3,886 research outputs found
Search for new physics with same-sign isolated dilepton events in CMS
An inclusive search for the presence of new physics in events with two isolated same-sign leptons, using the first 4.98 fbâ1 of CMS data taken in 2011 is presented. The topology is sensitive to many models beyond the standard model like supersymmetric models, extra dimensions, heavy Majorana neutrinos and doublecharged Higgs. No excess of data with respect the Standard Model predictions is seen and the results are interpreted as limits on the parameters of the CMSSM model
Search for the Standard Model Higgs boson decaying into two photons with the CMS experiment
With the discovery of a Higgs boson, the standard model (SM) of particle physics has been successfully proved giving an answer to the origin of the masses issue, through the electroweak symmetry breaking mechanism. The Higgs
decaying to two photons is presented. Although this process has a low branching ratio, it provides a clean final state topology, with a peak that can be observed over the background. The analysis is performed using 2011 and 2012 datasets recorded by the the CMS experiment [1] from pp collisions at centre of mass energies of 7TeV (5.1/fb) and 8TeV (19.6/fb) and shows the presence of a new boson with a mass of about 125 GeV
Cancer-Associated Thrombosis in Cirrhotic Patients with Hepatocellular Carcinoma.
It is common knowledge that cancer patients are more prone to develop venous thromboembolic complications (VTE). It is therefore not surprising that patients with hepatocellular carcinoma (HCC) present with a significant risk of VTE, with the portal vein being the most frequent site (PVT). However, patients with HCC are peculiar as both cancer and liver cirrhosis are conditions that can perturb the hemostatic balance towards a prothrombotic state. Because HCC-related hypercoagulability is not clarified at all, the aim of the present review is to summarize the currently available knowledge on epidemiology and pathogenesis of non-malignant thrombotic complications in patients with liver cirrhosis and HCC. They are at increased risk to develop both PVT and non-splanchnic VTE, indicating that both local and systemic factors can foster the development of site-specific thrombosis. Recent studies have suggested multiple and often interrelated mechanisms through which HCC can tip the hemostatic balance of liver cirrhosis towards hypercoagulability. Described mechanisms include increased fibrinogen concentration/polymerization, thrombocytosis, and release of tissue factor-expressing extracellular vesicles. Currently, there are no specific guidelines on the use of thromboprophylaxis in this unique population. There is the urgent need of prospective studies assessing which patients have the highest prothrombotic profile and would therefore benefit from early thromboprophylaxis
A robust adaptive algebraic multigrid linear solver for structural mechanics
The numerical simulation of structural mechanics applications via finite
elements usually requires the solution of large-size and ill-conditioned linear
systems, especially when accurate results are sought for derived variables
interpolated with lower order functions, like stress or deformation fields.
Such task represents the most time-consuming kernel in commercial simulators;
thus, it is of significant interest the development of robust and efficient
linear solvers for such applications. In this context, direct solvers, which
are based on LU factorization techniques, are often used due to their
robustness and easy setup; however, they can reach only superlinear complexity,
in the best case, thus, have limited applicability depending on the problem
size. On the other hand, iterative solvers based on algebraic multigrid (AMG)
preconditioners can reach up to linear complexity for sufficiently regular
problems but do not always converge and require more knowledge from the user
for an efficient setup. In this work, we present an adaptive AMG method
specifically designed to improve its usability and efficiency in the solution
of structural problems. We show numerical results for several practical
applications with millions of unknowns and compare our method with two
state-of-the-art linear solvers proving its efficiency and robustness.Comment: 50 pages, 16 figures, submitted to CMAM
Digital Integrator for Fast Accurate Measurement of Magnetic Flux by Rotating Coils
A fast digital integrator (FDI) with dynamic accuracy and a trigger frequency higher than those of a portable digital integrator (PDI), which is a state-of-the-art instrument for magnetic measurements based on rotating coils, was developed for analyzing superconducting magnets in particle accelerators. Results of static and dynamic metrological characterization show how the FDI prototype is already capable of overcoming the dynamic performance of PDI as well as covering operating regions that used to be inaccessibl
Performance Analysis of a Fast Digital Integrator for Magnetic Field Measurements at CERN
A Fast Digital Integrator (FDI) has been designed at CERN for increasing performance of state-of-art instruments analyzing superconducting magnets in particle accelerators. In particular, in flux measurement, a bandwidth up to 50-100 kHz and an accuracy of 10 ppm has to be targeted. In this paper, basic concepts and architecture of the developed FDI are highlighted. Numerical metrological analysis of the instrument performance is shown, by focusing both on deterministic errors and on uncertainty in time and amplitude domains
Thyroid ultrasonography reporting: consensus of Italian Thyroid Association (AIT), Italian Society of Endocrinology (SIE), Italian Society of Ultrasonography in Medicine and Biology (SIUMB) and Ultrasound Chapter of Italian Society of Medical Radiology (SIRM)
Thyroid ultrasonography (US) is the gold standard for thyroid imaging and its widespread use is due to an optimal spatial resolution for superficial anatomic structures, a low cost and the lack of health risks. Thyroid US is a pivotal tool for the diagnosis and follow-up of autoimmune thyroid diseases, for assessing nodule size and echostructure and defining the risk of malignancy in thyroid nodules. The main limitation of US is the poor reproducibility, due to the variable experience of the operators and the different performance and settings of the equipments. Aim of this consensus statement is to standardize the report of thyroid US through the definition of common minimum requirements and a correct terminology. US patterns of autoimmune thyroid diseases are defined. US signs of malignancy in thyroid nodules are classified and scored in each nodule. We also propose a simplified nodule risk stratification, based on the predictive value of each US sign, classified and scored according to the strength of association with malignancy, but also to the estimated reproducibility among different operators
Metrological Characterisation of a Fast Digital Integrator for Magnetic Measurements at CERN
A Fast Digital Integrator (FDI) was designed to satisfy new more demanding requirements of dynamic accuracy and trigger frequency in magnetic measurements based on rotating coil systems for analyzing superconducting magnets in particle accelerators. In particular, in flux measurement, a bandwidth up to 50-100 kHz and a dynamic accuracy of 10ĂÂ ppm are targeted. In this paper, results of static and dynamic metrological characterization of the FDI prototype and of the Portable Digital Integrator (PDI), heavely used at CERN and in many sub-nuclear laboratories, are compared. Preliminary results show how the initial prototype of FDI is already capable of both overcoming dynamic performance of PDI and covering operating regions inaccessible before
Thyroid nodules treated with percutaneous radiofrequency thermal ablation: a comparative study
Percutaneous radiofrequency thermal ablation (RTA) was reported as an effective tool for the management of thyroid nodules (TNs). The aim of this study was to investigate the effects of RTA and to establish whether they were treatment-related by comparison with a matched, untreated control group
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