The DArk Matter Particle Explorer (DAMPE) is a space-based particle detector launched in a sun-synchronous orbit on December 17, 2015 from the Jiuquan Satellite Launch Center, in China. The main ...goals of the DAMPE mission include the study of the electron–positron energy spectrum, the study of galactic cosmic rays, gamma-ray astronomy, and indirect dark matter searches. Among its subdetectors, the deep BGO calorimeter makes DAMPE able to measure the cosmic-ray electrons and positrons (CRE) spectrum up to 10 TeV and cosmic-ray nuclei (CR) spectra up to 100 TeV, with unprecedented energy resolution. This high-energy region is important in order to search for possible nearby CRE sources, for dark matter signatures, and to have a better understanding of CR acceleration and propagation mechanisms inside the Galaxy. A break at about 1 TeV was clearly evidenced by DAMPE in the CRE energy spectrum. Moreover, DAMPE precise measurements of CR protons and helium spectra, confirmed the hardening at few hundreds GeV
and revealed a spectral softening at about 14 and 30 TeV for
and He, respectively, suggesting a rigidity dependent mechanism. About 250 gamma ray sources were detected and identified. Spectral analyses on medium and heavy mass nuclei are currently ongoing. The main results of the mission will be presented, along with ongoing activities.
The High Energy Cosmic Radiation Detection (HERD) facility, onboard the future China’s Space Station (CSS), will provide high quality data on charged cosmic rays and gamma rays in the energy range ...from few GeV to PeV. HERD will be equipped with a fine granularity cubic crystals calorimeter and a precision tracker detector. The entire instrument will be surrounded by a Plastic Scintillator Detector (PSD) that will be used to discriminate charged from neutral particles in order to correctly identify gamma-rays and nuclei. One proposed configuration for the HERD PSD consists of tiles of plastic scintillator, optically coupled to SiPMs. In 2019-2020, two beam tests were performed at CNAO (Centro Nazionale di Adroterapia Oncologica) in Pavia (Italy), exposing some PSD tiles, equipped with SiPMs, to low-beta p and C ion beams in order to evaluate the detector response to heavy ions. Spatial and temporal resolution were also evaluated using a radioactive source.
Plastic scintillators are widely used for anti-coincidence systems and for the identification of charged cosmic-ray nuclei in satellite experiments. For this reason, a plastic scintillator detector ...(PSD) should have a high detection efficiency for charged cosmic rays and a very good capability of measuring charges. We implemented a full and customizable simulation tool to investigate the performance of a PSD coupled to Silicon Photomultipliers. The overall performance of the detector is studied by tracking optical photons produced inside the scintillator. The simulation will be used for the design of a PSD for future space experiments, such as HERD, AMEGO, e-Astrogam. In this work we investigated in detail the effect of Birks’ saturation in the discrimination of charged ions up to iron nuclei. We will show the comparison between simulations and measurements conducted on prototype scintillator tiles.
Satellite experiments for gamma-ray and cosmic-ray detection employ plastic scintillators to discriminate charged from neutral particles in order to correctly identify gamma-rays and charged nuclei. ...The High Energy Cosmic Radiation Detection (HERD) facility will be among these experiments, to be installed onboard the future Chinese Space Station (CSS), to detect cosmic-rays and gamma-rays up to TeV energies. The plastic scintillator detector (PSD) will consist of scintillator tiles or bars coupled to Silicon Photomultipliers (SiPMs). To discriminate gamma-rays from charged particles and measure the ion charge up to iron nuclei a wide dynamic range is required, from few tens up to thousands of photoelectrons. We have equipped a plastic scintillator tile prototype with SiPMs produced by Hamamatsu and AdvanSiD and coupled their analog signals to the DT5550W board based on the CITIROC ASIC, produced by CAEN SpA. The CITIROC ASIC allows both the formation of a fast trigger with a configurable threshold and the digitization of analog waveforms after a preamplification and shaping stage along two paths with different gain settings. The performance of our prototype will be shown.
Living organisms have evolved various mechanisms to control their metabolism and response to various stresses, allowing them to survive and grow in different environments. In eukaryotes, the highly ...conserved mechanistic target of rapamycin (mTOR) signaling pathway integrates both intracellular and extracellular signals and serves as a central regulator of cellular metabolism, proliferation and survival. A growing body of evidence indicates that mTOR signaling is closely related to another cellular protection mechanism, the DNA damage response (DDR). Many factors important for mTOR pathway are also involved in the DDR. The SEA/GATOR complex is an inhibitor of the mTORC1 pathway. In mammals the GATOR1 complex is composed of the proteins DEPDC5, NPRL2 and NPRL3. We characterized mammalian cells overexpressing the GATOR1 component NPRL2 and found that in the cells with active p53, ectopic expression of NPRL2 induces NOX2-dependent production of reactive oxygen species and DNA damage. Overexpressed NPRL2 accumulates in the nucleus, together with apoptosis-inducing factor (AIF). These events are accompanied by phosphorylation of p53, activation of a DNA-damage response and cell cycle arrest in G1 phase, followed by apoptosis. In the cells negative for active p53, NPRL2 ectopic expression leads to activation of CHK1 or CHK2 kinases and cell cycle arrest in S or G2/M phases. Combined, these results demonstrate a new role for the NPRL2, distinct from its function in mTORC1 regulation.
Malignant melanoma is the most malignant tumours of skin and mucous membranes mainly due to its aggressive biological behaviour and tendency to generate early metastases. Unfortunately, the ...mechanisms underlying the development, progression and the expression of an aggressive melanoma phenotype still remain largely unknown.
The purpose of this study was to determine whether a multi-panel of molecular transcripts can be predictive for risk of recurrent disease in malignant melanoma patients.
Peripheral blood was collected from 31 malignant melanoma patients in follow-up for melanoma and from 30 healthy volunteers randomly selected. Each specimen was examined by qRT-PCR analysis for the expression of six markers: PAX3d, TYR, MITFm, MCAM, TGFβ2 and ABCB5. Malignant melanoma patients expressed an important number of markers, with a median value of four markers. Only PAX3d displayed a trend in terms of differences when the levels of gene expression were made in function of Breslow index. Furthermore, PAX3d showed the best diagnostic capacity among the remaining residual markers or in combination with TGFβ2 and MTIF.
We demonstrated the usefulness of multimarker qRT-PCR to detect circulating melanoma cells in blood and to potentially assessing patient disease status or progression, especially when PAX3d was used in combination with MTIFm and TGFβ2.
•A reliable multimarker panel, based on standardized calibration curves built with plasmid constructs, allowed us to calculate a number of copies of melanoma marker transcript.•Multimarker absolute qRT-PCR approach is a sensitive and specific quantitative assay able to detect circulating melanoma cells transcripts in blood, potentially correlating with the number of circulating melanoma cells.•The simultaneous analysis of multiple markers can potentially overcome problems such as, false negatives and false positives.
In this study, we report that the release of IL‐1 receptor antagonist (IL‐1ra) from IL‐4‐stimulated neutrophils is markedly enhanced in the presence of IL‐10. We also show that up‐regulation of ...IL‐1ra release by IL‐10 in IL‐4‐stimulated neutrophils takes place through IL‐1ra mRNA stabilization and enhancement of IL‐1ra de novo synthesis. Furthermore, we report that the ability of IL‐10 to up‐regulate IL‐1ra mRNA expression in IL‐4‐treated neutrophils requires 5–6 h and it is preceded by the acquisition of the capacity to activate Stat3 tyrosine phosphorylation. This latter response to IL‐10 was strictly dependent on the levels of expression of IL‐10R1, which were in fact significantly increased by IL‐4 in cultured neutrophils via a signaling pathway sensitive to the serine/threonine kinase inhibitor H‐7. Collectively, our data emphasize the central role of IL‐10R1 expression in regulating cell responsiveness to IL‐10. In addition, the fact that IL‐10 strongly up‐regulates IL‐1ra production in IL‐4‐activated neutrophils uncovers a novel mechanism whereby IL‐10 and IL‐4 cooperate to negatively modulate the inflammatory responses.
On the basis of fine mapping of a quantitative trait loci region of BTA3 for milk fat content, an examination of the comparative map between cattle and human indicates that the annexin 9 protein gene ...(ANXA9) and the fatty acid transport protein type 3 gene (SLC27A3) are two strong candidate genes. The objective of the present study is to isolate, map and characterize these genes and identify polymorphisms that could be further utilized in linkage or association studies. Furthermore, two new genes which are in the same region, cingulin protein gene (CGN) and lysophosphatidic acid phosphatase protein gene (ACP6) were studied. DNA fragments (869, 1778, 1933 and 2618 bp) corresponding to partial sequences of ACP6,CGN,ANXA9 and SLC27A3 genes were isolated. Direct sequencing of PCR products amplified from different cattle breeds revealed 1, 4, 4 and 2 SNPs for ACP6, CGN,ANXA9 and SLC27A3, respectively. For ANXA9 one SNP was located in exon 5 (A-->G 951) resulting in an amino acid change from histidine to arginine. Finally, ACP6,CGN,ANXA9 and SLC27A3 genes were located on chromosome 3 between ILSTS096 and BMS819 markers, in a region in which quantitative trait loci (QTL) for several milk traits have been described.
The bismuth germanium oxide (BGO) electromagnetic calorimeter, which is characterized by a large detection energy range of 5 GeV–10 TeV for high-energy cosmic-ray electrons/positrons (CREs) and ...γ-rays, is the key sub-detector of the Dark Matter Particle Explorer (DAMPE). A careful and comprehensive calibration is essential for conducting accurate detector energy measurement. In this study, we present a method based on the ATmospheric Muon Neutrino Calculation 3-dimensional version (ATMNC3) software package, which achieves a stable and homogeneous inter-calibration in orbit for the DAMPE calorimeter.
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