ZFP36 stabilizes RIP1 via degradation of XIAP and cIAP2 thereby promoting ripoptosome assembly

BACKGROUND: ZFP36 is an mRNA binding protein that exerts anti-tumor activity in glioblastoma by triggering cell death, associated to an increase in the stability of the kinase RIP1. METHODS: We used cell death assays, size exclusion chromatography, Co-Immunoprecipitation, shRNA lentivectors and glioma neural stem cells to determine the effects of ZFP36 on the assembly of a death complex containing RIP1 and on the induction of necroptosis. RESULTS: Here we demonstrate that ZFP36 promotes the assembly of the death complex called Ripoptosome and induces RIP1-dependent death. This involves the depletion of the ubiquitine ligases cIAP2 and XIAP and leads to the association of RIP1 to caspase-8 and FADD. Moreover, we show that ZFP36 controls RIP1 levels in glioma neural stem cell lines. CONCLUSIONS: We provide a molecular mechanism for the tumor suppressor role of ZFP36, and the first evidence for Ripoptosome assembly following ZFP36 expression. These findings suggest that ZFP36 plays an important role in RIP1-dependent cell death in conditions where IAPs are depleted

Mass testing of the JUNO experiment 20-inch PMTs readout electronics

The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose, large size, liquid scintillator experiment under construction in China. JUNO will perform leading measurements detecting neutrinos from different sources (reactor, terrestrial and astrophysical neutrinos) covering a wide energy range (from 200 keV to several GeV). This paper focuses on the design and development of a test protocol for the 20-inch PMT underwater readout electronics, performed in parallel to the mass production line. In a time period of about ten months, a total number of 6950 electronic boards were tested with an acceptance yield of 99.1%

Implementation and performances of the IPbus protocol for the JUNO Large-PMT readout electronics

The Jiangmen Underground Neutrino Observatory (JUNO) is a large neutrino detector currently under construction in China. Thanks to the tight requirements on its optical and radio-purity properties, it will be able to perform leading measurements detecting terrestrial and astrophysical neutrinos in a wide energy range from tens of keV to hundreds of MeV. A key requirement for the success of the experiment is an unprecedented 3% energy resolution, guaranteed by its large active mass (20 kton) and the use of more than 20,000 20-inch photo-multiplier tubes (PMTs) acquired by high-speed, high-resolution sampling electronics located very close to the PMTs. As the Front-End and Read-Out electronics is expected to continuously run underwater for 30 years, a reliable readout acquisition system capable of handling the timestamped data stream coming from the Large-PMTs and permitting to simultaneously monitor and operate remotely the inaccessible electronics had to be developed. In this contribution, the firmware and hardware implementation of the IPbus based readout protocol will be presented, together with the performances measured on final modules during the mass production of the electronics

Validation and integration tests of the JUNO 20-inch PMTs readout electronics

The Jiangmen Underground Neutrino Observatory (JUNO) is a large neutrino detector currently under construction in China. JUNO will be able to study the neutrino mass ordering and to perform leading measurements detecting terrestrial and astrophysical neutrinos in a wide energy range, spanning from 200 keV to several GeV. Given the ambitious physics goals of JUNO, the electronic system has to meet specific tight requirements, and a thorough characterization is required. The present paper describes the tests performed on the readout modules to measure their performances.Comment: 20 pages, 13 figure

Far-infrared spectroscopy of thermally annealed tungsten silicide films

The far-infrared transmittance spectrum of tungsten silicide has been observed for the first time. WSi2 polycrystalline films were prepared by coevaporation and chemical-vapour deposition on silicon wafers, and subsequently thermally annealed at different temperatures. The observed structures are interpreted, on the basis of the symmetry properties of the crystal, such as infrared-active vibrational modes. Moreover, the marked lineshape dependence on annealing temperature enables this technique to analyse the formation of the solid silicide phases

OPTICAL STUDY OF NIOBIUM DISILICIDE POLYCRYSTALLINE FILMS

NbSi2 polycrystalline films, coevaporated and thermally annealed, were subjected to chemical and structural characterization, and then studied by reflectance from 0.06 to 6 eV and ellipsometry from 1.4 to 5 eV. The dielectric functions, obtained from Kramers-Kronig analysis and directly from ellipsometry, are also presented. Low-frequency free-carrier response is discussed in terms of the Drude model; the high-frequency interband structures are interpreted on the basis of the calculated density of states and photoemission results. A comparison is made with the optical properties of isoelectronic VSi2 and TaSi2 Polycrystalline films

OPTICAL-CONSTANTS AND ELECTRICAL TRANSPORT PARAMETERS OF HFSI2

HfSi2 polycrystalline thin films, grown by coevaporation of Hf and Si and subsequently annealed at 850-degrees-C, were studied by electrical resistivity measurements (from 10 to 900 K), Hall voltage (from 10 to 300 K), and optical reflectance (at room temperature) from 5 meV to 12 eV. Composition and structure of the films were investigated by Rutherford backscattering spectroscopy and x-ray diffraction. HfSi2 is metallic with (i) a high residual resistivity, (ii) a phonon contribution to the resistivity showing a negative deviation from linearity, and (iii) low-energy interband transitions. Transport measurements yielded a Debye temperature of 430 K, a free-carrier concentration of approximately 4 X 10(21) cm-3, and a mean free path of 139 angstrom. The reflectivity was Kramers-Kronig transformed to obtain the dielectric functions which, at low energies, are discussed in term of the Drude model. The optical parameters agree quite well with transport results, thus permitting one to obtain a reasonable value for the Fermi velocity

Optical and vibrational properties of Cr and Fe disilicides

We present and discuss reflectance and trasmittance measurements on CrSi_2 an FeSi_2 polycristalline films, The strong and sharp structures observed in the 100-700 cm^-1 wavenumber range are interpreted basin on normal modes symmetry properties. We also examine the optical response in the energy region around the band-gap for CrSi_2 and determine the dispersion of its complex refractive index

Far Infrared Vibrational Spectroscopy in CrSi_2

We present and discuss reflectance and trasmittance measurements on CrSi, polycrystalline films in the (100 + 700) cm-' wavenumber range. The spectra show that the compound has a nonmetallic behaviour. The strong and sharp structures observed are interpreted on the basis of the symmetry properties of the normal modes of CrSie, and their strength is attributed to a dynamical charge. Moreover, preliminary lattice dynamicscalculations allow to explain the relative intensity of the infrared-active modes