The High-Energy Particle Detector (HEPD) module is designed to measure the pitch angle and energy of electrons and protons fluxes trapped in the Earth Magnetosphere with energies 3-100 MeV and 30-300 ...MeV respectively. Because of the launch of the CSES-02 satellite, an interesting option for improving the HEPD is to endow the tracking module with ALPIDE monolithic active pixel, specifically developed for the ITS upgrade of ALICE experiment at CERN. In this work we present the project of a modular and compact particle tracker made of 5 turrets, making use of 150-pixel sensors equipped with Hybrid Integrated Circuit (HIC) and supported by Carbon Fiber Reinforced Plastics (CFRPs) staves housed in an aluminum case. All envisaged solutions have been validated with an intense campaign of qualification tests, concerning vibrations and thermal stresses. The HEPD-02 tracker project foreruns the massive usage of CFRPs for space initiatives both of scientific and exploratory nature.
Abstract
The Limadou collaboration includes all Italian scientists working on the project CSES (China Seismo-Electromagnetic Satellite), a constellation of satellites equipped with the most advanced ...technologies for correlating ionosphere perturbations with the occurrence of seismic events 2. For the launch of CSES-02, scheduled for mid-2022, the collaboration is realizing the high-energy particle detector 1, aimed at detecting electrons and protons trapped in Earth’s magnetosphere, with energies 5 MeV–100 MeV and 30 MeV–300 MeV respectively. This payload consists of a particle tracker, a trigger system and a calorimeter, which work in time-coincidence to accurately identify particles and measure their energy and trajectory. The tracker is based on monolithic active pixel sensors ALPIDE 4, an innovative platform with superior performances in the field of pixel detectors, developed for the upgrade of the ALICE experiment 5 at the LHC, at CERN. The challenge in the construction of the tracker has been to adapt the ALPIDE technology to the space environment and to the specifications of the space register. Lightness and stiffness, essential features for structures in a tracker module, needed to balance with the need for withstanding structural and vibrational stress in the extended range of temperature occurring in the launch phase. Proper material choice with high thermal conductivity for the heat dissipation, innovative design of thermal paths and structural test results guided the project of mechanics. The modular particle tracker consists of 5 turrets, each one made of 3 stacked staves, with 150 pixel sensors in total. For readout and control purposes, ALPIDE sensors are wire-bonded to flexible printed circuits, which enhances the fragility of the system and makes handling critical. Sensor supports in carbon fiber reinforced plastic and an external aluminum frame preserve the mechanical integrity and provide the essential thermal bridges for heat dissipation. We provide results from the intense campaign of structural, thermal and vibrational qualification tests that have been performed in compliance with the procedures required by the space register. It regards structure, module and turret elements. The envisaged solution is a novelty in the field of space applications and paves the way for important developments for particle and astroparticle physics experiments.
Mangiferin is a natural xanthone glycoside with therapeutic potential. Herein, its cytotoxic properties were explored in a human cell model of breast adenocarcinoma. The results supported the ...multi-target nature of mangiferin action, as the inhibition of three enzymatic systems, namely HMG-CoA reductase, the proteasome and plasmin, respectively in charge of regulating cholesterol homeostasis, protein turnover and cell adhesion, was documented for the first time. Globally, mangiferin was able to selectively block breast cancer cell growth by inducing apoptosis and by arresting cell proliferation through a combined action on cholesterol and proteasome pathways, as well as to inhibit plasmin-mediated mechanisms of cell migration.
A ruthenium(
ii
)
p
-cymene derivative of quercetin was synthesized and functionally tested for cholesterol-lowering ability
via
direct 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGR) inhibition. ...Ruthenium complexation dramatically increased the inhibition potency of the parent quercetin toward HMGR, with a consequent enhancement of the cholesterol-lowering effect in hepatic cells.
A ruthenium(
ii
)
p
-cymene derivative of quercetin was synthesized and functionally tested for cholesterol-lowering ability
via
direct 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGR) inhibition.
We present thick, uniform and rather flat melanin films obtained using spray deposition. The morphology of the films was investigated using Scanning Electron Microscopy (SEM) and Atomic Force ...Microscopy (AFM). Temperature-dependent electrical resistance of melanin thin films evidenced a semiconductor-like character and a hysteretic behavior linked to an irreversible process of water molecule desorption from the melanin film. X-ray Photoelectron Spectroscopy (XPS) was carried out to analyze the role of the functional groups in the primary and secondary structure of the macromolecule, showing that the contribution of the 5,6-dihydroxyindole-2-carboxylic acid (DHICA) subunit to the molecule is about 35%. Comparison of the optical absorption of the thick (800nm) and thin (80nm) films showed a spectral change when the thickness increases. From in vacuum photoconductivity (PC) measured at controlled temperatures, we suggest that the melanin films exhibit a possible charge transport mechanism by means of delocalized
states along the stacked planar secondary structure.
The effect of a group of natural flavonoids on human thrombin amidolytic activity was investigated using a spectrophotometric inhibition assay while information on the kinetics and thermodynamics was ...obtained using optical biosensor techniques. All the flavonoids tested acted as reversible inhibitors, and the quercetin–thrombin complex was found to be most stable at pH=7.5. Docking analysis indicated that quercetin's inhibitory behavior could be related to its planar structure and low steric hindrance, and to its ability to form a critical H-bond with thrombin His57.
Background
During SARS-CoV-2 pandemic, various studies have shown a significant reduction of Emergency Department (ED) presentations for acute cardiac diseases requiring in-hospital management. The ...aim of our study was to quantify hospital admission and mortality, comparing pandemic period and pre-pandemic period in different countries.
Methods
We performed an updated meta-analysis of observational studies to quantify on a large basis the impact of the SARS-CoV-2 outbreak on patients admitted to the ED for STEMI and NSTEMI. The literature research was conducted on PubMed, EMBASE, Scopus, Science Direct, Web of Science and Cochrane database registry on 6 January 2022. We performed a random-effect model meta-analysis.
Results
A total of 61 studies were included: came from Italy, China, Germany, Israel, Turkey, France, Helvetic Confederation, India, Poland, Spain, US, UK, Albania, Austria, Egypt, Greece, Iran, Ireland, Japan, Pakistan, Portugal, Saudi Arabia and Canada. Hospital admissions for STEMI decreased in most country. The countries with the high levels of reduction were Italy (IRR = 0.68) and Germany (IRR = 0.69). Mortality rates for STEMI increased differently among countries analyzed: p = 0.003. The highest mortality rate was in Serbia (OR = 2.15), followed by Italy (OR = 1.97), Pakistan (OR = 1.69) and France (OR = 1.55). Among the High-Income countries, the highest mortality rate was in Italy (OR = 3.71), the highest among the Upper-Middle-Income was in Serbia (OR = 2.15) and the highest among Low- Middle-Income was in Pakistan (OR = 1.69). Regarding NSTEMI, hospital admissions showed that Italy had the lowest value for with IRR = 0.59. Among countries, the meta-regression subgroups analysis, showed statistical difference (p < 0.001).
Conclusions
Our meta-analysis may represent a robust snapshot that might help healthcare systems manage and assist an expected higher number of people coming to the hospitals for severe, post-acute cardiological issues in the future.
Key messages
* The study shows hospital admission and mortality, comparing pandemic period and pre-pandemic period in different countries.
* Epidemiological data suggests that one-fourth to one-third of MI patients, in large areas of the globe, during the COVID-19 pandemic in 2020, remained at home and did not have access to ED.
The Tronto River (southern Marche region of central Italy) is located in an area with neighboring industrial activities and is contaminated with domestic and industrial wastewater. Water quality data ...analyses revealed the presence of a mixture of low levels of heavy metals and organic compounds. The effects of long-term exposure to Tronto River water on juvenile Carassius auratus were evaluated with an integrated approach using xenoestrogens biomarkers, such as vitellogenin (VTG) and ER β-1 mRNA expression, and stress parameters (i.e., cortisol and glucose in the blood and glycogen in the liver). Treatment with Tronto River water did not induce VTG synthesis in fish and did not affect ER β-1 mRNA expression. Moreover, cortisol titers found in the plasma of fish exposed to Tronto River water were lower than those found in the control group. Regarding energy parameters, treatment with Tronto River water induced an increase in plasma glucose and a depletion of liver glycogen reserves. The effects of Tronto River water were studied in parallel with those of 4-NP and CdCl₂. The 4-NP at the dose of 22 μg/L induced the synthesis of peripheral vitellogenin and increase of ER β-1 titers; on the contrary, CdCl₂ exposure at the concentration of 22 μg/L did not induce significant changes on plasma VTG and/or hepatic ER β-1 levels. In addition, no significant changes in plasma cortisol levels in fish exposed to 4-NP or CdCl₂ were found. Fish exposed to CdCl₂ displayed liver glycogen depletion, but no significant increase in plasma glucose was observed. On the contrary, a 30-day exposure to 4-NP induced only a slight decrease of glycogen reserves without any changes in plasma glucose levels. In conclusion, our study demonstrated that long-term exposure of juvenile goldfish to the water of the Tronto River significantly affects both stress and energy parameters. There is evidence that pollutants, present in Tronto River water, were not able to induce xenoestrogenic effects but caused a functional impairment of the hypothalamum-pituitary-interrenal axis.
Electromagnetic fields are an assessed cause of prolonging free radicals lifespan. This study was carried out to investigate the influence of extremely low frequency electromagnetic fields on protein ...oxidation and on the 20S proteasome functionality, the complex responsible for the degradation of oxidized proteins. Caco 2 cells were exposed, for 24–72 hours, to 1 mT, 50 Hz electromagnetic fields. The treatment induced a time-dependent increase both in cell growth and in protein oxidation, more evident in the presence of TPA, while no changes in cell viability were detected. Exposing the cells to 50 Hz electromagnetic fields caused a global activation of the 20S proteasome catalytic components, particularly evident at 72 hours exposure and in the presence of TPA. The finding that EGCG, a natural antioxidant compound, counteracted the field-related pro-oxidant effects demonstrates that the increased proteasome activity was due to an enhancement in intracellular free radicals.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ