17,281 research outputs found
Deep-Learning Based Analyses of Mammograms to Improve the Estimation of Breast Cancer Risk
No full textBreast cancer is the most commonly diagnosed cancer among women worldwide. Survival rates strongly depend on early diagnosis, and for this reason mammographic screening is performed in developed countries. New artificial intelligence-based techniques have the potential to include and quantify fibroglandular (or dense) parenchyma in breast cancer risk models
Breast density characterization through convolutional neural networks and first order statistical features
No full text3D Printing Materials for Physical Breast Phantoms: Monte Carlo Assessment and Experimental Validation
No full textThe aim of this work is to characterize 3D-printing materials to be used for breast physical phantoms in mammography and digital breast tomosynthesis QA procedures or research. Our approach involves both Monte Carlo (MC) calculations and experimental measurements. Using a GEANT4-based application, MC simulations are involved in order to compare transmission properties of the digital "standard breast", which is composed by the external skin layer and the breast tissue inside, with those of typical printable materials. Substitute materials for skin laver and breast tissue have been identified and a 3D-printed physical breast phantom has been derived. Finally, a comparison between MC results and experimental measurements has been performed with the Hologic Selenia (R) Dimensions (R) mammography unit using XR-QA2 radiochromic films
The Story of "Me" Contemporary American Autofiction
No full textCover -- Title Page -- Copyright Page -- Contents -- Acknowledgments -- Introduction -- 1. Masculinity, Whiteness, and Postmodern Self-Consciousness -- 2. Rage against the Dying of the Author -- 3. The New Journalism as the New Fiction -- 4. Trauma Autofiction, Dissociation, and the Authenticity of "Real" Experience -- 5. Memoir vs. Autofiction as the Story of Me vs. the Story of "Me" -- Coda -- Appendix -- Notes -- References -- IndexDescription based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
Dynamical density functional study of the multistep CO insertion into zirconium-carbon bonds anchored to a calix[4]arene moiety
No full textThe multistep migratory insertion reaction of CO into the zirconium-carbon bonds in [calix[4](OMe)(2)(O)(2)ZrMe2] has been investigated by means of both static and dynamic density functional calculations. A relatively stable facial CO complex has been observed with a negligible barrier for CO insertion into one of the Zr-Me bonds, leading to the formation of an eta (2)-acyl complex. The insertion of the residual alkyl group into the acyl moiety, leading to an eta (2)-bound acetone, has also been investigated, and a small energy barrier, 2.3 kcal/mol, has been found. Dynamics simulations have been performed on the [calix[4](OMe)(2)(O)(2)Zr(Me)(2)]-CO adduct in order to study the detailed features of the whole multistep insertion and show that the migratory insertion leads to the formation of an out-of-plane eta (2)-acyl complex, which is readily converted into the more stable eta (2)-acyl isomer within 1.5 ps. The subsequent methyl to acyl migration has been observed within 5 ps, leading to the formation of the eta (2)-bound acetone by a facial attack of the migrating methyl to the acyl carbon. A comparison with the migratory insertion of CO into the metal-alkyl bond in (Me)(2)Zr(Cp)(2) has been performed, showing substantial differences in the reactivity of the calix[4]arene and bis(cyclopentadienyl) substrates
A new method to evaluate the average absorbed dose in mammography and breast tomosynthesis
No full textDigital mammography represents the most sensitive technique to detect and diagnose breast cancer and is hence the preferred method for clinical and screening diagnostic tests. Nevertheless, the absorbed dose in a mammographic procedure can not be neglected even due to the highly radiosensitivity of the breast. In this work we developed a practical method to assess the average absorbed dose both in digital mammography and digital breast tomosynthesis. A new dose index is here proposed as an easily evaluable dosimetric quantity according to the requests of the European Directive 2013/59 EURATOM
Image Quality Comparison between Synthetic 2D Mammograms Obtained with 15º and 40º X-ray Tube Angular Range: A Quantitative Phantom Study
No full textIn this work we present an image quality comparison between synthesized mammograms (SMs) obtained from Digital Breast Tomosynthesis (DBT) acquisitions with 15 degrees (SM15) and 40 degrees (SM40) X-ray tube angular range. In fact, since wide-angle DBT is characterized by a better spatial resolution in depth but also by worse performance in detecting microcalcifications than narrow-angle DBT, an objective image quality analysis of SM images could be of pratical interest. Four phantoms were employed in this study and their images were acquired using an Amulet Innovality mammographic device. The image quality comparison was conducted by evaluating spatial resolution, contrast and noise properties of the images. Our results show that SM40 images are characterized by better spatial resolution performance than SMI5 in terms of Modulation Transfer Function but also by worse performance in the detection of low-contrast details. In fact, higher contrast-tonoise ratio values were obtained with SM15 than with SM40. Noise properties of the images were also investigated through the Noise Power Spectrum (NPS) calculation: no differences in NPS shapes were found in both modalities, while noise magnitude results significantly different. In addition, Signal-to-Noise Ratio (SNR) spatial distribution evaluation was assessed by computing SNR maps, in which different pattern were observed
Remember Me A Novella about Finding Our Way to the Cross
No full textShades of Light.Cover -- Title Page -- Copyright -- Dedication Page -- Contents -- 1 The Word Became Flesh -- 2 The Gift of Myrrh -- 3 Taking the Cup -- 4 With a Kiss -- 5 Awakened -- 6 Accused -- 7 Bearing the Cross -- 8 Lament -- 9 Stripped -- 10 Pierced -- 11 It Is Finished -- 12 Into Your Hands -- 13 Buried -- 14 Risen -- Epilogue -- Journey to the Cross -- Acknowledgments -- Also Available -- Praise for Remember Me -- About the Author -- More Titles from InterVarsity PressShades of Light.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
Cellular neural network approach to a class of communication problems
No full textIn this paper me discuss the design of a cellular neural network (CNN) to solve a class of optimization problems of importance for communication networks. The CNN optimization capabilities are exploited to implement an efficient cell scheduling algorithm in a fast packet switching fabric. The neural-based switching fabric maximizes the cell throughput and, at the same time, it is able to meet a variety of quality of service (QoS) requirements by optimizing a suitable function of the switching delay and priority of the cells. We also show that the CNN approach has advantages with respect to that based on Hopfield neural networks (HNN's) to solve the considered class of optimization problems. In particular, we exploit existing techniques to design CNN's with a prescribed set of stable binary equilibrium points as a basic tool to suppress spurious responses and, hence to optimize the neural switching fabric performance
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