19 research outputs found

    Speckle pattern interferometry : vibration measurement based on a novel CMOS camera

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    A digital speckle pattern interferometer based on a novel custom complementary metaloxide- semiconductor (CMOS) array detector is described. The temporal evolution of the dynamic deformation of a test object is measured using inter-frame phase stepping. The flexibility of the CMOS detector is used to identify regions of interest with full-field time averaged measurements and then to interrogate those regions with time-resolved measurements sampled at up to 7 kHz. The maximum surface velocity that can be measured and the number of measurement points are limited by the frame rate and the data transfer rate of the detector. The custom sensor used in this work is a modulated light camera (MLC), whose pixel design is still based on the standard four transistor active pixel sensor (APS), but each pixel has four large independently shuttered capacitors that drastically boost the well capacity from that of the diode alone. Each capacitor represents a channel which has its own shutter switch and can either be operated independently or in tandem with others. The particular APS of this camera enables a novel approach in how the data are acquired and then processed. In this Thesis we demonstrate how, at a given frame rate and at a given number of measurement points, the data transfer rate of our system is increased if compared to the data transfer rate of a system using a standard approach. Moreover, under some assumptions, the gain in system bandwidth doesn’t entail any reduction in the maximum surface velocity that can be reliably measured with inter-frame phase stepping

    Assessing the pathogenicity of BRCA1/2 variants of unknown significance: Relevance and challenges for breast cancer precision medicine

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    IntroductionBreast cancer (BC) is the leading cause of cancer-related death in women worldwide. Pathogenic variants in BRCA1 and BRCA2 genes account for approximately 50% of all hereditary BC, with 60-80% of patients characterized by Triple Negative Breast Cancer (TNBC) at an early stage phenotype. The identification of a pathogenic BRCA1/2 variant has important and expanding roles in risk-reducing surgeries, treatment planning, and familial surveillance. Otherwise, finding unclassified Variants of Unknown Significance (VUS) limits the clinical utility of the molecular test, leading to an “imprecise medicine”.MethodsWe reported the explanatory example of the BRCA1 c.5057A>C, p.(His1686Pro) VUS identified in a patient with TNBC. We integrated data from family history and clinic-pathological evaluations, genetic analyses, and bioinformatics in silico investigations to evaluate the VUS classification.ResultsOur evaluation posed evidences for the pathogenicity significance of the investigated VUS: 1) association of the BRCA1 variant to cancer-affected members of the family; 2) absence of another high-risk mutation; 3) multiple indirect evidences derived from gene and protein structural analysis.DiscussionIn line with the ongoing efforts to uncertain variants classification, we speculated about the relevance of an in-depth assessment of pathogenicity of BRCA1/2 VUS for a personalized management of patients with BC. We underlined that the efficient integration of clinical data with the widest number of supporting molecular evidences should be adopted for the proper management of patients, with the final aim of effectively guide the best prognostic and therapeutic paths

    BRCA Mutation Status in Triple-Negative Breast Cancer Patients Treated with Neoadjuvant Chemotherapy: A Pivotal Role for Treatment Decision-Making

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    Simple Summary In this retrospective observational study, we evaluated data from patients with triple-negative breast cancer (TNBC) treated with neoadjuvant chemotherapy (NACT) in order to better define the impact of germline BRCA1/2 (gBRCA1/2) mutation status on outcomes in this patient population. Our results show that patients with BRCA1/2 mutation had a higher pathologic complete response (pCR) rate than non-mutated patients; nevertheless, the benefit was confirmed only in the subset of patients who received a platinum-based NACT. Furthermore, pCR was associated with improved Event Free Survival (EFS) and Overall Survival (OS), regardless of BRCA1/2 mutation status and type of NACT received. Long-term follow-up analyses are needed to further define the impact of gBRCA mutation status in patients with early-TNBC. Triple-negative breast cancer (TNBC) is characterized by earlier recurrence and shorter survival compared with other types of breast cancer. Moreover, approximately 15 to 25% of all TNBC patients harbor germline BRCA (gBRCA) 1/2 mutations, which confer a more aggressive phenotype. However, TNBC seems to be particularly sensitive to chemotherapy, the so-called 'triple negative paradox'. Therefore, Neoadjuvant chemotherapy (NACT) is currently considered the preferred approach for early-stage TNBC. BRCA status has also been studied as a predictive biomarker of response to platinum compounds. Although several randomized trials investigated the addition of carboplatin to standard NACT in early-stage TNBC, the role of BRCA status remains unclear. In this retrospective analysis, we evaluated data from 136 consecutive patients with Stage I-III TNBC who received standard NACT with or without the addition of carboplatin, in order to define clinical features and outcomes in BRCA 1/2 mutation carriers and non-carrier controls. Between January 2013 and February 2021, 67 (51.3%) out of 136 patients received a standard anthracyclines/taxane regimen and 69 (50.7%) patients received a platinum-containing chemotherapy regimen. Deleterious germline BRCA1 or BRCA2 mutations were identified in 39 (28.7%) patients. Overall, patients with deleterious gBRCA1/2 mutation have significantly higher pCR rate than non-carrier patients (23 [59%] of 39 vs. 33 [34%] of 97; p = 0.008). The benefit of harboring a gBRCA mutation was confirmed only in the subset of patients who received a platinum-based NACT (17 [65.4%] of 26 vs. 13 [30.2%] of 43; p = 0.005) while no differences were found in the platinum-free subgroup. Patients who achieved pCR after NACT had significantly better EFS (OR 4.5; 95% CI 1.9-10.7; p = 0.001) and OS (OR 3.3; 95% CI 1.3-8.9; p = 0.01) than patients who did not, regardless of BRCA1/2 mutation status and type of NACT received. Our results based on real-world evidence show that TNBC patients with the gBRCA1/2 mutation who received platinum-based NACT have a higher pCR rate than non-carrier patients, supporting the use of this chemotherapy regimen in this patient population. Long-term follow-up analyses are needed to further define the role of gBRCA mutation status on clinical outcomes in patients with early-TNBC

    Event reconstruction for KM3NeT/ORCA using convolutional neural networks

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    The KM3NeT research infrastructure is currently under construction at two locations in the Mediterranean Sea. The KM3NeT/ORCA water-Cherenkov neutrino detector off the French coast will instrument several megatons of seawater with photosensors. Its main objective is the determination of the neutrino mass ordering. This work aims at demonstrating the general applicability of deep convolutional neural networks to neutrino telescopes, using simulated datasets for the KM3NeT/ORCA detector as an example. To this end, the networks are employed to achieve reconstruction and classification tasks that constitute an alternative to the analysis pipeline presented for KM3NeT/ORCA in the KM3NeT Letter of Intent. They are used to infer event reconstruction estimates for the energy, the direction, and the interaction point of incident neutrinos. The spatial distribution of Cherenkov light generated by charged particles induced in neutrino interactions is classified as shower- or track-like, and the main background processes associated with the detection of atmospheric neutrinos are recognized. Performance comparisons to machine-learning classification and maximum-likelihood reconstruction algorithms previously developed for KM3NeT/ORCA are provided. It is shown that this application of deep convolutional neural networks to simulated datasets for a large-volume neutrino telescope yields competitive reconstruction results and performance improvements with respect to classical approaches

    Event reconstruction for KM3NeT/ORCA using convolutional neural networks

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    The KM3NeT research infrastructure is currently under construction at two locations in the Mediterranean Sea. The KM3NeT/ORCA water-Cherenkov neutrino de tector off the French coast will instrument several megatons of seawater with photosensors. Its main objective is the determination of the neutrino mass ordering. This work aims at demonstrating the general applicability of deep convolutional neural networks to neutrino telescopes, using simulated datasets for the KM3NeT/ORCA detector as an example. To this end, the networks are employed to achieve reconstruction and classification tasks that constitute an alternative to the analysis pipeline presented for KM3NeT/ORCA in the KM3NeT Letter of Intent. They are used to infer event reconstruction estimates for the energy, the direction, and the interaction point of incident neutrinos. The spatial distribution of Cherenkov light generated by charged particles induced in neutrino interactions is classified as shower-or track-like, and the main background processes associated with the detection of atmospheric neutrinos are recognized. Performance comparisons to machine-learning classification and maximum-likelihood reconstruction algorithms previously developed for KM3NeT/ORCA are provided. It is shown that this application of deep convolutional neural networks to simulated datasets for a large-volume neutrino telescope yields competitive reconstruction results and performance improvements with respect to classical approaches

    Study of an intrinsically safe infrastructure for training and research on nuclear technologies

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    Within European Partitioning & Transmutation research programs, infrastructures specifically dedicated to the study of fundamental reactor physics and engineering parameters of future fast-neutron-based reactors are very important, being some of these features not available in present zero-power prototypes. This presentation will illustrate the conceptual design of an Accelerator-Driven System with high safety standards, but ample flexibility for measurements. The design assumes as base option a 70MeV, 0.75mA proton cyclotron, as the one which will be installed at the INFN National Laboratory in Legnaro, Italy and a Beryllium target, with Helium gas as core coolant. Safety is guaranteed by limiting the thermal power to 200 kW, with a neutron multiplication coefficient around 0.94, loading the core with fuel containing Uranium enriched at 20% inserted in a solid-lead diffuser. The small decay heat can be passively removed by thermal radiation from the vessel. Such a system could be used to study, among others, some specific aspects of neutron diffusion in lead, beam-core coupling, target cooling and could serve as a training facility

    Insulin-like growth factor I (CA) repeats are associated with higher melanoma's Breslow index but not associated with the presence of the melanoma. A pilot study

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    Santonocito C, Paradisi A, Capizzi R, Concolino P, Lavieri MM, Silveri SL, Luca DD, Catrical\ue0 C, Carlo AD, Zuppi C, Ameglio F, Capoluongo E. Laboratory of Molecular Biology, Institute of Biochemistry & Clinical Biochemistry, Italy. BACKGROUND: IGF-I-(CA) repeats have been previously analysed in few types of cancer and the results, although discordant in different studies, showed possible associations between cancer and IGF-I(CA)(19) repeats. Aim of this pilot study was to detect a possible association between some of the IGF-I(CA) repeats and the presence of malignant melanoma and its Breslow index. METHODS: Two hundred patients affected with cutaneous malignant melanoma and 100 control healthy subjects were analysed for IGF-I(CA) repeats by fragment analysis sequencing and, partially, confirmed by direct sequencing. RESULTS: A significant association of IGF-I(CA)(19) repeats was observed with melanoma higher Breslow indices (P<0.001), while no association between melanoma patients and the different genotypes of IGF-I(CA) was found. The above mentioned association was confirmed after Bonferroni's correction for multiple comparisons and also by logistic regression analysis adjusted for age, sex and BMI variables. A slight, significant difference (P=0.03) was observed for serum IGF-I values in IGF-I(CA)(19)-positive or IGF-I(CA)(19)-negative subjects. DISCUSSION: The association observed for IGF-I(CA)(19) and malignant melanoma is in keeping with similar results obtained in prostate or breast cancers, suggesting that this type of repeat may be directly or indirectly important in controlling cancer induction and its severity. PMID: 18237549 [PubMed - as supplied by publisher

    Dynamical Dipole and Equation of State in N/Z Asymmetric Fusion Reactions

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    In heavy ion reactions, in the case of N/Z asymmetry between projectile and target, the process leading to complete fusion is expected to produce pre-equilibrium dipole γ-ray emission. It is generated during the charge equilibration process and it is known as Dynamical Dipole. A new measurement of the dynamical dipole emission was performed by studying 16O + 116Sn at 12 MeV/u. These data, together with those measured at 8.1 MeV/u and 15.6 MeV/u for the same reaction, provide the dependence on the Dynamical Dipole total emission yield with beam energy and they can be compared with theoretical expectations. The experimental results show a weak increase of the Dynamical Dipole total yield with beam energies and are in agreement with the prediction of a theoretical model based on the Boltzmann–Nordheim–Vlasov (BNV) approach. The measured trend with beam energy does not confirm the rise and fall behavior previously reported for the same fused compound but with a much higher dipole moment

    Study of an intrinsically safe infrastructure for training and research on nuclear technologies

    Get PDF
    Within European Partitioning & Transmutation research programs, infrastructures specifically dedicated to the study of fundamental reactor physics and engineering parameters of future fast-neutron-based reactors are very important, being some of these features not available in present zero-power prototypes. This presentation will illustrate the conceptual design of an Accelerator-Driven System with high safety standards, but ample flexibility for measurements. The design assumes as base option a 70MeV, 0.75mA proton cyclotron, as the one which will be installed at the INFN National Laboratory in Legnaro, Italy and a Beryllium target, with Helium gas as core coolant. Safety is guaranteed by limiting the thermal power to 200 kW, with a neutron multiplication coefficient around 0.94, loading the core with fuel containing Uranium enriched at 20% inserted in a solid-lead diffuser. The small decay heat can be passively removed by thermal radiation from the vessel. Such a system could be used to study, among others, some specific aspects of neutron diffusion in lead, beam-core coupling, target cooling and could serve as a training facility
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