513 research outputs found
Time-dependent geomagnetic cutoff estimation along the ISS orbit
In this contribution we present the calculation of a realistic timedependent geomagnetic cutoff along the International Space Station orbit, at about 400km above the Earth’s surface. For this work the Tsyganenko05 and IGRF models have been employed, including the temporal variation of the external component of the geomagnetic field due to the solar activity. The technique and its results will be
discussed, as well as the relevance of this study to distinguish galactic cosmic rays from trapped secondary components in the geomagnetic field
Status of the measurement of the nuclear components in cosmic rays with the AMS-02 experiment
The Alpha Magnetic Spectrometer (AMS-02) is a large-acceptance (0.45 m2sr) magnetic spectrometer operating on board the International Space Station since May 2011. One of the main scientific objectives of the mission is the measurement of the nuclei fluxes in cosmic rays (CR). The identification of nuclei is achieved by the combination of independent measurements of the absolute charge, provided by different sub-detectors: the Silicon Tracker, the Time-of-Flight system (TOF), the Ring Imaging Cherenkov Counter (RICH), the Transition Radiation Detector (TRD) and the Electromagnetic Calorimeter (ECAL). In this contribution the results of nuclei fluxes already shown by the AMS collaboration are presented
Precision measurement of the lithium flux in cosmic rays with the AMS-02 detector
The Alpha Magnetic Spectrometer (AMS-02) is a magnetic spectrometer designed for the precision study of cosmic ray (CR) composition and energy spectrum from GeV to TeV. It was installed on May 2011 on the International Space Station and is continuously taking data since then. Using the high acceptance (0.45 m2sr) and long exposure time, AMS-02 is able to measure the flux of numerous CR species and to study their spectral index variation as a function of energy. In particular, lithium nuclei in cosmic rays are produced by the spallation of heavier ions that collide with interstellar nuclei. For this reason, the abundance of lithium in CRs is a useful tool to model the propagation of CRs in the Galaxy. In this contribution the precision measurement of the lithium flux from 1.9 GV to 3 TV, based on 1.9 million events collected by AMS-02 detector in five years is discusse
Dbl oncogene expression in MCF-10 A epithelial cells disrupts mammary acinar architecture, induces EMT and angiogenic factor secretion.
The proteins of the Dbl family are guanine nucleotide exchange factors (GEFs) of Rho GTPases and are known to be involved in cell growth regulation. Alterations of the normal function of these proteins lead to pathological processes such as developmental disorders, neoplastic transformation, and tumor metastasis. We have previously demonstrated that expression of Dbl oncogene in lens epithelial cells modulates genes encoding proteins involved in epithelial-mesenchymal-transition (EMT) and induces angiogenesis in the lens. Our present study was undertaken to investigate the role of Dbl oncogene in epithelial cells transformation, providing new insights into carcinoma progression. To assess how Dbl oncogene can modulate EMT, cell migration, morphogenesis, and expression of pro-apoptotic and angiogenic factors we utilized bi- and three-dimensional cultures of MCF-10░A cells. We show that upon Dbl expression MCF-10░A cells undergo EMT. In addition, we found that Dbl overexpression sustain
Linomide blocks angiogenesis by breast carcinoma vascular endothelial growth factor transfectants.
The blocking of angiogenesis provides a novel therapeutic target to inhibit tumour spreading. In this study, we investigated the effect of linomide on angiogenesis induced in vivo by highly angiogenic breast carcinoma cells. The rabbit cornea was used to assess neovascular growth in the absence of a tumour mass. MCF-7 cells stably transfected with the cDNA encoding for vascular endothelial growth factor 121 (VEGF121) (V12 clone) were used to elicit a potent VEGF-dependent corneal angiogenesis. After tumour cell implant, albino rabbits received 100 mg kg(-1) day(-1) linomide for 5 consecutive days. Daily observation of neovascular progression indicated that linomide blocked angiogenesis. The antiangiogenic effect of linomide was apparent within 48 h from the beginning of the treatment and was both angiosuppressive and angiostatic. The block of neovascular growth lasted over 10 days from treatment suspension, and preformed vessels, which had regressed, remained dormant, suggesting the persistence of unfavourable conditions for capillary progression. Linomide (50-200 microg ml[-1]) was not cytotoxic in vitro on resting capillary endothelial cells but blocked endothelial cell replication induced by VEGF. Our data indicate that linomide can efficiently and persistently block VEGF-dependent angiogenesis in vivo in the absence of a growing tumour mass. These data suggest that linomide could be a chemopreventive drug in breast cancer patients and a valuable tool in clinical settings in which metastatic spreading occurs in the absence of a detectable tumour mass
Microbial Safety of Black Summer Truffle Collected from Sicily and Umbria Regions, Italy
Background: Tuber aestivum Vittad., known as black summer truffle, represents
high-value food especially used as garnishment in nouvelle cuisine. The aim of this study
was to investigate on the viable microbial populations associated with T. aestivum
ascomata collected in different sites of Sicily and one locality of Umbria (Italy).
Methods: The ripe ascomata of black summer truffles were collected from Central Italy.
Cell densities of spoilage bacteria, fecal indicators, potential pathogens, yeasts, and molds
were analyzed. Statistical analysis was conducted with XLSTAT software.
Results: The microbiological counts of truffles ranged between 6.00 and 9.63 log Colony
Forming Unit (CFU)/g for total mesophilic count and between 6.18 and 8.55 log CFU/g
for total psychrotrophic count; pseudomonads were in the range 6.98-9.28 log CFU/g.
Listeria spp. and coagulase-positive streptococci detected in no samples. Coagulasenegative
streptococci were found in some samples with 2.11-4.76 log CFU/g levels.
Yeasts and filamentous fungi were detected at consistent levels of 3.60-7.81 log CFU/g.
Significant differences (p<0.01) were found between samples and also for all microbial
groups.
Conclusion: This study evidenced that the common brushing procedure applied for
preparation of truffles is not sufficient to eliminate microbial risks for consumers. The
application of an efficient decontamination treatment is strongly suggested before
consumption of fresh truffles
Sustained virologic response to direct-acting antiviral agents predicts better outcomes in hepatitis C virus-infected patients: A retrospective study
Direct-acting antiviral agents (DAAs) are extremely effective in eradicating hepatitis C virus (HCV) in chronically infected patients. However, the protective role of the sustained virologic response (SVR) achieved by second- and third-generation DAAs against the onset of hepatocellular carcinoma (HCC) and mortality is less well established
Effects of Monacolin K in Nondiabetic Patients with NAFLD: A Pilot Study
Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver condition with significant risk of progression to steatohepatitis and cirrhosis. Therapeutic strategies in NAFLD include lifestyle changes mainly related to dietary interventions and use of drugs or nutritional components that could improve plasma lipid profiles and insulin sensitivity and decrease the local inflammatory response. In this study, we tested the effects of monacolin K, an inhibitor of HMCoA reductase. In a prospective, uncontrolled, open study, we treated 24 patients with NAFLD and mild hypercholesterolemia with 10 mg/day of monacolin K. At baseline and after 26 weeks, we measured in plasma liver tests, lipids, malondialdehyde, and oxidized glutathione, and assessed biochemical steatosis scores, liver elastography, and body composition with bioimpedance analysis. Monacolin K significantly reduced plasma alanine aminotransferase, cholesterol, triglycerides and the homeostatic model assessment (HOMA) index that indicated improved insulin sensitivity. No significant changes were found in body fat mass and visceral fat, nor in liver elastography, while the fatty liver index (FLI) was significantly decreased. Plasma levels of both malondialdehyde and oxidized glutathione were markedly reduced by monacolin K treatment, suggesting a reduction in oxidative stress and lipid peroxidation. In summary, this pilot study suggests possible benefits of monacolin K use in NAFLD patients that could be linked to a reduction in oxidative stress. This hypothesis should be further investigated in future studies
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