candidates, translates into a sizeable lower limit for the halo mass fraction in form of the would be MACHO population, f, of about 15% for 0.5 solar mass MACHOs.Comment: ApJ accepted, 13 pages, 5 figures, 2 table

    Slott-Agape Project

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    SLOTT-AGAPE (Systematic Lensing Observation at Toppo Telescope - Andromeda Gravitational Amplification Pixel Lensing Experiment) is a new collaboration project among international partners from England, France, Germany, Italy and Switzerland that intends to perform microlensing observation by using M31 as target. The MACHOs search is made thanks to the pixel lensing technique.Comment: 4 pages, 2 figures, proceeding of XLIII Congresso della Societa' Astronomica Italiana, Napoli, 4-8 Maggio, 199

    Overview of the molecular determinants contributing to the expression of Psoriasis and Psoriatic Arthritis phenotypes

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    Psoriasis and psoriatic arthritis are multifactorial chronic disorders whose etiopathogenesis essentially derives from the alteration of several signalling pathways and the co-occurrence of genetic, epigenetic and non-genetic susceptibility factors that altogether affect the functional and structural property of the skin. Although shared and differential susceptibility genes and molecular pathways are known to contribute to the onset of pathological phenotypes, further research is needed to dissect the molecular causes of psoriatic disease and its progression towards Psoriatic Arthritis. This review will therefore be addressed to explore differences and similarities in the etiopathogenesis and progression of both disorders, with a particular focus on genes involved in the maintenance of the skin structure and integrity (keratins and collagens), modulation of patterns of recognition (through Toll-like receptors and dectin-1) and immuno-inflammatory response (by NLRP3-dependent inflammasome) to microbial pathogens. In addition, special emphasis will be given to the contribution of epigenetic elements (methylation pattern, non-coding RNAs, chromatin modifiers and 3D genome organization) to the etiopathogenesis and progression of psoriasis and psoriatic arthritis. The evidence discussed in this review highlights how the knowledge of patients' clinical and (epi)genomic make-up could be helpful for improving the available therapeutic strategies for psoriasis and psoriatic arthritis treatment

    NGS Analysis for Molecular Diagnosis of Retinitis Pigmentosa (RP): Detection of a Novel Variant in PRPH2 Gene

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    This work describes the application of NGS for molecular diagnosis of RP in a family with a history of severe hypovision. In particular, the proband received a clinical diagnosis of RP on the basis of medical, instrumental examinations and his family history. The proband was subjected to NGS, utilizing a customized panel including 24 genes associated with RP and other retinal dystrophies. The NGS analysis revealed a novel missense variant (c.668T > A, I223N) in PRPH2 gene, which was investigated by segregation and bioinformatic analysis. The variant is located in the D2 loop domain of PRPH2, which is critical for protein activity. Bioinformatic analysis described the c.668T > A as a likely pathogenic variant. Moreover, a 3D model prediction was performed to better characterize the impact of the variant on the protein, reporting a disruption of the \u3b1-helical structures. As a result, the variant protein showed a substantially different conformation with respect to the wild-type PRPH2. The identified variant may therefore affect the oligomerization ability of the D2 loop and, ultimately, hamper PRPH2 proper functioning and localization. In conclusion, PRPH2_c.668T > A provided a molecular explanation of RP symptomatology, highlighting the clinical utility of NGS panels to facilitate genotype\u2013phenotype correlations
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