15 research outputs found

    Simulation of a trust and reputation based mitigation protocol for a black hole style attack on VANETs

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    From a security standpoint, VANETs (Vehicular ad hoc Networks) are vulnerable to attacks by malicious users, due to the decentralized and open nature of the wireless system. For many of these kinds of attacks detection is unfeasible, thus making it hard to produce security. Despite their characterization as dynamically reconfigurable networks, it is nonetheless essential to identify topology and population properties that can optimise mitigation protocols’ deployment. In this paper, we provide an algorithmic definition and simulation of a trust and mitigation based protocol to contain a Black Hole style attack on a VANET. We experimentally show its optimal working conditions: total connectivity, followed by a random network; connection to external networks; early deployment of the protocol and ranking of the message. We compare results with those of existing protocols and future work shall focus on repeated broadcasting, opportunistic message forwarding and testing on real data

    Type 2 diabetes and cancer: problems and suggestions for best patient management

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    Diabetes and cancer are widespread worldwide and the number of subjects presenting both diseases increased over the years. The management of cancer patients having diabetes represents a challenge not only because of the complexity and heterogeneity of these pathologies but also for the lack of standardised clinical guidelines. The diagnosis of cancer is traumatizing and monopolizes the attention of both patients and caregivers. Thus, pre-existent or new-onset diabetes can be overshadowed thus increasing the risk for short- and long-term adverse events. Moreover, drugs used for each disease can interfere with the clinical course of the concomitant disease, making challenging the management of these patients. Over the years, this issue has become more relevant because of the increased patients' life expectancy due to the improved efficacy of diabetes and cancer therapies. The purpose of this review is to highlight what is known and what should be taken into consideration to optimise the clinical management of patients with diabetes and cancer. Due to the complexity of these diseases, a multidisciplinary, shared approach, including all the protagonists involved, is necessary to improve patients' quality of life and lifespan

    Cortico-Subcortical Metabolic Changes in Aging Brain

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    Aim: to investigate the effects of aging on brain glucose consumption on a population of healthy subjects.Materials and methods: 102 chemotherapy-naïve subjects (56 men, 46 women; mean age 57±16 years old; age range 20-89 years) undergoing a whole body 18F FDG PET/CT and found to be completely negative for various diseases in both PET/CT and contrast enhanced CT (performed contextually to PET/CT scan) were enrolled in the study. Age-related changes in brain 18F-FDG uptake were analysed by statistical parametric mapping (SPM8).Results: aging is related to a reduction of brain glucose consumption in right medial frontal gyrus (BA9) and anterior cingulate cortex (BA32) and to an increased 18F-FDG uptake in right sub-cortical structures (lentiform nucleus, claustrum) and in cerebellum bilaterally.Conclusions: The results of our study suggest that a reduced functioning of ACC and medial PFC occur in the elderly. An increased activation of the cerebellum, lentiform nucleus and claustrummay represent a compensatory mechanism, possibly involved in cognitive decline

    Cortico-Subcortical Metabolic Changes in Aging Brain: A 18F FDG PET/CT Study

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    Aim: to investigate the effects of aging on brain glucose consumption on a population of healthy subjects. Materials and methods: 102 chemotherapy-naïve subjects (56 men, 46 women; mean age 57±16 years old; age range 20-89 years) undergoing a whole body 18F FDG PET/CT and found to be completely negative for various diseases in both PET/CT and contrast enhanced CT (performed contextually to PET/CT scan) were enrolled in the study. Age-related changes in brain 18F-FDG uptake were analysed by statistical parametric mapping (SPM8). Results: aging is related to a reduction of brain glucose consumption in right medial frontal gyrus (BA9) and anterior cingulate cortex (BA32) and to an increased 18F-FDG uptake in right sub-cortical structures (lentiform nucleus, claustrum) and in cerebellum bilaterally. Conclusions: The results of our study suggest that a reduced functioning of ACC and medial PFC occur in the elderly. An increased activation of the cerebellum, lentiform nucleus and claustrummay represent a compensatory mechanism, possibly involved in cognitive decline

    Comparison between early-onset and late-onset alzheimer's disease patients with amnestic presentation: CSF and 18F-FDG PET study

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    BACKGROUND/AIMS To investigate the differences in brain glucose consumption between patients with early onset of Alzheimer's disease (EOAD, aged ≤65 years) and patients with late onset of Alzheimer's disease (LOAD, aged >65 years). METHODS Differences in brain glucose consumption between the groups have been evaluated by means of Statistical Parametric Mapping version 8, with the use of age, sex, Mini-Mental State Examination and cerebrospinal fluid values of AΒ1-42, phosphorylated Tau and total Tau as covariates in the comparison between EOAD and LOAD. RESULTS As compared to LOAD, EOAD patients showed a significant decrease in glucose consumption in a wide portion of the left parietal lobe (BA7, BA31 and BA40). No significant differences were obtained when subtracting the EOAD from the LOAD group. CONCLUSIONS The results of our study show that patients with EOAD show a different metabolic pattern as compared to those with LOAD that mainly involves the left parietal lobe

    Biparametric versus multiparametric mri with non-endorectal coil at 3t in the detection and localization of prostate cancer

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    Aim: To assess the sensitivity of biparametric magnetic resonance imaging (bpMRI) with non-endorectal coil in the detection and localization of index (dominant) and nonindex lesions in patients suspected of having prostate cancer. Patients and Methods: We carried-out a retrospective analysis of multiparametric MRI (mpMRI) of 41 patients who underwent radical prostatectomy. Results of MRI for detection and localization of index and non-index lesions were correlated with those of histology. Results: No statistically significant difference in size was seen between tumor lesion at histology and index lesion at MRI. In 41 patients, a total of 131 tumors were identified at histology, while bpMRI (T2-weighted and diffusionweighted MRI) approach detected 181 lesions. bpMRI gave 27.6% false-positives and 3.3% false-negatives. Sensitivity in lesion detection by bpMRI increased with lesion size assuming high values for lesions 10 mm. For bpMRI and mpMRI, the sensitivity for detecting index lesions was the same and equal: 100% in the peripheral zone 97.6% and 94.7% in the entire prostate and transitional zone, respectively. Conclusion: bpMRI can be used alternatively to mpMRI to detect and localize index prostate cancer

    Is contrast enhancement needed for diagnostic prostate MRI?

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    Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) provides clinical guidelines for multiparametric magnetic resonance imaging (mpMRI) [T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)] of prostate. However, DCE-MRI seems to show a limited contribution in prostate cancer (PCa) detection and management. In our experience, DCE-MRI, did not show significant change in diagnostic performance in addition to DWI and T2WI [biparametric MRI (bpMRI)] which represent the predominant sequences to detect suspected lesions in peripheral and transitional zone (TZ). In this article we reviewed the role of DCE-MRI also indicating the potential contribute of bpMRI approach (T2WI and DWI) and lesion volume evaluation in the diagnosis and management of suspected PCa

    Functional correlates of t-Tau, p-Tau and Aβ<inf>1-42</inf> amyloid cerebrospinal fluid levels in Alzheimer's disease: A <sup>18</sup>F-FDG PET/CT study

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    Abstract AIM: The aim of the study was to investigate the relationships between cerebrospinal fluid (CSF) levels of t-Tau, p-Tau and amyloid-β (Aβ₁₋₄₂) amyloid peptide and fluorine-18 fluorodeoxyglucose (¹⁸F-FDG) brain distribution in a group of patients with Alzheimer's disease. MATERIALS AND METHODS: The study included 81 newly diagnosed Alzheimer's disease patients according to the NINCDS-ADRDA criteria. The mean (±SD) age of the patients was 70 (±6) years; 44 were male and 37 were female. All patients underwent a CSF assay and MRI before ¹⁸F-FDG PET scanning. The relationships were evaluated by means of statistical parametric mapping (SPM8). RESULTS: Increased t-Tau CSF levels were related to reduced glucose consumption in a wide portion of the right frontal lobe [Brodmann area (BA 47)] and limbic lobe bilaterally (BA 31,32), whereas no areas of increased ¹⁸F-FDG uptake related to t-Tau levels were detected. Elevated p-Tau concentrations in CSF were related to increased glucose consumption in both the right and the left limbic lobe and in the left frontal lobe (BA 32 and 8). We did not find any specific cortical area of reduced glucose consumption being related to low levels of Aβ₁₋₄₂ in CSF, whereas a spawn of ¹⁸F-FDG uptake was detectable in BA 18,19 and in the right cerebellum. CONCLUSION: The results of our study suggest that reduced Aβ₁₋₄₂ concentrations in CSF are related to a wide cortical dysfunction, whereas t-Tau and p-Tau are related to more selective cortical metabolic patterns that mainly involve the cingulate cortex

    Functional correlates of microglial and astrocytic activity in symptomatic sporadic Alzheimer's disease: a CSF/18F-FDG-PET study

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    Glial and microglial cells contribute to brain glucose consumption and could actively participate in shaping patterns of brain hypometabolism. Here, we aimed to investigate the association between F-18-fluorodeoxyglucose (F-18-FDG) uptake and markers of microglial and astrocytic activity in a cohort of patients with Alzheimer's Disease (AD). We dosed cerebrospinal fluid (CSF) levels of soluble Triggering Receptor Expressed on Myeloid cells (sTREM2), Glial Fibrillary Acidic Protein (GFAP), a marker of reactive astrogliosis, and beta-S100, a calcium-binding protein associated with a neurotoxic astrocytic profile. No associations were found between sTREM-2 and 18F-FDG uptake. Instead, F-18-FDG uptake was associated negatively with CSF beta-S100 in the left supramarginal gyrus, inferior parietal lobe and middle temporal gyrus (Brodmann Areas (BA) 21 and 40). Increased beta-S100 levels could negatively regulate neuronal activity in the temporo-parietal cortex to prevent damage associated with AD hyperactivity, or rather they could reflect neurotoxic astrocytic activation contributing to AD progression in key strategic areas. We also identified a trend of positive association of F-18-FDG uptake with CSF GFAP in the right fronto-medial and precentral gyri (BA 6, 9 and 11), which has been reported in early AD and could either be persisting as an epiphenomenon tied to disease progression or be specifically aimed at preserving functions in the frontal cortex. Overall, CSF markers of astrogliosis seem to correlate with cortical glucose uptake in symptomatic sporadic AD, highlighting the role of astrocytes in shaping regional hypometabolism and possibly clinical presentation
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