Development of a very low-noise cryogenic pre-amplifier for large-area SiPM devices

Silicon Photomultipliers (SiPMs) are an excellent candidate for the development of large-area light sensors. Large SiPM-based detectors require low-noise pre-amplifiers to maximize the signal coupling between the sensor and the readout electronics. This article reports on the development of a low-noise transimpedance amplifier sensitive to single-photon signals at cryogenic temperature. The amplifier is used to readout a 1 cm$^{2}$ SiPM with a signal to noise ratio in excess of 40

Ageing and recovering of glass RPC

The glass Resistive Plate Chambers efficiency before and after water vapour flushing have been studied. The efficiency has been observed to rapidly drop to the level of 30% after a few days. After few hours of ammonia flushing, a full recover of the device occurred. Surprisingly, further flushing with water vapour had no effect on the efficiency, suggesting a treatment before the use in an experiment and/or whenever the performance is poor. In this work experimental results on tests at high temperature (up to 55∘C), high rate (up to 100Hz/cm2) and ageing (up to 10mC/cm2) are reported

Let-7g and miR-21 expression in non-small cell lung cancer: correlation with clinicopathological and molecular features

MicroRNAs (miRNAs) play a key role in cancer pathogenesis and are involved in several human cancers, including non-small cell lung cancer (NSCLC). This study evaluated Let-7g and miR-21 expression by quantitative real-time PCR in 80 NSCLC patients and correlated the results with their main clinicopathological and molecular features. MiR-21 expression was significantly higher in NSCLC tissues compared to non-cancer lung tissues (p<0.0001), while no significant changes in Let-7g expression were observed between the tumor and normal lung tissues. Target prediction analysis led to the identification of 26 miR-21 and 24 Let-7g putative target genes that play important roles in cancer pathogenesis and progression. No significant association was observed between the analysed miRNAs and the main clinicopathological or molecular characteristics of the NSCLC patients, although both miRNAs were downregulated in squamous cell carcinomas compared to adenocarcinomas. Noteworthy, we observed a significant association between low Let-7g expression and metastatic lymph nodes at diagnosis (p=0.046), as well as between high miR-21 expression and K-Ras mutations (p=0.0003). Survival analysis did not show any significant correlation between prognosis and the analysed miRNAs, although the patients with a high Let-7g and miR-21 expression showed a significantly lower short-term progression-free survival (p=0.01 and p=0.0003, respectively) and overall survival (p=0.023 and p=0.0045, respectively). In conclusion, we showed that Let-7g and miR-21 expression was deregulated in NSCLC and we demonstrated a strong relationship between miR-21 overexpression and K-Ras mutations. Our data indicate that Let-7g and miR-21 profiling combined with the determination of K-Ras mutational status may be considered a useful biomarker for a more effective molecular characterization and clinical management of NSCLC patients

Morphostructural mapping of Borealis Planitia, Mercury

Orbital data from the MESSENGER spacecraft show that a significant portion of Mercury’s northern hemisphere is covered by smooth plains, which are interpreted to be flood volcanic material and/or impact melt. The smooth plains show pervasive tectonic structures and encompass a broad raised bulge of uncertain geophysical interpretation. In this work, we focus on the mapping of all the morphostructures within the northern smooth plains, aiming at providing a useful dataset for further studies about the mapped area. The structural map is obtained through a twofold process: first with an automatic mapping, using an algorithm to identify all the lineaments from a DEM; and second with a visual inspection and classification of the results of the algorithm in a GIS environment. The final maps are drafted at two different scales, 1:300,000 and 1:600,000. With this approach, we mapped and characterized more than fifty thousand lines marking scarps on the surface, creating a database with several morphometric attributes for each of the identified scarps (e.g. length, azimuth, and height), which can be used for geostatistical study of smooth plains tectonics. Our structural map reveals that: (i) the area is broadly dominated by wrinkle ridges, ghost crater assemblages of lineaments, and scarps related to impact crater processes (e.g. radial faults, secondary crater chains, ejecta emplacement) and that (ii) the amount of strain was not evenly accommodated throughout the northern smooth plains

Development of a Novel Single-Channel, 24 cm 2

We report on the realization of a novel SiPM-based, cryogenic photosensor with an active area of 24 cm$^2$ that operates as a single-channel analog detector. The device is capable of single photon counting with a signal to noise ratio better than 13, a dark rate lower than $10^{-2}$ cps/mm$^2$ and an overall photon detection efficiency significantly larger than traditional photomultiplier tubes. This development makes SiPM-based photosensors strong candidates for the next generation of dark matter and neutrino detectors, which will require multiple square meters of photosensitive area, low levels of intrinsic radioactivity and a limited number of detector channels

The geologically recent areas as one key target for identifying active volcanism on Venus

The recently selected NASA VERITAS and DAVINCI missions, the ESA EnVision, the Roscosmos Venera-D will open a new era in the exploration of Venus. One of the key targets of the future orbiting and in-situ investigations of Venus is the identification of volcanically active areas on the planet. The study of the areas characterized by recent or ongoing volcano-tectonic activity can inform us on how volcanism and tectonism are currently evolving on Venus. Following this key target, the manuscript by Brossier et al. (2022) (https://doi.org/10.1029/2022GL099765) extends the successful approach and methodology used by previous works to Ganis Chasma in Atla Regio. We comment here on the main results of the manuscript published by Brossier et al. (2022) (https://doi.org/10.1029/2022GL099765) and discuss the important implications of their work for the future orbiting and in-situ investigation of Venus. Their results add further lines of evidence indicating possibly recent volcanism on Venus

The geologically recent areas as one key target for identifying active volcanism on Venus.

The recently selected NASA VERITAS and DAVINCI missions, the ESA EnVision, the Roscosmos Venera-D will open a new era in the exploration of Venus. One of the key targets of the future orbiting and in-situ investigations of Venus is the identification of volcanically active areas on the planet. The study of the areas characterized by recent or ongoing volcano-tectonic activity can inform us on how volcanism and tectonism are currently evolving on Venus. Following this key target, the manuscript by Brossier et al. (2022) (https://doi.org/10.1029/2022GL099765) extends the successful approach and methodology used by previous works to Ganis Chasma in Atla Regio. We comment here on the main results of the manuscript published by Brossier et al. (2022) (https://doi.org/10.1029/2022GL099765) and discuss the important implications of their work for the future orbiting and in-situ investigation of Venus. Their results add further lines of evidence indicating possibly recent volcanism on Venus

Idunn Mons as the landing site of the Venera-D mission:scientific relevance and possible operational tests on Mount Etna.

Along with the recently selected NASA DAVINCI [1] and VERITAS [2] missions, and with the ESA EnVision mission [3], the Roscosmos Venera-D mission [4, 5] opens the new decade of Venus exploration. Among these missions, the Venera-D is the only one to be equipped with a lander which could drill the surface of Venus and analyze its chemical composition. For this reason, it is crucial to select a future landing site based on its scientific relevance, as well as on safety constraints. We propose here Idunn Mons (Fig. 1a), a major large volcano of Imdr Regio, as the landing site for the Venera-D mission. We also indicate Mount Etna in Italy (Fig. 1b) as a suitable test site on Earth for drilling tests and in-situ elemental and mineralogical analyses [6, 7]