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Many-Body Correlation Effects on the xBjorken-Dependence of Cross Section Ratios off Nuclei for 1 <xBjorken<2

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Journal of Modern Physics 2022年第1期13卷 56-65页

作者： athanasios petridis Allen Barr Drew Fustin Department of Physics and Astronomy Drake University Des Moines USA

Many-body correlations in nuclei determine the behavior of Deep-Inelastic-Scattering (DIS) and Quasi-Elastic Scattering (QES) cross section ratios off heavy over light nuclei especially for xBjorken > 1, obtained at Jefferson Lab. They can be described in terms of quark-cluster formation in nuclei due to wave-function overlapping, manifesting itself when the momentum transfer is high so that the partonic degrees of freedom are resolved. In clusters (correlated nucleons) the quark and gluon momentum distributions are softer than in single nucleons and extend to xBjorken > 1. The cluster formation probabilities are computed using a network-defining algorithm in which the initial nucleon density is either standard Woods-Saxon or is input from lower energy data while the critical radius for nucleon merging is an adjustable parameter. The exact choice of critical radius depends on the specific nucleus and it is anti-correlated to the rescaling of the xBjorken needed for bound nucleons. The calculations show that there is a strong dependence of the cross section ratios on the xBjorken in agreement with the data and that four-body correlations are needed to explain the experimental results even in the range 1 xBjorken < 2. The dependence on the specific exponents of parton distributions in high-order clusters is weak.

关键词： Deep Inelastic Scattering Quasi-Elastic Scattering Short-Range Correlations Quark-Clusters

The Relativistic Time-Dependent Aharonov-Bohm Effect

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Journal of Modern Physics 2014年第16期5卷 1640-1651页

作者： athanasios N. petridis Zachary Kertzman Khinlay Win Department of Physics and Astronomy Drake University Des Moines USA

The relativistic Aharonov-Bohm (AB) effect is studied using the time-dependent Dirac equation. It is shown that if the initial electron distribution is a pulse it is possible to define time-dependent signals that dist... 详细信息

关键词： Aharonov-Bohm Effect Dirac Equation Time-Dependent Quantum Mechanics

Exact Analytical and Numerical Solutions to the Time-Dependent Schrödinger Equation for a One-Dimensional Potential Exhibiting Non-Exponential Decay at All Times

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Journal of Modern Physics 2010年第2期1卷 124-136页

作者： athanasios N. petridis Lawrence P. Staunton Jon Vermedahl Marshall Luban 不详

The departure at large times from exponential decay in the case of resonance wavefunctions is mathematically demonstrated. Then, exact, analytical solutions to the time-dependent Schr?dinger equation in one dimension are developed for a time-independent potential consisting of an infinite wall and a repulsive delta function. The exact solutions are obtained by means of a superposition of time-independent solutions spanning the given Hilbert space with appropriately chosen spectral functions for which the resulting integrals can be evaluated exactly. Square-integrability and the boundary conditions are satisfied. The simplest of the obtained solutions is presented and the probability for the particle to be found inside the potential well as a function of time is calculated. The system exhibits non-exponential decay for all times;the probability decreases at large times as . Other exact solutions found exhibit power law behavior at large times. The results are generalized to all normalizable solutions to this problem. Additionally, numerical solutions are obtained using the staggered leap-frog algorithm for select potentials exhibiting the prevalence of non-exponential decay at short times.

关键词： Non-Exponential Decay Exact Solutions

Contrast enhancement of vascular walls of intracranial high flow malformations in black blood MRI indicates high inflammatory activity

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Chinese Neurosurgical Journal 2018年第2期4卷 89-93页

作者： athanasios K.petridis Maxine Dibue-Adjei Jan F.Cornelius Marian Preetham Suresh Lan Li Marcel A.Kamp Yousef Abusabha Bernd Turowski Hans Jakob Steiger Rebecca May Department of Neurosurgery Heinrich Heine UniversityDuesseldorfGermany LivaNova Deutschland GmbH(a LivaNova PLC-owned subsidiary) Lindberghstr 25D-80939 MunichGermany Diagnostic and Interventional Neuroradiology Heinrich Heine UniversityDuesseldorfGermany Department of Neurosurgery Niederrhein HospitalDuisburgGermany

Background: There are controversies concerning the natural history of arteriovenous malformations (AVMs) in literature and it is not clear which AVMs should be treated and which should be just observed. Objective criteria beyond growth in serial MRIs or angiographies are needed. The use of black blood MRI is currently under investigation for evaluating the rupture risk of cerebral aneurysms, however its use for assessment of AVMs has yet to be evaluated. We therefore conducted a feasibility study on the application of black blood MRI (bbMRI) in AVMs to assess rupture risk. Methods: Retrospective study of 10 patients with intracranial AVMs and 4 patients with arteriovenous fistulas who received a black blood MRI before treatment. Results: AVM niduses (9/10) show contrast enhancement irrespective of rupture or size. All arteriovenous fistulas (4/4) were contrast enhancing irrespective of rupture. Conclusion: High flow malformations are in a permanent stage of inflammation which does not seem to allow conclusions on their rupture risk at the current stage. BbMRI is a feasible method of identifying inflammation in AVMs and arteriovenous fistulas. However, future prospective studies are needed to evaluate whether bbMRI contrast enhancement correlates with rupture risk.

关键词： Arteriovenous malformation Arteriovenous fistula Black blood MRI Inflammation

Cavernous brain malformations and their relation to black blood MRI in respect to vessel wall contrast enhancement

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Chinese Neurosurgical Journal 2018年第2期4卷 65-68页

作者： athanasios K.petridis Marian P.Suresh Jan F.Cornelius Richard Bostelmann Maxine Dibué-Adjei Lan Li Marcel A.Kamp Hans Jakob Steiger Bernd Turowski Rebecca May Department of Neurosurgery Heinrich Heine University DüsseldorfMoorenstr 540225 DüsseldorfGermany Diagnostic and Interventional Neuroradiology Heinrich Heine University DüsseldorfDüsseldorfGermany LivaNova Deutschland(a LivaNova PLC-owned subsidiary) Lindberghstr 2580939 MunichGermany

Background: Inflammatory responses are implicated as crucial patho-mechanisms of vascular brain malformations. Inflammation is suggested to be a key contributor to aneurysm rupture; however it is unclear whether inflammation contributes similarly to bleeding of cerebral cavernous malformations (CCMs). Black blood MRI is a sequence which identifies inflammation in blood vessel walls and in the present study is used to detect inflammatory response in CCMs. Methods: Fifteen patients with 17 CCMs treated in our department in 2017 were retrospectively analysed. All patients received black blood MRIs and the results were analysed in correlation with, size and bleeding of CCMs. Results: Size and bleeding status of CCMs did not correlate with contrast enhancement in the CCM wall. One of 3 patients with bleeding displayed contrast enhancement in black blood MRI, whereas the others had non enhancing lesions. Because of the small number of cases a statistical analysis was not performed. Conclusion: In this limited cohort, inflammatory reactions in CCMs could not be detected by black blood MRI suggesting that the level of inflammation is minimal in these lesions and those different patho-mechanisms play a more important role in the rupture of CCMs.

关键词： Cavernous malformations Inflammation Black blood MRI

The effect of platform switching on the levels of metal ion release from different implant–abutment couples

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International Journal of Oral Science 2016年第2期8卷 117-125页

作者： Ghada O Alrabeah Jonathan C Knowles Haralampos petridis Division of Biomaterials and Tissue Engineering UCL Eastman Dental Institute University College London London UK Prosthodontic Unit Department of Restorative Dentistry UCL Eastman Dental Institute University College London London UK

The improved peri-implant bone response demonstrated by platform switching may be the result of reduced amounts of metal ions released to the surrounding tissues. The aim of this study was to compare the levels of metal ions released from platform-matched and platform-switched implant-abutment couples as a result of accelerated corrosion. Thirty-six titanium alloy （Ti-6AI-4V） and cobalt-chrome alloy abutments were coupled with titanium cylinders forming either platform-switched or platform-matched groups （n = 6）. In addition, 18 unconnected samples served as controls. The specimens were subjected to accelerated corrosion by static immersion in 1% lactic acid for 1 week. The amount of metal ions ion of each test tube was measured using inductively coupled plasma mass spectrometry. Scanning electron microscope （SEM） images and energy dispersive spectroscopy X-ray analyses were performed pre- and post-immersion to assess corrosion at the interface. The platform-matched groups demonstrated higher ion release for vanadium, aluminium, cobalt, chrome, and molybdenum compared with the platform-switched groups （P〈 0.05）. Titanium was the highest element to be released regardless of abutment size or connection （P〈0.05）. SEM images showed pitting corrosion prominent on the outer borders of the implant and abutment platform surfaces. In conclusion, implant-abutment couples underwent an active corrosion process resulting in metal ions release into the surrounding environment. The highest amount of metal ions released was recorded for the platform-matched groups, suggesting that platform-switching concept has a positive effect in reducing the levels of metal ion release from the implant-abutment couples.

关键词： corrosion dental implants ion release peri-implant bone loss platform-switching titanium

The art of daily life

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The art of daily life

Transjugular intrahepatic portosystemic shunt with accidental diagnosis of persistence of the left superior vena cava

作者： Constantine petridis

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World Journal of Gastroenterology 2010年第9期16卷 1158-1160页

作者： Ioannis petridis Roberto Miraglia Gianluca Marrone Salvatore Gruttadauria Angelo Luca Giovanni Battista Vizzini Bruno Gridelli Department of Gastroenterology and Hepatology Mediterranean Institute for Transplantation and Advanced Specialized Therapies (IsMeTT)University of Pittsburgh Medical Center Department of Diagnostic and Interventional Radiology Mediterranean Institute for Transplantation and Advanced Specialized Therapies (IsMeTT)University of Pittsburgh Medical Center Department of Abdominal Surgery and Organ Transplantation Mediterranean Institute for Transplantation and Advanced Specialized Therapies (IsMeTT)University of Pittsburgh Medical Center

Transjugular intrahepatic portosystemic shunt (TIPSS) is considered a valid therapeutic option for the treatment of portal hypertension and its *** guidelines for this procedure have already been established on the basis of the normal vascular anatomy and of various technical radiological *** some few rare cases,diagnosis of a congenital vascular anomaly can be made accidentally by interventional radiologists,making the procedure of the TIPSS placement extremely difficult or in some cases technically *** report describes a rare vascular malformation characterized by the absence of the right superior vena cava and persistence of the left superior vena cava in a patient with a diagnosis of advanced liver cirrhosis who needed a TIPSS placement in order to control refractory ascites.

关键词： Left superior vena cava persistence Liver cirrhosis Refractory ascites Transjugular intrahepatic portosystemic shunt

Multimodal teaching,learning and training in virtual reality:a review and case study

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Virtual Reality & Intelligent Hardware 2020年第5期2卷 421-442页

作者： Stéphanie PHILIPPE Alexis DSOUCHET Petros LAMERAS Panagiotis petridis Julien CAPORAL Gildas COLDEBOEUF Hadrien DUZAN Department of Research ManzalabParisFrance Paragraph Laboratory Paris 8 UniversitySaint-DenisFrance School of Computing Electronics and MathematicsCoventry UniversityUnited Kingdom Aston Business School Aston UniversityUnited Kingdom Manzalab Singapore

It is becoming increasingly prevalent in digital learning research to encompass an array of different meanings,spaces,processes,and teaching strategies for discerning a global perspective on constructing the student learning *** is an emergent phenomenon that may influence how digital learning is designed,especially when employed in highly interactive and immersive learning environments such as Virtual Reality(VR).VR environments may aid students'efforts to be active learners through consciously attending to,and reflecting on,critique leveraging reflexivity and novel meaning-making most likely to lead to a conceptual *** paper employs eleven industrial case-studies to highlight the application of multimodal VR-based teaching and training as a pedagogically rich strategy that may be designed,mapped and visualized through distinct VR-design elements and *** outcomes of the use cases contribute to discern in-VR multimodal teaching as an emerging discourse that couples system design-based paradigms with embodied,situated and reflective praxis in spatial,emotional and temporal VR learning environments.

关键词： Virtual reality Multimodality Training Teaching and learning Semiotic resources