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Has the time been reached for pseudopolyps to be re-enrolled in endoscopic inflammatory bowel disease scores?

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World Journal of Gastrointestinal Endoscopy 2019年第6期11卷 424-426页

作者： dimitrios s politis Konstantinos H Katsanos Konstantinos Papamichael Maria saridi Eleni Albani dimitrios K Christodoulou Department of Gastroenterology University Hospital of IoanninaFaculty of MedicineSchool of Health SciencesUniversity of IoanninaIoannina 45110Greece Center for Inflammatory Bowel Diseases Division of GastroenterologyBeth-Israel Deaconess Medical CenterHarvard Medical SchoolBostonMA 02215United States General Hospital of Corinth Department of Social and Educational PolicyUniversity of PeloponneseCorinth 20100Greece Department of Nursing TEI of Western GreecePatra 26334Greece

Patients with inflammatory bowel diseases (IBD) represent heterogeneous groups with different characteristics and different clinical course. A great deal of effort is made to discover proxies for more severe disease needing more intense treatment and early intervention to gain the maximum therapeutic benefit. Endoscopy remains an invaluable method in assessment of patients with IBD. Pseudopolyps are often encountered during endoscopy and, although they are a well described entity, their presence is of unclear importance. In one of our recent studies and in conjunction with one study with a large cohort of patients with IBD and pseudopolyps, patients with pseudopolyps were found to face a higher inflammatory burden in terms of receiving more intense biological treatment. This letter comes as a comment and proposition regarding the concept of reevaluation of pseudopolyps as a promising marker in IBD scores.

关键词： Pseudopolyps Inflammatory bowel diseases Treatment escalation Endoscopic scores

Extending the decision-making process during yellow phase from human drivers to autonomous vehicles:A microsimulation study with safety considerations

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第2期11卷 362-379页

作者： Efthymis Papadopoulos Anastasia Nikolaidou Emmanouil Lilis Ioannis politis Panagiotis Papaioannou Transport Engineering Laboratory School of Civil EngineeringFaculty of EngineeringAristotle University of ThessalonikiThessaloniki 54124Greece

One of the main factors affecting the safety of signalised intersections is the stop/go behaviour during the yellow *** previous research has exhaustively examined drivers’stop/go decision-making,the expected autonomous vehicles’(AVs’)stop/go behaviour has not yet been thoroughly *** a series of simulation experiments developed for conventional and autonomous vehicles using different carfollowing,lane-changing,lateral placement and stop/go model parameter values,we examine here whether the default VIssIM stop/go parameter values can adequately replicate the observed drivers’behaviour at the considered intersection and assess the suitability of using the currently available options,albeit referring to human drivers,to simulate the expected stop/go behaviour of *** also propose a policy framework for determining the desired behaviour of AVs in yellow interval,which is integrated into an AVs logic and achieved in the last simulation to explore the effect of automation on the stop/go outcome and,hence,on the safety level of signalised *** data analysis and modeling techniques were used for the formulation of certain scenarios,including binary choice *** default stop/go parameter values were found unfit to replicate the observed stop/go behaviour and subjected to *** to the currently available options,the proposed AVs logic proved to produce the most accurate results,in terms of the stop/go simulation *** the impact of automation on the stop/go outcome,the simulation experiments showed that AVs preferred a more conservative behaviour in favor of road safety,as indicated by the significant reduction(≈15%)in the number of vehicles crossing the stop line during the yellow light and zero instances of red light ***,compared to the conservative drivers represented by the default stop/go parameter values,AVs preferred a more rational behaviour in favor of intersection capacit

关键词： Driver behaviour AVs behaviour signalised intersection Choice model Micro-simulation Policy framework

Interactive mechanism and friction modelling of transient tribological phenomena in metal forming processes: A review

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Friction 2024年第3期12卷 375-395页

作者： Xiao YANG Heli LIU Lemeng ZHANG Yiran HU Denis J.politis Mohammad M.GHARBI Liliang WANG Department of Mechanical Engineering Imperial College LondonLondon SW72AZUK Department of Mechanical and Manufacturing Engineering University of CyprusNicosia 1678Cyprus Quaker Houghton Deutschland GmbH Dortmund 44319Germany

The accurate representation of tribological boundary conditions at the tool–workpiece interface is crucial for analysis and optimization of formability,material flow,and surface quality of components during metal forming *** has been found that these tribological conditions vary spatially and historically with process parameters and contact *** time-dependent tribological behaviours are also known as transient tribological phenomena,which are widely observed during forming processes and many other manufacturing application ***,constant friction values are usually assigned to represent complex and dynamic interfacial conditions,which would introduce deviations in the relevant *** this paper,transient tribological phenomena and the contemporary understanding of the interaction between friction and wear are reviewed,and it has been found that these phenomena are induced by the transitions of friction mechanisms and highly dependent on complex loading conditions at the *** modelling techniques for transient behaviours for metal forming applications are also *** accurately describe the evolutionary friction values and corresponding wear during forming,the advanced interactive friction modelling has been established for different application scenarios,including lubricated condition,dry sliding condition(metal-on-metal contact),and coated system.

关键词： transient tribological phenomena interactive friction mechanism modelling techniques metal forming

Methological Approaches of seminal Importance for synergetic Education and social and solidarity Economy in Promoting Creativity and Innovation

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sino-Us English Teaching 2018年第2期15卷 70-86页

作者： Panagiota Vathi dimitrios Kapogiannis Vaggelis politis-stergiou Technological Institution of Western Greece Patras University Greece

This paper examines whether and in what ways the education system and the pedagogical culture particularly prevailing in Higher Education could be enriched with an alternative pedagogical model. A model that is differentiated from the prevalent pedagogical concepts is inspired by values and principles that form the core of a synergetic education and a social and solidarity economy. From an epistemological perspective, ＂ssociationnisme＂ that social and solidarity economy promotes is at stake and education must play an important role. The paper also examines the attitude of students towards such a perspective, mainly through exploring the current options as well as its potential expansion thereof in a way that promotes creativity and innovation. This study draws on previous research by P. Vathi （2014） on the topic of ＂A multidimensional-interdisciplinary approach and evaluation of University students＇ creativity, with emphasis on the utilization of statistical analyses＂ in order to assess the influence of education on students＇ creativity

关键词： synergetic education social and solidarity economy creativity innovation

An automatic optimization method for minimizing supporting structures in additive manufacturing

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Advances in Manufacturing 2020年第1期8卷 49-58页

作者： Xiao-Jun Chen Jun-Lei Hu Qing-Long Zhou Constantinus politis Yi sun Institute of Biomedical Manufacturing and Life Quality Engineering State Key Laboratory of Mechanical System and VibrationSchool of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240P.R.China OMFs-IMPATH Research Group Department of Imaging and PathologyFaculty of MedicineKatholieke Universiteit LeuvenLeuvenBelgium Department of Oral and Maxillofacial surgery University Hospitals LeuvenLeuvenBelgium

The amount of supporting structure usage has been a major research topic in layer-based additive manufacturing(AM)over the past years as it leads to increased fabrication time and decreased surface *** studies focused on deformation and topology optimization to eliminate the number of support ***,during the actual fabrication process,the properties of shape and topology are ***,they should not be modified *** this study,we present an optimizer that reduces the number of supporting structures by identifying the prime printing *** rotation,models are projected in each direction in space,and the basis units involved in the generation of support structures are ***,the area of the supporting structures is ***,the prime printing direction with minimal supporting area is obtained through pattern-searching *** results of the experiment demonstrated that the printing area was reduced by up to 60%for some cases,and the surface quality was also improved ***,both the material consumption and fabrication time were decreased in most *** future work,additional factors will be considered,such as the height of the supporting s Xiao-Jun Chen xiaojunchen@*** 1 Institute of Biomedical Manufacturing and Life Quality Engineering,state Key Laboratory of Mechanical system and Vibration,school of Mechanical Engineering,shanghai Jiao Tong University,shanghai 200240,*** 2 OMFs-IMPATH Research Group,Department of Imaging and Pathology,Faculty of Medicine,Katholieke Universiteit Leuven,Leuven,Belgium 3 Department of Oral and Maxillofacial surgery,University Hospitals Leuven,Leuven,Belgium structures and the adhesion locations to improve the efficiency of this optimizer.

关键词： Printing direction Optimization supporting structures

On the Qos Assessment of Video sessions in Heterogeneous 3G-WLAN Networks with seamless and secure Mobility support

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China Communications 2007年第1期4卷 105-119页

作者： Ilias politis Michail Tsagkaropoulos stavros Kotsopoulos Tasos Dagiuklas Peter stavroulakis Dept.of Electrical and Computer Engineering University of Patras26500 Greece Dept.of Telecommunications and Network systems Technical Institute of MessolonghiNafpaktosGreece Technical University of Crete Roumeliotaki 17 str.73100 LentarianaChaniaCreteGreece

Real-time video data transmission is currently emerging as a popular application among mobile users but it is very sensitive to Qos degradation due to packet losses in wireless *** order to achieve service continuity and integrity upon handoffs among heterogeneous networks,provisioning of seamless and secure mobility is ***,in order to reduce the delay and packet losses during vertical handovers we need to employ supportive protocols like context *** this paper we evaluate the Qos of video transmission over a heterogeneous 3G-WLAN *** aggregate video data traffic is represented by a dynamic two-dimensional Markov chain model,which has been evaluated against real video data *** the vertical handover, appropriate AAA handshaking and enhanced mobility management using context transfer have been *** Qos evaluation of video streams was performed based on peak signal-noise ratio(PsNR) measurements,while we analyticallyestimated the number of packet losses during *** results show that both packet loss within the converged network and loss occurrence affecting the perceived video quality is reduced. Moreover,the proposed context transfer scheme minimizes handover delay and the number of lost packet up to 3 times compared to standard AAA handshaking.

关键词： heterogeneous wireless networks multiplexed video traffic RADIUs-AAA,context transfer

secure Packet Video Transmission over Wireless Multimedia sensor Networks

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China Communications 2008年第2期5卷 59-67页

作者： Ilias politis Michail Tsagkaropoulos sofia Gouskou stavros Kotsopoulos Peter stavroulakis Dept.of Electrical and Computer Engineering University of Patras Ericsson Research Technical University of Crete

This paper proposes a packet scheduling scheme thatoptimizing the coded video transmission overmultipath wireless multimedia sensor networks interms of received video distortion and power efficiencyenhances the security aspects of the *** the aggregate transmission rateavailable at the network cannot support the requiredtransmission rate,the scheduling algorithm can selectivelydrop combinations of video packets prior totransmission to adapt the rate of the sender to thelimitations of the wireless channel *** algorithms are *** Baselinescheme utilizes a novel distortion prediction modeland decides upon which packet can be dropped priorto transmission based on the packet’s impact on thevideo *** addition to the bandwidthlimitations,the Power aware packet scheduling is an extension of the Baseline capable of estimating thepower that will be consumed by each node during thetransmission;hence it can control the power consumptionby selectively drop packets of low importanceto the decoded *** results indicatethe efficiency of the proposed scheduling schemein terms of received video distortion(PsNR)andpower consumption.

关键词： Terms-WMsN packet scheduling power consumption video distortion

In-situ formation of Ti-Mo biomaterials by selective laser melting of Ti/Mo and Ti/Mo_(2)C powder mixtures:A comparative study on microstructure,mechanical and wear performance,and thermal mechanisms

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Journal of Materials science & Technology 2022年第20期115卷 81-96页

作者： Qimin shi shoufeng Yang Yi sun Yifei Gu Ben Mercelis shengping Zhong Bart Van Meerbeek Constantinus politis KU Leuven Department of Biomedical SciencesOMFS-IMPATH Research Group&UZ Leuven(University Hospitals Leuven)Oral and Maxillofacial SurgeryKapucijnenvoer 33Leuven 3000Belgium University of southampton Faculty of Engineering and Physical SciencesSouthampton SO171BJUnited Kingdom KU Leuven Department of Oral Health SciencesBIOMAT-Biomaterials Research Group&UZ Leuven(University Hospitals Leuven)DentistryKapucijnenvoer 7Leuven 3000Belgium

Ti-Mo alloys/composites are expected to be the next-generation implant material with low moduli but without toxic/allergic ***,synthesis mechanisms of the Ti-Mo biomaterials in selective Laser Melting(sLM)vary according to raw materials and fundamentally influence material performance,due to inhomogeneous chemical compositions and ***,this work provides a comparative study on microstructure,mechanical and wear performance,and underlying thermal mechanisms of two promising Ti-Mo biomaterials prepared by sLM but through different synthesis mechanisms to offer scientific understanding for creation of ideal metal *** are(i)Ti-7.5 Mo alloys,prepared from a conventional Ti/Mo powder mixture,and(ii)Ti-7.5 Mo-2.4 Ti C composites,in-situ prepared from Ti/Mo_(2)C powder *** reveal that the in-situ Ti-7.5 Mo-2.4 Ti C composites made from Ti/Mo_(2)C powder mixture by sLM can produce 61.4%moreβphase and extra Ti C precipitates(diameter below 229.6 nm)than the Ti-7.5 Mo *** fine Ti C not only contributes to thinner and shorterβcolumnar grains under a large temperature gradient of 51.2 K/μm but also benefits material *** in-situ Ti-7.5 Mo-2.4 Ti C composites produce higher yield strength(980.1±29.8 MPa)and ultimate compressive strength(1561.4±39 MPa)than the Ti-7.5 Mo alloys,increasing by up to 12.1%.However,the fine Ti C with an aspect ratio of 2.71 dominates an unfavourable rise of elastic modulus to 91.9±2 GPa,44.7%higher than the Ti-7.5 Mo alloys,which,nevertheless,is still lower than the modulus of traditional Ti-6 Al-4 ***,Ti C and its homogeneous distribution benefit wear resistance,decreasing the wear rate of the in-situ Ti-7.5 Mo-2.4 Ti C composites to 6.98×10^(-4)mm^3 N^(-1)m^(-1),which is 36%lower than that of the Ti-7.5 Mo ***,although with higher modulus than the Ti-7.5 Mo alloys,the sLM-fabricated in-situ Ti-7.5 Mo-2.4 Ti C composites can expect to provide good biomedical applicati

关键词： selective laser melting(sLM) Titanium Metal matrix composites Microstructures Mechanical properties Wear properties

Validation of a novel imaging approach using multi-slice CT and cone-beam CT to follow-up on condylar remodeling after bimaxillary surgery

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International Journal of Oral science 2017年第3期9卷 139-144页

作者： laura ferreira pinheiro nicolielo jeroen van dessel eman shaheen carolina letelier marina codari constantinus politis ivo lambrichts reinhilde jacobs omfs-impath research group department of imaging and pathologyfaculty of medicineuniversity of leuven and maxillofacial surgery departmentuniversity hospitals leuvenLeuvenBelgium department of oral and maxillofacial radiology university of los andessantiagochileSantiagoChile unit of radiology irccs policlinico san donato MilaneseMilanItaly department of morphology faculty of medicineuniversity of hasseltcampusDiepenbeekBelgium department of dental medicine karolinska institutetHuddingeSweden

The main goal of this study was to introduce a novel three-dimensional procedure to objectively quantify both inner and outer condylar remodelling on preoperative multi-slice computed tomography （MsCT） and postoperative cone-beam computed tomography （CBCT） images. second, the reliability and accuracy of this condylar volume quantification method was assessed. The mandibles of 20 patients （11 female and 9 male） who underwent bimaxillary surgery were semi-automatically extracted from MsCT/CBCT scans and rendered in 3D. The resulting condyles were spatially matched by using an anatomical landmark-based registration procedure. A standardized sphere was created around each condyle, and the condylar bone volume within this selected region of interest was automatically calculated. To investigate the reproducibility of the method, inter- and intra-observer reliability was calculated for assessments made by two experienced radiologists twice five months apart in a set of ten randomly selected patients. To test the accuracy of the bone segmentation, the inner and outer bone structures of one dry mandible, scanned according to the clinical set-up, were compared with the gold standard, micro-CT. Thirty-eight condyles showed a significant （P〈O.05） mean bone volume decrease of 26.4%_ 11.4% （502.9 mm3＋ 268.1 mm3）. No significant effects of side, sex or age were found. Good to excellent （ICC〉 0.6） intra- and inter-observer reliability was observed for both MsCT and CBCT. Moreover, the bone segmentation accuracy was less than one voxel （0.4 mm） for MsCT （0.3 mm __. 0.2 mm） and CBCT （0.4 mm _ 0.3 mm）, thus indicating the clinical potential of this method for objective follow-up in pathological condylar resorption.

关键词： condylar resorption Cone-beam computed tomography mandibular condyle multi-slice computed tomography three-dimensional imaging